Tracer diffusion device, system for tracing development of water conducting fracture zone and relataed method

Mining method without coal pillars with roof-cutting and roadway retaining

Brine extraction well system

Method for constructing dam inside dump of inner-dump strip mine

Flood protection for underground air vents

Liquid taking device and liquid taking method

System and method for forming a cavity in a backfilled stope

A WELL SYSTEM

Fissured substrata water pumping apparatus and method

Underground Silo System for Storing Liquids

Method for distributed storage and use of underground water in mine

Pump apparatus

Mine dewatering system and method

Method and product for absorbing and consolidating nuisance water or slurry accumulations

Method for dewatering coal mine goaf by crossing neighboring goaf