Process for producing hydraulic limes from oil shale

Claim 1

IN A PROCESS FOR PREPARING HYDRAULIC LIME BY HEAT TREATING AT ELEVATED TEMPERATURE A MIXTURE OF OIL SHALE AND MINERAL MATERIAL SAID MIXTURE CONTAINING LIMESTONE AND SOME SILICA AND ALUMINA, THE QUANTITIES OF THE COMPONENTS OF THE MIXTURE BEING REGULATED SO AS TO PRODUCE A HYDRAULIC LIME HAVING OPTIMUM STRENGTH CHARACTERISTICS, THE IMPROVEMENTS WHICH COMPRISE GRINDING OIL SHALE AND A MINERAL MATERIAL TO A PARTICLE SIZE OF LESS THAN 0.1 MM., TREATING THE FINELY GROUND OIL SHALE AND MINERAL MATERIAL TO FORM AN INTIMATE ADMIXTURE THEREOF, TREATING THE RESULTING ADMIXTURE TO FORM THEREFROM PELLETS HAVNG A DIAMETER OF FROM ABOUT 2 TO 10 MM., THEREAFTER FLUIDIZING SAID PELLETS AT AN ELEVATED TEMPERATURE USING AS FLUIDIZING GAS AN OXYGEN-CONTAINING GAS IGNITING THE FLUIDIZED PELLETS AND THEREBY COMBUSTING THE ORGANIC CONSTITUENTS OF THE OIL SHALE, AND RECOVERING THE HYDRAULIC LIME FREE OF ORGANIC CONSTITUENTS.