JOHANNESBURG (miningweekly.com) – Gold major AngloGold Ashanti is installing turbines in underground mines to boost energy regeneration, as part of a strategy of recovering electricity without spending significant amounts of capital.
“What we’ve done is put in energy regeneration and capture plants in the form of turbines at two of our mines,” says AngloGold Ashanti COO South Africa Mike O’Hare (also watch attached video produced by Creamer Media Mining Weekly Online).
Largely by re-engineering mine cooling and refrigeration, the JSE- and NYSE-listed gold-mining company has managed to cut consumption of electricity from the national power grid by 20% in the last six years, while also working closely with State electricity utility Eskom to lower power consumption during peak periods by shifting its pumping and rock hoisting loads.
In the event of not having any access to grid electricity at all, it resorts to its own emergency standby equipment to hoist underground employees to surface.
Building its own power stations, as Sibanye Gold is planning, is currently being eschewed.
It is, however, continuing to look at alternative sources of energy, particularly green energy, including solar and wind farms, to increase its standby generating capacity, whereas Sibanye may build a R3-billion, 150 MW solar power plant and is also investigating the feasibility of establishing its own coal-fired power stations that could contribute an additional 200 MW and 600 MW.
Turbines that mimic Pelton-wheel-type technology first used by the ancient Egyptians, has for long been used to recover the kinetic energy inherent in water descending down deep-level South African gold mines, with electricity regenerated in this way used to pump water back to surface for re-cooling.