Method for reducing metal oxides

Claim 1

A METHOD FOR REDUCING METAL OXIDES WHICH COMPRISES: IN A FIRST REDUCTION TREATMENT, MIXING A STREAM COMPRISING AN OXYGEN-CONTAINING GAS MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 60*F. AND ABOUT 1800*F. AND A STREAM COMPRISING A PARTIALLY SPENT REDUCING GAS. SAID PARTIALLY SPENT REDUCING GAS BEING AN EFFLUENT OF AND CONVEYED FROM A SECOND REDUCTION TREAMTENT CONDUCTED SIMULTANEOUSLY WITH SAID FIRST REDUCTION TREATMENT AND MAINTAINED AT AN ELEVAGED TEMPERATURE FOR COMBUSTION WITH OXYGEN IN SAID OXYGEN-CONTAINING GAS, IN A MOL RATIO SUCH THAT THE MIXTURE IS HEATED TO A REDUCING TEMPERATURE, CONTACTING A MASS OF METAL OXIDE WITH THE RESULTING GASEOUS MIXTURE TO REDUCE A PORTION OF SAID METAL OXIDE; IN A SECOND REDUCTION TREATMENT, MIXING A STREAM COMPRISING AN OXYGEN-CONTAINING STREAM MAINTAINED AT A TEMPERATURE OF ABOUT 60*F. AND ABOUT 1800*F. AND A STREAM COMPRISING A REDUCING GAS SAID REDUCING GAS BEING AN EFFLUENT OF AND CONVEYED FROM A THIRD REDUCTION TREATMENT CONDUCTED SIMULTANEOUSLY WITH SAID SECOND REDUCTION TREATMENT AND MAINTAINED AT AN ELEVATED TEMPERATURE FOR COMBUSTION WITH OXYGEN IN SAID OXYGEN-CONTAINING GAS, THE MOL RATIO OF OXYGEN TO REDUCING GAS BEING GREATER THAN THAT EMPLOYED IN SAID FIRST REDUCTION TREATMENT SUCH THAT THE RESULTANT GASEOUS MIXTURE IS HEATED TO AN ELEVATED REDUCING TEMPERATURE, CONTACTING A MASS OF SAID PARTIALLY REDUCED METAL OXIDE FROM SAID FIRST REDUCTION TREATMENT WITH THE RESULTING GASEOUS MIXTURE TO FURTHER REDUCE A PORTION OF SAID METAL OXIDE TO THE METALLIC STATE; AND IN A THIRD REDUCTION TREATMENT CONTACTING A MASS OF SAID PARTIALLY REDUCED METAL OXIDE FROM SAID SECOND REDUCTION TREATMENT WITH A STREAM COMPRISING A REDUCING GAS TO REDUCE A FURTHER PORTION OF SAID PARTIALLY REDUCED METAL OXIDE TO THE METALLIC STATE.

Claim 2

A METHOD FOR REDUCING METAL OXIDES WHICH COMPRISES: IN A FIRST REDUCTION TREATMENT, MIXING A STREAM COMPRISING AN OXYGEN-CONTAINING GAS MAINTAINED AT A TEMPERATURE BETWEEN ABOUT 60*F. AND ABOUT 1800*F. AND A STREAM COMPRISING A PARTIALLY SPENT REDUCING GAS. SAID PARTIALLY SPENT REDUCING GAS BEING AN EFFLUENT OF AND CONVEYED FROM A SECOND REDUCTION TREAMTENT CONDUCTED SIMULTANEOUSLY WITH SAID FIRST REDUCTION TREATMENT AND MAINTAINED AT AN ELEVAGED TEMPERATURE FOR COMBUSTION WITH OXYGEN IN SAID OXYGEN-CONTAINING GAS, IN A MOL RATIO SUCH THAT THE MIXTURE IS HEATED TO A REDUCING TEMPERATURE, CONTACTING A MASS OF METAL OXIDE WITH THE RESULTING GASEOUS MIXTURE TO REDUCE A PORTION OF SAID METAL OXIDE; IN A SECOND REDUCTION TREATMENT, MIXING A STREAM COMPRISING AN OXYGEN-CONTAINING STREAM MAINTAINED AT A TEMPERATURE OF ABOUT 60*F. AND ABOUT 1800*F. AND A STREAM COMPRISING A REDUCING GAS SAID REDUCING GAS BEING AN EFFLUENT OF AND CONVEYED FROM A THIRD REDUCTION TREATMENT CONDUCTED SIMULTANEOUSLY WITH SAID SECOND REDUCTION TREATMENT AND MAINTAINED AT AN ELEVATED TEMPERATURE FOR COMBUSTION WITH OXYGEN IN SAID OXYGEN-CONTAINING GAS, THE MOL RATIO OF OXYGEN TO REDUCING GAS BEING GREATER THAN THAT EMPLOYED IN SAID FIRST REDUCTION TREATMENT SUCH THAT THE RESULTANT GASEOUS MIXTURE IS HEATED TO AN ELEVATED REDUCING TEMPERATURE, CONTACTING A MASS OF SAID PARTIALLY REDUCED METAL OXIDE FROM SAID FIRST REDUCTION TREATMENT WITH THE RESULTING GASEOUS MIXTURE TO FURTHER REDUCE A PORTION OF SAID METAL OXIDE TO THE METALLIC STATE; AND IN A THIRD REDUCTION TREATMENT CONTACTING A MASS OF SAID PARTIALLY REDUCED METAL OXIDE FROM SAID SECOND REDUCTION TREATMENT WITH A STREAM COMPRISING A REDUCING GAS TO REDUCE A FURTHER PORTION OF SAID PARTIALLY REDUCED METAL OXIDE TO THE METALLIC STATE.