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Since the order–disorder phase transition easily occurs during the growth of optoelectronic II–IV–V2 ternary compounds, cation–cation antisites were always considered as the major point defects, while anion-related defects did not attract sufficient attention. In this paper, based on first-principles simulations, the anion–cation antisites are revealed to be comparable to or even dominate over the cation–cation antisites in II–IV–V2 phosphides and arsenides. These antisite defects are predicted to have significant impacts on the optoelectronic properties because they can either act as nonradiative recombination centers or enhance the p-type carrier concentration. Furthermore, based on the calculated defect properties and band alignments, we propose that the alloy ZnGe(P,As)2 can be an efficient p-type solar cell absorber. Its maximal open circuit voltage is effectively enlarged by the low valence band edge; meanwhile, the dominating anion–cation antisites are electrically benign. These results highlight the necessity of considering the anion–cation antisites in the defect engineering of II–IV–V2 phosphides and arsenides. [ABSTRACT FROM AUTHOR]

Aluminum recycling is an important step to achieve high value-added utilization of fly ash to improve the leaching efficiency of Al. In this paper, Na2CO3 was used as the flux and HCl as the leaching solution to extract Al from CFA by using the roasting activation-acid leaching process to investigate the influencing factors of the leaching rate of Al to analyze the mineral composition of the roasting products explore the activation process of CFA roasting. The experimental results showed that compared with NaF, CaO, and NaOH, the highest Al leaching rate was achieved when Na2CO3 was used as a flux, at which time the leaching rate could reach up to 81.62%, and it was about 63% higher than that of extracting Al from the fly ash using direct roasting-acid leaching method. When the roasting time is 90 min, the roasting temperature is 850°C, the CFA/Na2CO3 is 1.5, the hydrochloric acid concentration is 4 mol/L, the acid leaching temperature is 90°C, the S/L is 1:4, and the maximum leaching rate of Al is 81.62%. According to the thermodynamic theory, Na2CO3 and mullite gradually reacted with each other above 800 K to form chalcopyrite, and Na2CO3 reacted with mullite and quartz in CFA to form chalcopyrite more easily. According to the reaction kinetic model, the acid leaching process of CFA is mainly controlled by diffusion, and a semi-empirical equation is proposed to describe the whole leaching process. [ABSTRACT FROM AUTHOR]

Chalcopyrite has been extensively utilized for tracing geological processes through its Cu, Fe and S isotopic compositions. However, the matrix-matched reference materials for micro-analysis are lacking. This study focused on assessing the feasibility of a natural chalcopyrite specimen (IGGCcp-1) as a matrix-matched reference material for in situ micro-analysis of Cu, Fe, and S isotopes. Electron probe microanalysis validated the uniform distribution of major elements within chalcopyrite grains, with no evidence of growth zoning. Random spot isotopic measurements using LA-MC-ICP-MS demonstrated remarkable consistency in δ65Cu, δ56Fe and δ34S. These results indicated that the IGGCcp-1 specimen exhibited its suitability as a reference material. Using SN-MC-ICP-MS technique, the δ65Cu value was accurately determined to be 0.43 ± 0.05‰ (2S, N = 30). Furthermore, the δ56FeIRMM-014 and δ57FeIRMM-014 values were recorded as -0.24 ± 0.04‰ (2S, N = 18) and -0.36 ± 0.09‰ (2S, N = 18), respectively. Additionally, the δ34SVCDT measurement, performed with EA-IRMS, yielded a value of -0.28 ± 0.60‰ (2S, N = 10). These precisely measured isotope ratios established the recommended reference values for the IGGCcp-1 sample in future applications of Cu, Fe, and S isotope micro-analysis. [ABSTRACT FROM AUTHOR]

A simple, rapid, economical, and non-enzymatic electrochemical sensor for sensitive determination of hydrogen peroxide (H2O2) was developed based on a physical combination of carbon black (CB) and pure chalcopyrite modified glassy carbon electrode (GCE). Field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) were used to evaluated the morphology of the modified electrode. The proposed sensor (CuFeS2-CB/GCE) was investigated electrochemically using cyclic voltammetry (CV), amperometric methods (AP), and electrochemical impedance spectroscopy (EIS). The CuFeS2-CB/GCE sensor exhibited excellent stability and sensitivity with a linear concentration range from 2.5 to 60 mM (R2 = 0.9903) using CV and 0.1 to 100 mM (R2 = 0.9999) using AP. The corresponding limits of detection (LOD) are 1.0 mM and 0.04 mM (S/N = 3) for CV and AP, respectively. Both linear range and sensitivity of the prepared sensor were enhanced through the combination of chalcopyrite and CB. The practicality of the proposed sensor was further tested by measuring H2O2 in real samples. Additionally, the prepared sensor showed good selectivity to H2O2, resisting interference from other potential interferent compounds (e.g., glucose, fructose, urea, catechol, and common metal ions), and the sensor possesses acceptable long-term stability. [ABSTRACT FROM AUTHOR]

Chalcopyrite ores are processed mostly by pyrometallurgical techniques due to the refractory nature of the mineral to the current hydrometallurgical techniques. In order to overcome such refractoriness, pretreatment steps such as sulfurization may be applied to produce different copper phases and therefore improve the metal dissolution in the leaching step. The current study investigated the reaction products of the reaction between chalcopyrite and elemental sulfur at different chalcopyrite/sulfur ratios (1/1 and 1/2), reaction time (60 min and 90 min), and temperature (350ºC, 400°C and 450ºC). The sulfurization experiments revealed that covellite, nukundamite, bornite, and pyrite-like compounds were produced according to the experimental conditions applied. Then, the sulfurization products were submitted to chemical leaching tests at temperatures ranging from 32ºC to 70ºC, whereas bioleaching tests were also carried out with Acidithiobacillus ferrooxidans, at 32ºC. In the chemical leaching experiments at 70ºC, only 14% copper was recovered from the original chalcopyrite sample while the maximum copper extraction was 78% from bornite produced at 450ºC (90 min and mass ratio of chalcopyrite/sulfur of 1/2). On the other hand, copper extraction achieved 96% from the same sulfurization product containing synthetic bornite within 20 days of bioleaching. Bioleaching of the original chalcopyrite sample implied in a copper recovery of only 25% in the same period. Summarizing, the current work showed that chalcopyrite sulfurization at 450ºC was able to transform chalcopyrite into a bornite-like phase, which was chemically leached and bioleached by At. ferrooxidans. [ABSTRACT FROM AUTHOR]

