Solvent Extraction Of Cadmium From Sulphate Solutions Using Sodium Salts Of Tops -99, PC -88A, Cyanex -272 And Their Mixtures

摘要

Solvent extraction studies of cadmium have been carried out from 0.1 M sulphate solutions using the sodium salts of TOPS-99, PC-88A and Cyanex-272 diluted in kerosene. Percentage extraction of cadmium increases with increasing equilibrium pH of the aqueous phase and extractant concentration. The species extracted into the organic phase appears to be associated with 3 moles of the extractant. Loading capacity of 0.03 M extractants were found to be 1.07-1.1gpl, corresponding to 95.2-97.9 % of their theoretical loading capacity, which indicates that the extractants are almost in pure form. The influence of NaCl, NaNO_3, NaSCN and NaSO_4 on the extraction of metal ion has been investigated. Synergistic extraction of cadmium has been observed with the binary mixtures of the three extractants. Based on the data synergistic coefficients were determined and best extractant mixture system was suggested. The extractants could be arranged in the order of increasing synergism as PC-88A >Cyanex-272 >TOPS-99.