Copper Ore Processing Research Articles

INNOVATIVE METHODS FOR PROCESSING COPPER ORES IN KAZAKHSTAN: A COMPREHENSIVE APPROACH TO ENHANCING THE EFFICIENCY OF VALUABLE COMPONENT EXTRACTION

This article presents an innovative approach to processing copper ore from one of the deposits in Kazakhstan, aimed at enhancing the efficiency of copper extraction from materials with a complex mineral composition. The described methodology includes several key stages: comprehensive analysis of the ore's material composition, gravity and flotation beneficiation, as well as hydrometallurgical processes. During the study, the ores underwent preliminary preparation, including crushing and grinding to the required fineness. Experiments on gravity and flotation beneficiation demonstrated that optimizing the parameters of these processes significantly increases the yield of copper concentrate. Additionally, sulfuric acid leaching conducted showed high efficiency in extracting copper from the ground ore. The research results confirm that a comprehensive approach to copper ore processing ensures high efficiency in extracting valuable components and opens up prospects for the sustainable and economically viable utilization of complex copper ores

Flotation Tailings from Cu-Au Mining (Bor, Serbia) as a Potential Secondary Raw Material for Valuable Metals Recovery

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.

Obtention of Suitable Pregnant Leach Solution (PLS) for Copper Solvent Extraction Plants from Copper Concentrate Using Hydrogen Peroxide and Iodine in a Sulfuric Acid–Chloride Medium

Copper leaching presents an environmentally friendly alternative to traditional sulfide ore processing methods. This study investigates an efficient leaching process for copper concentrate, utilizing a solution of sulfuric acid (H2SO4) and potassium iodide (KI) in a chloride medium (NaCl), enhanced by hydrogen peroxide (H2O2) at room temperature. A significant aspect of this research was optimizing the KI concentration to minimize iodide sublimation into iodine gas (I2). Through the experimental design, the optimal dosages of reagents were determined, leading to maximized copper extraction of approximately 27% in 45 min of testing at room temperature. The results showed that it is possible to obtain a suitable pregnant leach solution (PLS) (i.e., in the range of 3 to 8 g/L of Cu) for treatment in available copper solvent extraction (SX) plants with a cost of less than 4.5 USD/t Cu, according to the economic analysis carried out. The results of this study determine the most effective operational conditions for leaching and ensure a suitable PLS for SX plants in a cost-effective and environmentally friendly manner. This approach could significantly contribute to more sustainable practices in the mining and processing of copper ores.

Enhanced leaching of copper from refractory oxidized copper ore by calcium fluoride: Behavior and mechanism

The Luanshya area of Zambia is rich in copper oxide resources. However, copper mainly exists in biotite and phlogopite, which presents challenges for efficient extraction. To improve the leaching rate of copper from these ores, local hydrometallurgical plants use heating and stirring; however, the leaching rate is not high. To address the issue in this work, CaF2 was introduced as a leaching aid, and the effects of various parameters on leaching were systematically studied. The results revealed that when the dosage of CaF2 is 5wt% of raw ore mass, the dosage of sulfuric acid is 120 kg/t, the leaching temperature is 60 °C, and the leaching time is 200 min with a slurry concentration of 30wt%, the leaching rate of copper can reach 80.44%. Compared with regular heating stirring acid leaching, the copper leaching rate was found to increase by 8.76%, while the leaching temperature decreased by 5 °C and the leaching time shortened by 40 min. The results of the HSC Chemistry 6.0 thermodynamic calculations and mechanism analysis indicated that F can promote the fracture of Si–O and Al–O bonds in the crystal structure of biotite and phlogopite in sulfuric acid solution, enabling a direct reaction between the acid and copper. The proposed method can be applied not only to the treatment of cupriferous mica ores but also to the processing of other copper ores. This process is more efficient and cost-effective than the regular heating–stirring acid leaching process.

