Question

Differentiate between the following:
A. Minerals and ores
B. Calcinations and roasting

Answer 1

Hint: Metals from ore can be easily extracted as compared to mineral. Calcinations do not involve air during heating and roasting is done in the presence of air.

Complete answer:
Metallurgy is the branch of chemistry which deals with the method of extraction of metals from their ores. Metal is the element which tends to make positive ions. Minerals are defined as the various compounds of metals which occur in the earth’s crust and are obtained by mining. A mineral may be of a single compound or mixture. On the other hand, ores are defined as the minerals from which metal can be profitably and easily extracted. We can say ore is a mineral through which metal can be extracted in a low cost manner and also effectively and efficiently. Matrix is defined as the undesirable impurities present in an ore. Matrix is also known as gangue.
After the concentration of ore or the removal of impurities from the ore, concentrated ore is obtained. Now the concentrated ore is converted into oxide form via roasting or calcination. Calcination is a process in which ore is heated, generally in the absence of air or oxygen to expel the water from a hydrated or hydroxide ore and oxide or carbon dioxide form a carbonated ore at temperature below their melting points. Calcinations help to remove moisture, organic matter destroyed, hydroxide and carbonated ore of Aluminium and Calcium respectively are converted to their respective oxides. On the other hand, Roasting is the removal of the excess sulphur contained in sulphide ore in the form of sulphur dioxide by heating in an excess supply of air. The concentrated sulphide ore in roasting is heated in a reverberatory furnace below its melting point in the presence of air with or without the addition of external substance.

Note: Oxygen is the most abundant element found in the earth’s crust and Aluminium is the most abundant metal found in the earth crust.