<Purification of Solid Crystals>

1.Recystalization method   
We can do recystalization operation at-75deg. 

2.Sublimation method
Applicable for Mass production or Multi-step
sublimation system.  
We can combine both methods of distillation
and sublimation.
 
3.Flaker method
We can selectively make up pure flake
by choosing solvent.   
This method has lots of advantages against
recrystalization system.
This method will be applied for batch or
continuous production system.