Search

Currently, most of the methods for mineral materials analysis generate secondary pollution, which is detrimental to human health. For instance, traditional methods for sphalerite analysis in the zinc (Zn) smelting industry including chemical titration, atomic absorption spectrometry, and inductively coupled atomic emission spectroscopy. Colored indicators and toxic heavy metals are used in the analytical processes, causing severe pollution. For some methods, liquid is transformed into gaseous plasma, which is more dangerous to human health. Due to large quantities of sphalerite being used, secondary pollution cannot be ignored. This study proposes a green analysis method for the detection of sphalerite based on colorimetry, which does not generate secondary pollution. The results show that the strong substitution ability of iron (Fe) for Zn contributes to their inverse correlation in contents. The lattice parameters decrease with the increasing Fe content, resulting in a darker coloration. Here, key colorimetry parameters of L*, a*, and b* show clear linear correlations with the Zn and Fe contents. Compared with traditional approaches, this new method is environmental friendly with high sensitivity and accuracy. The relative error and relative standard deviation were less than 10% and 5%, respectively. This study provides a significant reference for nonpollution determination of other mineral materials. [ABSTRACT FROM AUTHOR]

Palladium nanoparticles were produced by a chemical reagent-free and versatile method called spark ablation with control over particle size and density. These nanoparticles were used as catalytic seed particles for gallium phosphide nanowire growth by metalorganic vapour-phase epitaxy. Controlled growth of GaP nanowires using significantly small Pd nanoparticles between 10 and 40 nm diameter was achieved by varying several growth parameters. Low V/III ratios below 2.0 promote higher Ga incorporation into the Pd nanoparticles. Moderate growth temperatures under 600 °C avoid kinking and undesirable GaP surface growth. In addition, a second batch of palladium nanoparticles of concentration up to 1000 particles μ m−2 was deposited onto the GaP nanowires. Subsequently, three-dimensional nanostructures evolved, with branches growing along the surface of the GaP nanowires. The GaP nanowires revealed a zinc blende structure with multiple twinning and a PdGa phase at the tip of the nanowires and branches. [ABSTRACT FROM AUTHOR]

The continuous exploitation of zinc blende resources leading to primary resources may not be sufficient for future requirements. The abundant low-grade lead–zinc oxysulphide ore will become a crucial source of zinc metal. Thus, methods for utilising low-grade lead–zinc ore resources must be urgently developed; this can contribute to achieving considerable economic value. By studying the mineral technology and thermodynamics of low-grade lead–zinc oxysulphide ore, a Box–Behnken design model of response surface methodology was created to explore the impact of various factors, such as reduction time, temperature, and carbon mass ratio. The outcomes of the study indicated that the aforementioned factors have a significant impact on the zinc volatilisation rate, and it reaches 99.01% under the optimum conditions of 1174 °C, 86 min, and 12% carbon mass ratio. In addition, compared with the carbothermal reduction in air, the carbon mass ratio requirement is reduced by 10–20% in the inert atmosphere. The volatilisation mechanism of zinc, particularly the distribution and migration behaviour, was studied using X-ray diffraction and scanning electron microscopy–energy dispersive X-ray spectroscopy. The results showed that in the high-temperature section of the lead–zinc ore treatment, zinc sulphide and zinc oxide are transformed via the synergistic reduction involving carbon and calcium to zinc, and the presence of iron and calcium in the form of sulphides leads to a decrease in sulphur dioxide formation. This study explores the efficient and green development and utilization of low-grade lead–zinc oxysulphide ore by pyrometallurgical method to provide theoretical support for its large-scale industrial treatment. [ABSTRACT FROM AUTHOR]

A series of twin-phase Mn x Cd 1-x S solid solutions with zinc blende (ZB) and wurtzite (WZ) structures were prepared by an alkaline hydrothermal method in this work. When using 0.35 M Na 2 SO 3 /0.25 M Na 2 S solution as a sacrificial agent under visible light (λ ≥ 420 nm), the H 2 production activity of T-Mn 0.5 Cd 0.5 S is 33.4 mmol h−1 g−1, significantly higher than that of ZB-Mn 0.5 Cd 0.5 S (15.4 mmol h−1 g−1) or WZ-Mn 0.5 Cd 0.5 S (18.2 mmol h−1 g−1). The photocatalytic activity of T-Mn 0.5 Cd 0.5 S is further enhanced by introducing Ni 12 P 5 as a cocatalyst, in which the H 2 evolution rate of 0.2% Ni 12 P 5 /T-Mn 0.5 Cd 0.5 S can reach 96.5 mmol h−1 g−1, 2.89 and 1.77 times than that of pure T-Mn 0.5 Cd 0.5 S and 0.5% Pt/T-Mn 0.5 Cd 0.5 S (54.6 mmol h−1 g−1), respectively. The crystalline phase, microstructure, elemental composition, optical and optoelectronic properties of the samples were characterized by XRD, SEM, TEM, HRTEM, XPS, UV–vis, PL and electrochemical workstation. The results show that the formation of a homojunction with interlaced energy band inhibits carrier recombination in the bulk phase of T-Mn 0.5 Cd 0.5 S. In addition, Ni 12 P 5 can substitute for the noble metal as a cocatalyst to reduce the overpotential and improve the separation rate of electrons and holes to enhance H 2 evolution. This work provides reference for building homojunction photocatalysts and loading inexpensive transition metal phosphides instead of noble metals. [Display omitted] • The twinned Mn x Cd 1-x S of zinc blende (ZB) and wurtzite (WZ) was prepared in an alkaline hydrothermal method. • The introduction of Ni 12 P 5 by in situ hydrothermal method further enhanced photocatalytic H 2 evolution activity. • The efficient Ni 12 P 5 /T-Mn 0.5 Cd 0.5 S photocatalyst is a beneficial effect of twinned structure and cocatalyst Ni 12 P 5. [ABSTRACT FROM AUTHOR]

The Pusangguo deposit (1.42 Mt @ 1.42% Cu, 0.14 Mt @ 1.82% Zn, 0.08 Mt @ 1.01% Pb, and 285.8 t Co @ 140 g/t Co) is the first Co-rich Cu-Zn-Pb skarn deposit discovered in the Gangdese metallogenic belt. However, the trace and minor element geochemistry of the sulfides in this deposit has not been studied, limiting further understanding of elements' occurrence and mineralization. Here, we identified four ore stages, and two types of sphalerites (SpI and SpII) and pyrites (PyI and PyII), in this deposit. In this study, LA-ICP-MS in-situ trace element analyses were conducted on sphalerite and pyrite, to obtain their chemical compositions, elemental substitution mechanisms, and mineralization physicochemical conditions. The results indicate that two types of sphalerites are generally more enriched with Co than pyrite. SpI has higher concentrations of Co, Cr, Cu, Ag, and As compared to SpII. Both types of sphalerite have very low contents of Sn, Ge, and Ga. PyII has higher contents of most trace elements, such as Co, Ni, Mn, Zn, Cu, As, Sn, Se, Pb, Ag, and Bi, compared to PyI. Both types of pyrite are poor in Mn, Ga, Ge, and Cd, but enriched in As, Co, and Ni. The Mn, Fe, Co, and Cd in sphalerite, and Co, Ni, and Mn in pyrite are generally lattice-bound, while Cu, As, Ag, and Sb are usually present in both micro-inclusions and coupled substitution. Significant elemental correlations in sphalerite indicate the possible substitution mechanisms 2Fe2+ + Ga2+ ↔ 3Zn2+, 2Fe2+ + Ge4+ ↔ 4Zn2+, and (Sb3+, Sn3+) + (Cu+, Ag+) ↔ 2Zn2+. The correlation trends between trace elements in pyrite suggest the coupled substitution mechanisms of (Tl+ + Cu+ + Ag+) + (As3+ + Sb3+) ↔ 2Zn2+ and As3+ + Cu+ ↔ 2Zn2+. The mineralization temperature at Pusangguo, as determined by the GGIMFis sphalerite geothermometer, is 237–345 °C (avg. 307 °C), consistent with the high Zn/Cd ratio (avg. 203), low Ga/In (avg. 0.06), and high In/Ge (avg. 15.9) in sphalerite, and high Co/Ni ratio (avg. 24) in pyrite. These results indicate that the ore-forming fluid was high-temperature, with a low sulfur fugacity (fS2) (10−13.4 to 10−8.3) and low oxygen fugacity (fO2). The high temperature, and low sulfur fugacity and oxygen fugacity of the ore-forming fluid, and the fluid-mixing process, jointly controlled the sulfide precipitation, which caused the formation of the Pusangguo deposit. [ABSTRACT FROM AUTHOR]

