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Item Review of material and process parameters in the production of drawn SnPb wire(Fakultet Tehničkih nauka, Kosovska Mitrovica, 2025) Kovačević, Avram; Stamenković, Uroš; Nedeljković, MilanThe aim of this study is to review pre-processing parameters prior to forming SnPb wire through the cold drawing process. The research focuses on different factors such as chemical composition and homogenity, oxide content, and the initial mechanical properties of starting materials prior to plastic deformation. Special attention is given to the selection of appropriate SnPb alloy ratios — primarily Sn60Pb40 and Sn63Pb37, due to their good mechanical, electrical and thermal properties. Further analysis of pre-processing steps such as surface cleaning, tool settings and mechanical processing regime is conducted to determine their effect on drawability, grain boundary behavior, and resistance to fracture during multi-pass drawing. All relevant parameters were analyzed in the context of minimizing processing defects such as wire breakage, ovality, and surface roughness. It is concluded that chemical homogenity and surface oxides play an important role in achieving a balance between ductility and strength during the processing. This is particularly important, given that the drawing process induces a significant amount of internal stresses. The chemical composition, especially the Sn-Pb ratio, has a major effect on the recrystallization temperature, which is a key factor defining the efficiency of the further plastic deformation. The applied thermomechanical treatment regime plays a crucial role in controlling microstructural evolution and stable drawing performance under industrial-scale production. This study contributes to improving production performance, ensuring high quality tolerances of the final products.Item Influence of organic compound structure on brass corrosion inhibition efficiency(University of Belgrade, Technical Faculty in Bor, 2025) Cvetković, Aleksandar; Petrović Mihajlović, Marija; Tasić, Zaklina; Radovanović, Milan B.; Simonović, Ana; Nedelkovski, VladanIn this study the influence of organic compounds with different structures on the inhibition of brass corrosion in sodium chloride solutions of 0.9%, 2% and 3.5% is investigated. The experimental work includes the evaluation of the inhibition efficiency of 2-mercapto-1-methylimidazole (MMI), 2-amino-5-ethyl-1,3,4-thiadiazole (AETDA) and N-acetyl-L-leucine at various concentrations using electrochemical methods, including open circuit potential (OCP), cyclic voltammetry (CV), and potentiodynamic measurements (PD). The results show that all tested inhibitors reduce the corrosion currents and potentials, with the highest efficiency observed in solutions with the lowest sodium chloride concentration of 0.9%, where AETDA exhibited the highest inhibition efficiency of 92.93%, while MMI showed an efficiency of 88.78% at the same inhibitor concentration of 10-2 M. Compared to AETDA and MMI, N-acetyl-L-leucine at a concentration of 10-3 M showed the lowest inhibition efficiency of 44.21%, while AETDA and MMI achieved inhibition efficiencies of 76.12% and 72.16%, respectively. Adsorption isotherms were used to evaluate the binding mechanisms of inhibitors on the brass surface, and physisorption was found to be the most likely mechanism for all tested compounds. These findings provide insight into the potential application of the investigated inhibitors to prevent brass corrosion under corrosive conditions.Item Waste to resource transformation: innovative approaches to recycling cathode materials from lithium-ion batteries(University of Belgrade, Technical Faculty in Bor, 2025) Cvetković, Aleksandar; Nedelkovski, Vladan; Medić, Dragana; Stanković, Sonja; Tasić, Zaklina; Radovanović, Milan B.; Milić, SnežanaThe surging use of lithium-ion batteries (LIBs) has precipitated an imperative for sustainable recycling practices to recover valuable cathode materials, ensuring environmental stewardship and resource efficiency. This review delves into recent innovations in cathode material recycling from LIBs, focusing on methodologies that not only reclaim materials but also restore their functionality for reuse. Highlighted are cutting-edge techniques such as an electrochemical relithiation process, which rejuvenates spent cathode materials to equal the performance of new ones. At the forefront of these sustainable practices is the concept of direct regeneration via direct recycling, offering an economically viable and environmentally