METHOD FOR EXTRACTION OF RARE EARTH METALS FROM SEMIHYDRATE PHOSPHOGYPSUM Russian patent published in 2022 - IPC C22B3/08 C22B59/00 

FIELD: chemical industry.

SUBSTANCE: invention relates to the chemical industry, in particular to the technology of extraction of rare earth metals (REM) from phosphogypsum (PG) obtained by semi-hydrate processing technology of apatite concentrate. Phosphogypsum is pretreated, leached with a solution of sulfuric acid, sorption of rare earth metals from a solution using ionite with sulfonic acid functional groups, followed by desorption with an ammonium sulfate solution. The concentrate of rare earth metals is precipitated with carbonic acid salts. At the stage of pretreatment, semihydrate phosphogypsum is soaked in water at a ratio of phosphogypsum and water (S:L) 1:0.6-1.0 without stirring for 2-7 days. Then they are crushed to a size of 1-3 cm and the water-soluble impurities are washed with water in the repulping mode at a ratio of phosphogypsum and water (S:L) 1:1.5-2.0.

EFFECT: method simplifies the technology of processing semihydrate PG, increases the degree of extraction of REM from semihydrate PG while simultaneously improving the quality of rare earth concentrate.

1 cl, 3 dwg, 8 tbl