Zn ions are widely reported to possess a depression effect on sphalerite in flotation. The effective adsorption of Zn ions on a sphalerite surface is critical to realize the inhibition effect. At the same time, zinc ions are easily hydrated in a slurry solution. Therefore, based on the first principle DFT calculation, the molecular mechanism of Zn ion adsorption on the surface of Sphalerite is further studied from the perspective of hydration. [Zn(H2O)5]2+, [Zn(OH)(H2O)3]+ and [Zn(OH)2(H2O)2] are found to be the effective components of Zn ions adsorbed on a sphalerite (110) surface in the neutral condition. Furthermore, the adsorption mechanism of [Zn(H2O)5]2+ on a sphalerite (110) surface is mainly via the hybridization of Zn 3d orbital in the structure of [Zn(H2O)5]2+ with surface S 3p orbitals. Additionally, the adsorption mechanism of [Zn(OH)(H2O)3]+ and [Zn(OH)2(H2O)2] on a sphalerite (110) surface is primarily ascribed to the hybridization of surface Zn 3d orbital with O atom of hydroxyl ligand 2p orbitals. In addition, the H 1s orbits in the water molecules have a weaker interaction with the sphalerite surface S 3p orbits. This work sheds new light on the adsorption and inhibition mechanism of zinc ions on a sphalerite surface in a neutral aqueous solution. [ABSTRACT FROM AUTHOR]

A new reference material, STDGL3, for the calibration of in situ analyses of sulfide minerals by LA‐ICP‐MS has been developed and characterised. It represents a lithium‐borate‐based glass containing a mixture of Zn‐ and Fe‐sulfide concentrates doped with several chalcophile elements as well as Zr, Gd, Hf and Ta required for assessing common interferences on Ag, Au and Pt. STDGL3 has a wider range of elements and a better homogeneity compared with existing reference materials for LA‐ICP‐MS analysis of sulfides. Compositional variations for most elements are below 3% RSD, below 5% RSD for Ag, Au and Pt, and below 7% RSD for Se, when performing spot analyses with a 50 μm beam size. Its preparation recipe is reproducible allowing for multiple batches to be made. Use of STDGL3 significantly improves accuracy of sulfide mineral analysis by LA‐ICP‐MS when compared with use of other available reference materials. Performance of STDGL3 was evaluated using several different laser systems. No significant change was observed between 193 nm ArF excimer lasers with 5 and 20 ns pulse widths, but use of 213 and 248 nm lasers displays more systematic differences, especially when analysing galena. Correction coefficients are needed for some elements (Zn and Cd in particular) when analysing sulfide minerals using STDGL3 as a calibration reference material. [ABSTRACT FROM AUTHOR]

The physical and chemical features of the SiGe1 − xSnx ternary alloy structured in cubic phase are investigated. Three distinct approaches (PBE-GGA), (PW-LDA), and (PW-LDA) are used to compute the structural characteristics such as the lattice constants a, the bulk modulus B and its first pressure derivative B'. Alongside the PBE-GGA method, we utilized the recently introduced (TB-mBJ) approach incorporating spin–orbit coupling (SO) to analyze the electronic properties (band structure as well as density of states (DOS)) for the investigated materials. Additionally, for providing a more precise understanding of the alloys' electrical characteristics. By varying the tin composition from 0 to 1 by 0.25 steps, the optical characteristics of the studied materials are also evaluated with TB-mBJ + SO. The ternary alloys SiGe0.75Sn0.25, SiGe0.5Sn0.5, and SiGe0.25Sn0.75 are direct bandgap semiconductors while the binary compounds SiGe and SiSn are indirect bandgap semiconductors. The main Tomas Charpin's model is used to compute the elastic characteristics of ternary alloys with their binary constituents. Except for the binary compounds SiGe and SiSn, the other ternary alloy results are scarce. [ABSTRACT FROM AUTHOR]

It is known that doping zinc sulfide (ZnS) nanoparticles with Mn or Cu ions significantly affects their luminescent properties. Herein, we investigated how dopant atoms are incorporated into the structure of ZnS using X-ray diffraction and multi-edge X-ray absorption spectroscopy. The observed broadening of the X-ray diffraction patterns indicates an average crystallite size of about 6 nm. By analyzing the Zn, Mn, and Cu K-edge extended X-ray absorption fine structure (EXAFS) spectra using the reverse Monte Carlo method, we were able to determine the relaxations of the local environments around the dopants. Our findings suggested that upon the substitution of Zn by Mn or Cu ions, there is a shortening of the Cu–S bonds by 0.08 Å, whereas the Mn–S bonds exhibited lengthening by 0.07 Å. These experimental results were further confirmed by first-principles density functional theory calculations, which explained the increase in the Mn–S bond lengths due to the high-spin state of Mn 2 + ions. [ABSTRACT FROM AUTHOR]

ZnS nanomaterials were effectively synthesized by the chemical co-precipitation method by using Zinc Acetate (Zn (CH3COO)2·2H2O), sodium sulfide (Na2S) and Poly Vinyl Pyrollidine (PVP) as precursor materials. The reactions were carried out at ambient temperature. The X-ray diffraction (XRD) studies confirmed the cubic zinc blende shape of ZnS. Surface morphology of the prepared material was analyzed by scanning electron microscopic (SEM) and transmission electron microscopic (TEM) techniques. The average particle size of the ZnS is found to be around 2 to 3 nm. Optical studies were carried out to calculate band gap energy by using UV-visible spectroscopy. The band gap energy of prepared ZnS nanoparticles is found to be as 3.7 eV. [ABSTRACT FROM AUTHOR]

This study is the first to report the high performance of calcined natural sphalerite as a heterogeneous catalyst (Catalyst) in the piezo- and photocatalytic degradation of pharmaceuticals (bezafibrate and ceftriaxone) using high-frequency ultrasound (US, 1.7 MHz) and ultraviolet-light-emitting diodes (LED, 365 nm). The kinetic comparison showed that piezo-photocatalysis (LED + US + Catalyst) was more efficient than photocatalysis (LED + Catalyst) for degrading both contaminants in deionized water as well as in surface river water at natural pH (7.9). Despite reducing degradation rates (~1.7 times) in river water due to the scavenging effect of its constituents, ceftriaxone and bezafibrate were degraded by 77% and 48% after 1 h of exposure, respectively. Adding H2O2 increased the corresponding pseudo-first-order rate constants, and the complete degradation of ceftriaxone was achieved. However, the contribution of ultrasound at a given intensity was hidden, which resulted in a similar performance of piezo-photocatalysis and photocatalysis for treating river water. No pronounced synergy between the piezo- and photocatalytic processes was observed in the experimental conditions used. Nevertheless, the H2O2-assisted piezo-photocatalysis using high-frequency US, LED, and natural catalysts can be considered a novel and effective strategy for eliminating pharmaceuticals from real water without pH adjustment. [ABSTRACT FROM AUTHOR]

