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1
Thériault, Robert D., Sarah-Jane Barnes i Mark J. Severson. "The influence of country-rock assimilation and silicate to sulfide ratios (R factor) on the genesis of the Dunka Road Cu – Ni – platinum-group element deposit, Duluth Complex, Minnesota". Canadian Journal of Earth Sciences 34, nr 4 (1.04.1997): 375–89. http://dx.doi.org/10.1139/e17-033.
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The Dunka Road deposit is one of several Cu – Ni – platinum-group element (PGE) sulfide occurrences found along the northwestern margin of the Duluth Complex, where the host troctolitic rocks are in contact with metasedimentary rocks of the Animikie Group. Magma contamination through assimilation of sulfidic argillaceous country rocks is generally recognized as having played a key role in the genesis of the mineralization. Three main types of disseminated sulfide mineralization have been identified within the Dunka Road deposit: (i) norite-hosted sulfides, (ii) troctolite-hosted sulfides, and (iii) PGE-rich sulfide horizons. The norite-hosted sulfides are found either adjacent to country-rock xenoliths or near the basal contact. The troctolite-hosted sulfides form the bulk of the deposit, and occur throughout the lower 250 m of the intrusion. The PGE-rich sulfide horizons are typically localized directly beneath ultramafic layers. The composition of the different types of sulfide occurrences is modelled using Cu/Pd ratios. It is shown that each type results from the interplay of two main parameters, namely the degree of magma contamination and the silicate magma to sulfide melt ratio (R factor). The norite-hosted sulfides formed at low R factors and high degrees of contamination, as expressed by their PGE-depleted nature, low Se/S ratios, and elevated content in pyrrhotite and arsenide minerals. The troctolite-hosted sulfides formed at moderate R factors and small degrees of contamination, as shown by their moderate PGE content and mantle-like Se/S ratios. Finally, the PGE-rich sulfide horizons are modelled using elevated R factors from an uncontaminated parental magma, which is substantiated by their elevated noble metal content and Se/S ratios, and low pyrrhotite to precious metal sulfide ratio.
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Agarbati, Alice, Laura Canonico, Francesca Comitini i Maurizio Ciani. "Reduction of Sulfur Compounds through Genetic Improvement of Native Saccharomyces cerevisiae Useful for Organic and Sulfite-Free Wine". Foods 9, nr 5 (20.05.2020): 658. http://dx.doi.org/10.3390/foods9050658.
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Sulfites and sulfides are produced by yeasts in different amounts depending on different factors, including growth medium and specific strain variability. In natural must, some strains can produce an excess of sulfur compounds that confer unpleasant smells, inhibit malolactic fermentation and lead to health concerns for consumers. In organic wines and in sulfite-free wines the necessity to limit or avoid the presence of sulfide and sulfite requires the use of selected yeast strains that are low producers of sulfur compounds, with good fermentative and aromatic aptitudes. In the present study, exploiting the sexual mass-mating spores’ recombination of a native Saccharomyces cerevisiae strain previously isolated from grape, three new S. cerevisiae strains were selected. They were characterized by low sulfide and sulfite production and favorable aromatic imprinting. This approach, that occurs spontaneously also in nature, allowed us to obtain new native S. cerevisiae strains with desired characteristics that could be proposed as new starters for organic and sulfite-free wine production, able to control sulfur compound production and to valorize specific wine types.
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Andronikov, Alexandre V., Irina E. Andronikova i Tamara Sidorinova. "Trace-Element Geochemistry of Sulfides in Upper Mantle Lherzolite Xenoliths from East Antarctica". Minerals 11, nr 7 (16.07.2021): 773. http://dx.doi.org/10.3390/min11070773.
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Sulfides in upper mantle lherzolite xenoliths from Cretaceous alkaline-ultramafic rocks in the Jetty Peninsula (East Antarctica) were studied for their major and trace-element compositions using SEM and LA-ICP-MS applied in situ. Modal abundance of sulfides is the lowest in Cpx-poor lherzolites ≤ Spl-Grt lherzolites << Cpx-rich lherzolites. Most sulfides are either interstitial (i-type) or inclusions in rock-forming minerals (e-type) with minor sulfide phases mostly present in metasomatic veinlets and carbonate-silicate interstitial patches (m-type). The main sulfide assemblage is pentlandite + chalcopyrite ± pyrrhotite; minor sulfides are polydymite, millerite, violarite, siegenite, and monosulfide solution (mss). Sulfide assemblages in the xenolith matrix are a product of the subsolidus re-equilibration of primary mss at temperatures below ≤300 °C. Platinum group elements (PGE) abundances suggest that most e-type sulfides are the residues of melting processes and that the i-type sulfides are crystallization products of sulfide-bearing fluids/liquids. The m-type sulfides might have resulted from low-temperature metasomatism by percolating sulfide-carbonate-silicate fluids/melts. The PGE in sulfide record processes are related to partial melting in mantle and intramantle melt migration. Most other trace elements initially partitioned into interstitial sulfide liquid and later metasomatically re-enriched residual sulfides overprinting their primary signatures. The extent of element partitioning into sulfide liquids depends on P, T, fO2, and host peridotite composition.
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Zhang, Ya Hui, Xi Cheng i Qing Wang. "A Low Temperature Precursor Sulfuration Route to Metal Sulfides Nanomaterials". Advanced Materials Research 148-149 (październik 2010): 1404–7. http://dx.doi.org/10.4028/www.scientific.net/amr.148-149.1404.
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A low-temperature precursor sulfuration route has been established to prepare metal sulfides with different nanostructures during the synthesis of nickel sulfide. The advantages of the low-temperature precursor sulfuration route were testified by the synthesis of different metal sulfides ( lead sulfide, zinc sulfide and cobalt sulfide). It offers a novel path to the preparation of other metal sulfides.
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Brierley, Corale L. "Biohydrometallurgy: What is its Future?" Advanced Materials Research 71-73 (maj 2009): 3–10. http://dx.doi.org/10.4028/www.scientific.net/amr.71-73.3.
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Bioleaching/minerals biooxidation and bioremediation have been widely used commercially for heap/dump bioleaching of secondary copper sulfide ores, sulfidic-refractory gold concentrates and treatment of acid rock drainage. Technical and commercial challenges, identified in this paper, remain for bioleaching of primary sulfides and complex ores. New frontiers for the technology exist in processing massive sulfides, silicate-locked minerals and in the more distant future in-situ leaching. Decommissioning of cyanide heap leach operations and stabilizing mine wastes using biotechnology are opportunities requiring intensive and focused research, development and engineering efforts.
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Kharaev, A. M., R. Ch Bazheva i A. S. Borodulin. "Halogenated polyethersulfone sulfides". E3S Web of Conferences 413 (2023): 02038. http://dx.doi.org/10.1051/e3sconf/202341302038.
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This paper presents the results of a study of random copolyethersulfone sulfides based on 4,4-dichlorodiphenylsulfone, 1,1-dichloro-2,2-di(4-hydroxyphenyl)ethylene, and sodium sulfide. The synthesis of copolyethersulfone sulfides with different ratios of polyethersulfone and polyphenylenesulfone sulfide units was carried out by high-temperature polycondensation by the reaction of nucleophilic substitution in N,N-dimethylacetamide medium and using potassium carbonate as an alkaline agent. The effect of the solvent used on the yield and reduced viscosity of polyethersulfone sulfides was studied. It has been shown that polymers with high reduced viscosity can be obtained in N,N-dimethylacetamide and N,N-dimethylformamide. The growth dynamics of the reduced viscosity of polyethersulfone sulfides was also studied depending on the ratio of sulfone and sulfide groups. The solubility of these polymers in various solvents has been studied.
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Wu, Caowei, Changchun Zou, Cheng Peng, Yang Liu, Tao Wu, Jianping Zhou i Chunhui Tao. "Numerical Simulation Study on the Relationships between Mineralized Structures and Induced Polarization Properties of Seafloor Polymetallic Sulfide Rocks". Minerals 12, nr 9 (17.09.2022): 1172. http://dx.doi.org/10.3390/min12091172.
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The induced polarization (IP) method plays an important role in the detection of seafloor polymetallic sulfide deposits. Numerical simulations based on the Poisson–Nernst–Planck equation and the Maxwell equation were performed. The effects of mineralized structures on the IP and electrical conductivity properties of seafloor sulfide-bearing rocks were investigated. The results show that total chargeability increases linearly as the volume content of disseminated metal sulfides increases when the volume content is below 20%. However, total chargeability increases nonlinearly with increasing volume content in vein and massive metal sulfides when the volume content is below 30%. The electrical resistivity of disseminated metal sulfides mainly depends on the conductivity of pore water. The electrical resistivity of vein and massive sulfides mainly depends on the volume content and the length of sulfides. Increase in the aspect ratio (0.36 to 0.93) of seafloor massive sulfides causes relaxation time constants and total chargeability to decrease. Relaxation time constants and total chargeability also decrease with increase in the tortuosity of seafloor vein sulfides from 1.0 to 1.38. This study is of great value for the electrical survey of seafloor polymetallic sulfide deposits.
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Lu, Xian Zhong, Run Wu, Ping Liu i Hai Tao Wu. "Sulfides Precipitation during Transformation of a High Sulfur Alloy Steel". Advanced Materials Research 652-654 (styczeń 2013): 958–62. http://dx.doi.org/10.4028/www.scientific.net/amr.652-654.958.
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The morphology of sulfide and abrasive resistance of a high sulfur alloy steel cast at different cooling rate were investigated in this paper. The size, volume fraction and distribution of sulfides was decreased as the solidification rate was increased. After heat treatment, many spherical sulfide were found. Most of sulfides within grains were Cr2MnS4, while sulfides at grain boundaries were mainly FeS. High sulfur alloy steel had strong abrasive resistance.