The concentrate grade in chalcopyrite flotation is often compromised by the associated inherently floatable gangue such as graphite. In this study, eco-friendly xanthan gum (XG) was introduced as a graphite depressant in the flotation of chalcopyrite. Single minerals flotation showed that XG strongly reduced the floatability of graphite at pH 7.5 with no significant effect on the flotation of chalcopyrite. Mixed minerals flotation showed that the addition of 20 mg/L XG increased copper grade and selectivity index by 16.83% and 14.23, respectively. This selective depressing behavior of XG was due to the strong affinity between XG and graphite as well as the weak interaction between XG and chalcopyrite, as suggested by electrokinetic and adsorption measurements. FTIR and XPS analyses indicated that the adsorption of XG on the graphite surface could be governed by physical adsorption mechanisms. Furthermore, since the contribution of hydrogen bonding interaction was insignificant, hydrophobic interaction was considered as the dominant driving force in the adsorption process. This investigation demonstrates the promising potential of XG for graphite depression and may contribute to the greening of chalcopyrite flotation process. [ABSTRACT FROM AUTHOR]

Cathodoluminescence and electron backscatter diffraction have been applied to exactly the same grain boundaries (GBs) in a Cu(In,Ga)S2 solar absorber in order to investigate the influence of microstructure on the radiative recombination behaviour at the GBs. Two different types of GB with different microstructure were analysed in detail: random high angle grain boundaries (RHAGBs) and Σ3 GBs. We found that the radiative recombination at all RHAGBs was inhibited to some extent, whereas at Σ3 GBs three different observations were made: unchanged, hindered, or promoted radiative recombination. These distinct behaviours may be linked to atomic-scale grain boundary structural differences. The majority of GBs also exhibited a small spectral shift of about ±10 meV relative to the local grain interior (GI) and a few of them showed spectral shifts of up to ±40 meV. Red and blue shifts were observed with roughly equal frequency. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Low-temperature bioleaching is relevant to the recovery of metals in alpine mines, but its development has been constrained by low bioleaching rates at high pulp concentrations. To this end, the bioleaching effect of the microbial community after the domestication of pulp concentration at 6 °C was studied. Domestication improved the bioleaching rate of copper. Environmental scanning electron microscopy (ESEM), X-ray diffraction (XRD), and electrochemical measurements revealed that the domestication process aggravated the corrosion of the chalcopyrite surface by accelerating its dissolution reaction. High-throughput sequencing technology indicated that Acidithiobacillus spp., Leptospirillum spp., and Acidiphilium spp. were the major lineages of the domesticated microbial community. The analysis of the microbial community revealed that domestication changed the microbial structure, enhancing the adaptability of the microbial community to pulp concentrations and acidic conditions. This study uncovered the mechanism by which domestication enhanced the bioleaching efficiency of the microbial community at low temperatures. [ABSTRACT FROM AUTHOR]

AgGaTe2 is an attractive material for the light‐absorbing layer in solar cells and has been deposited by close‐spaced sublimation using Ga2Te3 powder source. However, the samples exhibit an excess of Te, as well as undesired Mo–Te compounds, when AgGaTe2 is deposited on Mo/glass substrates. Therefore, the AgGaTe2 light‐absorbing layer is deposited using an Ag2Te and GaTe mixed powder source and examined herein. By replacing the Ga2Te3 source with GaTe, the Te content confirmed by the X‐ray fluorescent has significantly decreased. Cross‐sectional transmission electron microscopy observation indicates that the formation of Mo–Te compounds is suppressed. This is because Ga2Te3 produces additional Te gas in the initial decomposition reaction during deposition, and GaTe does not. In addition, the J–V curves show an improved conversion efficiency for solar cells fabricated using GaTe. [ABSTRACT FROM AUTHOR]

Aluminum‐based chalcopyrite materials have attracted attention because of the wide controllability range of their material properties and potential for use in energy‐conversion devices. Herein, CuAlSe2‐based thin‐film growth and solar cell device properties are discussed. Ternary CuAlSe2 thin films are relatively unstable and decompose weeks after film growth, even when preserved in a dry box. However, alloying with elemental In led to significant improvements in stability. Cu(In,Al)Se2 (CIAS) solar cells yield better photovoltaic performance than CuInSe2 cells, although the effective range of Al concentration that can improve device performance is narrower than that of elemental Ga in Cu(In,Ga)Se2 (CIGS). A decrease in the alkali metal concentration in CIAS films with increasing Al concentration is observed, indicating that the formation energy of alkali‐metal substitutional defects on the Cu site is high, and/or Al‐related complex defects formed are kinetically stable and difficult to replace with alkali metals once they form. Although the direct observation of alkali metals in the bulk (grain interior) of chalcopyrite CuInSe2 and CIGS films has been difficult to date, this result can serve as indirect evidence of the presence of alkali metals in the bulk of CuInSe2 films. [ABSTRACT FROM AUTHOR]

High‐efficiency Cu(In,Ga)Se2 solar cells rely on Ga grading to mitigate back surface recombination. However, the inhomogeneous absorber has drawbacks, including increased non‐radiative loss and inadequate absorption. Therefore, literatures demand a paradigm shift of using a hole‐transport layer to passivate the back surface. Herein, a functional hole‐transport layer is demonstrated as an alternative to Ga grading. The novel hole‐transport layer is prepared as a double‐layer: co‐evaporated CuGaSe2 covered by solution combustion synthesis prepared In2O3. As demonstrated by micrographs, elemental mapping, and photoluminescence spectroscopy, the oxide layer improves thermal stability and prevents Ga diffusion. However, during the absorber deposition, a complete ion exchange of In and Ga converts CuGaSe2/In2O3 into CuInSe2/GaOx. Incorporating this hole‐transport layer in co‐evaporated nongraded CuInSe2 solar cells leads to significantly increased minority carrier lifetime from 5 to 113 ns, yielding an 80 meV improvement in quasi‐Fermi‐level splitting. The devices exhibit improved open‐circuit voltage, as well as a promising fill factor of over 71%, indicating good hole‐transport properties. In these results, the passivation effect and good hole‐transport properties of the hole‐transport layer are experimentally demonstrated. Thus, high‐efficiency solar cells can be achieved by using a functional hole‐transport layer without relying on Ga grading. [ABSTRACT FROM AUTHOR]

This paper review presents a comparison between conventional leaching and advanced photochemical leaching processes and their potential for use in chalcopyrite leaching. Likewise, it presents an analysis of the differences between the advanced leaching processes, photoleaching and radical-leaching, indicating that the photochemical mechanisms (photooxidation/photoreduction and generation of radical oxygen species (ROS) and radical sulfur species (RSS)) would improve the oxidative dissolution of chalcopyrite, taking advantage of the high oxidizing power of free radicals. Initial experimental results of solar-assisted radical-leaching on chalcopyrite are presented, demonstrating that sulfate radicals (SO4−) allow copper to be leached at a rate 4.7 times higher than in the absence of radicals and sunlight. With these results, a radical-leaching process is presented for the first time, with a perspective toward the future development of a new hydrometallurgical route: solar-assisted radical-leaching. [ABSTRACT FROM AUTHOR]

