Is fractional freezing a separation technique for mixtures?

Yes, fractional freezing, also known as zone refining, is a technique that can be used to separate components of a solution that have different melting points, just as distillation is a method of separating components of a solution that have different vapor pressures.

The component with the highest melting point in a liquid mixture will be the first to freeze, causing the liquid phase to concentrate more in the lower-melting component and the solid component to concentrate more in the higher-melting component.

Highly purified materials can be created by separating the liquid and solid phases and putting each through more cycles of freezing and melting.

A solid object, such as a rod, is passed through a heated zone in an enclosed system during the zone refining process. The heated zone creates a liquified layer that gradually permeates the material, concentrating the liquid in the low-melting impurity and eventually being removed when the melted zone reaches the end of the rod. This melting and freezing process is repeated until the required level of purity is reached.

Yes, fractional freezing is a separation technique for mixtures, particularly for separating components with different melting points. It involves gradually cooling a mixture to freeze one component while leaving the other components in the liquid state.