scholarly journals Effect of Temperature, Time, and Cooling Rate on the Mineralogy, Morphology, and Reducibility of Iron Ore Sinter Analogues

JOM ◽  
2020 ◽  
Vol 73 (1) ◽  
pp. 345-355
Author(s):  
Tobin Harvey ◽  
Mark I. Pownceby ◽  
Jeff Chen ◽  
Nathan A. S. Webster ◽  
Thi Bang Tuyen Nguyen ◽  
...  
Keyword(s):  
Light Microscopy ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Reflected Light ◽  
Iron Ore Sinter ◽  
Thermo Gravimetric Analyzer ◽  
Micro Analysis ◽  
Temperature Time

AbstractAnalogue sinter tablets were produced at temperatures between 1250°C and 1320°C, with a range of hold times and cooling rates. Platy silico-ferrite of calcium and aluminum (SFCA) morphology was identified in samples produced at 1250°C using reflected light microscopy; however, quantitative x-ray diffraction (XRD) identified the presence of the SFCA phase, with no SFCA-I detected. This proves that the platy SFCA morphology common in analysis by reflected light microscopy cannot be attributed to the SFCA-I mineral without further analysis. Micro-XRD and electron probe micro-analysis (EPMA) were carried out on an area of platy SFCA confirming this result. The sinter analogue tablets were reduced in a 30% CO, 70% N2 gas mixture at 900°C in a tube furnace thermo-gravimetric analyzer. The degree of reduction of the tablets in this study was found to be controlled by the porosity of the samples, rather than by the morphology or mineralogy of the bonding phase.

Adsorption Characteristics of Modified MiL-101(Cr) for Gas (Mainly CH4) Storage Applications

2015 ◽  
Author(s):  
How Wei Benjamin Teo ◽  
Anutosh Chakraborty ◽  
Kim Tiow Ooi
Keyword(s):  
Natural Gas ◽  
X Ray Diffraction ◽  
Uptake Capacity ◽  
N2 Adsorption ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Thermo Gravimetric Analyzer ◽  
Metal Organic ◽  
Ch4 Uptake

As promising material for gas storage applications, MIL-101(Cr) can further be modified by doping with alkali metal (Li+, Na+, K+) ions. However, the doping concentration should be optimized below 10% to improve the methane adsorption. This article presents (i) the synthesis of MIL-101 (Cr) Metal Organic Frameworks, (ii) the characterization of the proposed doped adsorbent materials by X-ray Diffraction, Scanning Electron Microscopy, N2 Adsorption, Thermo-Gravimetric Analyzer, and (iii) the measurements of methane uptakes for the temperatures ranging from 125 K to 303 K and pressures up to 10 bar. It is found that the Na+ doped MIL-101(Cr) exhibits CH4 uptake capacity of (i) 295 cm3/cm3 at 10 bar and 160 K and (ii) 95 cm3/cm3 at 10 bar at 298 K. This information is important to design adsorbed natural gas (ANG) storage tank under ANG-LNG (liquefied natural gas) coupling conditions.

Effect of MgO and NH4OH on Formation of 5Mg(OH)2·MgSO4·3H2O Whiskers

2012 ◽  
Vol 512-515 ◽  
pp. 91-94 ◽  
Author(s):  
Ri Yu ◽  
Jae Hwan Pee ◽  
Hyung Tae Kim ◽  
Kyung Ja Kim ◽  
Young Woong Kim ◽  
...  
Keyword(s):  
Molar Ratio ◽  
X Ray Diffraction ◽  
High Quality ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Practical Applications ◽  
Thermo Gravimetric Analyzer ◽  
High Concentrations ◽  
Sulfate Hydrate ◽  
Scanning Electron