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Sato, Tomohiro, Shuhei Ishikawa, Kenichi Saitoh, Masanori Takuma i Yoshimasa Takahashi. "Evaluation of Sulfides as Solid Lubricant: Lubricity of Compounded Sulfides". Key Engineering Materials 901 (8.10.2021): 164–69. http://dx.doi.org/10.4028/www.scientific.net/kem.901.164.
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Sulfide was used as solid lubricant, and MoS2 was popular. It was used industry as powder shape. Sulfur as oil additive; ZDDP, MoTDC were also well known. These composites make tribofilm which prevent seizure, scoring and some tribological troubles. In this paper, sulfides were synthesized by powder metallurgy technics. In addition, these sulfides were mixed with bronze powders and sintered as cylindrical specimen. As a result of the friction test in the lubricated condition, tribofilm were covered with specimen surface. By XPS observation, sulfides and oxides were detected on the specimen surface. In the test, additive was not contained in the lubricant because PAO as base oil was adapted. However, sulfide in the specimen affect the making the tribofilm, especially when bornite (Cu5FeS4) was used.
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Wentrup, Curt, i Peter Kambouris. "N-Sulfides. Dinitrogen sulfide, thiofulminic acid, and nitrile sulfides". Chemical Reviews 91, nr 3 (maj 1991): 363–73. http://dx.doi.org/10.1021/cr00003a004.
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Wilkin, Richard T., i David A. Rogers. "Nickel sulfide formation at low temperature: initial precipitates, solubility and transformation products". Environmental Chemistry 7, nr 6 (2010): 514. http://dx.doi.org/10.1071/en10076.
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Environmental context Remediation technologies often rely on manipulation of redox conditions or natural redox processes to favour microbial sulfate-reduction and mineral sulfide formation for treatment of inorganic contaminants in groundwater, including nickel. However, few data are available on the structural properties, solubility and mineral transformation processes involving nickel sulfides. These data are needed in order to constrain the long term performance of groundwater remediation efforts. Abstract The formation of nickel sulfides has been examined experimentally over the temperature range from 25 to 60°C. At all conditions studied, hexagonal (α-NiS) was the initial precipitate from solution containing Ni2+ and dissolved sulfide. Freshly precipitated nickel sulfide possesses significant residual Ni–O coordination as revealed by X-ray absorption spectroscopy. With progressive aging, residual Ni–O coordination is replaced by Ni–S coordination. The formation of millerite (β-NiS, rhombohedral) was not detected in any of the synthesis experiments. In the presence of elemental sulfur, hexagonal NiS converted to polydymite (Ni3S4) and vaesite (NiS2). Thus, conversion of nickel monosulfide to thiospinel and disulfide structures appears to be redox dependent, analogous to aging and transformation processes of iron sulfides. In the absence of elemental sulfur or with only hydrogen sulfide or bisulfide present, transformation of hexagonal NiS was not observed after 1680 h at 60°C. Low-pH solubility experiments yielded a solubility product for hexagonal NiS of log Ks0 = –2.69 ± 0.26. Solubility data at pH > 3 suggest that Ni–bisulfide complexation is important in controlling the solubility of Ni in sulfidic solutions.
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Hsieh, Yuch-Ping. "The Chemical Nature of Mercury and Copper Sulfides and Its Implication for Bioavailability Assessments in Sediments". Water 16, nr 1 (24.12.2023): 70. http://dx.doi.org/10.3390/w16010070.
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Sulfur chemistry plays an important role in regulating the bioavailability of heavy metals (HMs) because HM sulfides are extremely insoluble in sediments. However, quantifying HM sulfides in sediments has been difficult because they are considered acid-extractable (AE). Previous studies also found that Hg and Cu behaved differently from other HMs in sediments. This study investigated the chemical nature of Hg and Cu sulfides and the causes of Hg and Cu anomalies in sediments. The results indicated that Hg and Cu sulfides are not mono-sulfides (HS− or S=) but bi-sulfides (S2=), which are non-acid-extractable (NAE) under nitrogen. These results explain the Hg and Cu anomalies compared to other HMs and facilitate a procedure to quantify Hg and Cu sulfides in sediments. We analyzed the AE and NAE fractions of Hg, Cu, and Zn under nitrogen in the sediments of Apalachicola Bay, North Florida. Zn was included for comparison because Zn sulfide is mono-sulfide. The NAE Hg and Cu were, on average, 97.9 ± 2.7% and 84.6%, respectively, of the total, much higher than that of Zn (24.3% of the total) in the sediments, as expected. The NAE fractions of Hg and Cu were sulfides and thus could be excluded from the bioavailability assessments.
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Hwang, Eunseo, Yoonsu Park, Jongbae Kim, Taejong Paik i Don-Hyung Ha. "Facile Sulfurization under Ambient Condition with Na2S to Fabricate Nanostructured Copper Sulfide". Nanomaterials 11, nr 9 (6.09.2021): 2317. http://dx.doi.org/10.3390/nano11092317.
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The sulfurization reaction was investigated as a promising fabrication method for preparing metal sulfide nanomaterials. Traditional sulfurization processes generally require high vacuum systems, high reaction temperatures, and toxic chemicals, utilizing complicated procedures with poor composition and morphology controllability. Herein, a facile method is reported for synthesizing nanostructured copper sulfide using a sulfurization reaction with Na2S at room temperature under non-vacuum conditions. Moreover, we demonstrate that the morphology, composition, and optical properties of nanostructured copper sulfides could be controlled by the Na2S solution concentration and the reaction time. Nanostructured copper sulfides were synthesized in nanospheres, nanoplates, and nanoplate-based complex morphologies with various oxidation states. Furthermore, by comparing the optical properties of nanostructured copper sulfides with different oxidation states, we determined that reflectivity in the near infrared (NIR) region decreases with increasing oxidation states. These results reveal that the Na2S solution concentration and reaction time are key factors for designing nanostructured copper sulfides, providing new insights for synthesis methods of metal sulfide nanomaterials.
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Band, Victor I., Apollo Stacy, Joanna Chau i Yasmine Belkaid. "Sulfides in the gut mediate protection against gastrointestinal infection via alterations to local immunity and the microbiome". Journal of Immunology 210, nr 1_Supplement (1.05.2023): 227.07. http://dx.doi.org/10.4049/jimmunol.210.supp.227.07.
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Abstract Sulfide is a gaseous molecule, which has toxic effects at high concentrations yet plays key roles in homeostasis throughout the body. Sulfides are produced endogenously by both host tissues and the bacterial cells of the gut microbiome, which results in the gut containing the highest concentrations of sulfide in the body. We sought to assess the role of the highly abundant sulfide molecule in gut immunity, microbiome homeostasis and resistance to enteric infections. Local sulfides can be depleted by the compound bismuth subsalicylate (BSS), a common anti-diarrheal medication, which acts locally by sequestering sulfides in the gut. Key gut commensals such as Lactobacillusand segmented filamentous bacteria, major mediators of gut immunity and resistance to pathogen colonization, were profoundly depleted following sulfide sequestration. Additionally, we observed significant downstream immune effects, specifically within the local immunity of the small intestine. Depletion of gut sulfides resulted in profound collapse of CD4 T cells, especially among Th1 cells in the lamina propria of the small intestine. Using a mouse model of SalmonellaTyphimurium, mice treated with BSS were extremely susceptible to infection, with a 5-log increase in fecal bacterial load at 24 hours post infection. These data reveal a central role for sulfides in gut homeostasis and prevention of enteric infection. Strategies to manage gut sulfide levels, including diet supplementation and microbiome engineering, could be a possible intervention to promote gut health. NIH Office of Dietary Supplements (Research Scholar Grant 2022)
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Kadikova, Rita, Ilfir Ramazanov, Alexey Vyatkin i Usein Dzhemilev. "Zirconium-Catalyzed Reaction of 1-Alkynyl Sulfides with Et3Al: A Novel Route to Trisubstituted 1-Alkenyl Sulfides". Synlett 29, nr 13 (21.06.2018): 1773–75. http://dx.doi.org/10.1055/s-0037-1610431.
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The reaction of 1-alkynyl sulfides and alkynyl sulfoxides with Et3Al under zirconocene catalysis conditions has been studied. The interaction between 1-alkynyl sulfides and Et3Al in the presence of catalytic amounts of Cp2ZrCl2 leads to trisubstituted 1-alkenyl sulfides in moderate to good yields (56–73%) with high regioselectivity and stereoselectivity. 1-Alkynyl sulfoxides, upon treatment with Et3Al under the same reaction conditions, undergoes reduction to give sulfides. The excess of Et3Al (7 equiv) in this reaction causes cyclic carboalumination of in situ generated 1-alkynyl sulfide to form trisubstituted 1-alkenyl sulfides in quantitative yield.
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Schovan, Samantha, Grant McEachern, Alexandria Seeger, Victor V. Nguyen, Bobby Burkes, Amitava Adhikary i Linda E. Schweitzer. "Remediation of Sulfides in Produced Waters of the Oil and Gas Industry Using Hydrogen Peroxide". Water 16, nr 14 (13.07.2024): 1987. http://dx.doi.org/10.3390/w16141987.
