Metal oxides are reduced to corresponding metals by using suitable reducing agents such as carbon. For example, when zinc oxide is heated with carbon, it is reduced to metallic zinc.

During the roasting of zinc ores, the chemical reaction involves the oxidation of zinc sulphide (ZnS) to zinc oxide (ZnO) and sulphur dioxide (SO2) gas. During the calcination of zinc carbonate ores, the chemical reaction involves the decomposition of zinc ...

Calcination is a process in which carbonate ores are heated strongly in limited air. During calcination, the carbonate ores are decomposed, releasing carbon dioxide gas and leaving behind metal oxides.

Roasting is a process in which sulphide ores are heated strongly in the presence of excess air. During roasting, the sulphide ores are oxidized, converting them into metal oxides.

It is easier to obtain a metal from its oxide rather than its sulphides or carbonates because oxides are more readily reduced to metals compared to sulphides and carbonates.