The Magnesium hydroxide sulfate hydrate whiskers (5Mg(OH)2.MgSO4.3H2O, abbreviated 513MHSH) have attracted much attention due to its practical applications as filler and reinforcement. However, it is difficult to produce high quality MHSH because plate-like Mg(OH)2 impurities were formed in high concentrations of OH- and interaction between Mg2+ and OH-. In this work, to reduce formation Mg(OH)2, molar ratio ofSuperscript text magnesium oxide (MgO) and magnesium sulfate (MgSO4.7H2O) were controlled. As a result, when low concentration of SO42-, MHSH whiskers co-existed with hexagonal plate Mg(OH)2. The molar ratio of MgSO4.7H2O/MgO was high, uniform MHSH whiskers were formed without Mg(OH)2. In addition, appropriate amount of NH4OH has affected formation of high quality MHSH. Their morphologies and structures were determined by powder X-ray diffraction (XRD) scanning electron microscopy (SEM) and thermo-gravimetric analyzer (TGA)

scholarly journals Preparation of Polyimide @ Polypyrrole/Palladium Hollow Composites with Applications in Catalysis

2021 ◽  
pp. X
Author(s):  
Xue Fang ◽  
Guiming SU ◽  
Meihui SONG ◽  
Haijian JIANG ◽  
Xianghong CUI ◽  
...  
Keyword(s):  
Pd Nanoparticles ◽  
Catalytic Performance ◽  
Reducing Agent ◽  
X Ray Diffraction ◽  
Amino Groups ◽  
Polystyrene Nanoparticles ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Thermo Gravimetric Analyzer ◽  
Template Methods

Polyimide based hollow composites were successfully prepared by combining the situ and template methods together. Firstly, the complete words (PPy) shell was covered on the surface of polystyrene nanoparticles, then the polyamide acid and PdCl2 were covered on the surface of the materials after the calcination. Finally, PI@ PPy/Pd hollow composites were obtained by a chemical process. The structure and composition of composites were characterized by scanning electron microscopy X-ray diffraction, thermo gravimetric analyzer and differential scanning calorimeter, respectively. Palladium (Pd) nanoparticles were densely and uniformly anchored on the surface of PPy shell due to the coordination interaction between amino groups on PPy backbone and Pd2+ ions. They are ideal candidates as nanoreactors for heterogeneous catalysis due to their special structure. The catalytic performance of PI@ PPy/Pd hollow composites were studied by the reduction of NaBH4 as a reducing agent. The catalytic performance of composites was characterized by ultraviolet and visible spectrophotometer. The PI@PPy/Pd composites showed excellent catalytic performance in the reduction of methylene blue with sodium borohydride as reducing agent. The dye completely turned colorless as seen within 2.0 minutes.

scholarly journals Petrochemical Features of Manganese Nodules in Madaka (Sheet 142) SE and Part of Kwana - Bala (Sheet 142) NE, Nigeria

2021 ◽  
pp. 52-59
Author(s):  
Akintola Ojo Adeoye ◽  
Najime Tavershima ◽  
Danladi Bello Abubakar ◽  
Ogunleye Paul Olusegun ◽  
Abubakar Ismail Yusuf
Keyword(s):  
Light Microscopy ◽  
Electron Probe ◽  
Manganese Nodule ◽  
Chemical Study ◽  
Electron Probe Micro Analysis ◽  
Manganese Nodules ◽  
Future Time ◽  
X Ray ◽  
Reflected Light ◽  
Micro Analysis

Manganese nodule occurs in Madaka (Sheet 142) SE and part of Kwana - Bala (Sheet 142) NE, Nigeria. Four (4) samples of manganese nodules were analyzed petrochemical using X-ray diffractometry (XRD), reflected light microscopy, Electron probe micro analysis (EPMA), Atomic absorption spectrophotometer (AAS). XRD reveals sphalerite, manganates and ilmenite as major minerals in the nodules. Accessory minerals are siderite and rutile. Chemical study of the manganese nodules from Madaka and Kwana - Bala reveals that Mn-, Fe-, Co-, Ni-, and Cu-, minerals (including native elements and sulfides) commonly occur in the samples. Also, the results indicate that increased in Mn relative to the manganite content (10AO- plus 7AO), led to increase in Ni and Cu recovery. However, slightly greater amounts by weight of Ni and Cu were dissolved from the manganites than from Mn. This followed from the much higher Ni and Cu contents of manganites relative to Mn. The exploration for Ni and Cu from nodules on assay criterion was inadequate; the sphalerite Mn02 phase structure would also be a necessary criterion. It was suggested that nodules could be processed upon beneficiation for Ni and Cu contents for a future time relative to the original processing. It was thus proposed that Ni and Cu could be produced from manganese nodules in the study area.

