There are many ways to crystallize in crystallizer, not only evaporative crystallization, but also cooling crystallization, heating crystallization, reaction crystallization and salting-out crystallization. As we all know, the solution that needs crystallization must be saturated to produce crystallization, so these methods are all ways to make the solution saturated.

　　1. Evaporative crystallization
　　The solution is evaporated by heating at atmospheric or vacuum pressure, and some solvents are evaporated to concentrate the solution to supersaturation to precipitate crystals. This method is called evaporative crystallization. Evaporative crystallization can be divided into three types: atmospheric evaporative crystallization, vacuum evaporative crystallization and azeotropic vacuum crystallization.
　　2. Cooling crystallization
　　Crystallization by freezing is the method of precipitating crystals by lowering the temperature to make the solution supersaturated. This method is suitable for substances whose solubility decreases significantly with the decrease of temperature.
　　3. Warming Crystallization

　　Raising temperature can also make some solutions supersaturated and crystallize. This method is suitable for substances whose solubility decreases significantly with increasing temperature.
　　4. Reactive crystallization
　　Adding some chemicals or adjusting PH to change the chemical composition and properties of the solute from soluble state to insoluble state, so as to achieve supersaturation and precipitate crystals.
　　5. Salting-out Crystallization
　　There are two ways to achieve supersaturated Precipitation Crystallization by adding another substance to reduce the solubility of solute in solution.
　　1 Addition of a solute, called salting-out agent, reduces the solubility of another solute in the solution to supersaturation.

　　2. Adding another solvent, the solute in the solution can be supersaturated and crystallized.