X-ray Diffraction Analysis of Fly Ash. II. Results

1990 ◽  
Vol 34 ◽  
pp. 387-394 ◽  
Author(s):  
G. J. McCarthy ◽  
J. K. Solem
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Chemical Constituents ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Power Station ◽  
Crystalline Phases ◽  
X Ray ◽  
High Calcium

AbstractA protocol for semi-quantitative XRD analysis of fly ash has been applied to 178 ashes in studies of the typical mineralogy of high-calcium and iow-calcium fly ash, the consistency of fly ash mineralogy from a typical power station, the partitioning of chemical constituents into crystalline phases, and the crystalline phases relevant to the use of fly ash in concrete.

Rietveld quantitative X-ray diffraction analysis of NIST fly ash standard reference materials

2000 ◽  
Vol 15 (3) ◽  
pp. 163-172 ◽  
Author(s):  
Ryan S. Winburn ◽  
Dean G. Grier ◽  
Gregory J. McCarthy ◽  
Renee B. Peterson
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Reference Materials ◽  
Internal Standard ◽  
Standard Reference Materials ◽  
Ratio Method ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
High Calcium

Rietveld quantitative X-ray diffraction analysis of the fly ash Standard Reference Materials (SRMs) issued by the National Institute of Standards and Technologies was performed. A rutile (TiO2) internal standard was used to enable quantitation of the glass content, which ranged from 65% to 78% by weight. TheGSASRietveld code was employed. Precision was obtained by performing six replicates of an analysis, and accuracy was estimated using mixtures of fly ash crystalline phases and an amorphous phase. The three low-calcium (ASTM Class F) fly ashes (SRM 1633b, 2689 and 2690) contained four crystalline phases: quartz, mullite, hematite, and magnetite. SRM 1633b also contained a detectable level of gypsum, which is not common for this type of fly ash. The high-calcium (ASTM Class C) fly ash, SRM 2691, had eleven crystalline phases and presented a challenge for the version ofGSASemployed, which permits refinement of only nine crystalline phases. A method of analyzing different groups of nine phases and averaging the results was developed, and tested satisfactorily with an eleven-phase simulated fly ash. The results were compared to reference intensity ratio method semiquantitative analyses reported for most of these SRMs a decade ago.

X-Ray Diffraction Analysis of Fly ASH

1987 ◽  
Vol 31 ◽  
pp. 331-342 ◽  
Author(s):  
G.J. McCarthy ◽  
D.M. Johansen ◽  
S.J. Steinwand ◽  
A. Thedchanamoorthy
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Power Plants ◽  
Aluminosilicate Glass ◽  
Low Rank ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Calcium Aluminosilicate ◽  
Intensity Ratios

AbstractMethods for, and results from, x-ray diffraction analysis of large numbers of fly ash samples obtained from U.S. power plants are described. Qualitative XRD indicates that low-calcium/Class F fly ash (usually derived from bituminous coal) consists typically of the crystalline phases quartz, mullite, hematite and magnetite in a matrix of aluminosilicate glass. Highcalcium fly ash (derived from low-rank coal) has a much more complex assemblage of crystalline phases that typically includes these four phases plus lime, periclase, anhydrite, alkali sulfates, tricalcium aluminate, dicalcium silicate, melilite, merwinlte and a sodalite-structure phase. Glass compositions among the particles are more heterogeneous and range from calcium aluminate to sodium calcium aluminosilicate, Every ash studied Is mixed with an internal Intensity standard (rutile) so that Intensity ratios can be used to make comparisons of the relative amounts of crystalline phases. An error analysis was performed to define the level of uncertainty in making these comparisons. These intensity ratios will be used for quantitative XRD phase analyses when reference intensity ratios for each fly ash phase become available.

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.

Microstructure and X-Ray Diffraction Analysis of Aluminum-Fly Ash Composites Produced by Compocasting Method

2019 ◽  
Vol 49 (2) ◽  
pp. 20170609
Author(s):  
M. N. Ervina Efzan ◽  
N. Siti Syazwani ◽  
A. M. Mustafa Al Bakri ◽  
Wai Liew Kia
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
X Ray Diffraction ◽  
X Ray

