Application of reflectance parameters in the estimation of the structural order of coals and carbonaceous materials. Precision and bias of measurements derived from the ICCP structural working group

Abstract

Optical reflectance of vitrinite is one of the fundamental physical properties that have been used for the study of coal and carbonaceous materials. Organic matter in coals and carbonaceous matter consists mainly of aromatic lamellae, whose dimensions and spatial orientation define its internal structure. Various reflectance parameters describe well the average degree of order of the molecular structure of organic matter. Moreover, reflectance A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPTGood correlations were found between the reflectance parameters studied and structural factors obtained by comparative methods. The reflectance parameters examined proved to be very sensitive to any changes of the structural order of coals and carbonaceous materials and seem to be a perfect complement to structural studies made by X-ray diffraction or Raman spectroscopy.

Simple procedure for an estimation of the coal rank using micro-Raman spectroscopy

“…The assumption of only two main bands (G and D) in the first-order spectrum of coals and chars has been made by several authors (Bustin et al, 1995;Green et al, 1983;Kelemen and Fang, 2001;Liu et al, 2014;Pusz et al, 2014;Quirico et al, 2005). Others use a third band between D-and G-bands (Johnson et al, 1986;Li et al, 1996), either on the high frequency side of the G-band (Rodrigues et al, 2013;Wopenka and Pasteris, 1993), or on the low frequency side of the D-band (Nestler et al, 2003;Zerda et al, 1981) in the fitting procedure.…”

“…Rank is an important parameter to decide the application of the coal in industry (Hook, 1977). It correlates strongly to volatile matter content and calorific value of the coal as well as to other chemical parameters that reflect the changes taking place in the coal molecular structure during maturation (Pusz et al, 2014;Thomas, 2013).…”

“…We would like to emphasize that we present only positions and widths of the Raman lines because they practically do not depend on the scattering geometry. Even though the area ratio of the D-band/G-band is the most common parameter illustrating the structural order of coal an carbonaceous material (Ferrari, 2007;Pusz et al, 2014;Tuinstra and Koenig, 1970), the intensities of the D-and Gbands (as well their ratio) will be strongly dependent on the scattering configuration and the crystalline grain orientation (Tan et al, 2004). Wopenka and Pasteris (1993) name the D-band width as a maturity indicator of coals, but neither area ratio nor intensity ratio of the D-and Gbands.…”

Burial and thermal history modelling of the Upper Carboniferous strata based on vitrinite refl ectance data from Bzie-Dębina-60 borehole (Upper Silesian Coal Basin, southern Poland)

“…The applied microscopical investigations closely followed the guidelines published by e.g. the usual International Committee for Coal and Organic Petrology (ICCP) procedures (ISO 7404-5, 2009), and further discussed by Pusz et al (2014) and Hackley et al (2015).…”

Thermal history of the lower Carboniferous Culm Basin in the Nízký Jeseník Mts. (NE Bohemian Massif, Czech Republic and Poland)

“…Mineral standards of known reflectance were used for calibration: sapphire (0.590%), yttrium-aluminium garnet (0.901%), gadolinium-gallium garnet (1.718%), cubic zirconium (3.130%) and strontium-titanate (5.39%). The applied microscopical investigations closely followed the guidelines published by Taylor et al (1998), Pusz et al (2014) and Hackley et al (2015). VR r was used as an input parameter for the estimation of maximum palaeotemperature after Barker and Pawlewicz (1994).…”