friendly approach to mend degraded cathodes. Such progress signals a shift away from conventional metallurgical methods toward intelligent regeneration, representing a significant step forward in the sustainable recycling of LIBs. This review provides a brief analysis of these novel recycling processes, illustrating their ability to transform spent batteries into valuable resources, mitigate environmental harm, and foster a circular economy within the realm of energy storage.Item Investigation of the copper and iron behavior during the leaching of flotation tailings in an ionic liquid solution [bmim][HSO4](Springer, 2025) Marilović, Dragana; Bogdanović, Grozdanka; Stevanović, Zoran; Petrović, Sanja J.; Sokić, MiroslavA new sustainable leaching system with low reagents and energy consumption is a major step forward in the recovery of metals from secondary raw materials. Sulfuric acid is the most commonly used leaching agent for flotation tailings, primarily due to its high efficiency, low cost, and availability. However, ionic liquids have recently attracted increasing attention as a more sustainable and selective alternative to conventional acids, due to their characteristics such as low volatility, chemical stability and possibility for regeneration. This study investigated the leaching behavior of Cu and Fe from flotation tailings with the ionic liquid solution [bmim][HSO4] and sulfuric acid solution (H2SO4) to compare the effect of these reagents on the extraction efficiency of Cu and Fe ions. The leaching parameters, such as ionic liquid concentration in the presence and absence of the oxidant, stirring speed, solid-liquid ratio, and oxidant concentration on the flotation tailings leaching, were investigated. The maximum copper extraction of 91.55% was achieved under the following conditions: solid/liquid ratio 1:20, 0.1 mol/dm3 concentration of ionic liquid, 1.5 mol/dm3 H2O2 concentration, stirring speed 400 rpm at ambient temperature within 120 min of leaching. Under the same conditions, the iron leaching degree was around 24%. Based on the copper leaching degree and content of copper oxide in the initial sample, it is assumed that Cu is also leached from sulfide minerals.Item The determinants of electric and hybrid vehicle adoption - a perspective from Serbia(University of Belgrade, Technical faculty in Bor, 2025) Mitić, Petar; Kojić, Milena ; Hanić, Aida; Fedajev, Aleksandra; Radulescu, Magdalena; Dembińska, IzabelaThis study investigates the factors influencing the intention to purchase electric and hybrid vehicles in Serbia. It draws upon socio-demographic characteristics, social influence, environmental concerns, and policy measures to gain a nuanced understanding of the complexities of adopting sustainable transportation alternatives in Serbia. Using descriptive and inferential statistics, decision tree analysis, and logistic regression enabled a rigorous examination of the determinants influencing attitudes and intentions toward electric and hybrid vehicles (EHVs). The findings emphasized the importance of positive evaluation from influential individuals and the introduction of higher taxes on more polluting vehicles as important factors that impact electric and hybrid vehicle adoption according to all three applied methods. In addition to these factors, the results from the two applied methods further highlight the significance of household income, the positive societal perception of EHVs, and the belief that EHVs contribute to reduced pollution. Since age, residence, education level, and household size do not emerge as significant factors influencing respondents' intention to purchase EHVs and all remaining factors appear to be relevant according to only one of the applied methods, the focus should be placed on the factors identified as significant by either two or all three methods. Such results provide a solid basis for policy recommendations in Serbia to promote electric and hybrid vehicles adoption.Item Comparative study of the effect of particle size on flotation kinetics of raw and waste coal(MDPI, 2025) Sokolović, Jovica; Djolović, Ivana; Tanikić, Dejan; Štirbanović, Zoran; Ilic, IvanaThis study examines the influence of particle size on the flotation kinetics parameters of both raw and waste fine coal originating from the anthracite mine “Vrška Čuka”, Serbia. Flotation kinetics modeling was performed using MATLAB for nonlinear regression analysis, based on coal flotation test data. The correlation between total combustible recovery and flotation time was determined using the following models: