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Journal articles on the topic 'Silicates de fer'

Author: Grafiati

Published: 4 June 2021

Last updated: 1 July 2022

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1

Trudu, Federica, Gloria Tabacchi, and Ettore Fois. "Computer modeling of apparently straight bond angles: The intriguing case of all-silica ferrierite." American Mineralogist 104, no. 11 (2019): 1546–55. http://dx.doi.org/10.2138/am-2019-6951.

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Abstract The relationships between synthetic zeolites and their natural counterparts that have been unveiled by theoretical studies have contributed to improving the properties and applications of zeolite-based materials in strategic areas such as industrial catalysis, environmental protection, and solar energy harvesting. To pinpoint the role of modeling in zeolite science, we discuss an example of computationally driven problem solving: can tetrahedral frameworks sustain straight (i.e., 180°) Si-O-Si bond angles? The true crystal symmetry of zeolite ferrierite (FER), especially in its all-si

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2

Ghio, A. J., T. P. Kennedy, A. R. Whorton, A. L. Crumbliss, G. E. Hatch, and J. R. Hoidal. "Role of surface complexed iron in oxidant generation and lung inflammation induced by silicates." American Journal of Physiology-Lung Cellular and Molecular Physiology 263, no. 5 (1992): L511—L518. http://dx.doi.org/10.1152/ajplung.1992.263.5.l511.

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Inhalation of silicates induces a variety of lung diseases in humans. The molecular mechanism(s) by which these dusts cause disease is not known. Because several naturally occurring mineral oxides have large amounts of transition metal ions on their surfaces, we tested the hypothesis that surface complexation of iron may be an important determinant of their ability to induce disease. Silica, crocidolite, kaolinite, and talc complexed considerable concentrations of Fe3+ onto their surfaces from both in vitro and in vivo sources. The potential biological importance of iron complexation was asses

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3

Zvereva, V. P., K. R. Frolov, and A. I. Lysenko. "Chemical reactions and conditions of mineral formation at tailings storage facilities of the Russian Far East." Gornye nauki i tekhnologii = Mining Science and Technology (Russia) 6, no. 3 (2021): 181–91. http://dx.doi.org/10.17073/2500-0632-2021-3-181-191.

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Cassiterite-sulfide and polymetallic deposits of the Far Eastern Region (FER) were mined by both openpit and underground methods. This resulted in the emerging numerous mine workings and tailings storage facilities (TSFs) (abandoned without reclamation in latest decades) and the formation of mining technogenic mineralogical systems. Sulfide component of minerals in the mining technogenic system is subjected to hypergenic and technogenic processes (oxidation and hydrolysis reactions). As a result, highly concentrated technogenic solutions are formed, from which minerals of various classes preci

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4

Champness, P. E., and R. W. Devenish. "Elemental mass loss in silicate minerals during x-ray analysis." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 4 (1990): 804–5. http://dx.doi.org/10.1017/s0424820100177155.

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It has long been recognised that silicates can suffer extensive beam damage in electron-beam instruments. The predominant damage mechanism is radiolysis. For instance, damage in quartz, SiO2, results in loss of structural order without mass loss whereas feldspars (framework silicates containing Ca, Na, K) suffer loss of structural order with accompanying mass loss. In the latter case, the alkali ions, particularly Na, are found to migrate away from the area of the beam. The aim of the present study was to investigate the loss of various elements from the common silicate structures during elect

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5

Sanghani, Manish N., Luc Lajaunie, Kuljeet Kaur Marhas, et al. "Microstructural and Chemical Investigations of Presolar Silicates from Diverse Stellar Environments." Astrophysical Journal 925, no. 2 (2022): 110. http://dx.doi.org/10.3847/1538-4357/ac3332.

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Abstract We report the structural and chemical investigation of nine presolar silicate grains from the CH3/CBb3 chondrite Isheyevo and CR2 chondrite Northwest Africa (NWA) 801. Five of these grains belong to group 1, likely condensed in low- to intermediate-mass asymptotic giant branch (AGB) stars, super-AGB stars, or core-collapse supernovae, while the remaining four grains belong to group 4 and have a supernova origin. The advanced transmission electron microscopy and associated electron spectroscopy analyses show a diverse range of chemical and structural compositions for presolar silicates

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6

Hawthorne, Frank C., Yulia A. Uvarova, and Elena Sokolova. "A structure hierarchy for silicate minerals: sheet silicates." Mineralogical Magazine 83, no. 1 (2018): 3–55. http://dx.doi.org/10.1180/mgm.2018.152.

