Method for producing steel

Claim 1

A METHOD FOR PRODUCING STEEL, COMPRISING THE STEPS OF: A. JACKET-HEATING A PLURALITY OF JACKETED SHAFT-FURNACE UNITS CONTAINING IRON ORE PELLETS; B. FLOWING A REDUCING GAS THROUGH THE PLURALITY OF JACKETHEATED SHAFT-FURNACE UNITS CONTAINING IRON ORE PELLETS, ALWAYS FROM A SHAFT-FURNACE UNIT CONTAINING IRON ORE PELLETS IN A MORE ADVANCED STAGE OF REDUCTION TO A SHAFTFURNACE UNIT CONTAINING IRON ORE PELLETS IN A LESS ADVANCED STAGE OF REDUCTION, BY FLOWING A FRESH REDUCING GAS THROUGH A FIRST UNIT CONTAINING IRON ORE PELLETS IN AN ADVANCED STAGE OF REDUCTION, FOR DIRECTLY REDUCING THE IRON ORE PELLETS WITH THE REDUCING GAS; AND WITHDRAWING THE REDUCING GAS FROM SAID FIRST UNIT AND FLOWING IT THROUGH A SECOND OF THE PLURALITY OF UNITS CONTAINING IRON ORE PELLETS IN A LESS ADVANCED STAGE OF REDUCTION THAN THE PELLETS IN SAID FIRST UNIT FOR EFFECTING A PRELIMINARY DIRECT REDUCTION OF THE PELLETS IN THE SECOND UNIT; C. WITHDRAWING PELLETS REDUCED TO COMPLETION FROM THE FIRST UNIT; D. PROTECTING THE WITHDRAWN PELLETS FROM THE FIRST UNIT WITH AT LEAST A PART OF SAID REDUCING GAS FROM THE LAST OF THE SHAFT-FURNACE UNITS THROUGH WHICH THE REDUCING GAS FLOWS; E. FEEDING THE WITHDRAWN PELLETS FROM THE FIRST UNIT AND PROTECTING REDUCING GAS TOGETHER INTO AN ELECTRIC FURNACE; F. INTRODUCING INTO THE FIRST UNIT NEW IRON ORE PELLETS WHICH ARE IN A LESS ADVANCED STAGE OF REDUCTION THAN THE IRON ORE PELLETS IN THE SECOND UNIT AND CHANGING THE DIRECTION OF FLOW OF THE FRESH REDUCING GAS SO THAT IT FLOWS INTO THE SECOND UNIT FOR BRINGING ABOUT COMPLETE DIRECT REDUCTION OF THE PRLIMINARILY REDUCED IRON ORE PELLETS IN THE SECOND UNIT AND THEN INTO THE FIRST UNIT TO EFFECT A PRELIMINARY DIRECT REDUCTION OF THE NEW IRON ORE PELLETS IN THE FIRST UNIT; G. WITHDRAWING PELLETS REDUCED TO COMPLETION FROM THE SECOND UNIT; H. PROTECTING THE WITHDRAWN PELLETS FROM THE SECOND UNIT WITH AT LEAST A PART OF SAID REDUCING GAS FROM THE LAST OF THE SHAFT-FURNACE UNITS THROUGH WHICH THE REDUCING GAS FLOWS; I. FEEDING THE WITHDRAWN PELLETS FROM THE SECOND UNIT AND PROTECTING REDUCING GAS TOGETHER INTO THE ELECTRIC FURNACE; J. INTRODUCING INTO THE SECOND UNIT NEW IRON ORE PELLETS WHICH ARE IN A LESS ADVANCED STAGE OF REDUCTION THAN THE IRON ORE PELLETS IN THE FIRST UNIT; AND K. AGAIN CHANGING THE DIRECTION OF FLOW OF THE FRESH REDUCING GAS SO THAT THE FRESH REDUCING GAS FLOWS INTO THE FIRST UNIT CONTAINING IRON ORE PELLETS THAT HAVE BEEN PRELIMINARILY REDUCED AND ARE READY FOR COMPLETE REDUCTION BY THE FRESH REDUCING GAS.