Mechanical Properties of Fly Ash-Slag-Dredged Silt System Stimulated by Alkali

2013 ◽  
Vol 807-809 ◽  
pp. 1140-1146 ◽  
Author(s):  
Yi Xuan Chen ◽  
Xiu Li Sun ◽  
Zhi Hua Li
Keyword(s):  
Mechanical Properties ◽  
Shear Strength ◽  
Fly Ash ◽  
Construction Materials ◽  
Xrd Analysis ◽  
Test Results ◽  
X Ray Diffraction ◽  
Shear Tests ◽  
X Ray ◽  
Direct Shear Tests

The objective of this work is to investigate the stimulation effect of the addition of alkali on the fly ash and slag for stabilizing dredged silt. Based on the test results, a viable alternative for the final disposal of dredged silt as subgrade construction materials were proposed. For this purpose, several mixtures of dredged silt-fly ash-slag and alkali were prepared and stabilized/solidified. In this system, fly ash and slag were used as hardening agents (solidified materials) of dredged silt and alkali was used as activator of fly ash and slag. The shear strength of the mixture was tested by several direct shear tests. Furthermore, X-Ray Diffraction (XRD) analysis was used to determine the hydration products of the system. The specimens were tested in order to determine the shear strength changes versus hydration time and the alkali content. It is indicated that mechanical properties of solidified silt are improved significantly by addition of fly ash and slag stimulated by alkali.

Semi-Quantitative X-Ray Diffraction Analysis of Fly Ash by the Reference Intensity Ratio Method

1988 ◽  
Vol 136 ◽  
Author(s):  
Gregory J. McCarthy ◽  
A. Thedchanamoorthy
Keyword(s):  
Fly Ash ◽  
Diffraction Analysis ◽  
Intensity Ratio ◽  
Bituminous Coal ◽  
Low Rank ◽  
Standard Reference Materials ◽  
Ratio Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Common

ABSTRACTA protocol for relatively inexpensive and rapid semi-quantitative x-ray diffraction analysis of fly ash mineralogy by the Reference Intensity Ratio (RIR) method is described. RIR's for the common crystalline phases in fly ashes derived from low rank and bituminous coal are given. The method is semi-quantitative for some phases because of unavoidable overlaps of the stronger peaks suitable for quantitation. Use of the protocol is illustrated with the four fly ash Standard Reference Materials supplied by the National Institute of Standards and Technology. Recommendations for implementation of this protocol in other laboratories and for improvements in quantitation of fly ash mineralogy are given.

Analysis of the Ash from One Shanghai Plant Using XRD (X-Ray Diffraction)

2013 ◽  
Vol 664 ◽  
pp. 232-235
Author(s):  
Guo Xian Ma ◽  
Hai Ying Zhang
Keyword(s):  
Fly Ash ◽  
Pollution Control ◽  
Room Temperature ◽  
Thermal Characterization ◽  
Xrd Analysis ◽  
Air Pollution Control ◽  
X Ray Diffraction ◽  
X Ray ◽  
Calcium Silicates

This study aims to develop a methodology for thermal characterization of APC (air pollution control)fly ash using XRD (X-ray diffraction). It performed XRD analysis as a function of temperature between room temperature and 1200 °C. It is found that major mineralogical components of fly ash involve SiO2, CaCl2, Ca3Si2O7, Ca2SiO4–0.35H2O, Ca9Si6O21–H2O, K2Al2Si2O8–3.8H2O and AlCl3–4Al(OH)3–4H2O. Glass phases account for around 57%, which is conducive to reduction of energy in recycling of the ash. Salts decompose firstly with increase of temperature and then oxides derived from the decomposition process react with SiO2, forming silicates, calcium-silicates and aluminosilicates.

Analysis of the Cement-Stabilized Ash by XRD (X-Ray Diffraction)

2013 ◽  
Vol 811 ◽  
pp. 240-243
Author(s):  
Guo Xian Ma ◽  
Hai Ying Zhang
Keyword(s):  
Fly Ash ◽  
Pollution Control ◽  
Xrd Analysis ◽  
Air Pollution Control ◽  
Hydration Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
Time Period ◽  
Incineration Process ◽  
Mineralogical Compositions

APC (air pollution control) fly ash, generated in incineration process of municipal solid waste, is regarded as a hazardous waste because of enrichment of heavy metals. In this work, stabilization of the ash with cement was studied. In addition, XRD analysis of the cement stabilized body was performed as a function of conservation time period. It was It was found that the hydration products cement fly ash and other particles together, which rises with increase of the cement / ash ratio and duration of conservation. Major mineralogical compositions CaCO3, Ca (0H)2 and C-H-S hydration products. Content of Ca (0H)2 and C-H-S rises with increase of conservation period and cement / ash ratio.

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