The adsorption of a conductive mineral toward a collector changes its interface electrochemical property, implying the hydrophobization mechanism of froth flotation. Herein, the interface electrical behavior of chalcopyrite was investigated by in situ scanning electrochemical microscopy (SECM). And the results demonstrated that the treatment of N, N-diethyl-S-[2-amino-2-(hydroxyimino) ethyl] dithiocarbamate ester (DEAHEDTC) significantly reduced the tip feedback current i and heterogenous electron transfer rate constant k of chalcopyrite interface, implying the self-assembly of DEAHEDTC on chalcopyrite surface. The adsorption mechanism investigations further revealed that both DEAHEDTC's C(=NOH)-NH2 and N-C(=S) groups combined with the surface Cu atom(s) of chalcopyrite, leaving its hydrophobic groups outward against chalcopyrite. For the hydrophobic groups that are non-conducting, the electrochemical activity of chalcopyrite interface decreased. While the hydrophobization of DEAHEDTC returned a high flotation recovery of chalcopyrite particles. [ABSTRACT FROM AUTHOR]

The oxidative flotation separation of chalcopyrite from pyrite in weak alkaline seawater solution was investigated using potassium ferrate (K2FeO4) as the oxidizing reagent. The optimal K2FeO4 concentration of 0.25 kg/t was found to strongly depress pyrite (from 88.05% to 7.92%) but insignificantly influence chalcopyrite (remaining at around 93%). K2FeO4 oxidized pyrite to form hydrophilic Fe2O3, Fe(OH)3, FeOOH, and Fe2(SO4)3 that covering on pyrite surface to prevent the adsorption of collector sodium butyl xanthate (SBX), thereby depressing pyrite flotation. Although a small amount of hydrophilic species was formed on chalcopyrite surface after the addition of K2FeO4, some hydrophobic substances such as S22-/Sn2-/S0 were also observed, resulting in an unaffected overall floatability. Further, density functional theory (DFT) calculation proved that the activity of Fe on chalcopyrite surface was much lower than that on pyrite. Therefore, this study provides a green way to separate chalcopyrite from pyrite effectively in a low-alkali seawater system, which is of significance to the separation of sulfide minerals in the fresh water-lack areas. [ABSTRACT FROM AUTHOR]

In order to substantiate the possibility of obtaining glass–ceramics from glasses based on slags from the joint smelting of silicate nickel and copper pyrite ores, the crystallization ability of model samples (particle size < 0.1 mm) that are close in composition and structure to real prototypes was evaluated. Using the methods of differential scanning calorimetry (5–20 °C·min−1 heating rate) and X-ray powder diffraction, it was established that in an inert atmosphere, crystallization is accompanied by the formation of products, the crystalline part (46.6–71.6 mass%) of which is represented by associations of pyroxenes and anorthite. The primary crystallizing phase is pyroxene. The transition from iron-free to iron-containing sample leads to a change in the composition of pyroxene from enstatite to pigeonite, a shift in the range of formation of these associations from 826–1018 to 728–874 °C, and additional (966–1068 °C) formation of silica. Kinetic analysis (Ozawa–Flynn–Wall and multi-variate nonlinear regression methods) showed consecutive bulk nucleation of pyroxenes and anorthite with the formation of two- and one-dimensional nuclei by a chain mechanism, passing into diffusion-controlled two- and three-dimensional crystal growth. The activation energy of enstatite nucleation (671 kJ·mol−1) is significantly higher than for pigeonite (418 kJ·mol−1), and for crystal growth (444 and 534 kJ·mol−1, respectively), the reverse relationship is noted. Pyroxenes promote the heterogeneous nucleation of anorthite. The activation threshold for the release of the latter in an iron-free sample (220 kJ·mol−1) is three times higher than in an iron-containing one (76 kJ·mol−1). The formation of two- and one-dimensional silica nuclei in the bulk of glass is synchronized with their two-dimensional growth under conditions of diffusion deceleration. The results obtained can be used in the development of technologies for producing glass–ceramics from various types of technogenic and mineral raw materials. [ABSTRACT FROM AUTHOR]

Although the flotation separation of sulfides and their electrochemical interactions have been examined in some investigations, study the direct relationship between the flotation kinetics of sulfides and their galvanic interactions during the process yet has not been addressed. To fill this gap, an extensive study was conducted to explore the effect of galvanic interactions for chalcopyrite and pyrite on their flotation kinetics when they are wetting ground by three different grinding media types (steel, chromium, and ceramic). Assessment of the flotation test results indicated that there was no galvanic interaction between the ceramic grinding balls and chalcopyrite. The galvanic interactions were mostly related to the grinding of chalcopyrite by steel balls. EDTA analysis showed that by increasing the amount of iron oxy/hydroxy and their precipitations on the surface of chalcopyrite, the recovery of chalcopyrite was decreased. Furthermore, increasing the pyrite content in the flotation of chalcopyrite increased the flotation rate constant and then decreased it. Flotation tests demonstrated that grinding chalcopyrite by ceramic media type, which has lower electrochemical activity in comparison with the other considered media, can be resulted in a higher flotation rate constant and ultimate recovery. Grinding the mixture of chalcopyrite and pyrite by steel or chromium media can show almost the same effect on the flotation rate constant and ultimate recovery. In general, the experimental results showed that by increasing the galvanic interaction, the flotation recovery and flotation kinetics were decreased. [ABSTRACT FROM AUTHOR]

A group of hypothetical compounds Mg2NA (A = F, Cl, Br, I) with the antichalcopyrite structure is considered. Optimized geometries, structures and compositions of the band spectra at all high-symmetry points of the first Brillouin zone are determined for all compounds. A qualitative and quantitative analysis of chemical bonds is performed using electron density distributions, the electron localization function, and Wannier functions. [ABSTRACT FROM AUTHOR]

The demand for non-ferrous copper metals has increased dramatically with the development of the global economy; accordingly, some refractory copper sulfide ores with low grade and their associated minerals are beginning to be utilized, making the flotation separation of copper concentrates exceptionally difficult, especially the separation of chalcopyrite and pyrite. In this paper, S-allyl-O, O′-dibutyl phosphorodithioate (ADTP) was synthesized by a one-pot method and used as a chalcopyrite collector in the flotation separation of chalcopyrite and pyrite. Flotation experiments results have shown that ADTP exhibits better selectivity and greater collecting power for chalcopyrite under neutral or weak base conditions. The 95% recovery of chalcopyrite can be achieved at pH 8.0 and 8.0 mg/L ADTP. From the analysis results of the contact angle, the SEM-EDS spectrogram, and elemental mapping, it was found that ADTP adsorbed uniformly on a chalcopyrite surface and made a significant contribution to the hydrophobicity of the surface. Confirmed by FTIR and XPS analysis, ADTP was able to form P–S–Cu bonds on a chalcopyrite surface, proving that it was adsorbed on the chalcopyrite surface in the form of chemisorption. [ABSTRACT FROM AUTHOR]

