Process of manufacturing pigment zinc oxide

Claim 1

THE PROCESS OF MANUFACTURING PIGMENT ZINC OXIDE WHICH COMPRISES MAINTAINING A BODY OF COMMINUTED ZINCIFEROUS MATERIAL IN A FLUIDIZED BED BY PASSING CURRENT OF MIXED HYDROCARBON GAS AND AIR THROUGH SAID BED, CONTINUOUSLY ADDING ZINCIFEROUS MATERIAL TO SAID FLUIDIZED BODY IN PARTICLE SIZE NO COARSER THAN 10 MESH AND 70% COARSER THAN 325 MESH, SAID CURRENT OF MIXED HYDROCARBON GAS HAVING A VERTICAL VELOCITY THROUGH SAID BED OF FROM ONE TO FIVE FEET PER SECOND AT REACTOR TEMPERATURES, ALTERNATELY INCREASING AND DECREASING THE AIR-HYDROCARBON GAS RATIO TO FIRST PRODUCE A RAPID HEATING CONDITION IN SAID BODY OF ZINCIFFEROUS MATERIAL AND THEN TO PRODUCE A STRONGLY REDUCING CONDITION THEREIN, SAID ALTERNATIONS BEING SO TIMED AND RANGING FROM APPROXIMATELY 5 TO 21/2 MINUTES THAT THE TEMPERATURE WITHIN SAID MATERIAL DOES NOT FALL BELOW 1100* C. AND DOES NOT EXCEED 1300* C. , REMOVING THE EVOLVED ELEMENTAL ZINC CONTAINING VAPORS OBTAINED DURING THE REDUCING CYCLES FROM THE FLUIDIZED MATERIAL, AND MIXING AIR WITH SAID ZINC VAPORS TO OXIDIZE SAID VAPORS TO ZINC OXIDE.