Classical, Klimpel, Kelsall, Modified Kelsall, and Fully Mixed. The coefficients of determination range from 0.9724 (the Klimpel model) to 1 (the modified Kelsall model) for raw coal and from 0.8609 (the Klimpel model) to 0.9981 (the modified Kelsall model) for waste coal. Although both the Classical and Modified Kelsall models demonstrated a good correlation with the experimental data, the Modified Kelsall model provided a slightly better fit. The maximum values of the flotation rate constant (k) for both coals were obtained for the particle size-class (−0.1 + 0.053) mm for the Classical model and (−0.2 + 0.1) mm for the modified Kelsall model. The relation between flotation kinetics constant (k) and average particle size value (dsr) was estimated for the Classical model and the modified Kelsall model. It was observed that the flotation kinetics constant (k) for coal particle size could be predicted satisfactorily.Item Comparative analysis on washability indices of anthracite coal by using MCDM methods(Wroclaw University of Science and Technology, Poland, 2025) Sokolović, Jovica; Stanujkić, Dragisa; Štirbanović, Zoran; Ilić, IvanaThis paper presents the results of the Multi-Criteria Decision Making (MCDM) methods for determining the optimal separation density in the gravity separation of anthracite coal, and also suggests an appropriate MCDM model for this purpose. Five separation densities were selected as the output and seven coal washability indices were used as the input based on the washability results of coal. The SAW, TOPSIS, WASPAS, WISP, and CoCoSo methods were used in this study. The evaluation indices of the five methods were averaged as a new index. Finally, alternative A4 (i.e., the optimal separation density is 1650 kg/m3) was selected as the final separation density.Item Behavior of zinc, calcium and iron in the two-stage leaching process of the EAF dust(University of Belgrade - Technical Faculty in Bor, 2025) Trifunović, Vanja; Milić, Snežana; Avramović, Ljiljana; Božić, Dragana; Avramović, ZoranThe treatment of the EAF dust was carried out by applying the leaching process in two technological stages in order to selectively separate certain components from the EAF dust. In the first stage, a pre-treatment was performed to selectively remove water-soluble components from the original EAF dust sample, while in the second stage, zinc was selectively separated from the resulting solid residue by acid leaching. In the second stage of the leaching process, the influence of the acid leaching process time on the zinc, calcium and iron leaching rates were investigated. Selective zinc recovery from the EAF dust was achieved with the following optimal parameters of the acid leaching process: leaching reagent 1.0 M solution of H2SO4, ambient temperature, S:L ratio =1:4, time 10 min and stirring speed 500 rpm. The zinc leaching rate in the second leaching stage was 60.74%, while the Ca and Fe leaching rates were significantly lower and amounted to 12.18% and <0.01%, respectively.Item The effect of particle size on the flotation kinetics of raw and waste coal(University of Belgrade, Technical Faculty in Bor, 2025) Sokolović, Jovica; Djolović, Ivana; Tanikić, Dejan; Štirbanović, Zoran; Ilić, IvanaThis paper investigates the effect of particle size on the flotation kinetics parameters of raw and waste fine coal from anthracite mine "Vrška Čuka, Serbia. Based on batch flotation test data of coal, non-linear fitting was conducted by using MatLab for modeling first order flotation kinetics. The cumulative combustible recovery against flotation time were correlated using the Classical model. The coefficient of determination (r2) values of the proposed model were from 0.9904 to 0.9998 for raw coal and from 0.9555 to 0.9980 for waste coal. The maximum values of the flotation rate constant (k) for both coals were obtained for the particle size fractions (-0.1+0.053) mm. The relation between flotation kinetics constant (k) with particle size (dsr) was estimated through equations presented in the paper (Eq. 3 and 4).Item Prediction of results of floatation process using artificial neural networks(University of Belgrade, Technical Faculty in Bor, 2025) Trumić, Maja; Balanović, Katarina; Gavrilović, TamaraIn this paper, the use of artificial neural networks in the flotation process is presented and analyzed. Apart from utilization of flotation in the mineral processing, deinking flotation is used for separation of ink particles from the cellulose fibers. The time of deinking flotation, pH value, reagents such as oleic acid, oleic acid with