Assessment of Concrete Hollow Blocks Incorporating Polyethylene Terephthalate (PRT) and Copper Slag as a Commercial Concrete Alternative

The increasing demand for durable and sustainable concrete driven by population growth and urbanization, highlights the need for an environmentally friendly alternative to traditional concrete, by innovating and recycling the top waste made by industries, given the country’s vulnerability to natural disasters and the environmental impact of concrete production. Polyethylene Terephthalate (PET) waste accounts for up to 13.9% of all waste plastics, posing a serious hazard to the environment and ecology both on land and in oceans (Ye et al., 2023); similarly, copper slag, a by-product of the smelting and processing of copper ore, is generated at a rate of 2.2 tons per ton of copper produced, leading to an annual figure of 24.6 million tons of slag (Gabasiane et al., 2021). With this, researchers are still finding ways to search for an alternative to lessen the environmental waste whilst contributing to the construction industry. Subsequently, this study aims to test the viability and effectiveness of Polyethylene Terephthalate and Copper Slag-induced concrete hollow blocks as an alternative to traditional commercial concrete hollow blocks. The researchers used a Post-Test Only Controlled Group Design, providing a complete understanding of their effect on concrete performance. By utilizing purposive sampling, the researchers were able to select shredded PET as their chosen samples. The raw data from the test results of varying ratios were treated using ANOVA. In terms of compressive strength and water absorption percentage, the 30-70 ratio emerged as the most durable, while in density, the commercial concrete displayed the highest amount. Upon comparative analysis, the results from the data treatment shows a significant difference in incorporating Polyethylene Terephthalate and Copper slag into concrete, specifically the 30% PET and Copper slag to 70% cement ratio, therefore rejecting the null hypothesis. It is advised to explore more ratios to accommodate different construction demands and have a minimum curing time of 28 days before testing the qualities of the said concrete hollow blocks.

Properties governing the flow of solution through crushed ore for heap leaching: Part III – Low-permeability ores

Heap leaching is used extensively for the processing of low-grade copper and gold ores. If the ore has low permeability, it may lead to underperformance or even project failure. Poor permeability is caused by a high fines content, resulting in a high steady-state moisture hold-up which causes the bed to operate close to saturation. The problem of low permeability can be addressed by either desliming (removal of the fines by wet screening), or by agglomeration (binding the fines together) with a cementitious binder. Fines removal by desliming is shown to reduce the steady-state moisture hold-up, resulting in the bed operating further away from saturation and increasing the maximum solution application rate. Agglomeration with Ordinary Portland Cement modified with additives resulted in fine particles binding together as lumps or coatings onto coarser rocks. These bonds were not destroyed after prolonged exposure to dilute sulphuric acid, due to the pozzolanic properties of the additives (e.g. fly ash), which cause cementitious Ca-bonds to be substituted with more stable Al- or Mg-bonds. Agglomeration with cementitious binder was also found to reduce slumping in leach column tests. This resulted in a higher bed porosity, higher limits on the solution application rate and higher copper dissolution rates. Agglomeration with modified cement may provide a novel, cost-effective method for the treatment of low-permeability ores in acid medium (e.g. copper, uranium and nickel), since cement agglomeration has only been applied commercially in alkali medium (e.g. cyanide solutions for gold ores) to date. Desliming is less attractive due to the high losses of the target metal to the fines.

Flotation processing of gold-bearing porphyry copper ores from the Republic of Uzbekistan deposits optimized through the use of advanced russia-made collecting agents

Flotation processing of gold-bearing porphyry copper ores from the Republic of Uzbekistan deposits optimized through the use of advanced russia-made collecting agents

Effectiveness of Copper Minerals Liberation from the Gangue through Application of HRC Press in Copper Ore Processing Circuits

The article concerns investigations over benefits of application of HRC devices into sulphide copper ore processing plant. High pressure comminution appears to be very effective technology in hard ore processing circuits, especially in terms of energy consumption. This can be particularly observed in downstream grinding and beneficiation operations. A series of pilot-scale crushing tests in HRC roller press for various levels of operating pressure, were performed. HRC crushing effectiveness along with downstream grinding process course for each crushing product were also under analysis. The investigations were supplemented by analysis of flotation process effectiveness and impact of the process of high-pressure comminution on environment (dust emission). The results of investigation show that operating pressure level influences the obtained comminution results (comminution degree, yield of finest particle size fractions). The grinding effectiveness, measured through production of the finest particle size fractions was significantly influenced by the operating pressure. The results show that higher values of operating pressure (4.0 and 4.5 N/mm 2 ) are not as efficient within this scope as the pressure 3.5 N/mm2. Dust emission is also correlated with the operating pressure value.

