Prosecution Insights
Last updated: April 19, 2026
Application No. 18/691,381

METHOD FOR PRODUCING LITHIUM HYDROXIDE

Non-Final OA §102§103§DP
Filed
Mar 12, 2024
Examiner
PIRO, NICHOLAS ANTHONY
Art Unit
1738
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Sumitomo Metal Mining Co., Ltd.
OA Round
1 (Non-Final)
42%
Grant Probability
Moderate
1-2
OA Rounds
3y 4m
To Grant
52%
With Interview

Examiner Intelligence

Grants 42% of resolved cases
42%
Career Allow Rate
8 granted / 19 resolved
-22.9% vs TC avg
Moderate +10% lift
Without
With
+10.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
68 currently pending
Career history
87
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
43.4%
+3.4% vs TC avg
§102
15.0%
-25.0% vs TC avg
§112
23.3%
-16.7% vs TC avg
Black line = Tech Center average estimate • Based on career data from 19 resolved cases

Office Action

§102 §103 §DP
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 . 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. Preliminary Amendment Applicant’s preliminary amendment to the claims filed 12 March 2024 has been received and considered for this action. Information Disclosure Statements The Information Disclosure Statement filed on 12 March 2024 has been received and considered by the Examiner. Specification The abstract of the disclosure is objected to because the length of the abstract exceeds the recommended 150 words. Additionally, the terms “(3A)”, “(3B)”, “(3C), and “(3D)” should be removed, as should “[Selected Drawing] Fig. 1”. A corrected abstract of the disclosure is required and must be presented on a separate sheet, apart from any other text. See MPEP § 608.01(b). Claim Rejections - 35 USC § 102 The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action: A person shall be entitled to a patent unless – (a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention. Claims 1 and 5 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Yu et al. (CN 108975358 A). The provided English machine translation of Yu is relied upon in the analysis below. Regarding claim 1, Yu discloses a method for producing lithium hydroxide ([0002]) comprising steps: (1) a lithium adsorption step of bringing a first lithium containing solution into contact with a lithium selective adsorbent to adsorb lithium on the lithium selective adsorbent (add lithium adsorbent to the solution…preferably the lithium adsorbent … is a selective adsorbent; [0013] and [0020]); (2) a lithium elution step of eluting the lithium from the lithium selective adsorbent on which the lithium is adsorbed to obtain a second lithium containing solution (wash with distilled water…to obtain Li+ impurity-removed solution; [0013]); (3) an impurity removal step of removing a part of metal ions from the second lithium containing solution to obtain a third lithium containing solution; wherein the impurity removal step includes steps: (3A) a carbonating step of adding a carbonic acid source to the second lithium containing solution to obtain rough lithium carbonate (Sodium carbonate is added to the high-concentration lithium-rich solution as a precipitant to completely precipitate Li+ and then filtered to obtain lithium carbonate precipitate; [0015]); (3B) a hydrocarbonating step of blowing carbon dioxide to a slurry containing the rough lithium carbonate to obtain a lithium hydrogen carbonate solution (lithium carbonate … is made into a solid phase water slurry, and then CO2 is introduced into the solid phase water slurry to react… and the upper lithium bicarbonate solution is taken; [0017]); (3C) a decarbonation step of heating the lithium hydrogen carbonate solution to obtain purified lithium carbonate (The lithium bicarbonate solution … is placed in a stirrer and stirred at a temperature of 90-95 °C… After drying, lithium carbonate powder with a purity greater than 99.80% is obtained; [0018]); and, (3D) an acid solution dissolution step of dissolving the purified lithium carbonate in an acid solution to obtain a third lithium containing solution (the high-purity lithium carbonate … is reacted with hydrochloric acid to prepare an aqueous solution of lithium chloride; [0019]); (4) a conversion step of converting lithium salt contained in the third lithium containing solution into lithium hydroxide to obtain a lithium hydroxide containing solution in which the lithium hydroxide is dissolved (the refined lithium chloride solution is used as the anode liquid and the lithium hydroxide solution is used as the cathode liquid to electrolyze the solution in an ion membrane electrolysis cell to obtain a lithium hydroxide solution; [0019]). Regarding claim 5, Yu discloses the method of claim 1, and further discloses a crystallization step of solidifying the lithium hydroxide dissolved in the lithium hydroxide containing solution after the conversion step (the lithium hydroxide solution is concentrated … and crystallized [0019]). 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. 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 2-4 and 6 are rejected under 35 U.S.C. 103 as being unpatentable over Yu et al. (CN 108975358 A), as applied to claim 1 above, and further in view of Snydacker (US 20190256987 A1). The provided English machine translation of Yu is relied upon in the analysis below. Regarding claim 2, Yu discloses the method of claim 1, and further teaches adding alkali after the elution step (alkali is added to the Li+ concentrate; [0014]), but Yu does not teach a neutralization step after the lithium elution step and before the carbonating step in the impurity removal step. However, Snydacker also teaches producing lithium hydroxide following treatment of a lithium containing solution with a selective adsorbent (ion-exchange system for selective lithium uptake; [0478]). Snydacker additionally teaches that their selective adsorbent has high selectivity for lithium in a liquid resource relative to other ions and strong lithium uptake in liquid resources, including those with low concentrations of lithium ([0339]), and that acid is effective at eluting the lithium ions from their selective adsorbent ([0340]). Snydacker further teaches that it is appropriate to neutralize the acidic eluent before a subsequent carbonation reaction (neutralization and