Mine wastes and tailings derived from historical processing may contain significant contents of valuable metals due to processing being less efficient in the past. The Plombières tailings pond in eastern Belgium was selected as a case study to determine mineralogical and geochemical characteristics of the different mine waste materials found at the site. Four types of material were classified: soil, metallurgical waste, brown tailings and yellow tailings. The distribution of the mine wastes was investigated with drill holes, pit-holes and geophysical methods. Samples of the materials were assessed with grain size analysis, and mineralogical and geochemical techniques. The mine wastes dominantly consist of SiO2, Al2O3 and Fe2O3. The cover material, comprising soil and metallurgical waste is highly heterogeneous in terms of mineralogy, geochemistry and grain size. The metallurgical waste has a high concentration of metals (Zn: 0.1 to 24 wt.% and Pb: 0.1 to 10.1 wt.%). In the tailings materials, Pb and Zn vary from 10 ppm to 8.5 wt.% and from 51 ppm to 4 wt.%, respectively. The mining wastes comprises mainly quartz, amorphous phases and phyllosilicates, with minor contents of Fe-oxide and Pb- and Zn-bearing minerals. Based on the mineralogical and geochemical properties, the different potential applications of the four waste material types were determined. Additionally, the theoretical economic potential of Pb and Zn in the mine wastes was estimated.

Extraction of copper, lead and zinc from photovoltaic panel residue by microwave-assisted chloride leaching, followed by recovery of extracted metals from the pregnant leaching solution by cementation, ion flotation and precipitation.

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An integrated mineralogical and chemical characterization approach was applied to different types of mine waste collected from the ancient Pb-Zn mining area of Plombières. The combination of different methods to determine (pseudo-)total element concentrations, sequential extractions and quantitative mineralogical analysis provided detailed information on the reactivity of minerals in the waste, as well as the associated metal(loid) release under different experimental conditions. Lithium borate (LiBO2) fusion was not suited to determine total metal(loid) concentrations in the investigated mine waste samples, due to the incomplete dissolution of the samples, and the volatilization of As and Cd during the fusion. Because some elements were below detection limit of X-ray fluorescence spectrometry (e.g. Cd), aqua regia digestion was useful to complement the chemical sample characterization, bearing in mind that only pseudo-total concentrations could be determined. Galena (PbS) and its alteration products cerussite and anglesite (PbSO4) were the main lead minerals associated with the mining waste. Because of the high cerussite (PbCO3) content of the investigated samples (2-5 wt%), Pb shows the highest potential for recovery from the mining waste, but it also poses the highest environmental and human health risk. Zinc minerals showed a lower reactivity towards the BCR sequential extraction (sphalerite, ZnS) or were less abundant (willemite, Zn2SiO4). Quantitative XRD analysis allowed for better evaluation of the incomplete dissolution of some minerals, improving the interpretation of the sequential extraction results.

The Vijenac limestone quarry, near Tuzla in Bosnia and Herzegovina, is composed of carbonate rocks locally embedding tectonically disturbed siltite and sandstone with Fe-Mn concretions. The quarry itself represents a part of Dinaric overstep sequences (the Pogari Formation) unconformably overlying ophiolite mélange and ophiolite trust-scheets. Petrographic, chemical and mineralogical analyses had shown that the concretions may be divided into two types: (i) Mn-rich concretions with 17 wt.% of Mn and compact texture and (ii) Mn-poor with 8 wt.% of Mn and porous texture. The amount of Ca, Fe and Mg in both concretion types are similar. Nickel and Cr positively correlate with Fe and Mn, respectively. According to petrographic and mineralogical analyses, concretions are composed of calcite, dolomite, hematite, todorokite and takanelite. Petrographic study con rmed the development of concretions within three stages including two generations of calcite. Studied concretions are formed within consolidated sandstones inheriting their sedimentary textures-therefore a late diagenetic process is assumed.