Microwave assisted leaching of copper anode slime based on Taguchi methods

An optimization method of microwave assisted leaching of copper anode slime was proposed based on Taguchi method for signal noise ratio (SNR) and variance analysis of the copper, tellurium and selenium leaching rates. The results shows that the solid-liquid ratio is the most important factor affecting SNR of the copper, tellurium and selenium leaching rates, and its contributions to the copper, tellurium and selenium leaching rates reach 60.83%, 54.76% and 62.05%, respectively. Solid-liquid ratio is a significant factor of the microwave leaching process of copper. Reaction time is a less significant factor of the leaching process of copper and tellurium and concentration of sulphuric acid is a less significant factor of the leaching process of selenium, while microwave power is an non-significant factor, its contributions to the copper, tellurium and selenium leaching efficiency reach 4.23%, 12.37% and 10.32%, respectively. The optimized parameters of the microwave assisted leaching of copper are as follows: microwave power 450 W, reaction period 5min, solid-liquid ratio 0.10 g/mL and concentration of sulphuric acid 1.0 mol/L. The optimized parameters of the microwave assisted leaching of tellurium and selenium are as follows: microwave power 700 W, reaction period 9min, solid-liquid ratio 0.10 g/mL and concentration of sulphuric acid 1.0 mol/L. The validation experiments under the optimized conditions was carried out, the leaching rates of copper, tellurium and selenium reach above 99.88%, 95.70% and 38.22%, respectively. ©, 2014, Science Press. All right reserved.