METHODS FOR REMOVING METALS FROM SLAGS

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit to U.S. Prov. Appl. No. 63/735,283, filed on Dec. 17, 2024, which is herein incorporated by reference in its entirety.

BACKGROUND

Field

Embodiments of the present disclosure generally relate to processing metal slags and other waste materials, and more specifically, methods for recovering or separating metals from metal slags, black mass, and other materials.

Description of the Related Art

Steel slag is a byproduct of steel production in blast furnaces, electric arc furnaces, and Linz-Donawitz converters. Steel slags and other types of materials contain valuable metals like vanadium, iron, chromium, titanium, manganese, magnesium, and aluminum. Other metal slags, such as zinc slag, copper slag, lead slag, and tin slag, also contain many valuable metals. Various ores and other materials, including waste materials, contain valuable metals. However, extraction processes to remove the valuable metals from the slags, ores, black masses, and other metal-containing waste materials generally use reactors at high temperatures and/or high pressures, which may be energy intense and cost prohibitive, especially when the concentration of the valuable metals is relatively low.

Therefore, a need exists for new methods for recovering metals from metal slags, ores, black masses, and other materials.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the present disclosure may be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.

FIG. 1 is a flowchart depicting a method for removing metals from metal slags, according to one or more embodiments described and discussed herein.

FIG. 2 is a flowchart depicting an exemplary method for removing metals from metal slags, according to one or more embodiments described and discussed herein.

FIG. 3 depicts a pulse mixing reactor which may be used to combine metal slag and acid while producing the acid-coated slag, according to one or more embodiments described and discussed herein.

FIG. 4 is a graph illustrating various types of metal recovery versus different amounts of acid used during methods for removing metals from black masses, according to one or more embodiments described and discussed herein.

FIG. 5 is a graph illustrating various types of metal recovery versus different amounts of acid used during methods for removing metals from a copper-zinc containing slag, according to one or more embodiments described and discussed herein.

To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the Figures. It is contemplated that elements and features of one or more embodiments may be beneficially incorporated in other embodiments.

SUMMARY

Embodiments of the present disclosure generally relate to methods for extracting, recovering, removing, or otherwise separating valuable metals from various metal slags, ores, black masses, other metal sources, and/or other materials. The methods described and discussed herein recover relatively high amounts or yields of valuable metals compared to conventional recovery methods. Also, the methods described and discussed herein recover the without consuming large amounts of energy and expense as conventional recovery methods.

In one or more embodiments, a method of removing metals from a slag is provided and includes exposing a metal slag to an acid, where the metal slag contains one or more metals selected from iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, mixing at least the metal slag and the acid to produce an acid-coated slag, and reacting the metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours. The method also includes separating the metal salts and the residual slag during a separation process. The metal salts contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. One or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt % or greater relative to an original amount of the metal in the metal slag.

In some embodiments, a method of removing metals from a slag is provided and includes exposing a metal slag to a size reduction process, the metal slag contains one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof, and where the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process. The method also includes exposing the metal slag to an acid containing sulfuric acid having a concentration of greater than 90 wt %, mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag), reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours. The method further includes separating the metal salts and the residual slag during a separation process, the metal salts contain one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof. The separation process further includes dissolving the metal salts in water to produce an aqueous metal salt solution, and separating the aqueous metal salt solution from the residual slag. The method also includes exposing the aqueous metal salt solution to a fine filtration process after the separation process, where solid particulate is removed from the aqueous metal salt solution, and the solid particulate contains silica, calcium sulfate, or any combination thereof. The method further includes exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water, the purification process includes a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof. One or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the metal in the metal slag.

In other embodiments, a method of removing metals from a slag is provided and includes exposing a metal slag to an acid, where the metal slag contains one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof, mixing the metal slag, the acid, and a coordinating agent to produce an acid-coated slag, and reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours. The method also includes separating the metal salts and the residual slag during a separation process, where the metal salts contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, and repeating an extraction cycle. The extraction cycle includes exposing the residual slag to the acid, where the residual metal slag contains one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof, mixing the residual slag and the acid to produce an acid-coated residual slag, reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process includes providing the acid-coated residual slag an additional reaction time of at least 24 hours, and separating the additional metal salts and the secondary residual slag during a second separation process, where the additional metal salts contain one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof. The extraction cycle is conducted or repeated 1 time to 5 times. One or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the metal in the metal slag.

In one or more embodiments, a method for removing metals from slags, ores, black masses, and/or other materials is provided and includes exposing a metal slag to an acid, where the metal slag may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, and mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag). The method also includes reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which includes providing the acid-coated slag a reaction time of at least 24 hours, and separating the metal salts and the residual slag during a separation process. The metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

In other embodiments, a method for removing metals from slags, ores, black masses, and/or other materials is provided and includes exposing a metal slag to a size reduction process, where the metal slag may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, and the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process. The method also includes exposing the metal slag to an acid, mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag), and reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which includes providing the acid-coated slag a reaction time of at least 24 hours. The method further includes separating the metal salts and the residual slag during a separation process. The metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. The separation process may also include dissolving the metal salts in water to produce an aqueous metal salt solution, and then separating the aqueous metal salt solution from the residual slag. The method further includes exposing the aqueous metal salt solution to a fine filtration process after the separation process, where solid particulate is removed from the aqueous metal salt solution. The solid particulate may be or contain silica, calcium sulfate, one or more other salts, or any combination thereof. Thereafter, the method also includes exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water. The purification process may include a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof.

In some embodiments, a method for removing metals from a slag is provided and includes exposing a metal slag to an acid and mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag). The metal slag may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. The method also includes reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which includes providing the acid-coated slag a reaction time of at least 24 hours, and separating the metal salts and the residual slag during a separation process. The metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. Thereafter, the method further includes repeating an extraction cycle. The extraction cycle may include exposing the residual slag to the acid, where the residual metal slag may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. The extraction cycle may also include mixing the residual slag and the acid to produce an acid-coated residual slag, reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process which includes providing the acid-coated residual slag an additional reaction time of at least 24 hours. The extraction cycle may further include separating the additional metal salts and the secondary residual slag during a second separation process, where the additional metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. In one or more examples, the extraction cycle is conducted or repeated one time, two times, three times, four times, or five times.

DETAILED DESCRIPTION

Embodiments of the present disclosure generally relates to methods for extracting, recovering, removing, or otherwise separating valuable metals from various metal sources which may be or contain metal slags, ores, black masses, other metal containing waste sources, and/or other materials. In some embodiments, the methods described and discussed herein include exposing the valuable metals within the metal slag to an acid, mixing at least the metal slag and the acid to produce an acid-coated slag, providing time for the acid to react with the valuable metals without heating to produce metal salts, and then separating the metal salts from the residual slag. One or more other metal sources may be similarly treated with or without the metal slag by the methods described and discussed herein.

The methods described and discussed herein recover relatively high amounts or yields of valuable metals compared to conventional recovery methods. Also, the methods described and discussed herein recover the metals without consuming large amounts of energy and expense as compared to conventional recovery methods. Exemplary valuable metals may be or include iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

In one or more embodiments, the methods described and discussed herein provide controlled corrosion for extracting valuable metals from polymetallic slags and introduces a disruptive alternative to conventional hydrometallurgical practices. By leveraging the oxidative dissolution of iron and other metallic phases in slags via concentrated acids (e.g., sulfuric acid), the methods described and discussed herein effectively mobilizes target metals with minimal water and energy input.

Unlike traditional leaching methods that require extensive pretreatment steps, high water consumption, and prolonged residence times, the methods described and discussed herein facilitate metal extraction under ambient conditions without pressure or temperature constraints. The ability to process slags without comminution and the capacity for reprocessing residual material significantly enhances the economic and operational viability. Additionally, the reaction mechanism, which includes corrosion kinetics and the controlled destabilization of the slag matrix, enables the recovery of embedded metals while circumventing the high acid demands typically associated with refractory materials recovered by conventional methods.

Comparative analysis with heap and tank leaching demonstrates that the methods described and discussed herein achieve superior efficiency in acid and water use per ton of treated slag, while drastically reducing process time over traditional processes. Moreover, the methods described and discussed herein align with contemporary environmental and industrial trends by lowering the ecological footprint of secondary metallurgy. Also, the methods described and discussed herein provide controlled corrosion as a scalable, low-footprint, and chemically rational route for metal recovery from metallurgical residues.

In one or more examples, the term black mass refers to the fine dark powder obtained after the mechanical processing of used battery cells during the recycling of electronic waste, particularly spent lithium-ion batteries. Once the batteries are discharged and shredded, the casings, current collectors, and plastics are separated, leaving behind a heterogeneous mixture composed primarily of the electrode materials. This fraction, known as black mass, contains the valuable critical elements, including lithium, copper, cobalt, nickel, manganese, or any combination thereof, as well as graphite originating from the anode. The methods and processes described and discussed herein may be used on black mass and other materials in the same way or substantially similar way as on the metal slags.

FIG. 1 is a flowchart depicting a process or method 100 for extracting, recovering, removing, or otherwise separating valuable metals from various metal slags, ores, black masses, other metal sources, and/or other materials, according to one or more embodiments described and discussed herein. In one or more embodiments, the method 100 includes exposing a metal slag to an acid (at operation 110). In some examples, the metal slag may contain one or more valuable metals, such as iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof. The method also includes mixing, coating, or otherwise combining the metal slag and the acid to produce an acid-coated slag (at operation 120). The method further includes reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process (at operation 130). The reaction process includes providing the acid-coated slag a reaction time of at least 24 hours to produce the metal salts and the residual slag. The method also includes separating the metal salts and the residual slag during a separation process (at operation 140). The valuable metals are recovered as the metal salts and may contain, in some examples, one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

The metal sources of the valuable metals may be or contain one or more of metal slags, ores, black masses, other metal sources, and/or other materials. Exemplary metal sources or metal slags may be or contain one or more of steel slag, zinc slag, copper slag, copper and zinc slag, lead slag, zinc and lead slag, tin slag, antimony slag, nickel slag, uranium slag, copper ore, iron ore, tungsten ore, arsenic ore, or any combination thereof. The types of valuable metals recovered depend upon the types of metal sources processed or otherwise used in the methods described and discussed herein. The metal sources, metal slags, and/or metal ores may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, uranium, thorium, or any combination thereof.

In one or more embodiments, prior to exposing the metal slag to the acid at operation 110, the metal slag may be exposed to one or more size reduction processes. For example, the size reduction process used to reduce the particle size of the metal source or metal slag may be or include one or more of techniques, such as milling, grinding, smashing, crushing, or any combination thereof. In some examples, the metal source or metal slag is reduced to a particle size of about P80 0.25 inch or less during the size reduction process.

At operation 110, the metal slag and the acid are combined. In one or more examples, the metal slag is exposed to the acid by spraying, pouring, or otherwise introducing the acid onto the metal slag. The acid may be or contain one or more of sulfuric acid, hydrochloric acid, nitric acid, aqua regia, oxalic acid, citric acid, salts thereof, or any combination thereof. In one or more examples, the acid may be or contain concentrated sulfuric acid, such as at a concentration of greater than 80 wt %, greater than 85 wt %, or greater than 90 wt %, such as about 95 wt % or greater, about 96 wt % or greater, about 97 wt % or greater, about 98 wt % or greater, or about 98.5 wt % or greater. In some examples, the acid may be or include aqua regia which may be a solution of nitrohydrochloric acid formed from a mixture of hydrochloric acid and nitric acid, for example, a mixture of about 3:1 of hydrochloric acid to nitric acid.

