EFFECT OF RETORTING CONDITIONS AND PORE STRUCTURE ON THE LEACHABILITY OF PROCESSED EASTERN OIL SHALE.

An extensive experimental study was conducted with two Eastern U. S. oil shales to establish the effects of retorting conditions on leachability and the changes in pore structure. The variables included particle size, heating rate, final retort temperature (400-600 degree C), and the type and velocity of sweep gas. Rapid heat up and vapor removal were found to enhance oil yield. Raw, retorted, and combusted shales were relatively nonporous, but surface areas did increase with retorting. Leachability of various heavy metals from raw and processed shales was studied in the pH range of 1 to 6. The retorting of oil shale in a hydrogen atmosphere resulted in enhanced leaching due to pyrite conversion to FeS.