Prosecution Insights
Last updated: April 19, 2026
Application No. 18/835,986

IMPROVEMENTS IN OR RELATING TO GRAPHITE PROCESSING

Final Rejection §103
Filed
Aug 05, 2024
Examiner
NGUYEN, HAIDUNG D
Art Unit
1761
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Graphene Star Ltd.
OA Round
2 (Final)
65%
Grant Probability
Favorable
3-4
OA Rounds
3y 2m
To Grant
93%
With Interview

Examiner Intelligence

Grants 65% — above average
65%
Career Allow Rate
401 granted / 616 resolved
At TC average
Strong +28% interview lift
Without
With
+28.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
39 currently pending
Career history
655
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
46.4%
+6.4% vs TC avg
§102
27.2%
-12.8% vs TC avg
§112
19.3%
-20.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 616 resolved cases

Office Action

§103
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 This action is responsive to applicant’s amendment filed 10/29/2025. Claims 1-16, and 18-22 pending. Claims 16, 18-21 are withdrawn from consideration as being drawn to non-elected inventions. The previous rejection of claim 15 under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph is withdrawn in view of applicant’s amendment. The previous rejection of claims 1-6, 10, 11, 13, 14 and 15 under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467) is maintained view of applicant’s amendment. The previous rejection of claims 7 under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467) and Hartkopf (DE10012072A1) is maintained in view of applicant’s amendment. The previous rejection of claims 8, 9, and 12 under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467) and Nara et al (US2014/0077136) is maintained in view of applicant’s amendment. Claim Rejections - 35 USC § 103 Claims 1-6, 10, 11, 13, 14 , 15 and 22 are rejected under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467). Regarding claim 1, Goldstein discloses a method for processing graphite in a flow reactor by subjecting a mixture of graphite flakes and water to centrifugal acceleration, which method comprises the steps of: (i) providing a flow reactor comprising a vessel (Fig. 1, reactor 3) and a plurality of rotating impellers (Fig. 1, 1 and 4) for imparting rotational motion to the reaction mixture (para 0020-0021) (ii) introducing a reaction mixture comprising natural graphite and water (para 0019, 0022) into the flow reactor; (iii) operating the activator to process the reaction mixture (para 0020-21); (iv) obtaining the processed reaction mixture from the vessel (para 0022). Goldstein does not disclose the claimed flow reactor. Krasnoff discloses a flow reactor (fluid acceleration system) which may be used may to perform a mixing process and a centrifuge process. The flow reactor which comprises (a) a vessel (interior chamber) for receiving a reaction mixture comprising natural graphite and water; (b) an activator (rotational element) for imparting rotational motion to the reaction mixture; and (c) at least one input channel (inlet) for introducing the reaction mixture into the vessel, wherein the activator is rotatably mounted on a hollow tube (Fig. 2, 132) which provides the input channel. Also see the abstract, Figs 1-6, para 0031-0038). It would have been obvious to one of ordinary skill in the art before the filling date of the invention to replace the flow reactor of Goldstein with the flow reactor of Krasnoff to process for graphite of Goldstein, with a reasonable expectation of success for removing gangue material and other impurities from graphite and reducing the amount of energy consumed by the process (para 0060). Regarding claim 2, Krasnoff discloses the activator comprises one or more arms or paddles (blades, Fig. 2, 136). Regarding claim 3, Krasnoff discloses the activator imparts centrifugal motion to the reaction mixture (para 0050, 0060). Regarding claim 4, Krasnoff discloses the rotational rate of the activator is from 1000rpm to 5000rpm (para 0050). Regarding claim 5, Krasnoff discloses the flow reactor comprises at least two activators in the vessel (blades, Fig. 2, 136). Regarding claim 6, Krasnoff discloses the two activators are co-axial (Fig. 2-6). Regarding claim 10, Krasnoff discloses the vessel of the flow reactor has a circular cross-sectional shape (Fig. 1). Regarding claim 11, Krasnoff discloses the vessel has circular-shaped sides and the activator is arranged to rotate in a plane which is substantially parallel to the circular-shaped sides (Fig. 1-6). Regarding claim 13, Goldstein discloses the reaction mixture comprises natural graphite and water in a weight ratio of from 1:40 to 1:300 (para 0022). Regarding claim 14, Goldstein discloses the reaction mixture consists of natural graphite and water (para 009). Regarding claim 15, Goldstein discloses the natural graphite is mined graphite (natural graphite (para 0022). Regarding claim 22, Goldstein discloses the natural graphite is unprocessed (natural graphite (para 0009). Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467) as applied above, further in view of Hartkopf (DE10012072A1). Goldstein in view of Krasnoff discloses a method for processing graphite described above and is incorporated herein by reference. Krasnoff discloses the flow reactor comprises at least two activators in the vessel (blades, Fig. 2, 136) but does not disclose the two activators are counter-rotating activators. Hartkopf discloses mixers which are used in the production of homogeneous mixed goods, the mixer comprises at least two activators (mixing tools), wherein the activators can rotate in opposite directions to each other (para 0010). It would have been obvious to one of ordinary skill in the art before the filling date of the invention to modify the activators of Krasnoff to be counter-rotating as disclosed by Hartkopf, because of the advantages of the continuously mixing that it has no dead space during mixing and conveying and that virtually no air inclusions occur in the mixture (para 0012). Claims 8, 9, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Goldstein et al (WO2018183521) in view of Krasnoff (US2023/0304467) as applied above, further in view of Nara et al (US2014/0077136). Goldstein in view of Krasnoff discloses a method for processing graphite described above and is incorporated herein by reference. Goldstein nor Krasnoff does not disclose the flow reactor comprises a resonator to aid the formation of the one or more acoustic waves, wherein the resonator is connected to the vessel of the flow reactor by an adaptor. Nara discloses an apparatus that is suitable for using to mix a liquid and a solid, the apparatus comprises a resonator (ultrasonicator, sonoreactor) to aid the formation of the one or more acoustic waves, wherein the resonator is connected to the vessel of the flow reactor by an adaptor (Fig. 1, para 0028-0030). It would have been obvious to one of ordinary skill in the art before the filling date of the invention to modify the flow reactor of Krasnoff to include a resonator as disclosed by Nana, with a reasonable expectation that with high velocity, the ultrasonicator is causing graphite flakes to collide with each other and leach gangue material off the collided flakes. In addition, high levels of centrifugal acceleration of the activators cause graphite flakes to swirl in the reactor. Both actions result in higher levels of graphite-water friction, which, in turn, enhances effectiveness of removal of gangue material from graphite flakes. Response to Arguments Applicant's arguments filed 10/29/2025 have been fully considered but they are not persuasive. Applicant argued that it is not possible to build the flow reactor of Goldstein and that the combination of Goldstein and Krasnoff is not obvious and would not make obvious the claimed subject matter. The examiner respectfully disagrees. The rejection is based on the combination of Goldstein and Krasnoff references, wherein the flow reactor used in the method for processing graphite of Goldstein is replaced with the flow reactor disclosed by Krasnoff to remove gangue material and other impurities from graphite and reducing the amount of energy consumed by the process. The law held that one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). In addition, a prior art reference must be considered in its entirety, i.e., as a whole, including portions that would lead away from the claimed invention. W.L. Gore & Assoc., Inc. v. Garlock, Inc., 721 F.2d 1540, 220 USPQ 303 (Fed. Cir. 1983), cert. denied, 469 U.S. 851 (1984). Even if applicant notes that it is possible to build the flow reactor of Goldstein, and the flow reactor of Krasnoff not operable, the law held that “Even if a reference discloses an inoperative device, it is prior art for all that it teaches.” Beckman Instrumentsv.LKB Produkter AB, 892 F.2d 1547, 1551, 13 USPQ2d 1301, 1304 (Fed. Cir. 1989). Therefore, “a non-enabling reference may qualify as prior art for the purpose of determining obviousness under 35 U.S.C. 103.” Symbol Techs. Inc. v. Opticon Inc., 935 F.2d 1569, 1578, 19 USPQ2d 1241, 1247 (Fed. Cir. 1991). Claims 1-15 and 22 remain unpatentable for the reasons of record. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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. Any inquiry concerning this communication or earlier communications from the examiner should be directed to HAIDUNG D NGUYEN whose telephone number is (571)270-5455. The examiner can normally be reached M-Th: 10a-3p. 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, Angela Brown-Pettigrew can be reached at 571-272-2817. 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. /HAIDUNG D NGUYEN/Primary Examiner, Art Unit 1761 2/19/2026
Read full office action

Prosecution Timeline

Aug 05, 2024
Application Filed
Jul 26, 2025
Non-Final Rejection — §103
Oct 29, 2025
Response Filed
Feb 20, 2026
Final Rejection — §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
65%
Grant Probability
93%
With Interview (+28.1%)
3y 2m
Median Time to Grant
Moderate
PTA Risk
Based on 616 resolved cases by this examiner. Grant probability derived from career allow rate.

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