SOLVENT-EXTRACTION OF TUNGSTEN BY ALKYLAMINES HYDROCHLORIC-ACID AND ALKYLAMINES SULFURIC-ACID SYSTEMS

The extraction of W(VI) from 0.01 M aqueous solutions in hydrochloric and sulphuric media with various concentrations of Cl- (1 and 5 M), SO4(2-) (1.36 M) and CO3(2-) (0.05, 0.1, 1, 5 and 25% (w/v)) ions by chloride and sulphate salts of primary (Primene JM-T), secondary (Amberlite LA2) and tertiary (Alamine 336) amines and a quaternary ammonium salt (Aliquat 336), was studied at three pH values (2, 7 and 12), using a 9:1 mixture of kerosene and isodecanol as solvent. The tungsten stripping from the resultant pregnant organic solutions at pH 2 was carried out using: NH4Cl, NaCl, NaOH, Na2CO3, (NH4)2CO3, equimolar NaOH + NaCl and NH4Cl + NH4OH solutions with variable concentrations. The relative efficiency of the different extractants and stripping agents was compared.