Question

Give reasons for the following: Roasting of the concentrated ore is carried out in the presence of excess air, while calcination of the concentrated ore in the absence or limited supply of air.

  • Metallurgy
WhatsApp

Answer

Calcination is carried out on carbonates and hydrated ores, where water of hydration and other volatile impurities get removed. Calcination of carbonate ores gives out carbon dioxide. Hence, the ore is heated in absence of air. On the other hand, sulphide ores are generally roasted so that sulphur present as impurity in the ore is given out as sulphur dioxide. Hence, roasting is carried out in the presence of excess air.

Was this answer helpful?

Didn't liked the above answer ?

Text Generation Tool

💡 Some Related Questions

Metallurgy

Give reasons for the following pertaining to Hall Herault’s process.
(i) The fusion temperature of the electrolyte has to be lowered before conducting the electrolytic reduction.
(ii) The constituents of the electrolyte in addition to one part of fused alumina contains three parts of cryolite and one part of fluorspar.
(iii) A layer of powdered coke sprinkled over the electrolytic mixture, protects the carbon electrodes.
(iv) It is preferred to use a number of graphite electrodes as anode, instead of a single graphite electrode.

Open Answer »