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The critical metal germanium (Ge) is recovered as a by-product of mining other commodities, such as zinc and thermal coal. We investigated the Ge incorporation mechanism in sphalerite synthesized under hydrothermal conditions like those of sediment-hosted Zn-Pb deposits. Sphalerite ± galena ± barite formed via reactions of Ge ± Fe ± Cu ± Ba-bearing brine with calcite and reduced sulfur at 200 °C and water vapor-saturated pressure. The products were examined using backscattered electron (BSE) imaging, electron probe microanalysis (EPMA), electron backscattered diffraction (EBSD), synchrotron X-ray fluorescence (SXRF) and micro-X-ray absorption near-edge structure (μ-XANES). We show that Ge(IV) is incorporated into sphalerite and bonded with reduced sulfur, both in the experimental sphalerite and in natural zinc ore samples from the MacArthur River Zn-Pb-Ag deposits, Australia. Copper K-edge XANES spectra show that copper occurs as Cu(I) in the experimental sphalerite, consistent with previous studies on Cu in natural sphalerite. The experiments reveal that Ge(IV) substitution in sphalerite occurs with and without the presence of other metal ions (e.g., Cu(I)), indicating that Ge(IV) substitution can be accommodated via charge balance by vacancies as well as by coupled substitution in the synthesized sphalerite. Ab initio quantum chemical simulations confirm that sphalerite can readily accommodate Ge, with the crystal structure and average Zn-S, Zn-Zn, S-S distances retained when replacing > 3 mol% of the Zn sites with Ge(IV), Ge(II), Cu(I) or Fe(II), demonstrating the resilience and flexibility of the sphalerite crystal structure. These Ge incorporation mechanisms explain the previous observations of multiple ways of Ge incorporation in natural sphalerite. The study provides experimental and molecular simulation insights for understanding the processes related to the formation and extraction of Ge in zinc ores. [ABSTRACT FROM AUTHOR]

The Youjiang basin is a diamond-shaped Indosinian foreland basin formed during the subduction and merging of the South China plate into the Indo-Chinese plate. A large number of Indo-Chinese tectonic traces have been preserved in the basin. However, little has been reported about the syn-tectonic magma and its related mineralization in the basin. Sphalerites from the newly discovered Deli Pb-Zn deposit in the Xidamingshan mining district at the southeastern margin of the Youjiang basin were sampled for the Rb-Sr isochron dating. We obtained the isochron age of 207.1 ± 0.6 Ma (MSWD = 1.5) with initial Sr isotopic composition of 0.728379 to 0.739226. The Sr isotopic compositions are distinct from those of the Late Cretaceous felsic intrusions and the Late Jurassic high-Mg andesite in or around the Xidamingshan district but similar to those of the Late Triassic granites in the Guangxi province. The results indicate that the ore-forming age of the Deli Pb-Zn deposit may be closely related to the concealed Triassic granite. The Si-Ca fracture zone between the Devonian and Cambrian is a favorable location to search for Pb-Zn deposits in the Xidamingshan mining district. This work proves the Triassic Pb-Zn mineralization has occurred in the Xidamingshan mining district and Late Cretaceous magmatic-hydrothermal Bi-W-Zn-Pb-Ag mineralization in the west of it. It provides new ideas and directions for future exploration in the Xidamingshan mining district. [ABSTRACT FROM AUTHOR]

This study investigated the abandoned Balya Pb–Zn mine tailing in Turkey. We performed sieve analyses, X-ray diffraction (XRD), scanning electron microscopy–energy dispersive X-ray spectroscopy (SEM–EDS), major and trace element analyses, and SEM-based quantitative mineralogical analyses on collected samples. A schematic oxidation model comprising at least three stages is proposed based on the mineral paragenesis, textural properties of minerals, and elemental deportments. Oxidation caused the development of vertical zones such as vadose (oxidation) and capillary zones with physical, mineralogical, and chemical differences. For example, the near-surface vadose zone of sulfide oxidation contained intensely oxidized pyrite (18 wt.%) and 16 wt.% secondary minerals (As-bearing plumbojarosite, jarosite and gypsum). In contrast, the capillary zone representing a depth of 20–60 cm contained unaltered 13 wt.% pyrites, primary sulfides (e.g., sphalerite, galena, and arsenopyrite), and 23 wt.% secondary Mn–Fe–Zn-bearing oxy-hydroxides. The distribution of secondary minerals also reflected the elemental mobility depending on pH. Precipitation of plumbojarosite under acidic conditions limited the mobility of Pb and As, thereby keeping them in the vadose zone. Mn, Fe, and Zn seeped deep, and their mobility was limited by forming oxy-hydroxides at moderately acidic to circumneutral pH conditions in the capillary zone. The precipitation of the secondary minerals changed the textural properties of primary sulfides such as pyrite and galena restricted their reactivity, and caused a change in the rate and degree of oxidation over time. This case study showed that mineralogical constituents, key factors in the characterization of mine tailings, may change due to the secondary minerals, as in historical tailings with a long exposure time. Therefore, it should be noted that assessments based on the existing mineralogical properties of unoxidized tailing samples may cause uncertainties in determining the long-term behavior of the tailings. [ABSTRACT FROM AUTHOR]

In this study, the crystalline structure and particle shape of Cd1−xMnxS (x~0.3) in the composite photocatalysts prepared by hydrothermal synthesis at different temperatures (T = 80, 100, 120, and 140 °C) were analyzed. Along with mixed Cd–Mn sulfide, the catalysts contain a small amount of β-Mn3O4. XRD patterns of (Cd,Mn)S have features inherent to both cubic zinc blende and hexagonal wurtzite structure. Moreover, XRD peaks are anisotropically broadened. First, the heterogeneous (or two-phased) model was considered by the commonly used Rietveld method. Phase ratio, average crystallite sizes, and strains for both phases were formally determined. However, it was shown that this model is not correct because relatively narrow and broad peaks cannot be fitted simultaneously. Then, the homogeneous model was tested by Debye Function Analysis. This model assumes that particles are statistically homogeneous, but each particle contains lamellar intergrowth of zinc blende and wurtzite modifications. The probability of stacking faults, as well as the average radii of spherical and ellipsoidal particles, were varied. It was shown that nanocrystalline Cd0.7Mn0.3S particles have an ellipsoidal shape. Ellipsoids are elongated along the direction normal to the plane of defects. An increase in the hydrothermal synthesis temperature from 80 °C to 140 °C leads to an enlargement of particles and a gradual decrease in the probability of stacking faults in the wurtzite structure from 0.47 to 0.36. Therefore, with increasing temperature, the structure of (Cd,Mn)S nanoparticles transforms from almost random polytype cubic/hexagonal (ZB:WZ = 47:53) to a preferably hexagonal structure (ZB:WZ = 36:64). Mn2+ ions facilitate CdS phase transformation from zinc blende to wurtzite structure. There is no direct correlation between the structure and photocatalytic activity. [ABSTRACT FROM AUTHOR]

A complex crystal-chemical investigation based on spectroscopic methods, Electron MicroProbe Analysis (EMPA), and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) was made on sphalerite samples from the Terézia and Rozália veins in the Banská Štiavnica ore district. The yellow (sample A) and olive-green sphalerite (C) are in association only with quartz; orange sphalerite (B) is associated with quartz and chalcopyrite; and black sphalerite (D) is associated with galena, chalcopyrite, quartz, and baryte. EMPA revealed that Cd and Fe are substituting for Zn with variable proportions; the Cd/Fe ratio decreases from 2.82–2.85 in the A sample to 0.42 in the D sample. LA-ICP-MS showed that, except Cd and Fe, only Mn has content above 20; Co and Cu vary between 2 and 17 ppm. The optical absorption spectra exhibit absorption between 644 and 740 nm with three smaller humps at 669–671, 698–702, and 732–743 nm, and weaker absorption bands at 858–894 nm in the NIR region, which can be all assigned to crystal-field transitions of Fe2+. The absorption edge starts at about 600 nm to the UV region. Minimal absorption is in the yellow-red part of the visible spectrum giving rise to yellowish-orange and orange-red colors. Absorption in the red region for olive-green sphalerite is more pronounced, explaining the shift to greenish hues. In black sphalerite, the absorption pattern is similar to the olive-green sphalerite, but the bands in the 644 to 740 nm region are less defined. The black color could be caused by slightly higher concentrations of Fe, the smaller size of individual crystals in the aggregate reducing macroscopic transparency, and/or the presence of submicroscopic inclusions. [ABSTRACT FROM AUTHOR]

