Factors affecting bitumen recovery from oil sands.

Abstract

The oil sands deposits of northern Alberta are providing more than 15 percent of Canada's petroleum requirement. To meet this demand, the modified Clark Hot Water Extraction Process (HWEP) is used to recover bitumen from surface mineable oil sands. Several ore components that can potentially effect processability have been previously identified, namely ultra-fine clays and organic rich solids (ORS). In this thesis the use of ultra fines (<0.3 mum) and ORS to predict ore process problems has been explored. It was found that the ORS content of an ore is more appropriate for predicting absolute bitumen recoveries than the more commonly used fines and clay values. Critical ultra-fines and cation concentrations are shown to trigger the sludging process. However, these two components are difficult to measure and their use as a characterisation tool would probably be too expensive for general application. In view of this problem, a simple, inexpensive evaluation procedure was developed to identify anomalous ores. This involves using a jar test to provide a qualitative assessment of the segregating-non segregating boundary conditions for bitumen separation. More extensive characterisation and testing can then be performed on problem samples. (Abstract shortened by UMI.)