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 .
Information Disclosure Statement
The information disclosure statement(s) (IDS) submitted on 2/27/2023, 5/24/2024, and 10/21/2024 is/are in compliance with the provisions of 37 CFR 1.97. Accordingly, these IDSs have been considered by the examiner, except as follows: document 4 in the 5/24/2024 IDS and document 1 in the 10/21/2024 IDS, cite Chinese Patent Office communications, however no English language translations thereof were provided. Said documents have not been considered.
Claim Objections
Claim 4 is objected to because of the following informalities: Claim 4 reads “… roasting the lithium-containing raw material is to use concentrated sulfuric acid…” but should read “… roasting the lithium-containing raw material uses concentrated sulfuric acid…”. Appropriate correction is required.
Claim Rejections-35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-15 are rejected under 35 U.S.C. 112(b)/2nd par. as indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “a first purifying the leaching solution with a pH of 7.1 to 9.5” and “a second purifying the first purified solution with pH of 9 to 11” (Claims 8 and 11, respectively, additionally repeat these phrases). The literal interpretation of purifying with a pH of X is that a solution with pH of X is added to the solution to be purified, however it is clear from the disclosed examples (see specification Page 15, Lines 2-8) that the intended meaning is that the solution is purified to a pH of X (by adding a solution or material with a pH higher than X). There should be consonance between the specification and the claims, see MPEP 2173.03.
Claims 2-15 depend from Claim 1 and fail to cure the indefiniteness issues above.
Additionally, Claim 11 recites “as the second purification step to purify the a second purifying the first purified solution with pH of 9 to 11 is performed by adjusting pH using a source of an alkali metal carbonate.”. The grammatical errors make it difficult to ascertain the scope of Claim 11 and it is therefore likewise rejected as indefinite. For the purpose of this Office Action Claim 11 is interpreted as “in the second purification step, purifying the first purified solution to a pH of 9 to 11 is performed by adjusting pH using a source of an alkali metal carbonate.”
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.
Claims 1-2, 4, 6-11, and 14-15 are rejected under 35 U.S.C. 103 as being unpatentable over NPL “Recovery of lithium carbonate by acid digestion and hydrometallurgical processing from mechanically activated lepidolite” Vieceli et al. in view of US 20180147531 A1 Park et al. Claim 1 requires “A method of preparing a lithium hydroxide comprising: roasting a lithium-containing raw material in sulfuric acid”. Vieceli et al. discloses “A lepidolite concentrate was obtained by grinding the original ore to −500μm and by froth flotation, which allowed obtaining a product containing 1.95% Li (or 4.2% of Li2O). Afterwards, this lepidolite concentrate was mechanically activated in a disk mill (N.V. Tema) during 15 min and it was digested with sulphuric acid (98%) in a preheated oven, for 15 min at a temperature of 130 °C” [Page 2, Section 2.1].
Claim 1 further requires “leaching the roasted lithium-containing raw material to obtain a solution containing lithium sulfate”. Vieceli et al. discloses “Digested samples of 2.5 g were set in closed glass flasks and the leaching tests were performed with demineralized water in a thermostatic orbital shaker (at 100 rpm).” [Page 2, Section 2.2, Paragraph 1] and “The digestion performed with an acid/concentrate mass ratio of 0.66, at 130 °C for 15 min, led to the formation of lithium sulphate that is easily soluble in water.” [Page 3 Section 3.1, Paragraph 1].
