Prosecution Insights
Last updated: April 19, 2026
Application No. 18/551,436

METHOD FOR PRODUCING PIG IRON

Non-Final OA §103§112
Filed
Sep 20, 2023
Examiner
SMITH, CATHERINE P
Art Unit
1735
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd. )
OA Round
1 (Non-Final)
16%
Grant Probability
At Risk
1-2
OA Rounds
4y 6m
To Grant
29%
With Interview

Examiner Intelligence

Grants only 16% of cases
16%
Career Allow Rate
26 granted / 165 resolved
-49.2% vs TC avg
Moderate +14% lift
Without
With
+13.5%
Interview Lift
resolved cases with interview
Typical timeline
4y 6m
Avg Prosecution
58 currently pending
Career history
223
Total Applications
across all art units

Statute-Specific Performance

§101
0.1%
-39.9% vs TC avg
§103
61.9%
+21.9% vs TC avg
§102
10.4%
-29.6% vs TC avg
§112
25.7%
-14.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 165 resolved cases

Office Action

§103 §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 Applicant’s claim to foreign priority in application no. JP2021-061042, filed March 31, 2021, is acknowledged. Claim Objections Claim 3 is objected to because of the following informalities: please change “α = 0.017 x (0.001 x P + 0.97) … 1” to “α = 0.017 x (0.001 x P + 0.97) (1)”. Appropriate correction is required. 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. Claim 1, and dependent Claims 2-6, 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. Regarding Claim 1, the predetermined value for α is not defined, and it is unclear what values read on one which is equal to or larger than α because the value of α is currently indefinite. Examiner interprets wherein the predetermined value α is 0.017 as defined by para. [0047] of the instant specification and Claim 2. Regarding Claim 6, the usage of the phrase “at least” causes the claim to be unclear whether the claim requires input data for at least one of the conditions, or input data for all of the conditions listed, wherein the conditions listed are “a temperature and a volume of the hot air, a solution loss reaction amount, a furnace wall heat removal amount, a remaining pig iron amount, a temperature of molten iron, and the ratio R”. Claim Rejections - 35 USC § 103 In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claims 1-3 and 5 are rejected under 35 U.S.C. 103 as being unpatentable over Inada (cited by Applicant in IDS filed August 9, 2024, JP 07-305103 A, English Machine translation provided) in view of Kogure (cited by Applicant in IDS filed August 9, 2024, JP 2020152989 A English Translation provided). Regarding Claim 1 and Claim 2, Inada discloses a method for producing pig iron using a blast furnace comprising a tuyere (Abstract; Fig. 1), the method comprising: stacking a first layer comprising an iron ore material and a second layer comprising coke alternatively in the blast furnace (Fig. 1, one charging cycle; para. [0041]; para. [0034] and para.[0061], wherein charging/stacking cycle is repeated; see also para.[0027] and para. [0030]), charging the coke to a central portion of the blast furnace (Fig. 1, mixed material M which comprises coke charged to a central portion; para. [0060]-[0061]), reducing and melting the iron ore material in the first layer while injecting an auxiliary reductant into the blast furnace by hot air blown from the tuyere (para. [0042]), wherein: in the stacking, the charging of the coke is carried out once or a plurality of times during one charge of stacking a stacking unit composed of one of the first layer and one of the second layer (Fig.(b) or Fig.(d), once; Fig. 1(a) and Fig. 1(c), twice), and wherein an iron ore to coke charge ratio (O/C) is about 3.72-3.79, and wherein a coke charge rate is 405-430kg/tp, such that an iron ore charge amount is about 1507-1630kg/tp. Inada discloses and requires 0.05*(O/C)≤(OM/CM) ≤(O/C)*0.3, wherein (OM/CM) is the ore to coke ratio in the central portion, but Inada does not disclose the ratio of coke in the central portion (CM) to iron ore material charged (O), and therefore fails to disclose the claimed R value (i.e., (CM/O) ratio) of greater or equal to α (see 112b rejection and interpretation above). Kogure teaches a similar method (see Fig. 1), wherein coke is charged to a central portion in an amount defined by 36-0.104x-0.097y≤z≤108-0.313x-0.290y, wherein x is fine coal powder, y is auxiliary reducing agent, and z is the amount of coke charged to a central portion. Kogure teaches adding 150-220 kg/tp of fine coal powder in order to reduce the charged iron source successfully while preventing pressure loss from decreased coke layers, and teaches adding 10-50 kg/tp of auxiliary reducing agent in order to promote the reduction of the iron source while balancing for pressure loss and unburned char. Kogure therefore teaches adding coke to a central portion in an amount of 8.3-58.2kg/tp according to the inequality above, in order to efficiently