An ore gives Carbon dioxide on treatment with HCL . Outline the steps to be taken to convert this ore into free metal ?

If an ore on treatment with dilute hydrochloric acid releases brisk effervescence of a colourless and odourless gas. Then the ore should be a carbonate ore. As only metal carbonates on treatment with dilute hydrochloric acid releases carbon dioxide a colourless and odourless gas with brisk effervescence. Hence carbonate ores are converted to their metal oxides by calcination process.

Heating of carbonate ores in the limited supply of air to convert them into oxides is known as calcination. Carbonate ores are calcined to drive out carbonate and moisture impurities and are converted to their respective oxides.

E.g.

ZnCO3(s)----------> ZnO(s) + CO2(g)

Al2O3.2H2O -------------> Al2O3(s) + 2H2O(l)