ABSTRACT
Evaporation and distillation are similar processes in that a liquid is vaporized, and the vapor is usually condensed to recover a liquid of different composition. The distinguishing feature between them is that in evaporation the material left behind is non-volatile. In distillation, all components of the feed may be at least slightly volatile and require further separation. Thus, evaporation is used to remove volatile solvents, usually water, from non-volatile impurities. Such nonvolatile impurities may be inorganic salts, heavy tars and sludges, or radioactive wastes. Evaporation leaves behind either a thickened slurry of solids, a viscous non-volatile liquid, or a dry solid product.
