Prosecution Insights
Last updated: April 19, 2026
Application No. 17/909,042

METHOD FOR PRODUCING LITHIUM HYDROXIDE

Final Rejection §103
Filed
Sep 02, 2022
Examiner
BAUM, ZACHARY JOHN
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Dongwoo Fine-Chem Co. Ltd.
OA Round
2 (Final)
79%
Grant Probability
Favorable
3-4
OA Rounds
2y 9m
To Grant
93%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
86 granted / 109 resolved
+13.9% vs TC avg
Moderate +14% lift
Without
With
+14.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
26 currently pending
Career history
135
Total Applications
across all art units

Statute-Specific Performance

§103
41.4%
+1.4% vs TC avg
§102
21.0%
-19.0% vs TC avg
§112
28.4%
-11.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 109 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 . Response to Arguments Applicant’s arguments, see Page 4, Paragraph 7 - Page 10, Paragraph 1 of Remarks, filed November 25th, 2025, with respect to the rejections of claims 1-3 under 35 U.S.C. 102(a)(1) and claims 4-5 under 35 U.S.C. 103 have been fully considered and are persuasive. Specifically, due to amendments to claim 1 which give rise to Difference [3] cited by Applicant in Page 5, Paragraph 3 of Remarks, the rejection has been withdrawn. It is additionally noted that Differences [1] and [2] cited by Applicant in Page 5, Paragraphs 1-2 of Remarks do not distinguish the claim from Zhao. The claim does not require that the lithium sulfate solution is not treated with pH-adjusting agents before reacting with calcium hydroxide, but only that the lithium sulfate solution has a pH of 6 or less when obtained from the lithium-containing waste liquid (Difference [1]). Further, the claim does not recite removing calcium sulfate (Difference [2]). Nonetheless, a new ground of rejection is made in view of the prior art in light of amendments to claim 1. Applicant’s arguments, see Page 4, lines 9-17 of Remarks, filed November 25th, 2025, with respect to claim 3 have been fully considered and are persuasive. Due to the amendment to claim 3, the rejection under 35 U.S.C. 112(d)/4th Paragraph of August 27th, 2025 has been withdrawn. 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. The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows: 1. Determining the scope and contents of the prior art. 2. Ascertaining the differences between the prior art and the claims at issue. 3. Resolving the level of ordinary skill in the pertinent art. 4. Considering objective evidence present in the application indicating obviousness or nonobviousness. 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 are rejected under 35 U.S.C. 103 as being unpatentable over ‘144 (CN 102659144 A) (the machine translation of record is referenced below) in view of ‘012 (KR 2017-0052012 A) (the attached machine translation is referenced below). Regarding claim 1, ‘144 teaches a method for producing lithium hydroxide (‘144, [0046]-[0055]), the method comprising: obtaining aqueous lithium sulfate solution from a lithium-containing waste liquid (‘144, [0046], Li2SO4 leaching solution); and obtaining lithium hydroxide by reacting the aqueous lithium sulfate solution with calcium hydroxide (‘144, [0046], Ca(OH)2), wherein the method does not include the step of adding barium hydroxide (‘144, [0046]-[0055], barium hydroxide is not added). ‘144 does not explicitly teach that the aqueous lithium sulfate solution obtained from the lithium-containing waste liquid has a pH of 6 or less. However, ‘012 teaches a lithium sulfate solution obtained from lithium-containing waste liquid having a pH of 0-4 (‘012, [0091]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected the lithium-containing waste liquid of ‘012, which has a pH of approximately 0-4 (‘012, [0091]) as a leaching solution in the method of ‘144. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, as the aqueous lithium sulfate solution of ‘012 is a lithium sulfate leaching solution, it could be selected in the method of ‘144 as a suitable aqueous lithium sulfate solution from which to prepare lithium hydroxide (‘144, [0046]) with a reasonable expectation of success. Regarding claims 2-3, modified ‘144 renders the method of claim 1 obvious, as discussed above, wherein neither a solvent (claim 2) nor glycerin (claim 3) are added in the step of obtaining the lithium hydroxide (‘144, [0046]-[0055], no solvent is added). Claims 4-5 are rejected under 35 U.S.C. 103 as being unpatentable over ‘144 (CN 102659144 A) (the machine translation of record is referenced below) in view of ‘012 (KR 2017-0052012 A) (see the attached machine translation), as applied to claim 1 above, and further in view of Kim (KR 10-0725589 B1) (the machine translation of record is referenced below). Regarding claims 4-5, modified ‘144 renders the method of claim 1, as discussed above, further comprising obtaining lithium hydroxide solution under reduced pressure to induce crystallization (‘144, [0053]), which differs from the claimed obtaining lithium hydroxide powder by precipitating the obtaining lithium hydroxide using a precipitant (claim 4), and that the precipitant is an alcohol (claim 5). However, Kim teaches precipitating lithium hydroxide using alcohol precipitants (Kim, [0051], methanol, ethanol, propanol, butanol, 2-propanol). Figure 5 of Kim illustrates that lithium hydroxide powder is obtained by Kim’s method. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have modified the method of ‘144 by incorporating an alcohol as a precipitant, as Kim teaches that organic solvents including alcohols acting as precipitants result in a high-purity lithium hydroxide monohydrate product (Kim, [0051]). A person having ordinary skill in the art would have recognized that a high-purity product as desirable and would therefore be motivated to incorporate precipitation using an alcohol. Allowable Subject Matter Claims 6-7 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: Claims 6-7 are allowable for the same reasons detailed on Page 8, line 2 - Page 9, line 6 of the Office Action dated August 27th, 2025. In addition to those already cited, the newly cited reference ‘012 (KR 2017-0052012 A) (see the attached machine translation) also fails to teach separating a manganese, nickel and/or cobalt salt prior to obtaining a lithium sulfate solution having a pH of 6 or less, as required by claim 6 together with claim 1. 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 ZACHARY J. BAUM whose telephone number is (571)270-0895. The examiner can normally be reached Monday-Friday 8:30-5:00. 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, Anthony Zimmer can be reached at 571-270-3590. 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. /ZACHARY JOHN BAUM/Examiner, Art Unit 1736 /ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Sep 02, 2022
Application Filed
Aug 25, 2025
Non-Final Rejection — §103
Nov 25, 2025
Response Filed
Jan 12, 2026
Final Rejection — §103 (current)

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Prosecution Projections

3-4
Expected OA Rounds
79%
Grant Probability
93%
With Interview (+14.0%)
2y 9m
Median Time to Grant
Moderate
PTA Risk
Based on 109 resolved cases by this examiner. Grant probability derived from career allow rate.

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