Characterization of Athabasca oil sands froth treatment tailings for heavy mineral recovery

Titanium (Ti) and zirconium (Zr) minerals (heavy minerals) in the Athabasca oil sands are concentrated in the bitumen froth treatment tailings during the hot water bitumen extraction operations. Recovery processes for these minerals have been explored since the 1970s, yet there is still no established process flowsheet to economically recover these minerals. We recently carried out a research project based on the knowledge of these previous studies. The objective of the project was to study the effect of residual bitumen removal methods from the froth treatment tailings on the separation characteristics of the heavy minerals contained in the tailings. The work reported in this paper is part of the project and it concerns the characterization of the froth treatment tailings. It was found that, rather than burning it off, the residual bitumen in the froth treatment tailings is worth recovering. Separation properties of the heavy minerals contained in the froth treatment tailings were studied by chemical assays, particle size-assay analysis, magnetic susceptibility measurements, gravity and magnetic separation, mineralogical analysis and scanning electron microscope (SEM) analysis coupled with energy dispersive x-ray (EDX) analysis.