Claim 1 further requires “a first purifying the leaching solution with a pH of 7.1 to 9.5; a second purifying the first purified solution with pH of 9 to 11”. As discussed in the 112b rejection (above) this is interpreted to mean a first purifying of the leaching solution to a pH of 7.1 to 9.5 and a second purifying of the first purified solution to a pH of 9 to 11. Vieceli et al. discloses a two-step purification by adding bases to the lithium sulfate solution wherein in the first step the pH is adjusted to 9.1 and in the second step the pH is adjusted to 10.5 in Figure 12a, reproduced below:
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Claim 1 further requires “obtaining an aqueous solution of a lithium hydroxide by bipolar electrodialysis of the second purified a solution.”. Vieceli et al. acknowledges conventional methods of purifying lithium including electrodialysis to generate lithium compounds (“According to Chagnes and Swiatowska (2015), the process of lithium extraction from ores involves purification mainly by precipitation, which is carried out to remove impurities, such as Ca, Al, Mn and Fe, followed by lithium concentration using mostly evaporation and finally, crystallization, carbonation or electrodialysis to produce lithium compounds.” [Page 2, Section 2.4, Paragraph 1]), however in this study they elect to use carbonation to produce lithium carbonate and do not actually perform electrodialysis.
Park et al. is similarly directed to methods of purifying lithium from lithium containing ores. Park et al. discloses “Specifically, in an embodiment of the present invention, a method of producing lithium hydroxide includes performing bipolar electrodialysis of a lithium containing solution from which divalent ion impurities are removed, concentrating lithium in the lithium-containing solution, and at the same time, converting the lithium to lithium hydroxide” [0008].
It would have been obvious to one of ordinary skill in the art to have combined the method of Vieceli et al. with the method of Park et al. because they are both similarly directed to methods of purifying lithium from ore. Furthermore the method of Park et al. specifically calls for a lithium containing solution that has had divalent ion impurities removed and the method of Vieceli et al. generates as an intermediate a lithium containing solution that has had divalent ion impurities removed.
The motivation to have used the bipolar electrodialysis of Park et al. on the second purified solution of Vieceli et al. is given by Park et al. “Each material may be obtained with high purity and a high concentration through a manufacturing method of the material according to embodiments of the present invention . Specifically, according to an embodiment of the present invention, a method for producing lithium hydroxide may be provided by economically concentrating lithium in the lithium-containing solution” [0033-0034].
Claim 2 requires “the lithium-containing raw material comprises a lithium-containing ore.”. Vieceli et al. discloses lepidolite (see Claim 1) which is understood to be a lithium containing ore.
Claim 4 requires “the roasting the lithium-containing raw material is to use concentrated sulfuric acid with a concentration of 95% or more.”. Vieceli et al. discloses 98% sulfuric acid (see Claim 1).
Claim 6 requires “the leaching the roasted lithium-containing raw material to obtain a solution containing lithium sulfate is performed by using water or diluted sulfuric acid.”. Vieceli et al. discloses “Digested samples of 2.5 g were set in closed glass flasks and the leaching tests were performed with demineralized water” [Page 2, Section 2.2, Paragraph 1].
Claim 7 requires “the water is purified water, the dilute sulfuric acid is recycled from the step of obtaining an aqueous solution of a lithium hydroxide by bipolar electrodialysis of the second purified a solution.”. Vieceli et al. discloses demineralized water (see Claim 6) which is understood to be purified water.
Claim 8 requires “as the first purification step to purify the leaching a solution, the first purifying the leaching solution with a pH of 7.1 to 9.5 is performed by adjusting the pH using a source of non-Na-based alkali.”. Vieceli et al. discloses adjusting the pH of the first solution with Ca(OH)2 (see Claim 1).
Claim 9 requires “the source of non-Na-based alkali comprises calcium hydroxide (Ca(OH)2).”. Vieceli et al. discloses adjusting the pH of the first solution with Ca(OH)2 (see Claim 1).
Claim 10 requires “the leaching step and the first purification step are conducted in a single reactor.”. Vieceli et al. does not disclose leaching and first purification happening in the same reactor, however one of ordinary skill in the art would have been able to modify Vieceli et al. to have arrived at a single reactor design for leaching and purification. The reactor design of Vieceli et al. is given by Figure 1, reproduced below:
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One of ordinary skill in the art would have recognized that throughout the steps of leaching, cooling crystallization, and neutralization precipitation only insoluble impurities are generated and the lithium remains in solution. Therefore reactor design could be simplified and upfront capital cost could be reduced by performing each step in the same reactor. Such a benefit represents a predictable and unsurprising result.