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AbstractThe structure hierarchy hypothesis states that structures may be ordered hierarchically according to the polymerisation of coordination polyhedra of higher bond-valence. A hierarchical structural classification is developed for sheet-silicate minerals based on the connectedness of the two-dimensional polymerisations of (TO4) tetrahedra, where T = Si4+ plus As5+, Al3+, Fe3+, B3+, Be2+, Zn2+ and Mg2+. Two-dimensional nets and oikodoméic operations are used to generate the silicate (sensu lato) structural units of single-layer, double-layer and higher-layer sheet-silicate minerals, and th

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7

Bataleva, Yuliya, Yuri Palyanov, Yuri Borzdov, Ivan Novoselov, and Oleg Bayukov. "Graphite and Diamond Formation in the Carbide–Oxide–Carbonate Interactions (Experimental Modeling under Mantle P,T-Conditions)." Minerals 8, no. 11 (2018): 522. http://dx.doi.org/10.3390/min8110522.

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Experimental modeling of the formation of graphite and diamond as a result of carbide–fluid interactions was performed in the Fe3C–SiO2–Al2O3–(Mg,Ca)CO3 systems at 6.3 and 7.5 GPa and 1100–1650 °C. In the experiments with ƒO2-gradient (7.5 GPa, 1250–1350 °C), graphite + magnesiowüstite + garnet ± cohenite assemblage was formed. Graphite was produced through the redox interactions of carbide with carbonate or CO2 (reducing conditions), and redox reactions of magnesiowüstite and CO2 (oxidizing conditions). At 1450–1650 °C, crystallization of graphite, garnet, magnesiowüstite and ferrospinel, as

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8

Skinner, C. J., M. J. Barlow, K. Justtanont, and R. J. Sylvester. "Mid-IR Spectra of AGB and Post-AGB Stars." Symposium - International Astronomical Union 155 (1993): 321. http://dx.doi.org/10.1017/s0074180900171098.

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We have generated models of complete nova energy distributions, including the effects of the nova dust shell emission and absorption. In order to account for the dust, we require optical constants throughout the UV and EUV. Draine & Lee (1984) is the only source of such data for silicates. However, their ‘astronomical silicate’ has a strong resonance in the UV which causes circumnova dust to be heated far above its sublimation temperature in our models of Nova Her 1991. We have therefore recalculated the silicate optical constants, using the Kramers-Kronig relations, including a λ−1.0 far-

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9

Zafar, T., K. E. Heintz, A. Karakas, J. Lattanzio, and A. Ahmad. "Silicon and iron dust in gamma-ray burst host galaxy absorbers." Monthly Notices of the Royal Astronomical Society 490, no. 2 (2019): 2599–605. http://dx.doi.org/10.1093/mnras/stz2827.

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ABSTRACT Depletion studies provide a way to understand the chemical composition of interstellar dust grains. We here examine 23 gamma-ray bursts (GRBs) optical afterglow spectra (spanning 0.6 ≤ z ≤ 5.0) and compare their silicon and iron dust-phase column densities with different extinction curve parameters to study the composition of the interstellar dust grains in these high-redshift GRB host galaxies. The majority of our sample (87 per cent) show featureless extinction curves and only vary in shape. We observe strong correlations (with $\gt 96{{\ \rm per\ cent}}$ significance) between the t

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10

Shchipalkina, Nadezhda V., Igor V. Pekov, Natalia N. Koshlyakova, et al. "Unusual silicate mineralization in fumarolic sublimates of the Tolbachik volcano, Kamchatka, Russia – Part 2: Tectosilicates." European Journal of Mineralogy 32, no. 1 (2020): 121–36. http://dx.doi.org/10.5194/ejm-32-121-2020.

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Abstract. This second of two companion articles devoted to silicate mineralization in fumaroles of the Tolbachik volcano (Kamchatka, Russia) reports data on chemistry, crystal chemistry and occurrence of tectosilicates: sanidine, anorthoclase, ferrisanidine, albite, anorthite, barium feldspar, leucite, nepheline, kalsilite, sodalite and hauyne. Chemical and genetic features of fumarolic silicates are also summarized and discussed. These minerals are typically enriched with “ore” elements (As, Cu, Zn, Sn, Mo, W). Significant admixture of As5+ (up to 36 wt % As2O5 in sanidine) substituting Si is

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Mookherjee, Mainak, Simon A. T. Redfern, and Ming Zhang. "Far-infrared spectra of ammonium layer and framework silicates." Neues Jahrbuch für Mineralogie - Monatshefte 2004, no. 1 (2004): 1–9. http://dx.doi.org/10.1127/0028-3649/2004/2004-0001.

