MINING DISCOVERY

Hawke's Bay Tribune, Volume XVII, 19 November 1927, Page 10

MINING DISCOVERY

7650 FEET BELOW GROUND.

MAN '8 DEEPEST.

BRILLIANT NEW INVENTION.

Johannesburg, South Africa, Oct. 15. Ice-cooled air is enabling men to work 7650 feet underground—tho deepest point to which man has ever burrowed towards the earth’s core—in the Turf shaft of the Village Deep gold mine, Johannesburg. Apart from economic factors it was once thought by experts that deep level mining would reach its limit at 7500 feet because of the high temperatures which obtained al the lowest points. Statistics show that, in tne Village Deep mine there is an increase in the temperature of one degree Fahrenheit for every 254 feet of vertical depth.

At the deepest point of the Village Deep the rock temperature is already equal to that of the human body, and it is calculated that at a depth of 9000 feet the temperature will be 103.8 degrees. Thanks to a new method of ice cooling, work can be carried on to almost any depth. So far as is known, the Village Deep is the only mine in the world where ice is utilised for cooling purposes. Eighteen months of experiments have proved the system to be remarkably successful and to-day the mine is using more than four tons of ice daily. Th e method consists of placing the ice in the delivery ends of 15-inch ventilation pipes. The air coming from the pipes passes over the ice and is then concentrated on the spot where work is progressing. The method has proved most effective, and has succeeded in lowering the temperature at least seven degrees. By increasing the quantity of ice. a reduction of no less than sixteen degrees has been attained.