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.
Claim Amendments
Applicants amendments to the claims filed 21 May 2026 have been entered and considered for this Action.
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 1-2, 5, and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Nemkov et al. (Theor. Found. Chem. Eng. 2020, 54(4), 710-718) in view of Wu et al. (NPL document 2 on the IDS filed 13 June 2023), and with respect to claim 5, as evidenced by Pedersen et al. (Front. Plant Sci., 2013, Vol. 4, Article 140, DOI: 10.3389/fpls.2013.00140).
Regarding claim 1, Nemkov teaches a method for producing lithium hydroxide (title and abstract) comprising:
an acid solution dissolution step of dissolving lithium carbonate in an acid solution to obtain a first lithium containing solution (dissolving salt … Li2CO3 in a 4 N solution of sulfuric acid; p. 710, col. 2, ¶ 2);
an impurity removal step of removing a part of metal ions from the first lithium containing solution to obtain a second lithium containing solution (to completely eliminate the negative effect of Ca and Mg impurities on the electrolysis process and the quality of the alkali produced…it is advisable to provide the ion-exchange purification of the sulfate solution in the technological scheme before feeding it to electrolysis, p. 714, col. 2, ¶ 5, and: ion-exchange purification from Ca and Mg; Fig. 7); and,
a conversion step of converting lithium salt contained in the second lithium containing solution into lithium hydroxide by electrodialysis to obtain a lithium hydroxide containing solution in which the lithium hydroxide is dissolved (the conversion of a Li2SO4 solution into a LiOH solution was carried out in an electrolyser, the anode and cathode spaces of which were separated by a cation-exchange membrane; p. 711, col. 1, ¶ 2, and membrane electrolysis, Fig. 7).
Nemkov further teaches adjusting the pH of the first lithium containing solution in a pH adjustment step (neutralization) by the addition of an alkali to the lithium-containing solution, where the alkali is lithium carbonate (neutralization of H2SO4 in the spent anolyte is carried out by its contact with solid lithium carbonate; p. 712, ¶ 4). Nemkov additionally teaches the impurity removal step comprising an ion-exchange step where the post-pH adjustment liquid is brought into contact with an ion-exchange resin (Lewatit TP-208; p. 714, col. 2, ¶ 5) to obtain a second lithium containing solution, which is then sent to an electrodialysis step (membrane electrolysis; Fig. 7).
Nemkov does not teach the hydrocarbonating or decarbonation steps recited in the instant claim, nor does Nemkov teach the lithium carbonate added in the pH adjustment step being the purified lithium carbonate obtained in the decarbonation step.
However, Wu teaches a method of purifying lithium carbonate by carbonation-decarbonation at low cost, high efficiency and low pollution (p. 594, ¶ 2). In particular, Wu teaches a method comprising:
a hydrocarbonating step of blowing carbon dioxide to a slurry of a mixture of water and rough lithium carbonate to obtain a lithium hydrogen carbonate solution (10g sample [of industrial grade lithium carbonate] was accurately weighed and immersed in 300ml deionized water in a three-necked flask with agitation to form slurry…CO2 gas was joined into the reactor by the rubber tube in agitating condition about 30 minutes. …converting into water-soluble LiHCO3; p. 596, “Carbonation Process”); and,
a decarbonation step of heating the lithium hydrogen carbonate solution to obtain a purified lithium carbonate (LiHCO3 solution obtained by the last step was evaporated … 90 °C was controlled by water bath in this process. The Li2CO3 precipitat[e] was rinsed several times and obtained by filtering; p. 596, “Decomposition process”);
Wu further teaches that this purification procedure of carbonation-decarbonation cycles decreases the impurity content of K, Na, Ca and Mg (Conclusions, ¶ 1), some of the same impurities identified by Nemkov as undesirable and potentially interfering with their method (p. 714, col. 1, ¶ 3-col. 2, ¶ 1).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to first treat the lithium carbonate used in the method of Nemkov with the carbonation-decarbonation steps taught by Wu. One of ordinary skill in the art would have been motivated to do so in order purify the lithium carbonate entering the method of Nemkov. Specifically, one would be motivated to use the low-cost method taught by Wu in order remove impurities in the feedstock that are identified by Nemkov as undesirable.
It would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the purified lithium carbonate from the decarbonation step taught by Wu in the pH adjustment step taught by Nemkov, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so in order to avoid introducing more impurities while incurring little additional cost.
