Preparation of Alumina from Fly Ash by Sulfuric Acid

Abstract

Extraction metallurgy level alumina from fly ash through high-pressure leaching, removing iron, crystallizing and roasting processes were considered. The optimum conditions of high-pressure leaching, removing iron and roasting processes were obtained by experiments. The leaching rate of Al2O3can reach 93.1% and the purity of Al2O3product can reach above 98% under these conditions. The iron content in Al2(SO4)3solution can decrease from 1.21% to 0.10% when fly ash as alkaline agents.