Separation and recovery of heat carriers in an oil shale retorting process

摘要

In an oil shale retorting process, hot heat-carrying spherically-shaped solids are cycled to a retort zone to mix with and retort crushed oil shale, thereby producing gas and oil products and a mixture of irregularly-shaped, laminar spent shale and spherically-shaped solids. The spherically-shaped solids are separated and recovered from the spent shale for recycle through the process. In one stage of the separation procedure, a mixture of spent shale and spherically-shaped solids is fed to a continuously restored inclined surface whereon the spherically-shaped solids roll from the surface while the irregularly-shaped spent shale solids are separately removed from the inclined surface. Continuous restoration of the inclined surface is achieved through movement of the feed and the impingement area of the inclined surface relative to each other. The separation system may be used for separating other types of spherically-shaped solids which will roll from nonspherical, irregularly-shaped solids which do not roll.