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Produced waters are often treated in open lagoons where hydrogen sulfide (H2S) can off gas, posing a risk to human health and the environment. The aim of this study was to optimize a treatment process using hydrogen peroxide (H2O2) to oxidize H2S while minimizing off gassing. Samples of produced water from West Texas and laboratory-prepared waters utilizing sodium sulfide (Na2S) or biogenic polysulfides were oxidized with H2O2 alone or in combination with copper or iron catalysts, sodium hydroxide (NaOH), or a commercial sulfide oxidizer, HydroPower Green™. Sulfur speciation was measured using Hach test kits for sulfide/sulfate/sulfite and Dräger tubes for headspace H2S. HydroPower Green™ (HPG) helped to reduce H2S in the headspace of water samples; some of this was pH related as NaOH also worked, but not as well as HPG. The dose of peroxide necessary to oxidize sulfides to sulfate is a function of the oxidation-reduction potential (Eh) of the water and total sulfide concentration as well as pH; approximately a 1–4:1 ratio of peroxide to sulfide concentration was needed to oxidize sulfidic waters of pH 7–10 with half-lives under 30 min. Both copper and iron catalysts reduce H2O2 demand and the half-life of H2S. Peracetic acid (PAA) and copper (II) sulfate pentahydrate (CuSO4, 5H2O) were explored as biocides for controlling sulfate-reducing bacteria (SRBs) that produce H2S. An AquaSnap (Hygenia) test kit was employed to monitor relative microbial activity in a wetland porewater containing H2S. Microbial regrowth occurred after a few days using the highest dose of PAA; these results showed that PAA was being used by bacteria as a carbon source even after the initial substantial reduction in the microbial activity. CuSO4, 5H2O at a dose of 1 ppm prevented microbial regrowth. The recommended treatment process from this research is determined by jar testing with H2O2, a base for pH control, a biocide, and possibly a metal catalyst or other co-oxidants in order to achieve oxidation of sulfides without H2S release or the precipitation of metal carbonates or oxides.
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Hillerová, Eva, i Miroslav Zdražil. "Activity and selectivity of carbon-supported transition metal sulfides in simultaneous hydrodearomatization and hydrodesulfurization". Collection of Czechoslovak Chemical Communications 54, nr 10 (1989): 2648–56. http://dx.doi.org/10.1135/cccc19892648.
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Hydrodesulfurization (HDS) and hydrodearomatization (HYD) activities of carbon-supported sulfides of V, Cr, Mn, Fe, Co, Ni, Nb, Mo, Ru, Rh, Pd, W, Re, Ir, and Pt, and of the commercial Co-Mo/Al2O3 catalysts were evaluated. Simultaneous hydrodesulfurization of benzothiophene and hydrogenation of naphthalene to tetralin at pressure of 2 MPa were used as the model reaction. Platinum group metal sulfides and Re sulfide exhibited the highest HDS activity and Pd and Rh sulfides reached the activity of a good commercial Ni-Mo catalyst. Tha catalysts strongly differed in the selectivity of dihydrobenzothiophene formation during HDS; up to 55% of dihydrobenzothiophene was obtained over W sulfide, while Rh, Ni, Co-Mo and Ni-Mo catalysts produced less than 8% of it. The highest HYD activity exhibited platinum group metal sulfides; the best were Ir and Pt sulfides which were four times and three times more active than the commercial Ni-Mo catalyst, respectively. The selectivity HDA/HDS depend strongly on the type of transition metal. The sulfides of W, Ir and Pt were much more selective for HYD than the Ni-Mo catalyst, and the Co-Mo sample showed by far the lowest HDA/HDS selectivity.
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Wang, Yi, Xiang-yu Xu, Zhi-wei Li i Jian-xun Fu. "Sulfur segregation and inclusion modification in steel using magnesium addition". Metallurgical Research & Technology 119, nr 3 (2022): 316. http://dx.doi.org/10.1051/metal/2022031.
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In order to investigate the effect of magnesium treatment on the distribution and segregation of sulfides in carbon high-sulfur free-cutting steel in industrial tests, scanning electron microscope, energy dispersive spectrometer, electrolysis device, and other characterization methods are used to examine the sulfide morphology in the steel continuous casting billet. The sulfide type, spatial distribution and three-dimensional morphology of the slab in the casting slab are analyzed, and the law of sulfur segregation is calculated and summarized using the diffusion growth model. The results of the study showed that the area of cluster-like sulfides before and after magnesium modification decreased by 6.4%, the area of chain-like sulfides reduced by 6.6%, and the area of single-type sulfides increased by 12.7%. In the magnesium modified steel, a fine composite sulfide with MgO·Al2O3 as the core is formed, which provides a heterogeneous nucleation site for the later precipitated MnS, enhancing the shape and size of the sulfide. The sulfide segregation index was reduced from 1.30 to 1.04 before and after magnesium modification, and the sulfur concentration was 1.56 times the original precipitation when the middle position of the slab was entirely cemented. The macroscopic shrinkage cavity on the surface of the cast slab is minimized after magnesium treatment, which enhances sulfide dispersion and segregation dramatically.
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Chaumba, Jeff B., i Caston T. Musa. "Formation of the main sulfide zone at Unki Mine, Shurugwi Subchamber of the Great Dyke, Zimbabwe: Constraints from petrography and sulfide compositions". Geosphere 16, nr 2 (16.01.2020): 685–710. http://dx.doi.org/10.1130/ges02150.1.
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Abstract The major platinum group element (PGE) occurrence in the Great Dyke of Zimbabwe, the main sulfide zone, is a tabular stratabound layer hosted in pyroxenites, and it is broadly similar in form throughout the length of the Great Dyke. We conducted a petrographic and sulfide composition study on a sulfide-enriched zone from the contact of the mafic sequence–ultramafic sequence through the main sulfide zone at Unki Mine in the Shurugwi Subchamber to its underlying footwall rocks to place some constraints on the origin of the rocks. Pyrrhotite, pentlandite, chalcopyrite, and pyrite are the base metal sulfides that were encountered during the study. Pyrrhotite, pentlandite, and chalcopyrite typically occurred as inclusions in both primary (orthopyroxene, plagioclase, and clinopyroxene) and secondary (amphibole and chlorite) silicate phases, whereas pyrite was observed in only three samples, where it occurred in association with pyrrhotite. The concentrations of PGEs in the base metal sulfides were nearly all at or below minimum detection limits. The intercumulus nature of some of these sulfides in the investigated sequence suggests that they were likely formed during the crystallization history of these rocks. The occurrence of pyrite, which we interpret to be an alteration phase, suggests that a late-stage event, likely formed during hydrothermal alteration, helped to concentrate the mineralization at Unki Mine. In some cases, however, these sulfides occur partially surrounding some chromite and silicate phases. Thus, some sulfides in the Unki Mine area were likely formed early in the crystallization history of the Great Dyke, whereas others were formed late during hydrothermal processes. Low concentrations of PGEs such as platinum (Pt), palladium (Pd), and rhodium (Rh) in base metal sulfides imply that the PGEs in the main sulfide zone and Unki Mine are hosted either in silicates and/or platinum group minerals. Very low Co contents in pentlandites in the rocks under investigation are interpreted to imply that very limited Fe substitution by Co, and also of Ni by Co, occurred. Broadly comparable trends, with minor variations of Fe in pyrrhotite, of Co and Ni in pentlandite, and of Cu in chalcopyrite, for example, likely reflect magmatic processes. The concentrations of these metals in base metal sulfides vary sympathetically, indicating that their original magmatic signatures were subsequently affected by hydrothermal fluids. The spiked pattern displayed by the variations in the percent modal proportions of the base metal sulfides across the entire investigated stratigraphic section is interpreted to reflect remobilization of the sulfides during hydrothermal alteration. Depletions in some elements, which occur near the base and at the top of the investigated succession, are likely a result of this hydrothermal alteration.
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Nam, Tae Hyun, Cheol Am Yu, Dae Won Jung i Kwon Koo Cho. "Fabrication of Ni Sulfides by Thermal Sulfidation". Materials Science Forum 510-511 (marzec 2006): 318–21. http://dx.doi.org/10.4028/www.scientific.net/msf.510-511.318.
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The microstructure of Ni sulfides prepared by thermal sulfidation of pure Ni and their dependence of fabrication parameters were investigated by means of scanning electron microscopy and X-ray diffractions. Sulfidation was made by isothermally annealing Ni with the sulfur in vacuum sealed glass ampoules at 673 K for 120 – 600s under the sulfur pressure of 100 and 220 kPa. The sulfide layers formed in the early stage were found to consist of spherical particles smaller than 0.5um, which were grown and agglomerated with increasing annealing temperature. Thickness of sulfides developed on Ni substrate was found to increase with increasing annealing time and sulfur pressure. It was also found that compositions of dominant Ni sulfides changed with varying annealing time. At the initial stage, only Ni3S2 sulfide was formed on pure Ni, which was tightly bonded to Ni substrate. On increasing annealing time, NiS sulfide was formed. On further increasing annealing time, NiS1.97 sulfide was formed, which always coexisted with NiS sulfide. A mechanism for sulfidation of Ni is proposed as follows: 3Ni + 2S Ni3S2, Ni3S2 +S NiS, NiS + S NiS1.97
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Nohara, Toshihiro, Yukio Fujiwara, Mona El-Aasr, Tsuyoshi Ikeda, Masateru Ono, Daisuke Nakano i Junei Kinjo. "Thiolane-type sulfides from garlic, onion, and Welsh onion". Journal of Natural Medicines 75, nr 4 (3.06.2021): 741–51. http://dx.doi.org/10.1007/s11418-021-01533-x.
