METHOD OF SULPHURIC ACID DECOMPOSITION OF REM-CONTAINING PHOSPHATE RAW MATERIAL Russian patent published in 2015 - IPC C22B59/00 C22B3/08 

FIELD: chemistry.

SUBSTANCE: invention relates to method of obtaining compounds of rare earth metals (REM) in complex processing of phosphate raw material, in particular apatites. Claimed is method of sulphuric acid decomposition of REM-containing phosphate raw material with concentration of REM in phosphogypsum. Method includes addition of sodium salt, potassium salt or their mixture. Sodium salts are added in amount 0.25-5.0 kg in terms of Na₂O, potassium salts - in amount 0.25-5.0 kg in terms of K₂O, and their mixture - in amount 0.25-5.0 kg in terms of Na₂O and K₂O per 1 kg of REM in terms of REM oxides in composition of phosphate raw material.

EFFECT: increased degree of REM concentration in phosphogypsum due to increase of REM transition into phosphogypsum to 98%.

2 cl, 6 ex