difference between calcination and roasting
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Answers
Calcination is a process where the air might be supplied in limited quantity, or the ore is heated in the absence of air. Roasting includes heating of ore lower than its melting point in the presence of oxygen or air. Calcination involves the thermal decomposition of carbonate ores.
Answer:
Calcination is the process of heating the ore below its melting point in absence of air to remove volatile impurities like arsenic etc.
Roasting is the process in which the ore is heated below its melting point in presence of air to oxidise the impurities. Ex: carbon, sulphur etc removed as their gaseous oxides.
1. In the process of roasting, ore is heated above its melting point in the presence of air or oxygen while in calcination, ore is heated above its melting point in the absence of air or very limited amount of oxygen supply
2. Roasting is mostly done for sulphide minerals while calcination is mostly applied in decomposition of carbonate ores.
3. Roasting is not used for dehydrating an ore while calcination can be used to drive out moisture from an ore.
4. In roasting, sulphur dioxide is released while in calcination carbon dioxide is released.