Alkali activation of different type of ash as a production of combustion process

Presented study deals with the final structure and radiological properties of different fly ash-based geopolymers. lignite fly-ash (lignite Kolubara - Serbia) and wood fly ash were obtained in combustion process together with commercial fly ash. Synthesis of the geopolymers was conducted by mixing fly ash, sodium silicate solution, NaOH and water. The samples were cured at 60?C for 48h after staying at room temperature in covering mold for 24 h. X - ray diffraction, Fourier transform infra - red and Scanning electron microscope measurements were conducted on the samples after 28 days of geopolymerization process. X-ray diffraction measurements of lignite fly ash samples show anhydrite as the main constituent, while wood fly ash samples consist of calcite, albite and gypsum minerals. Beside of determination of physical-chemical properties, the aim of this study was radiological characterization of lignite fly ash, wood fly ash and the obtained geopolymer products. Activity concentration of 40K and radionuclides from the 238U and 232Th decay series in ash samples and fly ash-based geopolymers were determined by means of gamma-ray spectrometry, and the absorbed dose rate rate (D) and the annual effective dose rate (E) were calculated in accordance with the UNSCEAR 2000 report.

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Monitoring of Fluctuations in the Physical and Chemical Properties of a High-Calcium Fly Ash

MRS Proceedings ◽

10.1557/proc-113-107 ◽

1987 ◽

Vol 113 ◽

Cited By ~ 8

Author(s):

Scott Schlorholtz ◽

Ken Bergeson ◽

Turgut Demirel

Keyword(s):

Fly Ash ◽

Chemical Properties ◽

Operating Conditions ◽

Physical And Chemical Properties ◽

X Ray Diffraction ◽

X Ray ◽

Morphological Studies ◽

High Calcium ◽

Physical And Chemical ◽

And Chemical Properties

ABSTRACTThe physical and chemical properties of fly ash produced at Ottumwa Generating Station have been monitored since April, 1985. The fly ash is produced from burning a low sulfur, sub-bituminous coal obtained from the Powder River Basin near Gillette, Wyoming. One-hundred and sixty samples of fly ash were obtained during the two year period. All of the samples were subjected to physical testing as specified by ASTM C 311. About one-hundred of the samples were also subjected to a series of tests designed to monitor the self-cementing properties of the fly ash. Many of the fly ash samples were subjected to x-ray diffraction and fluorescence analysis to define the mineralogical and chemical composition of the bulk fly ash as a function of sampling date. Hydration products in selected hardened fly ash pastes, were studied by x-ray diffraction and scanning electron microscopy. The studies indicated that power plant operating conditions influenced the compressive strength of the fly ash paste specimens. Mineralogical and morphological studies of the fly ash pastes indicated that stratlingite formation occurred in the highstrength specimens, while ettringite was the major hydration product evident in the low-strength specimens.

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Structural and Chemical Properties of Geopolymer Gels Incorporated with Neodymium and Samarium

Gels ◽

10.3390/gels7040195 ◽

2021 ◽

Vol 7 (4) ◽

pp. 195

Author(s):

Snežana S. S. Nenadović ◽

Ljiljana M. Kljajević ◽

Marija M. Ivanović ◽

Miljana M. Mirković ◽

Nadežda Radmilović ◽

...

Keyword(s):

Rare Earth ◽

Photoelectron Spectroscopy ◽

Chemical Properties ◽

Alkali Activation ◽

Tetrahedral Coordination ◽

X Ray Diffraction ◽

Tem Analysis ◽

X Ray ◽

Transmission Electron ◽

Na Ions

The present work was focused on doping of 1% and 5% both of Nd2O3 and Sm2O3 in geopolymer gels. One of the main goals was to determine the influence of the behavior of Nd and Sm as dopants and structural nanoparticles changes of the final geopolymer formed. It is shown that the disorder formed by alkali activation of metakaolin can accommodate the rare earth cations Nd3+ and Sm3+ into their aluminosilicate framework structure. The main geopolymerization product identified in gels is Al-rich (Na)-AS-H gel comprising Al and Si in tetrahedral coordination. Na+ ions were balancing the negative charge resulting from Al3+ in tetrahedral coordination. The changes in the structures of the final product (geopolymer/Nd2O3; Sm2O3), has been characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) analysis with energy dispersive spectrometry (EDS). Nucleation at the seed surfaces leads to the formation of phase-separated gels from rare earth phase early in the reaction process. It is confirmed that Nd and Sm have been shown to form unstable hydroxides Nd(OH)3 and Sm(OH)3 that are in equilibrium with the corresponding oxides.

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Properties of Geopolymer Paste from Fly Ash Blended with Metakaolin as Pervious Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.690.179 ◽

2016 ◽

Vol 690 ◽

pp. 179-186 ◽

Cited By ~ 1

Author(s):

Phachongkit Boonanunwong ◽

Pimpawee Keawpapasson ◽

Chayanee Tippayasam ◽

Parjaree Thavorniti ◽

Prinya Chindaprasirt ◽

...

