Mineralogical and chemical composition of magnetic fly ash fraction

2013 ◽  
Vol 71 (4) ◽  
pp. 1673-1681 ◽  
Author(s):  
Xue Song Wang
Keyword(s):  
Fly Ash ◽  
Chemical Composition

Influence of Different Mineral Precursors on the Properties of Fly Ash Based Alkali-Activated Mortars

2018 ◽  
Vol 761 ◽  
pp. 73-78 ◽  
Author(s):  
Matej Špak ◽  
Pavel Raschman
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Chemical Composition ◽  
Coal Combustion ◽  
Pure Aluminum ◽  
Partial Replacement ◽  
Black Coal ◽  
Fly Ashes ◽  
Final Composition ◽  
Alkali Activated

Alkali-activated materials based on fly ash are widely developed and also produced on the present. Some of fly ashes are not suitable for production of alkali-activated materials because of their inconvenient chemical composition. Alumina-silicates are the most important components that are needed to accomplish the successful reaction. The proper content of amorphous phase of alumina-silicates and its proportion as well should be provided for the final composition of alkali-activated materials. The influence of pure aluminum oxide powder as well as raw milled natural perlite on mechanical properties and durability of alkali-activated mortars was investigated. These minerals were used as partial replacement of fly ash coming from black coal combustion. In addition, the mortars were prepared by using different alkali activators.

Modeling of Alteration Behavior on Blended Cementitious Materials

2011 ◽  
Author(s):  
Hitoshi Owada ◽  
Tomoko Ishii ◽  
Mayumi Takazawa ◽  
Hiroyasu Kato ◽  
Hiroyuki Sakamoto ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Fly Ash ◽  
Chemical Composition ◽  
Mineral Composition ◽  
Blast Furnace Slag ◽  
Fine Powder ◽  
Cementitious Materials ◽  
Leaching Tests ◽  
Measured Concentration ◽  
Furnace Slag

A “realistic alteration model” is needed for various cementitious materials. Hypothetical settings of mineral composition calculated based on the chemical composition of cement, such as Atkins’s model, have been used to estimate the alteration of cementitious material. However, model estimates for the concentration of certain elements such as Al and S in leachate have been different from experimental values. In a previous study, we created settings for a mineralogical alteration model by taking the initial chemical composition of cementitious materials from analysis results in experiments and applying their ratios to certain hydrated cement minerals, then added settings for secondary generated minerals in order to account for Ca leaching. This study of alteration estimates for ordinary portland cement (OPC) in groundwater showed that the change in Al and S concentrations in simulated leachate approached values for actual leachate[1]. In the present study, we develop an appropriate mineral alteration model for blended cementitious materials and conduct batch-type leaching experiments that use crushed samples of blast furnace slag cement (BFSC), silica cement (SC), and fly ash cement (FAC). The cement blends in these experiments used OPC blended with blast furnace slag of 70 wt.%, silica cement consisting of an amorphous silica fine powder of 20 wt.%, and fly ash of 30 wt.%. De-ionized water was used as the leaching solution. The solid-liquid ratios in the leaching tests were varied in order to simulate the alteration process of cement hydrates. The compositions of leachate and minerals obtained from leaching tests were compared with those obtained from models using hypothetical settings of mineral composition. We also consider an alteration model that corresponds to the diversity of these materials. As a result of applying the conventional OPC model to blended cementitious materials, the estimated Al concentration in the aqueous solution was significantly different from the measured concentration. We therefore propose an improved model that takes better account of Al behavior by using a more reliable initial mineral model for Al concentration in the solution.

Chemical composition, nutritional and toxicological evaluation of rice (Oryza sativa ) grown in fly ash amended soils

2012 ◽  
Vol 92 (13) ◽  
pp. 2721-2726 ◽  
Author(s):  
Kandlakunta Bhaskarachary ◽  
Punna Ramulu ◽  
Paruchuri Udayasekhararao ◽  
Sangras Bapurao ◽  
Krishnaswamy Kamala ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Fly Ash ◽  
Chemical Composition ◽  
Toxicological Evaluation ◽  
Amended Soils

scholarly journals The Impact of Coal Fly Ash Purification on Its Antibacterial Activity

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1002
Author(s):  
Seham Alterary ◽  
Narguess H. Marei
Keyword(s):  
Particle Size ◽  
Antibacterial Activity ◽  
Fly Ash ◽  
Chemical Composition ◽  
Bacterial Growth ◽  
Broth Culture ◽  
Growth Reduction ◽  
Laser Scattering ◽  
X Ray ◽  
The Impact

