METHOD OF PROCESSING MONAZITE CONCENTRATE Russian patent published in 2015 - IPC C01F17/00 C22B3/04 C22B59/00 C22B60/00 

FIELD: chemistry.

SUBSTANCE: invention relates to rare and radioactive element technologies and can be used to obtain concentrates of rare and rare-earth elements from monazite. The method of processing monazite concentrate includes treating the feed stock with a mixture of sulphuric acid and ammonium fluoride at 200-230°C for 30-40 min, purifying the obtained product from phosphate and fluoride products by sublimation, water leaching sulphates of rare-earth elements, neutralising the solution with barium chloride, selectively separating the thorium, uranium, iron and rare-earth product, wherein separation of the rare-earth product is carried out through a step of precipitating double salts of rare-earth elements with ammonium sulphate, followed by conversion into nitrates of rare-earth elements through a calcination step, dissolving in nitric acid and solvent refining from thorium impurities.

EFFECT: invention provides high degree of extraction and purity of the rare-earth product.

3 cl, 2 dwg, 3 ex