METHOD OF EXTRACTING RARE EARTH ELEMENTS FROM EXTRACTION PHOSPHORIC ACID Russian patent published in 2015 - IPC C22B59/00 C22B3/24 C01F17/00 

FIELD: chemistry.

SUBSTANCE: invention relates to a method of extracting rare earth elements (REE) from extraction phosphoric acid (EFA). The method includes the application of an anionite of a phosphate-mixed form in a cyclic process of sorption-desorption. Desorption at all, except the last, stages-cycles is carried out until a ratio of initial (C₀) and final (C) concentrations of the acid corresponds to the condition 0.25≤C/C₀≤0.75, and at the last one until the concentration of desorbed phosphoric acid is not more than 0.15 mol/l. Passing of EFA through a column with an anionite is carried out at each stage of the cycle from bottom to top to a breakthrough, corresponding to a relative concentration, corresponding to the condition 0.25≤C/C₀≤0.75. An obtained enriched in REE solution is directed to the extraction of a solid REE concentrate. Desorption at each stage of the cycle is carried out with diluted phosphoric acid with obtaining at all, except the last one, stages-cycles of a purified phosphoric acid desorbate and a last stage-cycle desorbate - with a relative concentration of phosphoric acid, corresponding to the condition 0.25≤C/C₀≤0.75, and with the concentration lower than 0.25 mol/l. The latter is returned to the desorption stage.

EFFECT: increased extraction of the REE concentrate.

7 cl, 8 dwg, 4 tbl, 6 ex