Ag-Pb-Cu mixed concentrate is a product ofcopper and lead floating and contains a silver grade of 4208.0 g/t, along with 3.3% of copper and 43.28% of lead. And 98.80% of silver is deposited in galena. The surface of the concentrate has been heavily contaminated with the flotation reagents, leading to a little difference in the floatability between galena and chalcopyrite. Consequently, separating chalcopyrite from galena is very difficult. In this experimental study, a combined process of removing the flotation reagents by activated carbon and flotating copper by the suppression of lead was adopted to treat the concentrate. By using a high-efficiency galena inhibitor (GYC) and chalcopyrite collector (SAC), an effective recovery of silver, lead and copper from the mixed concentrates was achieved. After the treatment of the mixed concentrate, the silver grade in obtained silver-lead concentrate was 4839.2 g/t with a recovery rate of 97.36% and the grade of lead was 50.05% with a recovery rate is 97.90%. In obtained copper concentrate, the silver grade was 724.6 g/t with a recovery rate of 2.64% and the copper grade was 20.16% with a recovery rate of 91.23%. [ABSTRACT FROM AUTHOR]

Chalcopyrite ore is one of the most abundant and pertinent oxidized copper minerals. In this research, the dissolution kinetics of chalcopyrite in an ammonia solution was examined. During leaching, the influences of leachant concentration, temperature, and particle diameter on the extent of copper ore dissolution were investigated. However, it was affirmed that the dissolution efficiency of chalcopyrite ore increased with decreasing particle fraction and increasing reaction temperature and ammonia concentration. About 68.6% copper ore dissolution was achieved with 2.0 mol/L NH3, 75 ºC reaction temperature, and 45 μm particle diameter within 120 minutes. The dissolution reaction mechanism was found to be described by diffusion-control with a calculated activation energy of 32.26 kJ/mol. In the XRD spectra of the residual product obtained at established conditions, CuFeS2 peaks were absent, indicating the leachability of the sample. Hence, the leach residue could serve as an important by-product for some local industries. [ABSTRACT FROM AUTHOR]

We present an investigation into the magnetism exhibited by AMY2 compounds characterized by a chalcopyrite structure, where A can be Cu or Ag, M can be Sc, Ti, V, Cr, Mn, or Fe, and Y can be either S or Se. By substituting M atoms at the Ga position of AGaY2 compounds, the magnetic properties were calculated using the full potential linearized augmented plane wave method under the generalized gradient approximation and local spin density approximation with the WIEN2K code. The obtained spin-polarized results confirmed the presence of ferromagnetic and half-metallic (HM) properties in AMY2 compounds (A = Cu, Ag; M = Ti, V, Cr, Mn; Y = S, Se), wherein the HM property is preserved through p-d hybridization of p states of Y (S, Se) atoms with d (t2g) states of M (M = Ti, V, Cr, Mn) atoms, and minimal contribution of −s states of A (A = Cu, Ag) atoms. The total magnetic moments for AMY2 compounds were calculated as 1.00, 2.00, 3.00, and 4.00 µB/f.u. for M = Ti, V, Cr, Mn, respectively. For AFeY2 compounds (A = Cu, Ag; Y = S, Se), electronic band structures for both up spin and down spin states were identical, suggesting antiferromagnetic behavior at equilibrium, while AScY2 compounds (A = Cu, Ag; Y = S, Se) exhibited nonmagnetic properties at equilibrium. Overall, the accurate HM properties of AMY2 materials suggest promising prospects for their utilization in spintronics and magnetic storage device applications. [ABSTRACT FROM AUTHOR]

The article presents the synthesis and application of a novel collector, 5-methyl butylxanthate-1,2,4-triazole-3-thione (MBuXTT), for chalcopyrite flotation separation from pyrite. Various interfaces and surface characterization analysis methods were employed to study the flotation separation mechanism. The micro-flotation and contact angle experiments demonstrated a significant enhancement in the surface hydrophobicity of chalcopyrite following treatment with MBuXTT. Within the pH range investigated, MBuXTT effectively enriched chalcopyrite while separating it from pyrite. Compared to the traditional collector sodium butyl xanthate, MBuXTT exhibited superior selectivity and collecting ability towards chalcopyrite. Adsorption of MBuXTT on the chalcopyrite surface was found to be an endothermic-spontaneous chemisorption process. ζ-Potential analyses and UV spectra confirmed specific adsorption of MBuXTT on chalcopyrite rather than pyrite surfaces. Additionally, FTIR, XPS, and DFT calculations were conducted to explore the adsorption mechanism on the chalcopyrite surface, and the results indicated that MBuXTT-Cu complexes can be covered on the chalcopyrite surface with formation of Cu(I)-S and Cu(I)-N bonds along with release of H+ and oxidation product formation involving S–S bonds. [ABSTRACT FROM AUTHOR]

The Shuangjianzishan silver polymetallic deposit is located in the copper–tin–lead–zinc–silver polymetallic metallogenic belt in the Southern Great Xing'an Range, with silver resources of more than 18,000 t, which is the largest silver polymetallic deposit in Asia. Early studies concluded that the Shuangjianzishan deposit is typically an epithermal Ag-Pb-Zn deposit that lacks a high-temperature mineralization stage. In recent years, with the deepening of research, a large amount of Cu-Sn mineralization has been found in the deep part of the Shuangjianzishan deposit, but it is less studied. The laser-ablation inductively coupled mass spectroscopy (LA-ICP-MS) technique is used to investigate the distribution and substitution of trace elements in chalcopyrite and cassiterite. In this paper, the trace element study of chalcopyrite and cassiterite from the Shuangjianzishan deposit reveals that Sn, In, As, Se, Sb, and Tl mainly exist in chalcopyrite in isomorphic form, while Pb, Bi, and Ni mainly exist in chalcopyrite in the form of mineral inclusions. The enrichment of the high-temperature elements Sn and Se in chalcopyrite, and the deficit of the middle- and low-temperature elements Ga, Sb, etc., reflect that the chalcopyrite in the Shuangjianzishan deposit was formed in a middle- and high-temperature environment, and it also indicates that the early ore-forming hydrothermal solution may be rich in Sn. Fe, In, Co, and Ni mainly exist in cassiterite in isomorphic form, and the content of W in cassiterite is high. There are two main forms, one is isomorphic and the other is wolframite inclusion. Cassiterite has Fe-rich and W-U-poor characteristics, indicating that cassiterite from the Shuangjianzishan deposit was formed under relatively oxidized conditions, and the relative enrichment of elements such as Fe, W, Zr, and Hf indicates that the temperature of cassiterite formation was high. The elemental content and inter-ionic coupling relationships suggest that the cassiterite from the Shuangjianzishan deposit may have an elemental replacement mechanism of W6+ + Fe2+ ↔ 2Sn4+ or Fe3+ + OH− ↔ Sn4+ + O2−. The trace elements in cassiterite of the Shuangjianzishan deposit are rich in Fe and Mn and depleted in Nb and Ta, according to the Fe-W diagram, and the tin mineralization of the Shuangjianzishan deposit belongs to cassiterite–sulfide-type tin mineralization. Chalcopyrite Co/Ni ratios >1 are consistent with the characteristics of chalcopyrite genesis in hydrothermal deposits. [ABSTRACT FROM AUTHOR]

