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. 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.

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.

X-Ray Powder Diffraction For Studying the Mineralogy of fly ash

1987 ◽  
Vol 113 ◽  
Author(s):  
Gregory I. McCarthy
Keyword(s):  
Fly Ash ◽  
Powder Diffraction ◽  
Reference Materials ◽  
Standard Reference Materials ◽  
National Bureau ◽  
Fly Ashes ◽  
X Ray ◽  
High Calcium

ABSTRACTA brief summary of the use of x-ray powder diffraction for studying the mineralogy of fly ash is presented. Mineralogies of low-, intermediate- and high-calcium fly ashes are discussed and illustrated by results from XRD characterization of U.S. National Bureau of Standards fly ash Standard Reference Materials.

Standard Reference Materials For X-Ray Diffraction Part II. Calibration Using d-Spacing Standards

1987 ◽  
Vol 2 (4) ◽  
pp. 242-248 ◽  
Author(s):  
W. Wong-Ng ◽  
C. R. Hubbard
Keyword(s):  
Sample Preparation ◽  
Reference Materials ◽  
Theoretical Basis ◽  
Internal Standard ◽  
High Accuracy ◽  
Standard Reference Materials ◽  
National Bureau ◽  
X Ray Diffraction ◽  
X Ray ◽  
External Standard

AbstractExternal standard and internal standard calibrations are important procedures for achieving high accuracy in X-ray powder diffraction studies. The theoretical basis as well as procedures for obtaining calibration curves are given. Methods and examples of selecting Standard Reference Materials (SRMs) which are produced and issued by the National Bureau of Standards (NBS), and procedures of sample preparation with these standards are also described. Three examples are presented to indicate the value of using SRMs.

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.

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

Preparation and Certification of Standard Reference Materials to be Used in the Determination of Retained Austenite in Steels

1982 ◽  
Vol 26 ◽  
pp. 137-140
Author(s):  
George E. Hicho ◽  
Earl E. Eaton
Keyword(s):  
Reference Materials ◽  
Retained Austenite ◽  
Solid Phase ◽  
Standard Reference Materials ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Face Centered ◽  
Materials Used ◽  
Steel Hardening

In the steel hardening process, steel is heated to a temperature where a face-centered-cubic solid phase called austenite is formed. After a stabilization period, the steel is quenched into a medium which transforms the austenite into a metastable, body-centered-tetragonal solid phase called martensite. On occasion the austenite is not entirely transformed into martensite and some austenite remains. This untransformed (retained) austenite is sometimes detrimental to the finished product, and often there are requirements as to the amount of retained austenite permitted In the finished product.X-ray diffraction procedures (XRD) are normally used to determine the amount of retained austenite and this paper describes the preparation and characterization of the Standard Reference Materials used to calibrate x-ray diffraction units.

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