Effect of fractional precipitation on quality of nanostructured alumina produced from aluminium metal wastes

Abstract

Black aluminium dross produced from a local aluminium smelting plant was used in this study. Solvothermal method was used to produce nanostructured alumina from this waste. Initial product obtained is of low quality with 86.9% Al2O3 content and mixed crystalline phases of 71% -alumina and 29% calcium dodeca aluminate (CaO(Al2O3)6). The introduction of the fractional precipitation stage into the process helps in improving the purity of the alumina product to 96.5% and also produces 100% -alumina crystalline phase. The study also shows that the crystallite size of the -alumina products produced from this process is less than 100nm.