ORGANIC EXTRACTANT RESTORATION PROCESS IN PURIFIED PHOSPHORIC ACID PRODUCTION Russian patent published in 2003 - IPC

FIELD: industrial inorganic synthesis. SUBSTANCE: invention relates to production of pure phosphoric acid from extraction phosphoric acid by treating it with organic solvent, preferably water-immiscible solvent. Process comprises two-step mixing of organic phase containing tributyl phosphate or diluted tributyl phosphate with (i) alkaline solution at organic phase-to-aqueous phase ratio (1-4):1 and 20-60 C and (ii) with water, resulting mixtures being separated and wash solutions removed from the process. Process is effect in one apparatus in pulsation mode with countercurrent supply of reagents. First-step pulsation ranges from 0.2 to 1 cm/s and, in the second step, 0.5 to 2 cm/s. EFFECT: increased degree of purification, simplified process, enhanced rinsing reagent use efficiency, and reduced loss of extractant. 3 cl, 1 tbl