scholarly journals The Reactivity of New Zealand Ilmenites

2021 ◽  
Author(s):  
◽  
James Bernard Metson
Keyword(s):  
New Zealand ◽  
Electron Microprobe ◽  
Extended Period ◽  
Absorption Spectrometry ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
X Ray ◽  
Dominant Feature ◽  
Rapid Dissolution ◽  
Series Of Experiments

<p>The dissolution of West Coast, South Island, New Zealand ilmenite in acid solutions was studied under a variety of conditions, including concentrations approaching those used industrially. The major dissolution medium considered was hydrochloric acid (1-->10 M), at temperatures of 50-->80 degrees C. The series of experiments undertaken souqht to establish the factors affecting the reactivity of the ilmenite samples. Concentrations of dissolved components of the ilmenite were followed by Atomic Absorption spectrometry and the structure and composition of the residual ilmenite was examined by X-ray powder diffraction, X-ray fluorescence, electron microprobe and scanning electron microscopy. Evidence for the rapid dissolution of an iron-rich surface phase was observed, but the dominant feature of early reaction is selective attack along zones parallel to the basal plane of the ilmenite structure. After the initial phase of rapid dissolution, reaction rate declines and all extended period of concentration/time linearity follows. This decline in rate appears to relate to polymerisation and. transport of dissolved titanium within the porous solid. The addition of phosphate and fluoride to the system, has been shown to seriously affect the properties and transport of dissolved titanium. The effects of other interfering reagents such as additional titanium and iron were also considered. The observed behaviour of these ilmenites in dissolution, was related to the pattern of natural weathering identified in other ilmenite concentrates The structure and composition of a range of these materials was examined by X-ray diffraction, Electron microprobe and Mossbauer spectroscopy.</p>

scholarly journals The Reactivity of New Zealand Ilmenites

2021 ◽  
Author(s):  
◽  
James Bernard Metson
Keyword(s):  
New Zealand ◽  
Electron Microprobe ◽  
Extended Period ◽  
Absorption Spectrometry ◽  
X Ray Diffraction ◽  
Factors Affecting ◽  
X Ray ◽  
Dominant Feature ◽  
Rapid Dissolution ◽  
Series Of Experiments

<p>The dissolution of West Coast, South Island, New Zealand ilmenite in acid solutions was studied under a variety of conditions, including concentrations approaching those used industrially. The major dissolution medium considered was hydrochloric acid (1-->10 M), at temperatures of 50-->80 degrees C. The series of experiments undertaken souqht to establish the factors affecting the reactivity of the ilmenite samples. Concentrations of dissolved components of the ilmenite were followed by Atomic Absorption spectrometry and the structure and composition of the residual ilmenite was examined by X-ray powder diffraction, X-ray fluorescence, electron microprobe and scanning electron microscopy. Evidence for the rapid dissolution of an iron-rich surface phase was observed, but the dominant feature of early reaction is selective attack along zones parallel to the basal plane of the ilmenite structure. After the initial phase of rapid dissolution, reaction rate declines and all extended period of concentration/time linearity follows. This decline in rate appears to relate to polymerisation and. transport of dissolved titanium within the porous solid. The addition of phosphate and fluoride to the system, has been shown to seriously affect the properties and transport of dissolved titanium. The effects of other interfering reagents such as additional titanium and iron were also considered. The observed behaviour of these ilmenites in dissolution, was related to the pattern of natural weathering identified in other ilmenite concentrates The structure and composition of a range of these materials was examined by X-ray diffraction, Electron microprobe and Mossbauer spectroscopy.</p>

Study on Influence of Silicate Morphology Based on pH Value

2012 ◽  
Vol 454 ◽  
pp. 324-328
Author(s):  
Yan He ◽  
Ya Jing Liu ◽  
Yong Lin Cao ◽  
Li Xia Zhou
Keyword(s):  
Silicic Acid ◽  
Ph Value ◽  
Colorimetric Method ◽  
Absorption Spectrometry ◽  
Degree Of Polymerization ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ph Values ◽  
The Stability

Infra-red absorption spectrometry, X-ray diffraction observations and characterization tests based on silicon molybdenum colorimetric method were used to investigate the optimal pH value controlling the stability of the silicic acid form. The experiment process was done by using sodium silicate as raw material. The results showed that the solution of silicate influenced the polymerization. The active silicic acid solution with a certain degree of polymerization was obtained by controlling the pH values.

