Ore is taken out of the ground
|Holes are drilled in the ground (if it’s an open-pit mine) or in the rock-face (if it’s an underground mine), and explosives are placed in them to blast it open. The resulting explosions leave huge quantities of copper-bearing rock – also known as ore.
Ore is broken down into smaller pieces
|The large pieces of ore are collected by haul trucks and taken to a mill, a large rotating device which makes the pieces smaller through crushing and grinding. There are two types of copper ore (sulphide ore and oxide ore), and each is treated differently in order to liberate the copper inside.
Sulphide ore – treatment process
The copper is liberated from the sulphide ore through a chemical processes called flotation. The resulting copper mixture is called concentrate, which is a grey-black powder that looks a bit like ash. It is roughly 30% copper, and may also contain traces of gold and silver.
The copper concentrate then goes to a smelter, where it undergoes several chemical processes at high heat in order to remove iron and sulfur. (The resulting sulphur dioxide emissions are captured and recycled into sulphuric acid, which can be used by the mine.) The concentrate is then purified further through a refining process. The copper is now nearly 99.99% pure, and is cast into distinct shapes, ready for shipping to world markets.
Oxide ore – treatment process
|Copper is liberated from oxide ore through a chemical process known as leaching and solution extraction. The final step is electrowinning, which uses an electrical current to produce sheets of copper that are 99.99% pure and ready for shipping to world markets.
The copper is used in many applications
|Copper is strong, and has excellent thermal and electrical properties. It is used mainly in electrical wiring (60%), roofing and plumbing (20%) and industrial machinery (15%). Copper is present in our homes, our cellphones, our computers and our cars – the average car contains 1.5 km of copper wire. It is also used in healthcare equipment because of its anti-bacterial properties.