Mercury in tree rings close to emission sources in Austria.

Mercury in wood is an important pool of this heavy metal in forest ecosystems because of its relatively high proportion in the biomass compared to other pools. This paper describes the successful application of a modified methodology for stem disk sampling based on wood particles from stem disks from Donawitz (Styria, Austria; pig iron production), from Brixlegg (Tyrol; former copper and silver mining, copper ore processing and copper recycling), and from Gmunden (Upper Austria; cement production). The maximum mercury concentration in the stem disks from Donawitz (Hinterberg: 20.5ppb, St. Peter: 9.3ppb) was recorded in the early 1970s. Several maxima were obtained from the stem disks from Brixlegg: the first was in 1813 (149.9ppb), potentially even earlier, a second (37.6ppb) in the late nineteenth century until the late 1920s, and a third local maximum in the 1970s (9.1ppb), followed by a tendency to decline until the present. A stem disk from Gmunden in Upper Austria showed values of mercury concentrations indicating no increases compared to literature about background sites (≤ 3.2ppb). This method revealed trends in mercury concentrations in tree rings originating from several different mercury emission sources in Austria coinciding with information about industrial history (where available) together with a justifiable effort. We therefore recommend it for further investigations on mercury concentrations in tree rings and their changes over time.

Формирование экологического ущерба при складировании сульфидсодержащих отходов обогащения полезных ископаемых

The mining industry is one of the most challenging in ensuring environmental safety. During the last century, the Karabash Copper Smelting Plant was processing sulfide ores and depositing the tailings into storage facilities that now occupy an area of more than 50 hectares. To date, abandoned tailings are a significant source of natural water, air, and soil pollution in the Karabash city district. The article comprehensively examines the environmental impact of the Karabashmed copper smelter, one of the oldest metallurgical enterprises in Russia. The effects of seepage from the two Karabashmed tailings facilities on water resources were assessed. We revealed that even outside the area of the direct impact of processing waste, the pH of natural water decreases to values 4-5. Further downstream, the infiltration water from the tailings pond No. 4 reduces the pH of river water to 3.0-3.5. The presented results of environmental engineering surveys are derived from sampling water and bottom sediments of the Ryzhiy Stream and the Sak-Elga River, sample preparation, and quantitative chemical analysis. The study revealed significant exceedances of the maximum permissible concentrations for a number of chemical elements in the impact zone of the copper ore processing tailings.

Properties of Bacterial Copper Slag Concrete

Copper ore processing generates a large amount of copper slag, which has properties that are similar to fine aggregate. Copper slag has a promising future in the construction industry as an alternative to fine aggregate. Up to 50% of fine aggregate substitutions have been successful. The performance of copper slag concrete could be improved by microbiologically induced calcium carbonate precipitation. The impact of micro-organisms on the mechanical properties and flexural behaviour of copper slag concrete was investigated in this study. Five concrete mixtures were created by replacing varying amounts of fine aggregate with copper slag, ranging from 0% to 100%. M30 grade concrete was used, and 1% to 2% of the bacterium Bacillus subtilis by weight of cement was added during the concrete casting procedure. Specimens of different shapes, such as cubes, cylinders, and prisms, were cast and examined at 7, 14, and 28 days. When treated with micro-organisms, the test results revealed that replacing 50% to 75% of the sand with copper slag produced concrete with superior mechanical properties and a greater density. With the optimal ratio of copper slag to micro-organisms, a suitable RCC beam was formed. Load–deflection patterns of bacterial copper slag concrete were used to investigate beam flexural behaviour, and the results were compared using ABAQUS modelling. Microbiologically induced calcium carbonate precipitation can alter regular copper slag concrete, resulting in enhanced concrete performance.

