Question

Give reason: Carbonate and sulfide ores are usually converted into oxides during process of extraction.

Answer 1

Roasting

• Sulfide ores are converted into oxides by heating in presence of excess air called as Roasting.
• Sulfide ores due to easily conversion of their oxides in presence of excess air, they are generally roasted.

$\underset{\mathrm{Copper}\mathrm{Sulphide}}{2{\mathrm{Cu}}_2\mathrm{S}\left(\mathrm{s}\right)}+\underset{\mathrm{Dioxygen}}{3{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Copper}\mathrm{oxide}}{2{\mathrm{Cu}}_2\mathrm{O}\left(\mathrm{s}\right)}+\underset{\mathrm{Sulfur}\mathrm{Dioxide}}{2{\mathrm{SO}}_2\left(\mathrm{g}\right)}$

Calcination

• Carbonates are changed into oxides by strongly heating them in limited air called as Calcination.
• Calcination reactions usually take place at or above the thermal decomposition temperature or the transition temperature.
• Chemical Reaction involved:

$\underset{\mathrm{Calcium}\mathrm{carbonate}}{{\mathrm{CaCO}}_3\left(\mathrm{s}\right)}\to \underset{\mathrm{Calcium}\mathrm{Oxide}}{\mathrm{CaO}\left(\mathrm{s}\right)}+\underset{\mathrm{Carbon}\mathrm{Dioxide}}{{\mathrm{CO}}_2\left(\mathrm{g}\right)}$

• Carbonate and sulfide ores are usually converted into oxides during extraction because it is much easier from their oxides rather than from their carbonates or Sulfides.

Therefore, due to formation of its oxides it is much easier to extract carbonate and sulfide ores.