Question

The difference (s) between roasting and calcination is/are:

• A. roasting is highly endothermic while calcinatino is not
• B. partial fusion occurs in calcination but not in roasting
• C. calcination is performed in limited amount of air but roasting employs excess air
• D. combustion reaction occur in roasting but not in calcination

Answer 1

Answer: (C), (D)

The correct options are
C combustion reaction occur in roasting but not in calcination
D calcination is performed in limited amount of air but roasting employs excess air

(A) Roasting is an exothermic process. Thus option A is incorrect.
(B) During roasting and calcination, the ore is heated to a temperature which is below its melting point. Thus option B is incorrect.
(C) Limited air is used during calcination whereas excess air is used during roasting. Thus option C is correct.
(D) During roasting, combustion reaction occurs but during calcination, carbonate ores decompose to metal oxides and carbon dioxide. Thus option D is correct.