A late-deposited colloform banded sphalerite from Pcheloyad and Sporno deposits in samples from the Earth and Man National Museum was studied. Its composition is very close to the theoretical one for sphalerite. Iron, gallium, cadmium and indium are established as trace elements in concentrations lower than those in earlier deposited sphalerite generations. The presence of wurtzite was proved by X-ray powder diffraction. A similar low-temperature colloform banded sphalerite of the Schalenblende type has so far not been described in the lead-zinc Zvezdel-Pcheloyad ore field. [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.)

CdZnTe (CZT) is an II–VI compound semiconductor with a zinc blende structure and has a wide range of applications in nuclear radiation detectors. As the device size becomes nanoscale, the displacement damage caused by high-energy proton irradiation in space environment has become one of the main factors affecting the electrical properties of components. In this paper, Monte Carlo software Geant4 is used to simulate the types and proportions of physical processes generated by different particles incident on CZT crystals, the proportion and depth distribution of NIEL of particles with different energy/angle. The results show that the type, energy and angle of incident particles will affect the proportion of energy deposition and the distribution of energy deposition with depth during irradiation. The physical effects are different under different irradiation conditions. The simulation results have reference value for studying the displacement damage law of CZT irradiated by particles under different conditions and the stability of CZT detector in radiation environment. [ABSTRACT FROM AUTHOR]

Synthetic organic germanium is hydroxyethyl germanium sesquioxides, i.e. Ge-132, spiro germanium, furan germanium derivatives, and other types of antiviral, anti-inflammatory, and anticancer organic germanium, which are compounds with a wide range of pharmacological effects, but are easy to cause calcium deficiency when taken in excess; natural organic germanium is extracted from natural plants or consumed directly without any toxic side effects on the human body; bio-organic germanium is germanium compounds implanted in living organisms such as yeast, bacteria macrofungi, and vegetables. However, to clarify the definition of organic germanium, we divide organic germanium into three main categories: synthetic organic germanium; natural organic germanium; and bioorganic germanium (Narokha et al., [34]). In this part, we proposed many content about We Ge-132 and spirogermanium, because these two types of organic germanium are the most studied types of organic germanium and also the most promising organic germanium for applications, while other organic germanium are almost uncommon with no precise conclusions (Prónai & Arimori, [35]). The main criticism of Filella ([11]) against us is that we confuse the types of organic germanium and the lack of a clear definition and discussion of organic germanium. [Extracted from the article]

Methanol (MeOH) is largely used in industry but it is poisonous when ingested. A new microconductometric transducer is proposed for the detection of methanol vapor. The sensitive part of this methanol microsensor is prepared by the encapsulation of zinc sulfide (ZnS) nanoparticles (NPs) in chitosan. ZnS NPs were prepared through an aqueous colloidal route, Artemisia Herba Alba (AHA) plant extract being used as a capping agent. ZnS AHA NPs presents an average nanocrystal size of 3.93 nm with a cubic zinc blende structure. The ZnS AHA NPs were well dispersed in an electrodeposited chitosan film on interdigitated electrodes, for conductometric measurements. The ethanol, methanol and acetone gas-sensing responses of the films were measured at room temperature. The sensors' response time (tRec) for methanol is from 11 to 25 s from lower to higher concentrations. The limit of detection for methanol is 1400 ppm in the gas phase. The methanol sensor presents 3.8 times lower sensitivity for ethanol and 30 times lower sensitivity for acetone. The shelf life of the methanol sensor is one month. [ABSTRACT FROM AUTHOR]

The fundamental properties of dislocations in diamond-structured Si and sphalerite-structured GaAs, InP and CdTe are investigated based on lattice theory of dislocation, hoping to provide some theoretical references in improving the properties of related materials. The influences of the surface effect(SE) and elastic strain energy on the structure and mechanical property of dislocation are discussed systematically. After considering the SE, the core width of dislocation becomes wider due to the elastic interaction between atoms becomes stronger. Compared to glide partial dislocation, the correction of SE to shuffle dislocation is more obvious. Both the SE and the elastic strain energy affect the energy barrier and Peierls stress of dislocation. The influence of SE on energy barrier and Peierls stress mainly results from the misfit energy and elastic strain energy become lower when the core of dislocation becomes wider. While the influence of elastic strain energy on energy barrier and Peierls stress mainly results from the cancellation between misfit energy and elastic strain energy for they possess comparable amplitudes but opposite phases. In addition, it is deduced that for the studied crystals, the shuffle dislocations control the deformation at medium and low temperatures, while glide partial dislocations are responsible for high temperature plasticity. [ABSTRACT FROM AUTHOR]

The superlarge Huaaobaote Ag–Pb–Zn deposit is located on the western slope of the southern Great Xing'an Range (SGXR). The deposit includes four ore blocks, namely, ore blocks I, II, III, and V. Except for the no. I orebody of ore block I, which is hosted in the contact zone between the Carboniferous serpentinized harzburgite and the Permian siltstone, the other orebodies all occur as veins controlled by faults. The mineralization process at the deposit can be divided into four stages: cassiterite–arsenopyrite–pyrite–quartz stage (stage I), cassiterite–chalcopyrite–pyrite–freibergite–arsenopyrite–pyrrhotite–quartz stage (stage II), sphalerite–galena–jamesonite–stibnite–freibergite–silver mineral–quartz–calcite–chlorite stage (stage III), and argentite–pyrargyrite–pyrite–quartz–calcite (stage IV). Cassiterite U–Pb dating of the Huaaobaote deposit yielded ages of 136.3–134.3 Ma, indicating that the deposit formed in the Early Cretaceous period. Two types of fluid inclusions (FIs), including liquid-rich and gas-rich FIs, have been distinguished in the quartz vein and sphalerite. The homogenization temperature during the four stages gradually decreases, with temperatures of 302–340 °C for stage I, 267–304 °C for stage II, 186–273 °C for stage III, and 166–199 °C for stage IV, respectively. The salinity (wt% NaCl eqv.) at stages I, II, III, and IV is 3.7–6.6, 0.2–4.5, 0.2–5.0, and 0.4–1.6, respectively, indicating that the ore-forming fluid is characterized by low salinity. The δ18Owater and δD values of the ore-forming fluid range from −11.9‰ to 7.9‰ and −168‰ to −76‰, respectively, indicating that the ore-forming fluid was dominantly derived from a mixture of magmatic and meteoric water. The calculated δ34SH2S values range from −3.6‰ to 1.2‰, indicating that the sulfur mainly came from granitic magma. The 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb ratios of sulfides are in the ranges of 18.195–18.317, 15.509–15.667, and 37.965–38.475, respectively, implying that the ore-forming material was mainly derived from felsic magma that may be formed by the partial melting of orogenic materials. Fluid mixing, cooling, and immiscibility were the three primary mechanisms for mineral precipitation in the Huaaobaote deposit. [ABSTRACT FROM AUTHOR]