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12

Day, Maxwell C., and Frank C. Hawthorne. "A structure hierarchy for silicate minerals: chain, ribbon, and tube silicates." Mineralogical Magazine 84, no. 2 (2020): 165–244. http://dx.doi.org/10.1180/mgm.2020.13.

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AbstractA structure hierarchy is developed for chain-, ribbon- and tube-silicate based on the connectedness of one-dimensional polymerisations of (TO4)n− tetrahedra, where T = Si4+ plus P5+, V5+, As5+, Al3+, Fe3+, B3+, Be2+, Zn2+ and Mg2+. Such polymerisations are described by a geometrical repeat unit (with ng tetrahedra) and a topological repeat unit (or graph) (with nt vertices). The connectivity of the tetrahedra (vertices) in the geometrical (topological) repeat units is denoted by the expression cTr (cVr) where c is the connectivity (degree) of the tetrahedron (vertex) and r is the numbe

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13

Hervig, R. L., J. V. Smith, and J. B. Dawson. "Lherzolite xenoliths in kimberlites and basalts: petrogenetic and crystallochemical significance of some minor and trace elements in olivine, pyroxenes, garnet and spinel." Transactions of the Royal Society of Edinburgh: Earth Sciences 77, no. 3 (1986): 181–201. http://dx.doi.org/10.1017/s026359330001083x.

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ABSTRACTElectron and ion microprobe analyses for P, Si, Ti, Al, Cr, V, Sc, Fe, Mn, Mg, Ni, Co, Ca, Sr, Na, K and Li in olivine, pyroxenes and garnet in forty-two cold and twelve hot garnet lherzolites from kimberlites, nine spinel lherzolites from kimberlites and eighteen from alkali basalts, and one cold garnet lherzolite from the Malaita alnöite, are compared with published data for minerals occurring in lherzolite, harzburgite and eclogite xenoliths, for silicate megacrysts in kimberlites, and for silicate inclusions in diamonds. Despite wide ranges in the chemistry of minerals from garnet

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14

Filippi, Sara, Miriam Cappello, Manuel Merce, and Giovanni Polacco. "Effect of Nanoadditives on Bitumen Aging Resistance: A Critical Review." Journal of Nanomaterials 2018 (November 27, 2018): 1–17. http://dx.doi.org/10.1155/2018/2469307.

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Starting from the eighties, the use of nanoadditives registered an increasing attention in the scientific and patent literature, especially for the case of polymeric nanocomposites. In the last decade, this involved bituminous materials, modified either with nanosized fillers or with polymeric nanocomposites. One of the expected benefits is an increased resistance of the binder to aging. After a short introduction underlining the uncertainties and risks of artefacts in aging tests, a review is given, focusing on the antiaging properties of layered silicates, which are by far the most important

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15

SUGAWARA, Toru, Yoshihisa FUJITA, Mitsuo KATO, Satoshi YOSHIDA, Jun MATSUOKA, and Yoshinari MIURA. "Evaluation of voltammetric redox potential for Fe3+/Fe2+ in silicate liquids." Journal of the Ceramic Society of Japan 117, no. 1372 (2009): 1317–23. http://dx.doi.org/10.2109/jcersj2.117.1317.

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16

Inui, Tomoyuki, Hideo Nagata, Osamu Yamase, et al. "Methanol to hydrocarbon conversion on Fe-silicates prepared from Fe2+ and Fe3+ sources." Applied Catalysis 24, no. 1-2 (1986): 257–71. http://dx.doi.org/10.1016/s0166-9834(00)81274-9.

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17

Dyar, M. Darby, Emily W. Lowe, Charles V. Guidotti, and Jeremy S. Delaney. "Fe3+and Fe2+partitioning among silicates in metapelites: A synchrotron micro-XANES study." American Mineralogist 87, no. 4 (2002): 514–22. http://dx.doi.org/10.2138/am-2002-0414.

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18

Marcus, Matthew A., and Phoebe J. Lam. "Visualising Fe speciation diversity in ocean particulate samples by micro X-ray absorption near-edge spectroscopy." Environmental Chemistry 11, no. 1 (2014): 10. http://dx.doi.org/10.1071/en13075.

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Environmental context Iron-bearing particles in the ocean have attracted interest due to the role of iron as an essential nutrient for microscopic algae, which form the base of the marine food chain. Modern techniques make it possible to analyse individual particles of iron to determine their composition, but the resulting flood of data can be overwhelming. We show a method of simplifying the data to answer such questions as what groups of minerals are present and whether they are different between ocean basins. Abstract It is a well known truism that natural materials are inhomogeneous, so an

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19

Velde, B., and R. Couty. "Far infrared spectra of hydrous layer silicates." Physics and Chemistry of Minerals 12, no. 6 (1985): 347–52. http://dx.doi.org/10.1007/bf00654345.

