Industrial & Engineering Chemistry Research, Vol.41, No.12, 2948-2952, 2002
Recovery of chromium and nickel from industrial waste
The paper embodies an analytical approach to the recovery of chromium and nickel from different kinds of industrial wastes, namely, a Cr(III)-Ni(II) plating sludge, a Ni(H) plating mug, and a tannery effluent. The proposed methods employ precipitation, solvent extraction, and electro-winning steps, A toluene solution of Cyanex 923 is used as an extractant for the separation of Cr(III) and Ni(II) from some commonly associated metal ions such as Al(III), Fe(III), Mn(II), Co(II), Cu(II), Zn(II), and Pb(II). The experiments conducted up to 10 cycles indicate a negligible loss in extraction efficiency. The electrodeposition of Cr(III) and Ni(II) offers average cathode efficiencies around 40 and 75%, respectively. The recovered metals are 99.9% pure. The proposed procedures will be helpful in saving the wastage of metals and protecting the environment from metal pollution.