Bioleaching of İskenderun Iron-Stell Plant waste sludges

In this study, bioleaching and chemical leaching methods were used for Iskenderun Iron-Stell Plant waste sludge. The bacteria, A. Ferrooxidans, used in bioleaching, obtained from DSMZ. The effects of solids rate, bacterium density and particle size were investigated on the bioleaching process. For each parameter applied, pH, mV, temperature, bacteria quantity, Fe and Zn content were measured. Using ANOVA-Yates test technique, the effects of solids rate, temperature, particle size and acid rate were investigated on the chemical leaching process. Solids rate increased with decreasing dissolution rates of Fe and Zn, increase of bacteria quantity and decrease of particle size resulted in increasing dissolution rates of Fe and Zn on the bioleaching process. Acid rate and temperature were affecting parameters on the chemical leaching. The removal/recovery of metals was determined as: 37% Fe and 35% Zn for bioleaching; 51% Fe and 85% Zn for chemical leaching. Values of k were determined as 0.0009 and 0.0007 day-1 for Zn and Fe on the bioleaching process, respectively. Key Words: Bioleaching, Chemical leaching, A. ferrooxidans, Waste sludge