Vaal Reefs Exploration and Mining Company Limited operates one of the
largest producing gold mines in the world. The annual production of 76
tons of gold from 12 million tons of ore treated is obtained mainly from
underground sources. Daily some 6.6 km of stope face is blasted and 41 tons of explosives is
used to break the rock. The mine employs 45 000 men of whom 35 000
work underground. The company operates nine large vertical shaft systems of which seven
extend more than 2000 m below surface and an eighth, currently being sunk, will bottom at 3700 m below surface.