To eliminate the unwanted activation of Zn sulphide by dissolved Pb SP 2+ sp from PbSO SB 4 sb , Aikawa et al. [[8]] suggested pretreating the Cu-Zn-Pb ore by washing it in ethylene diamine tetra acetic acid (EDTA) to dissolve PbSO SB 4 sb and the subsequent cementation of dissolved Pb by zero-valent iron (ZVI). To meet the high forecasted demand, unconventional sources of metals such as low-grade complex ores, seafloor massive sulphides (SMSs), and wastes (e.g., tailings, metallurgical residues, and electronic wastes (e-wastes)) have become very important sources of metals [[3]]. The depletion of high-grade and easy-to-process ore has led to researchers exploring complex ores, such as Cu-Zn-Pb sulphide ore, for the recovery of valuable minerals. However, the liberation and later concentration of metals from e-waste, particularly from printed circuit boards (PCBs), is difficult because of the layered structure of non-metal (i.e., epoxy resin, glass fibre) and valuable metals (e.g., Cu). [Extracted from the article]

Fluorite is a widespread mineral in porphyry and hydrothermal vein Mo-polymetallic deposits. Here, fluorite is utilised as a probe to trace the fluid source and reveal the fluid evolution process in the Chalukou giant Mo (Pb–Zn) deposit, Northeast China, which is characterised as early porphyry Mo and later vein-style Zn–Pb mineralisation. A detailed rare earth element (REE) and Sr–Nd isotope study of fluorite combined with Sr isotopes of sphalerite is conducted for the Chalukou deposit. The chondrite-normalised REE patterns of fluorites from molybdenite veins show light REE (LREE)-enriched patterns, with negative Eu anomalies (δEu = 0.60) and weakly negative Y anomalies (Y/Y* = 0.72). The fluorites associated with sphalerite veins exhibit rare earth element (REE)-flat patterns with negative Eu anomalies (δEu = 0.65 to 0.99) and positive Y anomalies (Y/Y* = 1.37 to 3.08). In addition, during the progression from Mo to Zn–Pb mineralisation, the total concentration of REEs decreases from 839 ppm to 53.7 ppm, and Y/Ho ratios increase from 22.1 to 92.5. These features may be explained by the different mobilities of REE complexes during fluid migration. The Eu anomalies are considered to be inherited from source fluids. All the initial 87Sr/86Sr ratios of fluorite and sphalerite are between those of ore-forming porphyries and wall rocks (rhyolite), with fluorite ratios ranging from 0.706942 to 0.707386 and sphalerite ratios varying from 0.705221 to 0.710417. The majority of εNd(t) values of fluorite varying from −6.4 to −3.6 are also located between the ratios exhibited by ore-forming porphyries and rhyolite, whereas three εNd(t) values of fluorites ranging from −0.26 to 0.36 are close to those of ore-forming porphyries. All the isotopic features indicate that the Sr-Nd isotope ratios of hydrothermal fluid are derived from porphyries and disturbed by fluid–rock reactions. Together with a two-stage Sr–Nd isotope mixing model, we suggest that different sources and fluid–rock interactions (syn-ore intrusions and strata) finally influence the Sr–Nd isotopes of the ore-forming fluids, which are recorded by the majority of fluorite and sphalerite. [ABSTRACT FROM AUTHOR]

The relationship between the grinding characteristics of polymetallic complex ore and its component minerals, pyrrhotite, sphalerite, and quartz, under the action of abrasion was studied, based on batch grinding experiments and theoretical analysis methods of selective grinding. The results show that when the polymetallic complex ore was subjected to the action of abrasion, the crushing effect of ore was enhanced by the existence of sphalerite, that is, sphalerite plays a positive role in the crushing effect of ore. The crushing effect of ore was reduced by the existence of pyrrhotite and quartz, that is, pyrrhotite and quartz plays a negative role in the crushing effect of ore. In addition, the sphalerite had a more prominent effect on the grinding characteristics of the ore. The grinding speed of ore and its component minerals decreased exponentially with the grinding time, and the instantaneous grinding speed of 0 min was negatively correlated with the feed sizes. The rapidly decreasing trend of the grinding speed reached the threshold when the grinding time reached 4 min. The results can provide some theoretical guidance for the study of grinding characteristics of multi-component complex ores in subsequent grinding process. [ABSTRACT FROM AUTHOR]

Lateral sampling of each blasting interval (~ 2.6 m) along a 79 m strike length was conducted for the Hosen 8‐2 vein on the −5 ML (mining level, meters relative to sea level) of the Main ore zone in the Hishikari epithermal Au deposit, Kagoshima, Japan. The horizontal variation of mineral textures, bulk chemical compositions, and fluid inclusion temperatures and apparent salinity of ore fluids were determined. The major gangue minerals of the quartz veins studied include quartz and adularia with minor amounts of calcite and smectite. The major ore minerals include electrum, galena, and sphalerite with minor pyrite, petzite, and hessite. Electrum commonly occurs in a discrete band with microcrystalline quartz, granular adularia, and smectite. The electrum‐bearing band is followed by tabular adularia, and finally by granular or comb quartz. Mineral textures that indicate high degrees of supersaturation with respect to amorphous silica (presently quartz with microcrystalline/mosaic and feathery textures) and adularia (with tabular, rhombic, and granular textures) were common throughout the vein strike. Bulk chemical analyses indicate that Au grade is positively correlated with Ag, Bi, Pb, and Te contents. A bonanza zone with Au grades up to 10,800 ppm occurs in the central part of the Hosen 8‐2 vein on the −5 ML, and is associated with high adularia content, calculated as adularia / (quartz + adularia). The wide lateral variation in the geochemical composition contrasts with the consistent association of electrum with microcrystalline quartz, granular adularia, and smectite throughout the Hosen 8‐2 vein on the −5 ML. Fluid inclusion microthermometry of primary and pseudosecondary inclusions in quartz and adularia yielded histogram modes of homogenization temperature between 160 and 240°C; the most frequent mode is 200–210°C, with most data within ±10°C from this value. The maximum ice‐melting temperature of most samples excluding late comb quartz is −1.5°C, which is equivalent to an apparent salinity of 2.6 wt% NaCl eq. The wide variation in ice‐melting temperatures and apparent salinities (up to 5.2 wt% NaCl eq.) may be due to dissolved CO2 in the fluids, while the sharp decrease in apparent salinity with temperature decrease indicates CO2 loss due to fluid boiling during vein formation. The intimate association of electrum with microcrystalline quartz that recrystallized from amorphous silica indicate sharp boiling and vapor loss as the primary mechanism of Au deposition in the Hosen 8‐2 vein. [ABSTRACT FROM AUTHOR]

