Extraction of Valuable Metals from Trepca Landfilled Lead Smelting Slags with WELC Process

The landfilled slags obtained over the years from reduction smelting of lead agglomerates at the Trepca lead smelter contain numerous components as metal oxides and sulphides as well as metals in elementary state. Among others they contain various forms of Pb, Zn, Cu, Ag, Ge, Tl, In, As, Bi, Sb. These are valuable elements that may turn these slags to a new important “raw material” for their extraction. Based on the chemical composition results of 354 samples and mineralogical analysis then the quantity of these landfilled slag, which is estimated to be about 3 million tons it was concluded that these slags constitute a feasible waste for extraction of valuable metals. In order to select the optimal process for the separation/extraction of these metals some existing extraction processes were studied based on fuming, electro thermic separation etc. Waelz process was also analysed since it enables the processing of solid slag whose components have different vapour pressures, assures low rate of metal loss during processing and achieves generally good results in terms of economic feasibility