Kummerite, Mn2+Fe3+Al(PO4)2(OH)2·8H2O, a new laueite-group mineral from the Hagendorf Süd pegmatite, Bavaria, with ordering of Al and Fe3+

2016 ◽  
Vol 80 (7) ◽  
pp. 1243-1254 ◽  
Author(s):  
I. E. Grey ◽  
E. Keck ◽  
W. G. Mumme ◽  
A. Pring ◽  
C. M. Macrae ◽  
...  
Keyword(s):  
Electron Microprobe ◽  
Empirical Formula ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Calculated Density ◽  
Group Mineral ◽  
X Ray ◽  
Cell Parameters ◽  
Octahedral Sites ◽  
Phosphate Mineral

AbstractKummerite, ideally Mn2+Fe3+A1(PO4)2(OH)2.8H2O, is a new secondary phosphate mineral belonging to the laueite group, from the Hagendorf-Süd pegmatite, Hagendorf, Oberpfalz, Bavaria, Germany. Kummerite occurs as sprays or rounded aggregates of very thin, typically deformed, amber yellow laths. Cleavage is good parallel to ﹛010﹜. The mineral is associated closely with green Zn- and Al-bearing beraunite needles. Other associated minerals are jahnsite-(CaMnMn) and Al-bearing frondelite. The calculated density of kummerite is 2.34 g cm 3. It is optically biaxial (-), α= 1.565(5), β = 1.600(5) and y = 1.630(5), with weak dispersion. Pleochroism is weak, with amber yellow tones. Electron microprobe analyses (average of 13 grains) with H2O and FeO/Fe2O3 calculated on structural grounds and normalized to 100%, gave Fe2O3 17.2, FeO 4.8, MnO 5.4, MgO 2.2, ZnO 0.5, Al2O3 9.8, P2O5 27.6, H2O 32.5, total 100 wt.%. The empirical formula, based on 3 metal apfu is (Mn2+0.37Mg0.27Zn0.03Fe2+0.33)Σ1.00(Fe3+1.06Al0. 94)Σ2.00PO4)1.91(OH)2.27(H2O)7.73. Kummerite is triclinic, P1̄, with the unit-cell parameters of a = 5.316(1) Å, b =10.620(3) Å , c = 7.118(1) Å, α = 107.33(3)°, β= 111.22(3)°, γ = 72.22(2)° and V= 348.4(2) Å3. The strongest lines in the powder X-ray diffraction pattern are [dobs in Å(I) (hkl)] 9.885 (100) (010); 6.476 (20) (001); 4.942 (30) (020); 3.988 (9) (̄110); 3.116 (18) (1̄20); 2.873 (11) (1̄21). Kummerite is isostructural with laueite, but differs in having Al and Fe3+ ordered into alternate octahedral sites in the 7.1 Å trans-connected octahedral chains.

Characterization and genesis of horizontal banding in Brazilian agate: an X-ray diffraction, thermogravimetric and electron microprobe study

2013 ◽  
Vol 77 (3) ◽  
pp. 227-248 ◽  
Author(s):  
T. Moxon ◽  
C. M. Petrone ◽  
S. J. B. Reed
Keyword(s):  
Amorphous Silica ◽  
Electron Microprobe ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wall Lining ◽  
Defect Site ◽  
Site Water ◽  
Stage Process ◽  
Upper Chamber