The Castellanos Zn-Pb deposit in northwest Cuba is hosted by black shales intercalated in the upper part of a thick siliciclastic sequence (>4km) mainly made up of sandstones and siltstones of Lower to Middle Jurassic age (San Cayetano Formation). The ore deposit is tabular to wedge-shaped and stratiform, oriented NE-SW conformably with the stratification of the host black shales and appears splitted into two blocks (the Farallones block to the NE and the Susana block to the SW) by a N120°Eoriented fault zone; a similarly oriented fault zone marks the NE contact of the Farallones block. This block overlies a stockwork zone made up of <10cm-thick, pyrite-chalcopyrite-quartz veins striking N120°E too. The orebody consists of pyrite, sphalerite and galena, with carbonates (mainly dolomite-ankerite and calcite), quartz, and barite, as well as minor percentages of sericite, partly altered biotite and cryptocrystalline apatite. The internal structure is zoned and consist of a discontinuous, lower pyrite-rich level overlayed by a heterogeneous ore level with variable sulfide+carbonate (locally with quartz) modal proportions, as well as variable amounts of sphalerite+galena relative to pyrite. The upper level shows a broad banded texture defined by alternating pyrite-rich, sphalerite+galena and dolomite-ankerite (±sericite, partly altered biotite and cryptocrystalline apatite) bands, which becomes better defined towards the SW part of the orebody. Modal proportions of quartz and to a lesser extent barite increase too from NE to SW and from bottom to top, especially within the Susana block. An additional NE-SW trend is observed in the chemical composition of sphalerite, whose Fe content decreases southwestwards; this Fe-poor sphalerite coexists with a second generation of sphalerite containing even lower Fe (<1wt.%). Different events of fracturing and brecciation affected the sulfide ore near the N120°E oriented fault zones, which promoted precipitation and remobilization of several generations of calcite, barite, quartz and galena. The late events also allowed precipitation of chalcopyrite filling fractures and interstitial spaces among fragments of the previous sulfide ore. The proposed genetic interpretation of the Castellanos orebody is based on the repeated (multiphase) precipitation of sulfides+carbonates due to the interaction between ore-forming brines migrating upwards through the stockwork fractures and organic matter-rich sediments deposited in an anoxic sub-basin developed in the major passive-margin basin where the sandstones and siltstones of the San Cayetano Formation accumulated. The ore-forming brines were oxidizing, saturated in sulfate, and generated in the evaporite-bearing carbonate platform developed at the margins of the passive-margin basin from Upper Jurassic to Lower Cretaceous times. The infiltration of these brines through the thick siliciclastic sequence gave rise to a significant increase in temperature (up to 100-200°C), thus promoting dissolution and remobilization of the Zn and Pb quantities necessary to form the main sulfide ore. The fracturing and brecciation stages enabled upward migration of reduced fluids equilibrated with black shales intercalated at different levels of the siciliclastic sequence, which, in turn, supplied Au and Ba to the ore. Late fracturing also allowed ascent of deep, hot fluids (~350°C) capable of precipitating chalcopyrite. [ABSTRACT FROM AUTHOR]

The influence of an external magnetic field on the complex elastic moduli of crystals with a sphalerite or zinc blende (ZnSe) and wurtzite (CdSe) structure lightly doped by Cr2+ ions has been investigated. Measurements have been performed in the frequency interval 26–32 MHz at 1.4 K. In II–VI crystals, bivalent chromium cations are triply orbital-degenerate in the ground state and, being in a tetrahedral environment, produce Jahn–Teller complexes. These complexes are described in terms of the T (e + t2)-problem and exhibit the adiabatic potential energy surface with the global minima of tetragonal symmetry. It has been found that in ZnSe:Cr2+ crystals, a magnetic field directed along the [001] and [110] axes influences modulus (c11 – c12)/2 and does not influence modulus c44. In CdSe:Cr2+ crystals, however, moduli c55 and c66, which are the analogs of (c11 – c12)/2 and c44, depend on the magnetic field directed along the [ ] and [ ] axes, respectively. The discovered anomalous behavior of the elastic moduli with magnetic field has been treated in terms of a model that takes into account the crystal field, vibronic and spin-orbital interactions, and the contribution of the Jahn–Teller subsystem to isothermal moduli determined at a constant magnetic induction. Good agreement with experimental dependences of the elastic moduli in strong magnetic fields has been obtained, and it has been shown that the nonmonotonic variation in weak magnetic fields (below 2 T) should be associated with a magnetic field dependence of the relaxation time. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) and boron nitride (BN) are well‐known ceramic materials with numerous valuable properties, whereas recently there is a growing field of research on the AlN/BN advanced ceramic materials. Here, we present a study on boron‐rich AlN, structural and electronic properties, and structure–property relationship. Several AlxB1−xN solid solutions (x = 1,.875,.75, and.625) have been investigated, and structure optimization has been performed for four different structure types: h‐BN, wurtzite, sphalerite, and rock salt. First‐principles calculations were performed using hybrid B3LYP functional. New modifications and compounds have been predicted as a function of boron concentration in AlN, and especially, interesting phase transitions were found at extreme pressure conditions. Electronic properties and band structures were computed, and the possibility for bandgap tuning has been discovered. The present study, and especially the structure–property relationship, gives new possibilities for bandgap engineering in boron‐rich AlN electroceramic materials. [ABSTRACT FROM AUTHOR]

Surface energetics of zinc sulfide nanoparticles determines their structure, properties, and occurrence. Using a combination of experimental techniques, we investigated the thermodynamics of the two polymorphs, sphalerite and wurtzite at bulk and nanoscale to understand their occurrence. Calorimetric measurements confirmed that wurtzite has a lower surface energy than sphalerite, which causes a reversal in phase stability at the nanoscale, with wurtzite energetically stable for particle size below 10 nm. Taking these surface energies into account, a simple model of the thermodynamics of the sphalerite - wurtzite transformation as a function of particle size and temperature can explain the occurrence of the zinc sulfide polymorphs in environments as diverse as ore bodies and planetary atmospheres. [ABSTRACT FROM AUTHOR]

Arsenic is a harmful element in a silver-lead-zinc polymetallic ore in Yunnan. The occurrence state of arsenic and its effect on beneficiation are quickly and accurately identified by means of optical microscope and automated mineral analyzer such as AMICS. The results show that the arsenic content is 0.53%, and the arsenic is mainly distributed in arsenopyrite, followed by pyrite, partly distributed in realgar and gratonite. However, the main factor leading to the high arsenic content of silver-lead concentrate is that realgar and gratonite, followed by arsenopyrite. In order to reduce the arsenic content, the depression of realgar and arsenopyrite should be strengthened. Gratonite and galena are closely related and have similar chemical properties, and they are difficult to be effectively separated, so the arsenic content in silver-lead concentrate can hardly be reduced to less than 0.77%. The main factor leading to the high arsenic content of sulfur concentrate is arsenopyrite and arsenic-bearing pyrite. Even if pyrite and arsenopyrite are separated effectively, the arsenic content can hardly be reduced to less than 0.22%. For zinc concentrate, sphalerite is relatively easy to separate from arsenopyrite and pyrite, so the arsenic content is easy to reach the standard. The research results provide a theoretical basis for arsenic reduction process of the arsenic-bearing Ag-Pb-Zn polymetallic deposit in Yunnan. [ABSTRACT FROM AUTHOR]

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The 90 ° and 30 ° partial glide dislocations in ZnS are investigated theoretically in the framework of the fully discrete Peierls model and first-principles calculation. It is found that there are four types of equilibrium cores for each kind of partial glide dislocation, which are named as the O-Zn-core, the B-Zn-core, the O-S-core, and the B-S-core, according to their geometrical feature and atomic ingredient at the core. For the 90 ° partial dislocation, the O-Zn-core (double-period core) and the B-S-core (single-period core) are stable. The Peierls barrier heights of the O-Zn-core and the B-S-core are about 0.03 eV/Å and 0.01 eV/Å, respectively. For the 30 ° partial dislocation, the O-Zn-core (double-period core) and the B-Zn-core (single-period core) are stable and their Peierls barrier heights are approximately the same as that of the O-Zn-core of the 90 ° partial dislocation. The Peierls stress related to the barrier height is about 800 MPa for the 90 ° partial dislocation with the B-S-core. The existence of unstable equilibrium cores enables us to introduce the concept of the partial kink. Based on the concept of the partial kink, a minimum energy path is proposed for the formation and migration of kinks. It is noticed that the step length in kink migration is doubled due to the core reconstruction. [ABSTRACT FROM AUTHOR]

Colloidal crystals provide a versatile platform for designing phononic metamaterials with exciting applications for sound and heat management. New advances in the synthesis and self-assembly of anisotropic building blocks such as colloidal clusters have expanded the library of available micro- and nano-scale ordered multicomponent structures. Diamond-like supercrystals formed by such clusters and spherical particles are notable examples that include a rich family of crystal symmetries such as diamond, double diamond, zinc-blende, and MgCu2. This work investigates the design of phononic supercrystals by predicting and analyzing phonon transport properties. In addition to size variation and structural diversity, these supercrystals encapsulate different sub-lattice types within one structure. Computational models are used to calculate the effect of various parameters on the phononic spectrum of diamond-like supercrystals. The results show that structures with relatively small or large filling factors (f > 0.65 or f < 0.45) include smaller bandgaps compared to those with medium filling factors (0.65 > f > 0.45). The double diamond and zinc-blende structures render the largest bandgap size compared to the other supercrystals studied in this paper. Additionally, this article discusses the effect of incorporating various configurations of sub-lattices by selecting different material compositions for the building blocks. The results suggest that, for the same structure, there exist multiple phononic variants with drastically different band structures. This study provides a valuable insight for evaluating novel colloidal supercrystals for phononic applications and guides the future experimental work for the synthesis of colloidal structures with desired phononic behavior. [ABSTRACT FROM AUTHOR]

