METHOD FOR PRODUCING SODIUM TRIPOLYPHOSPHATE Russian patent published in 1998 - IPC

FIELD: chemical industry; production of phosphoric salts, in particular, sodium tripolyphosphate used in detergent compositions, in agents for combatting front formation, as fodder and alimentary additive, etc. SUBSTANCE: starting material is subjected to in-depth defluorination by neutralization with soda up to pH=0.7-2.5. After separating precipitate, filtrate is subjected to desulphurization treatment with barium compounds taken in such amount as to meet weight ratio BaO-to-CaO=0.2:0.4. Slurry is successively neutralized with soda to achieve molar ratio 1.05-1.08 and 1.63-1.65 at temperature 80-85 C, each neutralization step lasting 2-2.5 h. EFFECT: new approach to sodium tripolyphosphate production. 1 tbl