(A) Calcination For hydrated carbonate or bicarbonate ores ⇒(4)
malachite, CuCO3⋅Cu(OH)2
(B) Roasting For sulphide ores ⇒(1) galena, PbS
(C) Magnetic separation For magnetic ore or gangue ⇒(2) magnetite, Fe3O4
(D) Carbon reduction of metal oxide It is done is furnaces on application
of heat ⇒(3) pyrometallurgy
The correct matching is (A)−(4),(B)−(1),(C)−(2),(D)−(3)