Local-specific optimal selection and interprovincial embodied benefits of secondary aluminum dross reutilization in China

The importance of secondary aluminum dross (SAD) recovery to ease the bauxite shortage has been widely recognized. However, previous studies overlooked regional differences at provincial levels may result in misunderstandings about actual environmental impacts and best technologies. This study investigated the local-specific optimal selection and interprovincial embodied benefits of SAD reutilization with an integrated multi-regional input-output-based hybrid life cycle assessment and scenario analysis. Regarding CO2 emissions, energy use, and economic benefits of SAD reutilization, SAD-to-calcium aluminate is the best option in Jiangsu and Chongqing provinces. In contrast, Shandong, Henan, Guangdong, and Qinghai provinces prefer SAD-to-aluminum oxide. Meanwhile, SAD-to-concrete brick and SAD-to-calcium aluminate are less favorable choices. Furthermore, the scenario with optimal SAD reutilization pathway in the above six provinces would significantly reduce national bauxite consumption by 7.14 million tons. This study provides a reference for technology comparison and emerging industry layout in countries with inter-regional economic and industrial structure imbalances.