The high-precision analytical study of sphalerites from Pitkäranta ore deposits used microprobe and La-ICP-MS analyses. Average concentrations of minor (Fe, Cu, Mn, Cd) and trace elements (In, Сo, Ni, Ga, Ge, As, Ag, Sn, Sb, Te, Au, Tl, Pb, Bi) in sphalerite were calculated from 169 analyses. It is shown that most analyzed elements are present in sphalerite as isomorphic components. The average content of In in sphalerite is 1927 ppm, and its maximum content is 1.5 wt %. The In-enriched sphalerite displays medium concentrations of Fe (3–6 wt % Fe), low Mn (300–400 ppm), and high Co (0.1–0.2 wt %). Parameters of the "indium window," favorable for indium penetration into the sphalerite crystalline lattice, according to the scheme Cu+ + In3+ ↔ 2Zn2+, correspond to 0.6–1.2% Cd. The highest In content in sphalerite is characteristic of chalcopyrite-free ore-bearing mineral assemblages. The sphalerite-chalcopyrite association is, however, typical of the proper indium mineral, roquesite. Sphalerite in this association is distinguished by a low indium content (260–657 ppm). Ratio of indium contents in sphalerite and chalcopyrite (InZn /InCu) in roquesite-bearing assemblages varies from 2 to 4, while in roquesite-free assemblages it is much higher (from 10 to 215). Indium distribution in the sphalerite samples, having also elevated contents of Cd, Ag, and Au, indicates that roquesite-free propylitized skarns with Sn–Zn–Fe mineralization in sites with relatively abrupt (40°–50°) dipping of the Salmi rapakivi massif roof, and without Li–F granites, are most perspective for indium and those other metals (Kitelä deposit, Kulismajoki and Hopunlampi ore occurrences). [ABSTRACT FROM AUTHOR]

In northern Tunisia, Sidi Driss sulfide ore valorization had produced a large waste amount. The long tailings exposure period and in situ minerals interactions produced an acid mine drainage (AMD) which contributed to a strong increase in the mobility and migration of huge heavy metal (HM) quantities to the surrounding soils. In this work, the soil mineral proportions, grain sizes, physicochemical properties, SO42− and S contents, and Machine Learning (ML) algorithms such as the Random Forest (RF), Support Vector Machine (SVM), and Artificial Neural Network (ANN) models were used to predict the soil HM quantities transferred from Sidi-Driss mine drainage to surrounding soils. The results showed that the HM concentrations had significantly increased with the increase of decomposition and oxidation of galena, marcasite, pyrite, and sphalerite-marcasite and Fe-oxide-hydroxides quantities and the sulfate dissolution (marked with SO42− ions increase) that produced the decreased soil pH. Compared to SVM, and ANN models outputs, the RF model that revealed higher R2val, RPD, RPIQ, and lower error indices had satisfactorily predicted the soil HM accumulation coming from the AMD environment. [ABSTRACT FROM AUTHOR]

In this paper, we studied the role of the crystal structure in spheroidal CdSe nanocrystals on the band-edge exciton fine structure. Ensembles of zinc blende and wurtzite CdSe nanocrystals are investigated experimentally by two optical techniques: fluorescence line narrowing (FLN) and time-resolved photoluminescence. We argue that the zero-phonon line evaluated by the FLN technique gives the ensemble-averaged energy splitting between the lowest bright and dark exciton states, while the activation energy from the temperature-dependent photoluminescence decay is smaller and corresponds to the energy of an acoustic phonon. The energy splittings between the bright and dark exciton states determined using the FLN technique are found to be the same for zinc blende and wurtzite CdSe nanocrystals. Within the effective mass approximation, we develop a theoretical model considering the following factors: (i) influence of the nanocrystal shape on the bright–dark exciton splitting and the oscillator strength of the bright exciton, and (ii) shape dispersion in the ensemble of the nanocrystals. We show that these two factors result in similar calculated zero-phonon lines in zinc blende and wurtzite CdSe nanocrystals. The account of the nanocrystals shape dispersion allows us to evaluate the linewidth of the zero-phonon line. [ABSTRACT FROM AUTHOR]

Present work investigates the ore mineralogy, geochemistry of host metasedimentary rocks, and the mineral chemistry of the main sulphide minerals, namely, sphalerite, chalcopyrite, galena, and pyrite from the Rangpo sulphide mineralization, Sikkim. Based on the textural relationships of the oxide and sulphide minerals such as mutual boundary, exsolution blebs, and replacement features, three stages including two stages of primary ore mineral formation, and an alteration stage of secondary mineral development is established. Oxide and sulphide minerals predominantly magnetite, chalcopyrite, sphalerite, galena, pyrrhotite, and cobaltite occur as stage‐I ore minerals, and the sulphide minerals namely galena, pyrrhotite chalcopyrite, arsenopyrite, sphalerite, and pyrite are identified as stage‐II minerals. The alteration minerals malachite and azurite represent stage‐III. The geochemistry of host metasedimentary rocks is characterized by SiO2 in the range of 53.28 to 85.62 wt%, Mg# values between 25.48 and 49.60, MgO and K2O having a strong negative correlation with SiO2, high values of Zr/Sc (32.5) versus Th/Sc (3.44), and enrichment of trace elements like Cr (30–87 ppm), V (27–81 ppm), Ni (13–49 ppm), and Sc (3–12 ppm). The Th/Sc versus Zr/Sc, K2O/Na2O versus SiO2, and Th/Co versus La/Sc plots attribute that the host metasedimentary rocks are recycled sediments largely of passive continental margin with a felsic source. However, the Mg# versus SiO2 and K2O/Na2O versus SiO2 point to the incorporation of mantle material from the orogenic margin, possibly arc‐related and mafic in nature. The features such as the mineral assemblage, the simultaneous crystallization shown by mutual boundaries and exsolution blebs, and the mineral chemical data of ore minerals favour a high‐temperature hydrothermal environment of ore deposition. This inference is substantiated by general high Fe concentration in sphalerite and other ore minerals, 800 to 2,400 ppm Cd in sphalerite, Ag and Sb in galena from 1,000 to 2,500 ppm and 400 to 800 ppm respectively, and noticeable Ag in chalcopyrite. The inferred depositional and tectonic environment of host metasedimentary rocks, the petrographic features of ores, and their mineral chemical data altogether invoke that the Rangpo ore mineralization in metasedimentary rocks was formed at high temperature in an environment where mafic mantle material from the active arc was amalgamated with the passive margin sediments derived from the felsic source rocks. [ABSTRACT FROM AUTHOR]

The effect of inorganic depressant zinc sulfate on the flotation of galena and sphalerite was investigated using micro flotation tests, and different addition orders of zinc sulfate and diethyldithiocarbamate were also studied. When zinc sulfate is added firstly, its depression effect on sphalerite is considerable, but on galena is weak. But when diethyldithiocarbamate is added firstly, zinc sulfate has little depression effect on galena flotation, whereas still strongly depresses sphalerite. The interaction between zinc sulfate and diethyldithiocarbamate on the sulfide surface was studied by adsorption measurement It is indicated that the diethyldithiocarbamate strongly absorbs on the galena surface, and zinc sulfate has no impact on the adsorption of diethyldithiocarbamate on the galena surface, while the adsorption of diethyldithiocarbamate on the sphalerite surface is weak. Infrared microspectrography analysis suggests that the addition of zinc sulfate decreases the adsorption of diethyldithiocarbamate on the sphalerite surface, which is the reason that zinc sulfate can depress sphalerite adsorbing diethyldithiocarbamate. The addition of zinc sulfate has little depression effect on the adsorption of the diethyldithiocarbamate on the galena surface, therefore can hardly depress the galena flotation. Time of flight secondary ion mass spectrometry (ToF SIMS) analysis suggests that as compared to the addition first of zinc sulfate, less zinc hydroxide hydrocolloids and more diethyldithiocarbamate are adsorbed on the galena surface, while more zinc hydroxide hydrocolloids and less diethyldithiocarbamate are adsorbed on the sphalerite surface, when diethyldithiocarbamate is added firstly, and so as to be more useful to realize the flotation separation of Pb Zn. [ABSTRACT FROM AUTHOR]

The article explores an alternative approach to understand the difference between lying and attempting to mislead without lying. It presents this criticism in the spirit of advancing the effort to work out interesting and viable alternatives. It further discusses definition of lying and how it falls short in illuminating the distinction between lying and misleading.

