scholarly journals Characterisation of fly ashes from 4th Thermal Power Station of Ulaanbaatar city and its applicability for a zeolite synthesis

2014 ◽  
Vol 12 ◽  
pp. 16-19
Author(s):  
J Temuujin ◽  
A Minjigmaa ◽  
B Davaabal ◽  
Z Ochirbat
Keyword(s):  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Thermal Power Station ◽  
Thermal Power ◽  
Particle Diameter ◽  
Area Measurement ◽  
Power Station ◽  
X Ray

Fly ash from 4th thermal power station of Ulaanbaatar city have been characterised by x-ray fluorescence (XRF), x-ray diffractometry (XRD), particle size analyzer, specific surface area measurement (BET) and scanning electron microscope (SEM) observation. It was found that fly ash from Baganuur coal contains over 15 wt.% of calcium oxide (CaO) and could be assigned as class C fly ash, according to the International classification. Specific surface area of this fly ash was 2.75 m2/g and mean particle diameter was 59.5 μm. Zeolitic compounds were synthesised by using mixture of this fly ash and a transition aluminium oxide under hydrothermal treatment at 100, 150 and 200°C temperatures for a different duration. Various zeolitic compounds including Na-faujasite and sodium aluminosilicate were synthesised as reaction products.DOI: http://dx.doi.org/10.5564/mjc.v12i0.164 Mongolian Journal of Chemistry Vol.12 2011: 16-19 

The Physical and Chemical Properties of Fly Ash fom Municipal Solid Wastes Incineration

2011 ◽  
Vol 194-196 ◽  
pp. 2065-2071
Author(s):  
Man Tong Jin ◽  
Cai Ju Huang ◽  
Zan Fang Jin
Keyword(s):  
Heavy Metals ◽  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Particle Diameter ◽  
Average Particle ◽  
Municipal Solid Wastes ◽  
Mswi Fly Ash ◽  
Treatment Technology

Fly ash from the municipal solid waste incineration (MSWI) which contains a small amount of heavy metals becomes a threat to human health and other living organisms once emitted into the environment, and has to be treated before disposal. This study focuses on the characteristics of the MSWI fly ash, which involve mineral composing, granularity distributing, specific surface area, pore diameter and pore volume of fly ash, leaching toxicity and chemical species of heavy metals. The experiment results confirm that the fly ashes are mainly composed of sylvite, halite, portlandite and calcium sulfate hydrate, with the the average particle diameter of 15.082 μm and the specific surface area of 4.290 m2/g, and the heavy metals such as Pb, Cu, Cr in the MSWI fly ash are mobile except Hg. This research provides critical information for appropriate MSWI fly ash treatment technology.

scholarly journals Fe-Doped g-C3N4: High-Performance Photocatalysts in Rhodamine B Decomposition

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 1963
Author(s):  
Minh Nguyen Van ◽  
Oanh Mai ◽  
Chung Pham Do ◽  
Hang Lam Thi ◽  
Cuong Pham Manh ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Recombination Rate ◽  
High Performance ◽  
Area Measurement ◽  
Bet Surface Area ◽  
Xenon Lamp ◽  
Electron Hole ◽  
X Ray

Herein, Fe-doped C3N4 high-performance photocatalysts, synthesized by a facile and cost effective heat stirring method, were investigated systematically using powder X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET) surface area measurement, X-ray photoelectron (XPS), UV–Vis diffusion reflectance (DRS) and photoluminescence (PL) spectroscopy. The results showed that Fe ions incorporated into a g-C3N4 nanosheet in both +3 and +2 oxidation states and in interstitial configuration. Absorption edge shifted slightly toward the red light along with an increase of absorbance in the wavelength range of 430–570 nm. Specific surface area increased with the incorporation of Fe into g-C3N4 lattice, reaching the highest value at the sample doped with 7 mol% Fe (FeCN7). A sharp decrease in PL intensity with increasing Fe content is an indirect evidence showing that electron-hole pair recombination rate decreased. Interestingly, Fe-doped g-C3N4 nanosheets present a superior photocatalytic activity compared to pure g-C3N4 in decomposing RhB solution. FeCN7 sample exhibits the highest photocatalytic efficiency, decomposing almost completely RhB 10 ppm solution after 30 min of xenon lamp illumination with a reaction rate approximately ten times greater than that of pure g-C3N4 nanosheet. This is in an agreement with the BET measurement and photoluminescence result which shows that FeCN7 possesses the largest specific surface area and low electron-hole recombination rate. The mechanism of photocatalytic enhancement is mainly explained through the charge transfer processes related to Fe2+/Fe3+ impurity in g-C3N4 crystal lattice.