Fabrication and characterization of electro-active cellulose films regenerated by using 1-butyl-3-methylimidazolium chloride ionic liquid

2013 ◽  
Vol 227 (12) ◽  
pp. 2665-2670 ◽  
Author(s):  
Ki-Baek Kim ◽  
Jaehwan Kim
Keyword(s):  
Ionic Liquid ◽  
Regenerated Cellulose ◽  
Cellulose Solution ◽  
Cellulose Film ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
X Ray ◽  
Thermo Gravimetric Analyzer ◽  
Regenerated Cellulose Film

This article reports dissolution, regeneration, and characterization of cellulose using an ionic liquid, namely 1-butyl-3-methylimidazolium chloride (BMIMCl). During dissolving process, BMIMCl takes much less time to dissolve cellulose with high degree of polymerization (DP = 4500) than other solvent system, lithium chloride/ N,N-dimethylacetamide (LiCl/DMAc). Regenerated cellulose film from BMIMCl–cellulose solution is characterized by viscosity, thermo gravimetric analyzer, X-ray diffraction, pull test, and transmittance test. Compared with LiCl/DMAc–cellulose, BMIMCl–cellulose solution has lower viscosity and its film has lower Young's modulus and yield strength. From thermo gravimetric analyzer and X-ray diffraction experiment, BMIMCl–cellulose film has impurity and X-ray diffraction pattern similar with those of LiCl/DMAc–cellulose film. BMIMCl–cellulose film exhibits higher transmittance. The ionic liquid recovery test verifies that BMIMCl is highly recoverable with 99%, which proves that BMIMCl is a green solvent. Through the bending displacement test, the BMIMCl–cellulose film shows a good actuation behavior of electro-active paper.

Effect of Temperature on Fe3O4 Magnetic Nanoparticles Prepared by Coprecipitation Method

2014 ◽  
Vol 900 ◽  
pp. 172-176 ◽  
Author(s):  
Ji Mei Niu ◽  
Zhi Gang Zheng
Keyword(s):  
Magnetic Nanoparticles ◽  
Coprecipitation Method ◽  
Effect Of Temperature ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Magnetic Carriers ◽  
Average Grain Size ◽  
Or Gene ◽  
Block Temperature

The Fe3O4 magnetic nanoparticles obtained by the aqueous coprecipitation method are characterized systematically using scanning electron microscope, X-ray diffraction and vibrating sample magnetometer. These magnetic nanoparticles are spheric, dispersive, and have average grain size of 50 nm. The size and magnetic properties of Fe3O4 nanoparticles can be tuned by the reaction temperature. All samples exhibit high saturation magnetization (Ms=53.4 emu·g-1) and superparamagnetic behavior with a block temperature (TB) of 215K. These properties make such Fe3O4 magnetic nanoparticles worthy candidates for the magnetic carriers of targeted-drug or gene therapy in future.

