The development of a reliable on-line method to monitor process streams is important for improved process control in oil sand extraction plants. The suitability of diffuse reflectance near-infrared (NIR) spectroscopy for this purpose has been tested in a pilot plant environment. Spectra of a feed slurry flowing through a pipe were measured with the use of an on-line fiber-optic probe. Data were collected throughout a nine-hour period during which ore type and slurry water content were varied. The feasibility of monitoring feed stream conditions is demonstrated by principal component analysis of the measured spectra. Clustering of these spectra according to ore type and water content enables the detection of deviations from and transitions between steady-state conditions of the process. Estimates are given of characteristic times for the process to reach a steady state after a change in condition has been initiated. The use of artificial neural networks for classifying spectra on the basis of ore type is also illustrated.
Waldemar I. Friesen, "Qualitative Analysis of Oil Sand Slurries Using On-Line NIR Spectroscopy," Appl. Spectrosc. 50, 1535-1540 (1996)