Bioleaching of Zinc from Blast Furnace Cast House Dust

Metallurgical dusts are by-products from steel manufacturing. The high iron content of cast house dust (~64%) makes this by-product an interesting feedstock alternative. Therefore, its return into the internal steelmaking circuit, specifically in sinter plant, is a common practice industry. However, fraction also contains heavy metals, as zinc. As result re-entry zinc process, concentration blast furnace flue gas increases. This prevents full recirculation process despite relatively (~35%), thus causing part to end landfill. goal study was investigate usage bacteria, such sulfur oxidizing Acidithiobacillus thiooxidans or and ferrooxidans, leach undesirable element while preventing leaching iron, by adjusting addition avoiding, at same time, accumulation solid fraction. Experiments proved that co-culture A. ferrooxidans can effectively metallurgical dusts, maintaining concentrations material. influence elemental on efficiencies reached shown, since higher removal were achieved with increasing concentrations. Maximum ~63% (w/w) enrichment ~7% remaining residue 15 g/L for 125 g/L.