Pelletizing iron ore concentrates

Claim 1

PROCESS OF INDURATING INITIALLYMOIST "GREEN" PELLETS OF FINELY DIVIDED MAGNETITE CONCENTRATES CONTAINING HOMOGENEOUSLY DISPERSED THERETHROUGH A SOLID CARBONACEOUS FUEL IN AN AMOUNT, WITHIN THE RANGE 0.5-1.25 PERCENT BY WEIGHT BASED ON THE DRY WEIGHT OR THE PELLERS, WHICH IS INSUFFICIENT TO CONTRIBUTE BY ITS COMBUSTION THE HEAT NECESSARY TO EFFECT THE DESIRED INDURATION, WHICH COMPRISES, CAUSING THE PELLETS AS A COLUMN GRAVITATIONALLY TO DESCEND THROUGH A SHAFT-TYPE INDURATIONG CHAMBER FORCING A CURRENT OF INITIALLY UNHEATED COOLING AIR TO TRAVERSE SAID COLUMN COUNTERCURRENTLY FROM BOTTOM TO TOP THEREOF, HEATING A CURRENT OF INITIALLY UNHEATED COMBUSTION AIR TO A TEMPERATURE IN EXCESS OF 2300* F BUT NOT ABOVE ABOUT 2550* F INTRODUCING THE CURRENT OF HEATED AIR INTO THE COLUMN OF PELLETS AT A LEVEL INTERMEDIATE ITS BOTTOM AND ITS TOP, CAUSING THE CURRENT OF HEATED AIR COUNTERCURRENTLY TO TRAVERSE THE UPPER PORTION OF THE COLUMN OF PELLETS MAINTAINING THE VOLUMN RATIO OF COOLING AIR COMBUS TION AIR WITHIN THE RANGE 7:3-11:9, THE TOTAL AIR USED BEING WITHIN THE RANGE 0.85-1.2 POUNDS PER 1 POUND OF PALLETS, DRY WEIGHT, AND SO ADJUSTING THE RATE OF DESCENT OF THE COLUMN OF PELLETS WITH RESPECT TO THE HEIGHT OF SAID UPPER PORTION OF THE COLUMN WHICH IS TRAVERSED BY SAID CURRENT OF BEATED AIR THAT A PELLET IS RESIDENT IN SAID UPPER PORTION FOR A TIME INTERVAL OF AT LEAST 40 MINUTES AND SUFFICIENT TO EFFECT SUSBTANTIAL GRAIN GROWTH AMONG IRON OXIDE PARTICLES.