DFT calculations of the metal carbides MC (M = Ir, Rh and Ru) compounds in the rock-salt RS (B1) and Zinc Blende ZB (B3) phases were performed over the structural, elastic and thermodynamic properties. The exchange-correlation functional employed is the generalized gradient approximation of Wu and Cohen (GGA-WC). The structural parameters such as lattice constants (a0), bulk moduli (B0) and its pressure derivative () were calculated, and the values obtained are in excellent agreement with the experimental and theoretical results. The elastic constants (C11, C12 and C44), Shear modulus (G) and Young's modulus (E) have also been computed and then compared with the theoretical data reported in the literature. The thermodynamic properties of these compounds were estimated, and the effects of temperature and pressure upon the heat capacities, expansion coefficients and bulk modulus. The longitudinal, transverse and average sound velocities and Debye temperature of these compounds have also been calculated and analyzed. [ABSTRACT FROM AUTHOR]

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The flotation recovery of sphalerite depends on the inorganic reagents concentrations in the liquid phase of suspension and pH. This paper presents the results of studies of the interactions of iron (II) containing ions with the sphalerite surface in water solutions at different pH levels. The thermodynamic and electrochemical studies were carried out to analyze possible interactions of sphalerite with iron (II) sulfate in a water environment and relate them to sphalerite flotation with potassium butyl xanthate and sodium dibutyl dithiophosphate. The results of the thermodynamic calculations revealed the possibility of interaction of the sphalerite surface with iron (II) hydrolysis products. The effect of the hydroxide ions concentration on precipitation of iron (II) hydroxides was examined. The findings showed that at pH = 8 there were no precipitates observed in water solutions of FeSO4. Increasing pH of the solutions from 8 to 12 resulted in the formation of iron (II) hydroxides. The potentiometric studies revealed that in slightly alkaline solutions the Fe2+ and FeOH+ cations are potential-determining. In conclusion, the flotation tests with thiol collectors show the activation effect of iron (II) sulphate on sphalerite at low dosage and pH 12. This is evident by a higher flotation recovery of sphalerite at these conditions. [ABSTRACT FROM AUTHOR]

This study examined the electrodissolution mechanism of five impure sphalerite samples, which differ significantly in purity levels, along with their partially oxidized counterparts in a 0.5 M H 2 SO 4 . Partially oxidized samples were prepared through an incomplete leaching of sphalerite using H 2 SO 4 with Fe 2 (SO 4 ) 3 .H 2 O as an oxidizing agent. The original sphalerite samples and the partially oxidized samples were referred to as SP and POS samples, respectively. Analyses using XRD, SEM, Raman spectroscopy, and electrochemical techniques suggested presence of elemental sulfur and a metal-deficient layer on the surface of the POS samples. Cyclic voltammetry revealed that the sample with the highest iron content exhibited the highest electrochemical response, while the sphalerite with the highest lead concentration had the lowest activity. Electrochemical impedance spectroscopy (EIS) studies showed that impedance values were higher in the POS samples compared to the PS samples, indicating a correlation within the passivation phenomenon. In conclusion, these findings suggested that the sphalerite dissolution process is primarily controlled by charge transfer and kinetic polarization. This understanding can lead to the development of more selective and sustainable extraction methods and improving the overall economic viability of zinc hydrometallurgical operations., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

A suite of complementary techniques was used to examine germanium (Ge), a byproduct critical element, and co-substituent trace elements in ZnS and mine wastes from four mineral districts where germanium is, or has been, produced within the United States. This contribution establishes a comprehensive workflow for characterizing Ge and other trace elements, which captures the full heterogeneity of samples through extensive pre-characterization. This process proceeded from optical microscopy, to scanning electron microscopy and cathodoluminescence (CL) imaging, to electron microprobe analysis, prior to synchrotron-based investigations. Utilizing non-destructive techniques enabled reanalysis, which proved essential for verifying observations and validating unexpected results. In cases where the Fe content was

The nature of tennantite (Cu12As4S13), chalcopyrite (CuFeS2) and sphalerite (ZnS) particles' mixture dissolution in nitric acid (HNO3) media was investigated in this study. The effects of temperature (323–368 K), HNO3 (1–8 mol/L) and Fe3+ (0.009–0.036 mol/L) concentrations, reaction time (0–60 min) and pyrite (FeS2) additive (0.5/1–2/1; FeS2/sulf.conc.) on the conversion of the minerals were evaluated. It has been experimentally shown that the dissolution of the mixture under optimal conditions (>353 K; 6 mol/L HNO3; FeS2/synt. conc = 1/1) allows Cu12As4S13, CuFeS2 and ZnS conversion to exceed 90%. The shrinking core model (SCM) was applied for describing the kinetics of the conversion processes. The values of Ea were calculated as 28.8, 33.7 and 53.7 kJ/mol, respectively, for Cu12As4S13, CuFeS2 and ZnS. Orders of the reactions with respect to each reactant were calculated and the kinetic equations were derived to describe the dissolution rate of the minerals. It was found that the interaction between HNO3 solution and Cu12As4S13, CuFeS2 and ZnS under the conditions investigated in this are of a diffusion-controlled nature. Additionally, the roles of Fe(III) in the initial solution and FeS2 in the initial pulp as catalysts were studied. The results indicated that the increase in Fe3+ concentration significantly accelerates the dissolution of the mixture, while the addition of FeS2 forms a galvanic coupling between FeS2, and Cu12As4S13 and CuFeS2, which also accelerates the reaction rate. The results of the study are considered useful in developing a hydrometallurgical process for polymetallic sulfide raw materials treatment. [ABSTRACT FROM AUTHOR]

CdZnTe thin films were prepared on ITO glass by magnetron sputtering method to explore the effect of mechanical grinding and polishing on the resistive switching characteristics of CdZnTe thin films. Through the analysis of experimental results such as XRD patterns, Raman spectroscopy, AFM micrograph, etc., the physical mechanism of mechanical grinding and polishing affecting the resistive switching characteristics of CdZnTe thin film was elucidated. The results show that the thin films prepared by magnetron sputtering are sphalerite structures with F43m space group. Mechanical grinding and polishing improves the crystallization quality of CdZnTe thin films; the roughness (Ra) of CdZnTe film decreases from 3.42 nm to 1.73 nm after grinding and polishing. Transmittance of CdZnTe thin film after grinding and polishing and the vibration peak of CdTe-like phonon peaks at 162 cm-1 were enhanced. After grinding and polishing, the resistive switching ratio of CdZnTe thin film increases from 1.2 to 4.9. The reason why mechanical grinding and polishing improves the quality and resistive switching characteristics of CdZnTe thin films may be that CdZnTe thin films are recrystallize during the grinding process. [ABSTRACT FROM AUTHOR]

