Question

(a) What is the difference between a mineral and an ore?

(b) Differentiate between roasting and calcination process in metallurgy.

Answer 1

(a) Difference between a mineral and an ore :

	Mineral	Ore
(i)	Natural materials in which metals occur in the forms of their compounds	Minerals from which metals are extracted  profitably.
(ii)	NaCl, Mica.	Bauxite (AI2O3.2H2O)

(b) Difference between Calcination and Roasting are :

Caleination	Roasting
It is a process of heating ore in absence of air so as to remove moisture and volatile impurities and to convert  carbonate ores into oxides.	It is a process in which ore is heated in the  presence of air so as to obtain metal oxides, which can be reduced easiiy to get free metal.Sulphide ores are converted into oxides by roasting them in air.