<unk>  is a process used in process engineering and chemistry to separate two liquids with different melting points. It can be done by partial melting of a solid, for example in zone refining of silicon or metals, or by partial crystallization of a liquid, for example "freeze distillation", also called "normal<unk> " or "progressive<unk> ".  Partial crystallization can also be achieved by adding a diluent solvent to the mixture, and cooling and concentrating the mixture by evaporating the solvent, a process called "solution crystallization".<unk>  is generally used to produce ultra-pure solids, or to concentrate heat-sensitive liquids.
Fractional freezing
Transfusion therapy
Dialysis
Chelation therapy
VAD regimen
ClaPD regimen
Lethal injection
Exchange transfusion