METHOD OF SODIUM PHOSPHATE SALTS MIXTURE PRODUCING Russian patent published in 1998 - IPC

FIELD: chemical technology, inorganic chemistry. SUBSTANCE: method involves neutralization of phosphoric acid with sodium hydroxide or soda to mole ratio Na₂O : P₂O₅ = 1.55-1.67, separation of impurities from solution and feeding the latter for dehydration. Firstly, phosphoric acid is neutralized to complete ratio Na₂O : P₂O₅ = 1.9-2.5 followed by additional neutralization of solution. Solution at density 1.40-1.51 is fed to dehydration. Dehydration is carried out preferably for either one stage at temperature of exhausting gases 220-270 C or for two stages at temperatures 150-200 C and 240-270 C, respectively. The end product is used in chemical and food industries. EFFECT: improved method of producing. 2 cl, 1 tbl