Prosecution Insights
Last updated: April 19, 2026
Application No. 18/280,889

METHOD FOR PRODUCING PELLETS FIRED IN A PELLETIZING KILN

Non-Final OA §103
Filed
Sep 07, 2023
Examiner
KESSLER, CHRISTOPHER S
Art Unit
1759
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Vale S A
OA Round
1 (Non-Final)
59%
Grant Probability
Moderate
1-2
OA Rounds
3y 10m
To Grant
74%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allow Rate
465 granted / 783 resolved
-5.6% vs TC avg
Moderate +15% lift
Without
With
+15.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
61 currently pending
Career history
844
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
45.2%
+5.2% vs TC avg
§102
16.2%
-23.8% vs TC avg
§112
27.4%
-12.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 783 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 . Priority Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55. Drawings The drawings were received on 7 September 2023. These drawings are accepted. 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. Claim(s) 1-8 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0032369 A1 (hereinafter “Struber”), in view of US 4181520 A (hereinafter “Reuter”). Regarding claim 1, Struber teaches a method of operating a pelletizing plant (See title). Struber teaches that the green pellets are fired to form hard fired pellets (see Abstract of BRIEF SUMMARY). Struber teaches that the method includes carrying green pellets and lumpy agglomerates to a furnace (see Fig 1 and [0057]-[0061]). The pellets thus form a “bed” as shown in Fig 1. Struber teaches that the pellets are fired in an indurating furnace (see [0049]). Struber does not teach addition of a fuel briquette to the furnace as claimed. Struber is silent with regard to any solid fuel. Reuter teaches a method of direct reduction of iron ore (see title, abstract). Reuter teaches that a pellet is fired to reduce to sponge iron (see Abstract or col 2-3). Reuter teaches that the method uses an agglomerated reducing agent, and prefers to use a briquetted solid reducing agent (see cols 2-3). Reuter teaches that these fuel briquettes will disintegrate prior to a full heating of the pellets (see SUMMARY). Reuter teaches that this allows a volatile reducing agent to be introduced to a charging end of a furnace (see col 2-3). It would have been an obvious matter to one of ordinary skill in the art a time of filing to have practiced the pelletizing of Struber, and to have added in a volatile briquetted reducing agent as taught by Reuter (cited above), because Reuter teaches that the briquetted reducing agent is introducible at a charging section without losses to the exhaust gases (cols 2-3). Regarding claim 2, Reuter teaches that the briquetted reducing agent is added to the pellets prior to the firing for direct reduction (See Figure and col 4). Regarding claim 3, Struber teaches that the ore pellets are carried by a grate car (see Figure 1 and [0050]-[0052]). Regarding claim 4, Reuter teaches that the briquetted reducing agent includes coal (See SUMMARY or col 2 or Table at top of col 5). Regarding claim 5, Struber teaches tat the fired pellets are screened (sieved) in order to classify them (see [0052]). Regarding claim 6, Reuter teaches in an example that a ash content of the briquetted fuel is 5.23% (see Table at top of col 5), falling in the range claimed and establishing a prima facie case of obviousness for the range. Regarding claim 7, Reuter teaches that the briquette disintegrate during handling such that a range of sizes are present (see col. 5). It is believed that the briquettes would have had the size in the range as claimed. Alternatively, the size of the briquettes, by itself, is insufficient to distinguish over the briquettes of the prior art, being used in the same field of endeavor of ore reduction. Alternatively, a prima facie case of obviousness exists where the claimed ranges or amounts do not overlap with the prior art but are merely close. Titanium Metals Corp. of America v. Banner, 778 F.2d 775, 783, 227 USPQ 773, 779 (Fed. Cir. 1985). In this case the sizes disclosed (-16 mm, +16 mm) are believed to be close enough that the briquettes in the process would have functioned similarly to what is now claimed. Regarding claim 8, Struber teaches that a grate furnace can be used (see [0024]). Conclusion The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US 3732062 A is representative of prior art pelletizing operations. Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER S KESSLER whose telephone number is (571)272-6510. The examiner can normally be reached 9-5:30. 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, Curt Mayes can be reached at 571-272-1234. 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. CHRISTOPHER S. KESSLER Primary Examiner Art Unit 1734 /CHRISTOPHER S KESSLER/Examiner, Art Unit 1759
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Prosecution Timeline

Sep 07, 2023
Application Filed
Dec 27, 2025
Non-Final Rejection — §103 (current)

Precedent Cases

Applications granted by this same examiner with similar technology

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SYSTEM AND METHOD FOR MANUFACTURING A PART
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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
59%
Grant Probability
74%
With Interview (+15.0%)
3y 10m
Median Time to Grant
Low
PTA Risk
Based on 783 resolved cases by this examiner. Grant probability derived from career allow rate.

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