Assessment of Environmental Health Risks Associated with Chemical Content of Drinking Water for Workers in the Copper and Gold Mineral Ore Processing Industry

Drinking water is a necessity for all living organisms and should be of good quality and free from hazardous contaminants. Chemical agents such as nitrate, nitrite, selenium, chromium, cadmium, manganese, cyanide, and fluoride can contaminate drinking water. Therefore, this study aims to analyze the health risks associated with these chemical agents and their potentially harmful effects on workers. The Environmental Health Risk Analysis (EHRA) method was used to evaluate the chemical agents present in the Concentrating Division area of PT Freeport Indonesia (PTFI). It was discovered that the average concentration values of all chemical agents were below the Environmental Health Quality Standards (EHQS) established in the Minister of Health Regulation Number 2 of 2023. The risk quotient (RQ) results, obtained through the division of intake and reference dose (RfD), were less than 1 (RQ<1), indicating that chemicals constituting the drinking water found in the Concentrating Division area did not pose health risks to workers. Risk management and communication efforts in the area are unnecessary because the detected chemical agents are considered safe. However, daily supervision of potentially hazardous chemical agents is still necessary.

The Escaramayu Complex: A Prehispanic Metallurgical Establishment in the South Andean Altiplano (Escara, Potosi, Bolivia), Ninth to Fifteenth Centuries AD

AbstractArchaeological research carried out in the altiplano locale of Escaramayu (in the community of Escara, Potosí, Bolivia), revealed a prehispanic metallurgical establishment (ninth to fifteenth centuries AD) for the extractive processing of copper ores and, to a lesser extent, lead-silver ore exploited at the nearby Pulacayo mine. The number and variety of metallurgical equipment identified in this establishment for smelting metallic ore and for refining the metal indicate a deep level of technological experience and experimentation among the resident Escaramayu metalworkers during the Middle Horizon (MH) and Late Intermediate periods (LIP). In Escaramayu we find the first known antecedents of Andean wind furnaces (wayras) and a model of a prehispanic reverberatory furnace that was widely used in the southern Andean altiplano during the colonial period.

Impact of the use of seawater on acid mine drainage from mining wastes

The copper mining industry is vital in the transition to fossil-free power for achieving sustainability worldwide, which is mainly based on the exploitation of copper sulfide ores. However, the mineral processing produces a large volume of mine tailings, and their quantity is almost equal to the ores treated. Acid mine drainage (AMD) is a challenging environmental problem caused by tailing disposal when it is not well managed. In addition, several copper mining companies employ seawater in their process because they operate in arid or semi-arid regions, including northern Chile, southern Peru, and Australia. For copper sulfide mineral processing, the use of seawater is not a limitation in the flotation process, and positive and negative effects appear compared to using fresh water. However, there are no records in the literature on the impact of seawater on the generation of AMD, considering that it is a solution with a high concentration of different ions. This study aims to evaluate the chemical stability of synthetic tailings with and without seawater by kinetic tests using seven humidity cells. The synthetic tailings are mixtures of pyrite, chalcopyrite, arsenopyrite, and quartz. The main results show that the AMD generation kinetics after 25 weeks of testing humidity cells leached with distilled water (acid-generating cells) behaved differently than the humidity cells leached with seawater (non-acid-generating cells). After 25 weeks of testing, the acid-generating humidity cells had a pH value below 2.26, while the non-acid-generating humidity cells had a pH value above 7. It was also shown that fine-particle-size granulometry generates AMD faster than coarse-particle-size granulometry. Finally, the sulfide minerals’ ion dissolution occurred when the humidity cells were leached with distilled water and not when leached with seawater. The results show that using non-desalinized seawater in copper ore processing can help prevent AMD due to the buffering effect of seawater and the protection coat formed by oxyhydroxide and/or bivalent cations.

Reconstruction of smelting conditions during 16th‐ to 18th‐century copper ore processing in the Kielce region (Old Polish Industrial District) based on slags from Miedziana Góra, Poland

AbstractThis study presents the first reconstruction of the smelting conditions in 16th‐ to 18th‐century smelters from Miedziana Góra (Holy Cross Mountains, Poland). Based on geochemical (inductively coupled plasma mass spectrometry/emission spectrometry, X‐ray fluorescence) and mineralogical analysis (X‐ray diffractometry, scanning electron microscopy, electron probe micro‐analysis) of historical slags, their chemical/phase composition and the basic smelting parameters (temperature, melt viscosity, and oxygen fugacity) were determined. Due to the differences in chemical and phase composition, slags from different smelting stages have been distinguished: hypocrystalline slags (MG6) from speiss/matte production and glassy (MG1–MG5) from matte conversion. In glassy slags, pyroxenes, quartz/cristobalite grains, and aggregates composed of metallic Cu and PbO are dispersed in the glass. Hypocrystalline slags are composed of wollastonites, anorthites, and metallic Cu. The temperature range at which the slags were formed was from ~1100°C (solidus temperature) to 1150–1200°C (liquidus temperature). The silicate melt's viscosity was from log η = 1.19 to 4.42 Pa s (at 1100–1200°C). The higher viscosity of MG1–MG5 slags indicates that, unlike MG6 slags, they were not formed during gravity separation. Information about the phase composition made it possible to determine the oxygen fugacity in the range of log fO2 = −4 to −12 atm. High oxygen fugacity indicates the oxidizing nature of the smelting process.

