Life cycle environmental and economic assessment of alumina recovery from secondary aluminum dross in China

Secondary aluminum dross is regarded as a hazardous solid waste in many countries. A coupled life cycle assessment and life cycle costing method was used to evaluate the environmental impact and economic cost of two processes for producing alumina from bauxite and secondary aluminum dross. The results showed that the total normalized midpoint value of the dross process is 32.16% lower than that of the bauxite process. The cost of producing 1 t alumina by dross process is 130.01 $, accounting for only 49.54% of that of bauxite process. Ammonium sulfate as a by-product also brought in a profit of 22.18 $. These findings could be attributed to the decrease in energy and raw material consumption (i.e., steam, sodium hydroxide, electricity) and the relatively low cost of secondary aluminum dross. Adjusting raw materials for steam production and optimizing electricity structure could reduce the overall environmental impact of secondary aluminum dross recovery. Based on the forecast of environmental impact and policy adjustment in the future, inter-provincial dross transportation and southwest aluminum industry migration in China could be feasible solutions. (C) 2020 Elsevier Ltd. All rights reserved.