Effects of Additive and Roasting Processes on Nitrogen Removal from Aluminum Dross

Abstract

Taking high nitrogen aluminum dross as the research object, the effects of the additives sodium carbonate and cryolite and the roasting process on the denitrification effect of aluminum dross were studied. The principle of additive denitrification was studied by XRD, SEM and TG-DSC. The experimental results show that sodium carbonate and cryolite can quickly reduce the content of aluminum nitride in aluminum dross. The optimum denitrification process parameters were also obtained simultaneously. When the mass ratio of cryolite to aluminum dross was 0.4, the roasting temperature was 900 °C, and the roasting time was 3 h, the denitrification degree could reach 96.19%. When the mass ratio of sodium carbonate to aluminum dross was 0.8, the roasting temperature was 1000 °C, and the roasting time was 4 h, the denitrification degree could reach 91.32%. This study provides a reference for the non-harmful treatment of high nitrogen aluminum dross.

A New Strategy on Designing Fluxes for Aluminum Alloy Melt Refinement

“…Finally, the bubbles float up to the surface of the aluminum melt and burst. According to the studies of Utigard et al [ 19 ], Na 2 CO 3 in the flux will form bubbles within the aluminum melt by the following reaction, and remove the hydrogen that is dissolved in the aluminum melt [ 57 ]: …”

Optimizing Wet Hydrolysis for Nitrogen Removal and Alumina Recovery from Secondary Aluminium Dross (SAD)

“…Therefore, the first priority in the treatment of SAD should be harmlessness, with denitrification as a potential option [9]. The denitrification of SAD can be achieved through dry roasting or wet hydrolysis [10][11][12][13]. However, dry roasting denitrification demands a high temperature and advanced equipment, whereas wet hydrolysis denitrification requires only low equipment investment and can be easily industrialized [14][15][16].…”