New Drill System to Revolutionise African Gold Mining: By Ian Cockerill, Chairman of Petmin and Former Chief Executive of Gold Fields. He Has Been Advising Peterstow on Taking Its Technology to Market
Cockerill, Ian, African Business
Unlike many of the world's major industries, which have proven adaptive to changing circumstances, gold mining has changed little in the past 100 years, despite growing pressure on business to become more sustainable. Mines consume vast amounts of power and water, which are no longer plentiful and cheap, as they once were. South Africa, in particular is struggling to meet power demands. People have also started asking serious questions about the environmental impact of mining.
Mines, along with other major consumers of power across Africa, are now obliged to cut power consumption, and there is likely to be increasing pressure, and legislation, to ensure they do more.
There are huge inefficiencies in the processes of hard rock mining. Power compressors that sit on the surface of the mine guzzle electricity, which is fed down the shaft to cool the operations and operate all the machinery that goes into a modern underground operation. A key power consumer is the rock drill itself; there are 65,000 of these in South African gold, platinum and chrome mines, drilling some 700,000 blast holes every day. Almost all of these are powered by the compressors sitting up to 4km above them.
A single large deep-level mine can easily run up an electricity bill of R100m ($14.6m). For every 100kW put into a compressor to create the pressure needed to compress the air for drills, only about 1kW arrives at the intended source. The rest is simply lost along the way.
Some of these problems are starting to be addressed by a company called Peterstow Aquapower, whose goals I have supported since the idea was put to me years ago. Peterstow Aquapower has developed a drilling system for hard rock deep-level mining that uses less than 0.01% of the energy required by some existing systems and 60% less water. The technology was conceived by Douglas Barrows 20 years ago, who now, along with his son Alan, has now opened a world-class manufacturing plant in Swaziland to produce the technology.
The system is based on patented closed-loop water hydraulic technology and modular power packs. The power pack contains a motor that turns a water hydraulic pump. This circulates the water through the drill. When the drill is off, water is circulated at normal pressure and no energy is wasted. When the drill is turned on, Peterstow's innovative design uses a clever piece of precision engineering to create the high pressure needed to drive the drill.
Such a system eliminates the expensive and inefficient process of compressing the air for drills, as the system runs on ordinary tap water and pressure is created by a single unit which is taken down the mine. …