Study on the Extraction of Valuable Components from Aluminum Electrolysis Spent Carbon Anode by Mechanical Activation Assisted Flotation

Spent carbon anodes (SCAs) possess significant environmental risks and secondary resource properties. The current flotation method for recovering valuable components exhibits suboptimal purity and efficiency. This paper focuses on the extraction of valuable components from SCAs via mechanical activation-assisted flotation. Flotation parameters were optimized under mechanical activation intensification. Subsequently, the effects of flotation parameters on the flotation rate were explored. The enhancement mechanism of flotation via mechanical activation was quantified and proposed from a kinetic perspective. Results demonstrated that the activated SCA exhibited higher carbon content and flotation rate constant compared with the unactivated samples under identical flotation parameters. The selection and sweeping processes of SCA flotation were further determined, and a complete closed-circuit flotation process was established. Results demonstrated that the carbon content and recovery rate of the extracted carbon concentrate achieved 90.58% and 77.87% by mechanical activation-assisted flotation, respectively. Finally, numerous characterization techniques were used to characterize the recovered carbon concentrate. Recovered carbon is suitable for resource utilization as a fuel and carbon enhancer because of its high carbon content and low sulfur content. The proposed method of mechanical activation-assisted flotation is anticipated to serve as the primary approach for extracting valuable components from SCAs.