Abstract: Bitumen, floating on tailings pond water in the form of a cohesive blanket, is recovered from the surface by an apparatus that takes advantage of the cohesiveness of the bitumen. A drum with radially attached prongs is partly submerged in the water and is rotated around its longitudinal axis so that the prongs penetrate into the bitumen blanket and grip and pull it towards the drum. Upon being drawn by the prongs beneath the surface of the water, hydrostatic pressure causes the bitumen to adhere to the curved surface of the drum. During the upswing of the drum, the prongs and the adhesiveness of the metal surface of the drum hold the bitumen on the drum. A comb scraper then removes the greater portion of the bitumen, which falls into a receptacle.

Abstract: The invention provides a method and apparatus for sampling a frozen core of tar sand. The frozen core is first cut transversely along its length to form a pair of slabs of semi-circular cross-section. A longitudinal sample portion of substantially triangular cross-section is then cut from the central portion of the still frozen slab. The triangular sample portion is ground in a cryogenic grinder to produce a finely divided, substantially homogeneous material from which small representative sub-samples may be obtained. The triangular sample portion is cut from the slab by a pair of angularly disposed circular saws carried along the length of the slab. The slab is supported and held by cradle means which fix the flat face of the slab in a predetermined plane. The longitudinal sample portion thus formed has a triangular cross-section of substantially constant cross-sectional area.

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: The hot water extraction process for recovering bitumen from tar sand produces a large volume of solids-laden aqueous tailings as a waste product. The solids in the tailings stream may be flocculated by the addition of time and the components of the stream then separated into a water-free solids phase and a clarified water phase. During flocculation, the zeta potential of the stream is monitored. It rises from an initial negative zeta potential, as the lime is added. Flocculation is terminated when the zeta potential is about zero. At this point, the tailings are in optimum condition for separation into the water-free solids phase and the clarified water phase. Separation is preferably effected by vacuum filtration.

Abstract: Whole tailings are treated with a flocculant to cause fines to agglomerate with the coarse particles. The product is then vacuum filtered to separate the fines from the water.

Abstract: The titanium and zirconium-based minerals, present in the first stage centrifuge tailings from the hot water process for extraction of bitumen from bituminous sands, may be concentrated by a dry screening process. The tailings are burned off to provide a dry, essentially carbon-free, mineral mixture. By screening the mixture into three streams of different particle size range, silica and clays may be rejected as coarse and fine materials respectively, while titanium and zirconium minerals may be concentrated in the intermediate stream. The titanium and zirconium concentrate stream may be advanced to high tension and magnetic separation steps known in conventional processing of heavy minerals, for further beneficiation.

Abstract: To optimize recovery by the hot water process of hydrocarbons from bituminous sands, an alkaline process aid (e.g. NaOH) is commonly added to the conditioning step. In accordance with this invention, the quantity of process aid added is varied in response to the fines content of the incoming bituminous sands feed.

Abstract: An aqueous solution suspension or emulsion containing a water-soluble or oil-soluble non-ionic emulsifying agent is useful, when spread over the load-bearing surface of a conveyor carrying bituminous sands, to act as a release agent to promote the clean separation of the tacky sands from the belt when the latter rounds the end roller of the conveyor system and unloads the sands.

Abstract: A process for treating a conveyor belt carrying bituminous sands with a release agent comprises: applying to the sands-bearing surface of the belt, prior to deposition of the bituminous sands, a water-based emulsion having as the disperse phase a silicone fluid having short hydroxyl-terminated polymer chains and a viscosity on the order of 100 centistokes; unloading the sands from the belt; and recovering the bitumen from the sands using a hot water extraction step. The emulsion acts as a release agent which effects clean separation of the sands from the belt surface during unloading and does not deleteriously affect the primary bitumen recovery in the extraction step.

Abstract: It has been found that tank-type air flotation cells are more efficient, when treating hot water process middlings containing in excess of about 3% bitumen, than trough-type air flotation cells. Also, it has been found that the trough-type cells are more efficient than the tank-type cells when treating middlings containing less than about 3% bitumen. Thus a secondary recovery circuit is proposed wherein the middlings are first treated in one or more tank-type cells in series and the underflow from the last tank-type cell is treated in one or more banks of trough-type cells.

