scholarly journals Hydrothermal and Metasomatic Kaolin Resource Estimation in the Quang Ninh area, Northeastern Vietnam

2021 ◽  
Vol 54 (2E) ◽  
pp. 176-185
Author(s):  
Khuong The Hung
Keyword(s):  
Mineral Resource ◽  
Statistical Methods ◽  
High Alumina ◽  
Chemical Analyses ◽  
Resource Estimation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ore Minerals ◽  
The One ◽  
Quang Ninh

In northeastern Vietnam, hydrothermal‐metasomatic kaolinite-pyrophyllite from the secondary quartzite origin has been found in many places, including Pin Ho, Ban Ngai, Khe Khoai, Pec Sec Leng, Tan Mai ore occurrences, etc. They are exploited together with pyrophyllite, alunite, and high‐alumina quartzite as a byproduct. There were 810 chemical and mineral samples in the Quang Ninh area collected to investigate hydrothermal‐metasomatic kaolin resources. The ore minerals consist of kaolin-group minerals (kaolinite, dickite), pyrophyllite, quartz with minor sericite, alunite, diaspora, etc. They were identified by X-ray diffraction, and microscope and scanning electron microscope coupled with energy-dispersive X-ray spectroscopy analyses. Chemical analyses of major oxides were carried out on clays and parent rock samples by X-ray fluorescence spectrometry. The similarity-analogy in ore geology and mineral resource estimation based on statistical methods are employed to estimate hydrothermal‐metasomatic kaolin resources from the Quang Ninh area in northeastern Vietnam. The mineral resource estimation based on statistical methods shows 2.21 million tons of kaolin obtained by the content of aluminum oxide over 28% of the Pec Sec Leng mine, accounting for 14.3% in total. The similarity-analogy in ore geology indicates 158.16 million tons of kaolinite-pyrophyllite ores, of which, 22.0 million tons are kaolin. These methods display that the Quang Ninh area contains mainly pyrophyllite rather than kaolin resources. Our study suggests that the Quang Ninh area can be considered as a potential pyrophyllite resource in northeastern Vietnam for future exploration. Furthermore, the one resource estimation based on similarity-analogy in ore geology method shows an overview of the prospect on kaolinite-pyrophyllite resources in the Quang Ninh area, northeastern Vietnam.

scholarly journals ZnOTe Compounds Grown by DC-Magnetron Co-Sputtering

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 570
Author(s):  
Olga Sánchez ◽  
Manuel Hernández-Vélez
Keyword(s):  
Molar Fraction ◽  
Variable Parameter ◽  
Point Of View ◽  
X Ray Diffraction ◽  
X Ray ◽  
Sample Series ◽  
Solid Phases ◽  
The One ◽  
High Bulk ◽  
Substrate Sample

ZnOTe compounds were grown by DC magnetron cosputtering from pure Tellurium (Te) and Zinc (Zn) cathodes in O2/Ar atmosphere. The applied power on the Zn target was constant equal to 100 W, while the one applied on the Te target took two values, i.e., 5 W and 10 W. Thus, two sample series were obtained in which the variable parameter was the distance from the Te targets to the substrate. Sample compositions were determined by Rutherford Backscattering Spectroscopy (RBS) experiments. Structural analysis was done using X-Ray diffraction (XRD) spectrometry and the growth of the hexagonal w-ZnO phase was identified in the XRD spectra. RBS results showed high bulk homogeneity of the samples forming ZnOTe alloys, with variable Te molar fraction (MF) ranging from 0.48–0.6% and from 1.9–3.1% for the sample series obtained at 5 W and 10 W, respectively. The results reflect great differences between the two sample series, particularly from the structural and optical point of view. These experiments point to the possibility of Te doping ZnO with the permanence of intrinsic defects, as well as the possibility of the formation of other Te solid phases when its content increases. The results and appreciable variations in the band gap transitions were detected from Photoluminescence (PL) measurements.

A Novel Hydroxyapatite Carrier for Enrichment of Hydrocarbon Degradation Bacteria

2007 ◽  
Vol 336-338 ◽  
pp. 1914-1917
Author(s):  
Lei Yang ◽  
Zhen Yi Zhang ◽  
Xiao Shan Ning ◽  
Guang He Li
Keyword(s):  
Activated Carbon ◽  
Sol Gel ◽  
Hydrocarbon Degradation ◽  
Potential Candidate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Bacterial Enrichment ◽  
Bet Method ◽  
The One ◽  
Scanning Electron

In this paper, a novel and highly efficient hydroxyapatite (HA) carrier for cultivating hydrocarbon degradation bacteria (HDB) is introduced. The HA particles synthesized through a sol-gel method and different heat treatments were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET method. The microbial amount and activities of HDB cultivated on HA carriers were quantitatively investigated in order to assess their enriching capabilities. The results showed that HA synthesized at 550°C and the one without calcination could enrich HDB 3 and 2 magnitude orders more than the activated carbon, respectively. Mechanisms of bacterial enrichment on HA and activated carbon were also studied, and it is believed that the high bioactivity and the surface morphology of HA were responsible for the efficient reproduction of HDB. It is concluded that HA is a potential candidate to replace the conventionally used activated carbon as a novel carrier applied in the filed of bioremediation for oil contaminated soil.

