Abstract: A method for separating and recovering bitumen from tar sand and other viscous petroleum deposits, either in situ or after mining the deposits. The method may also apply to heavy oil wells and to secondary and tertiary recovery of oils from wells. The tar sand is heated in an aqueous mixture of floating agent containing ammonia, a transfer agent containing a phosphate or silicate ion and a strong monovalent base. The bitumen rises to the surface of the mixture, without foaming or appreciable emulsification and will stay at the surface after cooling. Nearly clean sand remains in the bottom. Both an in situ separation technique and a process for recovering bitumen from mined tar sand are described using the aqueous mixture.