AbstractCharacterization of Brazilian agates containing a lower horizontally banded section and an upper chamber with bands parallel to the walls shows that these agates formed much later than the 135 Ma Paraná basalt host rock. Age differentiation between the two types of banding shows that the horizontal bands formed between 43 to 63 Ma ago with a final infill of wall-lining bands between 7 and 27 Ma later. The horizontal bands have a higher Al3+ concentration and a greater crystallite size than the wall-lining layers; they have a lower mogánite content and defect-site water content. The formation of these agates appears to be the result of a three-stage process. After the separate formation of horizontally banded and wall-lining agate, a silica infill seals the gap between the agate and the cavity wall. The detection of cristobalite in some specimens indicates that genesis of both the horizontally banded and wall-lining deposits in the Brazilian samples proceeds along an amorphous silica → opal-CT → opal-C → chalcedony pathway.

scholarly journals Quasi-Isostructural Co(II) and Ni(II) Complexes with Mefenamato Ligand: Synthesis, Characterization, and Biological Activity

Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3099 ◽  
Author(s):  
Michał Gacki ◽  
Karolina Kafarska ◽  
Anna Pietrzak ◽  
Izabela Korona-Głowniak ◽  
Wojciech M. Wolf
Keyword(s):  
Absorption Spectrometry ◽  
Hirshfeld Surface ◽  
Polymeric Chain ◽  
X Ray Diffraction ◽  
Intermolecular Hydrogen Bonds ◽  
X Ray ◽  
Gram Positive Bacteria ◽  
Flame Atomic Absorption ◽  
Intermolecular Contacts ◽  
Antioxidant And Antimicrobial Activity

Three metal complexes of mefenamato ligand 1 were synthesized: [Co2(mef)4(EtOH)2(H2O)4]: 2; [Co(mef)2(MeOH)4]∙2MeOH: 3; and [Ni(mef)2(MeOH)4]∙2MeOH: 4. Their compositions and properties were investigated by elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Crystal structures were determined by the single crystal X-ray diffraction technique. Additionally, their antioxidant and antimicrobial activity were established, thus proving good/moderate bioactivity against Gram-positive bacteria and yeasts. In the crystal structure of 2, an apical water molecule is shared between two adjacent cobalt(II) ions, resulting in the formation of a polymeric chain extending along the [100] direction. Meanwhile, structures 3 and 4 have strong intermolecular hydrogen bonds with diverse topologies that yield unique quasi-isostructural arrangements. The packing topology is reflected by the Hirshfeld surface analysis of intermolecular contacts.

Selenylation, Characterization and Cytotoxic Activity of Seleno-Astragalus Polysaccharide

2013 ◽  
Vol 411-414 ◽  
pp. 3146-3149 ◽  
Author(s):  
Yu Bin Ji ◽  
Fang Dong ◽  
Miao Yu
Keyword(s):  
Cytotoxic Activity ◽  
Human Breast Cancer ◽  
Human Breast ◽  
X Ray Diffraction ◽  
X Ray ◽  
Astragalus Polysaccharide ◽  
Series Of Experiments ◽  
Dose Dependent ◽  
Mcf 7

This paper investigated the selenylation, characterization and cytotoxic activity of seleno-Astragalus polysaccharide. Firstly, Se-APS was synthesized under reaction time at 8 h, reaction temperature at 80 °C, ratio of Na2SeO3 to APS at 1.0 g/g and water bath shaking rate at 40 r/min. Then, a series of experiments were designed to investigate the characterization and cytotoxicity of Se-APS. The result indicated that the characterization of Se-APS was significantly different from APS, except for X-ray diffraction. Additionally, MTT assay conformed that Se-APS could significantly inhibit the proliferation of human breast cancer MCF-7 cells in dose-dependent and time-dependent manners.

