Mud Injection

in mining a means of combating underground fires by delivering mud slurry (a mixture of water with clay or fine-grain sand) to mine workings and worked-out areas. Fires are extinguished with mud through individual wells drilled from the surface, through group wells and a network of underground pipelines, and through underground wells. A distinction is made between preventive mud injection and mud injection for extinguishing fires. In preventive mud injection the mud mix fills hollows and cracks and pre-vents air from getting to the fire-hazard area, thus averting spontaneous combustion of the mineral involved.