SOLVENT EXTRACTION OF MOLYBDENUM(VI) FROM ACIDIC SOLUTIONS WITH HEXAN-1-OL AND 4-METHYL-2-PENTANONE (METHYL ISOBUTYL KETONE).

Abstract

The solvent extraction of molybdenum(VI) from hydrochloric acid solutions has been studied in the presence of KCl as a salting-out agent with hexan-1-ol and 4-methyl-2-pentanone (methyl isobutyl ketone or MIBK) as extractants when equilibration was maintained for 5 min for the batch extraction process. The stripping of molybdenum(VI) was performed by using 96 %v/v NH3 solution. The effect of various parameters such as metal ion and hydrochloric acid concentrations, temperature, number of extraction cycles, recycling and mixing of extractants, and foreign ions on Mo(VI) extraction were investigated. From the equilibrium studies, the recovery of Mo(VI) with hexanol was quantitative with percentage extraction (%E) reaching a peak of 70.8 % at 2 M HCl varies from 41.3-70.8 %), while with MIBK, it was lower, with extraction of 57.8 % as highest. The optimum extraction temperatures were 28 °C and 38 °C for hexanol and MIBK respectively. On recycling, the percentage extraction of Mo (VI) was at the peak at first stage with both extractants. All the added extractants (octanol, decanol, TBP, MIBK and D2EHPA) to 50 % (v/v) Hexanol all inhibited Mo(VI) extraction with octanol having the greatest effect. The addition of vanadium (0.001M NH4VO3) as a foreign ion inhibited the extraction of Mo(VI) for both extractants. Electronic and infrared spectra data have also been used to clarify the nature of the organic phase extracts.