Portland cement manufacture from oil shale

Claim 1

A PROCESS FOR MAKING CEMENT COMPRISING FORMING A FLOWABLE MIXTURE COMPRISING COARSE PARTICLES OF OIL SHALE IN A VAPORIZABLE LIQUID, SAID OIL SHALE CONTAINING COMBUSTIBLE ORGANIC MATERIAL AND SAID VAPORIZABLE LIQUID BEING CHARACTERIZED BY THE ABILITY TO EVAPORATE TO A VAPOR WHICH DOES NOT INTERFERE WITH THE COMBUSTION OF SAID COMBUSTIBLE ORGANIC MATERIAL IN SAID OIL SHALE; PASSING SAID MIXTURE THROUGH AN ELONGATED TUBULAR HEATING ZONE; HEATING SAID MIXTURE DURING PASSAGE THROUGH SAID TUBULAR ZONE TO A TEMPERATURE ABOVE THE BOILING POINT OF THE LIQUID COMPONENT OF SAID MIXTURE, THEREBY VAPORIZING SAID LIQUID COMPONENT AND FORMING A DISPERSION OF SOLID PARTICLES OF OIL SHALE IN RESULTING VAPOR; PASSING SAID DISPERISON THROUGH A SUCCEEDING ZONE OF HIGH VELOCITY FLOW WHILE SUBJECTING THE FLOWING STREAM THEREIN TO TURBULENCE AND A VELOCITY SUFFICIENT TO EFFECT DISINTEGRATION OF SAID IN MIXTURE WITH PARTICLES OF CALCAREOUS MATERIAL TO A SECOND HEATING ZONE; FIRING SAID MIXTURE AND CONVERTING THE ORGANIC CONTENT OF SAID OIL SHALE TO HYDROGEN AND CARBON MONOXIDE BY OXIDATION THEREOF IN SAID SECOND HEATING ZONE; SINTERING SAID PARTICLES AT LEAST PARTIALLY BY THE HEAT OF OXIDATION OF THE ORGANIC MATERIAL IN SAID OIL SHALE; AND DISCHARGING THE RESULTING CEMENT CLINKER FROM SAID SECOND HEATING ZONE.