Prosecution Insights
Last updated: April 19, 2026
Application No. 17/779,384

BLAST FURNACE OPERATION METHOD

Non-Final OA §103
Filed
May 24, 2022
Examiner
MCGUTHRY BANKS, TIMA MICHELE
Art Unit
1733
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Nippon Steel Engineering Co. Ltd.
OA Round
3 (Non-Final)
82%
Grant Probability
Favorable
3-4
OA Rounds
2y 6m
To Grant
83%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
941 granted / 1154 resolved
+16.5% vs TC avg
Minimal +2% lift
Without
With
+1.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
65 currently pending
Career history
1219
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
40.3%
+0.3% vs TC avg
§102
19.4%
-20.6% vs TC avg
§112
33.0%
-7.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1154 resolved cases

Office Action

§103
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 . Continued Examination Under 37 CFR 1.114 A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 1/20/2026 has been entered. Status of Claims Claims 1 and 10 are currently amended, Claims 2, 3, and 7 are as originally filed, and Claims 4-6, 8, 9, and 11-13 are as previously presented. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Applicant cannot rely upon the certified copy of the foreign priority application to overcome this rejection because a translation of said application has not been made of record in accordance with 37 CFR 1.55. When an English language translation of a non-English language foreign application is required, the translation must be that of the certified copy (of the foreign application as filed) submitted together with a statement that the translation of the certified copy is accurate. See MPEP §§ 215 and 216. Claims 1-13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al in “International Conference on Applied Energy” in view of Yilmaz et al in Journal of Cleaner Production. Wang et al in International Conference on Applied Energy teaches a process simulation of blast furnace operation for coke consumption as represented below in the figures: PNG media_image1.png 452 456 media_image1.png Greyscale PNG media_image2.png 354 432 media_image2.png Greyscale Pure hydrogen as an auxiliary reducing agent is simulated in the model (page 3) via a tuyere (page 2). The limitation of “carbon consumption parameter Input ΔC” is taught by the ratio of the mass per ton of pure hydrogen from Fig 3 above (“high-concentration hydrogen-containing gas not blown under”) and the mass per ton of coke injected, which is approximately represented below: Mass of hydrogen injected (kg/tHM) Mass of coke injected (kg/tHM) Input ΔC (%) 0 385 0 10 370 2.7 20 345 5.8 30 330 9.1 40 320 12.5 50 320 15.6 60 320 18.8 Wang et al teaches a carbon consumption parameter that overlaps with 7% or more. In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists because the prior art discloses the utility of the composition over the entire disclosed range. See MPEP § 2144.05. Nonpreferred and alternative embodiments constitute prior art. Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP § 2123 II. However, Wang et al does not teach the blowing temperature and gas volume as claimed in the conditions in Claim 1. Yilmaz et al teaches modeling and simulation of hydrogen injection into a blast furnace to reduce carbon dioxide emissions. A temperature range of 80-1200 °C was assumed for the injected hydrogen (page 492) and as represented below in the drawing (page 494): PNG media_image3.png 506 560 media_image3.png Greyscale The mass and volume of hydrogen injected with respect to temperature for 30 kg/tHM is approximately represented below based on hydrogen density of 0.08988 kg/m3: Mass of hydrogen injected (kg/tHM) Volume of hydrogen injected (Nm3/tHM) Condition 20 222.52 reads on higher than 900 °C and 1200 °C or lower reads on higher than 300 °C and 600 °C or lower reads on room temperature or higher and 300 °C or lower 30 333.78 reads on higher than 900 °C and 1200 °C or lower reads on higher than 300 °C and 600 °C or lower reads on room temperature or higher and 300 °C or lower 40 445.04 reads on higher than 900 °C and 1200 °C or lower 50 556.30 reads on higher than 900 °C and 1200 °C or lower 60 667.56 reads on higher than 900 °C and 1200 °C or lower It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the modeling and simulation of Yilmaz et al with the method of Wang et al, since Yilmaz et al teaches that hydrogen at higher temperatures is beneficial to maintain the required adiabatic flame temperature (AFT) (page 494) and the energy balance of the process can be evaluated (page 491) with very good results (page 492). Regarding the condition of a blowing temperature of the high-concentration hydrogen-containing gas that is higher than 600 °C and 900 °C or lower, a particular parameter must first be recognized as a result-effective variable, i.e., a variable which achieves a recognized result, before the determination of the optimum or workable ranges of said variable might be characterized as routine experimentation; therefore, a prima facie case of obviousness exists. See MPEP § 2144.05 II B. In this case, the relationship between the mass of hydrogen injected and temperature is represented in the trend in the Fig 5. Regarding Claim 2, Yilmaz et al teaches 300 °C or lower and 200-300 Nm3/t as described above. Regarding Claim 3, Yilmaz et al teaches higher than 300 °C and 600 °C or lower and 145-600 Nm3/t as described above. Regarding Claim 4-6, Yilmaz et al teaches the AFT is usually 2000-2300 °C for blast furnaces (page 492). Regarding Claim 7, Yilmaz et al teaches higher than 600 °C and 1400 °C or lower as described above. Regarding Claim 8, Yilmaz et al teaches higher than 600 °C and the high-concentration hydrogen-containing gas is 400 Nm3/t or more as described above. Regarding Claim 9, Yilmaz et al teaches higher than 600 °C and the high-concentration hydrogen-containing gas is 400 Nm3/t or more as described above and teaches the AFT is usually 2000-2300 °C for blast furnaces (page 492). Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. Wang et al teaches a process simulation of blast furnace operation for coke consumption as represented above in Figs 1 and 3. Pure hydrogen as an auxiliary reducing agent is simulated in the model (page 3) via a tuyere (page 2). The limitation of “carbon consumption parameter Input ΔC” is taught by the ratio of the mass per ton of pure hydrogen from Fig 3 above (“high-concentration hydrogen-containing gas not blown under”) and the mass per ton of coke injected, which is approximately represented below: Mass of hydrogen injected (kg/tHM) Mass of coke injected (kg/tHM) Input ΔC (%) 0 385 0 10 370 2.7 20 345 5.8 30 330 9.1 40 320 12.5 50 320 15.6 60 320 18.8 Wang et al teaches a carbon consumption parameter that overlaps with 7% or more. In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists because the prior art discloses the utility of the composition over the entire disclosed range. See MPEP § 2144.05. Nonpreferred and alternative embodiments constitute prior art. Disclosed examples and preferred embodiments do not constitute a teaching away from a broader disclosure or nonpreferred embodiments. See MPEP § 2123 II. Wang et al teaches reducing CO2 emissions (page 1), which reads on blowing the hydrogen-containing gas at a determined gas volume. Claims 11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al as applied to claim 10 above, and further in view of Yilmaz et al. Wang et al discloses the invention substantially as claimed. Wang et al teaches a plurality of gas volume-carbon consumption parameters as represented above. However, Wang et al does not teach a plurality of blowing temperatures as in Claim 11 or a gas volume-top gas temperature change correlation as in Claim 13. Yilmaz et al is applied as discussed above. Regarding Claim 11, Yilmaz et al teaches modeling and simulation of hydrogen injection into a blast furnace to reduce carbon dioxide emissions. A temperature range of 80-1200 °C was assumed for the injected hydrogen (page 492) and as represented above in the drawing on page 494. Regarding Claim 13, Yilmaz et al further teaches using FactSage methods and physical property data to describe the blast furnace, including the top gas temperature as represented below in the drawing and table: PNG media_image4.png 696 532 media_image4.png Greyscale PNG media_image5.png 350 552 media_image5.png Greyscale The values of top gas and volume of reducing agent (including hydrogen) are used in the model, and the output values include the flame temperature (page 491). Regarding Claims 11 and 13, It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the modeling and simulation process of Yilmaz et al with the method of Wang et al, since Yilmaz et al teaches that hydrogen at higher temperatures is beneficial to maintain the required adiabatic flame temperature (AFT) (page 494) and the energy balance of the process can be evaluated (page 491) with very good results (page 492). Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Wang et al as applied to claim 10 above, and further in view of Lan et al in International Journal of Hydrogen Energy. Wang et al discloses the invention substantially as claimed. However, Wang et al does not teach a gas volume-top gas temperature change amount correlation as claimed. Wang et al teaches different gas volumes of the hydrogen gas as described above but does not teach a pressure drop change as claimed. Lan et al teaches the change in the permeability after hydrogen-rich smelting in blast furnaces represented by the following equation: S =   ∫ T s T d ∆ P T -   ∆ P s d T Where S is the comprehensive permeability index, Ts is the steep temperature rise under the pressure difference, Td is the temperature at which the burden drops, ΔPT is the pressure difference at temperature T, and ΔPS is the pressure difference at temperature Ts (pages 14258-14259). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to apply the equation of Lan et al to relate the changes in pressure with the temperature of the hydrogen gas stream in Wang et al, since Lan et al teaches that low S reflects an increase in hydrogen and increase in the reduction rate of iron-bearing burden (page 14260). Response to Arguments Applicant’s arguments with respect to claims 1-13 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Bailera et al in Journal of CO2 Utilization (2/16/2021) teaches simulation results for H2 as auxiliary reducing agents for a blast furnace as represented below in the drawings (pages 12 and 13): PNG media_image6.png 200 400 media_image6.png Greyscale PNG media_image7.png 200 400 media_image7.png Greyscale Any inquiry concerning this communication or earlier communications from the examiner should be directed to Tima M. McGuthry-Banks whose telephone number is (571)272-2744. The examiner can normally be reached Monday through Friday, 7:30 am to 4:00 pm. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith D. Hendricks can be reached at (571) 272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. Tima M. McGuthry-Banks Primary Examiner Art Unit 1733 /TIMA M. MCGUTHRY-BANKS/Primary Examiner, Art Unit 1733
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Prosecution Timeline

May 24, 2022
Application Filed
Jun 30, 2025
Non-Final Rejection — §103
Sep 18, 2025
Response Filed
Oct 16, 2025
Final Rejection — §103
Dec 22, 2025
Response after Non-Final Action
Jan 20, 2026
Request for Continued Examination
Jan 26, 2026
Response after Non-Final Action
Feb 03, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
82%
Grant Probability
83%
With Interview (+1.9%)
2y 6m
Median Time to Grant
High
PTA Risk
Based on 1154 resolved cases by this examiner. Grant probability derived from career allow rate.

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