Recovery of metal oxides from Afşin-Elbistan power plant fly ashes leaching method

In this study; mineralogical, physical and chemical properties of Afşin-Elbistan fly ash with recovery of metal oxides such as Al, Fe and Ti by leach methods were investigated. The representative sample of fly ash consists of mainly CaO and SİO2 along with 7.54 % AI203, 4.02 % Fe203 and 1.02 % Ti02. Mineralogical analyses indicated that quartz, lime, anhydrite, brown millerit and anhydrite+melilit were evident in the fly ash. Direct acid leaching experiments were carried out for recovery of Al, Fe, and Ti from fly ash. The best results are acid concentration of 300 g/lt, temperature of 90 C°, mixing rate of 1500 rpm, solid/liquid rate of 5% solids at the extraction time of 6 hours for Al and Ti, 8 hours for Fe. Using this conditions 97% Al, 95% Fe and 98% Ti extraction recoveries were obtained.