Effect of Illite Clay and Divalent Cations on Bitumen Recovery

The adverse effect of illite clay on bitumen recovery was found to be related to its acidity. The addition of calcium or magnesium ions to the flotation deionized water had a marginal effect on bitumen recovery when measured using a Denver flotation cell. However, the co‐addition of illite clay and divalent cations caused a significant reduction in bitumen recovery. The effect was found to be compounded at a lower process temperature and low pH values. Zeta potential distributions of illite suspensions and bitumen emulsions were measured individually and as a mixture to investigate the effect of divalent cations on the interaction between bitumen and illite clay. The presence of 1 mM calcium or magnesium ions in deionized water had a significant effect on the interactions between bitumen and illite clay. Slime coating of illite onto bitumen was not observed in zeta potential distribution measurements performed in alkaline tailings water.