Abstract: Enhanced recovery of oil from an oil-containing particulate shale sludge is achieved by contacting the sludge with a light hydrocarbon solvent fraction, obtained from the processing of oil derived from the shale, in the presence of water to form an oil-solvent liquid phase which is separated from an aqueous phase containing oil-depleted shale. The oil-solvent liquid phase when introduced into a slurry of product oil and particulate contained within a shale retort provides several advantages, including lowering the viscosity of the product oil and enhanced separation of the product oil from the particulate shale.

Abstract: Low speed shutdown apparatus for a high temperature hammer mill having a relatively high speed drive motor connected to the hammer mill drive shaft includes a low speed, high torque shutdown drive motor and a drive belt for connecting the low speed shutdown motor to the hammer mill shaft in place of the high speed drive motor. Preferably both the high speed drive motor and the low speed shutdown motor are connected to the hammer mill shaft through electrically controlled clutches, an electrical control being provided for disengaging the high speed drive motor in the event of a shutdown situation in which the hammer mill is shutdown while loaded with hot material and for engaging the low speed motor with the shaft to keep the shaft turning so as to prevent or substantially eliminate warping of the shaft due to the high temperature in the mill while the mill cools down.

Abstract: Low speed shutdown apparatus for a high temperature hammer mill having a relatively high speed drive motor connected to the hammer mill drive shaft includes a low speed, high torque shutdown drive motor and a drive belt for connecting the low speed shutdown motor to the hammer mill shaft in place of the high speed drive motor. Preferably both the high speed drive motor and the low speed shutdown motor are connected to the hammer mill shaft through electrically controlled clutches, an electrical control being provided for disengaging the high speed drive motor in the event of a shutdown situation in which the hammer mill is shutdown while loaded with hot material and for engaging the low speed motor with the shaft to keep the shaft turning so as to prevent or substantially eliminate warping of the shaft due to the high temperature in the mill while the mill cools down.