Claim 2

A METHOD FOR PRODUCING STEEL, COMPRISING THE STEPS OF: A. JACKET-HEATING A PLURALITY OF JACKETED SHAFT-FURNACE UNITS CONTAINING IRON ORE PELLETS; B. FLOWING A REDUCING GAS THROUGH THE PLURALITY OF JACKETHEATED SHAFT-FURNACE UNITS CONTAINING IRON ORE PELLETS, ALWAYS FROM A SHAFT-FURNACE UNIT CONTAINING IRON ORE PELLETS IN A MORE ADVANCED STAGE OF REDUCTION TO A SHAFTFURNACE UNIT CONTAINING IRON ORE PELLETS IN A LESS ADVANCED STAGE OF REDUCTION, BY FLOWING A FRESH REDUCING GAS THROUGH A FIRST UNIT CONTAINING IRON ORE PELLETS IN AN ADVANCED STAGE OF REDUCTION, FOR DIRECTLY REDUCING THE IRON ORE PELLETS WITH THE REDUCING GAS; AND WITHDRAWING THE REDUCING GAS FROM SAID FIRST UNIT AND FLOWING IT THROUGH A SECOND OF THE PLURALITY OF UNITS CONTAINING IRON ORE PELLETS IN A LESS ADVANCED STAGE OF REDUCTION THAN THE PELLETS IN SAID FIRST UNIT FOR EFFECTING A PRELIMINARY DIRECT REDUCTION OF THE PELLETS IN THE SECOND UNIT; C. WITHDRAWING PELLETS REDUCED TO COMPLETION FROM THE FIRST UNIT; D. PROTECTING THE WITHDRAWN PELLETS FROM THE FIRST UNIT WITH AT LEAST A PART OF SAID REDUCING GAS FROM THE LAST OF THE SHAFT-FURNACE UNITS THROUGH WHICH THE REDUCING GAS FLOWS; E. FEEDING THE WITHDRAWN PELLETS FROM THE FIRST UNIT AND PROTECTING REDUCING GAS TOGETHER INTO AN ELECTRIC FURNACE; F. INTRODUCING INTO THE FIRST UNIT NEW IRON ORE PELLETS WHICH ARE IN A LESS ADVANCED STAGE OF REDUCTION THAN THE IRON ORE PELLETS IN THE SECOND UNIT AND CHANGING THE DIRECTION OF FLOW OF THE FRESH REDUCING GAS SO THAT IT FLOWS INTO THE SECOND UNIT FOR BRINGING ABOUT COMPLETE DIRECT REDUCTION OF THE PRLIMINARILY REDUCED IRON ORE PELLETS IN THE SECOND UNIT AND THEN INTO THE FIRST UNIT TO EFFECT A PRELIMINARY DIRECT REDUCTION OF THE NEW IRON ORE PELLETS IN THE FIRST UNIT; G. WITHDRAWING PELLETS REDUCED TO COMPLETION FROM THE SECOND UNIT; H. PROTECTING THE WITHDRAWN PELLETS FROM THE SECOND UNIT WITH AT LEAST A PART OF SAID REDUCING GAS FROM THE LAST OF THE SHAFT-FURNACE UNITS THROUGH WHICH THE REDUCING GAS FLOWS; I. FEEDING THE WITHDRAWN PELLETS FROM THE SECOND UNIT AND PROTECTING REDUCING GAS TOGETHER INTO THE ELECTRIC FURNACE; J. INTRODUCING INTO THE SECOND UNIT NEW IRON ORE PELLETS WHICH ARE IN A LESS ADVANCED STAGE OF REDUCTION THAN THE IRON ORE PELLETS IN THE FIRST UNIT; AND K. AGAIN CHANGING THE DIRECTION OF FLOW OF THE FRESH REDUCING GAS SO THAT THE FRESH REDUCING GAS FLOWS INTO THE FIRST UNIT CONTAINING IRON ORE PELLETS THAT HAVE BEEN PRELIMINARILY REDUCED AND ARE READY FOR COMPLETE REDUCTION BY THE FRESH REDUCING GAS.