Copper Sulfide Minerals Research Articles

Further Results on the Effects of the Grinding Environment on the Flotation of Copper Sulphides

Grinding conditions affect the flotation of copper sulphide minerals as changes in the properties of the grinding media and their interactions with the sulphide minerals, and between sulphide minerals themselves, affect the chemical environment in the flotation pulp. Galvanic interactions between steel grinding media and sulphide minerals, and between sulphide minerals, can lower the pulp potential, decrease the dissolved oxygen concentration in the mineral slurry, and lead to the dissolution of iron and copper from the media and the minerals. As a result, the formation of hydrophilic iron hydroxides and their adsorption on the copper sulphide minerals can be deleterious to copper flotation while pyrite (when present) can be activated to flotation by dissolved copper lowering the grade of the copper concentrate. Electrochemically less active grinding media (e.g., chrome alloy balls rather than mild steel media) can have beneficial effects on flotation performance due to the lower oxidation of the grinding media and consequently the lower production of oxidised iron species in the pulp. Copper activation of pyrite can be decreased by chemical additions to the pulp. In this paper, relevant experimental data published in the last 15 years are discussed.

Spectroelectrochemistry study on the surface modification of chalcopyrite by Cu2+ and its depressive response to flotation collector adsorption by negative potential

In the flotation beneficiation of copper and molybdenum co-occurrence ores, the efficient depression of chalcopyrite is crucial for successful copper-molybdenum separation. However, the consumption of conventional depressant NaHS is huge. There is greater susceptibility of chalcocite and other secondary copper sulfide minerals to electrochemical reaction in comparison to chalcopyrite. Given the irreversible desorption behavior of collector molecules on chalcocite upon negative potential application, electrochemically regulated flotation can be effectively utilized to diminish the utilization of conventional depressants. In this work, electrochemistry and shell-separated nanoparticle-enhanced Raman spectroscopy (SHINERS) were used to explore the transformation of chalcopyrite surface to chalcocite-like species under the combined action of Cu2+ and negative potential. The results show that the similarity of cyclic voltammetry (CV) between the modified chalcopyrite and chalcocite, increases with the pretreatment potential becoming increasingly negative. Electrochemical impedance spectroscopy (EIS) also reflects their similar adsorption and desorption behavior in response to ammonium dibutyl dithiophosphate (ADD), a typical flotation collector molecule. In addition, the spectroelectrochemical directly reflects the irreversible desorption of ADD molecules from the modified chalcopyrite surface at − 0.7 V. The research results lay a theoretical foundation for the efficient Cu-Mo separative flotation by depressing chalcopyrite under the combination of Cu2+ and negative potential.

Quantifying pyrrhotite superstructures in copper-gold ore flotation through synchrotron X-ray diffraction analysis

Pyrrhotite, a significant sulfide mineral in base metal sulfide deposits, exists in various superstructures including magnetic (4C) and non-magnetic (5C and 6C) types. Identifying and quantifying pyrrhotite superstructures in an ore sample has been a challenge, hindering efforts to improve pyrrhotite rejection in copper–gold flotation. This study employed synchrotron X-ray powder diffraction (S-XRPD) analysis to quantify pyrrhotite superstructures in the concentrates obtained from flotation of a copper–gold ore after grinding with forged steel and 30% chromium grinding media. S-XRPD demonstrated a superior capability in detecting characteristic peaks of 4C, 5C and 6C pyrrhotite superstructures compared to conventional XRPD. Utilizing the Rietveld refinement method, the identified pyrrhotite superstructures were quantified. These findings were successfully validated through independent X-ray fluorescence analysis on elemental compositions. The quantification work demonstrated that 30% chromium grinding media enhanced the floatability of all pyrrhotite superstructures over forged steel grinding media and each pyrrhotite superstructure in the copper–gold ore resembled a copper sulfide mineral rather than pyrite in response to grinding media during flotation. This research highlights the potential of S-XRPD as an effective technique for identifying and quantifying pyrrhotite superstructures in ore samples and determining their flotation behaviors.

Copper sulfide mineral performs non-enzymatic anaerobic ammonium oxidation through a hydrazine intermediate.

