Extraction of bitumen oils (tar) from tar sands

Abstract From the Canadian patent

A continuous process for the recovery of bitumen oils from tar sand comprises contacting tar sand with hot water in a contacting zone comprising a plurality of volumes connected in series providing an upper layer comprising hot water and a lower layer comprising tar sand in each volume, passing tar sand and hot water in countercurrent through the volumes from one to another repeatedly showering tar sand through the upper layer of hot water in each volume, recovering from a volume at one end of the series of volumes a liquid fraction rich in bitumen oils and from a volume at the other end of the series of volumes a slurry of sand that contains little or no bitumen oils. A froth suppression …