In one or more embodiments, the acid may be or contain concentrated sulfuric acid having a concentration in a range from about or greater than 80 wt %, about or greater than 85 wt %, about or greater than 86 wt %, or about or greater than 88 wt % to about or greater than 90 wt %, about or greater than 92 wt %, about or greater than 94 wt %, about or greater than 95 wt %, about or greater than 96 wt %, about or greater than 97 wt %, about or greater than 98 wt %, about or greater than 98.5 wt %, about or greater than 99 wt %, about or 100 wt %. For example, the acid may be or contain concentrated sulfuric acid having a concentration in a range from about 80 wt % to about 100 wt %, about 80 wt % to about 99 wt %, about 80 wt % to about 98.5 wt %, about 80 wt % to about 98 wt %, about 80 wt % to about 97 wt %, about 80 wt % to about 96 wt %, about 80 wt % to about 95 wt %, about 80 wt % to about 94 wt %, about 80 wt % to about 92 wt %, about 80 wt % to about 90 wt %, about 80 wt % to about 88 wt %, about 80 wt % to about 86 wt %, about 80 wt % to about 85 wt %, about 88 wt % to about 100 wt %, about 88 wt % to about 99 wt %, about 88 wt % to about 98.5 wt %, about 88 wt % to about 98 wt %, about 88 wt % to about 97 wt %, about 88 wt % to about 96 wt %, about 88 wt % to about 95 wt %, about 88 wt % to about 94 wt %, about 88 wt % to about 92 wt %, about 88 wt % to about 90 wt %, about 90 wt % to about 100 wt %, about 90 wt % to about 99 wt %, about 90 wt % to about 98.5 wt %, about 90 wt % to about 98 wt %, about 90 wt % to about 97 wt %, about 90 wt % to about 96 wt %, about 90 wt % to about 95 wt %, about 90 wt % to about 94 wt %, about 90 wt % to about 92 wt %, about 95 wt % to about 100 wt %, about 95 wt % to about 99 wt %, about 95 wt % to about 98.5 wt %, about 95 wt % to about 98 wt %, about 95 wt % to about 97 wt %, or about 95 wt % to about 96 wt %.

The acid may be combined with the metal slag at an amount in a range from about 1 wt %, about 2 wt %, about 2.5 wt %, about 3 wt %, about 4 wt %, about 5 wt %, about 6 wt %, about 7.5 wt %, about 8 wt %, about 10 wt %, about 12 wt %, about 14 wt %, or about 15 wt % to about 18 wt %, about 20 wt %, about 22 wt %, about 25 wt %, about 28 wt %, about 30 wt %, about 35 wt %, about 40 wt %, about 45 wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, about 70 wt %, about 75 wt %, about 80 wt %, about 90 wt %, about 100 wt %, about 120 wt %, or greater relative to weight of the metal slag. For example, the acid may be combined with the metal slag at an amount in a range from about 1 wt % to about 100 wt %, about 1 wt % to about 90 wt %, about 1 wt % to about 80 wt %, about 1 wt % to about 70 wt %, about 1 wt % to about 60 wt %, about 2.5 wt % to about 70 wt %, about 5 wt % to about 70 wt %, about 7.5 wt % to about 70 wt %, about 10 wt % to about 70 wt %, about 12 wt % to about 70 wt %, about 15 wt % to about 70 wt %, about 20 wt % to about 70 wt %, about 25 wt % to about 70 wt %, about 30 wt % to about 70 wt %, about 35 wt % to about 70 wt %, about 40 wt % to about 70 wt %, about 45 wt % to about 70 wt %, about 50 wt % to about 70 wt %, about 55 wt % to about 70 wt %, about 60 wt % to about 70 wt %, about 65 wt % to about 70 wt %, about 2.5 wt % to about 50 wt %, about 5 wt % to about 50 wt %, about 7.5 wt % to about 50 wt %, about 10 wt % to about 50 wt %, about 12 wt % to about 50 wt %, about 15 wt % to about 50 wt %, about 20 wt % to about 50 wt %, about 25 wt % to about 50 wt %, about 30 wt % to about 50 wt %, about 35 wt % to about 50 wt %, about 40 wt % to about 50 wt %, about 2.5 wt % to about 35 wt %, about 5 wt % to about 35 wt %, about 7.5 wt % to about 35 wt %, about 10 wt % to about 35 wt %, about 12 wt % to about 35 wt %, about 15 wt % to about 35 wt %, about 20 wt % to about 35 wt %, about 25 wt % to about 35 wt %, about 30 wt % to about 35 wt %, about 2.5 wt % to about 25 wt %, about 5 wt % to about 25 wt %, about 7.5 wt % to about 25 wt %, about 10 wt % to about 25 wt %, about 12 wt % to about 25 wt %, about 15 wt % to about 25 wt %, about 20 wt % to about 25 wt %, about 2.5 wt % to about 20 wt %, about 5 wt % to about 20 wt %, about 7.5 wt % to about 20 wt %, about 10 wt % to about 20 wt %, about 12 wt % to about 20 wt %, about 15 wt % to about 20 wt %, about 18 wt % to about 20 wt %, about 5 wt % to about 30 wt %, or about 10 wt % to about 15 wt % relative to weight of the metal slag.

In one or more examples, the acid is mixed with the metal slag to produce the acid-coated slag at an amount or concentration in a range from about 2.5 wt % to about 50 wt %, about 5 wt % to about 30 wt %, about 7.5 wt % to about 25 wt %, or about 10 wt % to about 15 wt % relative to the weight of the metal slag. In other examples, the acid is mixed with the metal slag to produce the acid-coated slag at an amount or concentration in a range from about 10 wt % to about 120 wt %, about 10 wt % to about 100 wt %, about 10 wt % to about 80 wt %, or about 10 wt % to about 60 wt % relative to the weight of the metal slag. In some examples, the acid is mixed with the metal slag to produce the acid-coated slag at an amount or concentration in a range from about 20 wt % to about 100 wt %, about 30 wt % to about 90 wt %, about 40 wt % to about 80 wt %, about 50 wt % to about 70 wt %, or about 55 wt % to about 65 wt % relative to the weight of the metal slag.

In some embodiments, water can be added to the metal slag and/or the acid-coated slag at operation 110 and/or at operation 120. In some examples, the acid-coated slag may contain one or more coordinating agents. In other examples, the acid-coated slag may be completely free or substantially of the coordinating agent. In one or more examples, the water may be combined or otherwise added with the metal slag and the acid to produce the acid-coated slag. In some examples, the water may be combined or otherwise added with the metal slag and/or the acid prior to producing the acid-coated slag. In other examples, the water may be combined and/or added with the metal slag and the acid when producing the acid-coated slag. In some examples, the water is combined with the acid-coated slag during the reaction process. In one or more examples, the water may be combined or otherwise added with the acid-coated slag during the reaction process.

The water concentration, also known as the humidity or moisture concentration, is the weight amount of water relative to the weight of the metal slag. The water may be combined with the metal slag at an amount in a range from about 0.5 wt %, about 0.8 wt %, about 1 wt %, about 1.2 wt %, about 1.5 wt %, about 1.8 wt %, about 2 wt %, about 2.2 wt %, about 2.5 wt %, about 2.8 wt %, about 3 wt %, about 3.2 wt %, about 3.5 wt %, about 3.8 wt %, about 4 wt %, about 4.2 wt %, about 4.5 wt %, about 4.8 wt %, about 5 wt %, about 6 wt %, about 7 wt %, about 8 wt %, about 9 wt %, about 10 wt %, about 12 wt %, about 14 wt %, about 15 wt %, about 15.5 wt %, about 16 wt %, about 16.5 wt %, about 17 wt %, about 17.5 wt %, about 18 wt %, about 20 wt %, or greater relative to weight of the metal slag. For example, the water may be combined with the metal slag at an amount in a range from about 0.5 wt % to about 20 wt %, about 0.5 wt % to about 18 wt %, about 0.5 wt % to about 16 wt %, about 0.5 wt % to about 15 wt %, about 0.5 wt % to about 14 wt %, about 0.5 wt % to about 12 wt %, about 0.5 wt % to about 10 wt %, about 1 wt % to about 20 wt %, about 1 wt % to about 18 wt %, about 1 wt % to about 17 wt %, about 1 wt % to about 16 wt %, about 1 wt % to about 15 wt %, about 1 wt % to about 14 wt %, about 1 wt % to about 12 wt %, about 1 wt % to about 10 wt %, about 1 wt % to about 5 wt %, about 1 wt % to about 4 wt %, about 1 wt % to about 3.5 wt %, about 1 wt % to about 3 wt %, about 1 wt % to about 2.8 wt %, about 1 wt % to about 2.5 wt %, about 1 wt % to about 2.2 wt %, about 1 wt % to about 2 wt %, about 1 wt % to about 1.8 wt %, about 1 wt % to about 1.5 wt %, about 1 wt % to about 1.2 wt %, about 2 wt % to about 20 wt %, about 2 wt % to about 18 wt %, about 2 wt % to about 17 wt %, about 2 wt % to about 16 wt %, about 2 wt % to about 15 wt %, about 2 wt % to about 14 wt %, about 2 wt % to about 12 wt %, about 2 wt % to about 10 wt %, about 2 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3.5 wt %, about 2 wt % to about 3 wt %, about 2 wt % to about 2.8 wt %, about 2 wt % to about 2.5 wt %, about 2 wt % to about 2.2 wt %, about 3 wt % to about 20 wt %, about 3 wt % to about 18 wt %, about 3 wt % to about 17 wt %, about 3 wt % to about 16 wt %, about 3 wt % to about 15 wt %, about 3 wt % to about 14 wt %, about 3 wt % to about 12 wt %, about 3 wt % to about 10 wt %, about 3 wt % to about 5 wt %, about 3 wt % to about 4 wt %, about 3 wt % to about 3.5 wt %, about 3 wt % to about 3.2 wt %, about 4 wt % to about 20 wt %, about 4 wt % to about 18 wt %, about 4 wt % to about 16 wt %, about 4 wt % to about 15 wt %, about 4 wt % to about 14 wt %, about 4 wt % to about 12 wt %, about 4 wt % to about 10 wt %, about 4 wt % to about 8 wt %, about 4 wt % to about 6 wt %, about 4 wt % to about 5 wt %, about 5 wt % to about 20 wt %, about 6 wt % to about 20 wt %, about 8 wt % to about 20 wt %, about 10 wt % to about 20 wt %, about 12 wt % to about 20 wt %, about 14 wt % to about 20 wt %, about 15 wt % to about 20 wt %, about 16 wt % to about 20 wt %, about 17 wt % to about 20 wt %, about 18 wt % to about 20 wt %, about 15 wt % to about 18 wt %, about 15 wt % to about 17 wt %, or about 15 wt % to about 16 wt % relative to weight of the metal slag.

In some examples, a water concentration of the acid-coated slag in a range from about 0.5 wt % to about 10 wt %, about 1 wt % to about 10 wt %, about 1 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, or about 3 wt % to about 4 wt % during the reaction process, wherein the water concentration is relative to the weight of the metal slag. In other examples, a water concentration of the acid-coated slag in a range from about 2 wt % to about 20 wt %, about 3 wt % to about 18 wt %, about 5 wt % to about 16 wt %, about 8 wt % to about 15 wt %, about 10 wt % to about 15 wt %, about 12 wt % to about 18 wt %, about 15 wt % to about 18 wt %, about 12 wt % to about 15 wt %, or about 14 wt % to about 14 wt % during the reaction process, wherein the water concentration is relative to the weight of the metal slag.

In one or more embodiments, the metal slag, the metal slag and/or the acid-coated slag may contain one or more coordinating agents (e.g., complexing agents). In some examples, the coordinating agent provides greater degrees of metal separation from the slag or other materials therefrom relative to similar separations or extractions without the use of a coordinating agent. As such, the use of the coordinating agent may provide an increased yield select metals recovered from the slag. The coordinating agent may be or include one or more alkaline metal salts (e.g., containing Na, K, Cs), one or more alkaline earth metal salts (e.g., containing Be, Mg, Ca, Ba), one or more halide salts (e.g., containing F, Cl, Br, I), one or more alkaline metal halide salts, one or more sulfates, one or more oxides, one or more organic acids (including carboxylic acids, polyprotic carboxylic acids, and/or salts thereof), one or more organic sulfonic acids, ammonium salts and complexes, organic amino salts and complexes, complexes thereof, salts thereof, hydrates thereof, or any combination thereof. Exemplary coordinating agents may be or include sodium chloride, sodium bromide, sodium iodide, potassium chloride, calcium chloride, calcium sulfate, magnesium sulfate, acetic acid, sodium acetate, potassium acetate, citric acid, sodium citrate, potassium citrate, calcium citrate, magnesium citrate, zinc citrate, urea, thiourea, complexes thereof, salts thereof, hydrates thereof, or any combination thereof.

In some embodiments, at operation 110 and/or at operation 120, the metal slag and the acid may be combined with one or more coordinating agents. In one or more examples, the metal slag and the coordinating agent may be combined, and then exposed to the acid by spraying, pouring, or otherwise introducing the acid onto the combination of the metal slag and the coordinating agent. In some examples, the metal slag and the acid may be combined and then the coordinating agent may be added into the mixture. In other examples, the coordinating agent and the acid may be combined and then the metal slag may be added into the mixture. In one or more examples, the metal slag, the coordinating agent, and the acid may be combined at the same time to produce a mixture.