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AbstractIn this paper, we review our work in the last 10 years wherein we examined the sulfides in the acetone extracts of garlic (Allium sativum), onion (A. cepa), and Welsh onion (A. fistulosum), obtained and characterized the structures of new sulfides, three 3,4-dimethylthiolane-type sulfides from onion and Welsh onion, respectively, and four acyclic-type, nine 3,4-dimethyl- thiolane-type, four 2-methylthiolane (and thiane)-type, two 1,2-dithiolane-type, and two 2-oxothiolane-type sulfides, together with (E)-ajoene and one kujounin-type sulfide from garlic. During this process, structural corrections were made in onionin A group, garlicnin A, and garlicnin B group in some 3,4-dimethylthiolane-type sulfides. Next, hypothetical pathways for the production of the aforementioned sulfides were proposed. Furthermore, it was revealed that a typical 3,4-dimethylthiolane-type sulfide, onionin A1 obtained from onion, having the isomeric structure of garlicnin B1 obtained from garlic, decreased tumor proliferation and controlled tumor metastasis. These results showed that onionin A1 is an effective agent for controlling tumors, and that the antitumor effects observed in vivo are likely caused by reversing the antitumor immune system. Activation of the antitumor immune system by onionin A1 might be an effective adjuvant therapy for patients with osteosarcoma, ovarian cancer and other malignant tumors.
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Lesher, C. M. "Up, down, or sideways: emplacement of magmatic Fe–Ni–Cu–PGE sulfide melts in large igneous provinces". Canadian Journal of Earth Sciences 56, nr 7 (lipiec 2019): 756–73. http://dx.doi.org/10.1139/cjes-2018-0177.
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The preferential localization of Fe–Ni–Cu–PGE sulfides within the horizontal components of dike–sill–lava flow complexes in large igneous provinces (LIPs) indicates that they were fluid dynamic traps for sulfide melts. Many authors have interpreted them to have collected sulfide droplets transported upwards, often from deeper “staging chambers”. Although fine (<1–2 cm) dilute (<10%–15%) suspensions of dense (∼4–5 g/cm3) sulfide melt can be transported in ascending magmas, there are several problems with upward-transport models for almost all LIP-related deposits: (1) S isotopic data are consistent with nearby crustal sources, (2) xenoliths appear to be derived from nearby rather than deeper crustal sources, (3) lateral sheet flow or sill facies of major deposits contain few if any sulfides, (4) except where there is evidence for a local S source, sulfides or chalcophile element enrichments rarely if ever occur in the volcanic components even where there is mineralization in the subvolcanic plumbing system, and (5) some lavas are mildly to strongly depleted in PGE >>> Cu > Ni > Co, indicating that unerupted sulfides sequestered PGEs at depth. Two potential solutions to this paradox are that (i) natural systems contained surfactants that lowered sulfide–silicate interfacial tensions, permitting sulfide melts to coalesce and settle more easily than predicted from theoretical/experimental studies of artificial/analog systems, and (or) (ii) sulfides existed not as uniformly dispersed droplets, as normally assumed, but as fluid-dynamically coherent pseudoslugs or pseudolayers that were large and dense enough that they could not be transported upwards. Regardless of the ultimate explanation, it seems likely that most high-grade Ni–Cu–PGE sulfide deposits in LIPs formed at or above the same stratigraphic levels as they are found.
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Dalhem, Krister, Stefan Mattbäck, Anton Boman i Peter Österholm. "A simplified distillation-based sulfur speciation method for sulfidic soil materials". Bulletin of the Geological Society of Finland 93, nr 1 (13.06.2021): 19–30. http://dx.doi.org/10.17741/bgsf/93.1.002.
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Speciation of inorganic sulfur species, mainly pyrite and metastable iron sulfides by operationally defined methods, is widely used for risk assessment of acid sulfate soils by quantifying the acidity producing elements, as well as for general characterisation of marine sediments and subaqueous soils. “Traditional” sulfur speciation methods commonly use highly specialised glassware which can be cumbersome for the operator, or, require long reaction times which limit the usability of the method. We present a simplified method which has a sufficiently low limit of detection (0.002%) and quantitation (0.006%) required for the analysis of sulfidic sulfur in acid sulfate soil materials. Commercially available sulfide reagents were used for determining reproducibility and the method was assessed on natural sulfidic soil materials, including fine to coarse grained soil materials as well as sulfide bearing peat, with a large variation of metastable sulfide and pyrite content.
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Wu, Liang. "Cu-based mutlinary sulfide nanomaterials for photocatalytic applications". AIMS Materials Science 10, nr 5 (2023): 909–33. http://dx.doi.org/10.3934/matersci.2023049.
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<abstract> <p>Due to their environmentally benign elemental components, suitable bandgap and high absorption coefficient in the visible-light range, Cu-based multinary sulfides exhibit excellent photocatalytic properties. Moreover, the adjustable atomic structure and unique electronic state of Cu-based multinary sulfide semiconductors can boost their ability to absorb visible light. In this review, we provide a summary of recent progress in photocatalytic applications of Cu-based multinary sulfide nanomaterials, including Cu-based ternary sulfides (CuInS<sub>2</sub>, CuIn<sub>5</sub>S<sub>8</sub>, Cu<sub>3</sub>SnS<sub>4</sub>, CuFeS<sub>2</sub>, etc.) and Cu-based quaternary sulfides (CuZnInS, Cu<sub>2</sub>ZnSnS<sub>4</sub>, CuZnGaS, CuInGaS, etc.). We start with a review of the bandgap alignments of Cu-based ternary sulfides and Cu-based quaternary sulfides, which are the key factors for the photocatalytic activity of semiconductor photocatalysts. Then, we discuss the advancements in photocatalytic applications of Cu-based multinary sulfide photocatalysts, including photocatalytic H<sub>2</sub> production, CO<sub>2</sub> reduction, organic synthesis and degradation of pollutants and photoelectrochemical H<sub>2</sub> production. Finally, we end this review with a summary of the current challenges and opportunities of Cu-based multinary sulfides in future studies.</p> </abstract>
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Smith, W. D., W. D. Maier, I. Bliss i L. Martin. "In Situ Multiple Sulfur Isotope and S/Se Composition of Magmatic Sulfide Occurrences in the Labrador Trough, Northern Quebec". Economic Geology 116, nr 7 (1.11.2021): 1669–86. http://dx.doi.org/10.5382/econgeo.4843.
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Abstract The interaction between mafic-ultramafic magma and crustal sulfide is considered a key process in the formation of magmatic Ni-Cu-platinum group element (PGE) sulfide deposits. Integrated S/Se and multiple sulfur isotope studies are the most robust in constraining the role of crustal sulfur during ore genesis. In the present study, we report the first integrated S/Se and multiple sulfur isotope study of magmatic sulfide occurrences in the Labrador Trough, namely, on the recently discovered Idefix PGE-Cu and Huckleberry Cu-Ni-(PGE) prospects. Whole-rock and in situ S/Se values (~810–3115) of magmatic sulfides and their host rocks are consistent with S loss during postmagmatic hydrothermal alteration, negating their use in interpreting the origin of S. Values of ∆33S ~0 indicate no record of the assimilation of Archaean sulfur. Disseminated (–0.5 to +2.5‰) and globular (3.0–4.5‰) sulfides at Idefix as well as globular sulfides (2.1–9.6‰) at Huckleberry have δ34S values greater than the accepted mantle range, suggesting that crustal S played a role in the formation of these sulfides. In contrast, disseminated and net-textured sulfides at Huckleberry have variable δ34S values (–4.6 to +3.2‰) that are mostly within the accepted mantle range, excluding one anomalous sample that records relatively higher δ34S values (11.9–15.0‰). It is proposed that sulfide melt segregated in response to the addition of small proportions of crustal S prior to the final emplacement of the host intrusions, i.e., in a feeder conduit or staging chamber. Isotopic exchange between the sulfide melt and silicate magma has diluted and, in places, eradicated a crustal δ34S signature.
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Nechvoglod, O. V., Evgeny N. Selivanov i S. V. Mamyachenkov. "Effect of Structure on the Electrochemical Oxidation Rate of Copper and Nickel Sulfides". Defect and Diffusion Forum 326-328 (kwiecień 2012): 383–87. http://dx.doi.org/10.4028/www.scientific.net/ddf.326-328.383.
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Synthesized samples were crystallized at 10 - 1000 K/sec (νcooling) to study the effect of sulfides structure on the electrochemical oxidation rates. The methods of X-ray, optical and electronic microscopy are used to analyze the phase composition, and the methods of voltamperometry and chronoamperometry are used to study the laws of electrochemical oxidation. Slow cooling of the samples with sulfide phase (Cu1,96S, Ni3S2) leads to crystallization of the metal (Ni, Cu). High cooling rate leads to crystallization of non-equilibrium phases, increasing of proportion of the sulfide phase and decreasing of metallic component up to complete disappearance. It is shown that electrochemical oxidation of copper and nickel sulfides proceeds stepwise: Me2S Me2-XS Me1+XS MeS Me2+ + S. Experiments have revealed the rates of electrochemical oxidation of granular sulfides that exceed the rates established for the slowly cooled samples. The rates of the electrochemical oxidation of Ni3S2 at potential of 1500 mV are 8.810-8 g/sec·mm2 (at vcooling = 10 К/sec) and 1.310-7 g/sec·mm2 (at νcooling = 1000 К/sec). The rates of the electrochemical oxidation of Cu2S at potential of 1000 mV are 2.810-8 g/sec·mm2 (at νcooling = 10 К/sec) and 4.310-8 g/sec·mm2 (at νcooling = 1000 К/sec). It is found that the forming of a passivation layer effects the rate of the electrochemical oxidation of copper sulfide and nickel sulfide. Non-equilibrium phase composition and refinement provide greater reactivity of sulfides in the conditions of anodic polarization. The oxidation and passivation of metallic phase along with sulfide phases proceed from the surface of Me2S Me alloys. As for the samples crystallized at 1000 K/sec only anodic oxidation of sulfides occurs due to a lack of metallic phase. The compositions of passivation films and potentials providing the extraction of sulfur in the elemental state from the sulfides crystallized at high rates were determined.
