A new way of identification of minerals was suggested. The identification was based on chemometric analysis of measured IR spectra of selected minerals. IR spectra were collected using diffuse reflectance technique. The discriminant analysis and principal component analysis were used as chemometric methods. Five statistical models were created for separation and identification of clay minerals. Up to 60 samples of various mineral standards (clay minerals, feldspars, carbonates, sulphates and quartz) from different localities were selected for the creation of statistical models. The results of this study confirm that the discriminant analysis of IR spectra of minerals could provide a powerful tool for mineral identification. Even differentiation of muscovite from illite and identification of mixed structures of illite-smectite were achieved., Michal Ritz, Lenka Vaculíková and Eva Plevová., and Obsahuje bibliografii
The objective of this work is the chemometric quantification of minerals in rocks. A chemometric method was developed for the determination of chlorite, muscovite, albite and quartz in claystones and clay shales using infrared spectroscopy. Bromide pellets and diffuse reflectance were used to measure the infrared spectra; principa l component analysis and partial least-squares regression were used as chemometric methods. Spectral regions (4000-3000 cm-1 and 1300-400 cm-1) containing important spectral information were chosen by principal compone nt analysis. The calibration models were created by a partial least-squares regression. The mean relative error and relative standard deviation were calculated for the assessment of accuracy and reproducibility. The value of the mean relative error was about 10 % for most of the calibration models. The value of the relative standard deviation ranged from 1.1 to 3.0 % for most calibration models based on diffuse reflectance spectra and from 4.0 to 9.2 % for most calibration models based on spectra obtained with bromide pellets., Michal Ritz, Lenka Vaculíková, Eva Plevová, Dalibor Matýsek and Jiří Mališ., and Obsahuje bibliografické odkazy
Chemical Quantitative Phase Analysis (CQPA) suggested originally for magmatic rocks (Klika et al., 1986) now is tested for the quantitative mineral determination of coal. This method is based on the optimization procedure. For the evaluation of mineral contents, 5 coal samples were selected and the following analytical data were determined: a) chemical analyses (XRF, titrimetric and gravimetric analytical methods), b) qualitative mineral composition (the X-ray powder diffraction, SEM-EDX and image analyses), c) crystallochemical formulae of minerals. The calculated percentages of minerals obtained by CQPA were compared with calculated percentages of minerals obtained by Raask´s method. Simple statistical evaluation showed that calculation of minerals by CQPA program delivers considerable improvement of results., Michal Ritz and Zdeněk Klika., and Obsahuje bibliografii
Hg(II) ions dissolved in aqueous solutions were adsorbed by montmorillonite (MMT). The Hg(II) ion-exchange was strongly limited by the competition with H+ ions: the maximal amounts of adsorbed Hg(II) and H+ ions were 0.21 mmol g-1 and 1.10 mmol g-1, respectively. MMTs saturated with Hg(II) (Hg-MMTs) were examined by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermal analysis. Hg(II) ions, such as Hg2+ and [Hg(OH)+], along with H+ ones were mostly adsorbed on permanent sites (75 % of cation exchange capacity (CEC)) and also on pH dependent surface sites (25 % of CEC). While heating, Hg-MMTs was loosing their mass up to 700 °C as a result of the MMT dehydration and dehydroxylation accompanied by release of adsorbed Hg(II)., Petr Praus, Marcela Motáková and Michal Ritz., and Obsahuje bibliografii