Anaerobic ammonium oxidation (anammox)-the biological process that activates ammonium with nitrite-is responsible for a significant fraction of N2 production in marine environments. Despite decades of biochemical research, however, no synthetic models capable of anammox have been identified. Here we report that a copper sulfide mineral replicates the entire biological anammox pathway catalysed by three metalloenzymes. We identified a copper-nitrosonium {CuNO}10 complex, formed by nitrite reduction, as the oxidant for ammonium oxidation that leads to heterolytic N-N bond formation from nitrite and ammonium. Similar to the biological process, N2 production was mediated by the highly reactive intermediate hydrazine, one of the most potent reductants in nature. We also found another pathway involving N-N bond heterocoupling for the formation of hybrid N2O, a potent greenhouse gas with a unique isotope composition. Our study represents a rare example of non-enzymatic anammox reaction that interconnects six redox states in the abiotic nitrogen cycle.

Hollow drop bubbles: A preliminary study of simplified prototype for improving copper(II) extraction with ACORGA® M5640 using coated bubble swarm

There are two well-defined processes for the types of copper ores. One for the processing of copper sulfides and another for the processing of the copper oxides. There are similarities between the two, particularly in the preparation stage of the run of mine (ROM) such as the crushing. However, significant differences exist in how to concentrate the elements of interest. Flotation is the most used concentration process to separate copper sulfide minerals from other minerals using air bubbles. For oxides, after the dissolution of copper, the solvent extraction (SX) process is the preferred path using two immiscible liquids to separate the copper.A line of investigation for solvent extraction is the use of a bubble coated with solvent to extract the metal of interest from the aqueous solution, some devices have been built and tested for this purpose using different principles to generate a coated bubble swarm. However, those equipments have been tested on laboratory and have not been scaled up to an industry level.The Hollow Drop (HD) concept was born from the idea of building a device to generate coated bubbles in a continuous swarm that could be scalable to an industry level. In this paper two columns were built and operated: a proof-of-concept column and a scale-up attempt for the extraction of Cu(II) fom an aqueous solution of 2.5 g L−1 using ACORGA® M5640 (25% v/v) in the Kerosene.The results show that we could generate a bubble swarm and conduct the solvent extraction process at a 97% recovery using our proposed coated bubble generator. However, in our scaled prototype test only a 70% recovery was achieved, which shows that our column is working but the scaling-up needs more investigation regarding the dimensions and flows of the process.

Халлимонд түтігіндегі мыс сульфидті минералдардың флотациясы

Under laboratory conditions, studies were carried out to determine the hydrophobicity of the surface of copper sulfide minerals bornite and chalcopyrite by differential thermal analysis and the infrared (IR) spectra of samples of these minerals were studied before and after the experiments. From the nature of the absorption of copper sulfide minerals by IR radiation, it is possible to determine the best indicators of the adsorption of reagents on the surface of minerals. When treating the chalcopyrite surface with anabazinium-O, O-dimethylthiophosphate and N-phenylthiosemicarbazide reagents N-morpholinylacetic acid has been found to weaken hydrogen bonds and evaporate adsorbed moisture. This indicates an increase in the hydrophobicity of the chalcopyrite surface compared to bornite. Studies of the non-soil flotation of the monomineral fraction of sulfide minerals were carried out in the Hallimond tube. During flotation of chalcopyrite treated with a solution of 1% N-phenylthiosemicarbazide of N-morpholinyl acetic acid, its extraction was 94.54%. The achieved indicators are confirmed by the results of differential thermal analysis and IR spectroscopy

Resource potential of the Proterozoic–Paleozoic Carrara depocentre, South Nicholson region, Australia: Insights from stratigraphic drilling

A comprehensive geochemical program was carried out on rock samples collected in the NDI Carrara 1 drill hole, the first stratigraphic test of the newly discovered Carrara Sub-basin located in the South Nicholson region of northern Australia. The drill hole recovered continuous core from 284 m to total depth at 1750 m and intersected approximately 1120 m of Proterozoic sedimentary rocks, unconformably overlain by 630 m of Cambrian Georgina Basin carbonate-rich rocks. Total organic carbon (TOC) contents from Rock-Eval pyrolysis highlight the potential for several thick black shales to be a source of petroleum for conventional and unconventional plays. Cambrian rocks contain an organic-rich section with TOC contents of up to 4.7 wt.% and excellent oil-generating potential. The Proterozoic section is overmature for oil generation but mature for gas generation, with potential for generating gas in carbonaceous mudstones showing TOC contents up to 5.5 wt.% between 680 and 725 m depth. A sustained release of methane (up to 2%) recorded during drilling from 1150 to 1500 m suggests potential for an unconventional gas system in the Proterozoic rocks from 950 to 1415 m depth, which exhibit favourable organic richness and thermal maturity. The Proterozoic rocks, which are comparable in age to the sediment-hosted deposits of the Century Mine, contain local occurrences of lead, zinc and copper sulfide minerals providing hints of mineralisation. The combined geochemical results offer the promise of a potential new resource province in northern Australia.

