General Principles and Processes of Isolation of Elements
Give the steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores.
Solution: During extraction of metals of low and medium reactivity, a respective sulphide ore is first heated in air. This helps in obtaining oxide of metal. It is easier to extract a metal from its oxide rather than from its sulphide. Hence, this step is used. Mercury is a metal of low reactivity.
Mercury sulphide (cinnabar) is heated in air. Mercury sulphide gets oxidized to produce mercury oxide.
After that, mercury oxide is reduced to obtain mercury.
Zinc is a metal of medium reactivity. It is found as zinc blende (ZnS).
Zinc blende is roasted to be converted into zinc oxide. Zinc spar is put under calcination to be converted into zinc oxide.
Zinc oxide so obtained is reduced to zinc metal by heating with carbon (a reducing agent).