The underground fixed plant is a series system of components which together are capable of moving 36000 tonnes per day of ore from the underground.
Four double toggle jaw crushers with an opening of 2.13 m x 1.68m receive rocks from the cave up to 1.2 metres in any one dimension. All the ore passes through the crushers and is reduced to minus 220mm in size. This ore is then fed via four short sacrificial conveyors onto the main decline conveyor.
The main decline conveyor is 1330 metres long and is fitted with a 1050 mm wide ST2000 steel cord belt. Power is provided by a tandem 750 kw drive capable of driving the conveyor through a VSD at up to 4.3 m/s. This conveyor delivers the ore to two shaft silos where a unique belt loading system is employed to load the skips. Here PLC controlled logic ensures that not only is the time of each loading cycle optimized but the mass and volume of each skip is also maximized depending on ore conditions.
Two Koepe winders mounted on top of a 106 metre high headgear provide the vertical lift needed to transport in excess of 30000 tonnes per day from underground to the surface stockpiles. The total length of wind is 1282 metres and each skip has a payload of 32 tonnes. Power is provided by two integral Siemens motors rated at 6000 kw each. Hoisting speed is 18 m/s and each cycle lasts 118 seconds.