METHOD OF PROCESSING MONAZITE Russian patent published in 2019 - IPC C22B59/00 C22B3/00 C22B1/06 

FIELD: technological processes.

SUBSTANCE: invention relates to the technology of rare and radioactive elements and can be used to produce concentrates of rare and rare-earth elements from monazite, including monazite concentrate stored in Krasnoufimsk. Monazite processing involves hydrofluorination with ammonium bifluoride, sulphatization with sulfuric acid and aqueous leaching of sulphates. During hydrofluorination and sulphatization processes, the formed products are ground to 1–25 mcm. Hydrofluorination is carried out with ammonium bifluoride in amount of 80–90 % of stoichiometrically required, sulphatization is carried out with 94–96 % sulfuric acid, taken with excess of up to 30 % of stoichiometrically required. Leaching is carried out at water temperature of up to 20 °C.

EFFECT: method enables separation of rare-earth elements from thorium, separating them by 99 % into a liquid phase in form of sulphates and leaving up to 97,3 % of thorium, 90,1 % of iron, 99,6 % of titanium and 79,8 % of phosphorus in form of fluoride and pyrophosphate of thorium, pyrophosphate of titanium and iron phosphate in undissolved residue.

1 cl, 4 ex