purification system uses NaOH to neutralize residual acid in the lithium eluate solution… The carbonation system produces Li2CO3 from the lithium sulfate solution. Li2CO3 is precipitated in a first step by addition of an aqueous solution of Na2CO3- to the lithium sulfate solution; [0475]-[0476]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include in the method of Yu a neutralization step after the lithium elution step and before the carbonating step in the impurity removal step, wherein the second lithium containing solution used in the carbonating step is a post-neutralization liquid produced by adding a neutralizer in the neutralization step, as taught by Snydacker. One of ordinary skill in the art would have been motivated to do so because they would find it desirable to use the highly selective lithium adsorbent taught by Snydacker, and because Snydacker teaches acidic eluent that should be neutralized prior to a carbonation step that is analogous to the carbonation used in the method Yu. Regarding claim 3, Yu discloses the method of claim 1, but Yu does not teach an oxidation step and a neutralization step after the lithium elution step and before the carbonating step in the impurity removal step. However, Snydacker also teaches producing lithium hydroxide following treatment of a lithium containing solution with a selective adsorbent (ion-exchange system for selective lithium uptake; [0478]). Snydacker additionally teaches that their selective adsorbent has high selectivity for lithium in a liquid resource relative to other ions and strong lithium uptake in liquid resources, including those with low concentrations of lithium ([0339]) and that acid is effective at eluting the lithium ions from the selective adsorbent ([0340]). Snydacker further teaches that it is appropriate to neutralize and purify the acidic eluent before a subsequent carbonation reaction (neutralization and purification system uses NaOH to neutralize residual acid in the lithium eluate solution… The carbonation system produces Li2CO3 from the lithium sulfate solution. Li2CO3 is precipitated in a first step by addition of an aqueous solution of Na2CO3- to the lithium sulfate solution; [0475]-[0476]). Furthermore, Snydacker teaches that the eluent can be purified by an oxidation step after the lithium-elution step where a post-oxidation liquid is produced by adding an oxidant in an oxidation step (a lithium eluate solution produced from an ion exchange system is purified to remove impurities … In one embodiment, impurities are removed through oxidation using O2, KMnO4, H2O2, Cl2, NaOCl, or other oxidizing agents; [0240]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include in the method of Yu an oxidation step and a neutralization step after the lithium elution step and before the carbonating step in the impurity removal step, wherein the second lithium containing solution used in the carbonating step is a post-neutralization liquid produced by adding a neutralizer to a post-oxidation liquid in the neutralization step, and the post-oxidation liquid is produced by adding an oxidant in the oxidation step, as taught by Snydacker. One of ordinary skill in the art would have been motivated to include these steps because the oxidation would serve to further purify the lithium-containing eluate and because the neutralization step would serve to neutralize the acid required for elution from Snydacker’s highly selective lithium adsorbent. Regarding claim 4, Yu discloses the method of claim 1, and further teaches a step of purifying the lithium-containing solution after the acid solution dissolution step and before the conversion step (the aqueous solution of lithium chloride is purified to obtain a refined lithium chloride solution; [0019]). Yu does not teach a method to achieve this purification and, in particular, does not teach an ion-exchange step after the acid dissolution step and before the conversion step. However, Snydacker teaches that an ion-exchange step can serve to remove impurities (solution is then passed through a series of columns containing ion exchange resin that binds multivalent ions; [0489]) immediately prior to conversion to lithium hydroxide by membrane electrolysis ([0490]), the same conversion process used by Yu ([0019]). Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to purify the lithium-containing solution after the acid dissolution step and before the conversion step, as taught by Yu, where the lithium containing solution used in the conversion step is obtained by bringing the lithium salt solution obtained in the acid solution dissolution step into contact with an ion- exchange resin in the ion exchange step, as taught by Snydacker. One of ordinary skill in the art would have been motivated to do so because Yu teaches it is appropriate to purify the lithium-containing solution prior to membrane electrolysis but is silent on the details, while Snydacker teaches that ion-exchange is an appropriate technique for such a purification. Regarding claim 6, Yu discloses the method of claim 1, but does not disclose a part or all of the second lithium containing solution being repeatedly used in the lithium elution step. However, Snydacker also teaches producing lithium hydroxide using a process that comprises treatment of a lithium containing solution with a selective adsorbent followed by a lithium elution step (the material can absorb lithium from the brine … Acid is added to the tank to elute lithium from the ion exchange material producing a lithium eluate solution; [0479]). Snydacker further teaches recycling water recovered from the second lithium containing as eluent in the lithium elution step (The reverse osmosis system is used to remove water from the purified lithium eluate solution. The permeate from the reverse osmosis system is water, which is fed to the acid recycling system. … The acid recycling system … produces acid solutions for elution in the ion exchange system for selective lithium uptake; [0481] and [0484]), which meets the limitation of a part of the second lithium containing solution being repeatedly used in the elution step. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to in the method of Yu repeatedly use a part of the second lithium containing solution in the lithium elution step, as taught by Snydacker. One of ordinary skill in the art would have been motivated to do so in order to minimize the use of water resources consumed by the elution process. Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1-5 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of copending Application No. 18/267,054 in view of Yu et al. (CN 108975358 A). Regarding instant claim 1, the ‘054 application recites a method for producing lithium hydroxide comprising: an impurity removal step of removing a part of metal ions from a lithium containing solution to obtain another lithium containing solution, wherein the impurity removal step includes: a hydrocarbonating step of blowing carbon dioxide to a slurry containing the rough lithium carbonate to obtain a lithium hydrogen carbonate solution a decarbonation step of heating the lithium hydrogen carbonate solution to obtain purified lithium carbonate; and, an acid solution dissolution step of dissolving the purified lithium carbonate in an acid solution to obtain a lithium containing solution (claim 1, steps 1-4). The ‘054 application also recites the limitation of a conversion step of converting lithium salt contained in a lithium containing solution into lithium hydroxide to obtain a lithium hydroxide containing solution in which the lithium hydroxide is dissolved (claim 1, step 5). The ‘054 patent does not include a method for generating the lithium carbonate slurry used in the method described by its claim 1. However, Yu teaches a method of generating lithium carbonate to be subjected to further purification and conversion to lithium hydroxide, the method comprising the steps of: a lithium adsorption step of bringing a first lithium containing solution into contact with a lithium selective adsorbent to adsorb lithium on the lithium selective adsorbent (add lithium adsorbent to the solution…preferably the lithium adsorbent … is a selective adsorbent; [0013] and [0020]); a lithium elution step of eluting the lithium from the lithium selective adsorbent on which the lithium is adsorbed to obtain a second lithium containing solution (wash with distilled water…to obtain Li+ impurity-removed solution; [0013]); and, a carbonating step of adding a carbonic acid source to the second lithium containing solution to obtain rough lithium carbonate (Sodium carbonate is added to the high-concentration lithium-rich solution as a precipitant to completely precipitate Li+ and then filtered to obtain lithium carbonate precipitate; [0015]). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to generate the lithium carbonate to be used in the method of the ‘054 application according to the method of Yu, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so because while claim 1 of the ‘054 application is silent on the source of lithium carbonate, Yu teaches that such a slurry can be prepared from crude salt lake brine ([0012]) according to steps meeting the limitations of instant claim 1. Regarding instant claims 2 and 3, claim 4 of the ‘054 patent additionally recites the steps of oxidation and neutralization (pH adjustment) required by these instant claims. Regarding instant claim 4, claims 3 and 4 of the ‘054 application recite the additional limitation of an ion-exchange step using an ion-exchange resin required by instant claim 4. Regarding instant claim 5, claim 2 of the ‘054 application recites the additional limitation of solidifying the lithium hydroxide dissolved in the lithium hydroxide containing solution after the conversion step. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Claim 6 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-8 of copending Application No. 18/267,054 in view of Yu et al. (CN 108975358 A), as applied to claim 1 above, and further in view of Snydacker (US 20190256987 A1). Regarding instant claim 6, modified claim 1 of the ‘054 application renders the method of instant claim 1 obvious, but does not contain the limitation where a part or all of the second lithium containing solution being repeatedly used in the lithium elution step. However, Snydacker also teaches producing lithium hydroxide using a process that comprises treatment of a lithium containing solution with a selective adsorbent followed by a lithium elution step (the material can absorb lithium from the brine … Acid is added to the tank to elute lithium from the ion exchange material producing a lithium eluate solution; [0479]). Snydacker further teaches recycling water recovered from the second lithium containing as eluent in the lithium elution step (The reverse osmosis system is used to remove water from the purified lithium eluate solution. The permeate from the reverse osmosis system is water, which is fed to the acid recycling system. … The acid recycling system … produces acid solutions for elution in the ion exchange system for selective lithium uptake; [0481] and [0484]), which meets the limitation of a part of the second lithium containing solution being repeatedly used in the elution step. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to repeatedly use in the method of the ‘054 application a part of the second lithium containing solution in the lithium elution step, as taught by Snydacker. One of ordinary skill in the art would have been motivated to do so in order to minimize the use of water resources consumed by the elution process. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm. 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, Sally Merkling can be reached at (571) 272-6297. 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. /NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738 /SALLY A MERKLING/SPE, Art Unit 1738
Read full office action

Prosecution Timeline

Mar 12, 2024
Application Filed
Mar 09, 2026
Non-Final Rejection — §102, §103, §DP (current)

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Study what changed to get past this examiner. Based on 3 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
42%
Grant Probability
52%
With Interview (+10.0%)
3y 4m
Median Time to Grant
Low
PTA Risk
Based on 19 resolved cases by this examiner. Grant probability derived from career allow rate.

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