METHOD OF TREATING RARE-EARTH PHOSPHATE CONCENTRATE SEPARATED FROM APATITE Russian patent published in 2013 - IPC C01F17/00 C22B3/06 C22B59/00 

FIELD: chemistry.

SUBSTANCE: invention relates to methods of separating deactivated rare-earth elements during nitric acid treatment of apatite concentrate from nitrate-phosphate solutions. The method of treating a rare-earth phosphate concentrate isolated from apatite involves decomposition of the rare-earth phosphate concentrate with nitric acid, treating the obtained solution with oxalic acid with precipitation of rare-earth oxalates in two steps, at the first step of precipitation of oxalates of thorium and rare-earth elements, 5-10% oxalic acid in stoichiometric amount is added to rare-earth elements present in the solution, and at the second step of precipitation of rare-earth oxalates, 110-115% oxalic acid in stoichiometric amount is added to rare-earth elements present in the initial solution, and the rare-earth oxalates are then calcined to rare-earth oxides.

EFFECT: invention provides high economic efficiency of the process, which is achieved by avoiding the need to process and bury the precipitate containing thorium.

3 cl, 2 ex