To increase storage capacity and reduce the ongoing
problems with raises, IMC Potash designed and installed a succession of three stackers. Stackers are ore storage systems that windrow ore on the floor parallel to a conveyor and then reclaim that ore upon demand. A stacker weighs up to 4S tonnes (SO t) and trams itself horizontally on rail in a gallery up to 600 m (2,000 ft) long. It is composed of a tripper (which removes the ore from the belt), a stack belt (which deposits ore into the center of a room), a feeder (which picks the ore back up), and a reclaim belt (which returns the ore to the conveyor). Stackers can reclaim ore at a controllable rate independent of the rate of incoming ore. The largest stacker underground holds about 4,SOO tonnes (S,000 t) of ore, can stack ore at the rate of about 4S tonnes/min (SO t/min)i and recovers ore at a precise rate to meet hoisting requirements.