Fly ash (FA) is produced from coal power plants’ combustion. FA is used in the concrete industry, as an ingredient in the brick and paving. Knowledge of the chemical composition and toxic metal content in FA is essential for evaluating its environmental risks. This study aimed to assess FA purification effect on its antibacterial activity against Escherichia coli and Bacillus cereus, by calculating percent bacterial reduction. Moreover, centrifugation time effect on the purification process was evaluated. Chemical composition and properties of purified FA were determined and compared with raw FA, using Fourier transform Infrared (FTIR); X-ray diffraction (XRD); X-ray photoelectron spectroscopy (XPS); energy-dispersive X-ray (EDXA); carbon, hydrogen, nitrogen, and sulfur (CHNS) elemental analysis; moisture content; and loss-of-ignition. Particle size was predicted by using dynamic laser scattering, BET and scanning electron microscopy (SEM). The CHNS results showed that purified FA contains the highest carbon content (88.9%), as compared to raw FA (82.1%). The particle size distribution (PSD) of FA microspheres ranges from 48.53 ± 17.9 to 52.98 ± 19.4 µm by using SEM. PSD, using dynamic laser scattering, showed polydispersed and non-uniform size in raw FA, ranging in size from 107.1 to 1027 nm, while purified FA manifests a monodispersed size from 103.3 to 127.3 nm. FA showed the least bacterial growth reduction %, while the purified fly ash (FA2) showed the highest bacterial growth reduction %, as compared to the control bacterial broth culture without fly ash.

The Colorants Effects of Fe2O3 on Borosilicate Glasses Prepared from Subbituminous Fly Ash

2015 ◽  
Vol 1119 ◽  
pp. 731-735
Author(s):  
W. Rachniyom ◽  
Y. Ruangtaweep ◽  
K. Boonin ◽  
K. Phachana ◽  
J. Kaewkhao
Keyword(s):  
Refractive Index ◽  
Fly Ash ◽  
Chemical Composition ◽  
Crystal Structures ◽  
Absorption Spectra ◽  
Borosilicate Glasses ◽  
Ferrous Ions ◽  
Melt Quenching ◽  
Hardness Values

In this work, the subbituminous fly ash (SFA) in Thailand has been investigated for their compositions and crystal structures. Borosilicate glasses were prepare from SFA , B2O3, Na2O and various concentration of Fe2O3 by melt quenching technique. The results have shown that the chemical composition comprised with SiO2, Al2O3 and Fe2O3. The crystal structures of SFA were raised of mullite and quartz phases. The density and refractive index values of glasses were found to increase with increasing of Fe2O3 concentrations. The hardness values have been decreased with increasing of Fe2O3 content. The absorption spectra are corresponding to ferric and ferrous ions in wavelength of 440 nm and 1,050 nm and the color of glasses are green to yellow.

A Statistical Investigation on Particle to Particle Variation of Fly Ash Using SEM-AIA-EDAX Technique.

1989 ◽  
Vol 178 ◽  
Author(s):  
L. E. Barta ◽  
G. VÁmos ◽  
M. A. Toqan ◽  
J. D. Teare ◽  
J. M. BeÉr ◽  
...  
Keyword(s):  
Fly Ash ◽  
Chemical Composition ◽  
Random Variables ◽  
Statistical Investigation ◽  
Distribution Functions ◽  
Mineral Matter ◽  
Size Distributions ◽  
Bulk Analysis ◽  
Mean Values ◽  
Particle Properties

AbstractDue to the particle to particle variation of coal mineral properties and random coalescence of mineral particles during coal burnout, fly ash particle properties change from particle to particle. The variations of particle properties (e.g. SiO2 content, viscosity) can be mathematically described by random variables. Since bulk analysis of fly ash gives only the mean values of chosen random variables, it is considered insufficient to describe the fly ash behavior either in boiler slagging/fouling or in different concrete structures. SEM-AIA-EDAX technique was used to supply raw data for estimating the distribution functions of particle size and chemical compounds in Texas lignite minerals and fly ash and Eagle Butte fly ash. To determine the volume based size distributions of these samples from their area-based size distributions, Abelian transformation was used. To estimate the distribution functions of CaO and SiO2 contents of the samples, particle area fractions were used. The confidence limits were also calculated for the estimated parameters. By determining the distribution functions of particle viscosity and chemical composition, it was shown that in the case of Texas lignite the coal burnout does not cause significant changes in the mineral matter properties. It was observed that the properties of fly ash depended solely on the mineral matter properties. However, in the Eagle Butte case the coal burnout has a major effect on the fly ash size distribution and its chemical composition.

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