Copper Flash Smelting Flue Dust as a Source of Germanium

Economic and environmental benefits may be obtained by extracting certain resources from industrial waste instead of natural sources. Flue dust from Cu smelting is a potential source of Ge, since relatively high contents of this element may be present in Cu-sulphide ores. This study focuses on evaluating Cu smelting flue dust as a potential source of valuable elements. Chemical and mineralogical characterisation of Chilean Cu flue dust and the leaching potential of Ge (and other elements) were performed with different chemical leaching agents. Cu smelting flue dust presents fine particle size with high enrichment of small crystals, mainly composed of As, S, Pb, Zn and Cu minerals (sulphides and sulphates). Extraction with water revealed Li, Rb and Ge yields between 97.2 and 100 %, suggesting their occurrence as soluble species. In view of the high leaching yield achieved, Cu smelting flue dust may be considered a promising material for the extraction and recovery of Ge