Keyword(s):

Compressive Strength ◽

Fourier Transform ◽

Fly Ash ◽

Coarse Aggregate ◽

Chemical Compositions ◽

Geopolymer Concrete ◽

X Ray Diffraction ◽

X Ray ◽

Lignite Fly Ash ◽

Scanning Electron

The purpose of this research was to study pervious geopolymer concrete with different amounts of lignite fly ash (F), metakaolin (M), sodium silicate (NS) and 8 mol/L sodium hydroxide (NH) solution. Constant NS/NH ratio of 0.5, three alkali liquid/pozzolan (L/P) ratios viz., 0.5, 0.6 and 0.7 and pozzolan to coarse aggregate ratio of 1:8 were used. The compressive strengths of 50×50×50 mm3 cube specimens were tested at the age of 28 days. In addition, compressive strengths of 100 mm in diameter and 200 mm in height cylindrical specimens were tested at the age of 7, 14, 21 and 28 days. The chemical compositions and microstructures of specimens were characterized by X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM), respectively.The mixture with 50%F+50%M and L/P ratio of 0.7 was the best proportion for pervious geopolymer concrete according to the compressive strength, good permeability and microstructural images. The bond of Si-O-Al and Si-O-Si characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectra confirmed the developed geopolymeric structure.

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Numerical Simulation of Combustion and Characteristics of Fly Ash and Slag in a “V-type” Waste Incinerator

Energies ◽

10.3390/en14227518 ◽

2021 ◽

Vol 14 (22) ◽

pp. 7518

Author(s):

Zixue Luo ◽

Wei Chen ◽

Yue Wang ◽

Qiang Cheng ◽

Xiaohua Yuan ◽

...

Keyword(s):

Fly Ash ◽

Cfd Simulation ◽

Combustion Process ◽

Measured Data ◽

Waste Incinerator ◽

X Ray Diffraction ◽

Simulation Data ◽

X Ray ◽

Changing Trend ◽

Computational Fluid Dynamics Cfd

This study is focused on a “V-type” waste incinerator for municipal solid waste (MSW) combustion. Computational fluid dynamics (CFD) methods are used to study the MSW combustion process. The characteristics of fly ash and slag are analyzed by using a laser particle analyzer, scanning electron microscope, X-ray fluorescence, and X-ray diffraction. The results show that the error between the CFD simulation data and measured data is less than 10%, and the changing trend of the combustion process is well-modeled. The fly ash mainly has an irregular spherical or ellipsoid structure, whereas the slag mainly has an irregular porous structure. The main constituents of the ash and slag are CaO and SiO2, along with heavy metal elements such as Cu, Pb, and Cr.

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Thermoluminescent and X-ray diffraction methods in dating of ceramics from archaeological excavations of the Orikti monument (Almaty region)

Chemical Bulletin of Kazakh National University ◽

10.15328/cb1143 ◽

2020 ◽

pp. 4-10

Author(s):

Askar Bakhadur ◽

Nadezhda Aluker ◽

Galymzhan Bekseitov ◽

Yerbolat Ospanov ◽

Bolat Uralbekov

Keyword(s):

Dose Rate ◽

Dose Range ◽

Sampling Site ◽

Absorbed Dose ◽

Average Dose ◽

Preparation Technique ◽

X Ray Diffraction ◽

Absorbed Dose Rate ◽

X Ray ◽

Ceramic Samples

In this work, the ages of archaeological ceramics were determined by the thermoluminescent method after X-ray diffraction analysis (XRD) of ceramic samples, which confirms that quartz is the main component phase of the products. This allowed to use the sample preparation technique without isolating the quartz phase from the ceramic sample. Silicon oxide based soil-equivalent thermoluminescent detectors were used to determine the annual absorbed dose rate at the sampling site. The average dose rate at sampling site was 0.62 ± 0.02 cGy/year. Calculation of the ceramics ages was carried out after checking the linearity of lightsums accumulation for samples in the dose range up to 2000 cGy. Based on the performed studies, the ages of the ceramic products were determined that do not contradict to archaeologists dating of these products. It is proposed to use the procedure for determining ceramic samples by the thermoluminescent method after their phase composition identification by XRD. In the case of the predominant mineral composition of quartz phase (the proportion of quartz is more than 60% of the total composition of ceramics), the measurements can be carried out without the quartz isolating; while presence of clay mineral fractions commensurate with quartz levels can lead to the separation of the quartz.

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Born out of Fire and Ice: Polymorph Studies of the Antiviral Famciclovir

Crystals ◽

10.3390/cryst11020129 ◽

2021 ◽

Vol 11 (2) ◽

pp. 129

Author(s):

Liana Vella-Zarb ◽

Ulrich Baisch

Keyword(s):

Variable Temperature ◽

Chemical Properties ◽

Crystal Form ◽

X Ray Diffraction ◽

Crystal Forms ◽

X Ray ◽

Physical Chemical ◽

Diffraction Patterns ◽

Crystalline Forms

There is much interest and focus on solid forms of famciclovir. However, in spite of the abundance of reported differences in oral bioavailability, compressibility, and other physical–chemical properties of the various crystal forms of this drug, very little precise structural analysis is available in the literature to date. The form used in the commercial formulation is the anhydrous form I. Patents and patent applications report three different anhydrous crystalline forms on the basis of unindexed powder diffraction patterns. Single-crystal and variable-temperature X-ray diffraction experiments using the commercially available anhydrous form of famciclovir were carried out and led not only to the crystal structure determination of the anhydrous form I, but also to discovery of a new crystal form of anhydrous famciclovir from powder data.

