Investigation of glassy phase silica in low calcium content fly ash by X‐ray photoelectron spectroscopy

Author(s):  
Siddharth Singh ◽  
Soumitra Maiti

2014 ◽  
Vol 34 (3) ◽  
pp. 841-849 ◽  
Author(s):  
M. Kanuchova ◽  
L. Kozakova ◽  
M. Drabova ◽  
M. Sisol ◽  
A. Estokova ◽  
...  


1991 ◽  
Vol 51 (1-2) ◽  
pp. 35-46 ◽  
Author(s):  
T. Ersez ◽  
J. Liesegang


1985 ◽  
Vol 34 (5) ◽  
pp. 303-305 ◽  
Author(s):  
Kichinosuke HIROKAWA


1986 ◽  
Vol 86 ◽  
Author(s):  
Myra M. Soroczak ◽  
H. C. Eaton ◽  
M. E. Tittlebaum

ABSTRACTThe reactivity of coal fly ash is dependent on the chemical composition of the surface. As reactions occur the ash particle size decreases and new material is available for reaction. This means that the near-surface chemistry can also be important. In the present study the surface chemistries of three ashes are determined by x-ray photoelectron spectroscopy both before and after exposure to a hydrating/leaching environment. Scanning electron microscopy is used to reveal ash morphology. The concentration of sulfur, found at the ash surfaces as a sulfate, and sodium decreased after leaching while the amount of iron and aluminum increased. Other elements, including calcium, increased and decreased with leaching depending on which ash was analyzed. Changes which occurred in the ash morphology after the removal of leachable elements are discussed.



2019 ◽  
Vol 284 ◽  
pp. 283-288 ◽  
Author(s):  
Anna Škvarlová ◽  
Mária Kaňuchová ◽  
Ľubica Kozáková ◽  
Eva Valušová ◽  
Marián Holub ◽  
...  




2018 ◽  
Vol 30 (7) ◽  
pp. 313-322 ◽  
Author(s):  
Gangapatnam V. P. Bhagath Singh ◽  
Challapalli Subrahmanyam ◽  
Kolluru V. L. Subramaniam


1978 ◽  
Vol 32 (3) ◽  
pp. 316-319 ◽  
Author(s):  
James A. Campbell ◽  
Richard D. Smith ◽  
L. E. Davis

X-ray photoelectron spectroscopy has been used to identify and determine the oxidation states of a number of major and minor elements present on the surface of fly ash particles. With the use of a sputtering-etching procedure, relative concentrations as a function of depth were obtained for Si, Al, Fe, Ca, Na, C, O, and S. The concentrations of Na, C, O, and S were found to decrease and Si, Al, and Fe were found to increase upon sputtering to a depth of approximately 50 Å.



1987 ◽  
Vol 113 ◽  
Author(s):  
Carol I. Kilgour ◽  
Sidney Diamond

ABSTRACTA low calcium fly ash, rich in iron oxide, was subjected to shaking in 1% HF for up to 20 hours, and measurements were made at intervals of the following parameters: total weight loss, composition of the dissolved material, x-ray peak intensities of crystalline components and residual glass, and internal structures present within the fly ash spheres as revealed by the progressive dissolution treatments. The same fly ash was subjected to similar but longer-term treatment with simulated cement pore solution (potassium and sodium hydroxide). The compositions of the magnetically separated fraction and the non-magnetic residue were also separately determined. As a result of these studies, it was suggested that: (a) the time at which all of the potassium is dissolved might be used as an indicator of the completion of glass dissolution; (b) the position of the x-ray band for residual (more resistant ) glass shifts to higher 2Θ angle before the glass is completely dissolved; (c) in this fly ash, as determined by chemical analysis, all of the iron is in the magnetically-separable fraction, a feature that permitted estimation of the overall glass composition; and (d) this fly ash contains certain poorly understood components including silica-rich spheres, small spheres yielding EDXA signals only for iron, and “patches” of silica and alumina bearing material not of mullite composition, but all of which are highly resistant to HF dissolution.



Sign in / Sign up

Export Citation Format

Share Document