METHOD OF PROCESSING PHOSPHOGYPSUM FOR PRODUCTION OF CONCENTRATE OF RARE EARTH METALS AND GYPSUM Russian patent published in 2014 - IPC C22B59/00 C22B3/08 C22B3/24 

FIELD: chemistry.

SUBSTANCE: method includes preparation of phosphogypsum pulp, leaching rare earth metals (REM) and phosphorus with sulphuric acid. After that, pulp is separated into REM and a phosphorus-containing solution and gypsum in the form of insoluble sediment, its neutralisation and REM sorption with cationite from the solution with obtaining mother liquor. After that, REM desorption is performed with obtaining a strippant and separation of REM concentrate from the strippant. Stage leaching is performed in the method, with supply of phosphogypsum to each stage and sulphuric acid to the first stage. Before neutralisation gypsum is subjected to water washing with obtaining a washing solution, supplied to REM sorption with cationite. Sorption mother liquor is divided into two parts, one of which is used to prepare phosphogypsum pulp, with precipitation of phosphorus and fluorine with basic calcium compound from the second one. The obtained sediment is separated from water phase and supplied to utilisation, and water phase is used in circulation.

EFFECT: increased degree of REM extraction from phosphogypsum, reduction of specific costs of chemical reagents with provision of in fact complete water circulation and obtaining gypsum of the required quality by phosphorus and fluorine.

14 cl, 1 dwg, 3 ex