Abstract: A system is provided for controlling the feed rate of material being loaded onto a conveyor train of variable configuration to prevent overloading. The system involves monitoring the power drawn by the various drive motors of the train to establish which is the limiting conveyor under prevailing operating conditions. The instantaneous weight of feed material loaded onto the conveyor train, at its input end, is continuously measured and the current average feed rate is computed from the instantaneous weights measured over a pre-set time interval. A rolling average of the total load to be carried by the limiting conveyor downstream is computed from the average feed rate, taking into account the length of the limiting conveyor. The feed rate is then adjusted in response to the computed rolling average to thereby avoid overloading the limiting conveyor and optimize loading of the conveyor train.

Abstract: The invention provides a process for extracting bitumen from oil sands. The process includes the step of conditioning the oil sands by adding hot water and steam to the oil sands. The conditioned oil sands are then introduced into a separation zone. Separation of the oil sands into a bitumen froth phase, a middlings phase and a tailings phase occurs in the separation zone. Water with air dissolved therein is continuously injected under pressure upwardly through the separation zone. The water is at a low temperature relative to the oil sands. At least two of the phases are then separately withdrawn from the separation zone.

Abstract: Oil containing sludges are treated for the recovery of oil therefrom to render the resultant sludge disposable, by a process of conditioning the sludge to destabilize the emulsified phase thereof, centrifuging the destabilized sludge to obtain a solids-rich material which is largely hydrocarbon free and disposable, and a supernatant, hydrocarbon-containing liquid, and then subjecting the supernatant so formed to liquid/liquid phase separation. The conditioning is conducted so as to prepare a conditioned sludge characterized by a solids content of less than 50% by weight, a water content of less than 90% by weight, an oil phase with an API gravity of less than 12.degree., a continuous aqueous phase, and the solids in the sludge being primarily water wetted, this conditioned sludge being ready for centrifugation.

Abstract: An improvement is provided to the known hot water process for extracting bitumen from mined oil sand. More particularly, a methodology is provided for the production of microbubbles of air, and it has been found that the so-produced microbubbles can be used in the primary flotation/settling step of the hot water process to yield increased bitumen recovery. More particularly, a steam stream and an air stream in admixture are injected via a submerged nozzle into a flowing aqueous stream. A plurality of finely dispersed microbubbles are formed. These microbubbles have a diameter less than about 100 microns. The stream of microbubbles is injected into the diluted aqueous tar sand slurry formed in the hot water process. The injection is practiced following the conditioning step and prior to the introduction of the slurry into the flotation/settling step.