Solvent Extraction of Thorium with Versatic 911

The distribution of Th(IV) between an aqueous solution and a high-molecular weight synthetic carboxylic acid, Versatic 911 (Shell Co. Ltd., London), diluted with benzene was studied. Thorium was quantitatively extracted at pH 4.0-4.9 from 0.1 M acetic acid solution. The study of the effects of pH, extractant concentration, metal concentration, diluent, and contact time on the extraction of thorium(IV) was performed. The metal/Versatic 911 ratio was determined in the extracted species and the experimente showed that the ratio is 1:4. The extraction dependence upon acetate ion concentration was also examined. Thorium(IV) was separated from magnesium, calcium, strontium, barium, manganese, cobalt, nickel, zinc, cadmium, lanthanum, praseodymium, neodymium, samarium, gadolinium, and mercury. The proposed methods are very simple, rapid, and fairly selective, and can be carried out both at micro and macro levels. Important quantitative separations of thorium from synthetic mixtures were also carried out.