Production of metals

Claim 1

THE PROCESS OF MANUFACTURING HIGH PURITY IRON AND ALLOYS OF IRON HAVING AN OXYGEN CONTENT BY WEIGHT OF LESS THAN ABOUT 0.015% AND A CARBON CONTENT BY WEIGHT OF LESS THAN ABOUT 0.005%, SAID PROCESS COMPRISING THE STEPS OF CONFINING SAID IRON IN A VACUUM FURNACE IN A CRUCIBLE PREDOMINATING IN AN OXIDE OF A METAL HAVING A HIGH VAPOR PRESSURE AT THE TEMPERATURE OF MOLTEN IRON, ADDING TO SAID IRON, AT SOME STAGE IN SAID PROCESS, AN AMOUNT OF CARBON IN EXCESS OF THE AMOUNT NEEDED FOR STOICHIOMERTRICALLY REACTING WITH THE OXYGEN IN SAID IRON , EVACUATING SAID FURNACE, HEATING SAID IRON AND CARBON TO A TEMPERATURE ON THE ORDER OF ABOUT 1650*C., MAINTAINING SAID TEMPERATURE TURE SUBSTANTIALLY CONSTANT, MEASURING THE RATE OF EVOLUFROM REDUCTION OF IRON OXIDE BY SAID ADDED CARBON, AND POURING SAID IRON INTO MOLD BETWEEN THE TIME WHEN THE CARBON MONOXIDE EVOLUTION RATE FALLS TO ABOUT 20 MICRON CUBIC FEET PER MINUTE PER POUND OF IRON AND BEFORE THE CARBON MONOXIDE EVOLUTION RATE FALLS TO ABOUT 4 MICRON CUBIC FEET PER MINUTE PER POUND OF IRON.