Characteristic Analysis of Hazardous Waste from Aluminum Reduction Industry

The carbon dust, aluminum dross and spent potlining from aluminum reduction cells are considered to be hazardous materials because they contain a large amount of soluble fluoride salts and trace amounts of toxic cyanides. Piling them outside or in landfill sites create environmental pollution and ecological problems. In this paper, the hazardous wastes were comprehensively investigated with scanning electron microscopy (SEM) and X-ray diffraction (XRD). It is found that the chemical compositions of these wastes are very complicated. A variety of fluoride salts and aluminum metal were embedded in pores and openings of lining materials such as carbon, silicon carbide and refractories. As a result, a variety of compounds have been formed. The disposal of hazardous waste is hampered by these complex components. This work provides some insight into dealing with such hazardous waste.