Abstract: A feedwell for a gravity separation vessel for introducing a feed stream such as oil sand slurry to the gravity separation vessel is provided comprising a walled member having an upper perimeter edge, a lower perimeter edge and a substantially continuous wall extending from the upper perimeter edge to the lower perimeter edge; an inlet for introducing the feed stream into the walled member positioned adjacent the substantially continuous wall; and a bottom floor having an opening and extending generally beneath the lower perimeter edge; whereby a perimeter of the opening is less than a perimeter of the walled member.

Abstract: A method and apparatus for recovering bitumen as froth from a feed stream having solids, water and bitumen is provided using a separating vessel having mounted thereon a downpipe assembly, the downpipe assembly having at least one downpipe and a nozzle in fluid communication with each downpipe, for aerating a stream of middlings withdrawn from the separating vessel and reintroducing the aerated middlings back to the separating vessel.

Abstract: A process for extracting bitumen from oil sand, comprising: mixing oil sand with process water to produce an oil sand slurry containing bitumen, sand, water and entrained air; conditioning the oil sand slurry; optionally flooding the conditioned oil sand slurry with flood water to dilute the slurry, if required; introducing the slurry into a primary separation vessel wherein separate layers of primary bitumen froth, middlings and sand tailings are formed; removing a portion of the primary bitumen froth from the primary separation vessel and recycling the portion of primary bitumen froth to that step of the process upstream of the primary separation vessel to join and mix with the feed stream moving to the primary separation vessel; and thereafter retaining said feed stream in said primary separation vessel to produce primary bitumen froth.

Abstract: A method and apparatus for recovering bitumen as froth from a feed stream having solids, water and bitumen is provided using a separating vessel having mounted thereon a downpipe assembly, the downpipe assembly having at least one downpipe and a nozzle in fluid communication with each downpipe, for aerating a stream of middlings withdrawn from the separating vessel and reintroducing the aerated middlings back to the separating vessel.

Abstract: An improved low energy extraction process for recovering bitumen from oil sand whereby essentially all of the thermal energy input for processing the oil sand takes place at the slurry mixing step as opposed to at both the slurry mixing step and the slurry flooding step. Mined oil sand is mixed with sufficient hot slurry water to produce an oil sand slurry having a density in the preferred range of about 1.50 g/cc to about 1.60 g/cc and a temperature in the preferred range of about 40° C. to about 55° C., more preferably greater than about 43° C. The oil sand slurry is conditioned, preferably by pumping it through a pipeline for a sufficient length of time, and then flooded with cold flood water to produce a diluted slurry having a density in the range of about 1.4 g/cc to about 1.5 g/cc and a temperature generally below 40° C. and typically in the range of about 30° C. to about 35° C. The diluted slurry is introduced into a gravity separation vessel where bitumen froth is recovered.

Abstract: Average grade oil sand is mixed with water to produce a low temperature (20-35.degree. C.), dense (1.4-1.65 g/cc) slurry. The slurry is pumped through a pipeline for sufficient time to condition it. Air is injected into the slurry after the last pump. The slurry density is adjusted to about 1.5 g/cc by adding flood water near the end of the pipeline. The slurry is introduced into a primary separation vessel slurry as it is introduced into the (PSV), excess air is vented from the PSV and a hot water underwash is used to heat the froth produced. Slurry loading to the PSV is greater than about 4.78 tonnes of oil sand/hour/square meter to reduce velocity gradient in the fluid in the vessel. Bitumen froth is recovered. When fed low grade oil sand, the process is modified by adding flotation aid chemicals to the slurry in the pipeline and subjecting the PSV tailings and middlings to secondary recovery with agitation and aeration in a secondary separation vessel.