Claim 11 requires “as the second purification step to purify the a second purifying the first purified solution with pH of 9 to 11 is performed by adjusting pH using a source of an alkali metal carbonate.”. As discussed in the 112b rejection above Claim 11 is being interpreted as “in the second purification step, purifying the first purified solution to a pH of 9 to 11 is performed by adjusting pH using a source of an alkali metal carbonate.”. Vieceli et al. discloses using Na-2CO3 to purify the first purified solution to a pH of 10.5 (see Claim 1).
Claim 14 requires “after a step of obtaining an aqueous solution of a lithium hydroxide by bipolar electrodialysis of the second purified a solution, a step of crystallizing the obtained aqueous solution of a lithium hydroxide is further included.”. Park et al. discloses “after the step of performing
bipolar electrodialysis of a lithium-containing solution from which divalent ion impurities are removed, concentrating lithium in the lithium-containing solution, and at the same time, converting the lithium to lithium hydroxide, the method may further include concentrating the solution containing the lithium hydroxide to crystallize the same; and drying the crystallized lithium hydroxide to obtain lithium hydroxide in a powder form .” [0013].
Claim 15 requires “the step of crystallizing the obtained aqueous solution of a lithium hydroxide comprises: obtaining lithium hydroxide hydrate through primary crystallization; re-dissolving the obtained lithium hydroxide hydrate; obtaining a final lithium hydroxide hydrate through secondary crystallization of the re-dissolved solution.”. Park et al. does not disclose that the obtained lithium hydroxide power is in hydrate form, however one of ordinary skill in the art would know that crystallization from water would yield the salt as a hydrate. Park et al. does not disclose a second crystallization however this step would have been obvious to one of ordinary skill in the art because doing repeated crystallizations is a known general procedure for increasing the purity of solids and Park et al. is directed to obtaining high purity lithium hydroxide. The results from the second crystallization (more pure LiOH crystals) would have been predictable and unsurprising.
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over NPL “Recovery of lithium carbonate by acid digestion and hydrometallurgical processing from mechanically activated lepidolite” Vieceli et al. in view of US 20180147531 A1 Park et al., in further view of NPL “Processing of a Zimbabwean petalite to obtain lithium carbonate” Sitando et al. Regarding Claim 3, Vieceli et al. in view of Park et al. teach all of the limitations of Claim 1. Claim 3 further requires “the method further comprises calcinating the lithium-containing raw material at 950 to 1100 °C before roasting.”. Vieceli et al. does not disclose calcinating the lepidolite prior to roasting but does acknowledge that calcination is known in the art for other lithium containing ores, such as petalite (see Table 4) performed by Sitando et al. Sitando et al. discloses “The finely powdered petalite concentrate was first heated in a laboratory furnace at 1100 °C for 2 h with exact temperature regulation. Heating petalite to high temperatures results in an irreversible phase change to a β-spodumene-SiO2 solid solution which is more reactive to acid and base attack (Wietelmann and Bauer, 2003; Kamiensiki et al., 2005; Garrett, 2004). A weighed amount of ground pre-heated petalite sample was mixed with concentrated H2SO4 in a porcelain crucible.” [Page 46, Section 2.3.3].
It would have been obvious to one of ordinary skill in the art to have combined the method of Vieceli et al. and Park et al. with the method of Sitando et al. because they are all similarly directed to methods of purifying lithium from ore. The motivation to have used the pre-heating of Sitando et al. on the method of Vieceli et al. and Park et al. is given by Sitando et al. when they teach that pre-heating increases reactivity to sulfuric acid (see above).
