Efficient trivalent bath for the recovery of chromium

An electroplating bath for the deposition of chromium from its trivalent so lution in dilute sulfuric acid is proposed. A simple two-compartment cell w ith a cylindrical silver anode and a rotating copper disc cathode has been employed. The effect of factors such as concentration of cr(III) and H+ ion s, role of additive and current density on the deposition rate has been stu died. At an average current density of 125 A/dm(2), a cathode efficiency of around 45 percent is achieved from a bath containing 7 g/L cr(III) and 1 g /L Na2SO4 maintained at a pH of 1.4. The deposits are in semibright nodular form. The practical utility of the proposed bath has been demonstrated by recovering pure chromium from chromium-laden effluent from a tannery.