Dalnegroite, Tl5–xPb2x(As,Sb)2l–xS34, a new thallium sulphosalt from Lengenbach quarry, Binntal, Switzerland

2009 ◽  
Vol 73 (6) ◽  
pp. 1027-1032 ◽  
Author(s):  
F. Nestola ◽  
A. Guastoni ◽  
L. Bindi ◽  
L. Secco
Keyword(s):  
Polarized Light ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Elemental Concentrations ◽  
Reflected Light ◽  
Mohs Hardness ◽  
The Mean ◽  
The University ◽  
Probable Space

AbstractDalnegroite, ideally Tl4Pb2(As12Sb8)Σ20S34, is a new mineral from Lengenbach, Binntal, Switzerland. It occurs as anhedral to subhedral grains up to 200 μm across, closely associated with realgar, pyrite, Sb-rich seligmanite in a gangue of dolomite. Dalnegroite is opaque with a submetallic lustre and shows a brownish-red streak. It is brittle; the Vickers hardness (VHN25) is 87 kg mm-2(range: 69—101) (Mohs hardness ∼3—3½). In reflected light, dalnegroite is highly bireflectant and weakly pleochroic, from white to a slightly greenish-grey. In cross-polarized light, it is highly anisotropic with bluish to green rotation tints and red internal reflections.According to chemical and X-ray diffraction data, dalnegroite appears to be isotypic with chabournéite, Tl5-xPb2x(Sb,As)21-xS34. It is triclinic, probable space groupP1, witha= 16.217(7) Å,b= 42.544(9) Å,c= 8.557(4) Å, α = 95.72(4)°, β = 90.25(4)°, γ = 96.78(4)°,V= 5832(4) Å3,Z= 4.The nine strongest powder-diffraction lines [d(Å) (I/I0) (hkl)] are: 3.927 (100) (10 0); 3.775 (45) (22); 3.685 (45) (60); 3.620 (50) (440); 3.124 (50) (2); 2.929 (60) (42); 2.850 (70) (42); 2.579 (45) (02); 2.097 (60) (024). The mean of 11 electron microprobe analyses gave elemental concentrations as follows: Pb 10.09(1) wt.%, Tl 20.36(1), Sb 23.95(1), As 21.33(8), S 26.16(8), totalling 101.95 wt.%, corresponding to Tl4.15Pb2.03(As11.86Sb8.20)S34. The new mineral is named for Alberto Dal Negro, Professor in Mineralogy and Crystallography at the University of Padova since 1976.

AIN/GaN and AIGaN/GaN Heterostructures Grown by HVPE on SiC Substrates

1997 ◽  
Vol 482 ◽  
Author(s):  
Yu. V. Melnik ◽  
A. E. Nikolaev ◽  
S. I. Stepanov ◽  
A. S. Zubrilov ◽  
I. P. Nikitina ◽  
...  
Keyword(s):  
Growth Rate ◽  
Electron Beam ◽  
Vapor Phase ◽  
Electron Spectroscopy ◽  
Auger Electron ◽  
Hydride Vapor Phase Epitaxy ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Micro Analysis

AbstractGaN, AIN and AIGaN layers were grown by hydride vapor phase epitaxy. 6H-SiC wafers were used as substrates. Properties of AIN/GaN and AIGaN/GaN structures were investigated. AIGaN growth rate was about 1 μm/min. The thickness of the AIGaN layers ranged from 0.5 to 5 μm. The AIN concentration in AIGaN layers was varied from 9 to 67 mol. %. Samples were characterised by electron beam micro analysis, Auger electron spectroscopy, X-ray diffraction and cathodoluminescence.Electrical measurements performed on AIGaN/GaN/SiC samples indicated that undoped AIGaN layers are conducting at least up to 50 mol. % of AIN.

