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

FIELD: technology of inorganic matter, more particularly water preparation processes. SUBSTANCE: method comprises neutralizing phosphoric acid at 70-100 C with calcined soda, separating impurity components, coating the solution to 30-35 C and crystallizing trisodium phosphate duodeca hydrate in the presence of conditioning additive such as alkali metal orthophosphates having specific surface of 0.5-2.0 sqm/g (amount of said orthophosphates is used with 0.0005-0.0025 mole of oxides of corresponding metals per 100 wt parts of precipitate) and separating the latter from mother liquor. If extraction phosphoric acid is to be processed, predetermined amount and quality of alkali metal orthophosphates are attained due to neutralization of phosphoric acid with calcined soda to Na₂O:P₂O₅ molar ratio of 5:3 and subsequent separation of impurity components. EFFECT: cheaper technological process and reduced expenses for preparation of the desired product. 2 ex, tbl