There are three main methods of recovering and purifying nickel from ore in industry.
1. Electrolysis method:
The enriched sulfide ore is calcined into oxide and reduced by fire to obtain metallic nickel and cast into nickel anode. After electrolysis, high purity nickel is obtained at cathode.
2. Chemical reduction method:
The nickel oxide ore is chemically leached, the co-existing elements are separated, the pure nickel oxide is obtained, and then hydrogen is used to reduce the nickel oxide at a certain pressure and temperature to obtain the metallic nickel.
3. Carbonylation method:
The sulfide ore of nickel reacts with CO to form the volatile nickel tetracarbonyl Ni(CO)4, which is decomposed into CO and nickel by heating, and nickel with high purity can be obtained.