(A) Calcination For hydrated carbonate or bicarbonate ores \(\Rightarrow(4)\) malachite, \(\mathrm{CuCO}_3 \cdot \mathrm{Cu}(\mathrm{OH})_2\)
(B) Roasting For sulphide ores \(\Rightarrow\) (1) galena, \(\mathrm{PbS}\)
(C) Magnetic separation For magnetic ore or gangue \(\Rightarrow\) (2) magnetite, \(\mathrm{Fe}_3 \mathrm{O}_4\)
(D) Carbon reduction of metal oxide It is done is furnaces on application of heat \(\Rightarrow\) (3) pyrometallurgy
The correct matching is (A)-(4), (B)-(1), (C)-(2), (D)-(3)