Roasting sulfide ores

Claim 1

A PROCESS FOR ROASTING A METAL SULFIDE WHICH LIBERATES SULFUR ON HEATING WHICH COMPRISES SUSPENDING THE SULFIDE IN FINELY DIVIDED FORM IN A ZONE IN AN UPFLOWING STREAM OF OXIDIZING GAS HAVING A VELOCITY SUCH AS TO MAINTAIN THE SULFIDE IN A DENSE FLUIDIZED SUSPENSION, REGULATING THE TEMPERATURE AND THE OXIDIZING CHARACTER OF THE UPFLOWING GAS IN SAID ZONE SO AS TO INSURE THE FORMATION OF A MINOR AMOUNT OF METAL OXIDE IN SAID ZONE WHEREBY SULFUR IS LIBERATED FROM SAID SULFIDE, REMOVING SAID LIBERATED SULFUR FROM SAID DISTILLATION ZONE IN SAID STREAM OF GAS, SEPARATELY REMOVING FINELY DIVIDED SOLID FROM SAID ZONE, BURNING SAID REMOVED SULFUR UNDER CONTROLLED CONDITIONS TO PRODUCE A MINIMUM OF SO3, COMBINING THE COMBUSTION GAS SO PRODUCED WITH THE FINELY DIVIDED SOLID REMOVED FROM SAID ZONE, FEEDING THE MIXTURE TO A ROASTING ZONE, MAINTAINING THE FINELY DIVIDED SOLID IN SAID ROASTING ZONE IN THE FORM OF A DENSE, FLUIDIZED MIXTURE IN AN UPFLOWING STREAM OF OXIDIZING GAS, ADJUSTING THE TEMPERATURE, THE OXIDIZING CHARACTER OF THE GAS AND THE SOLID CONTENT IN SAID ROASTING ZONE