Abstract
The extraction of chromium(VI) using TBP (Tri-n-butyl phosphate) and Cyanex 921(tri-n-octylphosphine oxide) in kerosene from hydrochloric acid and chloride media was studied. Different parameters affecting the extraction of the investigated metal ion such as hydrochloric acid, chloride ion, extractant and metal ion concentration were studied. The stoichiometry of the extracted metal species with Cyanex 921 was found to be (H(2)Cro(4 center dot)Cy921) over bar. In the case of TBP, the extracted species was found to be (H2CrO4 center dot TBP) over bar and (H2CrO4.2TBP) over bar at low TBP concentration and at high TBP concentration, respectively. The stripping of the extracted metal species was found efficient with 0.5 M NaOH solution. Thereafter, the method developed was applied for the recovery of Cr(VI) from a synthetic solution of electroplating bath. The efficiency of recovery reached 96% using Cyanex921 in kerosene.