CaCl2, oleic acid with AlCl2 as well as concentration of reagents were used as input for the network. The recovery of toner particles in froth was used as output data for the network. The neural network demonstrated high correlation coefficients during training (0.97), validation (0.96), and testing (0.94), and subsequent accuracy testing confirmed these results.Item Influence of hidden neuron number on the performance of ANN models applied to deinking flotation data(University of Belgrade - Technical Faculty in Bor, 2025) Balanović, Katarina; Trumić, Maja; Gavrilović, TamaraIn this paper, the influence of the optimal number of neurons in an artificial neural network model, applied to data obtained from deinking flotation is presented and analyzed. The results indicate that when a wellperforming model is selected, it is not necessary to search for the optimal number of hidden neurons. However, when the applied model does not yield satisfactory results, determining the optimal number of neurons becomes essential.Item Towards safer mines: Analyzing occupational health and safety perceptions and injury patterns in Serbian underground mining(IOS Press, SAGE Publications, 2025) Ivaz, Jelena; Fedajev, Aleksandra; Petrović, Dejan; Stojadinović, Saša; Zlatanović, Dragan; Stojković, Pavle; Stajić, Milan; Radovanović, MladenBackground: Mining is a high-risk sector, particularly in underground environments, where workers face daily hazards. This research evaluates workplace safety perceptions in Serbian underground coal mines, ranking workers by education, age, and job role, while incorporating injury data to provide a comprehensive assessment of safety across different worker groups. Objective: This study is aimed at analyses of the correlation between occupational health and safety (OHS) perceptions and the injury index across different worker groups, to identify improvement opportunities and propose targeted measures for enhancing OHS practices. Methods: The PROMETHEE II method categorized workers based on production units, qualifications, and age, focusing on criteria like protective equipment, work conditions, risk awareness, management, work organization, and training. The entropy method provided objective weightings for these criteria, allowing for comparison with injury index rankings to establish priorities for improvement. Results: Štavalj and Vrška Čuka ranked highest in OHS perception. Workers with MSc/Dr qualifications displayed heightened awareness of safety, while those aged 56 to 65 exhibited the best understanding of health and safety. Spearman rank correlation coefficients revealed a strong negative correlation (−0.796) for production units, a strong positive correlation (0.70) for qualifications, and a very strong positive correlation (0.90) for age concerning PROMETHEE II rankings and injury index indicators. Conclusions: The disparities between worker perception rankings and injury index rankings suggest opportunities for targeted safety improvements and enhanced training protocols.Item Anode nanomaterial recovered from spent batteries for peroxide-assisted crystal violet photocatalytic degradation(University of Belgrade, Technical Faculty in Bor, 2025) Nedelkovski, Vladan; Medić, Dragana; Cvetković, Aleksandar; Stanković, Sonja; Tasić, Žaklina; Radovanović, Milan; Milić, SnežanaThis study explores the photocatalytic degradation of Crystal Violet (CV) using anode nanomaterials recovered from spent nickel-metal hydride (NiMH) batteries, activated by hydrogen peroxide (H₂O₂). The research focuses on the potential application of recycled perovskite-based materials, such as Lanthanum Cobalt Oxide (LaCoO₃), Nickel Oxide (NiO), and Cerium Dioxide (CeO₂), for the efficient removal of organic dyes from textile industry wastewater. Structural characterization via X-ray diffraction (XRD) confirmed the presence of crystalline phases with high crystallinity, essential for photocatalytic activity. Photocatalytic experiments were conducted under UV-A light (λ = 395 nm) at pH 5.5, demonstrating a degradation efficiency of 99.52% within 60 minutes. The reaction followed pseudo-first-order kinetics, with a significant increase in efficiency over time. These findings highlight the potential of using recycled battery materials as sustainable and effective photocatalysts for wastewater treatment, offering a promising solution to mitigate environmental contamination caused by synthetic dyes and other persistent organic pollutants.Item Carbon paste electrodes and ZnO/CPE sensors: a short review(The Academy of Applied Studies Polytechnic, Belgrade, 