SYNERGISTIC EXTRACTION OF VANADIUM BY DI-2-ETHYL HEXYL PHOSPHORIC ACID AND TRIBUTYL PHOSPHATE FROM BLACK SHALE SEDIMENTS, QUSEIR, RED SEA, EGYPT

Extraction of vanadium from the sulphate leach liquor of the black shale from Nakheil mine NW Quseir,
red sea, Egypt was studied by using a synergistic mixture of di-(2-ethylhexyl) phosphoric acid (DEHPA)
and tributyl phosphate (TBP) in kerosene. A technological sample of this ore material assaying about 2400
μg/ml V, 2300 μg/ml Zn, 570 μg/ml Mo, 1.6 % Fe and 272 μg/mL Ni was collected for the present work.
Metallic iron powder was found greatly an advantage to minimize the iron co-extraction, while adjusting
the pH of aqueous solution to 0.8 minimized the co-extraction of Zn and Ni. The relevant extraction
factors affecting maximum recovery of vanadium have been studied; namely solvent ratio (DEHPA/TBP),
concentration of solvent, O/A phase ratio, contact time, settling time, temperature, the amount of reducing
agent and the time of reduction. Selective stripping of vanadium has been performed using 100g/L Na2CO3
while Mo was left in the organic phase. The relevant stripping factors affecting maximum stripping of
vanadium have been studied namely; O/A phase ratio, contact time, settling time, and the temperature.