A specific regime of continuous slow cooling of melted isocubanite CuFe2S3 from 1020 °C to 638 °C is realized, and then the crystallized ingot is quenched. This regime ensures both equilibrium crystallization of primary phases and their subsequent non-equilibrium solid-phase transformations. A large series of samples cut along a 90 mm long ingot are studied by optical and electron microscopy, powder XRD, and the stoichiographic differential dissolution method. Phase compositions are determined by the electron microprobe analysis. It is established for the first time that isocubanite releases cubic chalcopyrite rather than tetragonal one upon cooling in the following order: first cationic ordering of the isocubanite matrix and then steady metastable coherent pre-precipitations of cubic chalcopyrite in the matrix to finally transform into polycrystals free from the matrix. [ABSTRACT FROM AUTHOR]

Designing effective strategies for mitigating energy crisis highlights a research gap in current solar cell technologies. This study explores the inherent physicochemical properties of thin films composed of copper gallium sulfide telluride (CuGa1−xCrx(S,Te)2) with chromium substitution, prepared through the chemical spray pyrolysis technique. The investigation showcases how the concept of intermediate band structuring contributes to enhancing solar cell efficiency. This enhancement can be attributed to the remarkable mobility (from 1.80 to 5.48 cm2 V−1 s−1) and conductivity (from 1.00 to 6.06 S cm−1) exhibited by pure and 0.1 chromium thin films, respectively. Notably, the Cr‐0.1‐substituted CGST film displays maximum photoresponsivity of 0.624 AW−1, an external quantum efficiency of 145%, and a detectivity of 2.37E10. The fabricated solar cell is subjected to theoretical simulation using solar cell capacitance simulator‐1D software, revealing an upward trend in efficiency from 7.13% to 11.23% with increasing Cr substitution from 0.025 to 0.1. This efficiency improvement can be ascribed to the reduction in bandgap (from 2.40 to 1.72 eV) and the creation of a sub‐band in CGST due to Cr incorporation, as substantiated by UV–vis and NIR spectroscopy. These outcomes suggest that Cr‐0.1‐substituted CGST holds promise as a potential thin film absorber material in solar photovoltaics. [ABSTRACT FROM AUTHOR]

Sodium dithionite (Na2S2O4) is a widely used reducing agent to control pulp potential (Eh) and pyrite depressant in sulfide ore flotation. In this study, the pyrite depressant effect of sodium dithionite on gold ore flotation was investigated at pH 8 and pH 10.5 comparatively in terms of gold, chalcopyrite, and pyrite recoveries and grades. The presence of sodium dithionite resulted in a drop of approximately 50–70 mV in the Eh values, regardless of the studied pH values, confirming the reducing effect of sodium dithionite. The effects of sodium dithionite on gold and chalcopyrite grades and recoveries were quite limited, especially at pH 10.5. At pH 8, the utilization of sodium dithionite slightly decreased gold and chalcopyrite recovery and grades, while the decrease in pyrite recovery and grades was remarkable. Both pyrite recovery and grade were reduced from 79.5% to 54.7% and 15.3% to 10.7% by the utilization of sodium dithionite at pH 8. In conclusion, it is considered that the selective flotation of gold and chalcopyrite from pyrite can be achieved at a lower pH accompanied by a slightly reduced Eh by the utilization of sodium dithionite.

This work focuses on the synthesis and properties of quaternary ZnSnP2-yAsy chalcopyrite solid solutions. Full miscibility of the solid solution is achieved using ball milling followed by hot press sintering. The measured electrical conductivity increases substantially with As substitution from 0.03 S cm−1 for ZnSnP2 to 10.3 S cm−1 for ZnSnAs2 at 715 K. Band gaps calculated from the activation energies show a steady decrease with increasing As concentration from 1.4 eV for ZnSnP2 to 0.7 eV for ZnSnAs2. The Seebeck coefficient decreases significantly with As substitution from nearly 1000 μV K−1 for ZnSnP2 to −100 μV K−1 for ZnSnAs2 at 650 K. Thermal conductivity is decreased for the solid solutions due to alloy phonon scattering, compared to the end members with y = 0 and y = 2, with the y = 0.5 and y = 1.0 samples exhibiting the lowest values of 1.4 W m−1 K−1 at 825 K. Figure of merit values are increased for the undoped solid solutions at lower temperatures when compared to the end members due to the decreased thermal conductivity, with the y = 0.5 sample reaching zT = 1.6 × 10−3 and y = 1 reaching 2.1 × 10−3 at 700 K. The largest values of the figure of merit zT for the undoped series was found for y = 2 with zT = 2.8 × 10−3 at 700 K due to the increasing n-type Seebeck coefficient. Boltztrap calculations reveal that p-doping could yield zT values above unity at 800 K in case of ZnSnAs2, comparable with ZnSnP2. [ABSTRACT FROM AUTHOR]

The presented main studies of point defects in CdGa2Se4 chalcopyrite are considered to quantify the formation energies of three possible models of Cd, Ga and Se vacancy defects using various local density approximation (LDA) and general gradient approximation (GGA) approximations. Using supercells with 56 atoms, interatomic distances were calculated both for an ideal cell and a supercell containing vacancies. It was found that interatomic distance does not change only in a supercell containing Ga vacancy. Investigation shows that the Ga vacancy has a high defect formation energy (DFE) among other intrinsic vacancies and is therefore unstable. We found that for all vacancies, − 2 charge states are favorable. [ABSTRACT FROM AUTHOR]

In the flotation separation process of a Cu-Mo-W polymetallic ore, the wastewater from the scheelite cleaning flowsheet contains large numbers of residual flocculants and metal ions, and the separation of chalcopyrite and molybdenite requires a large number of environmentally harmful depressants. Therefore, it is necessary to find new methods to reduce the environmental and cost pressures of wastewater treatment and the use of depressants. In this work, the flotation wastewater from the scheelite cleaning flowsheet for the separation of chalcopyrite and molybdenite by selective surface passivation was investigated for the first time. Flotations of single minerals and artificially mixed minerals with or without immersion pretreatment in the presence and absence of aeration were performed. The results showed that pulp pH had no effect on the flotation of either mineral, and a molybdenite recovery of 93.22% with a chalcopyrite recovery of 10.77% was achieved under the conditions of 10 days of immersion pretreatment with aeration, 350 mg/L of kerosene, and 100 mg/L of MIBC. By combining the electrochemical cyclic voltammetry analysis and characterization by XRD and SEM, the selective surface passivation mechanism of chalcopyrite was discussed, which could be due to the coverage of the insoluble oxidation products, especially jarosite. This work has simultaneously achieved the depressant-free flotation separation of molybdenite and chalcopyrite and the reuse of scheelite flotation wastewater, which is of great significance for environmental protection and cost saving. [ABSTRACT FROM AUTHOR]