2025) Cvetković, Aleksandar; Tasić, Zaklina; Petrović Mihajlović, Marija; Radovanović, Milan B.; Simonović, Ana; Antonijević, Milan; Milić, SnežanaThis paper represents a short review of electrochemical sensors based on carbon materials, with a focus on carbon paste electrodes (CPEs) as signal detectors, and the pivot placed on the preparation steps, where CPEs stand out because of their easy preparation, regenerability, and high flexibility for modification. Incorporation of zinc oxide (ZnO) nanoparticles into CPE matrices enhances sensor performance by enlarging the active surface area, reducing charge-transfer resistance, and improving electron transfer kinetics. ZnO/CPE electrodes have demonstrated high sensitivity and selectivity for the detection of pharmaceuticals, food additives, dyes, and biologically active compounds. Their preparation is straightforward, typically involving co-precipitation synthesis of ZnO nanoparticles followed by mixing with graphite powder and binder. Combined electrochemical and morphological characterization provides insights into the structural and functional improvements achieved by ZnO modification, confirming their potential for advanced electrochemical sensing applications.Item Advances in photocatalytic degradation of crystal violet using ZnO-based nanomaterials and optimization possibilities: a review(MDPI, 2025) Nedelkovski, Vladan; Radovanović, Milan; Antonijević, MilanThe photocatalytic degradation of Crystal Violet (CV) using ZnO-based nanomaterials presents a promising solution for addressing water pollution caused by synthetic dyes. This review highlights the exceptional efficiency of ZnO and its modified forms—such as doped, composite, and heterostructured variants—in degrading CV under both ultraviolet (UV) and solar irradiation. Key advancements include strategic bandgap engineering through doping (e.g., Cd, Mn, Co), innovative heterojunction designs (e.g., n-ZnO/p-Cu2O, g-C3N4/ZnO), and composite formations with graphene oxide, which collectively enhance visible-light absorption and minimize charge recombination. The degradation mechanism, primarily driven by hydroxyl and superoxide radicals, leads to the complete mineralization of CV into non-toxic byproducts. Furthermore, this review emphasizes the emerging role of Artificial Neural Networks (ANNs) as superior tools for optimizing degradation parameters, demonstrating higher predictive accuracy and scalability compared to traditional methods like Response Surface Methodology (RSM). Potential operational challenges and future directions—including machine learning-driven optimization, real-effluent testing potential, and the development of solar-active catalysts—are further discussed. This work not only consolidates recent breakthroughs in ZnO-based photocatalysis but also provides a forward-looking perspective on sustainable wastewater treatment strategies.Item Leaching of flotation tailings with a sulfuric acid and an ionic liquid in the presence of hydrogen peroxide(Mining and Metallurgy Institute Bor, 2024) Marilović, Dragana; Bogdanovic, GrozdankaThis study focuses on leaching of flotation tailings with sulphuric acid (H2SO4) and ionic liquid 1-butyl-3-methyl-imidazolium hydrogen sulfate ([bmim]HSO4) in the presence of hydrogen peroxide (H2O2). Reagent concentrations of 0.01 mol/dm3 and 0.05 mol/dm3 in the present of 0.1 mol/dm3 H2O2 were tested. When leaching with sulfuric acid in the presence of oxidants, the leaching degree of copper was 80.85% (for 0.01 mol/dm3) and 82.24 (for 0.05 mol/dm3). When flotation tailings were leached in an ionic liquid solution with the same concentrations in the present of oxidants, the leaching degree of copper was 72.56% and 83.14 % for 0.01 and 0.05 mol/dm3, respectively. The results showed that the maximum dissolution of iron of 3.65% in the presence of hydrogen peroxide was attained with 0.05 mol/dm3 H2SO4 after 120 min of the reaction and 1 % in the 0.05 mol/dm3 solution of the ionic liquid [bmim]HSO4 after 120 min of the reaction.Item Conflict management styles in project-based organisations: relation to demographic factors(University of Belgrade, Technical Faculty in Bor, 2025) Radić, Aleksandra ; Milijić, NenadDuring the project realization, disagreements arise and cannot be avoided. Project complexity, various participants, stakeholders' interests, task requirements, and tight project deadlines create an environment for conflict issues. Every individual engaged in the project responds to conflict differently and has a distinct conflict management strategy. Therefore, this