Method for extracting an oil content from oil shale

A method for extracting oil from oil shale consisting essentially of pulverizing oil shale into powder and applying ultrasonic waves to the powdery grains, while at the same time applying pressure to said grains;

• said ultrasonic waves imparting such vibration to the powdery oil shale grains so as to generate heat both on the grain boundaries and by intermolecular excitation of the molecules in the powdery grains, said heat being sufficient to extract the oil from the oil shale in both a liquid and gaseous form, said liquid oil being squeezed out of the oil shale by applying sufficient pressure to effect such removal of the oil;
• and recovering the oil extracted from the shale oil.