Analysis of Athabasca oil sand by near-infrared–diffuse reflectance spectroscopy
A near-infrared–diffuse reflectance spectroscopy (NIR–DR) method is described for the measurement of the bitumen and solids content in Athabasca oil sand over a 15 m vertical transect of a 7 cm diameter core at a sampling resolution of 1 cm. Principal component regression and partial least squares statistical techniques were evaluated as tools for optimizing the calibration models. The two techniques were found to be comparable and satisfactory for this application. Surface roughness was found to exhibit a significant effect on bitumen results. Sampling frequency studies showed that to attain a target precision of 5% for bitumen and solids, and to reduce errors arising from heterogeneity, measurements should be made on areas larger than 1 cm2.