Imagine a world without copper. Without it, electrical wires and pipes would disappear overnight. Industries can’t exist without the malleable metal, nor can a thousand essential applications. Meeting their needs, the Olympic Dam mining complex, located in Southern Australia, mines over 200,000 tonnes of the industry-essential metal every year. Clearly, Australia has a vested interest in copper mining, so the nation’s mining experts know all there is to know about its extraction.
Let’s stay away from Olympic Dam. Uranium is extracted there, and we want to stay far away from this radioactive element. Let’s head north and east to Queensland, over to the Mount Isa copper mines. The orange-brown metal is mined from open-face pits around the world, especially in Chile. In Australia, however, underground mining technology rules. Like other ore mining techniques, the equipment used here needs to extract the copper ore, break it down, and get it up to the surface, where it can be processed. The release of pure copper, liberated from the ore, occurs when the crushed materials are dissolved in sulphuric acid solutions.
Deep lode copper sulphides are trapped in mineral deposits deep below Australia’s soil. Closer to the surface, the ore is found in its metal-diluted oxide form. The chalcopyrite (metal sulphide) type contains more copper, so Australian mines sink deep into the earth in search of the popular metal. The problem, though, is that copper isn’t found in dense quantities within those ore deposits. To deal with this issue, crushers create beneficiated (densely packed) mountains of copper-rich rock.
A standard ore crushing setup, a primary crusher, in other words, will easily break down the large chunks of chalcopyrite, but where does the process go from there? The mine manager wants a gritty pile of dust that will sift through his fingers. Sending the discharge to a group of mill crushers, it’s their barrel-shaped housings that further reduce the extracted and crushed rock pile. The minerals are next mixed and blended, added to a paraffin pool, and exposed to what’s known as the froth flotation phase of the extraction operation.
Everything about copper mining in Australia is finely processed. At the process entrance, primary and secondary gyratory crushers reduce the mineral load. There could even be a tertiary gyratory crusher in the mix, so a fine grain size is assured. The granular stream is screened, but the media used here uses incredibly tiny apertures. Wet screening and cleaning equipment dominate. From here, cyclone equipment and thickeners take the copper to flotation tanks, where it’s prepped for the chemical treatment phase.