Fluid retorting process

Claim 1

IN A PROCESS FOR RETORTING PARTICULATE OIL-BEARING SOLIDS TO RECOVER THEREFROM VALUABLE HYDROCARBONS VAPORS BY SUBJECTING SAID SOILIDS TO RETORTING TEMPERATURES IN A DENSE, TURBULENT BED OF SOLIDS STABLY FLUIDFIZED BY AN UPWARDLY FLOWING GAS IN A RETORTING ZONE, THE STEPS COMPRISING FEEDING SOLID PARTICLES OF RAW OIL-BEARING MINERALS TO SAID ZONE, SAID FEED CONTAINING APPRECIABLE MEMBERS OF PARTICLES OF SUCH SIZE THAT THE ARE INCAPABLE BY THEMSELVES OF BEING STABLY FLUIDIZED AT THE GAS RATE EMPLOYED IN SAID ZONE; SEPARATELY WITHDRAWING THE LARGER RETORTED BING PARTICLES FROM AN ELUTRIATION SECTION OF SAID RETORTING ZONE; WITHDRAWING THE REMAINING RETORTED BING FROM SAID RETORTING ZONE AND PASSING IT ALONG WITH AN OXYGEN-CONTAINING GAS INTO A COMBUSTION ZONE, SAID OXYGEN-CONTAINING GAS BEING INTRODUCED INTO THE LATTER ZONE AT A RATE SUFFICIENT TO MAINTAIN THE RETORTED BING IN A STABLE FLUIDIZED CONDITION WITHIN SAID COMBUSTION ZONE; BURNING THE COMBUSTIBLES ASSOCIATED WITH THE RETORTED BING IN SAID