Research On Alumina Leaching Through Different Processes From Fly Ash

Fly ash was roasted with Na2CO3 to strengthen aluminum leaching. Different successive processes such as acid leaching and microwave acid leaching were investigated comparatively. The results showed that the highest leaching rates of aluminum with acid leaching and microwave acid leaching were 42.38% and 59.17%, respectively. It could be deduced from the XRD, SEM and EDS characterization results of roasted fly ash that roasting fly ash with Na2CO3 destroyed SiO2-Al2O3 bond of mullite and generated such high active material as NaAlSiO4. In addition, microwave heating raised the internal energy of reactant elements and decreased activation energy of reaction, which shortened the reaction time and increased leaching rate of aluminum from fly ash.