PROCESS FOR PRODUCING A PURIFIED SOLUTION OF PHOSPHORIC ACID AND / OR DICALCIUM PHOSPHATE SALTS

Abstract

The invention relates to a process for producing a purified phosphoric acid solution and / or dicalcium phosphate salts.A process for producing a purified phosphoric acid solution (31, 33) includes the steps of (a) providing a mineral source of phosphate (1); (b) carrying out an acid attack on the mineral source of phosphate with a concentrated aqueous solution of a strong acid (3) to obtain an attack mixture (5); (c) diluting the attack mixture in water (7) to obtain a monocalcium phosphate solution (11); (d) filtering, (e) acidifying with a strong acid (19) to obtain a phosphoric acid solution (21); (f) optionally pre-purify to obtain a pre-purified phosphoric acid solution (25) and (g) separate through a membrane (29) the phosphoric acid solution (21, 25) to recover a purified phosphoric acid solution (31), the membrane (29) being selected from a diffusion dialysis acid separation membrane, an electrodialysis-driven depletion membrane or a nanofiltration membrane.The invention also relates to a process for producing a dicalcium phosphate salt (47, 49). (Fig. 1).