Rietveld quantitative X-ray diffraction analysis of NIST fly ash standard reference materials
Rietveld quantitative X-ray diffraction analysis of NIST fly ash standard reference materials
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DOI：
10.1017/s0885715600011015
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发表时间：
2000-09
影响因子：
0.5
通讯作者：
Ryan S. Winburn;Dean G. Grier;G. Mccarthy;R. B. Peterson
中科院分区：
文献类型：
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作者：
Ryan S. Winburn;Dean G. Grier;G. Mccarthy;R. B. Peterson
对美国国家标准与技术研究所发布的飞灰标准参考物质 (SRM) 进行了 Rietveld 定量 X 射线衍射分析。使用金红石 (TiO2) 内标来定量玻璃含量，玻璃含量的重量范围为 65% 至 78%。采用了 GSAS Rietveld 代码。通过进行六次重复分析获得精度，并使用飞灰结晶相和非晶相的混合物来估计精度。三种低钙（ASTM F 级）飞灰（SRM 1633b、2689 和 2690）包含四种结晶相：石英、莫来石、赤铁矿和磁铁矿。 SRM 1633b 还含有可检测水平的石膏，这对于此类粉煤灰来说并不常见。高钙（ASTM C 级）飞灰 SRM 2691 具有 11 种结晶相，对所采用的 GSAS 版本提出了挑战，GSAS 只能精炼 9 种结晶相。开发了一种分析不同组的九相并对结果进行平均的方法，并用十一相模拟粉煤灰进行了令人满意的测试。将结果与十年前报告的大多数 SRM 的参考强度比方法半定量分析进行了比较。
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. The GSAS Rietveld 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 of GSAS employed, 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.