Response Surface Methodology for Optimization of the Chloridizing Roasting Process for a High Copper Pyrite Cinder

This study aimed to obtain volatile copper from a high-copper pyrite cinder by optimizing the chloridizing roasting process using response surface methodology (RSM). The effect of key parameters, i.e., dosage of CaCl2 addition, roasting time and roasting temperature, on the copper volatile ratio was investigated and a quadratic model was suggested by the methodology to correlate the variables to this volatile ratio. The results indicated that the model was in good agreement with the experimental data at a correlation coefficient (R-2) of 0.9782, and the most influential parameter on efficiency was identified as the dosage of CaCl2 addition. The optimum conditions for chloridizing roasting from the high copper pyrite cinder were identified as a dosage of CaCl2 addition of 4.8 wt%, a roasting time of 19.28 mm and a roasting temperature of 1151.51 degrees C; under such conditions, a copper volatile ratio of 97.82% was achieved. The pellets obtained by this process are characterized by a high content of hematite, and the main impurity element contents are consistent with the requirements for iron concentrate, which is suitable for use in ironmaking.