Solvent extraction of uranium from acidic sulfate media by Alamine® 336: computer simulation and optimization of the flow‐sheets

BACKGROUND: A series of nine conventional and non‐conventional flow‐sheets have been considered for the recovery of uranium from acidic sulfate solution by liquid–liquid extraction with 0.146 mol L^?1 Alamine^® 336 in kerosene modified with 5% w/w 1‐tridecanol and stripping with a 199 g L^?1 Na₂CO₃ solution. The reference flow‐sheet was a classical counter‐current configuration with four mixers–settlers in the extraction stage and three mixers–settlers in the stripping stage. The others flow‐sheets possessing a total of eight mixers–settlers are unusual combined solvent extraction flow‐sheets with one or two independent extraction stripping loops and with one or two feed inlets. RESULTS: The configuration of the flow‐sheets strongly influences the extraction performance of the process depending on the working conditions (feed, stripping and solvent flow rates). The presence of two independent extraction–stripping loops may allow the delay of the saturation phenomenon encountered in the conventional flow‐sheet and thus, to operate at higher feed flow rates without loss of performance, as far as the residual fraction in the raffinate and the concentration factor in the stripping solution are concerned. Furthermore, the presence of a modification in the non‐conventional flow‐sheets with two independent extraction–stripping loops and two feed inlets leads to interesting configurations for uranium recovery from less concentrated solutions, such as heap leach solutions. CONCLUSION: The use of non‐conventional flow‐sheets is interesting as it allows the process of uranium (VI) recovery by liquid–liquid extraction to be improved. Copyright © 2009 Society of Chemical Industry