Abstract:
Pyrite cinder is one of the important secondary resources; however, the arsenic typically contained in pyrite cinder is harmful to metallurgical process. The removal of arsenic can improve the value of pyrite cinders. Thus, a pretreatment method for removal of arsenic from pyrite cinders using a Na
2S-NaOH solution was investigated in this paper. A single factor experiment was conducted to determine the appropriate concentration ranges of NaOH and Na
2S, and then the response surface methodology (RSM) was used to optimize the leaching parameters. The results indicate that the optimized RSM model is reliable. The temperature, NaOH concentration, and Na
2S concentration have significant effects on the arsenic removal. The higher temperature is found to be favorable to the leaching of arsenic, and a significant interaction is found between the concentrations of NaOH and Na
2S. The content of arsenic in the leaching slag can be reduced to 0.08% at 80℃ when the concentration of NaOH and Na
2S is 0.34 and 0.12 mol·L
-1, respectively.