Proposals have been made to recover bitumen from oil sand deposits occurring between 500 and 2,000 feet below ground level in the Athabasca region of Alberta, Canada by the utilization of steam to render the bitumen flowable and the removal of the bitumen from the deposit in suspension in hot water (about 180.degree. to 200.degree. F.) under the influence of the steam pressure. After separation of the bitumen from the aqueous phase there is left "brackish water" which contains considerable mineral concentrations and also residual hydrocarbons.
Both of the contaminants inhibit reutilization of the brackish water for steam production, which is required to be produced at about 1,500 to 2,000 psi, since the minerals scale the reboiler tubes and the hydrocarbons cause fouling of boiler parts. The volume of water required for steam extraction is substantial, amounting to approximately 3 to 9 barrels of water per barrel of bitumen recovered. The inability to utilize the brackish water for steam regeneration imposes a considerable strain on the limited water resources of the region and also poses a considerable disposal problem.