Optimization of the treatment process of zinc leaching residue by using the response surface method

Abstract

Abstract The decrease in the zinc volatilization rate is usually due to the liquid phase, which is typically generated in the rotary kiln. The response surface model was built to analyze and explore the effects of carbon content, basicity, and holding time on the zinc volatilization rate and residue state. Moreover, the model was used to optimize the experimental conditions. The results showed that the effect of basicity on zinc volatilization rate was statistically significant, whereas the effects of carbon content and holding time were relatively small. The optimized process conditions were as follows: carbon content of 32%, basicity of 3, and holding time of 30 min. Under this condition, the zinc volatilization rate was 99.65%, and the furnace residue was sintered, which proved to be beneficial to the subsequent step of iron extraction.