Chemistry
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
19 Likes
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.
Answered By
12 Likes
Related Questions
Give reasons for the following:
Magnetic separation is not used during the dressing of bauxite ore in the extraction of aluminium.Give reasons for the following:
Conversion of concentrated ore to it's oxide is an essential step in the extraction of metals from the ore, even then the step is not necessary in the metallurgy of aluminium.Give reasons for the following:
Roasting the ore generally results in evolution of sulphur dioxide gas, while calcination of the ore evolves carbon dioxide gas.Give reasons for the following:
Reduction of metallic oxides to metal in the extraction of metals from the ores is based on the position of the metal in the activity series.