Flotation processing of copper-containing technogenic raw materials using a composite flotation reagent

The article presents the results of laboratory research on the possibility of flotation processing of copper-containing technogenic raw materials. Studies were performed using a sample of copper-containing tailings obtained after the processing of copper ore from the Kazakhstan deposit and a composite flotation reagent. The application of a combination of various collectors allows for raising technological indicators of flotation. The purpose of the research is the increase extraction of copper at flotation of copper-containing technogenic raw materials with the application of a composite reagent. The studied sample of tailings contains 0.23% of copper. A mixture of sodium butyl xanthate and thionocarbamate in the ratio of 1:1 was used as a composite flotation reagent. Parameters of flotation of copper-containing tailings were worked out: degree of regrinding, charges of sodium butyl xanthate, blowing agent T-92, and a composite reagent. Composite flotation reagent was fed into the flotation process of copper-containing tailings in the form of emulsion produced in a T 18 digital ULTRA-TURRAX dispersant. The optimal emulsification time of the composite flotation reagent was 1 min. Without emulsification in the composite reagent the percentage of particles smaller than 1.192 µm is 55.047%. After emulsification of the composite reagent for 1 minute, the percentage of particles smaller than 1.192 μm is 91.134%. In optimum basic mode the rough copper concentrate with a copper content of 4.2% was obtained with the extraction of 61.56%. With the use of a composite reagent, a blister copper concentrate with a copper content of 4.5% and a recovery of 66.54% was obtained. Extraction of copper increases by 4,98%.

Prevention of the Combined Cytotoxic Effect of Selenium and Copper Oxide Nanoparticles in the Animal Experiment

Background: Copper ore processing plants are the emission sources of aerosols having a complex chemical composition. The aerosol components polluting both the workplace air and the ambient air of the adjacent populated areas include selenium, copper, and nanoparticles of these metal oxides. Objective: To evaluate the combined cytotoxic effect of selenium and copper oxide nanoparticles following the administration of a bioprophylactic complex. Materials and methods: The exposure to cytotoxic chemicals was modeled on outbred female rats by a single intratracheal injection of a suspension of selenium and copper oxide nanoparticles at a concentration of 0.25 g/L, obtained by laser ablation. Cytological and biochemical parameters of the bronchoalveolar lavage fluid (BALF) were measured 24 hours after the exposure. A specially developed bioprophylactic complex was administered to a part of the experimental animals with feed and drink during a month prior to the injection. Results: A single intratracheal instillation of the suspension of SeO and CuO nanoparticles altered BALF cytological and biochemical parameters, thus indicating their pronounced cytotoxic effect. In the group of the exposed rats administered a preliminary course of biological prophylaxis, we observed a decrease in the absolute number of neutrophils and the neutrophil to alveolar macrophage ratio, which is an indirect indicator of the cytotoxic effect, and the activity of aspartate aminotransferase in the bronchoalveolar lavage fluid. Conclusion: The science-based and experimentally tested complex of bioprotectors can attenuate a combined cytotoxic health effect of the exposure to selenium and copper oxide nanoparticles.

