Kinetics of aluminum extraction from roasting activated fly ash by sulfuric acid leaching

The process of extracting aluminum with sulfuric acid from high-alumina fly ash activated by roasting with Na 2 CO 3 and NaOH as raw materials ware studied. The results revealed that the aluminum in fly ash activated by sodium carbonate reached 93.2% under the optimum conditions (30% H 2 SO 4 , 90°C, 120 min, and liquid-to-solid ratio was 5:1). Simultaneously, the leaching rate of aluminum in fly ash activated by sodium hydroxide reached 92%. The study of kinetics suggested that the leaching process with sulfuric acid was controlled through chemical reactions; it conformed to the kinetic equation: 1 − (1 − X ) 1/3 = 22.924 exp[− 25174/( RT )] t . Graphical abstract Extracting aluminum with sulfuric acid from high-alumina fly ash activated by roasting with Na 2 CO 3 and NaOH as raw materials.