The separation of chalcopyrite and pyite is not fully solved, and thus more efficient depressants are still needed in industry. This paper used potassium permanganate (KMnO4) as a pyrite depressant to separate pyrite from chalcopyrite. Flotation and contact angle results indicated that pyrite could be depressed by KMnO4 at pH 7, while KMnO4-treated chalcopyrite could be floated by sodium ethylxanthate. For the pyrite-chalcopyrite mixture, the recovery of chalcopyrite was nearly 95% and that of pyrite was less than 15% when minerals were reacted with 4 × 10−4 KMnO4 for 3 min. The KMnO4-treatment raised the zeta potential of pyrite at pH 7, which may generate oxidized species on the pyrite surface. The oxidation products on the pyrite surface were FeO, FeOOH, and Fe2(SO4)3 as determined by XPS analyses. These oxidation products were well coated on the pyrite surface, which dramatically lowers the hydrophobicity of pyrite. In contrast, in the case of chalcopyrite, KMnO4 treatment did not generate new oxidation components on its surface, causing the chalcopyrite surface to remain hydrophobic and allowing the flotation of chalcopyrite by air bubbles. Thus, pyrite could be efficiently separated from chalcopyrite using KMnO4 as a depressant. [ABSTRACT FROM AUTHOR]

To find out the effect of the rare earth doping element Holmium (Ho) on CuInS2 thin films, various studies have been carried out and the results have been reported in this paper. The PL study shows that intensity of doped film is more than undoped film. The PL emission peak appears at 570–580 nm. SEM images of CIS:Ho (4 ml) film shows agglomeration on the surface. Both synthesized film of CuInS2 appears to be amorphous in nature with chalcopyrite structure as clear from XRD. Hall measurement and optical studies were also performed. [ABSTRACT FROM AUTHOR]

The geological structural patterns and hydrothermal alteration zones of Atauro Island, Timor-Leste, which are influenced by the collision mechanism between the Banda Arc and the Australian Continent, are the subject of this study. The study identifies fault types and alteration zones through stereographic analysis. It indicates the possibility of mineralisation in the area. Four alteration zones were identified in this study: argillic, Propylitic, calcosite, and geotite. The analysis results show that left-striking and normal faulting were essential in forming these zones. The mineralisation zones, mainly chalcopyrite and chalcocite, are related to the north-northeast trending left horizontal Fault. In addition, this study suggests additional research that includes mineralogy, geochemical, and geophysical analyses to understand more about the characteristics of hydrothermal alteration zones and possible mineralisation on Atauro Island. The results of this study are expected to improve our understanding of mineral resources in the region, and it is suggested that this information be considered by authorities responsible for the management of potential natural resources on Atauro Island, Timor. [ABSTRACT FROM AUTHOR]

The Kodaro–Udokan region is a huge Cu metallogenic province in Southern Siberia, one of the largest on Earth. It contains world-class copper sandstone-hosted Udokan (Cu reserves of 26.7 Mt) and PGE-Ni-Cu Chineysky deposits related to gabbro–anorthosite pluton (Cu—10 Mt; Fe-Ti-V, 30 Gt of ore). Furthermore, there are many small deposits of sulfide ores in sedimentary and igneous rocks in this region as well. For many decades, their genesis has been hotly debated. We studied the mineral composition and the sulfur isotopes in several deposits located at different levels of the stratigraphic sequence and in gabbro intruded in sandstones of the Udokan complex. The differences in ore compositions were found. The Burpala and Skvoznoy deposits consisting of the chalcocite–bornite association are characterized only by negative δ34S. The δ34S values for the Udokan deposits are mostly <0 (up to −28‰). The positive δ34S data characterize the ores of the Chineysky and Luktursky intrusions. Two Cu sandstone-hosted deposits are characterized by complex ore composition, i.e., the Krasny deposit, comprising chalcopyrite–pyrrhotite ores, is enriched in Co, Ni, Bi, Sb, Mo, Pb, Zn, Se, Te, and U and has a wide range of δ34S = −8.1–+13.5‰, and the Pravoingamakitsky deposit (Basaltovy section), consisting of quartz–chalcopyrite veins, has high PGE contents in ores with δ34S = +2.9–+4.0‰. These deposits are located near the gabbro massifs, and it is supposed that their ore compositions were influenced by magmatic fluids. The general regularities of the localization of the deposits in rift zones, and the proximity of mineral and isotopic composition allow us to conclude that the main source of copper could be rocks of basic composition because only they contain high Cu contents. Fluids from deep zones could penetrate to the surface and form Cu sandstone-hosted deposits. [ABSTRACT FROM AUTHOR]

The difference in chalcopyrite's primary ore-hosting rocks (dolomite and carbonaceous slate) in the Democratic Republic of the Congo results in an extremely uneven grain size distribution. Additionally, the presence of 2.21% organic carbon in the gangue impacts flotation efficiency. To address these challenges, ore properties were analyzed using the Mineral Liberation Analyzer (MLA), X-Ray Diffractometer (XRD), and microscopy. Flotation process was modified to incorporate a "middlings regrinding" processing, utilizing PDEC (an alkyne-based thioester collector, prop-2-yn-1-yl diethylcarbamodithioate) as the collector for experimental studies. Density Functional Theory (DFT) calculations elucidated the interaction mechanism of PDEC on chalcopyrite's surface. The MLA analysis indicates that chalcopyrite is mainly found in medium to fine grains, with the presence of fine-grained copper minerals smaller than 0.04mm accounting for 16.29% of the sample. This implies that these minerals require fine grinding for effective separation. Despite interference from organic carbon, PDEC demonstrates remarkable selectivity and efficiency in chalcopyrite flotation. By employing the "middlings regrinding" flotation method, a concentrate with a Cu content of 26.79% and a recovery of 87.88% was achieved, representing an increase of 0.17% in Cu grade and 4.09% in recovery rate compared to the conventional flotation process. DFT analysis demonstrates that the S 3p orbitals in carbon-sulfur double bond of PDEC and the C 2p orbitals in its acetylene group significantly affect its collection efficiency, engaging in hybridization with the Fe 3d orbitals on the surface of chalcopyrite, thereby facilitating a robust bonding interaction. [ABSTRACT FROM AUTHOR]

S‐Fe‐Cu isotope systems are powerful tracers for revealing geochemical processes. However, the microanalysis of S‐Fe‐Cu isotopes is critically limited by the lack of suitable reference materials. Herein, we present three potential reference materials Ll‐Cpy (chalcopyrite), Ll‐Po (pyrrhotite) and Ll‐Sp (sphalerite) for in situ S‐Fe‐Cu isotope measurements. Numerous in situ S‐Fe‐Cu isotope measurements were performed over two years to assess isotopic homogeneity. The bulk S isotopic compositions were determined independently in seven laboratories by isotope ratio mass spectrometry (IRMS); the preferred δ34SV‐CDT for Ll‐Cpy, Ll‐Po, Ll‐Sp are 6.13 ± 0.37‰ (2s), 6.42 ± 0.37‰ (2s) and 6.28 ± 0.38‰ (2s), respectively. The bulk Fe isotope ratios in Fe‐bearing Ll‐Cpy and Ll‐Po were determined using solution nebulisation multi‐collector inductively coupled plasma‐mass spectrometry, and the obtained δ56FeIRMM‐014 values are 0.57 ± 0.07‰ (2s) and ‐0.62 ± 0.07‰ (2s), respectively. The mean bulk δ65CuNIST SRM 976 value of Ll‐Cpy is 0.57 ± 0.06‰ (2s). All the bulk values are in good agreement with the long‐term statistical results of laser ablation‐MC‐ICP‐MS and proposed as the recommended values. These sulfides are well characterised and isotopically homogeneous (at 30–40 μm spatial resolution), and can be used as potential calibration materials for in situ S‐Fe‐Cu isotope measurements. [ABSTRACT FROM AUTHOR]

