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

FIELD: processes of water preparation to avoid formation and removal of deposit. SUBSTANCE: method comprises neutralization of phosphoric acid with calcined and caustic soda, addition to partially or completely neutralized solutions of trisodium phosphate crystallization modifier which is mixture of sodium tripolyphosphate and pyrophosphate at ratios thereof of 0.5-4:1 in amount of 0.002-0.014 per 1 part of final product, cooling of solution to crystallize trisodium phosphate dodecahydrate and to separate it from mother liquor. EFFECT: no drying stage, lower water repelling properties and reduced caking power of the product and reduced content of sulfate impurities in the product from 0.6-0.8 to 0.1-0.3%. 3 cl, 3 ex, 1 tbl