DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
The amendment filed on 08/07/2026 has been entered. Claim(s) 1-20 is/are pending in the application. Applicant’s amendments to the claims have overcome each and every objection and/or 112(b) rejection previously set forth in the office action mailed 05/12/2026.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1 is/are rejected under 35 U.S.C. 102((a)(1)) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Bueno et al. (US6395055B1).
Regarding Claim 1, Bueno teaches s process for direct reduction of iron ore to sponge iron, (direct reduction of mineral iron, See Abstract)
wherein the iron ore passes through a reduction zone for reducing the iron ore to sponge iron (reduction reactor, Col. 2, Lines 5-10)
wherein the reduction zone is subdivided into a pre-reduction zone 12 (first stage) supplied with a first reduction gas 17 (Col. 2, Lines 10-19)
and into an end-reduction zone 14 supplied with a second reduction gas 18 (Col. 2, Lines 20-28) (See Fig 1)
wherein the first reduction gas has a different gas composition compared to the second reduction gas as the gas moves up from the first reduction zone to the second where the reaction in the bottom section forms a “high content of H2 and CO” (Col. 2, Lines 40-55); one of ordinary skill in the art would expect a significant difference in hydrogen volume from one section to the other to represent the “high” formation of hydrogen, more than the claimed 5% volume difference; alternatively on of ordinary skill in the art would have been motivated to ensure final conversion in the second region is as high as possible, forming as much hydrogen as possible including the claimed difference for the purpose of forming as much reduced Fe in the reaction Fe+CH4=Fe+2H2+CO as taught by the prior art.
Claim(s) 2-12, 15-16 is/are rejected under 35 U.S.C. 103 as obvious over Bueno et al. (US6395055B1) in view of Boehm et al. (US20210246521A1).
Regarding claims 2-3 and 15, Bueno teaches injecting mixing gases by controlling percentages of reducing gas in the two zones of the furnace (See claim 9) where a first and second gas inlets may be supplied into the respective zones (Col. 5, Lines 14-20); the reducing gas of stage one (pre-reduction zone) are a mixture of CO and H2 (Col. 6, Lines 10-16); however, the prior art does not teach or suggest the reduction gas mixture consists only of hydrogen. However, Boehm teaches direct reduction of iron oxide material to iron sponge may be done with a reduction gas consisting at least predominantly of H2 (Abstract); therefore, one of ordinary skill in the art would have been motivated to modify at least the reduction gas mixture of the first stage with a reducing gas consisting of hydrogen as a substitution of one well known reduction gas for DRI with another to predictably reduce iron oxide.
Regarding claim 15, a mixture consisting of hydrogen reads on at least 95% vol; while Bueno teaches methane (natural gas, CH4 is present in the second gas as it is produced from the bottom reaction zone Col. 2, Lines 55-65)
Regarding Claim 4, the inlet gas may be preheated to 650-950 C (Col. 6, Lines 60-65) reading on the claimed range of 500-1200 C.
Regarding Claim 5, the second reduction gas comprises CO, carbon monoxide, a compound of carbon and oxygen.
Regarding Claims 6-9, the reduction gas comprises CH4, a compound of carbon and hydrogen (Col. 7, Lines 8-12), and is considered to result in at least some carburization as taught by applicant in (Page 10 of the specification); since similar conditions are present which would result in carburization, one of ordinary skill in the art would expect a similar amount of carbon content on the sponge iron product under the expectations that products formed by similar methods have similar properties. (See MPEP 2112.01(I))
Regarding Claim 10, the inlet gas may be preheated to 650-950 C (Col. 6, Lines 60-65) overlapping with the claimed range of 700-1300 C.
Regarding Claims 11-12, the reactor comprises a shaft furnace and a cooling zone after the reduction zone cooled with cooling gas CH4 (See Col.7, Lines 7-12) (Fig 1) (ore moves down in a vertical direction)
Regarding Claim 16, Bueno teaches the first process gas in the pres-reduction zone is heated to a temperature of 650-950 C (See claim 3), overlapping with the claimed range of 500-900 C; and teaches the second zone of the furnace where the second gas is introduced has a temperature of 1000-1150 C (See Claim 5), reading on the claimed range of 900-1300 C, this is considered to have a temperature difference at the end zone of least 100 C higher than the prereduction zone. (See MPEP 2144.05(I))
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as obvious over Bueno et al. (US6395055B1) in view of Boehm et al. (US20210246521A1) as applied to claims 2-11 above, in further view of Shipley (US2752234).
Regarding Claim 13, Bueno is silent regarding the use of a fluidized bed reactor for the two zones; however, Shipley teaches a method of a continuous gaseous reduction of iron ore where a primary and secondary reactor may be used where fresh reducing gas is added to recover metallic iron (See Claim 2); therefore, one of ordinary skill in the art would have been motivated to modify the zones of Bueno to be fluidized bed reactors for the purpose of forming reduced iron in an efficient manner (Col. 1, Lines 30-45)
Response to Arguments
Applicant's arguments filed 08/07/2026 have been fully considered but they are not persuasive.
Applicant argues the prior art teaches the first reaction gas has a different composition compared to the second reduction gas as the gas moves up from the first reduction zone to the second; however applicants claimed invention is directed towards the first reduction gas having a hydrogen proportion at least 5% volume higher compared to the second reduction gas and what happens within the first and second reduction zones is not what is being claimed.
This is not persuasive; the claimed invention requires a reduction zone subdivided into a pre-reduction zone supplied with a first reduction gas and a end-reduction zone supplied with a second reduction gas; wherein the gas have different compositions and the first reduction gas has a higher hydrogen proportion of at least 5% more volume compared to the second reduction gas. The second gas is a mixture of reduction gas introduced by inlet and the gas produced during reduction in the lower zone; therefore the argument being made is that the second gas supplied to the upper reaction zone has a higher hydrogen volume content during the direct reduction of iron ore to sponge iron; the claimed invention does not limit the inlet gas compositions introduced to each chamber but rather the gas compositions supplied to each zone.
Allowable Subject Matter
Claims 17-20 are objected to as being dependent upon a rejected base claim but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: The closest prior art of record is Bueno as used above, however the prior art does not teach or suggest the claimed subject matter of claims 17-20 as required by the new claims.
Conclusion
THIS ACTION IS MADE FINAL.
Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/RICARDO D MORALES/Primary Examiner, Art Unit 1738
