Separation of molybdenum and vanadium from oxalate leached solution of spent residue hydrodesulfurization (RHDS) catalyst by liquid–liquid extraction using amine extractant

Abstract Alamine-336, diluted with kerosene and iso-decanol, was used for separation of vanadium (IV) and molybdenum (VI) from leached solution generated by oxalic acid washing of spent residue hydrodesulfurization (RHDS) catalyst. The variation of aqueous pH represented that there was complete extraction of both vanadium (IV) and molybdenum (VI) at equilibrium pH 3.8. Both metals were extracted by two stages counter current process using 10% Alamine-336 along with 5% iso-decanol at organic to aqueous phase ratio 1:2. The metal loaded organic was then used for selective stripping of each metal. About 99% of vanadium (IV) and molybdenum (VI) was selectively stripped with 1.5 M sulfuric acid and 2 M ammonia solution, respectively. Both stripped solutions can be further processed for the preparation of respective oxide components of vanadium and molybdenum.