A metal extracted by any method is usually contaminated with some impurity. For obtaining metals of high purity, several techniques are used depending upon the differences in properties of the metal and the impurity. Some of them are listed below:

(a) Distillation

(b) Liquation

(c) Electrolysis

(d) Zone refining

(e) Vapour phase refining

(f) Chromatographic methods

Which of the following processes is used to purify lead?

Liquation

Metals that include impurities that are less flammable than the metals themselves—i.e., whose melting points are lower than the metals'—are purified using liquids. Liquation is a method of lead refinement.