Recovery of gibbsite from secondary aluminum production dust by caustic leaching

The disposal of aluminum bearing dust can cause heat and gases, as well as the potential generation of leachate from landfills. In this research, we suggested a two-step process - leaching and precipitation - for recovering gibbsite from secondary aluminum production dust. First, a sodium eliminate solution, containing about 20 g/L of aluminum, was prepared using 1 M of sodium hydroxide leaching. Precipitation of the gibbsite was then conducted for 30 min after a pH adjustment. As the results indicate, the overall aluminum recovery rate was about 87% by weight after leaching and precipitation, and the major component of the precipitate was Al(OH)(3) based on an X-ray diffraction(XRD) analysis.