Sodium metabisulfite as a copper depressant in the selective flotation of copper-molybdenum concentrate using seawater

The main challenge for the selective flotation of copper and molybdenum (Cu-Mo) sulfide minerals in seawater is the formation of colloidal precipitates in strongly alkaline conditions. These precipitates hinder the selective separation of copper from molybdenum minerals in seawater by lowering the floatability of Cu-Mo sulfide minerals. The present study aimed to examine the direct utilization of seawater in the selective flotation of Cu-Mo sulfides. Additionally, the effectiveness of sodium metabisulfite (Na2S2O5) as a copper depressant for selective flotation of Cu-Mo sulfides in seawater was studied under weakly acidic, neutral, and moderately alkaline conditions. A complex Cu-Mo concentrate that largely consisted of chalcopyrite and molybdenite, as well as a tiny amount of pyrite and quartz, was used in the flotation tests. The flotation results revealed that treatment with 3.6 kg/t Na2S2O5 in seawater at pH 5.5 significantly lowered the copper recovery from 97% to 11% and caused a modest reduction in the molybdenum recovery from 98% to 94% with a Cu-Mo separation efficiency of 83%. These flotation results demonstrate that Na2S2O5 treatment in seawater selectively depresses the floatability of copper minerals. Consequently, molybdenum can be separated from copper minerals under a weakly acidic condition in seawater. In addition, this study discusses the effects of various pH conditions and dosages of Na2S2O5. The surface properties of Cu-Mo minerals were studied using X-ray photoelectron and infrared spectroscopies, and a mechanism to explain the selective flotation of Cu-Mo using Na2S2O5 treatment in seawater is proposed.

Mineralogy and Conditions of Formation Genesis of Aggregates of Natural and Sulfide Minerals of the Poldnevskoe Demantoid Deposit (Middle Urals)

Polymineral aggregates of rounded shapes (“nodules”) composed of native and sulfide minerals of Cu, Ni, Fe, Ag, and other elements from vein magnetite–calcite–chrysotile rocks with jewelry demantoid in the Korkodinskoe hypermafic massif are described. A common feature of the six identified types of native sulfide nodules, composed of native copper, heazlewoodite, pentlandite, cuprite, and other native sulfide minerals, is their spheroidal shape, which makes them similar to individual grains of other gangue minerals (calcite, magnetite, etc.). In heazlewoodite–pentlandite nodules, specific symplectites of mercuric silver and nickel copper in heazlewoodite, as well as awaruite in Co–pentlandite, were found. The matching set of ore minerals in the host serpentinite vein mass (native copper, mercuric silver, heazlewoodite, pentlandite, awaruite) and nodules from the vein material indicates their genetic connection and the conjugation of demantoid mineralization with the evolving processes of serpentinization. It was established that the nodules formed at temperatures below 380°C under reducing conditions at very low sulfur fugacity values (10–17–10–27 bar) and oxygen (10–30 bar at 200°C to 10–21 bar at 350°C). For heazlewoodite–pentlandite nodules, such conditions persisted throughout the entire time of their formation, while, for other nodules, the reducing conditions of early parageneses were replaced by oxidative conditions in late parageneses, which is recorded by the replacement of native copper with cuprite. It is assumed that the features of the morphology and structure of native sulfide nodules and the presence of symplectite intergrowths of ore minerals in them are associated with specific conditions created during the decompression of the crust-mantle mixture rising to the surface in the fault zone. The source of the metals was a deep, high-temperature fluid interacting with mafic and ultramafic rocks under reducing conditions at a low water-to-rock ratio.

