Methods for the reduction and sintering of bodies containing reducible metal compounds

Claim 1

IN A PROCESS FOR PRODUCING AN ARTICLE OF PREDETERMINED SHAPE FROM POWDERED MATERIAL CONSISTING ESSENTIALLY OF FE2O3, THE STEPS COMPRISING COMPACTING SAID POWDERED MATERIAL AT A PRESSURE OF NOT OVER ABOUT 3 TONS PER SQUARE CENTIMETER INTO A BODY HAVING SUBSTANTIALLY THE SHAPE OF THE ARTICLE TO BE PRODUCED, HEATING THE COMPACTED BODY AT A RATE NOT EXCEEDING 5* C. PER MINUTE TO A TEMPERATURE OF ABOUT 600* C. IN AN ATMOSPHERE CONSISTING ESSENTIALLY OF A REDUCING ATMOSPHERE, AND MAINTAINING IT AT SAID TEMPERATURE FOR A SUFFICIENT LENGTH OF TIME FOR A SUBSTANTIAL PART OF THE GAS EVOLVED AT SAID TEMPERATURE TO ESCAPE DURING THE REDUCTION OF THE VALENCY INVOLVED WITHOUT CAUSING CRACKS IN THE BODY, AND THEN HEATING TO A TEMPERATURE IN THE RANGE OF 1000 TO 1250* C. IN AN ATMOSPHERE CONSISTING ESSENTIALLY OF A REDUCING ATMOSPHERE FOR A SUFFICIENT LENGTH OF TIME TO COMPLETE THE REDUCTION OF THE OXIDE AND FOR AT LEAST PRESINTERING TO TAKE PLACE.