Residual organic matter associated with toluene-extracted oil sands solids and its potential role in bitumen recovery via adsorption onto clay minerals

Adsorption of hydrocarbon components, particularly by clay minerals, has an important influence on the recovery of conventional oil from reservoir rocks. In the same vein, biwetted clay particles have been associated with bitumen losses during processing of surface-mined oil sands. In this work, we examined four oil sands with very different batch-extraction unit (BEU) bitumen recovery profiles. Bitumen-free solids from these ores were subjected to supercritical fluid extraction with methanol to separate quantitatively any toluene-insoluble, residual organic matter. The yield of extract correlated well with the amounts of solids in the fine (<44 \u3bcm) and clay (