Cut-and-Fill Stoping

Cut-and-fill stoping is appropriately suited to irregular orebodies with wall rocks that cannot support loads over large stoping heights. Since backfilling adds a step to the mining of each slice of ore, the ore has to have a grade high enough to offset this added cost.

 The stope is mined upward from below, in horizontal cuts or slices. Each slice is blasted on to the floor of the stope and the ore is mucked to the hole of the stope mill, which leads to the chutes in the haulageway below. The mill hole is a vertical opening and is usually lined with steel. Mining a slice leaves a space along the complete width and length of the stope.

After the manway and mill hole have been extended, the stope is backfilled, leaving enough space to work above. Most of the time the top portion of each new layer of fill is a concrete mix that provides a solid work floor to support heavy equipment. This process is repeated until the level above is reached, or to some pillar line that is predetermined.

Cut-and-fill is very flexible. Ore production can be done in one part of the stope while on the meantime the other part is being filled. It also permits miners to mine ore selectively and waste with little dilution. By identifying waste, it can be left behind in the stope as fill. It is also quite safe with a component ore rock and proper support.