Leaching of steel-making wastes in organic acids

Steelmaking dust and sludge are hazardous waste materials containing leachable compounds of zinc, lead, cadmium, and other environmentally harmful elements. In this study, acetic and butyric acid were used as leaching reagents to remove easily soluble zincite selectively. The effect of the acid concentration, liquid/solid ratio, temperature and time on the metal extraction and selectivity were studied. The results for the acetic and butyric are similar. Zincite can be selectively removed using diluted acids. Most of calcium was also leached. Zinc ferrite remained in the solid residuum. The selectivity decreases with the increasing time, temperature and acid concentration. The leach liquor can be used for the preparation of nanomaterials for photocatalysis. The solid residue will be studied using the electrochemical methods and thermal analysis with the view of finding some application.