Abstract: As-mined, naturally water-wet oil sand is mixed at the mine site with hot water and NaOH to produce a slurry containing entrained air. The slurry is pumped through a pipeline and is fed directly to a conventional gravity separation vessel. The pipeline is of sufficient length so that, in the course of being pumped therethrough, sufficient coalescence and aeration of bitumen occurs so that, when subsequently retained in the gravity separation vessel under quiescent conditions, a viable amount of the bitumen floats, forms froth, and is recovered.

Abstract: The mixer circuit comprises a vertically oriented, open-topped mixer vessel having a cylindrical side wall terminating with a shallow conical bottom. The bottom wall forms a central bottom outlet. Recycled slurry and fresh water streams are fed tangentially to the inner surface of the vessel, thereby forming a vortex. The oil sand enters as a continuous, free-flowing stream moving along a downward trajectory; the stream impinges the vortex, wherein it is dispersed and mixed to create slurry. The slurry exits through the bottom outlet, is screened to remove oversize material, and enters a holding vessel. Part of the slurry in the holding vessel is recycled to the mixer vessel through a pipe loop incorporating a pump. The slurry is energized by the pump and functions to maintain and partly create the rapidly moving vortex that carries out the mixing and lump-disintegration actions. The balance of the slurry in the holding vessel is pumped out as product.