Abstract: The primary tailings and middlings are combined and fed to a vessel having the general form of a deep cone thickener. The feed is deflected outwardly and generally horizontally by a baffle, as it is delivered to the vessel. Simultaneously, the outwardly radiating layer of newly added feed is contacted from below by an upwelling stream of aerated middlings, which stream moves in parallel with the aforesaid layer. Bitumen froth is formed and recovered. The upwelling stream is provided by circulating middlings through eductor/aerator assemblies and a plenum chamber mounted centrally in the body of middlings in the vessel. A generally circular circulation of middlings is generated. In this manner, the newly added bitumen is quickly and efficiently recovered. Recirculation of middlings to the aeration zone yields an additional recovery of bitumen. Use of the deep cone ensures that the tailings from the vessel are relatively low in water and bitumen content.

Abstract: An apparatus and process are described for homogenizing and subsampling process streams such as those present in the hot water extraction process for recovery of bitumen from tar sand. Such streams contain widely variable proportions of heavy oil, water, and solids. To obtain a representative analysis-size subsample from such a stream, a bulk sample is taken into a cylindrical open-topped vessel containing a coaxial cylindrical draft tube spaced from the internal wall of the vessel. A head element closes and seals the top of the vessel. An impellor extending into the draft tube through the head element is actuated to circulate the bulk sample along an elliptical flow path within the vessel. The vessel contents are maintained in a pressurized condition by the introduction of inert gas.

Abstract: An apparatus and process are described for homogenizing and subsampling process streams such as those present in the hot water extraction process for recovery of bitumen from tar sand. Such streams contain widely variable proportions of heavy oil, water, and solids. To obtain a representative analysis-size subsample from such a stream, a bulk sample is taken into a cylindrical open-topped vessel containing a coaxial cylindrical draft tube spaced from the internal wall of the vessel. A head element closes and seals the top of the vessel. An impellor extending into the draft tube through the head element is actuated to circulate the bulk sample along an elliptical flow path within the vessel. The vessel contents are maintained in a pressurized condition by the introduction of intert gas.

Abstract: This invention is an improvement on the hot water process for recovering bitumen from tar sand. The aqueous slurry of tar sand is introduced into a first vessel, termed the sand separation cell, containing a body of hot water. The coarse sand settles out and is discharged as tailings. The top product, comprising bitumen, water and fine sand, is transferred to a second vessel, termed the froth formation cell, containing a second body of hot water. In this latter cell, the bitumen forms froth and is recovered, and the fine solids and some water are recycled to the lower end of the sand separation cell. Because the coarse sand has previously been removed in the sand separation cell, good distribution of the feed across the cross-sectional area of the froth formation cell is achieved. This leads to good recoveries and froth quality.