Professor Joseph "Joe" Greene taught me a great deal about research, leadership, and how to succeed. He was a mentor and a tireless advocate for me over the course of my career. This article summarizes some of the work that my research group carried out, inspired by Prof. Greene but not in direct collaboration with him. Three examples of these efforts are provided, epitaxial growth of Cu(In,Ga)Se2 (CIGS) on GaAs by sputter deposition, synthesis of Cu-Mo metastable alloys by sputter deposition, and recrystallization of CIGS deposited at high rates by treatment with metal halides. These works were carried out with many collaborators who are acknowledged in the description of the research carried out by them and in the references where full details can be found. [ABSTRACT FROM AUTHOR]

The luminous transmittance and the color rendering index of daylight through semitransparent photovoltaic glazing are essential parameters for visual comfort indoors, and they must be considered for different absorber materials that were traditionally developed for opaque solar cells, such as those of the chalcopyrite type. With this aim, various chalcopyrite compounds (CuInSe2, CuInS2 and CuGaS2) were prepared by means of evaporation and then measured to obtain their optical absorption spectra. These experimental data are used here to calculate the solar absorptance (αS), luminous transmittance (τL) and color rendering index (Ra) as a function of the chalcopyrite film thickness. The comparative analysis of the different factors indicates that 70 nm thick CuInSe2 is optimal to guarantee excellent visual comfort (τL = 50% and Ra = 93%) while absorbing as much solar irradiance (αS = 37%) as 130 nm thick CuInS2 or 900 nm thick CuGaS2. The second option (130 nm thick CuInS2) is also considered good (τL = 40% and Ra = 80%), but for CuGaS2, the thickness should be kept below 250 nm in order to obtain a suitable color rendering Ra ≥ 60%. [ABSTRACT FROM AUTHOR]

The chalcopyrite compound CuGa(In)Te2 has garnered significant attention due to its safe elemental composition and high thermoelectric potential. Optimizing the carrier concentration and reducing the lattice thermal conductivity of CuGa(In)Te2 can significantly enhance its thermoelectric performance. In this mini-review, we analyze the electronic and phonon structures of CuGa(In)Te2, summarize and categorize the representative methods employed in recent years to improve its thermoelectric performance. Our analysis reveals that reducing thermal conductivity has a more significant impact on enhancing the ZT value of CuGa(In)Te2 compared to increasing the power factor. In conclusion, we outline potential challenges and provide a brief outlook, offering valuable insights into the design of CuGa(In)Te2 chalcopyrite compounds as high-performance thermoelectric materials. [ABSTRACT FROM AUTHOR]

Oxidative leaching, as a basic step of the hydrometallurgical process of pure copper production from chalcopyrite, is a slow process in which mineral acids with strong oxidants addition are usually used as a leaching medium. It was found experimentally that the copper leaching from chalcopyrite in the H2SO4–H2O2–H2O system, in the presence of isopropanol (IPA) and under other conditions (H2O2 concentration, rate of mixing and temperature), takes place with satisfactory rate and efficiency. To quantify how much the change of these crucial variables affects the rate of the process, experimentally obtained kinetic curves (conversion over time) were analyzed using a Shrinking Core Model (SCM). The determined values of the copper leaching rate constants (kobs) confirmed the positive influence of increasing IPA and H2O2 concentrations as well as the temperature on the kinetics and efficiency of the leaching. The kinetic studies were also supported by using X-ray diffraction (XRD), 57Fe Mössbauer spectroscopy, scanning electron microscopy (SEM), and adsorption measurements. The positive influence of IPA was explained by its stabilizing role for iron compounds (hematite, magnetite, and pyrite), which are catalysts during the Cu dissolution, as well as H2O2 protection from decomposition during free radical reactions. Finally, the optimal conditions for efficient leaching, the rate-limiting step as well as the mechanism suggestion of the copper dissolution, were given. [ABSTRACT FROM AUTHOR]

Ternary chalcopyrite compound cupper indium disulfide (CuInS2)‐based photovoltaic cells are designed and numerically computed. In this design, n‐CdS and p++‐MoS2 have been used as window and back surface field (BSF) layers, respectively. The modeled n‐CdS/p‐CuInS2/p++‐MoS2 device provides power conversion efficiency (PCE) of 24.6% with JSC of 26.98 mA cm−2, VOC of 1.05 V, and fill factor (FF) of 86.93%. This efficiency is ≈60% higher the than n‐CdS/p‐CuInS2 single heterostructure. Furthermore, the use of a second CuInSe2 (CIS) absorber layer between CuInS2 absorber and MoS2 BSF layer significantly enhances the short‐circuit current. As a result, the current expressively improves to 38.48 mA cm−2, yielding an efficiency of 32.4%. The greater built‐in potential in absorber/BSF interface is attributed to the high JSC and VOC, causing the increment of efficiency. Besides, the photon management by Bragg reflector with 90% back and front reflectance recycling effect further increases the PCE to 36.1%. This work indicates the prospects of CuInS2 solar cells with a CuInSe2 current augmenter and MoS2 BSF layers for the fabrication of efficient CuInS2 solar cells. [ABSTRACT FROM AUTHOR]

This study presents the results of a two-stage autoclave processing of a copper–arsenic concentrate. Copper concentrate is an important raw material to produce copper and other metals. However, in some cases, the concentrate may contain increased amounts of arsenic, which makes further processing difficult. Therefore, the development of modern hydrometallurgical methods for processing copper concentrate with a high arsenic content is an urgent task, which could lead to the optimization of the raw material processing process and the improvement of the quality of the concentrate. It has been established that the optimal conditions for the sequential two-stage autoclave processing of copper–arsenic concentrate are: t = 220–225 °C, τoxidation = 20 min, τtot = 90 min, Po2 = 0.4 MPa, and L:S = 10:1, [H2SO4]initial = 40 g/dm3; in this case, 85% of zinc, 44% of iron, and 78% of arsenic, respectively, are extracted into the solution during both stages and the loss of copper was about 0.01%. This is explained by the fact that at the first stage (oxidation) of the autoclave processing of the copper–arsenic concentrate, copper, together with iron, leaches into the solution, and at the second stage (reduction), copper precipitates out of the solution in the form of chalcocite. Copper in the residue after autoclave leaching is in the form of Cu2S, iron is in the form of pyrite (FeS2), and lead is in the form of anglesite (PbSO4), respectively. The obtained micrographs and EDX mappings clearly show no iron arsenates. This confirms that at the oxidative stage of the developed process, arsenic, removed by 78%, remains in the solution. The remaining arsenic is associated with tennantite, indicating the effectiveness of the treatment process in removing arsenic from the copper–arsenic concentrate. A second important observation is the presence of pronounced areas of copper sulfides in the microphotos without iron and arsenic impurities. This confirms that copper is deposited as chalcocite during the reduction phase of the process, which is the desired result. [ABSTRACT FROM AUTHOR]