In one or more embodiments, the coordinating agent may be in liquid form, such as being dissolved, suspended, or otherwise contained in water and/or one or more aqueous solvents. The liquid form of the coordinating agent may be a solution, a suspension, or a combination thereof. Exemplary solvents may be or include water, salt water, one or more aqueous solutions, one or more aqueous suspensions, or any combination thereof.

In liquid form, the concentration of the coordinating agent to the water or solvent may be in a range from about 1% w/v (percent by weight per volume), about 2% w/V, about 4% w/v, about 5% w/v, about 6% w/v, about 8% w/v, or about 10% w/v to about 12% w/v, about 15% w/v, about 18% w/v, about 20% w/v, about 22% w/v, about 25% w/V, about 28% w/v, about 30% w/v, about 35% w/v, about 40% w/v, about 45% w/v, about 50% w/v, or greater. For example, the concentration of the coordinating agent to the water or solvent may be in a range from about 1% w/v to about 50% w/v, about 5% w/v to about 50% w/v, about 5% w/v to about 40% w/v, about 5% w/v to about 35% w/v, about 5% w/v to about 30% w/v, about 5% w/v to about 25% w/v, about 5% w/v to about 20% w/v, about 5% w/v to about 15% w/v, about 5% w/v to about 12% w/v, about 5% w/v to about 10% w/v, about 5% w/v to about 8% w/v, about 10% w/v to about 50% w/v, about 10% w/v to about 40% w/v, about 10% w/v to about 35% w/v, about 10% w/v to about 30% w/v, about 10% w/v to about 25% w/v, about 10% w/v to about 20% w/v, about 10% w/v to about 15% w/v, about 10% w/v to about 12% w/v, about 15% w/v to about 50% w/v, about 15% w/v to about 40% w/v, about 15% w/v to about 35% w/v, about 15% w/v to about 30% w/v, about 15% w/v to about 25% w/v, about 15% w/v to about 20% w/v, or about 15% w/v to about 18% w/v.

In some embodiments, the coordinating agent in liquid form may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 10 mL, about 15 mL, about 20 mL, about 25 mL, about 30 mL, about 40 mL, about 50 mL, about 60 mL, about 70 mL, about 80 mL, about 90 mL, about 100 mL, about 120 mL, about 135 mL, about 150 mL, about 180 mL, about 200 mL, about 250 mL, about 300 mL, about 400 mL, about 500 mL, or greater per 1 kg of the metal slag. For example, the coordinating agent in liquid form may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 10 mL to about 500 mL, about 10 mL to about 400 mL, about 10 mL to about 300 mL, about 10 mL to about 250 mL, about 10 mL to about 200 mL, about 10 mL to about 150 mL, about 10 mL to about 120 mL, about 10 mL to about 100 mL, about 10 mL to about 80 mL, about 10 mL to about 60 mL, about 10 mL to about 50 mL, about 10 mL to about 40 mL, about 10 mL to about 25 mL, about 50 mL to about 500 mL, about 50 mL to about 400 mL, about 50 mL to about 300 mL, about 50 mL to about 250 mL, about 50 mL to about 200 mL, about 50 mL to about 150 mL, about 50 mL to about 120 mL, about 50 mL to about 100 mL, about 50 mL to about 80 mL, about 50 mL to about 60 mL, about 100 mL to about 500 mL, about 100 mL to about 400 mL, about 100 mL to about 300 mL, about 100 mL to about 250 mL, about 100 mL to about 200 mL, about 100 mL to about 180 mL, about 100 mL to about 150 mL, about 100 mL to about 120 mL, about 200 mL to about 500 mL, about 200 mL to about 400 mL, about 200 mL to about 300 mL, about 200 mL to about 250 mL, or about 200 mL to about 220 mL per 1 kg of the metal slag.

In one or more examples, the coordinating agent in liquid form contains sodium chloride in water at a concentration in a range from about 1% w/v to about 50% w/v, which is added to the metal slag at a concentration in a range from about 10 mL to about 500 mL per 1 kg of the metal slag. In other examples, the coordinating agent in liquid form contains sodium chloride in water at a concentration in a range from about 5% w/v to about 25% w/v, which is added to the metal slag at a concentration in a range from about 50 mL to about 100 mL per 1 kg of the metal slag. In some examples, the coordinating agent in liquid form contains sodium chloride in water at a concentration in a range from about 10% w/v to about 20% w/v, which is added to the metal slag at a concentration in a range from about 60 mL to about 80 mL per 1 kg of the metal slag.

The coordinating agent may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 0.01 wt %, about 0.05 wt %, about 0.1 wt %, about 0.15 wt %, about 0.2 wt %, about 0.22 wt %, about 0.25 wt %, about 0.3 wt %, about 0.35 wt %, about 0.4 wt %, about 0.45 wt %, about 0.5 wt %, about 0.55 wt %, or about 0.6 wt % to about 0.65 wt %, about 0.7 wt %, about 0.75 wt %, about 0.8 wt %, about 0.85 wt %, about 0.9 wt %, about 0.95 wt %, about 1 wt %, about 1.05 wt %, about 1.1 wt %, about 1.2 wt %, about 1.3 wt %, about 1.4 wt %, about 1.5 wt %, about 1.6 wt %, about 1.8 wt %, about 2 wt %, about 2.2 wt %, about 2.4 wt %, about 2.5 wt %, about 2.6 wt %, about 2.8 wt %, about 3 wt %, about 3.5 wt %, about 4 wt %, about 4.5 wt %, about 5 wt %, or greater relative to weight of the metal slag. For example, the coordinating agent may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 0.1 wt % to about 5 wt %, about 0.1 wt % to about 4 wt %, about 0.1 wt % to about 3 wt %, about 0.1 wt % to about 2.5 wt %, about 0.1 wt % to about 2 wt %, about 0.1 wt % to about 1.8 wt %, about 0.1 wt % to about 1.5 wt %, about 0.1 wt % to about 1.2 wt %, about 0.1 wt % to about 1 wt %, about 0.1 wt % to about 0.8 wt %, about 0.1 wt % to about 0.6 wt %, about 0.1 wt % to about 0.5 wt %, about 0.1 wt % to about 0.4 wt %, about 0.1 wt % to about 0.3 wt %, about 0.1 wt % to about 0.25 wt %, about 0.1 wt % to about 0.2 wt %, about 0.25 wt % to about 5 wt %, about 0.25 wt % to about 4 wt %, about 0.25 wt % to about 3 wt %, about 0.25 wt % to about 2.5 wt %, about 0.25 wt % to about 2 wt %, about 0.25 wt % to about 1.8 wt %, about 0.25 wt % to about 1.5 wt %, about 0.25 wt % to about 1.2 wt %, about 0.25 wt % to about 1 wt %, about 0.25 wt % to about 0.8 wt %, about 0.25 wt % to about 0.6 wt %, about 0.25 wt % to about 0.5 wt %, about 0.25 wt % to about 0.4 wt %, about 0.25 wt % to about 0.3 wt %, about 0.5 wt % to about 5 wt %, about 0.5 wt % to about 4 wt %, about 0.5 wt % to about 3 wt %, about 0.5 wt % to about 2.5 wt %, about 0.5 wt % to about 2 wt %, about 0.5 wt % to about 1.8 wt %, about 0.5 wt % to about 1.5 wt %, about 0.5 wt % to about 1.2 wt %, about 0.5 wt % to about 1 wt %, about 0.5 wt % to about 0.8 wt %, about 0.5 wt % to about 0.6 wt %, about 0.8 wt % to about 5 wt %, about 0.8 wt % to about 4 wt %, about 0.8 wt % to about 3 wt %, about 0.8 wt % to about 2.5 wt %, about 0.8 wt % to about 2 wt %, about 0.8 wt % to about 1.8 wt %, about 0.8 wt % to about 1.5 wt %, about 0.8 wt % to about 1.2 wt %, about 0.8 wt % to about 1 wt %, about 1 wt % to about 5 wt %, about 1 wt % to about 4 wt %, about 1 wt % to about 3 wt %, about 1 wt % to about 2.5 wt %, about 1 wt % to about 2 wt %, about 1 wt % to about 1.8 wt %, about 1 wt % to about 1.5 wt %, about 1 wt % to about 1.2 wt %, about 1.5 wt % to about 5 wt %, about 1.5 wt % to about 4 wt %, about 1.5 wt % to about 3 wt %, about 1.5 wt % to about 2.5 wt %, about 1.5 wt % to about 2 wt %, about 1.5 wt % to about 1.8 wt %, about 1.5 wt % to about 1.6 wt %, about 2 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, or about 2 wt % to about 2.5 wt %, relative to weight of the metal slag.

At operation 120, the metal slag and the acid and optionally the coordinating agent may be rotated, tumbled, mixed, or otherwise combined to produce the acid-coated slag. The metal slag and the acid and optionally the coordinating agent may be mixed in or by a rotating mixer, a cylinder mixer, a drum mixer, a helix mixer, a tumbler, rotating blades, an oscillator, a pulse-mixing reactor, other types of mixers, or any combination thereof. In some examples, water, one or more other aqueous solvents, and/or one or more coordinating agents may be added along with the acid and the metal slag.

In one or more embodiments, the method 100 includes combining one or more coordinating agents with the metal slag and the acid to produce the acid-coated slag. In one or more examples, the coordinating agent may be combined with the metal slag and/or the acid prior to producing the acid-coated slag. In other examples, the coordinating agent may be combined with the metal slag and the acid when producing the acid-coated slag. In some examples, the coordinating agent may be combined with the acid-coated slag during the reaction process. In one or more examples, the coordinating agent may be or include one or more alkaline metal halide salts (e.g., NaCl). The coordinating agent may have a concentration in a range from about 0.1 wt % to about 5 wt %, relative to weight of the metal slag.

In one or more embodiments, one or more oxidizers may be added to or otherwise combined the metal slag, the acid, and/or optional the coordinating agent and also rotated, tumbled, mixed, or otherwise combined to produce the acid-coated slag. In some examples, the acid-coated slag contains the metal slag, the acid, optional the coordinating agent, and the oxidizer. In other examples, the acid-coated slag contains the metal slag, the acid, optional the coordinating agent, and is free or substantially free of the oxidizer. The oxidizer may be used to oxidize the metal ions of the metals (e.g., Cu) in the metal slag to a higher oxidation state. The oxidizer may be used to provide a greater concentration of recovered metals. Exemplary oxidizers may be or contain one or more hypochlorites, one or more peroxides (e.g., hydrogen peroxide, calcium peroxide, one or more organic peroxides), one or more chlorates (e.g., sodium chlorate), one or more percarbonates (e.g., sodium percarbonate), one or more organic oxidants (e.g., peracetic acid, benzoyl peroxide), any salt thereof, or any combination thereof. Exemplary chlorites may be or contain sodium hypochlorite (NaClO), lithium hypochlorite (LiClO), potassium hypochlorite (KClO), calcium hypochlorite (Ca(ClO)₂), other salts thereof, or any combination thereof.

In one or more embodiments, the oxidizer may be in liquid form, such as being dissolved, suspended, or otherwise contained in water and/or one or more aqueous solvents. The liquid form of the oxidizer may be a solution, a suspension, or a combination thereof. Exemplary solvents may be or include water, salt water, one or more aqueous solutions, one or more aqueous suspensions, or any combination thereof.

In liquid form, the concentration of the oxidizer to the water or solvent may be in a range from about 1% w/v, about 2% w/v, about 4% w/v, about 5% w/v, about 6% w/v, about 8% w/v, or about 10% w/v to about 12% w/v, about 15% w/v, about 18% w/v, about 20% w/v, about 22% w/v, about 25% w/v, about 28% w/v, about 30% w/v, about 35% w/v, about 40% w/v, about 45% w/v, about 50% w/v, or greater. For example, the concentration of the oxidizer to the water or solvent may be in a range from about 1% w/v to about 50% w/v, about 5% w/v to about 50% w/v, about 5% w/v to about 40% w/v, about 5% w/v to about 35% w/v, about 5% w/v to about 30% w/v, about 5% w/v to about 25% w/v, about 5% w/v to about 20% w/v, about 5% w/v to about 15% w/v, about 5% w/v to about 12% w/v, about 5% w/v to about 10% w/v, about 5% w/v to about 8% w/v, about 10% w/v to about 50% w/v, about 10% w/v to about 40% w/v, about 10% w/v to about 35% w/v, about 10% w/v to about 30% w/v, about 10% w/v to about 25% w/v, about 10% w/v to about 20% w/v, about 10% w/v to about 15% w/v, about 10% w/v to about 12% w/v, about 15% w/v to about 50% w/v, about 15% w/v to about 40% w/v, about 15% w/v to about 35% w/v, about 15% w/v to about 30% w/v, about 15% w/v to about 25% w/v, about 15% w/v to about 20% w/v, or about 15% w/v to about 18% w/V.

