ABSTRACT
Base metals broadly refer to a category of non-ferrous metal commodities typically consisting of copper, nickel, cobalt, lead, zinc and mercury. Generally, copper-bearing minerals are extracted from the copper-bearing ore body using three principal techniques: open-pit mining, underground mining and in situ leaching. After the mining process, the run-of-mine ore is conveyed to the beneficiation plant. Typically, the beneficiation processes include crushing and grinding followed by chemical and/or physical processing and separation stages in order to upgrade the copper content into a concentrate. The separation process takes place in flotation banks where special reagents are added to alter the hydrophobicity properties of the sulphide minerals. Nickel is generally produced from sulphide minerals, and from laterite and saprolite ores. Cobalt ores exist mainly as mixed sulphides. Platinum group elements are very rare in the earth's crust, and their scarcity technically qualifies them to be classified as precious metals.
