A. Sandhibigraha et al., SOLVENT-EXTRACTION OF IRON(III) FROM AQUEOUS HYDROCHLORIC-ACID SOLUTIONS USING D2EHPA, PC-88A, CYANEX-272 AND THEIR MIXTURES, Scandinavian journal of metallurgy, 25(3), 1996, pp. 135-140
Background/purpose. D2EHPA, PC-88A and cyanex-272, the phosphoric acid
based solvents are widely used in the solvent extraction of non-ferro
us, nuclear and other metals. However, information on their use, espec
ially the latter two, for iron extraction is limited. As many hydromet
allurgical leaching techniques used for recovering non-ferrous metals
result in solutions containing the desired metals as well as iron and
as solvent extraction is one of the commonly used technique for metal
recovery/separation, detailed information on the extraction behaviour
of iron with these solvents is very much essential. Methods. Extractio
n studies were carried out on laboratory scale using separatory funnel
s. The acid concentration was adjusted to the desired value before equ
ilibration. The extractants were diluted with kerosene. After phase se
paration, iron analysis was carried out by atomic absorption spectroph
otometry/titration method. Results and conclusions. Iron extraction wa
s found to vary with HCl concentration. The loading capacity of 0.1 M
D2EHPA, PC-88A and cyanex-272 was found to be 1.7, 1.3 and 1.8 kg/m(3)
respectively. Sodium sulphate and sodium chloride lowered iron extrac
tion efficiency, while sodium nitrate enhanced the extraction efficien
cy. Synergism was observed with binary mixtures of the extractants.