Comprehensive benefit evaluation and optimization of associated metal element management in copper smelting process

With the depletion of high-grade copper ores and growing global copper demand, the smelting industry is forced to use low-grade ores and copper-containing solid wastes, leading to higher impurities and challenges to production and environmental safety. Future copper smelting management requires integrated and refined approaches. Comprehensive management grounded in primary and associated metal distribution can enhance both environmental and economic performance. This study established a five-dimensional evaluation index system for associated metal distribution issues. Single-objective benefits were evaluated under different scenarios (ore grade limits, energy restrictions). Data Envelopment Analysis (DEA) was used to assess comprehensive benefits and identify refinement opportunities. Dominant optimization factors and adjustment directions were analyzed to propose a refined operational strategy based on industrial production conditions. Results showed that low-grade ores enhanced economic benefits by 14.8%, while high-grade ores reduced heavy metal toxicity and improved resource recovery. Primary energy restrictions improved production efficiency by 9.9%, whereas secondary energy restrictions reduced carbon emissions by 5.9%. Using baseline scenario averages as typical conditions, multiple adjustment schemes were generated by sampling key variables within technical limits. Under the optimized scheme, the heavy metal toxicity, carbon emissions, production efficiency, resource reuse, and economic benefits were improved by 12.7%, 26.0%, 22.6%, 15.7%, and 11.1%, respectively. Local Interpretable Model-Agnostic Explanations identified key variables contributing to single-objective improvements. This study offers methodological guidance for refined hazardous metal management and benefit optimization in copper smelting.