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Physical and Mechanical Properties of Cement Paste Were Used Partially with Fly Ash and Kaolin Waste

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.866.199 ◽

2017 ◽

Vol 866 ◽

pp. 199-203

Author(s):

Chidchanok Chainej ◽

Suparut Narksitipan ◽

Nittaya Jaitanong

Keyword(s):

Mechanical Properties ◽

Fly Ash ◽

Room Temperature ◽

Physical And Mechanical Properties ◽

Partial Replacement ◽

X Ray Diffraction ◽

X Ray ◽

Lime Water ◽

Diffraction Patterns ◽

Iron Mold

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.

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Physico-Chemical and Morphological Changes of Sayong Kaolinite Clay Treated with Sulphuric Acid for Enzyme Immobilization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.832.589 ◽

2013 ◽

Vol 832 ◽

pp. 589-595 ◽

Cited By ~ 1

Author(s):

N.A. Edama ◽

A. Sulaiman ◽

K.H. Ku Hamid ◽

M.N. Muhd Rodhi ◽

Mohibah Musa ◽

...

Keyword(s):

Surface Area ◽

Sulphuric Acid ◽

Enzyme Immobilization ◽

Morphological Changes ◽

Chemical Properties ◽

X Ray Diffraction ◽

Kaolinite Clay ◽

X Ray ◽

Mineral Oxides ◽

Physico Chemical

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.

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Investigations of Actinide Metals and Compounds under Pressure Provide Important Insights into Bonding and Chemistry

MRS Proceedings ◽

10.1557/proc-802-dd1.5 ◽

2003 ◽

Vol 802 ◽

Cited By ~ 3

Author(s):

R. G. Haire ◽

S. Heathman ◽

T. Le Bihan ◽

A. Lindbaum ◽

M. Iridi

Keyword(s):

Structural Changes ◽

Chemical Properties ◽

X Ray Diffraction ◽

Interatomic Distances ◽

X Ray ◽

Effect Of Pressure ◽

Electronic Configurations ◽

5F Electrons ◽

Actinide Series ◽

Alloys And Compounds

ABSTRACTOne effect of pressure on elements and compounds is to decease their interatomic distances, which can bring about dramatic perturbations in their electronic nature and bonding, which can be reflected in changes in physical and/or chemical properties. One important issue in the actinide series of elements is the effect of pressure on the 5f-electrons. We have probed changes in electronic behavior with pressure by monitoring structure by X-ray diffraction, and have studied several actinide metals and compounds from thorium through einsteinium. These studies have employed angle dispersive diffraction using synchrotron radiation, and energy dispersive techniques via conventional X-ray sources. The 5f-electrons of actinide metals and their alloys are often affected significantly by pressure, while with compounds, the structural changes are often not linked to the involvement of 5 f-electron. We shall present some of our more recent findings from studies of selected actinide metals, alloys and compounds under pressure. A discussion of the results in terms of the changes in electronic configurations and bonding with regard to the element's position in the series is also addressed.

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Characterization of Fly Ash Generated from Matla Power Station in Mpumalanga, South Africa

E-Journal of Chemistry ◽

10.1155/2012/451801 ◽

2012 ◽

Vol 9 (4) ◽

pp. 1788-1795 ◽

Cited By ~ 13

Author(s):

Olushola S. Ayanda ◽

Olalekan S. Fatoki ◽

Folahan A. Adekola ◽

Bhekumusa J. Ximba

Keyword(s):

Fly Ash ◽

Inductively Coupled Plasma ◽

Coal Fly Ash ◽

Harmful Effect ◽

Point Of Zero Charge ◽

X Ray Diffraction ◽

Power Station ◽

X Ray ◽

Inductively Coupled ◽

Plasma Mass Spectrometry

In this study, fly ash was obtained from Matla power station and the physicochemical properties investigated. The fly ash was characterized by x-ray fluorescence, x-ray diffraction, scanning electron microscopy, and inductively coupled plasma mass spectrometry. Surface area, particle size, ash and carbon contents, pH, and point of zero charge were also measured. The results showed that the fly ash is alkaline and consists mainly of mullite (Al6Si2O13) and quartz (SiO2). Highly toxic metals As, Sb, Cd, Cr, and Pb as well as metals that are essential to health in trace amounts were also present. The storage and disposal of coal fly ash can thus lead to the release of leached metals into soils, surface and ground waters, find way into the ecological systems and then cause harmful effect to man and its environments.

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