Quantitative XRD measurement of mineral matter in Gondwana coals using the Rietveld method

✍ Scribed by A. . Hutton; A.J. Mandile

• Book ID: 104354163
• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 856 KB
• Volume: 23
• Category: Article
• ISSN: 1464-343X
• DOI: 10.1016/s0899-5362(96)00052-8

✦ Synopsis

Organic matter behaves as amorphous material to X-rays and the presence of organic matter is manifested as an 'organic hump' on a standard X-ray diffraction trace. Empirical calibration curves can be used to determine the weight of organic matter from the trace. The subsequent weights of the organic matter can be input data for the Rietveld method and used to calculate the mineral contents, weighted to the organic content in the respective samples. The Rietveld quantitative method is a standardless, non-destructive technique that relies on crystal unit cell parameters of the minerals being analysed. Rietveld parameters, or variables causing intensity aberrations in the data, are adjusted theoretically, by refinement, to fit a synthetic (or calculated) profile to the measured pattern. In this paper, the mineralogy of a suite of African and Australian coal samples, calculated by the Rietveld method, ash analyses and other coal quality data are presented to test the validity of the methodology for Gondwana coals.