A chemical composition analysis of the leachate in the process of producing alumina from fly ash using the acid method was conducted.Aluminum and iron were found to be the main elements in the leachate,with an aluminum concentration of 263.5 g/L (calculated as aluminum chloride) and a total iron concentration of 4.4 g/L (calculated as FeO),where the Fe2＋ concentration was 2.17 g/L (calculated as FeO).A kinetic study on the oxidation of ferrous ions by air,oxygen-enriched gas,and ozone was carried out.Kinetic equations for the oxidation of ferrous ions by these 3 gaseous oxidants were obtained,and the oxidation rates were compared.The oxidation rate by ozone was found to be 1.7 times that of oxygen-enriched gas and 1.9 times that of air.