The most common types of ore, copper oxide and copper sulfide, undergo two different processes, hydrometallurgy and pyrometallurgy, respectively, due to the different chemistries of the ore. Copper oxides are more abundant near the surface, but are considered low-grade ore, with a lower concentration of copper.
In metallurgy, refining consists of purifying an impure metal. It is to be distinguished from other processes such as smelting and calcining in that those two involve a chemical change to the raw material, whereas in refining, the final material is usually identical chemically to the original one, only it is purer.
Open-pit, underwater, and underground mining. These are the three main methods of mining we use to extract our products from the ground.
Mining operations and refining ores for the manufacturing process will result in environmental issues and impacts; these include high energy use, physical disturbance of the landscape and pollution from toxic emissions, which may affect land, water and air.
This usually involves removing any unwanted impurities and further processing to increase the concentration of the economic mineral. Metallic minerals may be smelted or refined to produce metal close to the mine, or the concentrate may be transported to another site for further processing.
Mineral processing can involve four general types of unit operation: comminution – particle size reduction; sizing – separation of particle sizes by screening or classification; concentration by taking advantage of physical and surface chemical properties; and dewatering – solid/liquid separation.
Pyrometallurgy, extraction and purification of metals by processes involving the application of heat. The most important operations are roasting, smelting, and refining. Roasting, or heating in air without fusion, transforms sulphide ores into oxides, the sulphur escaping as sulphur dioxide, a gas.