Pb–Zn mineralization at Rajpura‐Dariba and Zawarmala, India, is hosted in the Palaeoproterozoic meta‐volcano‐sedimentary sequence of Aravalli‐Delhi Belt. We have studied different generations of pyrite (Py‐I, II and III) and sphalerite (Sph‐I, II and III), associated with ore mineralization and remobilization stages, from both the deposits. In Rajpura‐Dariba, high concentrations of the majority of trace elements in syngenetic Py‐I and Sph‐I suggest their formation from trace element enriched hydrothermal fluid in SEDEX environment. Enrichment of lattice bound elements in Py‐II (As, Co, Ni) and Sph‐II (Mn, Hg and Cd) during metamorphic recrystallization of early pyrite and sphalerite indicates their local derivation from host rocks. The Pb, Tl, Ag and Sb rich Py‐III and Sph‐III in discordant ore indicate their crystallization from low melting‐point chalcophile elements enriched sulfide melt. In Zawarmala, the trace element poor natures of diagenetic banded Py‐I and Sph‐I suggest that the initial ore‐forming fluid was depleted in trace elements. Enrichment of trace elements in Py‐II (As, Mn, Tl, Cu) and Sph‐II (Mn, Hg, As, Ga) in sphalerite‐pyrite vein ore signify their derivation from carbonate host rocks. The high abundance of trace elements in Py‐III and Sph‐III indicates their precipitation at lower temperatures from a trace element enriched hydrothermal fluid during the massive galena‐sphalerite ore formation. Pyrite and sphalerite from global SEDEX are trace elements enriched as compared to MVT deposits, where their compositions have remarkably correlation with host rocks. Our study highlights the influence of host rock in pyrite and sphalerite compositions and their ore genetic implications. [ABSTRACT FROM AUTHOR]

Haerdaban is a newly discovered Zn–Pb deposit (0.64 Mt at 6.19 wt% Zn and 1.09 wt% Pb) in the Western Tianshan, NW China. Sulfide mineralization mainly occurs as veins, breccias, and semi-massive ores within the dolomitic limestone and calcareous slate. Here we use Rb–Sr sphalerite and SHRIMP U–Pb zircon geochronology to place constraints on the age and formation of the deposit. Rb–Sr dating of sphalerite gives an isochron age of 432 ± 45 Ma (n = 6; 87Sr/86Sri = 0.7102 ± 0.0020), providing a direct age constraint for the main mineralization. SHRIMP U–Pb data for detrital zircon from three samples of host siliceous dolomite have relatively similar age modes with prominent age peaks at 1576 Ma, 1781 Ma, and 1848 Ma, and a smaller peak at 1375 Ma. The maximum depositional age for the host dolomite is constrained at 1099 ± 21 Ma by the weighted mean age of the four youngest detrital zircons. These results demonstrate that the main mineralization clearly postdates the host sedimentary rocks. Zircons from two diorite samples and one granite sample yield overlapping 206Pb/238U ages with a weighted mean of 394.5 ± 1.5 Ma. This age is slightly younger but within analytical uncertainty of the 432 ± 45 Ma for the ores, implying a possible temporal relationship between intrusions and main mineralization. The igneous intrusions could provide the heat to drive the hydrothermal system responsible for main-stage mineralization. Haerdaban is interpreted to be a metamorphosed SEDEX Zn–Pb deposit that has been remobilized by subsequent hydrothermal activity. [ABSTRACT FROM AUTHOR]

Carbonate-hosted Pb–Zn deposits frequently contain significant amounts of critical metals such as germanium in sphalerite. However, the textural and chemical controls leading to Ge enrichment remain poorly constrained. Based on textural observations and laser-ablation (multi-collector) inductively coupled plasma mass spectrometry analysis, we investigate the origin, textural control, and incorporation of Ge in the Zhulingou carbonate-hosted Zn(-Ge) deposit, South China, which contains > 400t Ge at 97.9 ppm. Two hydrothermal stages (I and II) and three textural types of sphalerite (Sp1, Sp2, and Sp3) are recognized in stratabound and stockwork Zn(-Ge) orebodies. Acicular colloform Sp1 formed in stage I, whereas euhedral sector-zoned Sp3 is related to stage II. In acicular-euhedral Sp2, both Sp1 and Sp3 are observed. A large variation of Ge concentrations is observed with an average Ge of 1013 ppm in Sp1, decreasing to 621 ppm in Sp2 and to 492 ppm in Sp3. In the three types of sphalerite, Ge concentrations are not correlated to monovalent cations (Cu and Ag), indicative of unusual substitution mechanisms coupled to divalent cations such as Mn, Pb, or Cd. Trace element distribution, sulfur, and lead isotopes suggest that the deeply circulating brines interacted with Ge-rich basement rocks and mixed with shallow biogenic sulfur: This mixing process was certainly the main factor controlling the Ge endowment. The precipitation of acicular sphalerite was likely controlled by a combination of specific fluid conditions (i.e., low T and pH, and rapid mineral growth rate) and fluid mixing. These conditions leading to the formation of acicular sphalerite were favorable for Ge enrichment, compared to co-existing euhedral grains generally less rich in Ge. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ionoluminescence (IL) is introduced as an imaging technique which can reveal unique aspects of sample structure from depths of several tens of micrometers. Both 2-D and 3-D IL images of a natural sphalerite sample were provided and compared with the microscopic image and micro-PIXE 2-D and 3-D elemental based images of the sample. It was shown that IL images could present different structural aspects of the sample with a spatial resolution on the order of one micrometer. Regarding the capabilities of the IL imaging technique, it is suggested as a fast and non-destructive technique for structural investigation of different inhomogeneous samples. [ABSTRACT FROM AUTHOR]

The present study was carried out to show the potential of root exudates to mobilize potentially toxic elements (PTE) present in rhizospheric carbonated soils. Five different contaminated rhizospheric soils were collected from five former mining districts of northern Tunisia (Jebel Hallouf (H3), Sidi-Bouaouane (B1), Jebel Ghozlane (G7), Hammam Zriba (Z2) and Jalta (J2)). The abundant minerals in these soils are quartz, calcite and clays. These soils contain significant PTE amounts compared to the local geochemical background (LGB). The important concentrations of Pb, Zn, Cd, As and Sb are, respectively, in the order of 17,350 mg·kg−1 in B1, 37,000 mg·kg−1 in G7, 205 mg·kg−1 in G7, 683 mg·kg−1 in B1 and 145 mg·kg−1 in B1. Kinetic leaching tests were conducted with a mixture of low molecular weight organic acids (LMWAOs) for increasing times up to 16 h (initial pH = 2.8) to study the mobility of PTE in the rhizospheric soils. The results showed an increase in the pH of the solution (2.8) to values up to neutrality together with the increase in Ca and Mg concentrations in the leachate, resulting from the dissolution of carbonates (calcite and dolomite). Additionally, leaching tests showed important extractions of Cd and Zn (25% for Cd and 11% for Zn). Pb was also mobilized but to a lesser extent (5%). The extractability of metalloids (As and Sb) was, in contrast, relatively low, except for Jebel Hallouf and Sidi Bouaouane soils, with an extraction percentage of no more than 1% for Sb and 0.1% for As, respectively. The mobility of Zn, Pb and Cd was thought to be controlled by both the solubility of their host minerals (e.g., sphalerite, hemimorphite, cerussite and jordanite) and the high pH. In contrast, As and Sb mobility was dependent on secondary carrier phases such as iron oxyhydroxides. [ABSTRACT FROM AUTHOR]

Pb–Zn deposits supply a significant proportion of critical metals, such as In, Ga, Ge, and Co. Due to the growing demand for critical metals, it is urgent to clarify the different types of Pb–Zn deposits to improve exploration. The trace element concentrations of sphalerite can be used to classify the types of Pb–Zn deposits. However, it is difficult to assess the multivariable system through simple data analysis directly. Here, we collected more than 2200 analyses with 14 elements (Mn, Fe, Co, Ni, Cu, Ga, Ge, Ag, Cd, In, Sn, Sb, Pb, and Bi) from 65 deposits, including 48 analyses from carbonate replacement (CR), 684 analyses from distal magmatic-hydrothermal (DMH), 197 analyses from epithermal, 456 analyses from Mississippi Valley-type (MVT), 199 analyses from sedimentary exhalative (SEDEX), 377 analyses from skarn, and 322 analyses from volcanogenic massive sulfide (VMS) types of Pb–Zn deposits. The critical metals in different types of deposits are summarized. Machine learning algorithms, namely, decision tree (DT), K-nearest neighbors (KNN), naive Bayes (NB), random forest (RF), and support vector machine (SVM), are applied to process and explore the classification. Learning curves show that the DT and RF classifiers are the most suitable for classification. Testing of the DT and RF classifier yielded accuracies of 91.2% and 95.4%, respectively. In the DT classifier, the feature importances of trace elements suggest that Ni (0.22), Mn (0.17), Cd (0.13), Co (0.11), and Fe (0.09) are significant for classification. Furthermore, the visual DT graph shows that the Mn contents of sphalerite allow the division of the seven classes into three groups: (1) depleted in Mn, including MVT and CR types; (2) enriched in Mn, including epithermal, skarn, SEDEX, and VMS deposits; and (3) DMH deposits, which have variable Mn contents. Data mining also reveals that VMS and skarn deposits have distinct Co and Ni contents and that SEDEX and DMH deposits have different Ni and Ge contents. The optimal DT and RF classifiers are deployed at Streamlit cloud workspace. Researchers can select DT or RF classifier and input trace element data of sphalerite to classify the Pb–Zn deposit type. [ABSTRACT FROM AUTHOR]