In some embodiments, the oxidizer in liquid form may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 10 mL, about 15 mL, about 20 mL, about 25 mL, about 30 mL, about 40 mL, about 50 mL, about 60 mL, about 70 mL, about 80 mL, about 90 mL, about 100 mL, about 120 mL, about 135 mL, about 150 mL, about 180 mL, about 200 mL, about 250 mL, about 300 mL, about 400 mL, about 500 mL, or greater per 1 kg of the metal slag. For example, the oxidizer in liquid form may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 10 mL to about 500 mL, about 10 mL to about 400 mL, about 10 mL to about 300 mL, about 10 mL to about 250 mL, about 10 mL to about 200 mL, about 10 mL to about 150 mL, about 10 mL to about 120 mL, about 10 mL to about 100 mL, about 10 mL to about 80 mL, about 10 mL to about 60 mL, about 10 mL to about 50 mL, about 10 mL to about 40 mL, about 10 mL to about 25 mL, about 50 mL to about 500 mL, about 50 mL to about 400 mL, about 50 mL to about 300 mL, about 50 mL to about 250 mL, about 50 mL to about 200 mL, about 50 mL to about 150 mL, about 50 mL to about 120 mL, about 50 mL to about 100 mL, about 50 mL to about 80 mL, about 50 mL to about 60 mL, about 100 mL to about 500 mL, about 100 mL to about 400 mL, about 100 mL to about 300 mL, about 100 mL to about 250 mL, about 100 mL to about 200 mL, about 100 mL to about 180 mL, about 100 mL to about 150 mL, about 100 mL to about 120 mL, about 200 mL to about 500 mL, about 200 mL to about 400 mL, about 200 mL to about 300 mL, about 200 mL to about 250 mL, or about 200 mL to about 220 mL per 1 kg of the metal slag.

In one or more examples, the oxidizer (e.g., hydrogen peroxide) is in water at a concentration in a range from about 5% w/v to about 50% w/v, which is added to the metal slag at a concentration in a range from about 10 mL to about 500 mL per 1 kg of the metal slag. In other examples, the oxidizer (e.g., hydrogen peroxide) is in water at a concentration in a range from about 20% w/v to about 40% w/v, which is added to the metal slag at a concentration in a range from about 50 mL to about 100 mL per 1 kg of the metal slag. In some examples, the oxidizer (e.g., hydrogen peroxide) is in water at a concentration in a range from about 25% w/v to about 30% w/v, which is added to the metal slag at a concentration in a range from about 60 mL to about 80 mL per 1 kg of the metal slag.

The oxidizer may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 0.01 wt %, about 0.05 wt %, about 0.08 wt %, about 0.1 wt %, about 0.15 wt %, about 0.2 wt %, about 0.22 wt %, about 0.25 wt %, about 0.3 wt %, about 0.35 wt %, about 0.4 wt %, about 0.45 wt %, about 0.5 wt %, about 0.55 wt %, or about 0.6 wt % to about 0.65 wt %, about 0.7 wt %, about 0.75 wt %, about 0.8 wt %, about 0.85 wt %, about 0.9 wt %, about 0.95 wt %, about 1 wt %, about 1.05 wt %, about 1.1 wt %, about 1.2 wt %, about 1.3 wt %, about 1.4 wt %, about 1.5 wt %, about 1.6 wt %, about 1.8 wt %, about 2 wt %, about 2.2 wt %, about 2.4 wt %, about 2.5 wt %, about 2.6 wt %, about 2.8 wt %, about 3 wt %, about 3.5 wt %, about 4 wt %, about 4.5 wt %, about 5 wt %, or greater relative to weight of the metal slag. For example, the oxidizer may be combined with or otherwise contained in the metal slag or the acid-coated slag at an amount or concentration in a range from about 0.1 wt % to about 5 wt %, about 0.1 wt % to about 4 wt %, about 0.1 wt % to about 3 wt %, about 0.1 wt % to about 2.5 wt %, about 0.1 wt % to about 2 wt %, about 0.1 wt % to about 1.8 wt %, about 0.1 wt % to about 1.5 wt %, about 0.1 wt % to about 1.2 wt %, about 0.1 wt % to about 1 wt %, about 0.1 wt % to about 0.8 wt %, about 0.1 wt % to about 0.6 wt %, about 0.1 wt % to about 0.5 wt %, about 0.1 wt % to about 0.4 wt %, about 0.1 wt % to about 0.3 wt %, about 0.1 wt % to about 0.25 wt %, about 0.1 wt % to about 0.2 wt %, about 0.25 wt % to about 5 wt %, about 0.25 wt % to about 4 wt %, about 0.25 wt % to about 3 wt %, about 0.25 wt % to about 2.5 wt %, about 0.25 wt % to about 2 wt %, about 0.25 wt % to about 1.8 wt %, about 0.25 wt % to about 1.5 wt %, about 0.25 wt % to about 1.2 wt %, about 0.25 wt % to about 1 wt %, about 0.25 wt % to about 0.8 wt %, about 0.25 wt % to about 0.6 wt %, about 0.25 wt % to about 0.5 wt %, about 0.25 wt % to about 0.4 wt %, about 0.25 wt % to about 0.3 wt %, about 0.5 wt % to about 5 wt %, about 0.5 wt % to about 4 wt %, about 0.5 wt % to about 3 wt %, about 0.5 wt % to about 2.5 wt %, about 0.5 wt % to about 2 wt %, about 0.5 wt % to about 1.8 wt %, about 0.5 wt % to about 1.5 wt %, about 0.5 wt % to about 1.2 wt %, about 0.5 wt % to about 1 wt %, about 0.5 wt % to about 0.8 wt %, about 0.5 wt % to about 0.6 wt %, about 0.8 wt % to about 5 wt %, about 0.8 wt % to about 4 wt %, about 0.8 wt % to about 3 wt %, about 0.8 wt % to about 2.5 wt %, about 0.8 wt % to about 2 wt %, about 0.8 wt % to about 1.8 wt %, about 0.8 wt % to about 1.5 wt %, about 0.8 wt % to about 1.2 wt %, about 0.8 wt % to about 1 wt %, about 1 wt % to about 5 wt %, about 1 wt % to about 4 wt %, about 1 wt % to about 3 wt %, about 1 wt % to about 2.5 wt %, about 1 wt % to about 2 wt %, about 1 wt % to about 1.8 wt %, about 1 wt % to about 1.5 wt %, about 1 wt % to about 1.2 wt %, about 1.5 wt % to about 5 wt %, about 1.5 wt % to about 4 wt %, about 1.5 wt % to about 3 wt %, about 1.5 wt % to about 2.5 wt %, about 1.5 wt % to about 2 wt %, about 1.5 wt % to about 1.8 wt %, about 1.5 wt % to about 1.6 wt %, about 2 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, or about 2 wt % to about 2.5 wt %, relative to weight of the metal slag.

At operation 120, the metal slag and the acid and optionally the coordinating agent and/or the oxidizer may be rotated, tumbled, mixed, or otherwise combined to produce the acid-coated slag. The metal slag and the acid and optionally the coordinating agent and/or the oxidizer may be mixed in or by a rotating mixer, a cylinder mixer, a drum mixer, a helix mixer, a tumbler, rotating blades, an oscillator, a pulse-mixing reactor, other types of mixers, or any combination thereof. In some examples, water, one or more other aqueous solvents, and/or optionally one or more coordinating agents and/or optionally one or more oxidizers may be added along with the acid and the metal slag.

In one or more embodiments, the method 100 includes combining one or more oxidizers with the metal slag and the acid to produce the acid-coated slag. In one or more examples, the oxidizer may be combined with the metal slag and/or the acid prior to producing the acid-coated slag. In other examples, the oxidizer may be combined with the metal slag and the acid when producing the acid-coated slag. In some examples, the oxidizer may be combined with the acid-coated slag during the reaction process. In one or more examples, the oxidizer may be or contain one or more hypochlorites (sodium hypochlorite), one or more peroxides (e.g., hydrogen peroxide), or a combination thereof. The oxidizer may have a concentration in a range from about 0.1 wt % to about 5 wt %, relative to weight of the metal slag.

At operation 130, in one or more embodiments, the acid-coated slag is maintained at an ambient temperature (e.g., about 15° C. to about 25° C.) and ambient pressure (about 0.9 atm to about 1.1 atm) during the reaction process. The acid-coated slag may generate heat due to the ongoing exothermic reactions between the one or more acids and the one or more metals, as well as other reactions. However, in one or more examples, additional heat or thermal energy is not transferred to the acid-coated slag from external heating or thermal sources (e.g., electric heater, fire-driven heater, heater fluid, heat exchanger, UV-heater, or other thermal sources) during the reaction process. In one or more examples, the acid-coated slag is contained on a pad, a platform, a base, or in a container during the reaction process. Exemplary pads may be or include a storage pad, a leaching pad, or other types of pads. In other examples, the acid-coated slag may be contained in a mixer or a mixing apparatus, such as used at operation 120, during the reaction process.

In one or more embodiments, the acid-coated slag is maintained at a temperature in a range from about 0° C., about 5° C., about 10° C., about 15° C., about 18° C., or about 20° C. to about 22° C., about 25° C., about 28° C., about 30° C., about 35° C., about 40° C., about 45° C., about 50° C., or greater during the reaction process. For example, the acid-coated slag is maintained at a temperature in a range from about 0° C. to about 50° C., about 5° C. to about 40° C., about 5° C. to about 35° C., about 5° C. to about 30° C., about 5° C. to about 28° C., about 5° C. to about 25° C., about 5° C. to about 22° C., about 5° C. to about 20° C., about 5° C. to about 18° C., about 5° C. to about 15° C., about 5° C. to about 10° C., about 10° C. to about 40° C., about 10° C. to about 35° C., about 10° C. to about 30° C., about 10° C. to about 28° C., about 10° C. to about 25° C., about 10° C. to about 22° C., about 10° C. to about 20° C., about 10° C. to about 18° C., about 10° C. to about 15° C., about 10° C. to about 12° C., about 15° C. to about 40° C., about 15° C. to about 35° C., about 15° C. to about 30° C., about 15° C. to about 28° C., about 15° C. to about 25° C., about 15° C. to about 22° C., about 15° C. to about 20° C., about 15° C. to about 18° C., about 20° C. to about 40° C., about 20° C. to about 35° C., about 20° C. to about 30° C., about 20° C. to about 28° C., about 20° C. to about 25° C., or about 20° C. to about 22° C. during the reaction process.

In some embodiments, the acid-coated slag may be maintained at a pressure in a range from about 0.9 atm, about 0.92 atm, about 0.94 atm, about 0.95 atm, about 0.96 atm, about 0.97 atm, about 0.98 atm, or about 0.99 atm to about 1 atm, about 1.01 atm, about 1.02 atm, about 1.03 atm, about 1.04 atm, about 1.05 atm, about 1.06 atm, about 1.08 atm, about 1.1 atm, or greater during the reaction process. For example, the acid-coated slag may be maintained at a pressure in a range from about 0.9 atm to about 1.1 atm, about 0.95 atm to about 1.05 atm, about 0.96 atm to about 1.04 atm, about 0.98 atm to about 1.02 atm, or about 0.99 atm to about 1.01 atm during the reaction process.

