Endothermic reduction of iron oxide

Claim 1

I THE ENDOTHERMIC REDUCTION OF IRON OXIDE IN THE FORM OF SOLID PARTICLES BY REACTION WITH HIGH-PURITY HYDROGEN TO FORM A SUBSTANTIAL AMOUNT OF FREE IRON, WHILE A BED OF SAID PARTICLES IS MAINTAINED IN A MOBLIALZED CONDITION, SAID BED HAVING AN UPPER LEVEL FROM WHICH REACTION GASES LEAVE SAID BED, AND SAID HIGH-PURITY HYDROGEN CONTAINING NOT MORE THAN A MINOR AMOUNT OF CARBON OXIDES, METHANE, NITROGEN, ARGON AND WATER VAPOR AND INITIALLY HAVING A COMPOSITE AVERAGE MOLECULAR WEIGHT NOT EXCEEDING 10, THE IMPROVEMENT OF SUPPLYING BENT TO SAID BED WHICH COMPRISES PASSING SAID HIGH-PURITY HYDROGEN, PREHEATED TO A TEMPERATURE ABOVE THAT AT WHICH SAID PARTICLES AGGLOMERATE, IN INDIRECT HEAT EXCHANGE RELATION WITH SAID BED TO SUPPLY HEAT THERTO AND COOL SAID HIGH-PURITY HYDROGEN, AND BRING SAID HIGH-PURITY HYDROGEN INTO REACTING CONTACT WITH SAID BED AFTER SAID HIGH-PURITY HYDROGEN HAS BEEN COOLED TO A TEMPERATURE BELOW THAT AT WHICH SAID PARTICLES AGGLOMERATE.