The Ildeus mafic–ultramafic complex represents plutonic roots of a Triassic magmatic arc tectonically emplaced into the thickened uppermost crust beneath the Mesozoic Stanovoy collided margin. The mafic–ultramafic complex cumulates host Ni-Co-Cu-Pt-Ag-Au sulfide-native metal-alloy mineralization produced through magmatic differentiation of subduction-related primary mafic melt. This melt was sourced in the metal-rich sub-arc mantle wedge hybridized by reduced high-temperature H-S-Cl fluids and slab/sediment-derived siliceous melts carrying significant amounts of Pt, W, Au, Ag, Cu and Zn. Plutonic rocks experienced a pervasive later-stage metasomatic upgrade of the primary sulfide–native metal–alloy assemblage in the presence of oxidized hydrothermal fluid enriched in sulfate and chlorine. The new metasomatic assemblage formed in a shallow epithermal environment in the collided crust includes native gold, Ag-Au, Cu-Ag and Cu-Ag-Au alloys, heazlewoodite, digenite, chalcocite, cassiterite, galena, sphalerite, acanthite, composite Cu-Zn-Pb-Fe sulfides, Sb-As-Se sulfosalts and Pb-Ag tellurides. A two-stage model for magmatic–hydrothermal transport of some siderophile (W, Pt, Au) and chalcophile (Cu, Zn, Ag) metals in subduction–collision environments is proposed. [ABSTRACT FROM AUTHOR]

The Huoshaoyun zinc–lead deposit, a giant non-sulfide deposit in Xinjiang, is one of the most significant discoveries of zinc–lead deposit in China and globally in recent years. The deposit is dominated by zinc–lead non-sulfides, with minor occurrences of sulfides such as sphalerite, galena, and pyrite. The non-sulfide minerals include smithsonite, cerussite, anglesite, and Fe-oxide. This study focuses on the mineralogical characteristics of sulfide and non-sulfide ores, as well as the trace element characteristics of sphalerite, smithsonite, and Fe-oxide. Mineralogical analysis reveals that smithsonite is derived from the oxidation of primary sulfide minerals and can be classified into three types that are generated during different stages of supergene oxidation. The three types of smithsonite are formed through replacing the sphalerite and host limestone, as well as directly precipitating in the fissures and vugs. Trace element analysis of sphalerite indicates that it is rich in Cd, Tl, and Ge, but poor in Fe and Mn. The ore-forming temperature, calculated using the GGIMFis geothermometer, is mostly within the range of 100~150 °C. Moreover, the trace element characteristics, ore-forming temperature, and S and Pb isotope compositions of the sulfide ores of the Huoshaoyun deposit are similar to those of the Jinding and Duocaima MVT lead–zinc deposits, which are also located in the Eastern Tethyan zinc–lead belt. This suggests that the sulfide orebody in the Huoshaoyun Zn-Pb deposit could also be the MVT deposit. Study of the trace element of the non-sulfide minerals shows that the Mn and Cd are relatively enriched in smithsonite, while Ga, Ge, and Pb are enriched in Fe-oxide. This can be attributed to distinct geochemical properties of the trace elements in the non-sulfide minerals of the Huoshaoyun deposit and is consistent with those of the other oxidized MVT deposits, thus indicating the supergene oxidation process of this deposit. [ABSTRACT FROM AUTHOR]

The newly discovered unusual epithermal manganese mineralization was found at the 18th level of the Rozália mine in the Štiavnica stratovolcano and it is hosted by a NE-SW oriented fault dipping 55° to SE. Based on its structural setting and cross-cut relationship to a pre-caldera vein it belongs to a large system of post-caldera veins related to horst uplift in the central zone of the stratovolcano. The vein occurs in andesite and consists of two contrasting parts, including a part dominated by white coarse-grained calcite and Mn-rich part represented by abundant johannsenite, younger rhodonite and Mn-carbonates (rhodochrosite, Mn-calcite), in association with minor quartz, calcite, adularia, chlorite, and clinozoisite. Ore minerals are represented by sphalerite, galena, pyrite, chalcopyrite and rare inclusions of acanthite and can be found exclusively in the Mn-rich part of the vein. Johannsenite forms greenish-blue, greenish-brown or brown radial aggregates reaching up to 7 cm in size. Its average empirical formula is Ca0.96(Mn0.97Mg0.07Fe0.03)1.07(Si1.98Al0.02)2.00O6. Rhodonite shows a significant compositional variation of Ca and Mn contents, ranging from Ca0.48Mn4.56(Si5O15) to Ca1.58Mn3.41 (Si5O15) as well as minor amounts of Fe (up to 0.32 apfu), Mg (up to 0.14 apfu) and Al (0.06 apfu). Microthermometry of fluid inclusions hosted by johannsenite, rhodonite, sphalerite, calcite and Mn-calcite determined that the mineralization precipitated from fluids of low salinity (1.4 to 5.3 wt. % NaCl eq.) and moderate homogenization temperatures (187-318 °C), with a trend of simultaneous decrease in salinity and temperature, interpreted as mixing of fluids. Boiling of fluids was recorded in early calcite at temperatures from 275 to 279 °C, corresponding to pressure from 58 to 62 bars and paleodepth from 704 to 752 m. These values are similar to data from other post-caldera veins in the vicinity of the mine, as well as from other johannsenite-bearing epithermal deposits in the world. [ABSTRACT FROM AUTHOR]

Zinc Telluride ZnTe alloys and thin film have been fabricated and deposited on glass substrates by thermal evaporation method which may be a suitable window layer of zinc telluride with different annealing temperatures (373 and473) K for 60 minutes in vacuum. Deposited thin films with thickness 100 nm was characteristic by using X-ray diffraction XRD to know structures, Atomic Force Microscopy (AFM) to evaluate surface topology, morphology. It was found out that the vacuum annealing improves on thin ZnTe films structure and surface morphology. Structural analysis reveals that ZnTe films have zinc blende structure of cubic phase with (111) preferred reflection and grain size is enhanced from 8.6 to 16.7 nm with annealing. Optical properties where optical bandgap energy values slightly decreased (2.3-2.2) eV as the annealing temperatures. [ABSTRACT FROM AUTHOR]

Motivated by the wide-band-gap semiconductor properties of Zn-monochalcogenides (Zn-X; X:S, Se and Te), especially for their crucial industrial applications, we use a first-principles approach to investigate the B3 (zinc blende type) to B1 (rock salt type) structural transitions in this series of compounds as a function of pressure and temperature. Under static conditions (i.e., T = 0 K), the transition pressure is found to steadily drop from ZnS to ZnTe via intermediate ZnSe. Our calculations within quasi-harmonic approximation yield negative Clapeyron slopes of the B3–B1 phase boundaries for all the three compounds, where ZnTe has the highest negative slopes. We also present a completely new set of calculations for the thermoelasticity of Zn-X phases in the temperature range 0–1100 K. This article then addresses how the B3–B1 phase transitions can influence the mechanical as well as electronic properties of Zn-X. This phase transition always results in a softening of their elastic constant C12; however, C11 and C44 get stiffened. The same structural transition switches a semiconductor to conductor-type electronically favorable transition, as inferred from their high-pressure electronic structure. Among the three Zn-X compounds, ZnTe becomes the most metallic phase following the B3–B1 transition. Our findings offer a novel explanation for the complete loss of semiconductor property of these monochalcogenides at elevated pressures. [ABSTRACT FROM AUTHOR]

