Response Surface Methodology-Based Evaluation of Chemical and Biological Leaching Performance of a Complex Sphalerite Ore

In this study, the chemical leaching and bioleaching behaviors of a complex carbonate-rich sphalerite ore were statistically evaluated using Response Surface Methodology (RSM) based on Central Composite Design (CCD) and the effects of process parameters on Zn and Fe recovery were assessed. The maximum Zn recovery obtained in the chemical leaching process was 59.16%, while the maximum Zn recovery in the biological leaching process was determined to be 37.26%. Statistical analyses showed that the solid-to-liquid ratio and leaching time had a significant effect on chemical leaching performance, while the effect of Fe(II) concentration on biological leaching performance was limited. During biological leaching, pH increases occurred due to the ore’s carbonate-rich structure, and periodic sulfuric acid adjustments were made to maintain suitable biological leaching conditions. The findings indicate that carbonate-rich mineral structures significantly influence both chemical and biological leaching behavior, and that this effect must be taken into account in the processing of complex sphalerite ores.