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

Energies ◽  
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.

MSWI fly ash particle size chemical and mineralogical characterization, before and after leaching tests, aimed to reuse. 

2021 ◽  
Author(s):  
Enrico Destefanis ◽  
Caterina Caviglia ◽  
Angelo Agostino ◽  
Davide Bernasconi ◽  
Linda Pastero ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Fly Ash ◽  
Waste Incinerator ◽  
X Ray Diffraction ◽  
Mswi Fly Ash ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Ms Analysis ◽  
Icp Ms

<p>Municipal solid waste incinerator (MSWI) fly ash can represent a sustainable source of construction materials, but it needs to be treated in order to remove dangerous substances as chlorides, sulfates, and heavy metals. The concentration of salts and heavy metals in fly ash usually exceeds the law threshold and so they are considered a hazardous waste, unsuitable for reuse in concrete and civil engineering applications.In this work, a complete characterization of fly ash coming from a northern Italy thermovalorization plant was investigated, both on the solid and leachates composition, focused on the particle size, by X-Ray fluorescence and X-Ray diffraction on the solid matrices and ICP-MS analysis on the leachates.Using mechanical sieving on several subsamples of fly ash, six different particle size were separated and analyzed, and compared to the bulk fly ash composition.The most abundant elements are represented by Ca, Cl, S, and Si; trace elements and heavy metals are mainly represented by Zn, Fe, Al, Pb. The XRF and ICP-MS analysis show a general increasing trend, as the particle size decrease, of Na, K, Cl, S, as well as Cr, Cd, Cu, Pb, Sb, Zn, Ba, both on solid and leachates composition; on the contrary Ca and Si decrease.After leaching Cl and K decrease consistently, while it can be observed an increase of all the other elements, due to the weight loss attributable mainly to the leaching of Na-K chlorides, that is confirmed also by the X-Ray diffraction analysis.</p>

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

2021 ◽  
pp. 6-6
Author(s):  
Milos Nenadovic ◽  
Claudio Ferone ◽  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Bratislav Todorovic ◽  
...  
Keyword(s):  
Fly Ash ◽  
Dose Rate ◽  
Combustion Process ◽  
Chemical Properties ◽  
Gamma Ray Spectrometry ◽  
Alkali Activation ◽  
X Ray Diffraction ◽  
Absorbed Dose Rate ◽  
X Ray ◽  
Lignite Fly Ash

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.

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

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.

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

1987 ◽  
Vol 113 ◽  
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.

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

2012 ◽  
Vol 9 (4) ◽  
pp. 1788-1795 ◽  
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.

Influence of Fly Ash on Corrosion Resistance of Refractory Forsterite-Spinel Ceramics

2021 ◽  
Vol 325 ◽  
pp. 181-187
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Corrosion Resistance ◽  
Fly Ash ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transition Zones ◽  
Refractory Ceramics ◽  
Scanning Electron

This article examines the influence of fly ash on corrosion resistance of refractory forsterite-spinel ceramics by molten iron as a corrosive medium. Fly ash in comparison with alumina were used as raw materials and sources of aluminium oxide for synthesis of forsterite-spinel refractory ceramics. Raw materials were milled, mixed in different ratios into two sets of mixtures and sintered at 1550°C for 2 hours. Samples were characterized by X-ray diffraction analysis and thermal dilatometric analysis. Crucibles were then made from the fired ceramic mixtures and fired together with iron at its melting point of 1535°C for 5 hours. The corrosion resistance was evaluated by scanning electron microscopy on the transition zones between iron and ceramics. Mixtures with increased amount of spinel had higher corrosion resistance and mixtures with fly ash were comparable to mixtures with alumina in terms of corrosion resistance and refractory properties.

Effect of Fly Ash and Slag on the Resistance to H2S Attack of Oil Well Cement

2009 ◽  
Vol 79-82 ◽  
pp. 71-74
Author(s):  
Qi Wang ◽  
Lin Qiao ◽  
Peng Song
Keyword(s):  
Fly Ash ◽  
Compression Strength ◽  
Blended Cement ◽  
Oil Well ◽  
X Ray Diffraction ◽  
X Ray ◽  
Curing Period ◽  
Oil Well Cement ◽  
Xrd Patterns ◽  
Well Cement

In this paper, the resistance to H2S attack of pastes made from slag-fly ash blended cement used in oil well (SFAOW) was studied, in which fly ash (FA) was used at replacement dosages of 30% to 60% by weight of slag. Samples of SCOW and SFAOW pastes were demoulded and cured by immersion in fresh water with 2 Mp H2S insulfflation under 130oC for 15 days. After this curing period, compression strength and permeability of the samples were investigated. The reaction mechanisms of H2S with the paste were carried out through a microstructure study, which included the use of x-ray diffraction (XRD) patterns and scanning electron microscope (SEM). Based on the obtained data in this study, incorporation of FA into SCOW results in the comparable effects in the resistance to H2S attack. When the replacement dosage of slag is about 40%, the paste exhibits the best performance on resistance to H2S attack with compression strength 36.58Mp.