In this study, we have investigated the electronic and magnetic characteristics of doped and co-doped 3D SiC material using the main Korringa–Kohn–Rostoker (KKR) Green's function technique combined with coherent potential approximation (CPA). Two impurities are considered, namely, chromium (Cr) and manganese (Mn), are considered. Density of state (DOS) calculations show that pure SiC is an N-type semiconductor with a 1.3eV band-gap energy, while substituting Si with Cr/Mn leads to a metallic behavior. Electronic structure calculations also reveal no magnetic order in the pure compounds, consistent with experiments. By comparing the energies of the ferromagnetic and spin-glass states, we have showed that impurities also induce ferromagnetism compounds. Furthermore, for each concentration, the polarization is determined from the density of carriers at the Fermi level. Finally, the Curie temperature ( T C ) is calculated by the mean-field approach at concentrations near the percolation threshold. In both cases of Cr/Mn dopants, the value of T C is found to be greater than ambient temperature. [ABSTRACT FROM AUTHOR]

A new lime-Iree (lotation process was studied on a lead-zinc sullide ore containing 2. 22% lead, 2. 85% zinc and 105 g/t silver, which the main target minerals are galena and sphalerite. The results showed that under the condition ol the linness ol 一0. 074 mm occupying 66. 32% and adopting the lead-zinc sequence prelerential Ilotation process, lead concentrate containing 62. 10% Pb, 4. 79% Zn and 1 953. 36 g/t Ag was obtained by using zinc sullate + sodium pyrosullite + MZ, with the lead recovery ol 90.48% and siliver recovery ol 60. 12%; Zinc concentrate grading Zn 53. 15 %, Pb 1. 65% and Ag 262・ 74 g/t was also obtained by using sodium sullite+ copper sullate + MKX through closed-circui t test, with the zinc recovery of 87.42% and siliver recovery of 11. 67%. The high efficiency separation ol lead and zinc could be achieved without alkali, and the associated silver recovery can be signilicantly improved. [ABSTRACT FROM AUTHOR]

CdS thin films were grown on an FTO substrate at different temperatures, employing the low-cost hydrothermal method. All the fabricated CdS thin films were studied using XRD, Raman spectroscopy, SEM, PL spectroscopy, a UV–Vis spectrophotometer, photocurrent, Electrochemical Impedance Spectroscopy (EIS), and Mott–Schottky measurements. According to the XRD results, all the CdS thin films were formed in a cubic (zinc blende) structure with a favorable (111) orientation at various temperatures. The Scherrer equation was used to determine the crystal size of the CdS thin films, which varied from 25 to 40 nm. The SEM results indicated that the morphology of thin films seems to be dense, uniform, and tightly attached to the substrates. PL measurements showed the typical green and red emission peaks of CdS films at 520 nm and 705 nm, and these are attributable to free-carrier recombination and sulfur vacancies or cadmium vacancies, respectively. The optical absorption edge of the thin films was positioned between 500 and 517 nm which related to the CdS band gap. For the fabricated thin films, the estimated Eg was found to be between 2.50 and 2.39 eV. According to the photocurrent measurements, the CdS thin films grown were n-type semiconductors. As indicated by EIS, resistivity to charge transfer (RCT) decreased with temperature, reaching its lowest level at 250 °C. Flat band potential and donor density were found to fluctuate with temperature, from 0.39 to 0.76 V and 4.41 × 1018 to 15.86 × 1018 cm−3, respectively, according to Mott–Schottky measurements. Our results indicate that CdS thin films are promising candidates for optoelectronic applications. [ABSTRACT FROM AUTHOR]

The Nanmushu Zn–Pb deposit is a large-scale and representative deposit in the Mayuan ore field on the northern margin of the Yangtze Block. This study investigates the trace element geochemistry of sphalerite from this deposit using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The results show that the main trace elements in sphalerite include various trace elements, such as Mn, Fe, Cu, Ga, Ge, Ag, Cd, Pb, Co, Hg, Tl, In, Sn, and Sb. Among them, Ag, Ge, Cd, and Cu are valuable components that may be recovered during mineral processing or smelting techniques. The histograms, LA-ICP-MS time-resolved depth profiles, and linear scan profiles indicated that most trace elements occur in sphalerite as isomorphs, while partial Pb, Fe, and Ag occur as tiny mineral inclusions. The correlation diagrams of trace elements revealed that Fe2+, Mn2+, Pb2+, and Tl3+ can substitute Zn2+ in sphalerite through isomorphism. In sphalerite, Cd2+ and Hg2+ together or Mn2+, Pb2+, and Tl3+ together can replace Zn2+, i.e., ((3Mn, 3Pb, 2Tl)6+, 3(Cd, Hg)2+) ↔ 3Zn2+. Moreover, there is a mechanism of Ge4+ with Cu+ or Ga3+ with Cu+ replacing Zn2+ in the Nanmushu deposit, i.e., Ge4+ + 2Cu+ ↔ 3Zn2+ or 2Ga3+ + 2Cu+ ↔ 4Zn2+. Furthermore, the trace element compositions indicate that the Nanmushu Zn mineralization occurred under low-temperature conditions (<200 °C) and should be classified as a Mississippi Valley-type (MVT) deposit. This study provides new insights into the occurrence and substitution mechanisms of trace elements in sphalerite and the metallogenic constraints of the Nanmushu deposit. [ABSTRACT FROM AUTHOR]

The primary coexisting mineral with galena is sphalerite. Hence, it is critical to selectively separate galena from sphalerite by flotation. In this work, thiourea and related derivatives as potential flotation collectors for separating galena from sphalerite were investigated. Thiourea and its related derivatives were found to be effective selective collectors in batch flotation studies of a single mineral, with 1,1-diphenylthiourea (11DTA) emerging as the best choice. Galena has superior floatability compared to sphalerite in the presence of 11DTA, and the recovery difference between the two minerals at pH 8 (where the 11DTA concentration is 5 × 10−6 mol/L) is around 38%. This was revealed in batch flotation studies using artificial mixed minerals. Moreover, the findings from the measurements of adsorption amount, FTIR, zeta potential and XPS revealed that 11DTA has a strong adsorption on galena yet a relatively weak adsorption on sphalerite. Additionally, DFT calculations demonstrated that sphalerite exhibits stronger hydrophilicity than galena, and 11DTA possessed a better affinity for galena. [ABSTRACT FROM AUTHOR]

The Sinongduo mining region includes two types of mineralizations: the epithermal and the carbonate‐hosted Pb‐Zn‐Ag deposits. Despite being studied for many years, the ore formation process and genesis of the carbonate‐hosted Pb‐Zn‐Ag deposits remain poorly understood. The Pb‐Zn‐Ag ore bodies occur as veins and are hosted by limestone and dolostone of the Permian Xiala Formation. Three sulfide mineralization substages have been identified at the Sinongduo carbonate‐hosted deposit. Indium coupled with Cu, Co and Sn was incorporated into sphalerite as substitutions: 2Zn2+ ↔ Cu+ + In3+, (3n/2 + 1)Zn2+ ↔ Co2+ + nIn3+ or (2n + 1)Zn2+ ↔ Co2+ + n(Cu+ + In3+) (n > 1) and 4Zn2+ ↔ Sn2+ + 2In3+. Sphalerite and pyrite in the mineralization stage display δ34S values in a narrow range of +5.7‰ to +11.3‰, which are similar to those of Palaeocene igneous rocks, indicative of a magmatic source of sulfur. We present systematic carbon‐hydrogen‐oxygen isotope results that further support a magmatic source for the ore‐forming fluids that were influenced by meteoric water. Furthermore, the Pb isotope compositions of sulfide minerals in the Sinongduo carbonate‐hosted deposit overlap with the values of coeval Linzizong volcanic rocks and are similar to those of Indian Ocean sediments, indicating upper crustal sources of metals. We conclude that the Sinongduo carbonate‐hosted Pb‐Zn‐Ag deposit is a medium‐ to low‐temperature magmatic‐hydrothermal deposit related to Linzizong magmatism. [ABSTRACT FROM AUTHOR]

