Which refining process is generally used in the purification of low melting metals?

Liquification of liquation: In this method a low melting metal like tin can be made to flow on a sloping surface. In this way it is separated from higher melting impurities.

This process is used for the purification of the metal in which melting point of the metal to be purified should be lower than that of each of the impurities associated with the metal. This process is used for the purification of $\mathrm{Sn}$ and $\mathrm{Zn},$ and for removing $\mathrm{Pb}$ from $\mathrm{Zn}-\mathrm{Ag}$ alloy.