Separation of copper from chalcopyrite leach liquor containing copper, iron, zinc and magnesium by supported liquid membrane

Abstract

A low-grade chalcopyrite ore was leached with H2O2/H2SO4 solution and the leach liquor contained 50.83 copper, 15.59 zinc, 30.43 iron and 3.20 mol/m(3) magnesium. From the leach liquor, separation of copper was carried out with the supported liquid membrane (SLM) using LIX84I as the mobile carrier, and distilled kerosene as the diluent. Celgard 2400, a microporous polypropylene film was used as the solid support for the liquid membrane. The effect of various parameters such as flow rate, pH of feed solution, extractant concentration in the membrane phase and acid concentration in the strip solution was investigated to obtain the optimum conditions for separation. It was observed that the flux of copper increased from 1.79 to 4.72 x 10(-5) mol/m(2) s with increase in flow rate from 20 to 120 mL/min after which the flux was decreased. Further, the flux of copper increased from 0.782 to 2.939 x 10(-5) mol/m(2) s and from 1.751 to 4.727 x 10(-5) mol/m(2) s with increase in pH from 1.5 to 2.5 and LIX84I concentration from 10 to 40%, respectively, but with further increase in pH and extractant concentration the flux of copper was decreased. The co-permeation of Zn, Fe and Mg with Cu was within 0.12-0.15, 0.089-0.10 and 0.82-1.03 mol/m(3), respectively. The experimental data were explained by mathematical equations describing the rate of transport. The forward reaction rate constant k(1), the diffusivity of the complex through the membrane (D) over bar, and the aqueous film diffusion constant k(w), were calculated to be 1.34 x 10(-8)/1.82 x 10(-8) m/s, 4.94 x 10(-10) m/s and 1 x 10(-6) m/s, respectively. (C) 2008 Elsevier B.V. All rights reserved.