The Dulong deposit, located in the Laojunshan area of southeastern Yunnan, China, is an important polymetallic deposit due to its high reserves of tin, zinc, and indium. The occurrence state of indium is critical for understanding its supernormal enrichment mechanism. Previous studies investigated the occurrence state of indium (including the valence state) based on the indium content in sphalerite and the correlation between metal concentrations. However, more evidence is needed to better constrain indium occurrence at the micro-, nano-, or even atomic scale. In this study, EPMA-FIB-SEM-TEM and XPS techniques were employed to investigate the indium distribution characteristics and occurrence state in sphalerite from the Dulong Sn–Zn–In polymetallic deposit. The maximum concentration of indium in the indium-rich sphalerite samples is 0.37 %, and the results of the EPMA analysis showed a relatively homogeneous distribution of indium in sphalerite. The FIB-SEM-TEM results demonstrated that the lattice stripes of sphalerite were periodically and continuously distributed at the nanoscale, confirming that sphalerite in the deposit was an excellent single crystal structure, and the peak heights of the various characteristic peaks of indium in the EDX spectra were relatively close to each other, with no distinct peaks of high indium content. In addition, the XPS results indicate that the element valence state of indium in sphalerite is In3+, and it combines with S2− to form a bond. These results indicate that indium in sphalerite of the Dulong deposit is uniformly distributed at both the micro- and nanoscale, and there is no indium-independent mineral. In3+ enters the crystal lattice of sphalerite by replacing Zn2+ in the form of isomorphic substitution. [ABSTRACT FROM AUTHOR]

Sphalerite in Mississippi Valley–type (MVT) deposits hosts significant resources of both germanium and gallium. Here, we provide a survey on the distribution of Ge, Ga, and other minor and trace elements in sphalerite from MVT deposits in the Eastern Cordillera and sub-Andean regions of Peru, including the San Vicente deposit and the nearby Chilpes and Huacrash prospects, and the Shalipayco deposit. We present also a micro- and nano-scale textural characterization of Ge-rich sphalerite. In situ laser ablation-inductively coupled plasma-mass spectrometry analyses yielded Ge contents (inter-quartile range [IQR] = 164–36 ppm for the San Vicente district and IQR = 425–101 ppm for the Shalipayco deposit) that overlap with the range reported for sphalerite from other MVT deposits elsewhere. The highest Ge contents (IQR = 1207–375 ppm, up to 1861 ppm) were found in Fe-poor orange sphalerite deposited during a volumetrically minor second mineralization step in the San Vicente deposit located mainly in steep veins that crosscut the main first-step mineralization dominated by darker sphalerite. Reddish-brown sphalerite from Chilpes (IQR = 445–22 ppm, up to 1745 ppm) and brownish orange sphalerite from Huacrash (IQR = 650–34 ppm, up to 855 ppm) also yielded remarkably high Ge values. In Shalipayco, the highest Ge contents were analyzed in late Fe-poor yellow sphalerite (IQR = 375–267 ppm, up to 1119 ppm). The highest Ga contents were determined in reddish-brown sphalerite from the Chilpes prospect (IQR = 1156–0.26 ppm, up to 3943 ppm), although Ga contents are, in general, much lower than those of Ge in most analyzed sphalerite (IQR = 27–0.22 ppm in the San Vicente district and IQR = 2.8–0.081 ppm in the Shalipayco deposit). These figures place some of the analyzed sphalerite types among the Ge- and Ga-richest samples ever reported. Linkage of textural and compositional data points to light-colored, chiefly orange and yellow sphalerite generations crystallizing at lower temperatures and relatively late in the paragenetic sequences as those with the highest Ge contents. In contrast, the paragenetic control on Ga enrichment is unclear. Focused ion beam and high-resolution transmission electron microscopy (FIB-HRTEM) investigation combined with trace element content correlations reveal selective partitioning of Ge and Ga into sphalerite as structurally bound elements and their incorporation via substitution mostly coupled to monovalent cations triggering polytypism. [ABSTRACT FROM AUTHOR]

The Murcielago gold placer is located in the Lepaguare Valley, Olancho Department (Central Honduras). The placer mineralogy includes silicates (quartz, garnets, amphibole, Ca-pyroxene, micas, epidote, and tourmaline); calcite; and in the heavy fraction, zircon, ilmenite–rutile, magnetite, hematite, cassiterite, and cinnabar. Gold grains recovered from the Murcielago placer production plant are mainly flattened grains with a moderately to high elliptical shape. The composition of the gold grains varies continuously in the range Au 46 Ag 54 to Au 88 Ag 12 . Few of them are characterized by Au-rich rims of a few microns in size (Ag 3-1 atoms percent (at%)). Gold from the Canan lode deposit, a nearby hydrothermal Au mineralization area, has a composition (from Au 54 Ag 44 to Au 81 Ag 19 ) overlapping the composition of the Murcielago grains. Inclusions in the alluvial gold particles are arsenopyrite, pyrite, acanthite, sphalerite, and hematite. On the basis of the placer mineralogy and the gold grains analyses, possible gold source(s) include the Canan lode and skarn gold deposits in the area. We obtained new data on the Murcielago gold placer that will be the basis for an exploration of the potential sources of gold in the area. [ABSTRACT FROM AUTHOR]

Metal sulfides in waste rocks and tailings are susceptible to serious soil and water contamination due to the generation of acid mine drainage (AMD) during stockpiling. The hydrometallurgical process is one of the most essential heavy metal remediation technologies through harmless disposal and resource utilization of the waste sulfides. However, atmospheric hydrometallurgy of sulfides still faces great challenges due to low leaching efficiency and high cost. In this work, we proposed a cooperative leaching system (Fe2(SO4)3-O3) and investigated the oxidative dissolution process of sphalerite (ZnS). Under the optimal conditions, the extracted zinc reached 97.8%. Reactive oxygen species (ROS) (·OH, 1O2 and ·O2−) were identified in the radical quenching experiments. The dissolution of sphalerite did not show passivation due to the ozone’s capability to oxidize the sulfur in sphalerite to sulfate. In addition, stirring rate, O3 inlet concentration, and Fe2(SO4)3 concentration had a significant effect on the dissolution of sphalerite. Meanwhile, the apparent activation energy was 24.11 kJ/mol based on kinetic fitting, which indicated that the controlling step of the reaction was mainly a diffusion process. This work demonstrated the cooperative effect of sphalerite leaching in the O3-Fe2(SO4)3 system and provided a theoretical reference for efficient and atmospheric dissolution of sphalerite.