In this paper, the adsorption of cyanide and its combination with zinc sulfate on the surface of sphalerite (110) was studied by density functional theory (DFT), and its configurational relationship was analyzed by coordination chemistry. The calculation results show that the adsorption configuration stability of CN− is stronger than that of Zn(CN)2; the chemical bond of Zn(OH)2 is less covalent. The three adsorption modes all make the surface of sphalerite lose more electrons, thereby weakening the reactivity of S and Zn atoms on the sphalerite surface. During the CN− adsorption process, both the 3d and 4p orbital peak energy levels of Zn decrease, indicating the strong inhibitory effect of CN−. Coordination chemistry also shows that CN− matches the Zn ion orbital in sphalerite and the π electron pair on the Zn ion can easily interact with the empty π orbital on CN− to form π-backbonding. [ABSTRACT FROM AUTHOR]

The strong contamination of the interface is the main problem that results in low flotation efficiency of sphalerite in cyanide tailings. However, the consumption of cyanide and dissolved oxygen, as well as the concentration of ions including Zn2+ and SCN− in the leaching solution, decreased with the use of ceramic ball medium. The conclusions obtained from SEM–EDS indicated that the use of ceramic ball medium avoided the excessive surface oxidation caused by the galvanic couple actions between the iron ball medium and the sphalerite. XPS analysis also proved that the chemical environment on the surface of sphalerite was optimized by porcelain ball medium compared with iron ball medium, avoiding the formation of Fe–OOH and Fe–O hydrophilic substances, especially [Fe(CN)6]3−, thus increasing the adsorption of the collector on the surface of sphalerite. Therefore, grinding with ceramic ball medium exhibited excellent performance in terms of the cyanide process, which was approximately 5–10% higher than that obtained by grinding with iron ball media in the flotation test. [ABSTRACT FROM AUTHOR]

Zinc smelting high sulfur residues is a dangerous waste residue produced by the zinc oxygen pressure leaching process. Due to the complex mineral phase and the lack of in-depth research on process mineralogy, it is difficult to safely utilize and dispose of high sulfur residues. The domestic typical high sulfur residue was studied in detail by chemical analysis, X-ray diffraction, process mineralogy and other research methods. The results show that the main minerals in high sulfur residues are elemental sulfur, sphalerite, pyrite, as well as trace amounts of quartz, muscovite, zinc vitriol and iron vitriol, etc. The minerals such as sulfur, sphalerite and pyrite in high sulfur residues are intertwined and symbiotic with each other in various forms, and most of the minerals use elemental sulfur as the inlaid base. The particle size of elemental sulfur, sphalerite and pyrite in high sulfur residues is fine, mostly concentrated below 74 μm. Therefore, increasing the particle size of elemental sulfur and the dissociation degree between sulfur and other minerals are the keys to improving the comprehensive recovery of valuable elements in high sulfur residues. [ABSTRACT FROM AUTHOR]

Various genetic models have been proposed for the supergiant Proterozoic Broken Hill Pb–Zn–Ag deposit largely based on geological and geochronological evidence. Here we present Zn, Cd and S isotope compositions as well as Zn/Cd ratios of sphalerite from Broken Hill and minor Broken Hill-type deposits (Australia) to help constrain these models but focus on syngenetic and magmatic–hydrothermal processes, since epigenetic models can be rejected because the orebodies were deformed and metamorphosed by the Olarian Orogeny. Values of δ34SVCDT, δ66ZnAA-ETH and δ114CdNIST SRM 3108 for sphalerite from Broken Hill range from +0.27 to +4.73 ‰, −1.15 to +0.46 ‰ and −0.48 to +0.01 ‰, respectively, while those for the smaller Broken Hill-type deposits range from −5.11 to +1.28 ‰, −0.97 to +0.10 ‰ and −1.02 to +2.59 ‰, respectively. By combining published S isotope data of sulfides from the Broken Hill district with those obtained here, the sources of sulfur via thermochemical sulfate reduction, bacterial sulfate reduction and a magmatic origin cannot be distinguished. However, when the S isotope compositions are considered along with the broad range of Cd and Zn isotope data for sphalerite, which are among the lightest and heaviest yet reported for a sulfide deposit, the isotopic datasets are consistent with low-temperature biogenic processes associated with syngenetic deposition of sulfides. Cadmium isotope compositions when coupled with Zn/Cd ratios of sphalerite have previously been used to classify Pb–Zn deposits, including low-temperature, high-temperature and exhalative ores. However, the Zn/Cd ratios of sphalerite from Broken Hill cannot be used for such classification purposes. [ABSTRACT FROM AUTHOR]

Here, we present a method, based on Stark shifts induced by the quantum-confined Stark effect, to directly determine the piezoelectric field in strained zinc-blende quantum wells (QWs) grown along the 111 direction and embedded in the p–i–n diode structure (p-iMQW-n) of a semiconductor optical amplifier. Under short-circuit and open-circuit conditions and resonant optical excitation, we experimentally determine the energy of the 1s e-hh excitonic resonance and the potential difference across the p-iMQW-n junction. Using these parameters in an analytical expression derived in this work, we directly determined a piezoelectric field of −108.71 ± 8.51 kV/cm acting on each of the eight 12-Å-wide strained [111]-oriented In0.687Ga0.313As /In0.807Ga0.193As0.304P0.696 QWs of a semiconductor optical amplifier (SOA). The theoretical prediction of −112.24 kV/cm was in very good agreement, within the experimental error, with the value of the piezoelectric field extracted through the proposed procedure, which was also indirectly validated by comparing the experimental value of the 1s e-hh excitonic resonance Stark shift with the extracted one. Even though the implemented technique was specially designed to experimentally determine the piezoelectric field acting on each of the QWs of a multiple quantum well SOA, it can be applied to any p–i–n structure with electrodes and strained [111]-oriented zinc-blende QWs embedded in its intrinsic region. Remarkably, the method proposed here allows direct experimental determination of the piezoelectric field through an analytical expression, with which it is also possible to estimate, with high reliability, the precision of the result and how it is affected by the accuracy of each measuring instrument intervening in the procedure. [ABSTRACT FROM AUTHOR]

The preparation of high-quality GaAs crystals is the basis for the development of high-frequency microwave electronic devices and light-emitting devices. A molecular dynamics (MD) simulation of the directional solidification of GaAs was conducted. The anisotropic growth process and structural defects have been analyzed by radial distribution function, the largest standard cluster analysis, and visualization analysis. The results indicate that induced crystallization with different crystal orientations leads to different microstructural changes, which in turn cause the anisotropic growth of GaAs crystals. During the [100] crystal-oriented solidification, only sphalerite crystal structures were present in the system, while wurtzite structures were also formed in the [110] and [111] crystal orientation systems, and the [111] crystal orientation system is the more obvious. In addition, due to the dense packing structure of the (111) plane, numerous partial dislocations with a Burgers vector of 1/6< 112 > are formed in the GaAs crystal, and there is also a companion relationship between such dislocations and twins, which significantly reduces the crystallization effect. The study of the microstructure evolution of GaAs on the atomic scale provides a reference for the theory of crystal growth. [ABSTRACT FROM AUTHOR]

