Question

The method used in metallurgy to refine the impure metal is:
A. Mond process
B. Van Arkell process
C. Liquidation
D. All of the above

Answer 1

We know that refining in metallurgy is the process in which we purify an impure metal. Refining of the impure metals increases the grade and purity of the metal. There are different processes by which we can refine impure metals . Some of the processes are distillation, zone refining, vapour phase refining, electrolytic refining and many more.

Complete step by step solution:
As we know that in vapour phase refining the metal is converted into its volatile compound and then again decomposing it to obtain the pure metal. Mond process and Van Arkell process are different types of vapour phase refining process. Mond process is used to purify the Nickel metal with the help of carbon monoxide. For this reason , it is also known as the carbonyl process. The Mond process is:
$Ni + 4CO\xrightarrow{{330 - 350K}}Ni{(CO)_4} \\\ Ni{(CO)_4}\xrightarrow{{450K - 470K}}Ni + 4CO \\\$
The Van Arkell method is used to purify metals like Titanium and Zirconium with the help of iodine. The example of Van Arkell method is:
$Ti + 2{I_2}\xrightarrow{{500K}}Ti{I_4} \\\ Ti{I_4}\xrightarrow{{1700K}}Ti + 2{I_2} \\\$
Liquation is a refining process in which the principle of partial melting is used. The metal is heated in such a way that one of the constituents melts and the other remains solid, after this the liquid constituent is drained off. The process of refining is used to refine the metals like antinomy ,silver and copper lead as a solvent.
From the above explanation it is clear to us that the Mond process, Van Arkell process and Liquidation are refining methods used in metallurgy.

So the correct answer to the question is: D. All of the above.

Additional information:
It is important to know that the principle used in the zone refining method is that the impurities are more soluble in the molten state as compared to the solid state of the metal. Zone refining is used to refine metals like germanium, silicon, boron and gallium. It includes mainly the semiconductor elements.

Note: Always remember that Mond process and Van Arkell method comes under vapour phase refining. Mond process is used to purify nickel and the van arkel method is used to purify metals like titanium and zirconium. Liquation is a type of refining which is used to purify metals like antinomy, silver and copper.