The physical and chemical properties of 210 nm thick InAsSbBi layers grown by molecular beam epitaxy at temperatures between 400 and 430 °C on (100) GaSb substrates are investigated using Rutherford backscattering, X-ray diffraction, transmission electron microscopy, Nomarski optical microscopy, and atomic force microscopy. The results indicate that the layers are nearly lattice matched, coherently strained, and contain dilute Bi mole fractions. Large surface droplets with diameters on the order of 1 μm and densities on the order of 106 cm−2 are observed when the InAsSbBi growth is performed with lean As overpressures around 1%. Surface droplets are not observed when the As overpressure is increased to 4%. Small crystalline droplets with diameters on the order of 70 nm and densities on the order of 1010 cm−2 are observed between the large droplets for InAsSbBi grown at 430 °C. Analysis of one of the small droplets indicates a misoriented zinc blende crystal structure composed primarily of In, Sb, and Bi, with a lattice constant of 6.543 ± 0.038 Å. Lateral modulation in the Bi mole fraction is observed in InAsSbBi layers grown at 400 °C. [ABSTRACT FROM AUTHOR]

Abstract The Foyemiaowan-Xindiantai cemetery, with more than 10,000 tombs, is located in north-west Gansu Province. The cemetery was active during the Sixteen-State Period of the Western Jin Dynasty (265–439 CE). As the largest ancient tomb group in the Dunhuang region, its cultural core is still mainly based on the cultural tradition of the Central Plains. Metal objects were texturally and chemically analyzed by optical microscopy (OM), scanning electron microscopy coupled with energy-dispersive spectrometry (SEM–EDS), and Raman spectroscopy. The analysis of 36 copper-based objects showed that the main alloying elements were tin and lead, while three objects were brass, with copper and zinc as the main elements. These three pieces of brass are the earliest brass objects found in Gansu Province. The brass contains numerous sulfide inclusions, indicating that the raw materials used to make these objects contained a large amount of residual sphalerite instead of being “pure” calamine. They were then hot forged directly from the original smelted brass, without having been remelted. Brass may have reached China during the Wei Jin Southern and Northern Dynasties (220–589 CE), but it was not widely used in China before the Ming Dynasty (1368–1644 CE). According to the statistics and relevant studies of brass unearthed before the Ming Dynasty in China, although the distribution of brass objects spans a considerable period, it concentrates in three areas from the early to the late stage, showing phased development characteristics. This includes accidental smelting in the Central Plains and Haidai areas, followed by external introduction in the northwest, and the emergence of local production in northeast China. Most brass objects contain lead and tin, which requires further exploration.

The Mutnovskoe deposit is one of the largest and most prospective ore deposits in South Kamchatka. The northern and southern flanks within the main veining zone Opredelyayushchaya, composed of low-sulfide (gold-silver) and sulfide-polymetallic (gold-silver-polymetallic) types of ores, respectively, are distinguished. The paper presents the results of the complex mineralogical and geochemical studies of the gold-silver-polymetallic ores of the southern flank of the deposit. Features of textures and structures, mineral, chemical compositions and genesis of the ores, as well forms of precious and base metals occurrences are shown. Typomorphic features of pyrite, sphalerite, galena, chalcopyrite, tennantite-tetrahedrite, Au, Ag, Pb and Bi tellurides, native gold, Bi, Se and Ag sulfosalts are characterized. The pyrite-sphalerite-quartz, sphalerite-galena-quartz, and chalcopyrite-ten- nantite-tetrahedrite mineral associations are distinguished. The temperatures and composition of ore-forming solutions are shown.

In the zinc-blende (zb) III-Ns (BN, GaN, AlN and InN), accurate knowledge of the phonon dispersions [ ω j q → ] and thermodynamical characteristics [e.g., Debye temperature Θ D T , specific heat C v (T )] are important not only from the academic standpoint but also for designing, evaluating/optimizing and integrating multifunctional devices into the highly demanding micro/nano-electronic circuits. In the quasi-harmonic approximation, our realistic rigid-ion-model calculations of the pressure dependent ω j q → , Θ D T and C v T for zb InN agreed very well with the experimental and first-principles data but are found different from a few simulations available in the literature. Like other cubic BN, GaN and AlN materials, we have perceived no negative thermal expansion (NTE) α T in the zb InN. Unlike many III–V compound semiconductors, no NTE in zb III-N materials at low temperatures is linked to the weak softening of γ TA X , L modes with strong directional partial covalent bonding. Variations of α T in the cubic BN, GaN, AlN and InN have exhibited features much like their C v T ′ s and revealed superior characteristics from the wurtzite III-N materials with intriguing industrial potentials for thermal management applications. [ABSTRACT FROM AUTHOR]

The aqueous metal‐sulfide batteries (AMSBs) have attracted research interest due to their high capacity, environmentally friendly qualities, and the accessibility of raw materials. However, the design strategies for metal‐sulfide cathode have rarely been reported. Here, the copper‐activated sphalerite in which Zn2+ is substituted by Cu2+ through ion exchange has been introduced for the first time as cathode for aqueous Cu/ZnS batteries. After sphalerite transformed to CuS, a two‐step conversion of CuS→Cu7S4→Cu2S storage mechanism has been proposed. At 0.7 A g−1 current density, the capacity can reach 532.4 mAh g−1 after 100 cycles. When cycled once at a current density of 35 mA g−1, the initial reversible capacity can reach 461 mAh g−1 under 1 A g−1. Furthermore, the assembled Zn//ZnS hybrid ion cell delivers an energy of up to 460 Wh kg−1, which is better than for many AMSBs. [ABSTRACT FROM AUTHOR]

Bioleaching has been regarded as a green alternative to chemical leaching in metal extraction processes. In this study, the bioleaching properties of indigenous acidophilic bacteria for various sulfide minerals were compared and evaluated in terms of pH reduction and metal leaching. The primary minerals in the samples were sphalerite (ZnS) (SP), galena (PbS) (GN1 and GN2), pyrite (FeS2) (PY), and chalcopyrite (CuFeS2) (CCP), and an indigenous acidophilic bacterium, Acidiphilium cryptum (99.56%), was applied for bioleaching experiments. The metal extraction in bioleaching differed according to the mineral content. The leached metal concentration of Zn was higher than that of Pb for the SP sample with a high ZnS content, whereas the concentration of Pb was higher than that of Zn for the GN1 and GN2 samples with a high PbS content. Meanwhile, the leaching rate of Zn was faster than that of Pb for all samples. Corrosion action was observed on the surface of bacterial residues in SP and GN1 samples. These results show that the bioleaching mechanism based on sulfide minerals proceeds through indirect biological oxidation, chemical oxidation, and direct bacterial oxidation. The results of this study can provide basic research data for process optimization when employing bioleaching to extract valuable metals. [ABSTRACT FROM AUTHOR]

Dolomite, CaMg(CO3)2 Dolomite is present as a rock-forming mineral at the North Vernon quarry and with one exception, does not form crystals - and even that occurrence is qualified. A 3.6-cm crystal of sphalerite, with epitactic chalcopyrite, on Geneva Dolomite, collected ca. 1979 from the Paul Frank (now Berry Materials) quarry at North Vernon. This 4.4-cm cluster of sphalerite crystals with tiny, 0.2-mm, chalcopyrite crystals and small, 1.7-mm, calcite crystals on Geneva Dolomite, was collected ca. 1979 from the Paul Frank (now Berry Materials) quarry. Chalcopyrite, CuFeS2 Copper-bearing minerals are uncommon in Indiana; however, tiny, 0.2-mm, crystals of chalcopyrite have been found on the surface of sphalerite crystals that occur in the Geneva Dolomite. [Extracted from the article]

