Method of fluid bed roasting

Claim 1

THE METHOD OF SEPARATING INDIGENOUS CADMIUM, LEAD, ARSENIC, ANTIMONY, TIN, GERMANIUM AND MERCURY SULFIDE COMPONENTS FROM A FINELY-DIVIDED ZINC SULFIDE ORE CONCENTRATE IN A FLUID BED ROASTING OPERATION WHICH COMPRISES AGGLOMERATING THE ORE CONCENTRATE INTO DISCRETE PARTICLES RANGING IN SIZE BETWEEN 4 AND 65 MESH, CHARGING THE AGGLOMERATES TO THE UPPER PORTION OF A COLUMNAR FLUID BED OF THE DISCRETE PARTICLES MAINTAINING IN THE FLUIDIZED CONDITION SUBSTANTIALLY EXCLUSIVELY BY THE UPWARD FLOW OF GAS, INTRODUCING SULFIDE-ROASTING AIR INTO THE LOWER PORTION OF THE FLUID BED IN AMOUNT AT LEAST 5% IN EXCESS OF THAT THEORETICALLY REQUIRED TO COMBINE WITH THE ZINC SULFIDE COMPONENT OF THE CHARGE, INTRODUCING INTO THE UPPER PORTION OF THE FLUID BED BYT A SUBSTANTIAL DISTANCE BELOW THE UPPER SURFACE THEREOF AN AMOUNT OF FUEL GAS AT LEAST SUFFICIENT TO CONSUME SAID EXCESS OF SULFIDEROASTING AIR AND THUS PROVIDE AN ATMOSPHERE IN THE UPPER PORTION OF THE FLUID BED NON-OXIDIZING WITH RESPECT TO THE SULFIDES, THE SULFIDE-ROASTING AIR AND THE FUEL GAS PROVIDING THE PRINCIPAL SOURCE OF SAID FLUIDIZING GAS, MAINTAINING THE FLUID BED AT A TEMPERATURE OF AT LEAST ABOUT 900* C., DISCHARGING ROASTED ZINCIFEROUS PARTICLES FROM THE LOWER END OF THE FLUID BED AND WITHDRAWING FROM THE UPPER END OF THE FLUID BED ROASTER GASES CONTAINING THE SULFIDES VOLATILIZED FROM THE ZINC SULFIDE CHARGE.

Claim 2

THE METHOD OF SEPARATING INDIGENOUS CADMIUM, LEAD, ARSENIC, ANTIMONY, TIN, GERMANIUM AND MERCURY SULFIDE COMPONENTS FROM A FINELY-DIVIDED ZINC SULFIDE ORE CONCENTRATE IN A FLUID BED ROASTING OPERATION WHICH COMPRISES AGGLOMERATING THE ORE CONCENTRATE INTO DISCRETE PARTICLES RANGING IN SIZE BETWEEN 4 AND 65 MESH, CHARGING THE AGGLOMERATES TO THE UPPER PORTION OF A COLUMNAR FLUID BED OF THE DISCRETE PARTICLES MAINTAINING IN THE FLUIDIZED CONDITION SUBSTANTIALLY EXCLUSIVELY BY THE UPWARD FLOW OF GAS, INTRODUCING SULFIDE-ROASTING AIR INTO THE LOWER PORTION OF THE FLUID BED IN AMOUNT AT LEAST 5% IN EXCESS OF THAT THEORETICALLY REQUIRED TO COMBINE WITH THE ZINC SULFIDE COMPONENT OF THE CHARGE, INTRODUCING INTO THE UPPER PORTION OF THE FLUID BED BYT A SUBSTANTIAL DISTANCE BELOW THE UPPER SURFACE THEREOF AN AMOUNT OF FUEL GAS AT LEAST SUFFICIENT TO CONSUME SAID EXCESS OF SULFIDEROASTING AIR AND THUS PROVIDE AN ATMOSPHERE IN THE UPPER PORTION OF THE FLUID BED NON-OXIDIZING WITH RESPECT TO THE SULFIDES, THE SULFIDE-ROASTING AIR AND THE FUEL GAS PROVIDING THE PRINCIPAL SOURCE OF SAID FLUIDIZING GAS, MAINTAINING THE FLUID BED AT A TEMPERATURE OF AT LEAST ABOUT 900* C., DISCHARGING ROASTED ZINCIFEROUS PARTICLES FROM THE LOWER END OF THE FLUID BED AND WITHDRAWING FROM THE UPPER END OF THE FLUID BED ROASTER GASES CONTAINING THE SULFIDES VOLATILIZED FROM THE ZINC SULFIDE CHARGE.