Statistical study of factors affecting the co-extraction of uranium and iron in the second cycle of extraction with DEHPA/TOPO in kerosene

The co-extraction of uranium and iron with di-(2-ethylhexyl) phosphoric acid (DEHPA)/tri-n-octyl phosphine oxide (TOPO) in kerosene from loaded phosphoric acid in the second extraction cycle is influenced by the factors uranium, iron, DEHPA concentration, P2O5% and organic-to-acid ratio (O/A). From a general regression equation, two mathematical models have been generated representing the effect of these five factors on the selectivity and yield: the interaction between factors has been ascertained. Analysis and interpretation of the results enabled us to determine the best experimental operating conditions of the second extraction cycle to obtain a least contaminated loaded solvent and to improve the quality of the yellow cake.