The aluminum production chain from bauxite to primary aluminum includes refining using the Bayer process, and smelting through electrolysis. This production chain produces two main solid residues, red mud at the refinery and spent pot lining at the smelter. The use of these residues as raw material for other industrial processes can save large amounts of energy, reduce the overall environmental impact, and even improve the emissions of other processes. This paper shows the results of ten years of co-processing of spent pot lining in the cement industry in Brazil and the efforts to develop technologies to reduce the reactivity and use the red mud as raw material for several different processes. This approach, although engineering intensive, can reduce CO_2 emissions and save huge amounts of wasted energy in transport and processing when compared with dedicated recycling or neutralizing processes.
展开▼