Life cycle assessment of valuable metal extraction from copper pyrometallurgical solid waste

China generates about 20 million tons of solid waste for copper production each year, most of which comes from pyrometallurgy, leading to substantial environmental problems. Extracting valuable metal is a common way of recycling copper pyrometallurgical solid waste (CPSW). However, its environmental effects are still unclear. This paper adopts a cradle-to-gate life cycle assessment to assess the impacts of recycling three main types of CPSW (smelting slag, copper ash, and anode slime). Results show that the prominent contributor to the environmental impacts is electricity consumption. The sensitivity analysis demonstrates that reducing electricity consumption and optimizing the electricity grid mix can reduce the environmental impact. The comparative analysis was conducted to investigate the environmental advantages between CPSW recycling and primary metal production. The results indicate that the impacts of CPSW recycling are 86%, 52%, and 79% lower than that of copper concentrate production, primary copper hydrometallurgy, and primary gold production.