Harmless recovery and utilization of electrolytic aluminum spent cathode carbon block: A comprehensive review

Spent cathode carbon block (SCCB) is one of the hazardous solid wastes generated in the electrolytic aluminum. Traditional landfills contaminate the environment, and waste resources. Therefore, the harmless treatment and the effective recovery of SCCB will be an urgent challenge. First, the complex physicochemical properties of SCCB, and the hazards caused to the environment are introduced. Recovery strategies and methods for the safe disposal and resource utilization are then described in detail. Flotation recovery in physical methods is proven to be economically and efficiently superior and has been industrialized. Hydrometallurgy describes various methods and techniques for selective recovery of valuable elements from leachate and preparation of products. Pyrometallurgy presents processes for the incineration, molten salt roasting, collaborative disposal, and material preparation. Finally, the remaining challenges and prospects of SCCB reuse should be in the direction of non-pollution, low cost, low energy and high value are emphasized. This study provides guidance for the subsequent green resource-based recycling of SCCB and alleviates various scientific and technological challenges of hazardous waste recycling in a circular economy.