METHOD OF PURIFYING EXTRACTION PHOSPHORIC ACID Russian patent published in 2001 - IPC

FIELD: processing of mineral phosphate stock, more particularly purification of extraction phosphoric acid used in chemical industry. SUBSTANCE: phosphoric acid is extracted with organic solvent when adding bases of monovalent cations such as sodium potassium, ammonium and derivatives thereof or salts thereof with phosphoric acid at molar ratio of monovalent cation being added to sulfate-ion in original phosphoric acid of 0.5-10, at phosphoric acid concentration in aqueous phase of 1.5- 10.5 mole/g, and extract is optionally washed with aqueous solution of the same substances. Organic solvents are preferably ketones and ethers, e.g. tributyl phosphate in pure form of with addition of polar diluent. Method makes it possible to carry out more effectively purification of phosphoric acid to remove sulfuric acid. EFFECT: more efficient purification method. 2 cl, 1 dwg, 44 ex, 5 tbl