Prosecution Insights
Last updated: April 19, 2026
Application No. 18/494,001

METHOD FOR CHARGING RAW MATERIALS INTO BLAST FURNACE

Non-Final OA §112
Filed
Oct 25, 2023
Examiner
PULLEN, NIKOLAS TAKUYA
Art Unit
1733
Tech Center
1700 — Chemical & Materials Engineering
Assignee
JFE Steel Corporation
OA Round
1 (Non-Final)
52%
Grant Probability
Moderate
1-2
OA Rounds
3y 1m
To Grant
60%
With Interview

Examiner Intelligence

Grants 52% of resolved cases
52%
Career Allow Rate
57 granted / 110 resolved
-13.2% vs TC avg
Moderate +8% lift
Without
With
+8.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 1m
Avg Prosecution
48 currently pending
Career history
158
Total Applications
across all art units

Statute-Specific Performance

§101
0.5%
-39.5% vs TC avg
§103
45.2%
+5.2% vs TC avg
§102
12.0%
-28.0% vs TC avg
§112
35.4%
-4.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 110 resolved cases

Office Action

§112
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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(b): (b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph: The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention. Claims 1-4 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. Claim 1 recites in lines 5-8, the limitation "the method comprising discharging ore (x) charged in at least one of the plurality of main hoppers and then sequentially charging the ore from a furnace wall side toward a furnace center side by using a rotating chute". In particular the limitation as written appears to be missing at least a step between the steps of (i) discharging ore (x) charged in at least one of the plurality of main hoppers; and (ii) sequentially charging the ore (x) from a furnace wall side toward a furnace center side by using a rotating chute because (1) the manner of material flow between the main hoppers and the rotating chute is missing; and (2) the center of the furnace is not necessarily a holding location for the ore charge to be moved towards the furnace wall by the rotating chute. Claim 1 is therefore rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being incomplete for omitting essential steps, such omission amounting to a gap between the steps. See MPEP § 2172.01. Claims dependent upon claims rejected above, either directly or indirectly, are likewise rejected under this statute. Allowable Subject Matter Claims 1-4 would be allowable if rewritten or amended to overcome the rejection of claim 1 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. The following is a statement of reasons for the indication of allowable subject matter: . The closest identified prior art of record is Nakamura et al. (JP 2004010980 A, cited in IDS filed 11/01/2023, original document and machine translation supplied herein), Natsui et al. (CN 103403193 A, original document and machine translation supplied herein), and Sato et al. (JP 2016050323 A, cited in IDS filed 11/01/2023, original document and machine translation supplied herein). Regarding claim 1, Nakamura teaches a method for charging raw materials into a blast furnace (Title, pg. 3 last 3 lines). Nakamura teaches the blast furnace including a bell-less charging device (pg. 2 line 2) that includes a plurality of main hoppers 4-1 and 4-2 and an auxiliary hopper 5 (pg. 11 line 12 Fig. 1) at a furnace top portion (pg. 11 lines 9-10). Nakamura teaches the auxiliary hopper 5 having a smaller capacity than the main hoppers 4-1 and 4-2 (pg. 12 lines 5-6), the method comprising discharging ore (x) charged in at least one of the plurality of main hoppers 4-1 and 4-2 (pg. 19 lines 5-6) then sequentially charging the ore (x) from a furnace wall side toward a furnace center side by using a rotating chute 11 (Fig. 1, pg. 16 lines 1-8). Nakamura does not teach the ore (x) having a JIS reducibility index (RI) of greater than 55%, wherein discharging of low-reactivity ore (y) charged in the auxiliary hopper is started simultaneously with a start of charging of the ore (x) or at a point in time after the start of the charging, the low-reactivity ore (y) having a JIS reducibility index (RI) of 55% or less, the low-reactivity ore (y) being charged together with the ore (x) from the rotating chute, or wherein charging of the low-reactivity ore (y) is stopped at least before a point in time at which charging of 56 mass% of the ore (x) is completed based on a total amount of the ore (x) to be charged per batch. Natsui teaches a raw material charging method using a raw material charging device (i.e., a method for charging raw materials into a blast furnace) (Title). Natsui teaches the blast furnace including a bell-less charging device [0002], that includes a plurality of main hoppers 4 (Fig. 6, [0005]), the method comprising discharging ore (x) charged in at least one of the plurality of main hoppers (Fig. 6, [0040, 0052]), then sequentially charging the ore (x) from a furnace wall side toward a furnace center side by using a rotating chute 8 (Fig. 6, [0006, 0009]). Natsui does not teach an auxiliary hopper at a furnace top portion, the ore (x) having a JIS reducibility index (RI) of greater than 55%, discharging of low-reactivity ore (y) charged in the auxiliary hopper is started simultaneously with a start of charging of the ore (x) or at a point in time after the start of the charging low-reactivity ore (y) having a JIS reducibility index (RI) of 55% or less, wherein the low-reactivity ore (y) is charged together with the ore (x) from the rotating chute, or wherein charging of the low-reactivity ore (y) is stopped at least before a point in time at which charging of 56 mass% of the ore (x) is completed based on a total amount of the ore (x) to be charged per batch. Sato teaches a blast furnace operation method (Title), comprising charging raw materials into a blast furnace [0003]. Sato teaches an average reducibility index of the ore of 50% or more or 65% ore less [0013], which overlaps with an ore (x) having a JIS reducibility index (RI) of greater than 55% and a low-reactivity ore (y) having a JIS reducibility index (RI) of 55% or less. Sato does not teach the blast furnace including a bell-less charging device that includes a plurality of main hoppers and an auxiliary hopper at a furnace top portion, sequentially charging ore from a furnace wall side toward a furnace center side by using a rotating chute, wherein discharging of low-reactivity ore (y) charged in the auxiliary hopper is started simultaneously with a start of charging of the ore (x) or at a point in time after the start of the charging, wherein the low-reactivity ore (y) is charged together with the ore (x) from a rotating chute, wherein charging of the low-reactivity ore (y) is stopped at least before a point in time at which charging of 56 mass% of the ore (x) is completed based on a total amount of the ore (x) to be charged per batch. Based on the above discussion, the closest prior art, taken singularly or in combination, does not fairly suggest or render obvious a method for charging raw materials into a blast furnace as claimed. As the independent claim is free from the art, claims 2-4 are also free from the art due at least to their dependency from claim 1. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nikolas T Pullen whose telephone number is (571)272-1995. The examiner can normally be reached Monday - Thursday: 10:00 AM - 6:00 PM EST. 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 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. /Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733 /NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733
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Prosecution Timeline

Oct 25, 2023
Application Filed
Feb 28, 2026
Non-Final Rejection — §112 (current)

Precedent Cases

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

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Prosecution Projections

1-2
Expected OA Rounds
52%
Grant Probability
60%
With Interview (+8.2%)
3y 1m
Median Time to Grant
Low
PTA Risk
Based on 110 resolved cases by this examiner. Grant probability derived from career allow rate.

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