This manuscript presents a model and simulation of the copper chalcopyrite semiconductor CuGaSe2 in order to predict its magnetic properties. In the semiconductor material CuGaSe2 (CGS), the atom Cu is the only magnetic element with a magnetic moment value S = 1/2. We propose a Hamiltonian to calculate the energies corresponding to different configurations of the system. In a first step, we presented the magnetization behavior by using the Monte Carlo simulations (MCS). The magnetizations as a function of the temperature, the exchange coupling have been studied and discussed. We have also deduced and studied the magnetic susceptibilities. To complete this study, we have established and discussed the magnetic hysteresis loops of the studied compound. Finally, we have calculated the corresponding critical exponents and compared them with the standard 3D Ising model. [ABSTRACT FROM AUTHOR]

In mineral processing, arsenic-bearing minerals are particularly difficult to separate from their non-arsenic counterparts because they possess similar surface properties. Peptides are well known for their target specificity and can offer a 'green' alternative to traditional flotation reagents. However, the use of peptide technologies in mineral processing for developing novel flotation reagents has not been explored. Hence, this work aims to develop a screening method to identify mineral-binding peptides as potential reagent candidates. It is hypothesised that peptides can selectively adsorb onto mineral surfaces, and this method can efficiently identify mineral-binding peptides with high specificity toward the target minerals. The methodology presented involves a selection of peptide candidates from existing literature that show affinity toward arsenic species. These peptides were tested for their adsorption performance onto selected mineral surfaces to evaluate their mineral selectivity under flotation conditions. The study demonstrates that the screening method developed is effective in identifying peptides that have an affinity for target minerals, in this case, arsenic minerals. The screening method can be applied to other minerals, thus, unlocking the potential for developing new reagent chemistries for use in mineral processing. [ABSTRACT FROM AUTHOR]

Galvanic interactions present alternative strategies to achieve a more efficient Cu dissolution from CuFeS2. The present work studied the interaction between chalcopyrite–magnetite (CuFeS2-Fe3O4) in acidified ferric sulphate Fe2(SO4)3-H2SO4 at a solution pH of 1.8 and a temperature of 25 or 50 °C. The addition of Fe3O4 to CuFeS2 forms a galvanic couple, which positively impacts the dissolution of Cu. The results showed that the presence of Fe3O4 led to high and fast Cu dissolution rates and decreased significantly the activation energy, from 83 to 57 kJ/mol. In addition to that, the solid residues revealed that CuFeS2 dissolution produced intermediate Cu-S-rich phases: CuS, Cu2S and Cu5FeS4, which appeared to envelop CuFeS2, had no observable intermediate phase while in the presence of Fe3O4. The results showed that 94% of Cu could be recovered after 5 h of leaching at 50 °C at a Fe3O4/CuFeS2 ratio of 4:1 and a 460 mV Ag/AgCl solution potential. The findings of this study present an option for efficient Cu dissolution from CuFeS2 in ferric sulphate at atmospheric pressure. [ABSTRACT FROM AUTHOR]

In the current study, the leaching conditions of chalcopyrite/pyrite concentrate were optimized by sulfuric acid and hydrogen peroxide using response surface methodology (RSM). The optimal leaching conditions were found to be a sulfuric acid concentration of 150 g/L, a hydrogen peroxide volume of 350 mL, a temperature of 80 °C, a leaching time of 8h and a solid–liquid ratio of 0.52 g/mL. After analysis of variance (ANOVA), the sulfuric acid concentration and temperature were the most significant process variables for the leaching concentrations of both copper and iron. Under the optimum conditions, the recovery of copper and iron was 81.83% and 67.57%, respectively. [ABSTRACT FROM AUTHOR]

The efficient separation of chalcopyrite (CuFeS2) and galena (PbS) is essential for optimal resource utilization. However, finding a selective depressant that is environmentally friendly and cost effective remains a challenge. Through various techniques, such as microflotation tests, Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) observation, X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy measurements, this study explored the use of ferric ions (Fe3+) as a selective depressant for galena. The results of flotation tests revealed the impressive selective inhibition capabilities of Fe3+ when used alone. Surface analysis showed that Fe3+ significantly reduced the adsorption of isopropyl ethyl thionocarbamate (IPETC) on the galena surface while having a minimal impact on chalcopyrite. Further analysis using SEM, XPS, and Raman spectra revealed that Fe3+ can oxidize lead sulfide to form compact lead sulfate nanoparticles on the galena surface, effectively depressing IPETC adsorption and increasing surface hydrophilicity. These findings provide a promising solution for the efficient and environmentally responsible separation of chalcopyrite and galena. [ABSTRACT FROM AUTHOR]

Magnetic separation has been proposed to greenly separate chalcopyrite and talc several decades ago, due to their extremely similar floatability of minerals. However, this approach was not achieved initially due to the inadequately magnetic induction of traditional magnetic separation, and fine particle size of chalcopyrite. Currently, the development of highly magnetic induction technology provides strong feasibility for this separation. In this work, we employed pulsating high-gradient magnetic separation (PHGMS) with highly magnetic induction (1.8T) to separate chalcopyrite and talc, and found that the PHGMS achieves a good separation of chalcopyrite from talc. But the chalcopyrite recovery decreased with the decrease of its particle size, and thus surface oxidation treatment was attempted to increase the magnetism and magnetic capture of ultrafine chalcopyrite. As a result, an increment of approximately 10 % was observed in the recovery of ultrafine chalcopyrite post-oxidation. As verified by the superconducting quantum interference device measurements, the oxidized ultrafine chalcopyrite exhibited a significant increase in the saturation magnetisation intensity, remanent magnetisation and coercivity values. Such magnetism enhancement is a result of the formation of paramagnetic Fe(III)–O–OH structures on the oxidized chalcopyrite surface, in terms of X-ray photoelectron spectroscopy and Mössbauer spectroscopy investigations. Furthermore, the density functional theory revealed that the formation of Fe(III)–O–OH structures caused a substantial increase in the magnetic moments of iron ions in antiferromagnetic chalcopyrite. These findings may extend the application of magnetic separation, and facilitate the flotation of ultrafine chalcopyrite from other minerals, at significantly reduced reagents use, and productive and environmental costs.