METHOD FOR EXTRACTION OF LANTHANIDES FROM EXTRACTIVE PHOSPHOROUS ACID Russian patent published in 2010 - IPC C01F17/00 C01B25/237 

FIELD: technological processes.

SUBSTANCE: invention may be used in chemical technology for production of rare earth elements. To return phosphorous acid with concentration of 31.0-38.5 wt %, containing compounds of rare earth elements, at 65-80°C, solution of sodium carbonate is added in amount, which provides for its content in purified phosphorous acid of 5-10 g/l on the basis of Na₂O. Produced residue of sodium hexafluosilicate is separated from purified phosphorous acid, sulfuric acid is introduced in it to provide for its concentration of 10-15 wt %, and produced mixture of acids is maintained for at least 1 hour with production of residue of double lanthanides and sodium sulfates. Residue is separated from acid solution and is washed with sulfuric acid with concentration of at least 36%. As sodium compound, sulfate or chloride may also be used. Method is compatible with dihydrate technology of apatite concentrate processing. Extent of lanthanides extraction into concentrate achieves 87.7%.

EFFECT: invention makes it possible to produce concentrate of rare earth metals in easily processed sulfate form and to reduce energy intensity of the process.

7 cl, 4 ex