METHOD OF PURIFICATION OF THE EXTRACTIVE PHOSPHORIC ACID Russian patent published in 2006 - IPC C01B25/46 C01B25/234 

FIELD: chemical industry; methods of purification of the extractive phosphoric acid.

SUBSTANCE: the invention is pertaining to the method of purification of the extractive phosphoric acid by the organic extractants and production of the phosphoric acid with the low content of impurities, that allows to use it in production of the phosphoric of the industrial and alimentary qualities. In particular, the invention is pertaining to purification of the extractive phosphoric acid containing the significant amount of ions of magnesium. The method includes extraction of the phosphoric acid by tributyl phosphate, washing of the produced extract by the phosphate solution and the subsequent reextraction with production of the reextract and after that its evaporation by the purified phosphoric acid. The extraction is conducted using 4-5 stages, and for washing they feed the phosphate solution in the amount providing the ratio P₂O₅:Mg in the extract equal to (5-8 : 1). As the phosphate solution of washing use either a part of the reextract, or the purified water diluted phosphoric acid. The technical result of the invention consists in purification of the phosphoric acid containing a significant amount of magnesium, at simultaneous increase of extraction of P₂О₅.

EFFECT: the invention ensures purification of the phosphoric acid containing a significant amount of magnesium, at simultaneous increase of extraction of P₂О₅.

2 cl, 1 ex