a method for separating bitumen from tar sand by solvent extraction with efficient separation of water from the recovered bitumen is disclosed . tar sand may often be recovered by surface mining techniques . the tar sand is comprised of bitumen , water and sand including clays . the tar sand is contacted with bitumen solvent having a freezing point below that of the water , and the temperature of the mixture is lowered below the freezing point of the water in the tar sand . the solid ice crystals may then be easily removed along with the sand leaving a water - free liquid bitumen solvent mixture .