The crystallization of sodium chloride is a very complicated process in evaporative crystallization of caustic soda which including multi-phase heat and mass transfer.

The research results showed that the modified film had good anti-corrosion performance in weak acid, neutral solution containing Cl- and strong alkali.

Double settling is used instead of double salting out, and less flocculant to replace large amounts of common salts required, thus the treatment of the waste is largely simplified.