Protective role of glutathione in oxidative stress caused by cadmium and copper

IntroductionCadmium is defined as one of the leading toxic industrial pollutants (Valko i sar., 2005). Although some products containing cadmium can be recycled, much of the pollution with this metal is the result of inadequate disposal and uncontrolled incineration of cadmium-containing waste (Jarup, 2003). Copper particles are released into the atmosphere from copper smelters and ore processing facilities, as well as from anthropogenic sources (use of pesticides, herbicides and fungicides). Oxidative stress occurs due to increased production of reactive oxygen species (Parkinson’s and Alzheimer’s disease) or reduced ability of cells to neutralize it through their internal antioxidants (eg mutation of the superoxide dismutase gene in amyotrophic lateral sclerosis).ObjectivesThe aim of this research was to examine the protective role of supplement, GSH, S-donor ligand, and in conditions of acute and chronic intoxication with sublethal doses of cadmium-II-chloride and copper II sulfate.MethodsAfter medial laparotomy albino rates Wistar soy, a 10% homogenate of brain tissue was made in an appropriate medium and an analysis of acid and alkaline DNase activity was performed (Kocić i sar., 2004; Kocić i sar., 1998).ResultsThis experiment demonstrated the beneficial role of GSH supplement that exhibit antioxidant character in preventing and reducing the adverse effects of acute and chronic cadmium and copper intoxication.ConclusionsAntioxidants prevent the formation of oxidative stress in the cell by reducing and stopping DNA damage and degradation, and thus represent potential scavengers of free radicals.DisclosureNo significant relationships.

The Impact of Residual Dispersant on the Flocculation and Sedimentation of Synthetic Tailings in Seawater

Dispersants under certain conditions favor the flotation of molybdenite in seawater; however, it is not clear if the entrainment of residues to the thickening stage can compromise the quality of the clarified water. In this work, the impact of small concentrations of sodium hexametaphosphate (SHMP) on the flocculation and sedimentation of synthetic tailings containing kaolinite, muscovite, and quartz in seawater is evaluated. The flocculant polymer is a high-molecular-weight polyacrylamide, and the pH is alkaline. The results are auspicious for mineral processing. On the one hand, the impact of SHMP is not entirely negative and can be lessened by limiting entrainment, which is good for copper and molybdenum ore processing. On the other hand, if the small increase in turbidity generated by the SHMP is tolerated, it is possible to expect improved settling speeds. Without SHMP, large but light agglomerates are formed. With SHMP, smaller but denser aggregates are formed, settling faster, and minute aggregates increase turbidity. The underlying mechanism derives from the competition between SHMP and polymer chains for the cations in solution; the result is a greater repulsion between the chains, which leads to greater repulsion and thus dispersion of smaller flocculant coils. The study shows that SHMP in concentrations of 1 to 3 kg/t is perfectly acceptable. The results represent an advance in the understanding of SHMP interactions with polymers and minerals in water clarification, which should be of interest to the industry whose sustainability in some regions depends on closing the water cycle.

The fate of molybdenum in the residues of a Chilean copper ore processing plant

Mining residues have become an important subject for secondary mining and re-processing. They are an inevitable consequence of mining activity with the amount of residues steadily increasing. These residues are heterogeneous bodies, affected by different processes during and after deposition, which might even produce an enrichment of certain valuable elements within parts of the residues. Since geochemistry and mineralogy of the ore can differ heavily due to processing, deposition and weathering within the heaps, the formerly applied processes might be less suitable for re-processing, therefore, these processes should be studied carefully for an effective re-processing. This study examines the fate of molybdenum in the processing of copper ore in a Chilean processing plant. Molybdenum shares the path of Cu from grinding and flotation into the sulfide concentrate. During smelting and converting, the sulfide concentrate is separated gravitationally from the slag. Through the subsequent slag cleaning process, the slag is crushed and submitted to flotation again, but this time the Mo in its oxidized state reports to the tailings and, hence, is deposited on the tailings heap. Drill cores of the heap have been analyzed by X-ray fluorescence spectroscopy revealing a layer of significant Mo enrichment with up to 0.3 wt.-% Mo. From this layer, the minerals within the slag particles were analyzed by more than one thousand electron microprobe analyses. The results show that Molybdenum is enriched mostly in the glassy matrix (median of 0.18 wt.-%), while the spinel phase, which generally incorporates most of the Mo according to literature, contains a smaller fraction of the Mo (median of 0.09 wt.-% Mo). Additionally, within the slag, the glass amount is up to a factor five higher than the magnetite, therefore, the glass poses as the main reservoir for Mo in the heap. Considering the general process, the missing step of Mo-extraction from the sulfide concentrate combined with the slag cleaning process for Cu extraction is responsible for the enrichment of Mo in the slag rich part of the investigated heap.