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20

Chayka, Ivan F., Liudmila M. Zhitova, Tatiana N. Antsiferova, et al. "In-Situ Crystallization and Continuous Modification of Chromian Spinel in the “Sulfide-Poor Platinum-Group Metal Ores” of the Norilsk-1 Intrusion (Northern Siberia, Russia)." Minerals 10, no. 6 (2020): 498. http://dx.doi.org/10.3390/min10060498.

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Layers rich in chromian spinel (Cr-spinel) occur in numerous differentiated and layered intrusions. These layers are often characterized by elevated and even economic concentrations of platinum-group-elements (PGEs), but only scarce sulfide mineralization. One particular type of such lithology occurs in the roof parts of the Norilsk-type differentiated intrusions (Russia) and is referred to as the “sulfide-poor PGE ores”. We investigated rocks containing variable enrichments in Cr-spinel, sulfides, and platinum-group minerals (PGMs) from two sections of the upper zone of the Norilsk-1 intrusio

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21

Štyriaková, Iveta, and Michal Lovás. "Biological Purification of Silicate Minerals." Advanced Materials Research 20-21 (July 2007): 126–29. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.126.

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Bioleaching is technology applicable to iron extraction from low-grade non-metallic raw materials. Bioleaching of quartz sands and feldspars involves the action of heterotrophic bacteria. Impurities include fine – grained limonite, goethite, hematite or mica were removed by the reductive dissolution of Fe3+ in linked with the silicate mineral destruction. Heterotrophic bacteria produced organic acids that are able to solubilize Fe oxide and silicates but require organic carbon as a source of energy. Molasses is a relatively inexpensive carbon source used for various industrial fermentations an

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22

Williams, David A. "Grains in Diffuse Clouds: Carbon-Coated Silicate Cores." Symposium - International Astronomical Union 135 (1989): 367–73. http://dx.doi.org/10.1017/s0074180900125379.

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A new model of interstellar grains is proposed in which grains in diffuse clouds consist of small (radius ≲ 10nm) and large asymmetric (0.05μm – 0.25μm) silicate cores thinly coated with mantles of amorphous carbon (thickness ≲ 5nm). This model can account successfully for many of the observed properties of interstellar dust and gives a simple interpretation of the interstellar extinction curve. The extinction bump at 220nm is attributed to absorption by finely divided silicates, as indicated by laboratory data. The large silicates provide a “grey” background extinction through the visual and

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23

Mysen, Bjorn O. "Redox equilibria and coordination of Fe2+ and Fe3+ in silicate glasses from 57Fe mossbauer spectroscopy." Journal of Non-Crystalline Solids 95-96 (December 1987): 247–54. http://dx.doi.org/10.1016/s0022-3093(87)80117-5.

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24

Sharygin, Victor V., Grigory A. Yakovlev, Richard Wirth, et al. "Nataliakulikite, Ca4Ti2(Fe3+,Fe2+)(Si,Fe3+,Al)O11, a New Perovskite-Supergroup Mineral from Hatrurim Basin, Negev Desert, Israel." Minerals 9, no. 11 (2019): 700. http://dx.doi.org/10.3390/min9110700.

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Nataliakulikite, Ca4Ti2(Fe3+,Fe2+)(Si,Fe3+,Al)O11, is a mineral intermediate between perovskite CaTiO3 and brownmillerite Ca2(Fe,Al)2O5. It was discovered as a minor mineral in a high-temperature pyrometamorphic larnite-gehlenite rock at the Nahal Morag Canyon of the Hatrurim Basin, Israel. Nataliakulikite is associated with larnite, flamite, gehlenite, magnesioferrite, Fe3+-rich perovskite, fluorapatite, barite, Hashemite, and retrograde phases (afwillite, hillebrandite, portlandite, calcite, ettringite, hydrogarnet, and other hydrated Ca-silicates). The mineral forms brown subhedral or prism

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Schreyeck, L., P. Caullet, J. C. Mougenel, J. L. Guth, and B. Marler. "PREFER: a new layered (alumino) silicate precursor of FER-type zeolite." Microporous Materials 6, no. 5-6 (1996): 259–71. http://dx.doi.org/10.1016/0927-6513(96)00032-6.

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26

Sossi, Paolo A., Antony D. Burnham, James Badro, Antonio Lanzirotti, Matt Newville, and Hugh St C. O’Neill. "Redox state of Earth’s magma ocean and its Venus-like early atmosphere." Science Advances 6, no. 48 (2020): eabd1387. http://dx.doi.org/10.1126/sciadv.abd1387.