research aims to get deeper insights into conflict management styles’ differences in specific demographic characteristics. Empirical research was conducted to obtain this study's objective. A total sample of 114 employees from project-based organizations operating in the Republic of Serbia was collected. The findings of the ANOVA test revealed that participants’ responses differed in terms of age, work experience, and project type. Findings provide valuable insights by examining differences in conflict management styles and identifying behavioral patterns and variations based on demographic factors.Item From waste to resource: leaching metals from flotation tailings at the “Rudnik” mine for sustainable development(The Academy of Applied Studies Polytechnic, Belgrade, 2025) Bogdanović, Grozdanka; Radulović, Dragan; Marilović, Dragana; Stojanović, Jovica; Petrović, Sanja J.; Simić, VladimirModern industries engaged in the design and development of high-technology products are highly dependent on the availability of critical materials. Due to the increasingly rapid depletion of primary raw materials, there is growing interest in processing secondary raw materials, such as mining waste and flotation tailings. In this study, leaching experiments were conducted on a sample of flotation tailings from the Rudnik mine (Serbia) containing copper (0.081%), lead (0.132%), zinc (0.510%) and iron (6.88%). The influence of hydrogen peroxide concentration in sulfuric acid solution on metal leaching was examined. It was established that in the system of sulfuric acid (1 mol/dm³ H2SO4) and hydrogen peroxide (H2O2, 1–3 mol/dm³), the highest leaching of metals was achieved at the lowest concentration of hydrogen peroxide over 120 minutes, amounting to 81.97% Cu, 48.84% Fe, and 45.58% Pb. Increasing the concentration of hydrogen peroxide (1–3 mol/dm³) leads to a decrease in the degree of leaching of the tested metals, except for Zn. The highest zinc extraction was 97.72% (2.0 mol/dm³ H2O2). The obtained leaching values are higher compared to leaching flotation tailings with sulfuric acid solution.Item Influence of oxidant concentration on the leaching of flotation tailings in acidic medium(Association of Metallurgical Engineers of Serbia (AMES), 2025) Bogdanović, Grozdanka; Marilović, Dragana; Nedelkovski, Vladan; Stevanović, Zoran; Sokić, MiroslavThe reprocessing of sulphide minerals in flotation tailings is an attractive option for sustainable mine waste management. Conventional mineral processing methods often encounter difficulties when processing tailings, mainly due to factors such as particle size and surface oxidation of minerals. In most cases, copper is extracted from such raw materials using leaching processes. The paper presents an investigation of the leaching of flotation tailings using 0.1 mol/dm3 H2SO4 solution in which ferric ions and hydrogen peroxide play the role of oxidants. The influence of oxidant concentration on the leaching of copper and iron was investigated. It was found that the addition of ferric ions influenced the leaching of copper, with approximately 79% of copper was leached with 5 g/dm3 of Fe(III) ions. It has also been shown that the concentration of hydrogen peroxide affects the leaching of copper and iron. The total copper extraction of 85.31% and iron extraction of 7.66% were achieved with 0.3 mol/dm3 H2O2 during 120 minutes of reaction time.Item Effect of temperature on the leaching copper from flotation tailings with ionic liquid(University of Belgrade, Technical Faculty in Bor, 2025) Marilović, Dragana; Stanković, Sonja; Bogdanović, GrozdankaFlotation tailings of copper ore contain a high concentration of valuable metals such as copper, gold and silver. Minerals are mainly found in the form of oxides and less in the form of sulfides that have not been separated by flotation concentration. Recovering these valuable resources would reduce the environmental impact and increase the economic benefits. Compared to sulphide ores and minerals, the presence of oxidising agents is generally not required for the leaching of raw materials rich in oxides. This paper presents the results of the study the influence of temperature on the copper leaching degree from flotation tailings by ionic liquid solutions of different concentrations. Based on the results obtained, it was found that increasing the leaching temperature significantly affects the leaching efficiency. After 120 minutes of leaching at 70°C, a copper leaching degree of 99.7% was achieved at lower ionic liquid concentration than at ambient temperature.