A mine is an industrial enterprise that extracts minerals using an underground mining system. When organizing mines of huge diameter, the vertical shaft cuts into the bowels of the earth, extracting its hidden wealth to the surface.
Expensive, complex and dangerous mining method justifies the extraction of only very expensive raw materials, for example, gold-bearing rock. The costs will pay off in full even if the content of valuable metal is 0.1-5 g per ton of rock.
Leader of Anglohold
It is such a gold mine that was built in Africa by AngloGold Ashanti near Johannesburg, in its southeastern suburb of Boksburg over a hundred years ago. The depth of its development reached 3585 m. Over time, it yielded the palm to the even deeper Savuk mine of the same company. Savuka was built 80 km southwest of Johannesburg. In 2002, its depth exceeded 3700 m.
In 1962, 50 km from Johannesburg, the third mine, Tauton, was launched, which means “the great lion”. In 2007, its depth was 3778 m, which allowed it to take a place in the Guinness Book of Records.
Today TauTona Mine, the third mine of the Western Deep Mine, is the deepest in the world. In 2009, the depth of its development was increased to 3910 m. At the same time, the gold grade increased to 9.8 g / t in comparison with the former 5.8 g / t. There is information that in the future it is planned to increase the production to 4300 m.
This is the most gold-bearing vein in South Africa. Half a century of gold production amounted to 1200 tons. During this time, 800 km of tunnels were laid with an annual deepening of 80 m. More than 6000 people are involved in the mine. Working at this depth is not easy for miners. The bottomhole temperature exceeds 55 ° C, which, according to the manager, can be lowered to 28 ° C. The seismically dangerous mining area leads to frequent collapses of tunnels and death of people (according to official data, up to 5 people annually).
There is a three-stage development scheme at the deposit: the main shaft of the mine reaches the depth of the gold ore, a second "blind" shaft is laid from its lower mark, and a third from it. Hoisting mechanisms move at a speed of 16 m / s or 58 km / h, while the delivery time of workers to the place of production is at least 60 minutes. This includes the time of transfer from one pillar to another.
It is impossible to make the descent continuous due to the limited capabilities of the mechanisms. In addition to the weight of the cage of the main lift, which can accommodate 120 people, the weight of the skips and the weight of each of the 2,100 meter cables, which is 21.5 tons, are taken into account. The cables are carefully checked monthly for the slightest deformations, with their subsequent replacement.