A system for recovering hydrocarbons from tar sands includes a heated enclosure 66, one or more input conveyors 60, 67 move tar sands through the heated enclosure, provide a flow line with a temperature gradient of at least 150° F., and mechanically move the tar sands along the flow line. A heated rotary drum 74 is in fluid communication with the flow line, and condenser unit 94, 98 receive vapors from the flow line and the rotary drum and output hydrocarbons. One or more discharge conveyors 76 discharge stripped sands from the rotary drum. Control valves 80, 82 seal a vacuum downstream from the discharge conveyors, and control valves 34, 46 seal vacuum upstream from the one or more input conveyors. Various types of vacuum pumps may be used to maintain a selected vacuum between the control valves.