Detailed, previously published literature on cactus quartz is somewhat scant and out of date (Cairncross and Dixon [4]; Cairncross [2]) or not published in English (Cairncross, Bahmann, and Knoper [3]). A doubly terminated amethyst perched horizontally on a matrix of pale amethyst; 10.8 cm. Ashley and Gail Diack specimen, Bruce Cairncross photo. A large cactus quartz crystal, flanked by two smaller crystals, and surrounded by a ring of smaller amethyst; 14.8 cm. Ashley and Gail Diack specimen, Bruce Cairncross photo. A cluster of dark amethyst cactus quartz, acquired in 1986 when the crystals first appeared on the market in South Africa; 9.2 cm. Bruce Cairncross specimen and photo. [Extracted from the article]

Based on the JK Drop Weight test and principle of selective crushing, a multicomponent complex ore with its component minerals, i.e., pyrrhotite, sphalerite, and quartz, was used to explore the impact crushing characteristics and relationship between the complex ore and its component minerals. Results show that the order of impact crushing resistance is quartz > pyrrhotite > ore > sphalerite. The particle-size-distribution characteristic curve of ore crushing products is always "sandwiched" between the curves of pyrrhotite, sphalerite, and quartz within the same feed-size range. When the particle size is −63 + 53, −45 + 37.5, −31.5 + 26.5, and −22.4 + 19 mm, the component mineral pyrrhotite has a negative effect on the impact crushing of ore, while the component mineral sphalerite has a positive effect. When the particle size is −16 + 13.2 mm, the component mineral pyrrhotite has a positive effect on the crushing effect of the ore, while the component mineral sphalerite has a negative effect. The component mineral quartz always has a negative effect on the impact crushing effect of ore in all the studied particle sizes. [ABSTRACT FROM AUTHOR]

Sphalerite is a common sulfide mineral, and xanthate is usually used as the collector of sphalerite flotation. In order to realize the simultaneous flotation of sphalerite- and zinc-containing oxide ores, in this paper, dodecylamine was used as the collector and sodium sulfide as the regulator to explore the flotation behavior of sphalerite in a sulfuration–amine system through single mineral flotation tests, and several analytical methods, including contact angle measurement, adsorption capacity test, FT-IR, and XPS, were employed to discuss the interaction mechanism of dodecylamine on the surface of sphalerite. The results confirm that dodecylamine had a strong collecting effect on sphalerite throughout almost the entire pH range, and the flotation recovery increased with the increase in pH, reaching 86.81% at pH 12. It was found that the effect of sodium sulfide on the floatability of sphalerite was relatively weak, and a weak activation effect, of about 2% improved recovery, was achieved. The results of the mechanism analysis further show that dodecylamine underwent both physical adsorption and chemical adsorption on the surface of sphalerite, and the physical adsorption was enhanced with the increase in pH. The above findings provide evidence for the simultaneous flotation of zinc-containing sulfide-oxide mixed minerals. [ABSTRACT FROM AUTHOR]

The paper reports the results of studies on critical metal mineralization genetically related to the late-stage intrusions of Salmi anorthosite-rapakivi granite batholith (SARGB) in the Riphean age. In, Bi, and Be mineralization in skarn-greisen deposits and occurrences at the SARGB endocontact, as well as REE and Nb-Ta mineralization in Li-F granites, understood as the late intrusive phases of the batholith, were studied. It is the first report on columbite-group minerals, as well as REE-Ta-Nb and REE mineralization in SARGB granites. Optical and scanning electron microscopy, EDS and LA ICP MS microanalysis, X-ray fluorescence spectrometry, Raman spectroscopy, and inductively coupled plasma mass spectrometry (ICP-MS) were used. The data obtained show that roquesite formation was mainly triggered by the decay of In-bearing solid sphalerite and chalcopyrite solutions. Zavaritskite, associated with unoxidized sulphides, was derived hypogenically and seldom occurs in ores. A helvine-group mineral association with zinc-enriched spinel (ZnO 22%–25%) seems to have been one of the factors preventing genthelvite formation. The Muzilampi, Hepaoja and Avtodor ore occurrences in Li-F granites display similar REE and Nb-Ta mineralization. They are associated with Y-fluorite and Li-siderophyllite, which contain exceptionally high Nb concentrations (0.25%–0.78%) in Muzilampi granites. Additionally, fluorite-1 is commonly overfilled (to >50%) with micron-sized synchisite and parisite inclusions. Columbite-tantalite-group minerals, present at all the occurrences studied, occur solely as ferricolumbites with a dominant Mn/(Mn + Fe) ratio of <0.2. Biotite and Li-siderophyllite, associated with columbite, have an extremely high iron index Fe/(Fe + Mg) > 0.9 approaching the maximum values (~1.0) in the most differentiated granites. [ABSTRACT FROM AUTHOR]

Temperature variations could potentially impact flotation performance, leading to operational and economic issues. Several historical and currently operating plants across Canada have reported seasonal metal losses as one of their major challenges. Improvements in flotation efficiency at cold temperatures are important for the sustainable development of the industry, especially in view of expanding mining operations to the north and the increasing impact of climate change-originated weather extremes on mining operations. To better understand the driving mechanisms of the seasonal metallurgical variation, the degree of vulnerability of froth flotation to fluctuations in temperature, and to develop recommendations addressing seasonally driven losses, a series of mono-mineral flotation tests were conducted. The observed variations in yield and recovery kinetics for different sulfide minerals follow a similar pattern: higher recovery and slower kinetics at lower temperatures, and lower recoveries and faster kinetics at higher temperature conditions. Following the results of the flotation tests, foam height and stability were investigated at different temperatures to explain the observed variations. A high correlation between changes in mono-mineral flotation behavior and foam properties with temperature was revealed. [ABSTRACT FROM AUTHOR]

Neutral mine drainage (NMD) at Force Crag mine in north-west England has a circumneutral pH and high levels of Zn contamination. A long-term geochemical and hydrological dataset from this site was analysed using a novel molar mass balance approach, which demonstrated that the water chemistry is dominated by species released by the oxidation of sulphides: sphalerite (Zn, Cd, Ni), galena (Pb, mostly removed by adsorption to ferrihydrite) and pyrite (Fe, mostly precipitates as ferrihydrite). The calculations show that the sphalerite:galena:pyrite oxidation ratio is ~1:2:1, but the mine water chemistry is dominated by Zn due to the removal of Pb and Fe by adsorption/precipitation. The acidity released by pyrite oxidation is neutralised by the dissolution of calcite and, to a lesser extent, chlorite. The presence of pyrite is responsible both for the release of acidity and the removal of some contaminant metals by adsorption on ferrihydrite. The concentrations of sulphate, Zn, Cd and Ni in the mine water decrease with increasing flow due to dilution; modest increases in metal flux with flow probably reflect increased oxidation due to greater amounts of oxygenated water flowing through the mine. In contrast, Al, Pb and Cu concentrations are positively correlated with flow due to the flushing of these metals adsorbed to ferrihydrite particles. The influence of temperature is relatively subtle; metal fluxes are a balance between abiotic oxidation (which increases at higher temperatures and flows) and bacterially mediated oxidation (which is depressed at high flow rates when temperatures decrease below 10 °C). These conclusions apply to NMD mine water throughout the UK and elsewhere in the world, including mines hosted in both limestone and silicate rocks. The molar mass balance approach, together with synchronous flow and geochemistry data, provides crucial information for effective mine-water-treatment system design by elucidating the critical roles of flow rate and temperature in determining contaminant concentrations and loads. [ABSTRACT FROM AUTHOR]