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Dachang ore field, located in the southwest margin of Jiangnan ancient land and the northeast side of Youjiang Basin, is an important non-ferrous metal ore producing area in China. Tongkeng deposit is a super-large tin polymetallic deposit with the largest scale, the most complex metallogenic elements and typical metallogenic characteristics in Dachang ore field, which is composed of up-per tin polymetallic ore body and deep zinc-copper ore body. Sphalerite was researched from different types of ore bodies (tin poly-metallic ore bodies, zinc-copper ore bodies) from copper pit deposits. Trace and rare earth element and H-O isotope analyses were conducted with the intention of further exploring the source of ore-forming materials and fluids in the area and deepening the under-standing of the genesis of the deposit. The results show that sphalerite in different types of ore bodies of Tongkeng deposit is character-ized by enrichment of Cu, Pb, Fe, Sb, In and poor Ce. The rare earth distribution patterns of sphalerite are mostly light rare earth en-riched V-shaped right-sloping curve, characterized by high LREE/HREE values and negative Eu and Ce anomalies. The H-O isotopic composition of sphalerite indicates that the ore-forming fluid is mainly magma, accompanied by the mixing of atmospheric precipitation. The above characteristics show that the ore-forming materials and ore-forming fluids of Tongkeng deposit mainly come front magma, and the genesis of the deposit belongs to magmatic hydrothermal filling metasomatism. [ABSTRACT FROM AUTHOR]

Porphyry copper deposits are important sources of copper and typically processed by flotation to produce copper concentrates. As mining areas become deeper, the amounts of impurities, such as sphalerite, can be increased in copper ores, so the appropriate depression of sphalerite floatability should be achieved to obtain saleable copper concentrates. In this study, the flotation behaviors of chalcopyrite and sphalerite in model samples mimicking copper ores with high Cu/Zn ratios (i.e., the ratio of chalcopyrite/sphalerite = 13:1) were investigated with zinc sulfate as a depressant for sphalerite. In addition, the effect of pyrite—a major gangue mineral in copper ores—on the depression of sphalerite floatability with zinc sulfate was examined. When sphalerite and chalcopyrite coexisted, the floatability of the former was effectively depressed by zinc sulfate (Zn recovery: <12%), whereas the presence of pyrite promoted the release of Cu2+ due to the galvanic interaction with chalcopyrite, which resulted in the elimination of the effectiveness of zinc sulfate in depressing sphalerite floatability (Zn recovery: >90%). Despite the presence of much higher amounts of chalcopyrite and pyrite than sphalerite, the application of nitrogen (N2) gas limiting the galvanic interaction between pyrite and chalcopyrite by reducing the dissolved oxygen (DO) concentration in the system effectively depressed the floatability of sphalerite (Zn recovery: <30%). [ABSTRACT FROM AUTHOR]

The sulfur isotope system is important in tracing a variety of geochemical processes. However, the availability of matrix‐matched reference materials for in situ sulfur isotope ratio measurement is limited. This study analysed four sulfide specimens to investigate their potential as reference materials for in situ sulfur isotope determination, including three natural sulfide minerals (sphalerite SPH‐1, chalcopyrite GC‐1 and galena NWU‐GN), and one resin preserved pyrite powder (RPPY). These four sulfides were analysed independently in four laboratories using both bulk and microbeam analysis techniques, all of which gave equivalent results within uncertainty with comparable accuracy and precision. The sulfur isotopes of these four sulfides are homogeneous based on a large number of isotope determinations by solution nebulisation multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS) and laser ablation (LA) MC‐ICP‐MS. The mean δ34S values for SPH‐1, RPPY, GC‐1 and NWU‐GN determined by gas source isotope ratio mass spectrometry (GS‐IRMS) and solution nebulisation MC‐ICP‐MS are −7.13 ± 0.41‰ (2s), 3.66 ± 0.24‰ (2s), −0.65 ± 0.28‰ (2s), 28.21 ± 0.17‰ (2s) relative to the Vienna‐Canyon Diablo troilite (V‐CDT) reference value, respectively, and which are proposed as potential preferred values. Over 400 spot analyses performed on randomly selected fragments of each sulfide by LA‐MC‐ICP‐MS yielded highly consistent δ34S values with the preferred values. Thus, SPH‐1, GC‐1, NWU‐GN and RPPY are considered a set of candidate matrix‐matched sulfide reference materials for in situ sulfur isotope determination. [ABSTRACT FROM AUTHOR]

This study examined the micro‐homogeneity of zinc isotope composition of the NIST SRM 683 and NBS 123 reference materials using femtosecond laser ablation multi‐collector inductively coupled plasma‐mass spectrometry (fsLA‐MC‐ICP‐MS). NIST SRM 683 and NBS 123 are homogeneous in Zn isotope composition based on numerous measurements performed on twenty chips and four mounts of sphalerite using solution nebulisation (SN)‐MC‐ICP‐MS and fsLA‐MC‐ICP‐MS. The mean δ66ZnJMC‐Lyon values of NIST SRM 683 and NBS 123 determined by SN‐MC‐ICP‐MS were 0.11 ± 0.02‰ (2 standard deviation (2s), n = 100) and 0.16 ± 0.02‰ (2s, n = 62), respectively. The mean δ66ZnJMC‐Lyon values determined by fsLA‐MC‐ICP‐MS analyses for NIST SRM 683 and NBS 123 were 0.12 ± 0.05‰ (2s, n = 200) and 0.16 ± 0.05‰ (2s, n = 212), consistent with the bulk isotope compositions within uncertainty. The in situ measurement precision for NIST SRM 683 and NBS 123 was better than 0.06‰ (2s), suggesting NIST SRM 683 and NBS 123 are suitable to serve as microanalytical reference materials for Zn isotope measurement. Zinc isotopic compositions of Zn‐rich materials were also determined using fsLA‐MC‐ICP‐MS under wet/dry plasma conditions. Their δ66ZnJMC‐Lyon values were in agreement with those obtained by SN‐MC‐ICP‐MS analysis, suggesting that fsLA‐MC‐ICP‐MS is suitable to measure Zn isotopic ratios in Zn‐rich materials. Thus, this method could potentially analyse spatially resolved Zn isotope compositions at the mineral or even sub‐mineral scale, such as to address the process of ore formation or Zn redistribution in near‐surface environments. [ABSTRACT FROM AUTHOR]

In this study, the flotation behaviors of gold and gold-associated sulfide minerals (pyrite and sphalerite) in a polymetallic sulfide gold ore were investigated using flotation kinetics parameters. It was found that high gold recovery (>90%) can be achieved by the selective flotation of pyrite and sphalerite. However, the sphalerite flotation results showed that sphalerite could not be separated from pyrite with a high selectivity (selectivity index∼1), because of insufficient depression of pyrite (with high alkaline medium and/or using a depressant). Even if more selective separation was achieved from the pyrite flotation (selectivity index∼5), 40% of sphalerite in the ore was transferred into the pyrite concentrate. In addition, the results of the collectorless tests indicated that more than 80% of the gold can be recovered, and higher selectivity indexes (up to 10) are achievable. Analysis of the particle size distribution of the collectorless flotation concentrate showed that the amount of −40 μm in the concentrate was 90%. In conclusion, a gold concentrate containing low sulfur (10.8%) with a gold recovery of greater than 95% is achievable from a two-stage flow sheet (collectorless flotation as the rougher stage and pyrite flotation as the scavenger stage). [ABSTRACT FROM AUTHOR]

In the present work the effect of alkaline sulfide leaching (ASL) on the extraction of copper and zinc from low-grade copper concentrate containing chalcopyrite, tennantite, sphalerite, and pyrite during batch and continuous bioleaching experiments was studied. It was demonstrated that ASL and further bioleaching may be a promising approach for treatment of copper–zinc concentrates containing tennantite as this approach allows increasing copper extraction degree in comparison to one-stage bioleaching by 1.6–2.3 times. Thus, ASL was shown to be effective for pretreatment of tennantite containing concentrates to improve bioleaching for copper extraction. At the same time, ASL led to decrease in zinc extraction by 1.4–1.5 times. Therefore, the development of combined hydrometallurgical processes including ASL and bioleaching for effective metal leaching requires further studies to avoid negative effect on zinc extraction. [ABSTRACT FROM AUTHOR]