Discovery of Se-rich canfieldite, Ag8Sn(S,Se)6, from the Shuangjianzishan Ag–Pb–Zn deposit, NE China: A multimethodic chemical and structural study

2018 ◽  
Vol 83 (03) ◽  
pp. 419-426 ◽  
Author(s):  
Degao Zhai ◽  
Luca Bindi ◽  
Panagiotis C. Voudouris ◽  
Jiajun Liu ◽  
Stylianos F. Tombros ◽  
...  
Keyword(s):  
Site Occupancy ◽  
Integrated Approach ◽  
X Ray Diffraction ◽  
Ne China ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Ore Bodies ◽  
Vein Type ◽  
Ore Minerals

AbstractDuring a study of the ore minerals belonging to the recently discovered Shuangjianzishan Ag–Pb–Zn deposit in NE China, we have discovered exceptional selenium enrichment in canfieldite (up to 11.6 wt.% of Se). Incorporation of Se into canfieldite has been investigated by an integrated approach using field emission scanning electron microscopy, electron microprobe and single-crystal X-ray diffraction. Canfieldite has been identified as one of the dominant Ag-bearing ore minerals in the studied deposit, which occurs mostly in slate-hosted vein type Ag–Pb–Zn ore bodies. Selenium is either homogeneously or, remarkably, heterogeneously distributed in the different canfieldite fragments studied. Chemical variations of Se are mostly attributable to a series of retrograde reactions resulting in diverse decomposition and exsolution of primary phases during cooling, or alternatively, related to influxes of Se-rich fluids during the formation of canfieldite. To evaluate the effects of the Se-for-S substitution in the structure, a crystal of Se-rich canfieldite [Ag7.98Sn1.02(S4.19Se1.81)Σ6.00] was investigated. The unit-cell parameters are: a = 10.8145(8) Å and V = 1264.8(3) Å3. The structure was refined in the space group F$\bar{4}$3m to R1 = 0.0315 for 194 independent reflections, with 20 parameters. The crystal structure of Se-rich canfieldite was found to be topologically identical to that of pure canfieldite. If the short Ag–Ag contacts are ignored (due to the disorder), the two Ag atoms in the structure can be considered as three-fold (Ag1) and four-fold (Ag2) coordinated. Tin adopts a regular tetrahedral coordination. As in the case of Te-rich canfieldite, the refinement of the site-occupancy factor indicates that Se is disordered over the three anion positions.

The crystal structure of gatehouseite

2011 ◽  
Vol 75 (6) ◽  
pp. 2823-2832
Author(s):  
P. Elliott ◽  
A. Pring
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Three Dimensional ◽  
Direct Methods ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
X Ray ◽  
Manganese Phosphate ◽  
Phosphate Mineral ◽  
Unit Formula

AbstractThe crystal structure of the manganese phosphate mineral gatehouseite, ideally Mn52+(PO4)2(OH)4, space group P212121, a = 17.9733(18), b = 5.6916(11), c = 9.130(4) Å, V= 933.9(4) Å3, Z = 4, has been solved by direct methods and refined from single-crystal X-ray diffraction data (T = 293 K) to an R index of 3.76%. Gatehouseite is isostructural with arsenoclasite and with synthetic Mn52+(PO4)2(OH)4. The structure contains five octahedrally coordinated Mn sites, occupied by Mn plus very minor Mg with observed <Mn—O> distances from 2.163 to 2.239 Å. Two tetrahedrally coordinated P sites, occupied by P, Si and As, have <P—O> distances of 1.559 and 1.558 Å. The structure comprises two types of building unit. A strip of edge-sharing Mn(O,OH)6 octahedra, alternately one and two octahedra wide, extends along [010]. Chains of edge- and corner-shared Mn(O,OH)6 octahedra coupled by PO4 tetrahedra extend along [010]. By sharing octahedron and tetrahedron corners, these two units form a dense three-dimensional framework, which is further strengthened by weak hydrogen bonding. Chemical analyses by electron microprobe gave a unit formula of (Mn4.99Mg0.02)Σ5.01(P1.76Si0.07(As0.07)Σ2.03O8(OH)3.97.