and uniformly reduce the iron source while balancing for pressure loss (Abstract; para. [0047]; para. [0053]; [0057]-[0058]; z range calculated form x and y ranges, see also values for z in Table 4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have comprised 150-220kg/tp pulverized coal, 10-50kg/tp auxiliary reducing agent, and the amount of coke charged to a central portion defined by the inequality 36-0.104x-0.097y≤z≤108-0.313x-0.290y, and therefore an amount of 8.3-58.2 kg/tp coke charged to a central portion, as taught Kogure, for the invention disclosed by Inada. One would be motivated to include these parameter amounts in order to reduce the charged iron source successfully while preventing pressure loss from decreased coke layers (see teaching above for pulverized coal), to promote the reduction of the iron source while balancing for pressure loss and unburned char (see teaching above for auxiliary reducing agent), and to efficiently and uniformly reduce the iron source while balancing for pressure loss (see teaching above for coke charged to central portion). One of ordinary skill in the art would appreciate that central portion coke rate of 8.3-58.2 kg/tp, as taught by Kogure, and a charge iron ore rate of 1507-1630kg/tp (see Inada above), comprises a ratio CM/O, or R ratio, of 0.005-0.039, which reads on the claimed ratio R of a mass (ton/ch) of coke accumulated in the central portion to a mass (ton/ch) of iron ore material charged in the one charge (Claim 1) greater than or equal to a predetermined value α (see 112b rejection above) and further (Claim 2) greater than or equal to a predetermined value α wherein the predetermined value α is 0.017. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I. Regarding Claim 3, Inada fails to disclose the amount of iron ore pellets in the iron ore source. Kogure further teaches wherein conventionally the iron source comprises iron ore pellets in an amount of 40wt% or less, such as 15wt% (para. [0036]-[0039]; para. [0082]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used an amount of 40wt% or less, such as 15wt%, iron pellets in the iron source material, as taught by Kogure, because Kogure teaches this is a well-known and conventional amount of iron ore pellets used in blast furnace operations (see teaching above). The invention of Inada and Kogure therefore comprises a P value of 40% or less, such that α is equal to 0.017*(0.001*(0.40 or less) + 0.97) and therefore 0.0172 or less per the claimed formula. A P value of 15% for example (see teaching above), results in an α value of 0.167. Thus, the invention of Inada and Kogure, which comprises an MC/O ratio (R ratio) of 0.005-0.039 (ratio of coke charged in a central portion to total ore in one charge – see Claim 1 above), satisfies the claimed requirement wherein MC/O is equal to or greater than α. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I. Regarding Claim 5, Kogure teaches wherein the particle size or particle size distribution of the coke is not limited, and may be sized according to the porosity of voids generated therebetween the coke layers and the reactivity of the cokes (para. [0054]). Kogure further teaches wherein the central coke and the coke of the charge layer may comprise the same particle (grain) size (para. [0059]), which reads on the claim language wherein the average grain size of the coke accumulated in the central portion is equal to an average grain size of the coke comprised in the second (charge) layer. In the case where the claimed ranges “overlap or lie inside ranges disclosed by the prior art” a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). See MPEP § 2144.05.I. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Inada (cited by Applicant in IDS filed August 9, 2024, JP 07-305103 A, English Machine translation provided) in view of Kogure (cited by Applicant in IDS filed August 9, 2024, JP 2020152989 A English Translation provided), as applied to Claim 1 above, in further view of Baek (KR 20190070766 A, English Machine Translation provided). Regarding Claim 4, Inada fails to disclose wherein the strength of the coke in the central portion is greater than the strength of the coke in the second layer. Baek teaches wherein high strength coke is charged to a central portion and low strength coke is charged to the blast furnace wall portion (i.e., the claimed second layer), in order to secure liquid permeability of the blast furnace while also improving output and productivity by using low strength coke (para. [0009]; para. [0019]-[0020]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have comprised a strength of the coke accumulated in the central portion greater than a strength of the coke comprised in the second layer, as taught by Baek, for the invention disclosed by Inada and Kogure, in order to secure liquid permeability of the blast furnace while also