In some embodiments, the acid-coated slag may be maintained reacting for a reaction time within a range from about 1 day (or about 24 hours), at least 1 day (or at least 24 hours), about 1.2 days, about 1.5 days, about 1.8 days, about 2 days, about 3 days, about 4 days, about 5 days, about 6 days, about 7 days, about 8 days, about 9 days, or about 10 days to about 12 days, about 15 days, about 18 days, about 20 days, about 25 days, about 30 days, about 35 days, about 40 days, about 50 days, about 60 days, about 70 days, about 80 days, about 90 days, about 100 days, about 120 days, about 135 days, about 150 days, or longer during the reaction process. For example, the reaction time may be in a range from about 1 day to about 150 days, about 1 day to about 120 days, about 2 days to about 100 days, about 2 days to about 80 days, about 2 days to about 60 days, about 2 days to about 50 days, about 2 days to about 40 days, about 2 days to about 30 days, about 2 days to about 25 days, about 2 days to about 20 days, about 2 days to about 18 days, about 2 days to about 15 days, about 2 days to about 12 days, about 2 days to about 10 days, about 2 days to about 8 days, about 2 days to about 5 days, about 2 days to about 4 days, about 5 days to about 100 days, about 5 days to about 80 days, about 5 days to about 60 days, about 5 days to about 50 days, about 5 days to about 40 days, about 5 days to about 30 days, about 5 days to about 25 days, about 5 days to about 20 days, about 5 days to about 18 days, about 5 days to about 15 days, about 5 days to about 12 days, about 5 days to about 10 days, about 5 days to about 8 days, about 10 days to about 100 days, about 10 days to about 80 days, about 10 days to about 60 days, about 10 days to about 50 days, about 10 days to about 40 days, about 10 days to about 30 days, about 10 days to about 25 days, about 10 days to about 20 days, about 10 days to about 18 days, about 10 days to about 15 days, about 10 days to about 12 days, about 15 days to about 100 days, about 15 days to about 80 days, about 15 days to about 60 days, about 15 days to about 50 days, about 15 days to about 40 days, about 15 days to about 30 days, about 15 days to about 25 days, about 15 days to about 20 days, about 15 days to about 18 days, about 3 days to about 30 days, about 4 days to about 20 days, about 5 days to about 15 days, about 8 days to about 12 days, or about 8 days to about 10 days during the reaction process.

At operation 140, after the reaction process, a separation process is provided and includes separating the generated or produced metal salts containing the valuable metals from the residual slag. Water is added to the remaining products and unreacted materials of the reaction process. The remaining materials may contain acid-coated slag (e.g., unreacted acid and metal slag), metal salts produced metal salts containing the valuable metals and the residual slag. The metal salts are dissolved in the added water to produce an aqueous metal salt solution, which is separated from the residual slag. The separation process may be or include one or more of a washing process, a decantation process, a filtration process, a centrifugal process, one or more other processes, or any combination thereof. In some embodiments, the separation process may include one, two, three, or more sequential steps or processes.

The aqueous metal salt solution contains the metal salts. Exemplary metal salts may be or contain one or more salts or one or more compounds of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof. Exemplary metal salts may be or contain vanadium pentoxide, manganese sulfate, iron sulfate, copper sulfate, lithium sulfate, lithium chloride, zinc sulfate, antimony sulfate, lead sulfate, titanium oxide, iron oxide, magnesium oxide, lithium oxide, lithium compounds, arsenic compounds or salts, or any combination thereof.

The water and the metal salts are combined to produce the aqueous metal salt solution. In one or more embodiments, the water may be combined and/or mixed at an amount in a range from about 2 times, about 3 times, about 4 times, about 5 times, about 6 times, about 7 times, about 8 times, about 9 times, about 10 times, about 12 times, about 13 times, about 14 times, about 14.5 times, about 15 times, about 15.5 times, about 16 times, about 16.5 times, about 17 times, about 17.5 times, about 18 times, about 19 times, about 20 times, about 25 times, or more in weight relative to the weight of the metal slag. For example, the water may be combined and/or mixed at an amount in a range from about 2 times to about 20 times, about 2 times to about 18 times, about 2 times to about 17 times, about 2 times to about 16 times, about 2 times to about 15 times, about 2 times to about 14 times, about 2 times to about 12 times, about 2 times to about 10 times, about 2 times to about 8 times, about 2 times to about 6 times, about 2 times to about 5 times, about 2 times to about 4 times, about 4 times to about 20 times, about 4 times to about 18 times, about 4 times to about 17 times, about 4 times to about 16 times, about 4 times to about 15 times, about 4 times to about 14 times, about 4 times to about 12 times, about 4 times to about 10 times, about 4 times to about 8 times, about 4 times to about 6 times, about 6 times to about 20 times, about 6 times to about 18 times, about 6 times to about 17 times, about 6 times to about 16 times, about 6 times to about 15 times, about 6 times to about 14 times, about 6 times to about 12 times, about 6 times to about 10 times, about 6 times to about 8 times, about 10 times to about 20 times, about 10 times to about 18 times, about 10 times to about 17 times, about 10 times to about 16 times, about 10 times to about 15 times, about 10 times to about 14 times, about 10 times to about 12 times, about 3 times to about 10 times, about 5 times to about 7 times, about 14 times to about 20 times, about 14 times to about 19 times, about 14 times to about 18 times, about 14 times to about 17.5 times, about 14 times to about 17 times, about 14 times to about 16.5 times, about 14 times to about 16 times, or about 14 times to about 15 times, in weight relative to the weight of the metal slag.

In some embodiments, once the aqueous metal salt solution and the residual slag are separated, the aqueous metal salt solution may be further purified and/or the residual slag may be recycled or otherwise introduced upstream into mixing process (at operation 120). In one or more embodiments, the aqueous metal salt solution may be exposed to a fine filtration process after the separation process. The fine filtration process removes solid particulate from the aqueous metal salt solution. In some examples, the solid particulate may be or contain silica, calcium sulfate, other salts, or any combination thereof.

In other embodiments, the aqueous metal salt solution may be exposed to a purification process to separate the metal salts from the water. In one or more examples, the purification process is conducted after the fine filtration process. In some examples, the fine filtration process is omitted and the aqueous metal salt solution is exposed to the purification process. In other examples, the fine filtration process is conducted before the purification process. The purification process may be or include a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof.

In one or more embodiments, a raffinate may be produced from the purification process. In some examples, at least a portion of the raffinate may be transferred, recycled, or otherwise introduced into an upstream process, to the metal slag, to the acid-coated slag, and/or any combination thereof. In some embodiments, at least a portion of the water of the aqueous metal salt solution may be separated from the aqueous metal salt solution and transferred, recycled, or otherwise introduced into an upstream process, to the acid-coated slag, back to the metal salts to produce additional aqueous metal salt solution, and/or any combination thereof. In other embodiments, at least a portion of the acid may be separated from the acid-coated slag and transferred, recycled, or otherwise introduced into an upstream process, to the metal slag to produce additional acid-coated slag, or any combination thereof.

In one or more embodiments, a relatively high percentage for each of the metals is independently recovered or separated from the metal slag, the metal ore, the black mass, and/or other metal source. Each metal (e.g., element), including, but not limited to, iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, nickel, and tin, is independently recovered or separated at a relatively high percentage from the metal slag, the metal ore, the black mass, and/or other metal source. Each of the metals of the metal salts is independently recovered from the metal slag at a percentage in a range from about 70 wt % or greater, about 75 wt % or greater, about 80 wt % or greater, about 85 wt % or greater, about 90 wt % or greater, about 92 wt % or greater, about 95 wt % or greater, or about 98 wt % or greater, relative to an original amount of the metal in the metal slag or other metal source.

In one or more embodiments, each of the metals or elements is independently recovered from the metal slag at a percentage in a range from about 70 wt %, about 72 wt %, about 75 wt %, about 78 wt %, about 80 wt %, about 82 wt %, about 84 wt %, or about 85 wt % to about 86 wt %, about 88 wt %, about 90 wt %, about 92 wt %, about 93 wt %, about 94 wt %, about 95 wt %, about 96 wt %, about 97 wt %, about 98 wt %, about 99 wt %, or about 100 wt %, relative to an original amount of the metal in the metal slag or other metal source. For example, each of the metals or elements is independently recovered from the metal slag at a percentage in a range from about 70 wt % to about 100 wt %, about 70 wt % to about 99 wt %, about 70 wt % to about 98 wt %, about 70 wt % to about 95 wt %, about 70 wt % to about 92 wt %, about 70 wt % to about 90 wt %, about 70 wt % to about 88 wt %, about 70 wt % to about 85 wt %, about 70 wt % to about 82 wt %, about 70 wt % to about 80 wt %, about 70 wt % to about 78 wt %, about 70 wt % to about 75 wt %, about 70 wt % to about 72 wt %, about 80 wt % to about 100 wt %, about 80 wt % to about 99 wt %, about 80 wt % to about 98 wt %, about 80 wt % to about 95 wt %, about 80 wt % to about 92 wt %, about 80 wt % to about 90 wt %, about 80 wt % to about 88 wt %, about 80 wt % to about 85 wt %, about 80 wt % to about 82 wt %, about 90 wt % to about 100 wt %, about 90 wt % to about 99 wt %, about 90 wt % to about 98 wt %, about 90 wt % to about 95 wt %, or about 90 wt % to about 92 wt %, relative to an original amount of the metal in the metal slag or other metal source.

In another embodiment, the method 100 includes an extraction cycle which may be conducted or repeated 1 time, 2 times, 3 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, 10 times, or more times. Any, all, or portions of operations 110, 120, 130, and/or 140 may be repeated in a cyclic fashion to further process the metal stag, the residual slag, or mixtures thereof. In one or more embodiments, the extraction cycle may include reintroducing the residual slag upstream, such as at operation 110, and exposing the residual slag to the acid. The residual metal slag may contain one or more valuable metals, such as iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof. The extraction cycle may further include mixing the residual slag and the acid to produce an acid-coated residual slag, reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process. The extraction cycle may further include providing the acid-coated residual slag an additional reaction time of about 24 hours or longer and separating the additional metal salts and the secondary residual slag during a second separation process. The additional metal salts may contain one or more valuable metals, such as iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

FIG. 2 is a flowchart depicting a method 200 for removing metals from metal slags, according to one or more embodiments described and discussed herein. In one of more embodiments, the method 200 is an exemplary process or method of the method 100. In other embodiments, the method 200 includes different processes or methods of the method 100. The method 200 may be conducted or otherwise used to extract, recover, remove, or otherwise separate valuable metals from various metal sources which may be or contain one or more metal slags, one or more ores, one or more black masses, other metal containing waste sources, and/or other materials. In one or more embodiments, one or more other metal sources (e.g., black mass, ores, other metal-containing waste or material) may be similarly treated with or without the metal slag by the method 200.

In some embodiments, the method 200 may include exposing a metal slag to a size reduction process at operation 202. The metal slag may be reduced to a particle size of P80 0.25 inch or less during the size reduction process. For example, the size reduction process used to reduce the particle size of the metal source or metal slag may be or include one or more of techniques, such as milling, grinding, smashing, crushing, or any combination thereof. In some examples, the metal source or metal slag is reduced to a particle size of about P80 0.25 inch or less during the size reduction process.

In one or more embodiments, the metal slag may at or may be reduced to a size in a range from about or less than 1 mm (mesh #18), about or less than 1.19 mm (mesh #16), about or less than 1.41 mm (mesh #14), about or less than 1.5 mm, about or less than 1.6 mm, about or less than 1.68 mm (mesh #12), about or less than 1.8 mm, or about or less than 2 mm (mesh #10) to about or less than 2.2 mm, about or less than 2.38 mm (mesh #8), about or less than 2.4 mm, about or less than 2.5 mm, about or less than 2.6 mm, about or less than 2.8 mm, about or less than 2.83 mm (mesh #7), about or less than 3 mm, about or less than 3.2 mm, about or less than 3.36 mm (mesh #6), about or less than 3.4 mm, about or less than 3.5 mm, about or less than 3.6 mm, about or less than 3.8 mm, about or less than 4 mm (mesh #5), about or less than 4.2 mm, about or less than 4.4 mm, about or less than 4.5 mm, about or less than 4.6 mm, about or less than 4.76 mm (mesh #4), about or less than 4.8 mm, about or less than 5 mm, or greater. For example, the metal slag may at or may be reduced to a size in a range from about 1 mm to about 5 mm, about 1 mm to about 4.5 mm, about 1 mm to about 4.2 mm, about 1 mm to about 4 mm, about 1 mm to about 3.8 mm, about 1 mm to about 3.5 mm, about 1 mm to about 3.2 mm, about 1 mm to about 3 mm, about 1 mm to about 2.8 mm, about 1 mm to about 2.5 mm, about 1 mm to about 2.2 mm, about 1 mm to about 2 mm, about 1 mm to about 1.8 mm, about 1 mm to about 1.5 mm, about 1 mm to about 1.2 mm, about 2 mm to about 5 mm, about 2 mm to about 4.5 mm, about 2 mm to about 4.2 mm, about 2 mm to about 4 mm, about 2 mm to about 3.8 mm, about 2 mm to about 3.5 mm, about 2 mm to about 3.2 mm, about 2 mm to about 3 mm, about 2 mm to about 2.8 mm, about 2 mm to about 2.5 mm, about 2 mm to about 2.2 mm, about 3 mm to about 5 mm, about 3 mm to about 4.5 mm, about 3 mm to about 4.2 mm, about 3 mm to about 4 mm, about 3 mm to about 3.8 mm, about 3 mm to about 3.5 mm, about 3 mm to about 3.2 mm, about 4 mm to about 5 mm, about 4 mm to about 4.5 mm, or about 4 mm to about 4.2 mm.

