Production of sodium chromate from chromite ores

Claim 1

THE PROCESS OF PRODUCING SODIUM CHROMATE FROM CHROMINIUM ORES CONTAINING AT LEAST 40% CR2O3 WHICH PROCESS COMPRISES MIXING POWERED ORE, HYDRATED LIME FROM THE GROUP CONSISTING OF NON-DOLOMITIC AND DOLOMITIC LIME, SODA ASH AND WATER IN THE PROPORTIONS OF FROM 60 TO 80 PARTS OF HYDRATED NON-DOLOMITIC LIME WHEN USING THE LATTER AND 75 TO 115 PARTS OF HYDRATED DOLOMITIC LINE WHEN USING HYDRATED DOLOMITIC LIME, 50 TO 70 PARTS WATER AMOUNT OF SODA ASH REQUIRED TO REACT WITH THE CHROMIUM CONTENT OF THE ORE TO PRODUCE SODIUM CHROMATE, PELLETING SAID MIXTURE TO PRODUCE SMALL PELLETS, EACH OF SAID SMALL PELLETS CONTAINING SUBSTANTIALLY THE SAME RELATIVE PROPORTIONS OF THE HYDRATED LIME, WATER, SODA ASH AND POWDERED ORE AS IN THE MIXTURE SUBJECTED TO PELLETING, WITH THE POWDERED ORE PARTICLES DISPERSED SUBSTANTIALLY UNIFORMLY RELATIVE TO THE OTHER CONSTITUENTS WITHIN EACH PELLET, HEATING SAID PELLETS TO A TEMPERATURE OF FROM 900* TO 1100*F. TO PRODUCE STRONG, HARD PELLETS, ROASTING SAID RESULTING HARD PELLETS BY PASSING THEM THROUGH AN OXIDIZING ATMOSPHERE VARYING IN TEMPERATURE FROM 1000*F. TO 1500*F. AT THE PELLET-INLET END TO FORM ABOUT 2000*F. TO 200*F. AT THE PELLET-EXIT END OF SAID OXIDIZING ATMOSPHERE ANE LEACHING THE THUS ROASTED PELLETS TO REMOVE THE SODIUM CHROMATE THEREFROM.