Computer study of uranium extraction from phosphoric acid at various organic flow arrangements

Simulation of the first cycle of the DEPA-TOPO process of uranium recovery from wet-process phosphoric acid with mixer-settler contactors operated in a counter-current (CTC), cross-current (CSC) and an alternative extraction- stripping (AES) flow arrangement (FA) was done. The simulation was performe d for the cases when the equilibrium relationships are linear in the extrac tion and stripping section as well as non-linear in the stripping section. In order to get the equilibrium relationships, the DEPA-TOPO process was si mulated in separation funnels using representative phosphoric acid samples taken from a fertilizer company. The Murphree stage efficiencies (for the e xtraction section for the aqueous phase, EMx, and for the stripping section EMx(s)) were taken into account in the model. As far as the recovery is concerned, CSCFA is better than other FAs. The sa me number of stages in the extraction and the stripping section is better t han other combinations if the total number of stages is constant. For the C TCFA, there is an optimum of the organic-to-aqueous flow rate. This value d epends on the extraction and stripping isotherms slopes (E and E-s coeffici ents, EMx and EMx(s) stage efficiencies, and, in the case of non-linear str ipping isotherm, on the inlet uranium concentration).