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Ma, Ming Tu, Guo Zhong Li, Zhi Gang Li i Hong Zhou Lu. "The Effect of Morphology and Distribution of Sulfides on Mechanical Properties and Fatigue Life of Non-Quenched and Tempered Steel". Advanced Materials Research 51 (czerwiec 2008): 11–20. http://dx.doi.org/10.4028/www.scientific.net/amr.51.11.
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The effect of morphology and distribution of sulfides on tensile, impact and bending fatigue properties of non-quenched and tempered steel 49MnVS3 has been investigated in this paper. Microscopic structure and morphology of sulfides are observed, and impact fracture and fatigue fracture have been analyzed by SEM. The results show that the morphology of sulfides is mostly strip and distributes in ferrite, which affects mechanical properties and fatigue life. The length direction of sulfide strip is parallel to the rolling direction of steel. When the length of sulfide is short relatively and is approximate to the shape of particles. The impact properties and bending fatigue performance of 49MnVS3 are higher. Under those conditions, there are more ductile characteristics in their impact fracture and the fatigue fracture. The reasons for the effect of sulfide morphology on the mechanical and fatigue properties are explained.
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Cong, Haoxi, Minhao Zhang i Qingmin Li. "Study on Sulfide Distribution in the Operating Oil of Power Transformers and Its Effect on the Oil Quality". Applied Sciences 8, nr 9 (7.09.2018): 1577. http://dx.doi.org/10.3390/app8091577.
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Corrosive sulfides in transformer oil could react with copper wire to produce cuprous sulfide, causing insulation failure. At present, both the quantitative measurement method and distribution of sulfur components in operating oil are not clear yet. In this paper, the existing types and contents of sulfides in oil samples with different alkyl groups and different voltage levels were investigated. With quantitative testing methods, the distribution of sulfur composition in the operating oil was analyzed. Results showed that the thiophene sulfide in transformer oil existed mainly in the form of benzothiophene with an unsaturation of 6 and dibenzothiophene with an unsaturation of 9. The content of monosulfide sulfide with unsaturation of 3 or 6 was the highest. The disulfide existed basically in the form of Dibenzyl disulfide (DBDS). The influence of sulfides on the oil quality were analyzed on this basis. Results showed that the existence of sulfides would increase the moisture content in oil. The absorbed moisture could cause the decrease of the breakdown voltage and rise of the dielectric loss. The above study could provide some engineering practice for understanding the sulphide distribution in transformer oils and further prevent the sulfur corrosion faults.
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Smith, William D., Wolfgang D. Maier i Ian Bliss. "Distribution of noble metals in magmatic sulfide occurrences in the Montagnais Sill Complex, Labrador Trough, Canada". Canadian Mineralogist 59, nr 6 (1.11.2021): 1599–626. http://dx.doi.org/10.3749/canmin.2000119.
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ABSTRACT We have characterized the distribution of noble metals among six styles of magmatic sulfide mineralization in the Montagnais Sill Complex of the Labrador Trough in northern Québec using optical and electron microscopy combined with laser ablation-inductively coupled plasma-mass spectrometry trace element analysis of sulfides. The principal sulfide minerals include pyrrhotite, chalcopyrite, and pentlandite with accessory sphalerite and sulfarsenides. In addition, cubanite, troilite, and mackinawite are present in ultramafic-hosted assemblages. The precious metal mineral assemblages are dominated by tellurides, Ag-rich gold, and sperrylite which generally occur at the margins of sulfides. Few iridium-group platinum group element- and Rh-bearing grains were identified and mass-balance calculations show that these elements are generally hosted in pyrrhotite and pentlandite. Virtually all Pt and Au are hosted in precious metal grains, whereas Pd is distributed between precious metal grains and pentlandite. Where present, sulfarsenides are a key host of iridium-group platinum group element, Rh, Pd, Te, and Au. The presence of troilite, cubanite, and mackinawite and the absence of pentlandite exsolution lamellae in the ultramafic-hosted sulfides indicates an initial sulfide melt with a high metal/S ratio. Sulfarsenides present among globular sulfide assemblages derive from an immiscible As-rich melt that exsolved from the sulfide melt in response to the assimilation of the As-bearing floor rocks. In this study, the composition of sulfides is consistent with those derived from Ni-Cu-dominated deposits and not platinum group element-dominated deposits.
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Chanturiya, Valentine A., Eugenia A. Krasavtseva i Dmitriy V. Makarov. "Electrochemistry of Sulfides: Process and Environmental Aspects". Sustainability 14, nr 18 (8.09.2022): 11285. http://dx.doi.org/10.3390/su141811285.
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One of the main sources of non-ferrous and precious metals is sulfide ores. This paper presents a review of the existing literature on the electrochemical properties of some of the most common industrial sulfides, such as pentlandite, chalcopyrite, sphalerite, galena, pyrrhotite, pyrite, etc. The study results of the surface redox transformations of minerals, galvanic effect, cathodic oxygen reduction reaction on the surface of sulfides are presented. The electrochemical properties of sulfide minerals are manifested both in the industrial processes of flotation and hydrometallurgy and in the natural geological setting or during the storage of sulfide-containing mining, mineral processing, and metallurgical industry waste.
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WENTRUP, C., i P. KAMBOURIS. "ChemInform Abstract: N-Sulfides. Dinitrogen Sulfide, Thiofulminic Acid, and Nitrile Sulfides". ChemInform 22, nr 50 (22.08.2010): no. http://dx.doi.org/10.1002/chin.199150329.
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Temmel, C., B. Karlsson i N. G. Ingesten. "Quenching cracks in medium carbon steel initiated at manganese sulfide inclusions". HTM Journal of Heat Treatment and Materials 62, nr 5 (1.10.2007): 236–42. http://dx.doi.org/10.1515/htm-2007-0009.
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Abstract Quench crack propensity has been investigated for two identical medium carbon steels (50CrMo4) which only differed in sulfur content. The standard variant of the material was affected by manganese sulfide inclusions whereas the low sulfur material was essentially free of sulfides. 80 mm, cylindrical test specimens were used. The test specimens had been cut out of cross rolled steel plates in which the manganese sulfide were flattened to discoid shape. The specimen orientation was in direction of principal deformation where the flattened sulfides were aligned with the test specimen axis. The largest sulfides reached lengths of 150 μm. Both materials were austenitized at 850 °C for 60 minutes, quenched in a salt-bath at 180 °C and immediately annealed at 425 °C for one hour. It turned out that the standard material developed quench cracks which initiated at manganese sulfide. No cracks could be found in the low sulfur material. Thermal and transformational stresses, which develop during quenching, aggravate the stress situation around the manganese sulfide and cause the cracking. The results are interpreted in fracture mechanical terms.
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Fábry, Jan, Lubomír Havlák, Monika Kučeráková i Michal Dušek. "Redetermination of NaGdS2, NaLuS2and NaYS2". Acta Crystallographica Section C Structural Chemistry 70, nr 6 (6.05.2014): 533–35. http://dx.doi.org/10.1107/s2053229614009607.
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The title structures NaGdS2(sodium gadolinium sulfide), NaLuS2(sodium lutetium sulfide) and NaYS2(sodium yttrium sulfide) were redetermined in order to improve the structural information available for the family of group 1 and thallium rare earth sulfides, which are isostructural with the rhombohedral α-NaFeO2structure type. In particular, the present investigation has been directed at the rhombohedral sodium rare earth sulfides. The observed dependence of the fractional coordinatez(S2−) on the identity of the rare earth element in the newly determined structures is in agreement with the known structures of the potassium and rubidium analogues. Crystals of NaGdS2and NaLuS2display obverse–reverse twinning.
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Le Bras, Loic Y., Robert Bolhar, Lunga Bam, Bradley M. Guy, Grant M. Bybee i Paul A. M. Nex. "Three-dimensional textural investigation of sulfide mineralisation from the Loolekop carbonatite–phoscorite polyphase intrusion in the Phalaborwa Igneous Complex (South Africa), with implications for ore-forming processes". Mineralogical Magazine 85, nr 4 (31.03.2021): 514–31. http://dx.doi.org/10.1180/mgm.2021.32.
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AbstractCopper-sulfides within carbonatites and phoscorites of the Phalaborwa Igneous Complex, South Africa, have been investigated since the middle of the 20th Century. However, aspects of ore formation have remained unclear. This study examines the mechanisms involved in Cu-sulfide mineralisation by micro-focus X-ray computed tomography as applied to sulfide-rich drill core samples. Several texturally distinct assemblages of magmatic sulfides can be identified, including: (1) <500 μm rounded bornite and chalcopyrite grains disseminated within the gangue; (2) elongated mm-scale assemblages of chalcopyrite and bornite; and (3) mm-to-cm thick chalcopyrite cumulates. Chalcopyrite veins were also observed, as well as late-stage valleriite, documenting late-stage fluid circulation within the pipe, and alteration of magmatic and hydrothermal sulfides along fractures within the gangue, respectively. The results of micro-focus X-ray computed tomography indicate that magmatic sulfides are sub-vertically aligned. Spatial variability of the sulfide assemblages suggests that textural changes within sulfide layers reflect fluctuating magma flow rate during emplacement of carbonatite–phoscorite magmas, through coalescence or breakup of sulfide liquid droplets during ascent. Modal sulfide abundances, especially for disseminated assemblages, differ from one carbonatite–phoscorite layer to another, suggesting a strong control of the mechanical sorting in the formation of Cu-sulfide textures within the Loolekop carbonatite. The alternation of carbonatite and phoscorite within the intrusion suggest that the Loolekop Pipe was emplaced through a series of successive magma pulses, which differentiated into carbonatite and phoscorite by melt immiscibility/progressive fractional crystallisation and pressure drop. Three-dimensional textural analysis represents an effective tool for the characterisation of magma flow and is useful for the understanding of magmatic processes controlling sulfide liquid-bearing phoscorite–carbonatite magmas.
