METHOD OF PROCESSING CHEMICAL CONCENTRATE OF NATURAL URANIUM Russian patent published in 2013 - IPC C22B60/02 C22B3/38 

FIELD: chemistry.

SUBSTANCE: method involves dissolving a chemical concentrate of natural uranium in nitric acid solution, extracting and re-extracting uranium. The dissolved concentrate contains 1.2-3.7 wt % iron to uranium, 1.4-4.0 wt % sulphur to uranuim and 0-0.7 wt % phosphorus to uranium in nitric acid solution. Nitric acid and water are taken in an amount which provides the following concentration in the solution fed for extraction: uranium 450-480 g/l, iron (III) ions 0.1-0.3 mol/l, sulphate ions 0.2-0.6 mol/l, phosphate ions 0-0.10 mol/l, and free nitric acid 0.8-2.4 mol/l, and saturation of extractant with uranium during extraction is maintained in accordance with the ratio: Y ≤90.691-34.316·[SO₄]+7.611·([Fe]-[PO₄])+5.887·[HNO₃]-9.921·[SO₄]·[HNO₃]+19.841·[SO₄]²+7.481·([Fe]-[PO₄])·[HNO₃]-64.728·([Fe]-[PO₄])·[SO₄]+92.701·[SO₄]·[HNO₃]·([Fe]-[PO₄])-185.402·[SO₄]²·([Fe]-[PO₄]), where Y is saturation of the extractant with uranium, %, and concentration in the solution fed for extraction, mol/l: [SO₄] - sulphate ions, [PO₄] - phosphate ions, [HNO₃] - nitric acid, [Fe] - iron (III) ions.

EFFECT: obtaining raffinates with low uranium content.

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