Effect of oxidation treatment on the selective separation of molybdenite from chalcocite using flotation

Molybdenite is associated with primary and secondary copper sulfide minerals. Few studies have focused on the selective flotation of molybdenite to separate it from secondary copper sulfide minerals, such as chalcocite. This study evaluated the use of oxidation treatment to separate molybdenite from chalcocite. The effects of oxidation treatment with hydrogen peroxide (H2O2) on the flotation behaviors of molybdenite and chalcocite in the presence of collectors (i.e., potassium amyl xanthate and diesel oil) were evaluated, and the impacts of H2O2 concentration, oxidation treatment duration, and pH level were assessed. Chalcocite flotation tests showed that the H2O2 treatment significantly reduced the recovery of chalcocite due to the formation of copper hydroxide and sulfate species on the chalcocite surface, which altered its surface hydrophobicity. On the other hand, the low surface oxidation of molybdenite led to high flotation recovery after the oxidation treatment. Oxidation treatment with a 10 mM H2O2 solution at a pH of 9 for 20 min resulted in a separation efficiency of 87%, with 98% molybdenite recovery and 11% chalcocite recovery. The results show that H2O2 oxidation treatment enables the selective flotation of molybdenite to separate it from chalcocite.

The use of seawater in copper hydrometallurgical processing in Chile: A review

Seawater has become a viable alternative for different uses in copper hydrometallurgy. In this paper we review the main physical and chemical characteristics of seawater and how these influence copper production. Reliable data on the use of continental water are reported, and the current use and consumption of seawater in the Chilean mining industry is analysed, indicating the main areas of use and the main problems encountered. Additionally, the influence of the elements in seawaterthat have the most influence on the extractive metallurgy of copper are considered. The Chilean copper mining industry currently consumes approximately 4.1 m3/s of seawater, which corresponds to 25% of the total water used. The use of seawater for the leaching of copper sulphide minerals, such as chalcopyrite, is beneficial because it provides 20 g/L of chloride, thereby improving copper dissolution kinetics.

Fluid Flow, Alteration, and Timing of Cu-Ag Mineralization at the White Pine Sediment-Hosted Copper Deposit, Michigan, USA

Abstract White Pine, located in Michigan’s Upper Peninsula, is an archetypal sediment-hosted stratiform copper deposit. The Midcontinent rift system is one of only seven basins globally that host a giant sediment-hosted stratiform copper deposit. Despite many similarities with other deposits of this type, White Pine displays some important differences, including the late Mesoproterozoic age, a thick basalt sequence, an apparent lack of evaporites, and a lacustrine depositional setting. This study analyzes paleofluid flow related to the formation of White Pine and places a particular emphasis on structural and diagenetic fluid pathways. Most of the ore is located in a 30-m-wide zone spanning the Copper Harbor Formation red beds and the overlying Nonesuch Formation shales. Sedimentation of these units was accompanied by subtle synsedimentary faulting. Premineralization phases include calcite concretions and nodules, illite and hematite grain coatings, isopachous chlorite rims, emplacement of liquid petroleum (now pyrobitumen), and bleaching. Mineralization introduced native copper into the footwall sandstones and a zoned suite of native copper and sulfur-poor copper sulfide minerals across a migrating redox front in the overlying shales where copper minerals nucleated on authigenic and detrital chlorite grains. Postmineralization phases include quartz cement, calcite cement, and calcite veins that partially overlapped inversion of synsedimentary faults. Contrary to previous studies, we identified evidence for only one phase of mineralization. An Re-Os chalcocite age of 1067 ± 11 Ma places mineralization 11 to 17 m.y. after host-rock deposition. Sulfide δ34S values of –14.0 to 29.9‰ suggest an important contribution from sour gas and thermochemical sulfate reduction of seawater. Carbon (δ13C) and oxygen (δ18O) isotope compositions of five calcite generations range from –15.1 to –1.3‰ and 10.4 to 41.3‰, respectively, and record early meteoric pore water displaced by later seawater. White Pine is both a sediment-hosted stratiform copper deposit and a paleo-oil field. Synsedimentary faults controlled the sedimentological character of the upper Copper Harbor Formation, and together these imparted a strong control on fluid flow and later diagenetic processes. Early oxidized meteoric fluids were displaced by liquid petroleum and sour gas, which were in turn succeeded by metal-rich but sulfate-poor oxidized seawater. Burial compaction during deposition of the overlying Freda Formation drove fluids through White Pine due to its situation on a paleotopographic high near the basin margin. Mineralization occurred at ~125°C at depths of ~2.0 km and spanned incipient basin inversion related to the distal effects of Grenvillian orogenesis. The hightenor copper mineral assemblage is the product of an abundant supply of metal from basaltic volcanic detritus in the Copper Harbor Formation and low seawater sulfate concentrations in late Mesoproterozoic oceans. This demonstrates that viable sediment-hosted stratiform copper systems can form when a readily leachable metal source rock is present, even if hypersaline and sulfate-rich brines are not.