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Exchange between a magma ocean and vapor produced Earth’s earliest atmosphere. Its speciation depends on the oxygen fugacity (fO2) set by the Fe3+/Fe2+ ratio of the magma ocean at its surface. Here, we establish the relationship between fO2 and Fe3+/Fe2+ in quenched liquids of silicate Earth-like composition at 2173 K and 1 bar. Mantle-derived rocks have Fe3+/(Fe3++Fe2+) = 0.037 ± 0.005, at which the magma ocean defines an fO2 0.5 log units above the iron-wüstite buffer. At this fO2, the solubilities of H-C-N-O species in the magma ocean produce a CO-rich atmosphere. Cooling and condensation o

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Tabatabaei Dakhili, S. Yasin, Stephanie A. Caslin, Abayomi S. Faponle, Peter Quayle, Sam P. de Visser, and Lu Shin Wong. "Recombinant silicateins as model biocatalysts in organosiloxane chemistry." Proceedings of the National Academy of Sciences 114, no. 27 (2017): E5285—E5291. http://dx.doi.org/10.1073/pnas.1613320114.

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The family of silicatein enzymes from marine sponges (phylum Porifera) is unique in nature for catalyzing the formation of inorganic silica structures, which the organisms incorporate into their skeleton. However, the synthesis of organosiloxanes catalyzed by these enzymes has thus far remained largely unexplored. To investigate the reactivity of these enzymes in relation to this important class of compounds, their catalysis of Si–O bond hydrolysis and condensation was investigated with a range of model organosilanols and silyl ethers. The enzymes’ kinetic parameters were obtained by a high-th

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28

Pìnarlì, V., and G. M. Saul. "Calcium Silicates as Lime Substitute." Water Science and Technology 28, no. 1 (1993): 257–61. http://dx.doi.org/10.2166/wst.1993.0057.

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An experimental study has been carried out of the removal of iron from solutions of ferric chloride by lime, β-dicalcium silicate (C2S) and α-monocalcium silicate (CS) and of the treatment of the resulting sludge. C2S promoted the flocculation of iron precipitates to achieve higher settling, thickening and dewatering rates. The effect of first minute settling time is especially evident that 60% and 22% of the iron respectively was removed when 0.39 g/l of C2S and 0.21 g/l of lime were applied to solutions containing 100 mg/l Fe3+. 99% and 48% of the iron respectively was removed in the first t

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Mutschke, H., S. Zeidler, Th Posch, F. Kerschbaum, A. Baier, and Th Henning. "Far-infrared spectra of hydrous silicates at low temperatures." Astronomy & Astrophysics 492, no. 1 (2008): 117–25. http://dx.doi.org/10.1051/0004-6361:200810312.

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30

Dyar, M. D., M. W. Schaefer, E. C. Sklute, and J. L. Bishop. "Mössbauer spectroscopy of phyllosilicates: effects of fitting models on recoil-free fractions and redox ratios." Clay Minerals 43, no. 1 (2008): 3–33. http://dx.doi.org/10.1180/claymin.2008.043.1.02.

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AbstractClay minerals are ubiquitous constituents in soils on Earth, are occasionally found in meteorites, and may also occur on planetary surfaces in the presence of water. However, little is known about the fundamental Mössbauer parameters (the intrinsic isomer shift, δI, the characteristic Mössbauer temperature, θM, and the recoil-free fraction, f) that are characteristic of clay minerals and critical to the correct interpretation of the Fe3+/ΣFe ratios as well as the mineral modes. Spectra of well characterized single mineral samples at multiple temperatures may be used for the determinati

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Tarasevich, Yu I., and A. V. Pustovit. "Interpreting the optical spectra of trace Fe2+ in layer silicates." Theoretical and Experimental Chemistry 23, no. 4 (1988): 435–38. http://dx.doi.org/10.1007/bf00536363.

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Gleeson, S. A., C. R. M. Butt, and M. Elias. "Nickel Laterites: A Review." SEG Discovery, no. 54 (July 1, 2003): 1–18. http://dx.doi.org/10.5382/segnews.2003-54.fea.

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ABSTRACT Nickel laterite deposits are formed by the prolonged and pervasive weathering of Ni silicate-bearing ultramafıc rocks, generally in tropical to subtropical climates. The deposits can be further classifıed as hydrous silicate deposits (e.g., SLN Operations, New Caledonia), clay silicate deposits (e.g., Murrin Murrin, Australia), and oxide deposits (e.g., Moa Bay, Cuba; Cawse, Australia) on the basis of the ore mineralogy. The physical and chemical nature of a nickel laterite deposit is a function of many factors, including the composition of the parent rock, the tectonic setting, clima

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Meechoowas, Ekarat, Parida Jampeerung, Kanit Tapasa, and Tepiwan Jitwatcharakomol. "The Decolorizing of High Iron Containing Soda-Lime Silicate Glass by Annealing Process." Key Engineering Materials 702 (July 2016): 130–34. http://dx.doi.org/10.4028/www.scientific.net/kem.702.130.