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Vysotskiy, Sergey V., Tatyana A. Velivetskaya, Aleksandr V. Ignatiev i Anna V. Aseeva. "Atmosphere and biological impact during sulfide formation in the Archean Central-Vozhma sulfide deposit (Karelia)". Bulletin of the Tomsk Polytechnic University Geo Assets Engineering 335, nr 7 (23.07.2024): 111–20. http://dx.doi.org/10.18799/24131830/2024/7/4388.
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Relevance. The need of new knowledge about the early stages of the Earth. Sulfur isotope analysis of sulfide minerals is a powerful tool to understand the processes during the Archaean and Paleoproterozoic. Combined with other data, isotope geochemistry provides an insight into sulfur sources of sulfides from ancient sulfide volcanosedimentary deposits; geochemical factors affecting Archaean sulfide volcanosedimentary ore formation; adjust genetic models and determine the degree of influence of bacteria on the mineral formation. Aim. To identify the sources of sulfur during the formation of sulfide deposits via isotope analysis, and to evaluate bacteria affect mineral formation. Objects. They were obtained from the core of boreholes of Mesoarchaean volcanosedimentary sulfide Central-Vozhma deposit, being a part of the Sumozersko-Kenozersky greenstone belt of the Karelian craton. Methods. Mineralogical studies of rock and ore samples were carried out using optical microscopy; scanning electron microscopy and energy dispersive X-ray spectroscopy. The ratios of four stable sulfur isotopes were analyzed in sulfide minerals of the deposit (33S/32S, 34S/32S, 36S/32S). Results. The results obtained demonstrated the polygenic source of sulfur in sulfides. The sulfides have both positive and negative Δ33S values, indicating the presence of atmospheric sulfur formed under UV photolysis during mineral formation. Sulfide minerals include the following components: Seawater sulfate sulfur of photolytic genesis showed a negative anomaly Δ33S (∼ –0.4‰). It was the source of authigenic pyrite. Sulfides crystallized as a result of biological sulfate reduction demonstrated a narrow range of δ34S values (–2.64‰˂0˂+4.27‰). Elemental sulfur of photolytic genesis mobilized from the host sedimentary rocks by hydrothermal fluids. This sulfur, with a positive Δ33S anomaly (up to +1.6‰) took part in the massive sulfide ores formation.
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Firstova, Anna, Georgy Cherkashov, Tamara Stepanova, Anna Sukhanova, Irina Poroshina i Victor Bel’tenev. "New Data for the Internal Structure of Ultramafic Hosted Seafloor Massive Sulfides (SMS) Deposits: Case Study of the Semenov-5 Hydrothermal Field (13°31′ N, MAR)". Minerals 12, nr 12 (12.12.2022): 1593. http://dx.doi.org/10.3390/min12121593.
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The internal structure of Seafloor Massive Sulfides (SMS) deposits is one of the most important and complex issues facing the study of modern hydrothermal ore systems. The Semenov-5 hydrothermal field is a unique area where mass wasting on the slope of the oceanic core complex (OCC) structure exposes the subsurface portion of the deposit and offers an exceptional opportunity to observe massive sulfides that have formed not only on the seafloor but in sub-seafloor zones as well. This paper examines the internal structure of the OCC-related Semenov-5 hydrothermal field along with analysis of the mineralogy and chemistry of different parts of sulfide deposit. The seafloor deposit is comprised of pyrite, marcasite, hematite, goethite, lepidocrocite, rare pyrrhotite, isocubanite and Co-rich pyrite. Sulfide chemistry indicates the prevailing influence of ultramafics on their composition irrespective of the spatial relation with basalt lavas. Sub-seafloor mineralization is associated with ultramafic rocks and is represented by massive and disseminated sulfides. Pyrrhotite, isocubanite, pyrite, chalcopyrite, Co-rich pyrite, quartz with rutile, quarts with hematite and Cr-spinels are fixed in massive subseafloor mineralization. The presence of Cr-spinels as well as a very high Cr content are regarded as indicators of the metasomatic nature of this part of the deposit that had formed as a result of ultramafic replacement. As a result, three zones of a hydrothermal ore-forming system have been described: massive sulfides precipitated from hot vents on the surface of the seafloor, massive sulfides formed due to replacement of ultramafics below the seafloor and disseminated sulfide mineralization-filled cracks in hosted rocks which have formed stockwork around metasomatic massive sulfides. Despite differences in the mineral and geochemical composition of sub-seafloor and seafloor mineralization, all minerals subject to the sample formed as a consequence of fluid circulation in ultramafic rocks and were linked by a common ore-forming process.
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Westner, Katrin J., Christoph Beier, Reiner Klemd, Inga Osbahr i Nadine Brooks. "In Situ Chalcophile and Siderophile Element Behavior in Sulfides from Moroccan Middle Atlas Spinel Peridotite Xenoliths during Metasomatism and Weathering". Minerals 9, nr 5 (4.05.2019): 276. http://dx.doi.org/10.3390/min9050276.
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In situ chalcophile and siderophile major and trace elements were analyzed in sulfides from eight Moroccan Middle Atlas lherzolite xenoliths using electron microprobe and laser ablation inductively coupled plasma mass spectrometry. The sulfides occur enclosed in primary silicates, interstitial in the peridotite matrix, and associated with glass-bearing melt pockets. Monosulfide solid solutions are enriched in these xenoliths relative to pentlandite and intermediate solid solutions. Regardless of the textural occurrence, sulfide platinum-group element (PGE) patterns are distinguished into residual ([Pd/Ir]N < 1 and [Pt/Pd]N > 1 or [Pt/Pd]N < 1), melt-like ([Pd/Ir]N > 1), and unfractionated patterns. The coexistence of both residual and melt-like PGE signatures on a cm scale in a single sample implies that sulfides may record initial depletion and subsequent re-enrichment more effectively than constituent silicates do. Chalcophile and siderophile trace elements other than the PGEs are fractionated between the precipitated sulfide phases, but do not vary systematically with the PGE signatures, suggesting that the PGEs are comparatively sensitive to melting and depletion. In addition, Fe-rich hydroxides generated by sulfide breakdown due to atmospheric weathering display PGE systematics almost identical to their precursor sulfides, implying that they may be reliable tracers of mantle processes even after extensive weathering.
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Mansur, Eduardo, Sarah-Jane Barnes i Cesar F. Ferreira Filho. "The effects of post-cumulus alteration on the distribution of chalcophile elements in magmatic sulfide deposits and implications for the formation of low-S-high-PGE zones: The Luanga deposit, Carajás Mineral Province, Brazil". Canadian Mineralogist 59, nr 6 (1.11.2021): 1453–84. http://dx.doi.org/10.3749/canmin.2100018.
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ABSTRACT Most of the World's platinum-group element ore deposits occur as thin stratiform layers within layered intrusions. These layers generally contain disseminated base-metal sulfides or chromite. However, cryptic platinum-group element deposits also occur without chromite or base-metal sulfides in what are known as low-S-high platinum-group element deposits. The origin of these deposits is not clearly understood. The Luanga Complex hosts the largest platinum-group elements resource in South America (i.e., 142 Mt at 1.24 ppm Pt + Pd + Au and 0.11% Ni) and hosts both a platinum-group element deposit containing disseminated base-metal sulfides (style 1) and a low-S-high platinum-group element deposit (style 2). It therefore offers the opportunity to compare the two deposit types in the same overall geological setting and consider how the low-S-high platinum-group element deposit could have formed. The first deposit style is termed the Sulfide zone and consists of a 10–50 meter-thick interval with disseminated base metal sulfides, whereas the second style is named low-S-high-Pt-Pd zone and consists of 2–10 meter-thick discontinuous lenses of 1–5 meter-thick sulfide- and oxide-free harzburgite and orthopyroxenite with discrete platinum-group minerals. Secondary assemblages commonly replace primary igneous minerals to a variable extent throughout the deposit, and thus allow for investigating the effects of post-cumulus alteration on the distribution of a wide range of chalcophile elements in a magmatic sulfide deposit at both whole-rock and mineral scale. This study presents the whole-rock distribution of S, platinum-group elements, and Te, As, Bi, Sb, and Se in both mineralization styles and the concentration of trace elements in base-metal sulfides from the Sulfide zone. The Sulfide zone has Pt/Pd ratios around 0.5 and high concentrations of Te, As, Bi, Sb, and Se, whereas the low-S-high-platinum-group element zone has Pt/Pd ratios greater than 1 and much lower Se, Te, and Bi concentrations, but comparable As and Sb contents. This is reflected in the platinum-group element assemblage, comprising bismuthotellurides in the Sulfide zone and mostly arsenides and antimonides in the low-S, high platinum-group elements zone. Moreover, the base-metal sulfides from the Sulfide zone have anomalously high As contents (50–500 ppm), which suggest that the sulfide liquid segregated from a very As-rich silicate magma, possibly illustrated by an average komatiitic basalt that assimilated a mixture of upper continental crust and black shales. We interpret the low-S-high platinum-group elements zone as a product of S loss from magmatic sulfides during post-cumulus alteration of the Luanga Complex. Selenium, Te, Bi, and Pd were also lost together with S, whereas As and Sb were expelled from base-metal sulfide structures and combined with platinum-group elements to form platinum-group minerals, suggesting they may play a role fixating platinum-group elements during alteration. The remobilization of chalcophile elements from magmatic sulfide deposits located in the Carajás Mineral Province may represent a potential source for hydrothermal deposits found in the region.
