CANADIAN METALLURGICAL QUARTERLY, cilt.46, sa.2, ss.107-114, 2007 (SCI-Expanded)
In this study, selective leaching of copper with NH3(aq) from ore containing malachite, SiO2, Al2O3 and Fe2O3 was optimized by using the Taguchi method. After determining the parameters and their levels affecting the leaching efficiency, the experiments were planned using an orthogonal array technique in an L-25 array with six parameters. It was determined that aqueous ammonia is unsuitable for leaching ore containing malachite. The effect of CO2, (NH4)(2)CO3, (NH4)(2)SO4 and NH4Cl on leaching malachite with NH3 (aq) was investigated. It was determined that NH3 (aq) + CO2 (9) is suitable for leaching malachite. The second experimental design using NH3 (aq) + CO2 as a leaching reagent was planned by means of orthogonal array technique in an L-18 array with seven parameters. Optimum leaching conditions for the second step were obtained as follows: temperature 42 degrees C, solid to liquid ratio 0.1 g.mL(-1), concentration of NH3 2.5 M, mean particle size 0.3375 turn, stirring speed 600 rpm, flow rate Of CO2 gas 61.64 mL.s(-1) and a reaction time of 50 minutes. For these conditions, 97.3% of the leaching efficiency was obtained.