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The tableware soda-lime silicate glasses, contained with 0.06 wt% of iron oxide, which were annealed at different times and temperatures, were investigated by UV-Vis spectroscopy. The glasses were produced from high iron sand. The iron content was twice as high in the glasses as it is in normal tableware glasses. The redox reaction of iron around glass transition temperature, Fe2+(green) ↔ Fe3+(yellow), was found in the annealing process, according to the redox reaction of iron with polyvalent ions in the glass, nFe3+ + Ma+ ↔ nFe2+ + M(a+-n) where M is the polyvalent ion in glass. In this stud

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34

Roex, Anton P. Le, and Ronald T. Watkins. "A rapid ion chromatographic method for the determination of the Fe3+/Fe2+ ratio in silicate rocks and minerals." GEOCHEMICAL JOURNAL 29, no. 1 (1995): 85–89. http://dx.doi.org/10.2343/geochemj.29.85.

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35

Berdnikov, N. V., V. G. Nevstruev, P. K. Kepezhinskas, V. O. Krutikova, N. S. Konovalova, and I. A. Astapov. "SILICATE, IRON OXIDE AND COPPER-GOLD-SILVER MICROSPHERULES IN ORES AND PYROCLASTICS OF THE KOSTENGINSKOYE IRON ORE DEPOSIT (RUSSIAN FAR EAST)." Tikhookeanskaya Geologiya 40, no. 3 (2021): 67–84. http://dx.doi.org/10.30911/0207-4028-2021-40-3-67-84.

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Iron-oxide ores and pyroclastics from the Kostenginskoye deposit in the Malyi Khingan (Russian Far East) contain numerous silicate, iron-oxide, and copper-gold-silver microspherules. Silicate spherules are composed of immiscible iron- and silica-rich glasses, gas cavities and mineral inclusions. Iron-oxide spherules include magnetite with minor ilmenite and Fe-rich silicate glass. Copper-gold-silver spherules contain inclusions predominantly of copper oxide compositions. The studied microspherules are considered to have formed during the rapid ascent of metal-silicate melts from depth and thei

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Koike, Chiyoe, та Hiroshi Shibai. "Measurement of Far-Infrared Absorption for Amorphous Silicates between 27 and 400 μm". International Astronomical Union Colloquium 126 (1991): 121–24. http://dx.doi.org/10.1017/s0252921100066628.

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AbstractThe far-infrared extinction of various silicates was measured in the 27 - 400 μm range of wavelength. The SiO2content of our samples distributes between 45 and 100 weight (wt.)%. There is no distinct absorption band in the far-infrared region and the extinction decreases in proportion toλ−1.4.

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Kolitsch, Uwe, and Ekkehart Tillmanns. "The structural relation between the new synthetic silicate K2ScFSi4O10 and narsarsukite, Na2(Ti,Fe3+)(O,F)Si4O10." European Journal of Mineralogy 16, no. 1 (2004): 143–49. http://dx.doi.org/10.1127/0935-1221/2004/0016-0143.

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Mateus, António, Jorge Figueiras, Ivo Martins, Pedro Rodrigues, and Filipe Pinto. "Relative Abundance and Compositional Variation of Silicates, Oxides and Phosphates in the W-Sn-Rich Lodes of the Panasqueira Mine (Portugal): Implications for the Ore-Forming Process." Minerals 10, no. 6 (2020): 551. http://dx.doi.org/10.3390/min10060551.

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Panasqueira is a world-class W-Sn-Cu lode-type deposit located in Portugal. It consists of a dense swarm of subhorizontal quartz lodes criss-crossed by several ENE–WSW and N–S fault zones, bordering Late Variscan granite and hosted in Late Ediacaran—Early Cambrian metasediments. The relative abundance and compositional variation (assessed with EPMA) of the main silicates, oxides and phosphates forming the quartz lodes and their margins were examined, aiming to explore: (i) mineral and geochemical zonation at the mine scale; and (ii) some conclusions on the chemical nature of prevalent fluid in

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Ettler, Vojtěch, Martin Mihaljevič, Ladislav Strnad, et al. "Mineralogy of Ga- and Ge-bearing metallurgical slags from Tsumeb, Namibia." Mineralogical Magazine 85, no. 6 (2021): 879–89. http://dx.doi.org/10.1180/mgm.2021.83.