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Su, Lijuan, Jun Tian, Shaoyan Hu, Ming Lv, Xianglong Li, Tianpeng Qu, Deyong Wang i Tianyin Zhan. "Effect of Ca/Mg on Distribution and Morphology of MnS Inclusions in 45MnVS Non-Quenched and Tempered Steel". Metals 13, nr 1 (22.12.2022): 23. http://dx.doi.org/10.3390/met13010023.
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The influence of Ca treatment, Mg treatment and Ca–Mg combined treatment on the inclusions in 45MnVS non-quenched and tempered steel were studied in the present work. After the melting experiment, a hot rolling test was carried out on the steel ingot. Additionally, the composition, quantity and morphology of inclusions in the test steel samples were analyzed by automatic scanning electron microscopy (ASPEX) and an energy dispersive X-ray spectrometer connected to scanning electron microscope (SEM-EDS). The results indicated that the inclusions in 45MnVS steel mainly consisted of a large amount of sulfides and a small amount of oxides. Sulfide inclusions could be nucleated and precipitated using oxides as a core during solidification. The proportion of spindle-shaped inclusions in sulfide with smaller sizes was higher. The sizes of MnS–oxide inclusions were larger than those of MnS. After hot rolling, the proportion of spindle-shaped MnS and complex sulfides with oxide cores in the samples was increased significantly. Compared with Ca treatment and Ca–Mg treatment, more oxides were formed in the steel with Mg treatment, which can in turn become the cores for sulfide nucleation and precipitation. Thus, the proportion of MnS–oxide inclusions in steel increased. Compared with Ca treatment and Mg treatment, steel with Ca–Mg treatment was more conducive to the formation of complex sulfides, and increased the proportion of spindle-shaped sulfides in 45MnVS steel. After Ca treatment, Mg treatment and Ca–Mg combined treatment, the proportions of spindle-shaped sulfides in steel were 23.31%, 19.39% and 43.24%, respectively.
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Ciazela, Jakub, Jaroslaw Bakala, Miroslaw Kowalinski, Stefan Plocieniak, Natalia Zalewska, Bartosz Pieterek, Tomasz Mrozek i in. "Concept and Design of Martian Far-IR ORE Spectrometer (MIRORES)". Remote Sensing 14, nr 12 (10.06.2022): 2799. http://dx.doi.org/10.3390/rs14122799.
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Sulfide ores are a major source of noble (Au, Ag, and Pt) and base (Cu, Pb, Zn, Sn, Co, Ni, etc.) metals and will, therefore, be vital for the self-sustainment of future Mars colonies. Martian meteorites are rich in sulfides, which is reflected in recent findings for surface Martian rocks analyzed by the Spirit and Curiosity rovers. However, the only high-resolution (18 m/pixel) infrared (IR) spectrometer orbiting Mars, the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM), onboard the Mars Reconnaissance Orbiter (MRO), is not well-suited for detecting sulfides on the Martian surface. Spectral interference with silicates impedes sulfide detection in the 0.4–3.9 μm CRISM range. In contrast, at least three common hydrothermal sulfides on Earth and Mars (pyrite, chalcopyrite, marcasite) have prominent absorption peaks in a narrow far-IR (FIR) wavelength range of 23–28 μm. Identifying the global distribution and chemical composition of sulfide ore deposits would help in choosing useful targets for future Mars exploration missions. Therefore, we have designed a new instrument suitable for measuring sulfides in the FIR range called the Martian far-IR Ore Spectrometer (MIRORES). MIRORES will measure radiation in six narrow bands (~0.3 µm in width), including three bands centered on the sulfide absorption bands (23.2, 24.3 and 27.6 µm), two reference bands (21.5 and 26.1) and one band for clinopyroxene interference (29.0 µm). Focusing on sulfides only will make it possible to adapt the instrument size (32 × 32 × 42 cm) and mass (<10 kg) to common microsatellite requirements. The biggest challenges related to this design are: (1) the small field of view conditioned by the high resolution required for such a study (<20 m/pixel), which, in limited space, can only be achieved by the use of the Cassegrain optical system; and (2) a relatively stable measurement temperature to maintain radiometric accuracy and enable precise calibration.
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Hassan, Hidaya, Jacob Kaavera, Akira Imai, Kotaro Yonezu, Thomas Tindell, Kenzo Sanematsu i Koichiro Watanabe. "Cu-Au-Platinum Group Element Mineralization in the Mbesa Prospect, Southern Tanzania: Unconventional Magmatic Sulfides". Economic Geology 119, nr 3 (1.05.2024): 643–64. http://dx.doi.org/10.5382/econgeo.5068.
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Abstract High-grade Cu mineralization was recently discovered in the Mbesa prospect in southern Tanzania, but its origin is poorly constrained. Herein, we present new major element, trace element, rare earth element (REE), and platinum group element (PGE) geochemistry and petrographic data to constrain the origin of the mineralization. The sulfide mineralization is dominated by chalcopyrite and bornite and characterized by high Cu/Ni over 100 in the massive and disseminated ores. The mineralization lacks pyrrhotite and pentlandite, which are found commonly in magmatic Ni-Cu-PGE sulfide deposits. Platinum group minerals present are michenerite (PdBiTe) and sudburyite (PdSb). PGE concentrations expressed as Pd + Pt + Au are up to 1.31 and 1.04 ppm in the massive and disseminated ores, respectively. The δ34S of chalcopyrite separates range from –3.9 to –0.6‰, bornite separates vary from –1.8 to 1.1‰, and bornite-chalcopyrite mixtures yield –1.3 and 0.6‰, mostly consistent with a magmatic sulfur origin. The sulfides are hosted by coarse-grained plagioclase amphibolite and hornblende gneiss with recrystallization textures suggestive of metamorphism. Both rocks are characterized by enrichment in large ion lithophile elements (LILEs), with negative anomalies of Zr and Nb, consistent with crustal contamination of magmas derived from partial melting of subcontinental lithospheric mantle (SCLM). An SCLM origin is further suggested by the close association of Cu sulfides with carbonates and apatite. It is suggested that the sulfides crystallized from the fractionated Cu-rich sulfide melt enriched in intermediate solid solution (iss) at shallow crustal levels. Sulfide were likely mobilized as droplets attached to CO2 vapor phase as expressed by close association between carbonates and apatite with the Cu-rich sulfides. Nickel-rich sulfides may remain undiscovered at deeper portions around the Mbesa prospect.
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Kepezhinskas, Nikita. "Fluid-induced metamorphism and anatexis of refractory Ni-Co-Cu sulphides in subduction-related rocks". E3S Web of Conferences 98 (2019): 08008. http://dx.doi.org/10.1051/e3sconf/20199808008.
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The role of metamorphism on refractory sulfides is not well constrained. Although experiments have displayed the effectiveness of high grade metamorphism, namely granulite facies metamorphism, on sulfide anatexis, its role in the presence of other variables is still poorly understood. Rocks from the Bay Islands Accretionary Complex in Honduras and the Ildeus-Lucha Complex in Russia exhibit extensive metamorphism. Sulfide mineralization is prolific in these rocks suggesting that metamorphism has played an important role in re-concentrating these sulfides during amphibolite and granulite facies metamorphism.
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Oikawa, Katsunari, Hajime Mitsui i Kiyohito Ishida. "A Thermodynamic Database for Fe-Cr-Mn-Ni-Ti-S-C-N System". Materials Science Forum 500-501 (listopad 2005): 711–18. http://dx.doi.org/10.4028/www.scientific.net/msf.500-501.711.
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A database for thermodynamic information of sulfides and carbo-sulfide in steels has been developed, where the thermodynamic properties of the relevant constituting sub-system of the complex system have been assessed by the CALPHAD (Calculation of Phase Diagrams) approach. The utility of this database is demonstrated in examples of phase diagram calculations of low carbon steels and stainless steels. The calculated results are in good agreement with experimental data. The developed thermodynamic database would be useful in predicting the formation of sulfides and carbo-sulfides in the commercial steels.
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Cruz-Reyes, J., M. Avalos-Borja, M. H. Farias i S. Fuentes. "Electron Microscopy in hydrodesulfurization catalysts". Proceedings, annual meeting, Electron Microscopy Society of America 48, nr 4 (sierpień 1990): 260–61. http://dx.doi.org/10.1017/s0424820100174436.
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Applications of transition metal sulfides for hydroprocessing catalysts have included a variety of reactions. It is generally believed that an interaction between the active phase (Mo or W) and the promoter (Co or Ni) takes place. Several models have been suggested to explain the enhanced catalytic activity. The catalytic properties of the unsupported sulfides are dependent on the catalyst preparation methods . In this work we study by electron microscopy two sets of unsupported samples ranging from molybdenum sulfide to cobalt sulfide. The specimens were prepared by the following methods, a slight variation of the classical homogeneous sulfide precipitation (HSP) method, and a new method called impregnated thiosalt decomposition (ITD).
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Myles, Daniel J. T., M’hamed Chahma i Robin G. Hicks. "Synthesis and properties of end-capped bis(oligothienyl) sulfides". Canadian Journal of Chemistry 86, nr 10 (1.10.2008): 982–91. http://dx.doi.org/10.1139/v08-128.
