Treating arsenical gold ores

Claim 1

THE CONTINUOUS PROCESS FOR ROASTING FINELYDIVIDED GOLD-BEARING ARSENOPYRITE SOLIDS TO RENDER THEIR GOLD VALUES AMENABLE TO CYANIDATION WITH MINIMUM CYANIDE CONSUMPTION, COMPRISING THE STEPS OF ESTABLISHING AND MAINTAINING A FLUIDIZED TREATMENT BED OF SUCH SOLIDS IN A PRIMARY TREATMENT ZONE BY FEEDING SOLIDS THERETO AND PASSING THERETHROUGH AT SOLIDS FLUIDIZING VELOCITIES AN UPRISING STREAM OF FREE-OXYGEN BEARING GAS WHILE MAINTAINING THE SOLIDS AT ROASTING TEMPERATURES LESS THAN FUSION TEMPERATURES, AND UNDER SUCH CONDITIONS EFFECTING SUBSTANTIAL REMOVAL OF ARSENIC AS VOLATILE ARSENIC COMPOUNDS TO YIELD PARTIALLY ROASTED ARSENIC-FREE SOLIFS BY REGULATING THE QUANTITY OF FREE-OXYGEN IN THE UPRISING GAS STREAM TO BE AN AMOUNT SUFFICIENT TO OXIDIZE A PORTION OF THE SULFIDE-SULFUR CONTENT OF THE SOLIDS TO SULFUR-DIOXIDE BUT INSUFFICIENT TO SO OXIDIZE ALL OF SUCH SULFUR, DISCHARGING GASES INCLUDING VOLATILE ARSENIC COMPOUNDS FROM THE BED AND FROM THE ZONE, DISCHARGING PARTIALLY ROASTED ARSENIC-FREE SOLIDS FROM THE PRIMARY ZONE TO A SECONDARY ZONE TO ESTABLISH IN THE LATTER ZONE A BED OF SUCH SOLIDS, TREATING SOLIDS OF THE LATTER BED UNDER SOLIDS FLUIDIZING CONDITIONS TO YIELD SUBSTANTIALLY COMPLETELY ROASTED SOLIDS BY MAINTAINING THE BED AT ROASTING TEMPERATURES LESS THAN FUSION TEMPERATURES WHILE PASSING THERETHROUGH AT SOLIDS FLUIDIZING VELOCITIES AN UPRISING STREAM OF GAS INITIALLY CONTAINING FREE-OXYGEN IN AN AMOUNT AT LEAST SUFFICIENT TO SUBSTANTIALLY OXIDIZE ALL RESIDUAL UNOXIDIZABLE CONSTITUENTS OF THE BED SOLIDS, DISCHARGING GASES FROM THE ZONE, AND DISCHARGING SUBSTANTIALLY OXIDIZED ARSENICFREE SOLIDS FROM THE ZONE.