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CARLETONVILLE (miningweekly.com) – South Africa’s Witwatersrand basin contains another 1.3-billion ounces of gold, almost as much gold as has been mined there since 1886 – but miners can only get to another 200-million ounces of it using today’s mining methods.
If the industry does not come up with a new way of mining, more than a trillion dollars worth of gold will not be mined, because the 1.1-billion ounces in question are either below the cutoff for the current mining method, or they are at depths where there are no technical solutions to get to mine those ounces.
Moreover, safety has reached a plateau and unless significant change is made to what creates this plateau, death and injury in mines will continue, which is totally unacceptable.
There is thus an absolute need to change – and senior VP technology and projects Shaun Newberry is at the forefront of an AngloGold Ashanti move that could result in all three billion Wits basin ounces being mined and not merely 1.9-billion of them.
Individual technologies currently under investigation will make a significant impact on the current mining method, where reverse circulation drilling will ensure enhanced information and better planning.
Reef boring and ultra high strength backfill will drastically reduce risk and technologies will also combine to allow AngloGold Ashanti to extract additional gold which was previously lost to the current mining method, Newberry told Mining Weekly Online in a one-on-one interview at the TauTona gold mine, where testing of new technology is under way.
The technology that AngloGold Ashanti is prototyping and which has already produced nearly 2 000 oz of gold is aimed at safely mining all of the gold, only the gold, all the time, without drilling and blasting.
The new mining method requires exponentially more geological information to deploy the proposed new method.
Rich shaft pillars, which cannot be safely mined using current mining methods, are being targeted as quick wins that will be mined and backfilled with ultra high strength backfill.
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