Preparation and Characterization of Flowerlike Nickel Oxide

2011 ◽  
Vol 121-126 ◽  
pp. 1044-1048
Author(s):  
Chang Yu Li ◽  
Shou Xin Liu ◽  
Li Li Liu
Keyword(s):  
Nickel Oxide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Area Measurement ◽  
Simple Liquid ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Area Measurement

Flowerlike nickel oxide was synthesized by a simple liquid-phase process to obtain the hydroxide precursor and then calcined to form the nickel oxide. The precursor and the nickel oxide were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) , the scanning electron microscope(SEM) and Brunauer–Emmett–Teller-specific surface area measurement. The results indicated α-Nickel hydroxide was transferred to NiO with a cubic crystalline structure after being calcined at 450 °C; the NiO still kept the morphology of the precursors and the specific surface area of the NiO was 125.2m2/g.

A Novel Method for the Preparation of Nano-Sized Nickle Powders

2012 ◽  
Vol 512-515 ◽  
pp. 1849-1853 ◽  
Author(s):  
Zhao Han ◽  
Hong Min Zhu
Keyword(s):  
Electron Microscopy ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Chemical Reduction ◽  
Particle Diameter ◽  
Area Measurement ◽  
Average Particle ◽  
Transmission Electron ◽  
20 Nm

Nano-sized nickel powders were prepared through a wet chemical reduction, of NiCl2 by sodium in liquid ammonia at -45 °C, and a subsequent heat-treatment in vacuum at 300 °C. The prepared product was systematically characterized by X-ray diffraction (XRD), scan electron microscopy (SEM), transmission electron microscopy (TEM), and BET specific surface area measurement. The results show that the product was composed of nano-sized nickel particles, with average particle diameter of about 20 nm, and specific surface area of about 30 m2g-1. The possible formation mechanism of the nano-sized nickel powder was also discussed briefly.

scholarly journals Structural and Morphological Quantitative 3D Characterisation of Ammonium Nitrate Prills by X-Ray Computed Tomography

Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1230
Author(s):  
Fabien Léonard ◽  
Zhen Zhang ◽  
Holger Krebs ◽  
Giovanni Bruno
Keyword(s):  
Computed Tomography ◽  
Specific Surface ◽  
Ammonium Nitrate ◽  
Surface Area ◽  
Specific Surface Area ◽  
Volume Fraction ◽  
Fuel Oil ◽  
X Ray ◽  
Oil Retention ◽  
X Ray Computed

The mixture of ammonium nitrate (AN) prills and fuel oil (FO), usually referred to as ANFO, is extensively used in the mining industry as a bulk explosive. One of the major performance predictors of ANFO mixtures is the fuel oil retention, which is itself governed by the complex pore structure of the AN prills. In this study, we present how X-ray computed tomography (XCT), and the associated advanced data processing workflow, can be used to fully characterise the structure and morphology of AN prills. We show that structural parameters such as volume fraction of the different phases and morphological parameters such as specific surface area and shape factor can be reliably extracted from the XCT data, and that there is a good agreement with the measured oil retention values. Importantly, oil retention measurements (qualifying the efficiency of ANFO as explosives) correlate well with the specific surface area determined by XCT. XCT can therefore be employed non-destructively; it can accurately evaluate and characterise porosity in ammonium nitrate prills, and even predict their efficiency.

scholarly journals Study on Adsorption Mechanism and Failure Characteristics of CO2 Adsorption by Potassium-Based Adsorbents with Different Supports

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2424 ◽  
Author(s):  
Bao-guo Fan ◽  
Li Jia ◽  
Yan-lin Wang ◽  
Rui Zhao ◽  
Xue-song Mei ◽  
...  
Keyword(s):  
Fly Ash ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Reaction Temperature ◽  
Adsorption Mechanism ◽  
Co2 Adsorption ◽  
Carbonation Reaction ◽  
Failure Characteristics ◽  
Boiler Fly Ash