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AbstractGallium (Ga) and germanium (Ge) are technologically important critical elements. Lead blast furnace slags from Tsumeb, Namibia, comprise over two million metric tons of material that contains high levels of Ga (135–156 ppm) and Ge (128–441 ppm) in addition to significant Zn concentrations (up to 11 wt.%) and represent a potential resource for these elements. A combination of mineralogical and chemical methods (PXRD, FEG-SEM-EPMA and LA-ICP-MS) indicated different partitioning of Ga and Ge within the individual slag phases. Gallium is predominantly bound in small euhedral crystals of Zn

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Štyriaková, Iveta. "Influence of Chelators on Iron Solubilization from Quartz and Feldspars by Bioleaching." Advanced Materials Research 20-21 (July 2007): 87–90. http://dx.doi.org/10.4028/www.scientific.net/amr.20-21.87.

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Ultra-fine iron particles are difficult to treat by conventional mineral processing methods. Thus bioleaching is an attractive alternative for effective removal of iron minerals. The removal of oxidic Fe-phases from industrial silicates via bioleaching needs to be optimized with regard to the rate of iron reduction and dissolution. A new role for chelators as the low addition of AQDS or NTA during bacterial quality improvement of non-metallics, resulted in stimulating of Fe dissolution under non-controlled anaerobic conditions. AQDS stimulated bacterial iron reduction and Fe2+ concentration in

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Kaewkhao, Jakrapong, N. Srisittipokakun, Keerati Kirdsiri, C. Kedkaew, and Pichet Limsuwan. "Optical and Physics Investigation of Fe₂O₃Doped in Soda-Lime Silicate Glass at Different Melting Temperature." Applied Mechanics and Materials 103 (September 2011): 97–101. http://dx.doi.org/10.4028/www.scientific.net/amm.103.97.

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In this work, the effects of melting temperature (1200, 1300, 1400 and 1500 °C) on glass properties, prepared in the composition 64.4SiO2: 10.0CaO: 25.0Na2O: 0.6Fe2O3 have been investigated. The Fe2O3 doped glass shown green color due to the homogeneous distribution of Fe3+ and Fe2+ ions in the glass matrices. Refractive index, dielectric constant, optical dielectric constant and the reflection loss increases when the melting temperature is increased. The absorption bands are observed in the all spectra with the peaks around 380 and 435 nm are attributed to Fe3+ and board peak around 1,050 nm

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Nesbitt, H. W., and K. N. Dalby. "High resolution O 1s XPS spectral, NMR, and thermodynamic evidence bearing on anionic silicate moieties (units) in PbO-SiO2 and Na2O-SiO2 glasses." Canadian Journal of Chemistry 85, no. 10 (2007): 782–92. http://dx.doi.org/10.1139/v07-085.

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Recent technical advances in X-ray photoelectron spectroscopy (XPS) have largely overcome differential charging of insulator surfaces, with the result that O 1s linewidths for silicates can be routinely collected that are 50% to 100% narrower than had been previously obtainable. The bridging and nonbridging oxygen signals of glasses are well resolved and now can be accurately measured by XPS without resorting to ad hoc fitting procedures. All O 1s spectra of silicates collected so far are somewhat asymmetric to the high binding energy side of the peak, a characteristic due primarily to vibrati

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Meechoowas, Ekarat, Benjamon Petchareanmongkol, Parida Jampeerung, and Kanit Tapasa. "The Effect of Decolorizing Agent on the Optical Properties of High Iron Contents Soda-Lime Silicate Glass." Key Engineering Materials 766 (April 2018): 28–33. http://dx.doi.org/10.4028/www.scientific.net/kem.766.28.

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The aim of this study is to decolorize the high iron content (more than 0.1 %wt Fe2O3) glass. The contained 0.13 wt% iron oxide (Fe2O3) soda-lime silicate is prepared by high iron content sand with 0.17 wt% of Fe2O3. Iron oxide in soda-lime glass presents in two forms, Fe2+(green) « Fe3+(yellow). In principle, high iron content sand is not suitable to produce tableware. Therefore, the glass manufactures require high purity of sand because they want to control the amount of iron oxide as low as possible, which usually tableware glass contains only small amount of iron oxide (0.01 - 0.04 wt% Fe2

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J. Ghio, Robert J. Pritchard, James, Andrew. "LUNG INFLAMMATION AFTER EXPOSURE TO NONFIBROUS SILICATES INCREASES WITH CHELATABLE [Fe3+]." Journal of Toxicology and Environmental Health Part A 49, no. 1 (1996): 11–28. http://dx.doi.org/10.1080/009841096160961.

