The World’s Deepest Gold Mine is cooled with Slush

A South African goldmine similar to the one in this article.
Photo by Babakathy

There is a certain amount of argument as to what is the world's deepest gold mine, but there is no doubt it is found in the Witwatersrand of South Africa. The latest contender for the title of world's deepest mine is the Mponeng mine of the West Wits district of the Witwatersrand.  The mine's name is derived from the Sotho word for “Look at me.” At 13,000 feet this presently holds the record as the worlds deepest mine. This record does not only apply to gold but any other product such as uranium that is mined from the deepest recesses of the earth.

This mine is so deep the only way it can be cooled to the highest temperature allowed by South African law of 83°F at the mine face is by refrigeration that makes a mixture of ice and water that we call slush.  There is several refrigeration units deep in the bowels of the mine made by IDE Industries headquartered in Israel that make slush as part of a scheme to make fresh water from sea water . The slush is held in readiness in underground reservoirs until it is piped to the working face of the mine.  After it has done its job of cooling the mine the warm water is pumped back to the surface where it originally came from by large electric pumps using tremendous amounts of electricity where it is allowed to cool off.

The mine contains 230 miles of shafts and tunnels that take the workers as much as 90 minutes to reach the working face of the mine allowing only five hours per shift at the working face.  The shaft is split into two sections causing the workers to have to walk to the second shaft before they can continue their journey to the bottom of the mine.  Most of the trip continues on rails that carry men, equipment and ore.  The final part of the journey is made in low tunnels that cause the men to walk hunched over with their miners lamps to brush the ceiling of the tunnels.  Some of the time they have to go down narrow stairways leading into the depths of the mine.

At present this mine is the deepest on earth, but it is possible to extend the depth of a mine to 33,000 feet with most of the work being done by robots.  This mine makes it too all apparent that no real changes have taken place in deep mining for more then 100 years, a situation that must change if we are going to continue extracting minerals from the depths of the earth.

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