In one or more embodiments, the method 200 includes stockpiling the metal slag in a container or a pad at operation 204. In some examples, the metal slag may be size reduced at operation 202 and then the metal slag may be transferred and/or stored in the stockpile at operation 204. In other examples, the metal slag may be stored in the stockpile at operation 204 prior to exposing the metal slag to a size reduction process at operation 202.

At operation 210, the metal slag may be exposed to one or more acids, as described above for operation 110. In some examples, the metal slag and the acid may be pre-mixed at operation 210.

At operation 220, the metal slag and the acid may be mixed to produce an acid-coated slag, as described above for operation 120.

At operation 230, the metals in the metal slag react with the acid to produce metal salts and a residual slag during a reaction process, as described above for operation 130.

At operation 240, the metal salts and the residual slag may be separated during a separation process, as described above for operation 140. For example, the separation process of method 200 further includes dissolving the metal salts in water to produce an aqueous metal salt solution and separating the aqueous metal salt solution from the residual slag at operation 240, as described above for operation 140.

At operation 250, in one or more embodiments, the residual slag may be transferred into a storage container or area for disposal or further processing.

At operation 252, in other embodiments, the residual slag may be transferred, recycled, or otherwise introduced upstream, such as into the metal slag and the acid at one or more operations 202, 204, 210, and/or 220 (illustrated going to operation 210).

At operation 260, the aqueous metal salt solution may be exposed to a fine filtration process after the separation process. Solid particulates may be removed from the aqueous metal salt solution during the fine filtration process. The solid particulate may be or contain silica, calcium sulfate, one or more other solids, powders, and/or salts, or any combination thereof, as described above for operation 140.

At operation 262, in one or more embodiments, the solid particulate may be transferred into a storage container or area for disposal or further processing.

At operation 270, the aqueous metal salt solution may be exposed to a purification process to separate the metal salts from the water, as described above for operation 140. In some examples, the purification process may be or include one or more of a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof. In one or more embodiments, a raffinate may be produced from the purification process at operation 270. The raffinate may be produced from the purification process and is a liquid residual product resulting from the extraction of the metal salt from the aqueous metal salt solution. In one or more examples, the aqueous metal salt solution may be or contain iron, vanadium, zinc, antimony, copper, lithium, arsenic, ions thereof, compounds thereof, salts thereof, or any combination thereof.

At operation 272, in one or more embodiments, recovered metal salts may be transferred into a storage container, a pad, or an area. In one or more examples, the metal salts may be or contain vanadium oxide, iron oxide, iron sulfate, other metal oxides and/or sulfates, or any combination thereof.

At operation 274, in one or more embodiments, at least a portion of the raffinate may be transferred, recycled, or otherwise introduced into any upstream process, such as into the separation process at operation 240.

At operation 276, in one or more embodiments, at least a portion of the raffinate may be transferred, recycled, or otherwise introduced into any upstream process, such as into another purification process at operation 280. In some examples, the purification process at operation 280 may be or include one or more of a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof. At operation 280, a second raffinate may be produced from the purification process at operation 270.

At operation 282, in one or more embodiments, at least a portion of the second raffinate may be transferred, recycled, or otherwise introduced into any upstream process, such as into the separation process at operation 240.

In other embodiments, at least a portion of (or all of) the first and/or second raffinate may be transferred, recycled, or otherwise introduced into an upstream process, to the metal slag, to the acid-coated slag, and/or any combination thereof.

In one or more embodiments, the methods 100 and/or 200 include exposing the metal slag to one or more acids, where the metal slag may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof, and mixing at least the metal slag and the acid to produce an acid-coated slag. In some embodiments, the methods 100 and/or 200 include mixing one or more coordinating agents, one or more oxidizer, a combination thereof along with the metal slag to one or more acids to produce an acid-coated slag. The method 100 and/or 200 may also include reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which includes providing the acid-coated slag a reaction time of about 24 hours or longer. The method 100 and/or 200 may also include separating the metal salts and the residual slag during a separation process. The metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof. The method 100 and/or 200 may further include repeating an extraction cycle, for example, recycling the residual slag at operation 252.

The extraction cycle may include exposing the residual slag to one or more acids, where the residual metal slag still contain valuable metals, such as one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof. The method 100 and/or 200 may also include mixing the residual slag and the acid to produce an acid-coated residual slag and reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process which includes providing the acid-coated residual slag an additional reaction time of about 24 hours or longer. The method 100 and/or 200 may also include separating the additional metal salts and the secondary residual slag during a second separation process. The additional metal salts may contain one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof. In one or more examples, the extraction cycle is conducted or repeated one time, two times, three times, four times, five times, or more.

In one or more embodiments, the steel slag, generated as a byproduct of steelmaking, may be first collected and subjected to size reduction to enhance reaction kinetics. The slag may be milled or crushed to achieve a target particle size, typically with a P80 of ¼ inch or finer. This ensures a larger surface area for the subsequent reactions.

In one or more examples, the pre-treated slag may be mixed with a measured amount of sulfuric acid (H₂SO₄). In other examples, one or more other acids may be exposed to the slag. Water may be added to adjust the moisture content of the mixture to reach optimal humidity (water content or concentration in a range from about 0 wt % to about 10 wt %, for example, about 0.1 wt % to about 3 wt %). The method may include an application of the acid and water followed by mixing in a pulse-mixing reactor. The acid with a relatively small concentration of water when mixed with the slag essentially forms a paste. The mixture is agitated to ensure coverage of the slag surfaces, so to promote the reaction between the acid and metals in the slag.

These separate pre-mixing and mixing steps could be combined into a single mix step. In one or more examples, the mixing may be performed at ambient temperature and atmospheric pressure, allowing the acid to react with the surface of the slag particles, forming a uniform coating, but in other examples, heating may be applied to increase reaction kinetics. This controlled addition of water aids in further dispersing the acid evenly over the slag particles.

In one or more embodiments, a pulse mixing reactor, as depicted in FIG. 3, may be used to spray or otherwise introduce acid and water from pipes onto rotating helix mixer blades while combining the metal slag with the acid to produce the acid-coated slag, according to one or more embodiments described and discussed herein.

SUMMARY EMBODIMENTS

In one or more embodiments, the acid-treated slag is allowed to react at ambient temperature under atmospheric pressure for a period ranging from 1 day to about 150 days, such as about 10 days to about 20 days. This may be done in the one or more embodiments as a heap on a pad. During this period, the acid gradually reacts with the metals present in the slag, such as vanadium, manganese, and iron, forming water-soluble salts. The reaction results in water soluble metal salts such as Fe₂(SO₄). Indicators such as changes in the color of the mixture can be used to monitor the progress of this reaction. Typically, water evaporates during this reaction stage. Acid could be intermittently or continuously applied to the heap.

In some embodiments, once the reaction period is complete, the dried mixture is washed with water to dissolve the water-soluble metal salts. The washing is performed in a stirred vessel to ensure thorough dissolution or can be done via irrigation of a heap. This step uses significantly less water compared to traditional leaching methods, maintaining a water-to-slag ratio that optimizes the dissolution of the metal salts while minimizing waste.

In one or more embodiments, the metal-laden solution is further treated using standard purification methods like solvent extraction, precipitation, or ion exchange. These methods allow for the selective recovery of vanadium and other metals such as manganese and titanium, based on their specific chemical properties. The choice of purification method depends on the desired product purity and economic considerations.

In other embodiments, water and residual acid from the washing and separation stages can be recycled into subsequent batches to improve process efficiency and reduce environmental impact. This recycling minimizes the overall consumption of fresh acid and water, making the process more sustainable and cost-effective.

In one or more embodiments, the methods described and discussed here eliminate the need for high-temperature calcination, significantly reducing energy consumption.

In some embodiments, the controlled application of acid directly onto the slag particles results in reduced acid usage, in some examples, about 100 g to about 150 g of acid per 1 kg of the metal slag. In other examples, the controlled application of acid directly onto the slag particles may be about 500 g to about 700 g of acid per 1 kg of the metal slag.

In one or more embodiments, all of the reaction processes or steps may occur at ambient temperature (e.g., about 5° C. to about 30° C., or about 18° C. to about 25° C.), eliminating the need for external heating, which simplifies the equipment required and lowers operational costs.

In other embodiments, the methods described and discussed herein may use less than 6 liters of water per kilogram of slag for washing.

In some embodiments, the methods described and discussed herein may be used for various types of steel slags and other metal slags with different compositions, allowing flexibility in processing mixed slags and optimizing recovery for a range of metals.

This innovative methods described and discussed herein allow for the efficient recovery of valuable metals from metal slags (e.g., steel slag), metal ores, and/or other metal sources while reducing environmental impact and operational complexity. The methods described and discussed herein represent a significant advancement in the field of slag processing and metal recovery.

EXAMPLES

In order to provide a better understanding of the foregoing discussion, the following non-limiting examples are offered. Although the examples and/or experiments can be directed to specific examples, they are not to be viewed as limiting the invention in any specific respect.

Experiment 1: Vanadium rich slag from a steelmaker BOF in Chile was used for Experiment 1. A slag sample was crushed to P80-¼″. The slag was sampled and tested for various minerals using induced coupled plasma (ICP) in the lab. A 1 kg sample of the slag was added along with 75 kg/t (kilogram per ton) sulfuric acid in a rotating tubular mixer. Water was also added to reach 3% humidity. The contents were mixed until the slag was coated with a uniform sulfuric acid paste. The acid coated slag was removed from the mixer and allowed to sit at ambient conditions for 10 days. During this time, the water evaporated, but the acid reacted with many of the metals forming water soluble salts.

After reacting for 10 days, the solids were mixed with 1 L of water dissolving the water-soluble metal salts. The recovered solution was a dark brown solution. The remaining residual solids were dried and testing with ICP.

The recovery values of the metals of interest in the washed solution are shown below in Table 1. Fe, Mg, Ti, Mn, V, Cr, and Co were all recovered with recoveries greater than 70%. This was done with less water and less acid than the standard acid leach process. No calcination or pretreatment other than milling was done on the slag.

TABLE 1
Experiment 1 results showing yields
between 71%-92% for various metals.

			Mass in
	Mass in		residual
	slag		solids		Recovered

	Mass Fe	154.0	g	29.6	g	81%
	Mass Mg	39.9	g	3.1	g	92%
	Mass Ti	5.2	g	1.4	g	72%
	Mass Mn	15.0	g	1.5	g	90%
	Mass V	12.7	g	3.7	g	71%
	Mass Cr	3.1	g	0.7	g	77%
	Mass Co	0.010	g	0.003	g	75%

Experiment 2: Vanadium rich slag from a steelmaker BOF in Chile was used for Experiment 2. In order to increase yields, especially for vanadium, a similar experiment was performed with multiple mixing, steps. Slag was milled to the size of P80 ¼″. A 1.75 kg sample was added into the mixer along with 75 kg/t sulfuric acid and water added to adjust the humidity to 2%. The mixture formed a paste and was mixed long enough to for a homogenous coating of the slag particles, similar to Experiment 1. This mixture was then removed from the mixture and allowed to react at ambient conditions for 10 days. After 10 days, the water-soluble salts were washed twice with 1.5 L of water for a total of 3 L.

The residual solids were again added to the mixer with 65 kg/t sulfuric acid and water added for 2% humidity. The slag particles again were coated uniformly with the acid paste. The mixture was removed and allowed to again react for 10 additional days after which the same wash procedure was followed.