Polysulfonylamine, CXXV [1]. Neue Komplexe von Disulfonylaminen mit Kronenethern - im voraus entworfen oder zufällig entdeckt / Polysulfonylamines, CXXV [1]. New Complexes of Disulfonylam ines with Crown Ethers - Preconceived or Discovered by Serendipity

2000 ◽  
Vol 55 (3-4) ◽  
pp. 299-316 ◽  
Author(s):  
Dagmar Henschel ◽  
Karna Wijaya ◽  
Oliver Moers ◽  
Armand Blaschette ◽  
Peter G. Jones
Keyword(s):  
Hydrogen Bonds ◽  
X Ray Diffraction ◽  
Ladder Structure ◽  
Triclinic Space Group ◽  
One Dimensional ◽  
X Ray ◽  
Bonding System ◽  
Supramolecular Aggregate ◽  
Guest Species ◽  
The One

Abstract In a study aim ed at the „deconstruction“ of the supramolecular aggregate 3(18C6) · 2HN( SO2Me)2 (1,18C6 = 18-crown-6), which is known to display a ladder structure with two isotactic [18C6 - Me SO2N(H)SO2Me···)∞ polymers forming the uprights and symmetrically N - H···O bonded 18C6 rings providing the rungs, the following crystalline complexes were isolated and (except for 2b) characterized by low-temperature X-ray diffraction: 18C6-ClN (SO2Me)2 (2a, triclinic, space group P1̅, Z = 2), 18C6-PhN (SO2Me)2 (2b), 18C6 -MeN(SO2Me)2 (3, monoclinic, P21/c, Z = 8), Bz18C6-HN(SO2Me)2 (4, Bz18C6 = benzo-18-crown-6, monoclinic, P21/n, Z = 4), 18C6-2 MeN (SO2Me)2 (5, triclinic, P1̅, Z = 1), 18C6-Me2SO- HN( SO2Me) (SO2Ph) (13, triclinic, P1̅, Z = 2), and 18C6-H2OMe2SO·2HN(SO2Me)2 (14, triclinic, P1̅, Z = 2). Each of the one-dimensional polymers 2a (syndiotactic), 3 (disyndiotactic) and 4 (isotactic) mimics a single upright of 1; in contrast to 1 and 2a, where the intra-catemer connectivity solely relies on S - Me ··· crow n and crown ··· O = S hydrogen bonds, this bonding system is reinforced in 3 by N -Me ··· crown and in 4 by N - H ··· crown hydrogen bonds. Complex 5 is monomeric and matches a fragment formally extruded from the catemer 3; moreover, 3 and 5 represent a rare case of two structurally characterized 18C6 complexes containing the same uncharged guest species in distinct molecular ratios. The surprising structure of the quaternary adduct 14 exhibits an [18C6 ··· MeSO2N(H)SO2Me ··· ]∞ chain, which can be regarded both as an isolated, though unmodified upright from the ladder 1 and, being syndiotactic, as a stereochemical analogue of 2a; the potentially rung-forming *NH functions in the chain are blocked by hydrogenbonded side chains of the type * N - H ··· water ··· sulfoxide ··· H - N (SO2Me)2. The ternary complex 13 consists of chains [18C6 ··· Me2SO ··· H - N (SO2Ph)SO2Me···]∞ and is not closely related to the other structures

scholarly journals Формирование и трансформация моноклинной и орторомбической фаз в реакторных порошках сверхвысокомолекулярного полиэтилена

2018 ◽  
Vol 60 (9) ◽  
pp. 1847
Author(s):  
М.В. Байдакова ◽  
П.В. Дороватовский ◽  
Я.В. Зубавичус ◽  
Е.М. Иванькова ◽  
С.С. Иванчев ◽  
...  
Keyword(s):  
Mechanical Stress ◽  
Room Temperature ◽  
Monoclinic Phase ◽  
Orthorhombic Phase ◽  
Ultrahigh Molecular Weight Polyethylene ◽  
Polymer Synthesis ◽  
X Ray Diffraction ◽  
Reactor Powder ◽  
X Ray ◽  
The One

AbstractUsing powerful synchrotron X-ray radiation of the beamline “Belok” operated by the National Research Center “Kurchatov Institute,” we perform X-ray diffraction (XRD) study of an intact, virgin (not subjected to any external mechanical loads) particle isolated from reactor powder of ultrahigh molecular weight polyethylene. Along with the peaks originating from the orthorhombic phase, we detect the peaks characteristic of the monoclinic phase that is stable only under mechanical stress, suggesting that the mechanical stress that leads to the formation of the monoclinic phase and persists at room temperature develops during the polymer synthesis. The monoclinic phase gradually disappears when the particle is heated stepwise in increments of 5 K, and its peaks become undetectable when the temperature reaches 340 K. We contrast the results obtained for the phase composition of the virgin particle to those for a tablet prepared by compaction of the same reactor powder at room temperature. XRD analyses of the tablet were performed on D2 Phaser (Bruker) instrument. The monoclinic phase that originates during the polymer synthesis and the one that forms in the tablet during compaction have different parameters. We discuss the mechanisms by which these two different monoclinic phases originate during the processes involved.