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The synthesis, and the optical and electrochemical properties, of a series of mesitylthio (MesS-) end-capped bis(oligothienyl) sulfides are presented. The target compounds were synthesized principally by convergent protocols, whereby a series of short thiophene oligomers bearing one terminal mesitylthio (MesS-) substituent were first assembled by metal-catalyzed cross-coupling reactions and then coupled via divalent sulfur through reactions with bis(phenylsulfonyl) sulfide. The spectroscopic and electrochemical features of the bis(oligothienyl) sulfides are qualitatively similar to those of the related mesitylthio-capped fully conjugated oligothiophenes, suggesting that the degree of electronic communication between the two oligothiophene chromophores in the bis(oligothienyl) sulfides is low. Cyclic voltammetry studies on the bis(oligothienyl) sulfides reveal that these species can be reversibly oxidized to radical cations, but the reversibility of subsequent oxidations depends on oligothienyl chain length and the presence and position of more electron-rich ethylenedioxythiophene (EDOT) groups. In general, the bis(oligothienyl) sulfides possess fewer than the expected number of reversible oxidations based on comparisons with their corresponding mesitylthio-capped fully conjugated oligothiophenes; excessive charge accumulation at or near the central linking sulfur atom is believed to be responsible for the irreversible behavior. Analysis of the irreversible voltammetric response of one of the bis(oligothienyl) sulfides leads to the suggestion of a decomposition mechanism for the cationic species involving carbon-sulfur bond cleavage and subsequent coupling of thiophene fragments — a finding with potential implications for the poor environmental stability of doped poly(p-phenylene sulfide), one of the prototypical conducting polymers.Key words: conjugated materials, conducting polymers, oligothiophenes, electronic communication.
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Chashchin, V. V., i V. N. Ivanchenko. "Sulfide PGE–Cu–Ni and Low-Sulfide Pt–Pd Ores of the Monchegorsk Ore District (Arctic Western Sector): Geology, Mineralogy, Geochemistry, and Genesis". Russian Geology and Geophysics 63, nr 4 (1.04.2022): 519–42. http://dx.doi.org/10.2113/rgg20214410.
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Abstract During the recent exploration of the Monchegorsk ore district (MOD) in the Arctic western sector, the platinum potential of known Cu–Ni deposits (Nittis-Kumuzhya-Travyanaya (NKT), Nyud, Ore Horizon 330 (OH330), and Terrasa) has been assessed, and new sulfide PGE–Cu–Ni deposits (Western Nittis) and manifestations (Moroshkovoe Ozero, Poaz, and Arvarench), and low-sulfide Pt–Pd deposits (Loipishnyun, Southern Sopcha, and Vuruchuaivench) have been discovered. All of them are confined to Paleoproterozoic (ca. 2.5 Ga) layered intrusions (the Monchegorsk pluton (Monchepluton) and the Monchetundra massif) and are divided into two types according to their structural position: basal, located in the marginal parts of intrusions, and reef-type (stratiform). All types of ores show Pd specialization. Platinum group minerals (PGM) have a limited composition in sulfide PGE–Cu–Ni ores and are represented by predominant Pt and Pd compounds with Bi and Te and subordinate PGE arsenides and sulfides. Low-sulfide Pt–Pd ores are characterized by a significant variety of PGM, with a predominance of PGE sulfides, bismuthide-tellurides, and arsenides. Sulfide PGE–Cu–Ni deposits and manifestations (Western Nittis, NKT, Nyud, Moroshkovoe Ozero, Poaz, and Arvarench) formed through the accumulation of base metal sulfides and PGE in immiscible sulfides and their subsequent segregation in commercial contents. The reef-type OH330 deposit and Terrasa manifestation resulted from the injection of additional portions of sulfur-saturated magma. The basal-type low-sulfide Pt–Pd deposits (Loipishnyun and Southern Sopcha) formed from residual melts enriched in ore components and fluids separated and crystallized during long-term oreforming processes. The reef-type Vuruchuaivench deposit is the result of deep fractionation of the parental magma with the formation of a sulfide liquid enriched in Cu and PGE. Significant reserves and large predicted resources of sulfide PGE–Cu–Ni and low-sulfide Pt–Pd ores are a reliable mineral resource base for the development of the mining industry in the Kola region of the Arctic western sector.
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Serov, P. A., R. I. Kadyrov i A. O. Kalashnikov. "X-RAY COMPUTED MICROTOMOGRAPHY OF SULFIDE MINERALS: MICROINCLUSION STUDIES AND IMPLICATIONS FOR ORE GENESIS Sm–Nd DATING". Доклады Российской академии наук. Науки о Земле 508, nr 2 (1.02.2023): 216–22. http://dx.doi.org/10.31857/s2686739722601855.
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A microtomographic study of the internal structure of sulfide minerals from ore varieties of rocks of two industrial deposits of the Arctic zone of the Russian Federation – disseminated ore of the Pilgujarvi Cu–Ni deposit of Pechenga and ore gabbronorites of the platinum-bearing Fedorovo-Pansky complex (Kola Peninsula) was carried out. It is shown that all studied sulfide samples have a homogeneous structure without obvious defects or silicate inclusions larger than 1 µm. The absence of silicate microinclusions larger than one micron in sulfides suggests an isomorphic form of REE occurrence in sulfides and, to some extent, eliminates the debatable problem of the influence of microinclusions on the results of Sm–Nd isotope-geochronological studies of sulfides. The presence of smaller (10–500 nm) silicate microinclusions is highly likely to be unable to control the total REE budget in a sulfide mineral. The conclusion about the absence of a significant effect of microinclusions on the obtained ages is confirmed by the results of Sm–Nd dating using sulfides from the same mineral samples: the Sm–Nd ages of the ores of the Pilgujarvi Cu–Ni deposit were 1965 ± 87 Ma; ore gabbronorites of the Fedorovo-Pansky complex – 2482 ± 61 Ma, which is in good agreement with the dates obtained earlier using other isotopic systems (U–Pb, Re–Os).
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Daurenbek, M., i A. Bakibaev. "Study of the microstructure of the complex sulphide compound ZnIn". BULLETIN of the L.N. Gumilyov Eurasian National University. Chemistry. Geography. Ecology Series 132, nr 3 (2020): 61–72. http://dx.doi.org/10.32523/2616-6771-2020-132-3-61-72.
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Currently, the production of new inorganic materials based on the sulfides synthesis is a major and promising direction. This is due to the obvious society needs for highly sensitive, fast-acting as well as economically attractive materials for various science branches and technologies. Such materials include ZnIn sulfide which has already found various practical applications.This work describes the methods for synthesis of sulfide material. The synthesis of the indicated sulfide was carried out by the developed methods.The obtained material was analyzed on an energy dispersive spectrometer М.Ә. Дәуренбек, А.А. Бакибаев 72Quantax 70, which allows for X-ray mapping, line elemental analysis and multielement point analysis. The specific features of the material microstructure and a surface nature of its structural elements are revealed.The obtained results make possible to predict many physicochemical properties of complex sulfides compounds and to judge their changes under various influences. Knowledge about microstructure features of such material as well as understanding of complex processes that affect its properties is an indispensable condition for new materials creation based on complex sulfides
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Wagenhofer, Manuel F., Hui Shi, Oliver Y. Gutiérrez, Andreas Jentys i Johannes A. Lercher. "Enhancing hydrogenation activity of Ni-Mo sulfide hydrodesulfurization catalysts". Science Advances 6, nr 19 (maj 2020): eaax5331. http://dx.doi.org/10.1126/sciadv.aax5331.
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Unsupported Ni-Mo sulfides have been hydrothermally synthesized and purified by HCl leaching to remove Ni sulfides. Unblocking of active sites by leaching significantly increases the catalytic activity for dibenzothiophene hydrodesulfurization. The site-specific rates of both direct (hydrogenolytic) and hydrogenative desulfurization routes on these active sites that consist of coordinatively unsaturated Ni and sulfhydryl groups were identical for all unsupported sulfides. The hydrogenative desulfurization rates were more than an order of magnitude higher on unsupported Ni-Mo sulfides than on Al2O3-supported catalysts, while they were similar for the direct (hydrogenolytic) desulfurization. The higher activity is concluded to be caused by the lower average electronegativity, i.e., higher base strength and polarity, of Ni-Mo sulfides in the absence of the alumina support and the modified adsorption of reactants enabled by multilayer stacking. Beyond the specific catalytic reaction, the synthesis strategy points to promising scalable routes to sulfide materials broadly applied in hydrogenation and hydrotreating.
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Senftle, F. E., i D. B. Wright. "Synthesis of Au2S and Au2S3 Using H2S, Short-Chain and Ring-Structured Sulfur as Sulfur Sources". Zeitschrift für Naturforschung B 41, nr 9 (1.09.1986): 1081–84. http://dx.doi.org/10.1515/znb-1986-0904.
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Abstract To determine which of the two known gold sulfides (containing either mono- or trivalent gold) are formed by reacting trivalent gold with differnt allotropes of sulfur, experiments were made using three different sources of sulfur. When trivalent gold in the form of Au2(SO4)3 in concentrated acid is reacted with electrolytically formed short-chain sulfur, monovalent gold sulfide (Au2S) is formed. If hydrogen sulfide gas reacts with the same solution, trivalent gold sulfide (Au2S3) is produced. Alternatively, if ordinary a-sulfur (ring structure) is used, a 50/50 mixture of Au2S and Au2S3 is formed. The synthesis procedure for the two gold sulfides is substantially simpler than previously reported methods of preparation