The process was repeated a 3rd time with slightly less acid (40 kg/t) and mixed and reacted as above. The humidity was adjusted again to 2%. The mixture was coated uniformly then removed and reacted for 10 days at ambient conditions. Subsequently, the mixture was washed with the same wash procedure.

Vanadium was tested via ICP in the starting slag and the residual solids after 3 reaction steps. About 99.9% of the vanadium was leached from the starting slag.

Experiment 3: Black Mass—In the recycling of electronic waste, particularly spent lithium-ion batteries, the term black mass refers to the fine dark powder obtained after the mechanical processing of used cells. Once the batteries are discharged and shredded, the casings, current collectors, and plastics are separated, leaving behind a heterogeneous mixture composed primarily of the electrode materials. This fraction, known as black mass, contains the most valuable critical elements, including lithium, copper, cobalt, nickel, manganese, or any combination thereof, as well as graphite originating from the anode. Minor amounts of binders such as polyvinylidene fluoride (PVDF) and residual electrolyte salts, often lithium hexafluorophosphate (LiPF₆), can also be present, making the material chemically complex and potentially hazardous. The exact composition of black mass varies according to battery chemistry. In one or more examples, the black mass is derived from nickel-manganese-cobalt (NMC) cathodes and may contain cobalt in the range of about 5 wt % to about 30 wt %, nickel in the range of about 5 wt % to about 20%, lithium in the range of about 2 wt % to about 7 wt %, manganese in the range of about 5 wt % to about 15%, and graphite in the range of about 15 wt % to about 40 wt % of the material. This high concentration of critical metals makes this black mass the key intermediate in lithium-ion battery recycling.

The black mass samples were provided by Kopper Chemical Industry Corp, located in Chongqing, China. These samples have a composition of about 3.17 wt % of Li, about 19.5 wt % of Ni, about 6.0 wt % of Co, about 2.5 wt % of Mn, about 4.4 wt % of Cu, and about 1.6 wt % of Al. The results of the experiment performed, which evaluated the effect of the acid amount in the extraction of the different black mass metals, are provided in the graph illustrated in FIG. 4.

The recovery of metals from black mass increased with the amount of sulfuric acid employed during the process. However, when high acid dosages were used, ranging from about 600 g of acid per kg of black mass to about 1,000 g of acid per kg of black mass, the extraction behavior of Cu, Co, Mn, and Ni differs. Copper reached a maximum recovery at about 600 g of acid per kg of black mass, and this value remains essentially constant up to 800 g of acid per kg of black mass. Under the same conditions, increasing the acid dosage from about 600 g of acid per kg of black mass to about 800 g of acid per kg of black mass resulted in higher recoveries of Co and Ni, while Mn recovery decreased. When the acid dosage is further increased from about 800 g of acid per kg of black mass to about 1,000 g of acid per kg of black mass, Cu recovery decreased, whereas the recoveries of Co, Mn, and Ni increased. These various recoveries can be attributed to the different solubility and stability of the metal sulfates formed during the extraction, as well as to more complex interactions among the sulfates themselves and with residues from the polymeric matrix in which the metals are embedded.

Experiment 4: Coordinating agent and varied amounts of acid—Experiment 4 includes 10 recovery processes, each with an increasing amount of sulfuric acid, along with a coordinating agent (NaCl) in Cu—Zn slag samples from Baiyin slag of Chongqing, China, which results are shown in FIG. 5. The 10 recovery processes included 60 g, 80 g, 100 g, 120 g, 160 g, 200 g, 240 g, 300 g, 400 g, and 600 g of sulfuric acid, respectively, each combined with 1 kg of Cu—Zn slag and 25 g of sodium chloride. The graph of FIG. 5 illustrates an increase in the recovery of the desired metals (e.g., Cu, Zn, Al, Fe) from the Cu—Zn slag relative to a greater amount of sulfuric acid applied to the slag.

For the example using 600 g of sulfuric acid, the weight percentage of recovered metals were found to be about 33% for Cu, about 37% for Zn, about 53% for Al, and about 34% for Fe. The recovery tendency across the 10 different amounts of sulfuric acid shows a linear increment in Cu, Zn, and Fe recovery and a non-linear increment in the recovery of Al, possibly due to a different disposition or availability of Al in the slag structure.

Adding 25 g of NaCl as complexing agent shows an increase in the extraction for all metals, as observed in FIG. 9. A notorious increase of 5 points in Cu recovery, from 13% to 18% is achieved due to the formation of inner coordination complex between Cu²⁺ cations and Cl⁻ anions given by the NaCl. An increase of 2 to 3 points in the other metals is observed as well.

Experiments 5A-5B: Coordinating Agent Comparison—Experiments 5A and 5B are conducted to compare the effectiveness of a coordinating agent (NaCl) used in the recovery of select metals from a Cu—Zn slag sample from Baiyin slag of Chongqing, China, which results are shown in Table 2. Experiment 5A is a comparative example of a process which recovers the desired metals from the slag without using an added coordinating agent. Experiment 5B is an example of the same process and conditions, but while using an added coordinating agent.

In Experiment 5A, about 200 g of sulfuric acid was combined with 1 kg of Cu—Zn slag without any added sodium chloride. In Experiment 5B, about 200 g of sulfuric acid was combined with 1 kg of Cu—Zn slag and 25 g of sodium chloride. Both Experiments 5A and 5B were conducted and worked-up with the same conditions and procedures.

TABLE 2
Table 2 - Shows yields of select metals in Experiment 5A (without
coordinating agent) and Experiment 5B (with coordinating agent).

	Experiment 5A: Recovered	Experiment 5B: Recovered
Metal	Metal Amount (wt %)	Metal Amount (wt %)

Cu	13	18
Zn	14	17
Al	18	21
Fe	11	13

As noted in Table 2, more of the desired metals were recovered in Experiment 5B utilizing the coordinating agent than in Experiment 5A which was free of the added coordinating agent. The respective weight percentages of recovered metals were found to be as follows: copper was increased from about 13 wt % to about 18 wt %, zinc was increased from about 14 wt % to about 17 wt %, aluminum was increased from about 18 wt % to about 21 wt %, and iron was increased from about 11 wt % to about 13 wt %.

The present disclosure provides, among others, the following embodiments, each of which may be considered as optionally including any alternate embodiments per one or more of the following Clauses 1-65:

Clause 1. A method of removing metals from a slag, comprising: exposing a metal slag to an acid, wherein the metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; and separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

Clause 2. A method of removing metals from a slag, comprising: exposing a metal slag to a size reduction process, wherein the metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, and wherein the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process; exposing the metal slag to an acid; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, wherein the separation process further comprises: dissolving the metal salts in water to produce an aqueous metal salt solution; and separating the aqueous metal salt solution from the residual slag; then exposing the aqueous metal salt solution to a fine filtration process after the separation process, wherein solid particulate is removed from the aqueous metal salt solution, and wherein the solid particulate comprises silica, calcium sulfate, or any combination thereof; and then exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water, wherein the purification process comprises a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof.

Clause 3. A method of removing metals from a slag, comprising: exposing a metal slag to an acid, wherein the metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; and repeating an extraction cycle, comprising: exposing the residual slag to the acid, wherein the residual metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing the residual slag and the acid to produce an acid-coated residual slag; reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process comprising providing the acid-coated residual slag an additional reaction time of at least 24 hours; and separating the additional metal salts and the secondary residual slag during a second separation process, wherein the additional metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

Clause 4. The method according to Clause 3, wherein the extraction cycle is conducted or repeated 1 time to 5 times.

Clause 5. The method according to any one of Clauses 1-4, wherein prior to exposing the metal slag to the acid, further comprising exposing the metal slag to a size reduction process.

Clause 6. The method according to any one of Clauses 1-5, wherein the size reduction process comprises milling, grinding, smashing, crushing, or combinations thereof the metal slag.

Clause 7. The method according to any one of Clauses 1-6, wherein the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process.

Clause 8. The method according to any one of Clauses 1-7, wherein the metal slag further comprises titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

Clause 9. The method according to any one of Clauses 1-8, wherein the metal salts comprise one or more of titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

Clause 10. The method according to any one of Clauses 1-9, wherein the metal slag comprises one or more of steel slag, zinc slag, copper slag, lead slag, a zinc and lead slag, tin slag, antimony slag, nickel slag, tungsten ore, arsenic ore, or any combination thereof.

Clause 11. The method according to any one of Clauses 1-10, wherein each of the metals of the metal salts is independently recovered from the metal slag at about 70 wt % or greater, about 75 wt % or greater, about 80 wt % or greater, about 85 wt % or greater, about 90 wt % or greater, or about 95 wt % or greater, relative to an original amount of the metal in the metal slag or other metal source.

Clause 12. The method according to any one of Clauses 1-11, wherein the acid comprises sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, citric acid, or any combination thereof.

Clause 13. The method according to any one of Clauses 1-12, wherein the acid comprises sulfuric acid, and the acid is mixed with the metal slag to produce the acid-coated slag at an amount or concentration in a range from about 2.5 wt % to about 50 wt %, about 5 wt % to about 30 wt %, about 7.5 wt % to about 25 wt %, or about 10 wt % to about 15 wt % relative to the weight of the metal slag.

Clause 14. The method according to any one of Clauses 1-13, wherein the acid comprises sulfuric acid having a concentration of greater than 90 wt %, such as about 95 wt % or greater, about 96 wt % or greater, about 97 wt % or greater, or about 98 wt % or greater.

Clause 15. The method according to any one of Clauses 1-14, wherein exposing the metal slag to the acid comprises spraying or pouring the acid onto the metal slag.

Clause 16. The method according to any one of Clauses 1-15, wherein mixing the metal slag and the acid comprises rotating or tumbling the metal slag and the acid to produce the acid-coated slag.

Clause 17. The method according to any one of Clauses 1-16, wherein the metal slag and the acid are mixed in or by a rotating mixer, a cylinder mixer, a drum mixer, a helix mixer, a tumbler, rotating blades, an oscillator, a pulse-mixing reactor, or any combination thereof.

Clause 18. The method according to any one of Clauses 1-17, wherein the acid-coated slag is maintained at an ambient temperature and ambient pressure during the reaction process.

Clause 19. The method according to any one of Clauses 1-18, wherein the acid-coated slag is maintained at a temperature in a range from about 5° C. to about 40° C., about 10° C. to about 35° C., about 15° C. to about 30° C., or about 20° C. to about 25° C. during the reaction process.

Clause 20. The method according to any one of Clauses 1-19, wherein the acid-coated slag is maintained at a pressure in a range from about 0.9 atm to about 1.1 atm, about 0.95 atm to about 1.05 atm, about 0.96 atm to about 1.04 atm, about 0.98 atm to about 1.02 atm, or about 0.99 atm to about 1.01 atm during the reaction process.

Clause 21. The method according to any one of Clauses 1-20, wherein the reaction time is in a range from about 1 day to about 150 days, about 1 day to about 120 days, about 2 days to about 60 days, about 3 days to about 30 days, about 4 days to about 20 days, about 5 days to about 15 days, about 8 days to about 12 days, about 8 days to about 10 days, or about 10 days to about 12 days.

Clause 22. The method according to any one of Clauses 1-21, further comprising maintaining a water concentration of the acid-coated slag in a range from about 0.5 wt % to about 10 wt %, about 1 wt % to about 10 wt %, about 1 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 2 wt % to about 3 wt %, or about 3 wt % to about 4 wt % during the reaction process, wherein the water concentration is relative to the weight of the metal slag.

Clause 23. The method according to any one of Clauses 1-22, wherein the acid-coated slag is contained on a pad, a platform, a base, or in a container during the reaction process.

Clause 24. The method according to any one of Clauses 1-23, wherein the acid-coated slag is contained in a mixer or a mixing apparatus during the reaction process.

Clause 25. The method according to any one of Clauses 1-24, further comprising combining water with the metal slag and the acid to produce the acid-coated slag.

Clause 26. The method according to any one of Clauses 1-25, wherein: the water is combined with the metal slag and/or the acid prior to producing the acid-coated slag; the water is combined with the metal slag and the acid when producing the acid-coated slag; and/or the water is combined with the acid-coated slag during the reaction process.

Clause 27. The method according to any one of Clauses 1-26, wherein the separation process comprises: dissolving the metal salts in water to produce an aqueous metal salt solution; and separating the aqueous metal salt solution from the residual slag.

Clause 28. The method according to any one of Clauses 1-27, wherein the separation process comprises a filtration process, a washing process, a decantation process, a centrifugal process, or any combination thereof.