Regarding claim 2, modified Nemkov teaches the method of claim 1, where Nemkov further teaches a crystallization step of solidifying the lithium hydroxide dissolved in the lithium hydroxide containing solution after the conversion step (p. 715, “Crystallization and Washing of Lithium Hydroxide Monohydrate” and Fig. 7, “Crystallization”).
Regarding claim 5, modified Nemkov teaches the method of claim 1, where the post-pH adjustment liquid after the pH adjustment step is between 7 and 8 (pH 7-8, Fig. 7 top left), which lies in the instantly claimed range.
Regarding claim 8, modified Nemkov teaches the method of claim 1, where Wu teaches in the decarbonation step the lithium hydrogen carbonate (lithium bicarbonate) is heated at 90 °C (LiHCO3 solution obtained by the last step was evaporated … 90 °C was controlled by water bath in this process; p. 596, “Decomposition Process”), which falls in the instantly claimed range.
Claims 3 and 4 are rejected under 35 U.S.C. 103 as being unpatentable over Nemkov et al. (Theor. Found. Chem. Eng. 2020, 54(4), 710-718) in view of Wu et al. (NPL document 2 on the IDS filed 13 June 2023) and Snydacker et al. (US 2019/0256987 A1).
Regarding claim 3, Nemkov teaches a method for producing lithium hydroxide (title and abstract) comprising:
an acid solution dissolution step of dissolving lithium carbonate in an acid solution to obtain a first lithium containing solution (dissolving salt … Li2CO3 in a 4 N solution of sulfuric acid; p. 710, col. 2, ¶ 2);
an impurity removal step of removing a part of metal ions from the first lithium containing solution to obtain a second lithium containing solution (to completely eliminate the negative effect of Ca and Mg impurities on the electrolysis process and the quality of the alkali produced…it is advisable to provide the ion-exchange purification of the sulfate solution in the technological scheme before feeding it to electrolysis, p. 714, col. 2, ¶ 5, and: ion-exchange purification from Ca and Mg; Fig. 7); and,
a conversion step of converting lithium salt contained in the second lithium containing solution into lithium hydroxide by electrodialysis to obtain a lithium hydroxide containing solution in which the lithium hydroxide is dissolved (the conversion of a Li2SO4 solution into a LiOH solution was carried out in an electrolyser, the anode and cathode spaces of which were separated by a cation-exchange membrane; p. 711, col. 1, ¶ 2, and membrane electrolysis, Fig. 7).
Nemkov further teaches adjusting the pH of the first lithium containing solution in a pH adjustment step (neutralization) by the addition of an alkali to the lithium-containing solution, where the alkali is lithium carbonate (neutralization of H2SO4 in the spent anolyte is carried out by its contact with solid lithium carbonate; p. 712, ¶ 4). Nemkov additionally teaches the impurity removal step comprising an ion-exchange step where the post-pH adjustment liquid is brought into contact with an ion-exchange resin (Lewatit TP-208; p. 714, col. 2, ¶ 5) to obtain a second lithium containing solution, which is then sent to an electrodialysis step (membrane electrolysis; Fig. 7).
Nemkov does not teach the hydrocarbonating or decarbonation steps, recited in the instant claim, nor does Nemkov teach the lithium carbonate added in the pH adjustment step being the purified lithium carbonate obtained in the decarbonation step. Nemkov also does not teach a step of adding an oxidant to the first lithium-containing solution to obtain a post-oxidation liquid.
However, Wu teaches a method of purifying lithium carbonate by carbonation-decarbonation at low cost, high efficiency and low pollution (p. 594, ¶ 2). In particular, Wu teaches a method comprising:
a hydrocarbonating step of blowing carbon dioxide to a slurry of a mixture of water and rough lithium carbonate to obtain a lithium hydrogen carbonate solution (10g sample [of industrial grade lithium carbonate] was accurately weighed and immersed in 300ml deionized water in a three-necked flask with agitation to form slurry…CO2 gas was joined into the reactor by the rubber tube in agitating condition about 30 minutes. …converting into water-soluble LiHCO3; p. 596, “Carbonation Process”); and,
a decarbonation step of heating the lithium hydrogen carbonate solution to obtain a purified lithium carbonate (LiHCO3 solution obtained by the last step was evaporated … 90 °C was controlled by water bath in this process. The Li2CO3 precipitat[e] was rinsed several times and obtained by filtering; p. 596, “Decomposition process”);
Wu further teaches that this purification procedure of carbonation-decarbonation cycles decreases the impurity content of K, Na, Ca and Mg (Conclusions, ¶ 1), some of the same impurities identified by Nemkov as undesirable and potentially interfering with their method (p. 714, col. 1, ¶ 3-col. 2, ¶ 1).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to first treat the lithium carbonate used in the method of Nemkov with the carbonation-decarbonation steps taught by Wu. One of ordinary skill in the art would have been motivated to do so in order purify the lithium carbonate entering the method of Nemkov. Specifically, one would be motivated to use the low-cost method taught by Wu in order remove impurities in the feedstock that are identified by Nemkov as undesirable.