scholarly journals Time-resolved XRD experiments for a fine description of mechanisms induced during reactive sintering

2005 ◽  
Vol 37 (1) ◽  
pp. 27-34 ◽  
Author(s):  
S. Paris ◽  
E. Gaffet ◽  
D. Vrel ◽  
D. Thiaudiere ◽  
M. Gailhanou ◽  
...  
Keyword(s):  
Reactive Sintering ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Time Resolved ◽  
X Ray ◽  
Synthesis Conditions ◽  
Nanostructure Materials ◽  
Synchrotron Beam ◽  
The One

The control of Mechanically Activated Field Activated Pressure Assisted Synthesis hereafter called the MAFAPAS process is the main objective to be achieved for producing nanostructure materials with a controlled consolidation level. Consequently, it was essential to develop characterization tools "in situ" such as the Time Resolved X-ray Diffraction (TRXRD), with an X-ray synchrotron beam (H10, LURE Orsay) coupled to an infrared thermography to study simultaneously structural transformations and thermal evolutions. From the 2003 experiments, we took the opportunity to modify the sample-holder in order to reproduce the better synthesis conditions of the MAFAPAS process, but without the consolidation step. The versatility of the setup has been proved and could even be enhanced by the design of new sample holders. In addition, this work clearly shows that this equipment will allow, on the one hand, to make progress of the understanding of MAFAPAS mechanisms and, on the other hand, to adjust reaction parameters (mechanical activation and combustion synthesis) for producing many materials with an expected microstructure.

scholarly journals THE INFLUENCE OF THE META-STABLE TRIPLE POINT SOLUTION OF MONOCALCIUM PHOSPHATE MONOHYDRATE UPON THE CLAY SEPARATES OF TWO ONTARIO SOILS

1963 ◽  
Vol 43 (2) ◽  
pp. 260-267
Author(s):  
A. F. MacKenzie ◽  
C. A. Campbell
Keyword(s):  
Electron Microscope ◽  
Triple Point ◽  
Thermal Analyses ◽  
Chemical Analyses ◽  
Clay Loam ◽  
X Ray Diffraction ◽  
Monocalcium Phosphate ◽  
X Ray ◽  
Point Solution ◽  
Soil Clay

Samples of material less than 2 μ in diameter were obtained from the surface horizon of a Guelph loam and of a Haldimand clay loam. These samples were subjected to six successive treatments with the meta-stable triple point solution of monocalcium phosphate monohydrate (MTPS) to simulate the environment near a dissolving superphosphate granule. Samples of montmorillonite and illite standard clays were also included. The dissolution losses in per cent were: Guelph clay 59.5, Haldimand clay 40.4, montmorillonite 3.4, and illite 8.1. Total chemical analyses, X-ray diffraction techniques, differential thermal analyses and electron microscope observations were used to determine the nature of these losses. In the soil clay separates, vermiculite and interstratified montmorillonite were more susceptible to the action of MTPS than were the illite or halloysite clay minerals.

Chemical Synthesis and Properties of Layered Co1-yNiyO2-δOxides (0≤y≤1)

2000 ◽  
Vol 658 ◽  
Author(s):  
A. Manthiram ◽  
R. V. Chebiam ◽  
F. Prado
Keyword(s):  
Layer Structure ◽  
Magnetic Data ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Ni Content ◽  
Wet Chemical ◽  
Oxide Ions ◽  
Structure Layer

ABSTRACTLayered Co1-yNiyO2-δ oxides with 0≤y≤1 have been synthesized by chemically extracting lithium from LiNi1-yCoyO2 with NO2PF6 at ambient temperature. The samples have been characterized by X-ray diffraction, wet-chemical analyses, infrared spectroscopy, and magnetic susceptibility measurements. While NiO2-δ retains the initial O3 (CdCl2 structure) layer structure of LiNiO2, CoO2-δ consists of a mixture of P3 and O1 (CdI2 structure) phases that are formed by a sliding of the oxide ions in the initial O3 structure. CoO2-δ and NiO2-δ have oxygen contents of, respectively, 1.67 and 1.95 and the oxygen content increases with increasing Ni content, y, in Co1-yNiyO2-δ. While CoO2-δ exhibits metallic conductivity as revealed by theabsence of absorption bands in the infrared spectrum, NiO2-δ exhibits semiconducting behavior due to a completely filled t2g band. Magnetic data reveal a transition from antiferromagnetic to ferromagnetic correlations as the Ni content in Co1-yNiyO2-δ increases.

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