The possibility of metal removal from the real acid mine drainage (AMD) in the area of copper ore mines in the southeast Serbia, was investigated through a combination of neutralization and adsorption methods. This approach of metal removal from AMD includes a two-step neutralization method in the first phase, aiming to separate metals as sludge. The results of laboratory test revealed that more than 99 mass % of Fe is removed up to pH 4 and more than 99 mass % of Cu up to pH 7. Based on the results obtained in laboratory conditions, a test on a semi industrial plant was carried out. The two-step neutralization separately removed Fe and Cu at pH 4 and 7, respectively. Especially, the obtained sludge at pH 7 included 1.24 mass % of Cu, much higher than usual Cu ore. Chitosan was applied for dissolved Mn removal from treated AMD. After 24 h incubation, 70 mass % of Mn is removed from the treated AMD at pH 7.4. Mn concentration was reduced from approx. 35 mg L⁻¹ to 5 mg L⁻¹. These results have indicated that a combination of neutralization and adsorption methods could be used effectively for metal removal from real AMD.

There are many sources to increase value in an integrated mining–metallurgy context. The optimal strategy for concentration of minerals from the ore is one of these sources. The elements of mining-metallurgy operations from resources, infrastructure, mining site, processing, and metallurgy are mutually dependent, and reinforce and interact positively with each other to generate a combined value greater than the sum of their individual contributions. Bioleaching technology is an alternative processing technology for treatment of low-grade sulphide ore, and its application contributes to the achievement of better economic results than the conventional pyrometallurgical technology. This work presents the application of bioleaching technology in laboratory conditions for metal extraction from the polymetallic deposit Tenka in East Serbia, belonging to the company Serbia Zijin Bor Copper Doo (formerly the Mining Smelter Basin Bor Group). Bioleaching of sulphide polymetallic raw material is performed by chemolithoautotrophic microorganisms. Applying the bioleaching technology, the achieved recoveries of metals from the polymetallic ore are as follows: Cu 90%, Au 90%, Ag 80%, Zn 72% and Pb 90%. The calculated values for Net Present Value (NPV) and Internal Rate of Return (IRR) are $ 21.927 million and 12.55%, respectively.

The processing of zinc ore using hydrometallurgical methods leads to the formation and accumulation of a by-product called jarosite, which contains concentrated precious metals. In this study, we propose the recovery of In and its separation from Cu, Zn, Fe, Pb, and Ag. This study also presents a proposal for a new technological procedure for jarosite treatment. First we roasted the jarosite, and then the calcine collected was leached in water. The leaching extraction values obtained for Cu, Zn, Fe, and In were 91.07%, 91.97%, 9.60%, and 100.0%, respectively. Following the leaching of the roasted material in water, Pb, Ag, and most of the Fe obtained remained in the solid residue. The leaching solution was treated further by a precipitation process using NaOH, where In and Fe were precipitated and consequently separated from Cu and Zn. The In (OH)₃ and Fe(OH)₃ precipitates were dissolved further in a diluted H₂SO₄ solution, and then the cementation of In with Al was performed. We used HCl acid to remove Al from the In, after which unwrought In was obtained.

The increased exploitation of ores leads to the generation of mining waste, which has a negative impact on the environment and human health. For this reason, it is necessary to take care of it in an adequate way by applying some of the possible treatments. In addition to protecting the environment by applying appropriate treatment, there is also the possibility of making a profit by valorizing useful elements from mining waste. In order to choose the most adequate treatment, it is necessary to perform the characterization of mining waste. This paper contains a detailed characterization of the flotation tailings deposited at the Old Flotation Tailings in eastern Serbia, originating from copper ore processing. Characterization includes physico-chemical analysis, polarizing microscope analysis, X-ray Diffraction analysis (XRD) and Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) analysis analysis. The obtained results indicate that the investigated flotation tailings can be used as a secondary raw material for metal recovery, in this case primarily copper (whose content is about 0.24%), gold (with a content of about 0.43 ppm) and silver (with a content of about 1.7 ppm). Considering that the content of valuable elements is quite low, it is suggested to apply hydrometallurgical treatment for their recovery.

The present paper describes the technological solution for obtaining Cu, Zn, Pb, and Ag from jarosite waste raw material, with its simultaneous separation from In and Fe. By roasting at low temperatures, iron was transformed from the Fe₂(SO₄)₃ form into Fe₂O₃, which is insoluble in water and slightly soluble in acid. Copper sulfate and zinc sulfate are present in jarosite as sulfates. During temperature roasting, the copper and zinc were still in the form of CuSO₄ and ZnSO₄, i.e., they were easily dissolved in water. This procedure led to good selectivity of Cu and Zn compared to Fe. After water leaching, PbSO₄ and Ag₂SO₄ remained in the solid residue. By treating jarosite with a content of 0.7% Cu, 5.39% Zn, and 5.68% Pb, products of commercial quality were obtained. By roasting jarosite in an electric furnace and leaching the roasted sample in water, leaching degrees of 91.07%, 91.97%, and 9.60% were obtained for Cu, Zn, and Fe, respectively. Using 1 M NaOH in the leaching solution, 99.93% Fe was precipitated to pH = 4. Cu in the form of CuSO₄ was further treated by cementation with Zn, after which cement copper was obtained as a commercial product. Zn in the form of ZnSO₄ was further treated by precipitation with Na₂CO₃ to obtain ZnCO₃ concentrate of commercial grade. The total recovery of Pb and Ag, which were treated by chloride leaching, was 96.05% and 87.5%, respectively. The resulting NaPbCl₃ solution was further treated with Na₂CO₃ solution, whereby PbCO₃ was obtained as a commercial product. The produced PbCO₃ could be further subjected to roasting to obtain soluble PbO. In these investigations, PbCO₃ was smelted where a Pb anode was obtained; this was electrolytically refined to a Pb cathode. The proposed process does not pollute the environment with As and Cd.

This paper presents the results of research on the corrosion behavior of brass CuZn42 in an acidic environment, in the presence of copper ions. Based on the recorded anodic polarization curves, it was concluded that as the concentration of copper ions in the tested solution increases, the corrosion current densities also increase. This is reflected in the occurrence of the decinking process of brass, during which zinc is deposited on its surface, while the remaining porous copper stays within the brass mass.