In order to obtain the adsorption mechanism and failure characteristics of CO2 adsorption by potassium-based adsorbents with different supports, five types of supports (circulating fluidized bed boiler fly ash, pulverized coal boiler fly ash, activated carbon, molecular sieve, and alumina) and three kinds of adsorbents under the modified conditions of K2CO3 theoretical loading (10%, 30%, and 50%) were studied. The effect of the reaction temperature (50 °C, 60 °C, 70 °C, 80 °C, and 90 °C) and CO2 concentration (5%, 7.5%, 10%, 12.5%, and 15%) on the adsorption of CO2 by the adsorbent after loading and the effect of flue gas composition on the failure characteristics of adsorbents were obtained. At the same time, the microscopic characteristics of the adsorbents before and after loading and the reaction were studied by using a specific surface area and porosity analyzer as well as a scanning electron microscope and X-ray diffractometer. Combining its reaction and adsorption kinetics process, the mechanism of influence was explored. The results show that the optimal theoretical loading of the five adsorbents is 30% and the reaction temperature of 70 °C and the concentration of 12.5% CO2 are the best reaction conditions. The actual loading and CO2 adsorption performance of the K2CO3/AC adsorbent are the best while the K2CO3/Al2O3 adsorbent is the worst. During the carbonation reaction of the adsorbent, the cumulative pore volume plays a more important role in the adsorption process than the specific surface area. As the reaction temperature increases, the internal diffusion resistance increases remarkably. K2CO3/AC has the lowest activation energy and the carbonation reaction is the easiest to carry out. SO2 and HCl react with K2CO3 to produce new substances, which leads to the gradual failure of the adsorbents and K2CO3/AC has the best cycle failure performance.

scholarly journals Preparation of Zirconia Nanofibers by Electrospinning and Calcination with Zirconium Acetylacetonate as Precursor

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1067 ◽  
Author(s):  
Vyacheslav V. Rodaev ◽  
Svetlana S. Razlivalova ◽  
Andrey O. Zhigachev ◽  
Vladimir M. Vasyukov ◽  
Yuri I. Golovin
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Heterogeneous Catalysts ◽  
Tetragonal Zirconia ◽  
Nitrogen Adsorption ◽  
Average Diameter ◽  
High Specific Surface Area ◽  
X Ray ◽  
Adsorption Analysis

For the first time, zirconia nanofibers with an average diameter of about 75 nm have been fabricated by calcination of electrospun zirconium acetylacetonate/polyacrylonitrile fibers in the range of 500–1100 °C. Composite and ceramic filaments have been characterized by scanning electron microscopy, thermogravimetric analysis, nitrogen adsorption analysis, energy-dispersive X-ray spectroscopy, and X-ray diffractometry. The stages of the transition of zirconium acetylacetonate to zirconia have been revealed. It has been found out that a rise in calcination temperature from 500 to 1100 °C induces transformation of mesoporous tetragonal zirconia nanofibers with a high specific surface area (102.3 m2/g) to non-porous monoclinic zirconia nanofibers of almost the same diameter with a low value of specific surface area (8.3 m2/g). The tetragonal zirconia nanofibers with high specific surface area prepared at 500 °C can be considered, for instance, as promising supports for heterogeneous catalysts, enhancing their activity.

Study of Heating Effect on Specific Surface Area, and Changing Optical Properties of ZnO Nanocrystals

2011 ◽  
Vol 403-408 ◽  
pp. 1205-1210
Author(s):  
Jaleh Babak ◽  
Ashrafi Ghazaleh ◽  
Gholami Nasim ◽  
Azizian Saeid ◽  
Golbedaghi Reza ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Energy Gap ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Zno Nanocrystals ◽  
Transmission Electron ◽  
Zno Nanocrystal

In this work ZnO nanocrystal powders have been synthesized by using Zinc acetate dehydrate as a precursor and sol-gel method. Then the products have been annealed at temperature of 200-1050°C, for 2 hours. The powders were characterized using X-ray diffraction (XRD), UV-vis absorption and photoluminescence (PL) spectroscopy. The morphology of refrence ZnO nanoparticles have been studied using Transmission Electron Microscope (TEM). During the annealing process, increase in nanocrystal size, defects and energy gap quantitative, and decrease in specific surface area have been observed.

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