Feeding a slurry comprising inert solids, liquid hydrocarbons, liquid water and sometimes dissolves solids to a unit having a casing defining a thermal extraction chamber heated both directly and indirectly in which first and second intermeshing screws rotate, the screws in close tolerance with each other and with inside casing surfaces. The casing and screws define a tortuous flow path in which the slurry and a vaporous composition evolved therefrom flow. The intermeshing screws push the slurry toward a discharge end of the chamber at a first velocity while reducing pressure and increasing temperature in the chamber, while rotating the screws to create turbulent vacuum thermal conditions in the chamber to physically transform some or all of the slurry into the vaporous composition. The vaporous composition traverses the tortuous flow path with a second velocity at least 1.5 times the first velocity, optionally forming a heated, substantially dry, composition comprising the inert solids.