improving output and productivity by using low strength coke (see teaching above). Claim 5 is alternatively rejected under 35 U.S.C. 103 as being unpatentable over Inada (cited by Applicant in IDS filed August 9, 2024, JP 07-305103 A, English Machine translation provided) in view of Kogure (cited by Applicant in IDS filed August 9, 2024, JP 2020152989 A English Translation provided), as applied to Claim 1 above, in further view of Nishimura (EP 1445334 A1). Regarding Claim 5, Kogure teaches wherein the particle size or particle size distribution of the coke is not limited, and may be sized according to the porosity of voids generated therebetween the coke layers and the reactivity of the cokes (para. [0054]). Kogure further teaches wherein the central coke and the coke of the charge layer may comprise the same particle (grain) size, which reads on the claim language wherein the average grain size of the coke accumulated in the central portion is equal to an average grain size of the coke comprised in the second (charge) layer, or may have different particle sizes or particle distributions (para. [0059]). Kogure fails to specifically disclose wherein the central coke comprises a larger grain size than the coke in the second (charge) layer. Nishimura teaches wherein a larger particle size of the center coke charge compared to a periphery charge (second layer of instant invention) improves the liquid permeability at the furnace bed and improves gas flow (para. [0007]; para. [0010]-[0011]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have comprised an average grain size of the coke accumulated in the central portion greater than an average grain size of the coke comprised in the second (peripheral/charge) layer, as taught by Nishimura, for the invention disclosed by Inada and Kogure, in order to improve liquid permeability of the furnace bed and to improve gas flow (see teaching above). Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over Inada (cited by Applicant in IDS filed August 9, 2024, JP 07-305103 A, English Machine translation provided) in view of Kogure (cited by Applicant in IDS filed August 9, 2024, JP 2020152989 A English Translation provided), as applied to Claim 1 above, in further view of Wakimoto (US 4857106 A) and Oya (US 6302941 B1). Regarding Claim 6, Inada and Kogure teach using thermocouples to monitor the heat conditions of the furnace and further, wherein conditions monitored and measured include temperature and volume of hot air, temperature of the coke, temperature of the molten iron, the ratio of charged ore to coke (O/C) and the ratio of ore to coke in a central portion (OM/CM), central coke rate, hydrogen gas utilization rate, pressure loss, iron ore output rate, and inner wall temperature of the furnace body and fluctuation thereof (Inada, para. [0042]; para. [0066]-[0067]; Fig. 5-7; Kogure, para. [0080]; para. [0088]-[0089]; para. [0110]; iron ore output rate reads on ‘remaining pig iron amount’). Inada and Kogure therefore disclose obtaining actual values of a data group comprising at least a temperature and a volume of the hot hair, a furnace wall heat removal amount, a remaining pig iron amount, a temperature of the molten iron, and the ore to coke ratios both in the charge (stacking layers) and the central portion, and therefore the claimed R ratio. Inada and Kogure do not disclose wherein the actual values are then used as input for training data and training an artificial intelligence model, as claimed. Wakimoto teaches a method of controlling heat conditions in a blast furnace including the claimed inputting, as training data, actual values of an input data group comprising a blast air amount, blast air pressure and tuyere nose temperature, and therefore volume and temperature of the hot air, the coke ratio, steam amount, molten metal temperature, and gas utilization ratio and solution loss carbon amount (reaction amount), for a period between a time prior to a reference time and the reference time, and of an output data group comprising temperature data of molten iron obtained in the reducing and melting at a time posterior to the reference time (Abstract; see parameters in Fig. 9), and further estimating the temperature of the molten metal by use of artificial intelligence and computing based on the input and output reference data collected at particular time intervals (Col. 17, line 39; Fig. 9, time intervals; Col. 4, lines 19-20). Oya teaches using heat conditions as input and output data in order to develop an artificial intelligence system for controlling a blast furnace, including: providing an estimation model of the heat conditions, including input conditions comprising the temperature of the molten iron and therefore heat loss of the furnace wall, tuyere temperature (temperature of hot gas), coke and pulverized coal ratios, moisture content, and output conditions