METHOD OF SYNTHESIS OF FOOD DICALCIUM PHOSPHATE Russian patent published in 2000 - IPC

FIELD: inorganic chemistry, chemical technology. SUBSTANCE: invention relates to methods of wet-process phosphoric acid processing to obtain technical phosphates, in part, food dicalcium phosphate using waste production. Method of production of food dicalcium phosphate involves treatment of phosphogypsum with phosphate solution, filtration and drying the ready product. Process is carried out for two stages: at the first stage preliminary calcined phosphogypsum is treated with alkaline carbonate-containing reagent to pH 9.15-10; at the second stage obtained chalky pulp is mixed with preliminary purified wet-process phosphoric acid to pH 5.4-6. Invention ensures to enhance quality of ready product up to content of P₂O₅ 48.1-49% and decrease F content to 0.2%. EFFECT: decreased process duration, improved quality of product. 1 tbl, 3 ex