Abstract: The mining method of this invention is particularly suitable for the underground extraction of large mineral deposits, wherein a subsidiary road is formed perpendicularly to the work face from which the mineral deposit is to be removed. A boundary subsidiary road is formed substantially perpendicularly to the subsidiary road, a first mine tunnel is formed by removing the mineral deposit from the work face along the subsidiary road until the boundary gate road is reached. Then the material around said first mine tunnel is collapsed to fill the same along the subsidiary road and the collapsed matter is consolidated along the subsidiary road. Finally a second mine tunnel is formed along the subsidiary road. The second mine tunnel can be horizontally or vertically adjacent to the first mine tunnel.

Abstract: In mining a heavy coal seam that must be excavated in several benches, the excavation of the uppermost bench is accompanied by the introduction of a cementitious slurry into the resulting stope for consolidating the waste rock present therein, preparatorily to the excavation of the next-lower bench, and proceeding in like manner with the second bench if a third one is to follow. The cementitious slurry comprises burnt or slaked lime, and/or portland cement, suspended in water in a quantity of about 10 to 60% by weight and preferably together with a small percentage of chlorides of one or more alkali or alkaline-earth metals, to which ceramic aggregates at large specific surface such as mineral ashes, slag, sand or dolomite powder may be added in a quantity of up to about 30% of the weight of the water.