From understanding the rate limitations of bioleaching mechanisms to improved bioleach process design

While bioleaching has become established technology for the leaching of refractory gold concentrates and in the heap leaching of copper sulfide minerals, many other applications, although demonstrated at the laboratory scale, have not found significant uptake in industrial biomining. The reasons for this are manifold, but generally relate back to engineering constraints in operating processes at large scale while remaining economically viable.The paper unpacks acidophile sulfide bioleaching mechanisms within bioreactors into various sub-processes and analyses them in terms of their rate limitations, such as gas-liquid mass transfer of oxygen and CO2, diffusion constraints between and within mineral particles, competing side reactions etc. It becomes clear that microbial metabolic reactions are generally not what limits the kinetics of bioleaching reactions overall but rather the reaction environment. Improved process design to enhance the economic performance of bioleaching therefore needs to target the slowest sub-process in the bioleaching mechanism, which is rarely the biological one.Conventional tank and heap bioleaching processes are discussed in this context and routes taken towards their improvement discussed. Further, various promising novel concepts in biomining, such as leaching with biogenic lixiviants, phytomining and tailings leaching are evaluated within this framework, in each case identifying the potentially limiting sub-processes. It becomes clear that the relative ‘slowness’ of these sub-processes prohibits exploitation through designed active industrial processes; they can, however, still be facilitated through suitably designed ‘passive’ processes in which the time taken for slow processes is less of an economic constraint. While this is an obvious approach in bioremediation, it can also be employed for the economic recovery of value from otherwise sub-economic mineral deposits and waste materials through heap bioleaching. This way it can also play a role in the drive towards a circular economy.

Comparison of sphalerite, djurleite, and chalcopyrite leaching by chemically and biologically generated ferric sulfate solutions

Ferric leaching, including the oxidation of sulfide raw materials of nonferrous metals in a ferric sulfate solution, is a well-known hydrometallurgical process that is widely applied in practice. Recent studies have indicated differences in the leaching kinetics of sphalerite concentrates when using solutions of ferric sulfate obtained by dissolving a commercial reagent or after bio-oxidation of iron-containing substrates by acidophilic chemolithotrophic microorganisms. In this research, the leaching of powder samples of natural zinc and copper sulfide minerals (sphalerite, djurleite, and chalcopyrite) was compared using two different solutions. The first one was an aqueous solution of a chemically pure ferric sulfate reagent, and the second solution contained ferric sulfate obtained via biooxidation of the chemically pure reagent of ferrous sulfate by an acidophilic bacterium Leptospirillum ferriphilum. The leaching solutions contained 10.1 g/L of ferric iron, pH 1.3. The experiments were carried out in batch mode in a mechanically stirred reactor. When using a solution of the chemical reagent of ferric sulfate, the level of dissolution of sulfide minerals was higher than in the case of the biological reagent: by 21.3% after 5 h (80 °C; 1% pulp density) for sphalerite, by 11.8% after 3 h (80 °C; 1% pulp density) for djurleite, and by 9.1% after 5 h (80 °C; 0.5% pulp density) for chalcopyrite. A comparison of the results of experiments with the biological reagent throughout from which microbial cells were preliminarily removed and the chemical reagent to which microbial cells were added confirmed the pivotal role of microbial cell lysis products in decreased efficiency of leaching with the biological reagent. Metabolomics analysis revealed several potential metabolites of L. ferriphilum involved in the observed negative effect on the leaching effectiveness, including nucleosides, alkaloids, and benzaldehydes. By contrast, the efficiency of zinc leaching from sphalerite was improved in the presence of metabolism products of L. ferriphilum in the first hours of the process.

Overexpression of quorum sensing genes in Acidithiobacillus ferrooxidans enhances cell attachment and covellite bioleaching

Cell adhesion is generally a prerequisite to the microbial bioleaching of sulfide minerals, and surface biofilm formation is modulated via quorum sensing (QS) communication. We explored the impact of the overexpression of endogenous QS machinery on the covellite bioleaching capabilities of Acidithiobacillus ferrooxidans, a representative acidophilic chemolithoautotrophic bacterium. Cells were engineered to overexpress the endogenous qs-I operon or just the afeI gene under control of the tac promoter. Both strains exhibited increased transcriptional gene expression of afeI and improved cell adhesion to covellite, including increased production of extracellular polymeric substances and increased biofilm formation. Under low iron conditions, the improved bioleaching of covellite was more evident when afeI was overexpressed alone as compared to the native operon. These observations demonstrate the potential for the genetic modulation of QS as a mechanism for increasing the bioleaching efficiency of covellite, and potentially other copper sulfide minerals.

