Quantification of the mineralogical composition of clays using FTIR spectroscopy

Development of far-infrared attenuated total reflectance spectroscopy for the mineralogical analysis of shales

“…Subsequently, this may have caused the PLS model to assign some of the smectite to illite. Similar issues have been described in other studies and illustrate the need to expand the number of mineral standards used in the chemometric models [10,16]. In the case of quartz, the predicted content and the XRD agree very well at low weight percentages, but some deviations were observed at higher levels.…”

“…The MIR spectrum comprises a number of fundamental modes of vibration (i.e., stretching and bending movements) that involve either a change in the bond length or bond angle [7]. Despite MIR spectroscopy being able to provide useful information regarding the chemical composition, a number of challenges still exist, particularly with respect to mineral and clay quantification [16]. Some IR absorption bands (i.e., SiAO stretch) that typically occur in many different mineral groups (i.e., silicates, clays) are broad and overlap with each other and this makes quantitative analysis extremely challenging.…”

Infrared Attenuated Total Reflectance Spectroscopy: An Innovative Strategy for Analyzing Mineral Components in Energy Relevant Systems

“…While the illite content throughout all shale samples is over predicted, the results for smectite with the exception of group A and D are under predicted, although the prediction error of illite and montmorillonite content in the validation set was at 2.5 and 3.6 wt%, respectively. Similar issues were experienced by Kaufhold et al (2012)13. Based on 57 reference materials, manual pattern addition of the respective IR spectra was used to quantify the mineralogical composition of real world bentonites and clays.…”

Soil Chemical Insights Provided through Vibrational Spectroscopy

“…Others have calibrated their approach using mineral assemblages and validated the approach using clays or rocks of known mineral composition as determined by XRD (Breen et al, 2008;Kaufhold et al, 2012). There have also been some who have applied models to quantify mineral content in soils (Bruckman and Wriessnig, 2013).…”