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Larimer, John W., and Ermanno R. Rambaldi. "The Trace Element Chemistry of the Metal in IAB Iron Meteorites." Zeitschrift für Naturforschung A 44, no. 10 (1989): 968–78. http://dx.doi.org/10.1515/zna-1989-1009.

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Abstract Metal grains from a silicate inclusion in Landes, a group IAB iron-meteorite, were separated and analyzed via IN A A for 14 siderophile elements. The same 14 elements were determined in matrix metal from Landes, 5 other IAB meteorites and three anomalous iron meteorites. Compared to the other samples and to chondritic metal, the inclusion metal is enriched in siderophile elements. In chondritic metal, the siderophile element contents are higher when Fe0 is oxidized to FeO. Silicates in IAB inclusions contain little FeO, yet the metal is as rich in siderophile elements as the most oxid

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Pannaparayil, T., R. Marande, and S. Komarneni. "Fe3+‐substituted silicate gels: Precursors for zeolite‐based catalysts." Journal of Applied Physics 69, no. 8 (1991): 6010–12. http://dx.doi.org/10.1063/1.347795.

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Anandarao, B. G., and S. R. Pottasch. "Far infrared observations on the peculiar variable star R Aquarii." Symposium - International Astronomical Union 122 (1987): 477. http://dx.doi.org/10.1017/s0074180900157080.

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First results on the peculiar Mira variable star R Aquarii obtained by the Infrared Astronomical Satellite (IRAS) in the far-infrared region (12–100 microns) are presented. A simple radiative transfer model for plane, isothermal and homogeneous layer is given to interpret the far-infrared excess radiation in terms of circumstellar dust emission. A two dust shell model with silicate grains is proposed to explain the observed fluxes. This model explains as well the low-resolution spectra (LRS) in the 8–20 micron region from IRAS. The equivalent sizes of the emitting regions (shells) in R Aquarii

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Yin, Yu Xia, Rui Jin Hu, Wei Qiang Liu, Ming Yue, and Zhi Chao Zhen. "Comparison and Analysis of Sodium Silicate and Epoxy Bonded NdFeB Magnets." Materials Science Forum 852 (April 2016): 136–41. http://dx.doi.org/10.4028/www.scientific.net/msf.852.136.

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Sodium silicate bonded and epoxy bonded magnetic NdFeB materials are fabricated, respectively. The magnetic properties, temperature coefficient, heat-corrosion and compressive strength of both bonded magnets are investigated. Results reveal that sodium silicate bonded magnet has a similar comprehensive property to epoxy bonded one. Compared to the epoxy bonded magnets, the sodium silicate bonded NdFeB has better temperature coefficient between 20 and 100 °C. The α value of the sodium silicate bonded NdFeB is-0.127 %/°C while the β value is-0.275 %/°C between 20 and 200 °C. DSC thermogram shows

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Meechoowas, Ekarat, Suwipa Poosrisoma, Parida Jampeerung, and Tepiwan Jitwatcharakomol. "The Effect of Heat Treatment on Fe²⁺/Fe³⁺ Ratio in Soda-Lime Silicate Glass." Key Engineering Materials 659 (August 2015): 194–98. http://dx.doi.org/10.4028/www.scientific.net/kem.659.194.

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The redox reaction of a tableware soda-lime silicate glass contained with 0.04 - 1.00 wt% of iron oxide is investigated by UV-Vis spectroscopy. The quality and purity of raw materials, especially sand is required to control the amount of iron oxide as low as possible. Normally tableware glass contains small amount of iron oxide (0.01 - 0.04 wt%) and iron effect (green color) is controlled by adding decolorizing agent. The heat treatment around transition temperature is another method to decolorize iron by redox reaction control. It is believed that the reaction of iron oxide Fe2+(green) « Fe3+

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Yatsenko, Elena A., B. M. Goltsman, and A. V. Ryabova. "Complex Protection of Pipelines Using Silicate Materials Based on Local Raw Materials of the Far East." Materials Science Forum 945 (February 2019): 46–52. http://dx.doi.org/10.4028/www.scientific.net/msf.945.46.

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Modern trends in the development of the oil and gas infrastructure of the Russian Far East are considered. The main threats in the operation of oil and gas pipelines are described. The technology of complex protection of pipeline surfaces is proposed. Protection of the inner surface is achieved through the use of silicate enamel coatings, protection of the external surface – through the use of foam glass. On the basis of local silicate raw materials the technology of the described materials is developed, and their main properties are determined. Recommendations on the application of the develo

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