Hrabákite, Ni9PbSbS8, a new member of the hauchecornite group from Příbram, Czech Republic

2021 ◽  
pp. 1-8
Author(s):  
Jiří Sejkora ◽  
Pavel Škácha ◽  
Jakub Plášil ◽  
Zdeněk Dolníček ◽  
Jana Ulmanová
Keyword(s):  
Czech Republic ◽  
Diffraction Data ◽  
New Mineral ◽  
X Ray Diffraction ◽  
Calculated Density ◽  
X Ray ◽  
Reflected Light ◽  
Mohs Hardness ◽  
Cation Sites ◽  
The Ideal

Abstract The new mineral hrabákite (IMA2020-034) was found in siderite–sphalerite gangue with minor dolomite–ankerite at the dump of shaft No. 9, one of the mines in the abandoned Příbram uranium and base-metal district, central Bohemia, Czech Republic. Hrabákite is associated with Pb-rich tučekite, Hg-rich silver, stephanite, nickeline, millerite, gersdorffite, sphalerite and galena. The new mineral occurs as rare prismatic crystals up to 120 μm in size and allotriomorphic grains. Hrabákite is grey with a brownish tint. Mohs hardness is ca. 5–6; the calculated density is 6.37 g.cm–3. In reflected light, hrabákite is grey with a brown hue. Bireflectance is weak and pleochroism was not observed. Anisotropy under crossed polars is very weak (brownish tints) to absent. Internal reflections were not observed. Reflectance values of hrabákite in air (Rmin–Rmax, %) are: 39.6–42.5 at 470 nm, 45.0–47.5 at 546 nm, 46.9–49.2 at 589 nm and 48.9–51.2 at 650 nm). The empirical formula for hrabákite, based on electron-microprobe analyses (n = 11), is (Ni8.91Co0.09Fe0.03)9.03(Pb0.94Hg0.04)0.98(Sb0.91As0.08)0.99S7.99. The ideal formula is Ni9PbSbS8, which requires Ni 47.44, Pb 18.60, Sb 10.93 and S 23.03, total of 100.00 wt.%. Hrabákite is tetragonal, P4/mmm, a = 7.3085(4), c = 5.3969(3) Å, with V = 288.27(3) Å3 and Z = 1. The strongest reflections of the calculated powder X-ray diffraction pattern [d, Å (I)(hkl)] are: 3.6543(57)(200); 3.2685(68)(210); 2.7957(100)(211); 2.3920(87)(112); 2.3112(78)(310); 1.8663(74)(222); and 1.8083(71)(302). According to the single-crystal X-ray diffraction data (Rint = 0.0218), the unit cell of hrabákite is undoubtedly similar to the cell reported for tučekite. The structure contains four metal cation sites, two Sb (Sb1 dominated by Pb2+) and two Ni (with minor Co2+ content) sites. The close similarity in metrics between hrabákite and tučekite is due to similar bond lengths of Pb–S and Sb–S pairs. Hrabákite is named after Josef Hrabák, the former professor of the Příbram Mining College.

Immobilization of K7PW11O39 on ZrO2 Nanofiber: Ultra-deep Desulfurization Based in Extraction Catalytic Oxidation Desulfurization System

2021 ◽  
Vol 72 (3) ◽  
pp. 89-101
Author(s):  
Guowei Zeng ◽  
Guihong Wu ◽  
Zhihui Wang ◽  
Xiaonan Li ◽  
Jie Yang ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Catalytic Mechanism ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Thermo Gravimetric ◽  
Transmission Electron ◽  
Deep Desulfurization ◽  
Thermo Gravimetric Analyzer ◽  
Ft Ir ◽  
Model Oil

In this work, K7PW11O39 (abbreviated as PW11) was immobilized on ZrO2 nanofibers and used as an efficient recyclable catalyst in extraction catalytic oxidation desulfurization system (ECODS).The 500 ppm DBT model oil(5mL) can desulphurize completely within 20 min with the catalytic conditions of 50��, 0.010 g 50 wt%- CTAB�C PW11�CZrO2 nanofibers and O/S molar ratio H2O2/DBT molar ratio�� was 2:1. The synthesized catalyst was characterized by Fourier transform infrared spectroscopy (FT-IR), powder X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and thermo gravimetric analyzer (TGA). The results indicated the PW11�CZrO2 nanofibers were synthesized successfully and the possible catalytic mechanism is also revealed.

Sign in / Sign up

Export Citation Format

Share Document