This technique fractionates via differences in crystallization temperature and enables the purification of multi-component mixtures, as long as none of the constituents can act as solvents to the others.

This is the fundamental physical principle behind the melt fractionating process and quite comparable to distillation, which operates between a liquid and the gas phase.

In practice, various strategies such as partial melting of the solid fraction (sweating) need to be applied in order to reach high purity levels.

This arrangement allows for reproducible and high transfer rates of heat, facilitating the growth of crystals from the falling film of melt.

Examples of applications include isopulegol, phosphoric acid, wax and paraffins, anthracene / carbazole and even satellite-grade hydrazine.

This method is more complex to operate, but offers the advantage of a high separation efficiency, which translates to considerable engery savings.