Uranium extraction from sulphuric acid leach liquor by Cyanex®272 as intermediate in nuclear fuel cell

Abstract

The uranium extraction from sulphate pregnant solution by Cyanex (R) 272 in kerosene diluent was examined. The influence of parameters affecting the extraction mechanism including Cyanex (R) 272 concentrations and equilibrium pH was investigated. At optimized conditions, the extraction efficiency of 97.1 +/- 3% U(VI) by 0.3 mol/L Cyanex (R) 272 at 27 +/- 2 degrees C in the equilibrium pH range of 3-4 was achieved from the pregnant solution containing admixtures of 3596.3 mg/L U(VI), 31.47 mg/L Th(IV), 11.01 mg/L Fe( III), 68.70 mg/L Al(III), 7.29 mg/L Mn(II), 0.57 mg/L Ce(IV), 0.49 mg/L La(III), and 0.10 mg/L Pr( IV), respectively. Maximum stripping of U(VI) from the loaded organic phase was achieved using 0.5 mol/L Na2CO3 solution. Finally, uranium from uranyl solution recovered as sodium diuranate ( Na2U2O7: 00-064-0473, density = 6.51 g/ cm(3), melting point = 1654 +/- 2 degrees C) is capable of serving as an intermediate in a nuclear fuel cell.