Electron Microprobe Analyses and X-Ray Diffraction Study of SrSi2

1966 ◽  
Vol 10 ◽  
pp. 409-421
Author(s):  
G. M. Faulring ◽  
E. S. Malizie
Keyword(s):  
Electron Microprobe ◽  
Polarized Light ◽  
Surface Preparation ◽  
Unit Cell ◽  
Intensity Data ◽  
Beam Size ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Probable Space

AbstractAlthough the phase SrSi2 has been previously recognized, it has been described only briefly in the literature.An alloy comprised of FeSi2, silicon, and the SrSi2 phase was examined on the electron microprobe. Optical and electron scanning images are correlated with X-ray scanning images for iron, silicon, calcium, and strontium. Quantitative microprobe analyses were made and corrected for absorption and the atomic number effect by several noncomputer methods. The corrections include as variables the X-ray intensities measured at several accelerating voltages. The effects of varying the electron beam size and accelerating potential are included. The results are compared to chemical analyses. The advantages of varying the accelerating voltage when correcting intensity data, increasing the beam size when surface preparation is a factor, and the importance of surface preparation at low accelerating voltages are discussed.An X-ray diffraction examination showed that the phase SrSi2 has a cubic unit cell with an a0 of 6.515 Å. There are four molecules per unit cell, and the most probable space group appears to be P213. The density was calculated as 3.45 (observed density >3.3).Metallographic observations with ordinary and polarized light and microhardness measurements are included.

X-ray Diffraction/Electron Microprobe Analysis of Surface Films Formed on Alloys During Hydrothermal Reaction with Geologic Materials

1984 ◽  
Vol 28 ◽  
pp. 367-375 ◽  
Author(s):  
R. G. Johnston ◽  
M. B. Strope ◽  
R. P. Anantatmula
Keyword(s):  
Electron Microprobe ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
Hydrothermal Reaction ◽  
Pressure Vessels ◽  
Surface Films ◽  
X Ray Diffraction ◽  
X Ray ◽  
Geologic Materials ◽  
Structure Phase

AbstractX-ray diffraction and electron microprobe analysis were used in combination to identify reaction phases that formed on the surfaces of low-carbon steel specimens reacted with a 75% basalt-25% bentonite mixture and anion-doped water in sealed pressure vessels at 100°C and 250°C. Reaction phases on specimen surfaces and in adhering geologic material were identified by conventional X-ray diffraction scans of entire specimens with intact reaction layers. Comparison of results from adhering geologic material and scans of selectively removed layers allowed establishment of approximate reaction gradients in the adhering packing material. Electron microprobe analysis of specimens in cross-section provided quantitative chemical analyses of adhering reaction phases, and identification of reaction layer composition gradients and thicknesses. Magnetite formed on the surface of specimens reacted at 250°C for 4 weeks. Iron-enriched clay was also observed on specimen surfaces and in the adjacent basalt-bentonite mixture. The 100°C experiments yielded surface films of a siderite-structure phase, (Fe,Ca,Mn)CO3, that were not observed in previous experiments with synthetic ground-water. Less extensive iron enrichment of the adjacent clays compared to that seen in the 250°C experiments was observed. The siderite-structure phase generally formed when no carbonate ion was present in the initial solution, implying dissolution of impurity calcite in the bentonite as the controlling factor in the reaction. The results demonstrate the utility of combining X-ray diffraction and electron microprobe analysis for characterization of reaction phases on alloys reacted with complex geologic materials.

scholarly journals Electrochemical deposition of coatings of highly entropic alloys from non-aqueous solutions

2016 ◽  
Vol 60 (1) ◽  
pp. 6-12 ◽  
Author(s):  
V. Jeníček ◽  
L. Diblíková ◽  
M. Bláhová
Keyword(s):  
Aqueous Solutions ◽  
Electrochemical Deposition ◽  
Absorption Spectrometry ◽  
New Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Electrochemical Coating ◽  
First Results ◽  
Combination Of Methods

Abstract The paper deals with electrochemical deposition of coatings of highly entropic alloys. These relatively new materials have been recently intensively studied. The paper describes the first results of electrochemical coating with highly entropic alloys by deposition from non-aqueous solutions. An electrochemical device was designed and coatings were deposited. The coatings were characterised with electronic microscopy scanning, atomic absorption spectrometry and X-ray diffraction methods and the combination of methods of thermic analysis of differential scanning calorimetry and thermogravimetry.

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