Researches and applications of pollution prevention and control technologies for carbon dross from electrolytic aluminium production: a review

Abstract

This review focuses on the long-overlooked carbon dross from aluminum electrolysis, a hazardous waste enriched in carbon and high-fluoride salts, despite its relatively low generation volume. With the continuous expansion of global aluminum production, the output of carbon dross has increased accordingly, yet its environmental risks and resource potential have not received sufficient attention. For the first time, this article provides an examination of carbon dross following a “generation-hazards–prevention-control” framework. It elucidates the formation mechanism via corrosion, spalling, and entrainment of carbon anodes in electrolytic cells, and analyzes the release behavior and ecotoxicological effects of its toxic components. The limitations of existing end-of-pipe treatment technologies are critically assessed. Furthermore, based on the 3C (clean-cycle-control) green development strategy, a management framework is proposed: clean first, through the adoption of inert anodes, energy-efficient electrolysis processes, and intelligent optimization to minimize dross generation at the source; for unavoidable dross, the cycle is employed to achieve high-value recovery of aluminum fluoride and functional carbon materials; finally, by integrating cross-scale environmental risk assessment and policy instruments, a science-technology-management integrated control decision-making system is established, offering a paradigm for low-carbon, high-value, and safe management of carbon dross.