Clause 29. The method according to any one of Clauses 1-28, wherein the water and the metal salts are combined to produce the aqueous metal salt solution, and wherein the water is combined at an amount in a range from about 2 times to about 20 times, about 3 times to about 10 times, about 4 times to about 8 times, about 5 times to about 7 times, about 6 times to about 8 times, or about 4 times to about 6 times in weight relative to the weight of the metal slag.

Clause 30. The method according to any one of Clauses 1-29, wherein the aqueous metal salt solution is exposed to a fine filtration process after the separation process.

Clause 31. The method according to any one of Clauses 1-30, wherein the fine filtration process removes solid particulate from the aqueous metal salt solution.

Clause 32. The method according to any one of Clauses 1-31, wherein the solid particulate comprises silica, calcium sulfate, or any combination thereof.

Clause 33. The method according to any one of Clauses 1-32, further comprising exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water, wherein the purification process comprises a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof.

Clause 34. The method according to any one of Clauses 1-33, wherein the metal salts comprise one or more salts of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

Clause 35. The method according to any one of Clauses 1-34, wherein the metal salts comprise vanadium pentoxide, manganese sulfate, iron sulfate, copper sulfate, zinc sulfate, antimony sulfate, lead sulfate, titanium oxide, iron oxide, magnesium oxide, or any combination thereof.

Clause 36. The method according to any one of Clauses 1-35, wherein a raffinate is produced from the purification process, and wherein at least a portion of the raffinate is transferred, recycled, or otherwise introduced into an upstream process, to the metal slag, to the acid-coated slag, or any combination thereof.

Clause 37. The method according to any one of Clauses 1-36, wherein at least a portion of the water of the aqueous metal salt solution is separated from the aqueous metal salt solution and transferred, recycled, or otherwise introduced into an upstream process, to the acid-coated slag, back to the metal salts to produce additional aqueous metal salt solution, or any combination thereof.

Clause 38. The method according to any one of Clauses 1-37, wherein at least a portion of the acid is separated from the acid-coated slag and transferred, recycled, or otherwise introduced into an upstream process, to the metal slag to produce additional acid-coated slag, or any combination thereof.

Clause 39. The method according to any one of Clauses 1-38, wherein an extraction cycle is conducted or repeated 1 time to 5 times, and wherein the extraction cycle comprises: exposing the residual slag to the acid, wherein the residual metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing the residual slag and the acid to produce an acid-coated residual slag; reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process comprising providing the acid-coated residual slag an additional reaction time of at least 24 hours; and separating the additional metal salts and the secondary residual slag during a second separation process, wherein the additional metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

Clause 40. A method of removing metals from a slag, comprising: exposing a metal slag to an acid, wherein the metal slag comprises one or more metals selected from iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting the metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; and separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof, and wherein one or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt % or greater relative to an original amount of the metal in the metal slag.

Clause 41. A method of removing metals from a slag, comprising: exposing a metal slag to a size reduction process, wherein the metal slag comprises one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof, and wherein the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process; exposing the metal slag to an acid comprising sulfuric acid having a concentration of greater than 90 wt %; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof, wherein the separation process further comprises: dissolving the metal salts in water to produce an aqueous metal salt solution; and separating the aqueous metal salt solution from the residual slag; then exposing the aqueous metal salt solution to a fine filtration process after the separation process, wherein solid particulate is removed from the aqueous metal salt solution, and wherein the solid particulate comprises silica, calcium sulfate, or any combination thereof; and then exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water, wherein the purification process comprises a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof; and wherein one or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the metal in the metal slag.

Clause 42. A method of removing metals from a slag, comprising: exposing a metal slag to an acid, wherein the metal slag comprises one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof; mixing at least the metal slag and the acid to produce an acid-coated slag (optionally mixing one or more coordinating agents, one or more oxidizers, and/or any combination thereof to produce the acid-coated slag); reacting metals in the metal slag with the acid to produce metal salts and a residual slag during a reaction process which provides the acid-coated slag a reaction time of at least 24 hours; separating the metal salts and the residual slag during a separation process, wherein the metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; and repeating an extraction cycle, comprising: exposing the residual slag to the acid, wherein the residual metal slag comprises one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof; mixing the residual slag and the acid to produce an acid-coated residual slag; reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process comprising providing the acid-coated residual slag an additional reaction time of at least 24 hours; and separating the additional metal salts and the secondary residual slag during a second separation process, wherein the additional metal salts comprise one or more of iron, vanadium, copper, zinc, lithium, or any combination thereof; and wherein the extraction cycle is conducted or repeated 1 time to 5 times; and wherein one or more of the metals of the metal salts is independently recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the metal in the metal slag.

Clause 43. The method according to any one of Clauses 40-42, wherein the acid comprises sulfuric acid having a concentration of greater than 90 wt %, and the acid is mixed with the metal slag to produce the acid-coated slag at an amount or concentration in a range from about 25 wt % to about 50 wt % relative to the weight of the metal slag.

Clause 44. The method according to any one of Clauses 40-43, wherein prior to exposing the metal slag to the acid, further comprising exposing the metal slag to a size reduction process, wherein the size reduction process comprises milling, grinding, smashing, crushing, or combinations thereof the metal slag, and wherein the metal slag is reduced to a particle size of P80 0.25 inch or less during the size reduction process.

Clause 45. The method according to any one of Clauses 40-44, wherein the metal slag further comprises titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof, and wherein the metal salts comprise one or more of titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

Clause 46. The method according to any one of Clauses 40-45, wherein the metal comprises iron, and wherein the iron is recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the iron in the metal slag.

Clause 47. The method according to any one of Clauses 40-46, wherein the metal comprises copper, and wherein the copper is recovered from the metal slag at about 80 wt %, about 85 wt %, about 90 wt %, or greater relative to an original amount of the copper in the metal slag.

Clause 48. The method according to any one of Clauses 40-47, wherein the acid comprises sulfuric acid, hydrochloric acid, nitric acid, oxalic acid, citric acid, or any combination thereof.

Clause 49. The method according to any one of Clauses 40-48, wherein: the acid-coated slag is maintained at an ambient temperature and ambient pressure during the reaction process; or the acid-coated slag is maintained at a temperature in a range from about 5° C. to about 40° C., and at a pressure in a range from about 0.9 atm to about 1.1 atm during the reaction process.

Clause 50. The method according to any one of Clauses 40-49, wherein the reaction time is in a range from about 2 days to about 150 days, and wherein the acid-coated slag is contained on a pad, a platform, a base, or in a container during the reaction process.

Clause 51. The method according to any one of Clauses 40-50, further comprising maintaining a water concentration of the acid-coated slag in a range from about 1 wt % to about 5 wt % during the reaction process, wherein the water concentration is relative to the weight of the metal slag.

Clause 52. The method according to any one of Clauses 40-51, further comprising combining water with the metal slag and the acid to produce the acid-coated slag, wherein: the water is combined with the metal slag and/or the acid prior to producing the acid-coated slag; the water is combined with the metal slag and the acid when producing the acid-coated slag; and/or the water is combined with the acid-coated slag during the reaction process.

Clause 53. The method according to any one of Clauses 40-52, wherein the separation process comprises: dissolving the metal salts in water to produce an aqueous metal salt solution; and separating the aqueous metal salt solution from the residual slag, wherein the separation process comprises a filtration process, a washing process, a decantation process, a centrifugal process, or any combination thereof.

Clause 54. The method according to any one of Clauses 40-53, wherein the water and the metal salts are combined to produce the aqueous metal salt solution, and wherein the water is combined at an amount in a range from about 4 times to about 20 times in weight relative to the weight of the metal slag.

Clause 55. The method according to any one of Clauses 40-54, wherein the aqueous metal salt solution is exposed to a fine filtration process after the separation process, wherein the fine filtration process removes solid particulate from the aqueous metal salt solution, and wherein the solid particulate comprises silica, calcium sulfate, or any combination thereof.

Clause 56. The method according to any one of Clauses 40-55, further comprising exposing the aqueous metal salt solution to a purification process to separate the metal salts from the water, wherein the purification process comprises a solvent extraction process, a precipitation process, an ion exchange process, or any combination thereof, and wherein the metal salts comprise one or more salts of iron, vanadium, zinc, antimony, copper, lithium, arsenic, titanium, cobalt, magnesium, manganese, chromium, aluminum, tungsten, lead, silver, nickel, tin, or any combination thereof.

Clause 57. The method according to any one of Clauses 40-56, wherein a raffinate is produced from the purification process, and wherein at least a portion of the raffinate is transferred, recycled, or otherwise introduced into an upstream process, to the metal slag, to the acid-coated slag, or any combination thereof.

Clause 58. The method according to any one of Clauses 40-57, wherein: at least a portion of the water of the aqueous metal salt solution is separated from the aqueous metal salt solution and transferred, recycled, or otherwise introduced into an upstream process, to the acid-coated slag, back to the metal salts to produce additional aqueous metal salt solution, or any combination thereof; and/or at least a portion of the acid is separated from the acid-coated slag and transferred, recycled, or otherwise introduced into an upstream process, to the metal slag to produce additional acid-coated slag, or any combination thereof.

Clause 59. The method according to any one of Clauses 40-58, wherein an extraction cycle is conducted or repeated 1 time to 5 times, and wherein the extraction cycle comprises: exposing the residual slag to the acid, wherein the residual metal slag comprises one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof; mixing the residual slag and the acid to produce an acid-coated residual slag; reacting additional metals in the residual metal slag with the acid to produce additional metal salts and a secondary residual slag during an additional reaction process comprising providing the acid-coated residual slag an additional reaction time of at least 24 hours; and separating the additional metal salts and the secondary residual slag during a second separation process, wherein the additional metal salts comprise one or more of iron, vanadium, zinc, antimony, copper, lithium, arsenic, or any combination thereof.

Clause 60. The method according to any one of Clauses 40-59, wherein the metal slag comprises a black mass derived from recycled batteries, wherein the black mass comprises lithium, copper, cobalt, nickel, manganese, or any combination thereof.

Clause 61. The method according to any one of Clauses 40-60, wherein the black mass further comprises graphite, a binder, or a combination thereof.

Clause 62. The method according to any one of Clauses 1-61, further comprising combining a coordinating agent with the metal slag and the acid to produce the acid-coated slag, wherein: the coordinating agent is combined with the metal slag and/or the acid prior to producing the acid-coated slag; the coordinating agent is combined with the metal slag and the acid when producing the acid-coated slag; and/or the coordinating agent is combined with the acid-coated slag during the reaction process.

Clause 63. The method according to any one of Clauses 1-62, wherein the coordinating agent comprises an alkaline metal halide salt, and wherein the coordinating agent has a concentration in a range from about 0.1 wt % to about 5 wt %, relative to weight of the metal slag.

Clause 64. The method according to any one of Clauses 1-63, further comprising combining an oxidizer with the metal slag and the acid to produce the acid-coated slag, wherein: the oxidizer is combined with the metal slag and/or the acid prior to producing the acid-coated slag; the oxidizer is combined with the metal slag and the acid when producing the acid-coated slag; and/or the oxidizer is combined with the acid-coated slag during the reaction process.

Clause 65. The method according to any one of Clauses 1-64, wherein the oxidizer comprises a hypochlorite, a peroxide, or a combination thereof, and wherein the oxidizer has a concentration in a range from about 0.1 wt % to about 5 wt %, relative to weight of the metal slag.

While the foregoing is directed to embodiments of the disclosure, other and further embodiments may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. All documents described herein are incorporated by reference herein, including any priority documents and/or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the present disclosure have been illustrated and described, various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including” for purposes of United States law. Likewise, whenever a composition, an element, or a group of elements is preceded with the transitional phrase “comprising”, it is understood that the same composition or group of elements with transitional phrases “consisting essentially of”, “consisting of”, “selected from the group of consisting of”, or “is” preceding the recitation of the composition, element, or elements and vice versa, are contemplated. As used herein, the term “about” refers to a +/−10% variation from the nominal value. It is to be understood that such a variation may be included in any value provided herein.

Certain embodiments and features have been described using a set of numerical upper limits and a set of numerical lower limits. It should be appreciated that ranges including the combination of any two values, e.g., the combination of any lower value with any upper value, the combination of any two lower values, and/or the combination of any two upper values are contemplated unless otherwise indicated. Certain lower limits, upper limits and ranges appear in one or more claims below.