Question

What is liquation?

Answer 1

Metals when extracted from any source have impurities and liquation is one of the refining techniques in which a low melting metal is made to flow on a sloping surface and this helps in separating from high melting impurities.

Complete step by step answer
Any metal extracted from any method is usually contaminated with impurities. So, to obtain metal of high purity we have refining techniques depending upon the differences in the properties of the metal and impurity and liquation is one such refining technique. Liquation is based on the difference in the melting point of the metal to be extracted and the impurity. Firstly, the material is heated on a sloppy surface until one starts to melt and drain away from the other which is then collected in a separate container. Also this process is $100\%$efficient as it involves no loss of metal. This method was largely used to remove lead containing silver from copper, but it can also be used to remove antimony minerals from ore, and refine tin.

Note
There are other refining techniques also which are distillation, electrolysis, zone refining, vapor phase refining and chromatographic methods which involve different principles for the separation of metal from impurities. Distillation is based on the boiling point of the metals, in electrolytic refining the impure metal is made to act as anode and the pure metal is made as cathode and then electricity is passed through them. In case zone refining it is based on the principle that impurities are more soluble in the melt than in the solid state of the metal. And in case of vapor phase refining the metal is first converted into a volatile compound and then decomposed to give pure metal.