It would have been further obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the purified lithium carbonate from the decarbonation step taught by Wu in the pH adjustment step taught by Nemkov, thereby arriving at the instantly claimed invention. One of ordinary skill in the art would have been motivated to do so in order to avoid introducing more impurities while incurring little additional cost.
Furthermore, Snydacker also teaches a process for the recovery of lithium from liquid resources (abstract) and further teaches that transition metals in such lithium-containing solutions (brine) can be removed by adding an oxidant (transition metals are removed from the brine using oxidative processes, including chlorine gas, ozone gas, sodium metabisulfite, sodium hypochlorite, hydrogen peroxide, air, combinations thereof, or other oxidants; [0394]).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to add an oxidant to the first lithium-containing solution to obtain a post oxidation liquid, as taught by Snydacker, and to follow this with the pH adjustment and ion-exchange steps taught by Nemkov. One of ordinary skill in the art would have been motivated to do so because such a step would facilitate the removal of any transition metal impurities in the lithium-containing solution as taught by Snydacker, which helps to achieve the same goal as Nemkov of producing lithium products of high purity (title).
Regarding claim 4, modified Nemkov teaches the methos of claim 3, and Nemkov further teaches a crystallizing step of solidifying the lithium hydroxide dissolved in the lithium containing solution after the conversion step (resulting solution was cooled in a closed flask to 60°C; crystals were formed in the solution; p. 715, col. 1, ¶ 8).
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 1-6 of copending Application No. 18/691,381 in view of Nemkov et al. (Theor. Found. Chem. Eng. 2020, 54(4), 710-718).
Regarding instant claim 1, claims 1 and 4 of the ‘381 application recite a method for producing lithium hydroxide comprising a hydrocarbonating step of blowing carbon dioxide to a slurry of a mixture of water and rough lithium carbonate to obtain a lithium hydrogen carbonate solution (claim 1, step 3B); (2) a decarbonation step of heating the lithium hydrogen carbonate solution to obtain a purified lithium carbonate (claim 1, step 3C); (3) an acid solution dissolution step of dissolving the purified lithium carbonate in an acid solution to obtain a first lithium containing solution (claim 1, step 3D); (4) an impurity removal step of removing a part of metal ions from the first lithium containing solution to obtain a second lithium containing solution, wherein this step comprises an ion-exchange step of bringing the solution into contact with ion-exchange resin to obtain a lithium containing solution (claim 4); and (5) a conversion step of converting lithium salt contained in the second lithium containing solution into lithium hydroxide (claim 1, step 4). The claims of the ‘381 application do not include the method by which lithium hydroxide is produced, nor do they include the pH adjustment step after the acid dissolution step and before the ion-exchange step or that the product of the decarbonation be used as the alkali in such a step.
However, Nemkov teaches a process for producing a lithium hydroxide containing solution by converting a lithium salt in a solution formed from lithium carbonate into lithium hydroxide by electrodialysis (membrane electrolysis; abstract and Fig. 7). Nemkov further teaches that many industries that use lithium products are in dire need of lithium hydroxide, as its monohydrate (p. 710, ¶ 2), and that the pH of the lithium containing solution should be adjusted by adding lithium carbonate before the ion exchange step (p. 712, ¶ 4 and Fig. 7-8), and that the capacity of ion-exchange resin for impurity ions increases at higher pH (p. 715, ¶ 3).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention convert the lithium containing solution obtained from the method of claims 1 and 4 of the ‘381 application using the electrodialysis steps taught by Nemkov. One of ordinary skill in the art would have been motivated to do so because while claim 1 of the ‘381 application recites a step to convert lithium in solution into lithium hydroxide it does not provide the details required to do so, while Nemkov provides these details.
