Underestimated environmental benefits of tailings resource utilization: Evidence from a life cycle perspective

Mineral resources are an essential foundation for economic and social development. However, many tailings generated and stockpiled during the mining process have become an obstacle to developing a low-carbon and green economy. In this paper, we selected copper tailings as a representative case study. First, we used material flow analysis for copper tailings in Tongling City and then constructed a life cycle assessment model. Finally, we set up a detailed scenario analysis of the carbon reduction benefits of copper tailings resource utilization. The results show that (1) the current comprehensive utilization of tailings is relatively single, with low added value, a common problem in the tailings resource utilization industry. (2) The resource utilization of tailings has positive environmental benefits. The global warming potential (GWP) is more prominent (e.g., preparation of cement and autoclaved blocks can achieve carbon emission reduction benefits of about 200 kgCO2/t tailings). (3) In a scenario in which the historically stockpiled tailings can be used rationally, the indirect carbon emission reduction is comparable to the carbon emission of power generation in Tongling City in one year. The resource utilization of tailings will relieve the pressure on resources and contribute to the realization of China's 'Carbon Peaking and Neutrality Goals,' with a significant benefit of emission reduction. At present, there are few such studies on bulk industrial solid waste. The research framework in this paper can provide reference for environmental impact assessment of other types of bulk industrial solid waste and provide policy guidance for industrial layout and development planning in similar resource-based and industrial cities and even at a larger scale.