Copper leaching from the chalcopyrite-bearing MoS2 concentrate by mixed chlorides solution

In this study, the dissolution of copper sulfide minerals by the ferric (FeCl3) and ferrous (FeCl2) chloride leaching for upgrading the content of molybdenum disulfide (MoS2) in a molybdenite concentrate was investigated. The effect of various parameters was studied on the copper dissolution behaviour from the concentrate. In this matter, the copper dissolution was reached 94.84 % under the optimized leaching conditions. The kinetics of copper dissolution from the concentrate was established using a shrinking core model (SCM), and the process was controlled by diffusion, with a corresponding activation energy of 18.63 kJ mol-1 at the temperature range of 343?373 K. The amount of cop-per in the leachate was tested by the inductively coupled plasma-optical emission spectrometer (ICP-OES) and the solid phase was studied by X-ray diffraction (XRD), and scanning electron microscope (SEM). Results of the experiments show that the content of MoS2 in the solid residue was increased up to 88.59 % after the leaching.

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.

Research progress in intensified bioleaching of chalcopyrite: A review

Chalcopyrite (CuFeS2) as one of the most abundant copper sulfide minerals, is refractory to conventional hydrometallurgical and pyrometallurgical processes. Bioleaching is a practice of extracting valuable metals by using acidophilic bacteria to catalyse the dissolution of sulfide/iron-containing ores. It has been widely adopted in copper ores processing due to environmental and economic performance over the conventional methods, especially its use in low-grade sulfide minerals. To date, low copper extraction is a common problem during chalcopyrite bioleaching, which limits its industrial application. Hence, it is of particular importance to find methods to enhance the leaching rate. Chalcopyrite dissolution is a complex process with the participation of microorganisms, minerals and gas and liquid phases. All these physicochemical, microbiological, mineralogical and processing parameters have influences on the rate and efficiency at which bioleaching proceeds. High copper yield can be achieved by optimizing leaching conditions in an optimum range. A number of researches has been conducted to explore the influence of leaching parameters on bioleaching rate. This review intends to briefly describe the effect of some parameters on the bioleaching of chalcopyrite. And it lays the emphasis on the presentation of methods to promote the efficiency of bioleaching and the strengthening mechanisms.

Designing a copper mineral processing plant in virtual reality: A new tool for mining engineering education

In 2021, Queen’s University partnered with BBA Engineering Consultants to build a full-scale, virtual reality copper sulphide mineral processing plant. This project, financially support by e-Campus Ontario, aims to prepare Ontario post-secondary institutions to increase their training capacity in mineral processing to meet projected labour demands. The tool includes an environment where engineering students can work in real-time to diagnose problems in a high-fidelity and safe manner using virtual reality to sharpen real-life problem solving and design skills, so students are workplace-ready for employment in the mining industry. This paper examines the design process beginning with conceptual design, through detailed design and pilot testing. Various aspects of the project are discussed, including the agile project management approach, the importance of considering pedagogical objectives early in the project, the value of partnering with industry, and plans for further development of the tool.

Flotation Separation of Covellite and Enargite via Oxidation Treatment

The flotation separation of enargite from copper sulfide minerals is difficult owing to the similar floatability and reagent adsorption characteristics of these minerals. In this study, the effect of oxidation treatment using NaClO flow with FeCl3 on the flotation separation of covellite and enargite was systematically investigated. Micro-flotation tests and contact angle measurements indicated that the addition of NaClO and FeCl3 increased the hydrophobicity difference between covellite and enargite. The bench-scale flotation test results show that the bulk copper concentrate could be separated into two products: a low-arsenic-containing (0.46%) and a high-arsenic-containing (5.18%) copper concentrate. X-ray photoelectron spectroscopy and scanning electron microscopy revealed that the oxidization treatment of NaClO caused the accumulation of oxides on the covellite surface, but not on the enargite surface. The varying precipitation of ferric hydroxide on the surfaces of covellite and enargite further exacerbated the difference in the hydrophilicity of these minerals. Thus, a possible method for separating enargite from covellite was obtained through oxidation treatment using NaClO and FeCl3.