A process for the separation and recovery of bitumen from dry tar sands or sands with negligible quantities of connate water. The process includes comminuting the tar sands to an average particle size of approximately one centimeter in diameter and digesting the comminuted tar sand in a hot, aqueous...http://www.google.es/patents/US4120776?utm_source=gb-gplus-sharePatente US4120776 - Separation of bitumen from dry tar sands
