Question

Give the mond process for refining of nickel

Answer 1

1. Nickel oxide reacts with Syngas at 200 °C to give nickel, together with impurities including iron and cobalt.

NiO(s) + H2(g) → Ni(s) + H2O(g)

2. The impure nickel reacts with carbon monoxide at 50–60 °C to form the gas nickel carbonyl, leaving the impurities as solids.

Ni(s) + 4 CO(g) → Ni(CO)4(g)

3. The mixture of nickel carbonyl and Syngas is heated to 220–250 °C, resulting in decomposition back to nickel and carbon monoxide:

Ni(CO)4(g) → Ni(s) + 4 CO(g)

Steps 2 and 3 illustrate a chemical transport reaction, exploiting the properties that (1) carbon monoxide and nickel readily combine to give a volatile complex and (2) this complex degrades back to nickel and carbon monoxide at higher temperatures. The decomposition may be engineered to produce powder, but more commonly an existing substrate is coated with nickel. For example, nickel pellets are made by dropping small, hot pellets through the carbonyl gas; this deposits a layer of nickel onto the pellets.

Answer 2

The Mond process, sometimes known as the carbonyl process is a technique created by LudwigMond in 1890 to extract and purify nickel. This process makes use of the fact that carbon monoxide complexes with nickelreadily and reversibly to give nickel carbonyl.. The impure nickel reacts with carbon monoxide at 50–60 °C to form the gas nickel carbonyl, leaving the impurities as solids.