METHOD OF ORGANIC EXTRAGENT REDUCTION Russian patent published in 2008 - IPC C01B25/46 

FIELD: chemistry.

SUBSTANCE: method of organic extragent reduction in production cycle of purified phosphoric acid production, including two-step washing of part of circulating extragent, which contains tributylphosphate, with its washing on the first stage with alkaline reagent and on the second stage - with water, removal of washing solution after each stage and mixing washing solution with phosphoric acid after the first stage. As alkaline reagent for washing of part of circulating extragent used are solutions of ammonium phosphates, which contain 2.5-10% P₂O₅, preliminary obtained by mixing ammonium and phosphoric acid, components being taken in amount ensuring mole ratio NH₃:P₂O₃=(6-8):1. To mixing with phosphoric acid ammonium water or gaseous ammonium are supplied. As phosphoric acid concentrated purified phosphoric acid or acid removed from re-extraction stage is used.

EFFECT: creation of efficient drainless method of organic extragent reduction in production of phosphoric acid aimed at optimization of by-product use in production of fertilizers and increase of amount of extragent which is taken out for reduction.

4 cl, 1 tbl, 4 ex