Investigating the Effect of Thermal Pretreatment on Chalcopyrite Grinding for Comminution Energy Reduction

This study investigates the effect of thermal pretreatment on the grindability and energy efficiency of chalcopyrite ore using a ball mill, employing Box–Behnken design and statistical analysis to optimize key grinding parameters. The research utilized scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) to assess the structural changes in the ore after pretreatment at 300 °C and 600 °C. These analyses revealed significant modifications in the chalcopyrite structure, including reduced crystallinity, formation of new phases (such as oxides), and the development of microcracks, which contributed to improved grinding performance. Statistical analysis of the results showed that thermal pretreatment reduced specific energy consumption by approximately 10% and enhanced the particle size reduction (P80). The Box–Behnken design was used to optimize the mill speed and ball filling ratio, further improving energy efficiency. Results showed that reducing the mill speed decreased energy consumption while maintaining an optimal P80, whereas increasing the ball filling ratio reduced energy usage but resulted in a coarser product. Overall, this study demonstrated that thermal pretreatment, combined with optimized milling parameters through statistical design, can significantly enhance energy efficiency and grinding performance in chalcopyrite ore processing, offering practical solutions for industrial mineral processing.