Abstract: An oily mass of solids tailings is derived from flotation of bitumen during hot water extraction of bituminous sands, and subsequent separation of most of the bitumen from associated solids. This oily mass contains a high concentration of heavy minerals, in the order of 10% by weight titanium and 4% zirconium. The tailings are introduced into a hot reaction zone and contacted with oxygen while agitating the solids. The bitumen associated with the solids is burned, as is residual coke left from the combustion of the bitumen. The product particles are discrete, dry and clean. They can be slurried with water and passed through gravity concentrating means, such as a spiral, to produce a concentrate containing in the order of 18% titanium and 8% zirconium.

Abstract: An emulsion of bitumen in sodium hydroxide solution containing at least 1 wt. % bitumen as the disperse phase is useful, when spread over the load-bearing surface of a conveyor carrying bituminous sands, to act as a release agent to promote the clean separation of the tacky sands from the belt when the latter rounds the end roller of the conveyor system and unloads the sands.

Abstract: An oily mass of solids tailings is derived from flotation of bitumen during hot water extraction of bituminous sands, and subsequent separation of most of the bitumen from associated solids. This oily mass contains a high concentration of heavy minerals, in the order of 10% by weight titanium and 4% zirconium. The tailings are introduced into a hot reaction zone and contacted with oxygen while agitating the solids. The bitumen associated with the solids is burned, as is residual coke left from the combustion of the bitumen. The product particles are discrete, dry and clean. They can be slurried with water and passed through gravity concentrating means, such as a spiral, to produce a concentrate containing in the order of 18% titanium and 8% zirconium.

Abstract: In the hot water process wherein tar sand is slurried in a tumbler with hot water and sodium hydroxide, oversized material, rejected from the tumbler, is mixed with a portion of slurry flood water in a second slurrying device and subjected therein to heating and dispersal of bitumen associated with the rejects. A bitumen-containing slurry is produced from the second device and this slurry is combined with the tumbler slurry and subsequently subjected to flotation to recover bitumen.

Abstract: Bitumen froth streamsfrom the primary separation vessel and secondary flotation cells are gravity transferred into one or more columns and heated and deaerated therein by passing them countercurrent to steam. The heated deaerated froth is then pumped with centrifugal pump means to the froth treatment circuit. By deaerating and heating before pumping, the froth is converted from a form difficult to pump to one which is relatively easy to pump.

Abstract: It has been found that controlling the rate of withdrawal of tailings from a hot water process primary separation vessel with a rake torque sensor is attended by problems when the feed to the vessel is high in fine solids content. It was also found that a nuclear density gauge was much better at controlling the withdrawal with the high fines feed, but did not work as well as rake torque control with low fines feed. Therefore the withdrawal is now controlled with a rake torque sensor when the vessel is receiving low fines feed and a density gauge when it is receiving high fines feed.

Abstract: For operating control and safety, a variable-speed close-coupled pump is direct connected to the underflow of the primary separation vessel (PSV). The desired discharge density of the PSV is 70- 80% solids in order to minimize bitumen losses. For a good pumping system, the pump discharge density should be less than 65% solids to avoid settling out of the solids in the downstream conduit. Therefore it is necessary to dilute the PSV underflow before it reaches the pump. Secondary flotation tailings, a dilute stream containing a high proportion of fine solids, is used for this purpose. The solids content of the PSV underflow is monitored by one of two alternative systems-- a torque recorder on the PSV rake shaft or a density gauge on the PSV underflow conduit. The former is used when the PSV is being fed low fines tar sand-- the latter when it is treating high fines tar sand. The close-coupled pump speed is adjusted relative to the solids content measurement to keep it at the desired 70- 80% level.

Abstract: Ozone is dispersed in river water to be purified and used in a high pressure boiler. The ozone selectively degrades large organic molecules, dissolved in the water, which ordinarily will irreversibly foul the strongly basic anion attracting resin used to adsorb silicious contaminants from the water. The degraded molecules are reduced in resin-fouling capability and are removed from the resin during regeneration.

Abstract: Coked solids, produced by coking of tar sands, are contacted in a first zone with air and the minimum amount of supplemental fuel needed to burn all the coke. Part of the hot clean mineral solids produced is then discarded; the balance is moved into a second zone. Here supplemental fuel is burned to increase the temperature of the solids. The hot solids from the second zone are recycled to the coking stage.Only part of the solids is heated with supplemental fuel, thereby reducing consumption of the latter. In addition, the flue gas from the second zone is relatively clean and can be vented directly to the atmosphere in the flue gas from the first zone.