METHOD OF PROCESSING RARE-EARTH ELEMENTS CONCENTRATE

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FIELD : chemistry. SUBSTANCE : invention relates to chemical technology of producing compounds of rare-earth elements (REE) during complex processing of apatites and can be used in extraction and concentration of REE. Phosphate raw material is decomposed with nitric acid. REE and impurities of aluminium, iron, calcium, silicon, titanium, thorium are sorption-extracted. Then their desorption is performed without thorium, silicon, titanium. REE concentrate is deposited from the strippant with an ammonia-containing component. Concentrate is decomposed with 58 % nitric acid. Extraction purification of the obtained solution is performed with tributyl phosphate (TBP) in presence of salting-out agents in the counterflow mode. Extract is washed, re-extraction is performed and the extractant is regenerated. Herewith the concentrate is decomposed at a temperature not more than 30 °C for not more than 30 minutes. Solution not containing thorium, silicon, titanium is fed for the cleaning extraction. As the salting-out agents ammonium and aluminium nitrates are used, which are parts of the purified solution in the weight ratio of (11÷25) : 1 with the total content of 550-650 g/l. EFFECT : reducing power consumption, reducing consumption of reagents, elimination of additional operations, reducing process duration, reducing the number of extraction steps. 1 cl, 3 tbl