A Novel Approach for Comprehensive Utilization by Leaching Pyrite Cinder with Titanium Dioxide Waste Acid by Response Surface Methodology

Comprehensive utilization of two industrial wastes by leaching pyrite cinder with titanium dioxide waste acid was proposed by using response surface methodology of the Box-Behnken design method. The effects of leaching conditions such as leaching temperature, leaching time, and waste acid/pyrite cinder ratio on the leaching yield were examined. The prediction model including the leaching variables with a good fitting result was established to predict the leaching yield or optimize the leaching variable values. The regression equation model was significant and reliable with an actual correlation coefficient R² of 0.9856. The leaching conditions greatly affected the leaching rate, reaction equilibrium, solubility of the acid decomposed substances, and the common ion effects, influenced the leaching process, and finally improved the leaching yield. The variables such as leaching temperature and waste acid/pyrite cinder ratio had the greatest collaborative interactions, and the effects of the waste acid/pyrite cinder ratio were larger than the other two. The verification experiments confirmed that the leaching yield values could be achieved at 82.68 % under the optimal conditions.