include temperature of the molten iron (Fig. 6-7; Col. 3, lines 33-41; Col. 12, lines 32-36; Col. 14, lines 35-54; Abstract), inferring a level of the heat conditions in the furnace and a transition of the heat conditions in the furnace, by using the estimation model of the heat conditions in the furnace, on the basis of the obtained information of the molten iron temperature, to obtain an inferred result of the level of the heat conditions in the furnace and the transition of the heat conditions in the furnace (Claim 14); providing a correcting model of the heat conditions in the furnace by using the previous knowledge of conditions for the operation of the blast furnace (Claim 14); and automatically correcting an operational factor of the blast furnace by applying the artificial intelligence system to use the correcting model of the heat conditions in the furnace, on the basis of the inferred result, to control the temperature of the molten iron (Claim 14). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used input and output data collection methods of Wakimoto and Oya, and applied them to a predictive model by training artificial intelligence in order to estimate a future temperature of the molten iron, as taught by Wakimoto and Oya, for the invention disclosed by Inada and Kogure, in order to control heat conditions and therefore stabilize blast furnace operations (Wakimoto, Abstract; Oya, Col. 1, lines 29-35). Additionally, it would have been obvious to have collected and applied the input data and output data for the heat conditions taught by Inada, Kogure, Wakimoto and Oya, and therefore the claimed heat conditions of “at least a temperature and a volume of the hot air, a solution loss reaction amount, a furnace wall heat removal amount, a remaining pig iron amount, a temperature of molten iron, and the ratio R”, in order to expand the predictive capabilities of the artificial intelligence model, because these parameters are already monitored, and in order to be within the designated ranges required Inada and Kogure, thereby producing a stable furnace operation (see Abstract of Inada and Kogure for example; see teaching above by Oya). The method of Inada, Kogure, Wakimoto and Oya therefore reads on the claimed “inputting, as training data, actual values of an input data group comprising at least a temperature and a volume of the hot air, a solution loss reaction amount, a furnace wall heat removal amount, a remaining pig iron amount, a temperature of molten iron, and the ratio R in a predetermined period between a time prior to a reference time and the reference time, and of an output data group comprising temperature data of molten iron obtained in the reducing and melting at a time posterior to the reference time, training an artificial intelligence model to predict temperature data of the molten iron at a time posterior to the reference time from the input data group; obtaining the input data group with a current time as the reference time; and causing the trained artificial intelligence model to estimate a future temperature of the molten iron, wherein the input data group obtained in the obtaining, and actual values of the output data group corresponding to the input data group are used for input in the training”. Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Fukushima (US 4913406 A): teaches wherein smaller grain sizes of ore and coke concentrated at a central portion of the furnace causes greater pressure drops (Col. 7, lines 62-66). Ikuta (WO 2020196769 A1, English Equivalent US 20220177985 A): teaches an injection rate of pulverized iron ore from 2.5-50kg/tp in order to reduce pressure loss (Abstract; para. [0055]-[0057]). Shimizu (US 4963186 A): teaches charging coke to the central part of a blast furnace at 150 kg/charge (Col. 14, lines 30-39). Sakurai (US 6090181 A): teaches charging coke three times at a rate of 20kg/charge (Col. 7, lines 37-44). Mori (US 3588067 A): teaches a ore/coke ratio of 3.2 (which is a ratio of coke to ore of 0.3125). Any inquiry concerning this communication or earlier communications from the examiner should be directed to CATHERINE P SMITH whose telephone number is (303)297-4428. The examiner can normally be reached Monday - Friday 9:00-4:00 MT. 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 Walker can be reached at (571)-272-3458. 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. CATHERINE P. SMITH Patent Examiner Art Unit 1735 /CATHERINE P SMITH/Examiner, Art Unit 1735 /KEITH WALKER/Supervisory Patent Examiner, Art Unit 1735
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Prosecution Timeline

Sep 20, 2023
Application Filed
Dec 22, 2025
Non-Final Rejection — §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
16%
Grant Probability
29%
With Interview (+13.5%)
4y 6m
Median Time to Grant
Low
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