Gold Mines Reach New Depths; Industry Considers Space Age Methods

Article excerpt

Miners in spacesuits. Robots digging round the clock. Colonies of men living and working for days under three miles of solid rock.

These are a few of the ideas floating around South Africa's gold industry as it sets out to explore a 21st century frontier - ultra-deep mining.

South Africa has the deepest mines in the world, but many shallower areas are mined out and the industry is probing previously unthinkable depths of three miles.

The challenge has drawn mine executives, union leaders, government officials and scientists into a massive research project called Deepmine.

"We'll be looking at everything from rock engineering to things that are real science fiction," Deepmine chairman Mr Keith Spencer said.

The prize for going deeper than ever before is a vast reserve of gold at least equal to what has been mined already.

It would extend the life of South Africa's mines well into the next century and Deepmine's expertise could be exported overseas.

But getting to three miles and working there presents an enormous challenge.

Deepmine has just approved several projects to tackle issues like shaft design, geology, financing, health and safety.

The temperature at three miles is a blistering 70 degrees Celsius, while the pressure could pose other health problems for miners.

Most mines use huge refrigeration units to pump cool air into tunnels as deep as 2.3 miles.

But cooling costs at three miles may be too high, prompting experts to consider outfitting miners in climate-controlled suits. Others suggest using robots operated by remote control from the surface, able to mine 24-hours a day.

Some futuristic thinkers have even proposed underground living quarters where miners could work and live for several days, much like an oil rig at sea.

"We'll look at everything, but probably nine of out every ten science fiction ideas we'll throw away," said Mr Spencer, who is also technology chief at Gold Fields.

Deep level mining is not new in South Africa.

Anglogold, Gold Fields and Durban Roodepoort - the three gold companies in Deepmine - currently operate mines at more than 1. …