Question

Name one chief ore each of copper and aluminium. Name the method used for the concentration of these two ores.

Answer 1

Hint: The natural material in which metallic compounds occur in earth’s crust is known as a mineral. The minerals from which the metal can be readily and economically extracted are called ore.

Complete answer:
> Metals occur in nature sometimes in the free state but mostly they occur in combined states. In a combined state, metals are associated with other impurities such as sand, clay, rocks etc. A naturally occurring material, containing metallic compounds, in the combined state is known as a mineral. Ore is a mineral that contains metal in considerable amounts so all ores are minerals but all minerals are not ores.
> The chief ore of copper is:
Copper pyrite (${\text{CuFe}}{{\text{S}}_{\text{2}}}$) is the chief ore of copper. It contains 2 - 3 % of copper and rest is impurities like silica, iron sulphide, etc. It is a yellow coloured mineral containing copper in sulphide form. It is also known as chalcopyrite.
> The method used for the concentration of copper ore is:
To extract the copper from copper pyrite ore, a froth flotation method is used. This process is especially suitable for the concentration of sulphide ores. The process is based on the different wetting characteristics of the ore and the gangue particles (impurities) with water and oil. In this process, the ore is wetted with oil while gangue particles are wetted with water. The finely crushed sulphide ore mixed with water and a small amount of pine oil.
> The chief ore of aluminium is:
Bauxite (${\text{A}}{{\text{l}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{.2}}{{\text{H}}_{\text{2}}}{\text{O}}$) is the chief ore of aluminium from which aluminium is extracted. In the earth crust aluminium is found in a combined state as oxide. It contains around 40% alumina.
> The method used for the concentration of aluminium ore is:
To extract the aluminium from the bauxite ore leaching process is used. The leaching process is based on difference solubility ore and other impurities. In this process, insoluble impurities can easily be separated from soluble ore. For the industrial purpose, the Bayer process is used to extract the alumina from bauxite ore.
Thus,
> Copper pyrite (${\text{CuFe}}{{\text{S}}_{\text{2}}}$) is the chief ore of copper and the froth flotation method is used for concentration of this ore.
 Bauxite (${\text{A}}{{\text{l}}_{\text{2}}}{{\text{O}}_{\text{3}}}{\text{.2}}{{\text{H}}_{\text{2}}}{\text{O}}$) is the chief ore of aluminium and the leaching method is used for concentration this of ore.

Note: There are many minerals which contain metallic compounds but only minerals from which we can extract the metals economically in a sufficient amount are known as ore. Bauxite and clay are two minerals of aluminium, but aluminium can be profitably extracted only from bauxite and not from clay. Hence bauxite is the ore of aluminium and clay is the mineral. Similarly, pyrite is the principal ore of the copper out of the other minerals of copper. The method used for the concentration of ore depends on the type of ore.