It would have been further obvious to include the pH adjustment steps taught by Nemkov in the method of the ‘381 application because Nemkov teaches that such adjustment is appropriate before the ion-exchange and electrodialysis steps.
It would have been further obvious to use to purified lithium carbonate obtained from step 3B of claim 1 of the ‘381 application because it would introduce fewer impurities that other unpurified sources of lithium carbonate, thereby arriving at the invention of instant claim 1.
Regarding instant claim 2, the further limitations of this claim are recited in claim 5 of the ‘381 application and it would have been obvious to combine this crystallization step with the ion-exchange step recited in claim 4 in order to afford a solid product.
Regarding instant claim 3 and 4, modified claim 4 of the ‘381 application teaches all the limitations of instant claim 1, as analyzed above, and therefore also teaches all the limitations of instant claims 3 and 4, with the exception of the step of adding an oxidant to the first lithium containing solution obtained after the acid-dissolution step.
However, claim 3 of the ‘381 application recites an oxidation step being included in the process to produce lithium hydroxide. Though claim 3 indicates that the oxidation step occur before the carbonating step, the courts have held that any order of performing process steps is prima facie obvious in the absence of new or unexpected results (In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930); Ex parte Rubin, 128 USPQ 440 (Bd. App. 1959)). See MPEP §2144.04 IV C. Thus, the instantly claimed order of steps is an obvious variant of the steps recited in the claims of the ‘381 application.
This is a provisional non-statutory double patenting rejection.
Claim 8 is provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-6 of copending Application No. 18/691,381 in view of Nemkov et al. (Theor. Found. Chem. Eng. 2020, 54(4), 710-718), as applied to claim 1 above, and further in view of Wu et al. (NPL document 2 on the IDS filed 13 June 2023).
Regarding instant claim 8, claim 1 of the instant application is obvious over claim 4 of the ‘381 application in view of Nemkov, but claim 1 of the ‘381 application recites a decarbonation step (3C) utilizing heating, it does not specify the temperature to which the lithium hydrogen carbonate should be heated.
However, Wu teaches a similar process for carbonating and decarbonating lithium carbonate to purify it and further teaches that the decarbonation occurs at 90 °C (LiHCO3 solution obtained by the last step was evaporated … 90 °C was controlled by water bath in this process. The Li2CO3 precipitat[e] was rinsed several times and obtained by filtering; p. 596, “Decomposition process”).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to carry out step 3C of claim 1 in the ‘381 application at 90 °C, as taught by Wu.
One of ordinary skill in the art would have been motivated to do so because while claim 1 of the ‘381 application is silent on this detail, Wu teaches that this temperatures is effective for carrying out the desired transformation.
This is a provisional non-statutory double patenting rejection.
Response to Arguments
Applicant's arguments, page 7-10 of the reply filed 21 May 2026, regarding the rejections under 35 USC § 103 been fully considered but they are not persuasive.
Applicant argues that it would not have been obvious to use the purified lithium carbonate obtained from the method of Wu as the alkali in the method Nemkov, and that the effect of cost-savings realized by the inventors of the claimed invention is unexpected. Examiner respectfully disagrees with this conclusion.
As analyzed above, Wu teaches that their method provides purified lithium carbonate at low-cost (The carbonation-decomposition method [for preparing high-purity Li2CO3 with industrial grade Li2CO3] is a promising way due to its low-cost, high efficient [sic] and low pollution.; p. 594, ¶ 2). Therefore it would have been obvious to use the low-cost, purified Li2CO3 prepared by the method of Wu in the method of Nemkov, which itself calls for using lithium carbonate and is directed toward achieving high purity products. The cost-savings associated with doing so are not an unexpected advantage, as Wu teaches that their method is low-cost.
Applicant's arguments, page 10-11 of the reply, regarding the Double Patenting rejections been fully considered but they are not persuasive.
Applicant requests reconsideration of the double-patenting rejection in view of the amended claims, but these amendments do not render the instant claims non-obvious over those of co-pending application 18/691,381, as analyzed above.
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 Nicholas A Piro whose telephone number is (571)272-6344. The examiner can normally be reached Mon-Fri, 8:00 am-5:00 pm.
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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.
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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