scholarly journals Influence of Mineral Admixtures on Corrosion Inhibition Effect of Nitrites

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Mengna Yang ◽  
Junzhe Liu ◽  
Hui Wang ◽  
Yushun Li ◽  
Yanhua Dai ◽  
...  
Keyword(s):  
Fly Ash ◽  
Corrosion Inhibition ◽  
Ion Concentration ◽  
Mineral Admixtures ◽  
X Ray Diffraction ◽  
Nitrite Ion ◽  
X Ray ◽  
Inhibition Effect ◽  
Diffraction Patterns ◽  
Micro Analysis

Chemical quantitative analysis of effective anticorrosion component and micro-analysis of hydration products of fly ash and slag on the influence of the nitrites corrosion inhibition was studied by the free nitrite ion concentration and X-ray diffraction pattern. The free nitrite ion concentration was used to describe the corrosion inhibition effect of nitrites. And the X-ray diffraction patterns were used to analyze the adsorption properties. The research results show that fly ash and slag were beneficial for improving the corrosion inhibition effect of nitrites. Cement-based materials with slag at low content presented high free nitrite ion concentration, but the addition of low content of fly ash harmed the corrosion inhibition effect of nitrites. The specimens incorporated with both fly ash and slag can reach the highest free nitrite ion concentration when the compounding proportion was 1:1. It was concluded that the extent of mineral admixtures of the corrosion inhibition effect of nitrites was affected by its type and content.

Influence of Salt Aid on Combustion Synthesis of Nanocrystalline CeO2 Powders

2011 ◽  
Vol 412 ◽  
pp. 5-8 ◽  
Author(s):  
Ying Zhang ◽  
Ai Chen ◽  
Hai Rong Wang ◽  
Ze Song Li ◽  
Ying Ping Shen
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Combustion Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Particle Characteristics ◽  
Transmission Electron ◽  
Nanocrystalline Ceria ◽  
Scanning Electron

The present article reports the results of studies related to the synthesis of nanocrystalline ceria powder by combustion process using salt combustion aid. Cerium nitrate as oxidant and urea as fuel were used as reagents, Sodium Chloride was compared as combustion aid. The phase analysis and particle size were compared. The product was characterized by X-ray diffraction, Scanning electron microscopy and Transmission electron microscopy. The results showed that employment of starting fuel with combustion aid resulted in synthesizing nanocrystalline ceria powder with fine agglomerates. By using combustion aid, the energetics of the combustion reaction and particle characteristics have been changed.

scholarly journals STUDI TENTANG KONDUKTIVITAS DAN RESISTANSI TERMAL GEOPOLIMER BERPORI BERBASIS ABU TERBANG (FLY ASH)

2020 ◽  
Vol 16 (2) ◽  
pp. 161
Author(s):  
Sulfianty Sulfianty ◽  
Nurhayati Nurhayati ◽  
Subaer Subaer
Keyword(s):  
Fly Ash ◽  
X Ray Diffraction ◽  
X Ray

Telah dilakukan penelitian yang bertujuan untuk menyelidiki sifat konduktivitas dan resistansi termalnya. Pembuatan sampel dengan menambahkan agen pembentuk pori (H2O2) ke dalam pasta geopolimer yang diaktivasi menggunakan alkali, dikeringkan (curing) pada suhu 70 ̊C selama 24 jam dan disimpan pada ruang terbuka selama ± 3 hari. Pengujian awal meliputi pengujian porositas, massa jenis dan daya serap air sedangkan pengujian untuk  sampel geopolimer berpori sesuai standar SNI 03-0349-1989 terdiri dari X-ray Diffraction, mikroskop optik digital, konduktivitas dan resistansi termal serta resistansi api dan panas (Shock thermal). Berdasarkan hasil penelitian dapat disimpulkan bahwa penambahan H2O2 akan memperbesar porositas dan daya serap air sehingga massa jenis akan semakin kecil. Sampel yang sesuai standar SNI 03-0349-1989 berdasarkan pengujian awal adalah sampel dengan komposisi 1,6%. Hasil karakterisasi XRD menunjukan bahwa fase berbentuk amorf dengan intensitas tertinggi diperoleh oleh SiO2 dan hasil karakterisasi mikroskop optik digital menunjukan bahwa ukuran pori dari sampel tidak seragam berkisar antara 1-10 mm. Adapun hasil uji konduktivitas dan resistansi termal berturut-turut yaitu 0,77 W/m ̊K dan 0,02 K.m2/W. Serta uji resistansi api dan panas (shock thermal) menunjukan bahwa sampel dapat bertahan hingga 1300 ̊C. Hal ini menunjukan bahwa geopolimer berpori berbahan dasar abu terbang (Fly Ash) memiliki nilai konduktivitas dan resistansi termal yang rendah dan tahan terhadap suhu tinggi sehingga dapat diaplikasikan sebagai bahan isolasi termal yang baik dan ramah lingkungan.

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