METHOD OF SYNTHESIS OF TRISODIUM PHOSPHATE Russian patent published in 2000 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention relates to method of synthesis of trisodium phosphate that is used as water softener, inhibitor of salt deposition, component of detergents. Method involves neutralization of 30-47% solutions of sodium hydroxide with wet-process phosphoric acid in the mass part of P₂O₅ 37-56% in the presence of mother liquid of trisodium phosphate in the mass part of trisodium phosphate 6-10%, at 85-95 C up to pH of medium 11.5-12.5 followed by filtration of reaction mixture from impurities at 70-80 C, cooling mother liquid to 0-20 C, crystallization of trisodium phosphate, separation of product by filtration or centrifugation and recovery of mother liquor of trisodium phosphate to the synthesis stage. EFFECT: minimal content of impurities in trisodium phosphate. 4 ex