Determination of the Optimum Conditions for Leaching of Malachite Ore in H2SO4 Solutions

Abstract

The Taguchi method has been used to determine the optimum conditions for the dissolution of malachite ore in H2SO4 solutions. The chosen experimental parameters and their range were (i) reaction temperature: 15 to 45 °C, (ii) solid-to-liquid ratio: 1/10 to 1/3 g cm–3, (iii) acid concentration (in weight): 2 % to 10 %, (iv) particle size: –40 to –3.5 mesh, (v) stirring speed: 240 to 720 rpm, and (vi) reaction time: 5 to 45 minutes. The optimum conditions were found to be reaction temperature: 40 °C, solid-to-liquid ratio: 1/3 g cm–3, acid concentration (in weight): 10 %, particle size: –30 mesh, stirring speed: 480 rpm, and reaction time: 45 minutes. Under these optimum working conditions, the dissolution of copper and iron in malachite ore was 100 % and 58 %, respectively. Besides, alternative working conditions reducing the total cost and dissolution of iron were found.