Froth handling technologies. part 1: froth washing and the partition of solids and water

Abstract

Improved froth handling technologies in primary and secondary oil sands flotation are important, especially as new extraction technologies for future projects may require the operation to be carried out at lower temperatures. One approach to reducing the ratio of solids or minerals to bitumen in "dirty" froth is by intimately contacting or washing it with clean water. The solids may be either oil-wet, water-wet, or bi-wet; their partitioning in the flotation vessel is determined by their wettability. In addition, the water chemistry can be studied by 180 and 2H isotopes to determine whether the water found in oil emulsions during various processing stages originates from the oil sands feed, the conditioning step, or the flood water addition and subsequent froth handling. Froth washing results indicated that a small amount of solids (-8%) remained in the froth. The solids wettability may be probed by direct microscopy or calorimetry. Finally, the preliminary isotope study shows promising results in determining the origin of the water in oil sands processing emulsions.