Crystallization is the process used for the purification of solid substances. It is the process of formation of solid crystals of a substance precipitating from a homogeneous solution. Crystallization refers to the process of precipitating out the pure substance or compound from its solution or from an impure mixture by adding a suitable solvent to it. Crystallisation technique for purification is better than evaporation because:The extent of purification in case of crystallisation technique is very high.Crystallisation does not require very high-temperature conditions, there is no need to boil the solvent.In evaporation, we allow the solution to heat to make the solvent evaporate but this may degrade the solute into some another compound.The technique does not require complex apparatus setup for performing the purification.

Applications:

(i) In the pharmaceutical industry as a purification and separation process for the isolation and synthesis of pure active pharmaceutical ingredients.(ii) It's applied for large-scale productions like food additives.