Lactic acid is a kind of organic acid which widely exists in nature.

Lactic acid is also called 2-hydroxypropionic acid. Lactic acid is a kind of organic acid which widely exists in nature. There are two corresponding isomers of lactic acid, namely D-lactic acid and L-lactic acid. D-lactic acid can be used as the synthesis precursor of a variety of chiral substances, as well as an important chiral intermediate and organic synthesis raw materials. It is widely used in the chiral synthesis of medicine, pesticide, cosmetics and many other fields.

At present, D-lactic acid is mainly produced by microbial fermentation. The crystallization acidolysis process of D-calcium lactate is a widely used separation and extraction process of D-lactic acid in industry. D-calcium lactate solution was obtained from fermentation liquor through alkalization, external filtration, concentration and cooling. D-lactic acid was obtained by acid hydrolysis, initial concentration, decoloration, ultrafiltration, ion exchange, concentration and evaporation.