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over NPL “Recovery of lithium carbonate by acid digestion and hydrometallurgical processing from mechanically activated lepidolite” Vieceli et al. in view of US 20180147531 A1 Park et al., in further view of US 20190136392 A1 Bourassa et al. Regarding Claim 12, Vieceli et al. in view of Park et al. teach all of the limitations of Claim 1. Claim 12 further requires “an additional purification step using an ion-exchange resin is included to remove trace impurities remaining after the second purification step.”. Neither Vieceli et al. nor Park et al. disclose an ion exchange resin.
Bourassa et al. is similarly directed to methods of purifying lithium from a lithium containing ore. Bourassa et al. discloses “partially precipitating the at least one metal ion under the form of at least one hydroxide so as to obtain … an aqueous composition comprising Li+ and having a reduced content of the at least one metal ion, …; contacting the aqueous composition comprising Li and having a reduced content of the at least one metal ion with an ion exchange resin so as to at least partially remove at least one metal ion from the composition, …; and submitting the aqueous composition comprising the lithium compound to an electrodialysis under conditions suitable for converting at least a portion of the lithium compound into lithium hydroxide.” [0024-0026].
It would have been obvious to one of ordinary skill in the art to have combined the method of Vieceli et al. and Park et al. with the method of Bourassa et al. because they are all similarly directed to methods of purifying lithium from ore. The motivation to have combined the ion exchange purification step of Bourassa et al. within the overall purification suggested by Vieceli et al. in view of Park et al. is to further reduce impurities. In particular Vieceli et al. discloses that after the second purification step there is an excess of Ca2+ ions in solution and Bourassa discloses removing Ca2+ ions via ion exchange (“For example, contacting with the ion exchange resin can allow for reducing a content of Ca2+ of the composition below about 10 mg/L, about 5 mg/L, about 1 mg/L or about 0 . 5 mg/L .” [0196]).
Claim Objections/Potentially Allowable Subject Matter
Claim 5 is objected to as being dependent upon a rejected base claim, but could potentially be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The closest prior art to Claim 5 is given by NPL “Recovery of lithium carbonate by acid digestion and hydrometallurgical processing from mechanically activated lepidolite” Vieceli et al. in view of US 20180147531 A1 Park et al., in further view of NPL “Processing of a Zimbabwean petalite to obtain lithium carbonate” Sitando et al. Claim 5 requires “in the roasting the lithium-containing raw material in sulfuric acid, a sulfuric acid equivalent is at a weight ratio of 200 to 300% to lithium weight, roasting temperature is 180 to 300 °C, and roasting time is 40 to 120 minutes.”.
Regarding the limitation of the weight ratio of sulfuric acid and lithium Vieceli et al. discloses “The effect of the acid amount was evaluated varying the acid/concentrated mass ratio between 0.66 and 1.10 (Fig. 3). For ratios from 0.66 to 0.88, no increase in the lithium extraction was found. Nevertheless, when this ratio was increased to 0.96 or higher, a rise in the lithium extraction of about 12% was verified. Thus, taking into account that sulphuric acid represents one of the main costs of the employed process, the acid amount choice should consider the resulting costs and revenues. However, mass ratios above 0.96 are not necessary since they do not reflect a considerable increase in the lithium extraction.” [Page 3, Section 3.1, Paragraph 2]. Because the concentrated mass is 1.95% lithium by weight (“A lepidolite concentrate was obtained by grinding the original ore to−500μm and by froth flotation, which allowed obtaining a product containing 1.95% Li (or 4.2% of Li2O).” [Page 2, Section 2.1, Paragraph 1]) the ratio of 0.66-1.1 g sulfuric acid/g concentrate is equivalent to 33.8-56.4 g sulfuric acid/g lithium which is well outside of the range of 2-3 g sulfuric acid/g lithium claimed. Furthermore Vieceli et al. teaches away from further lowering the sulfuric acid to lithium concentration when they teach a ratio of 0.96 g sulfuric acid/g concentrate (equivalent to 49.2 g sulfuric acid/g lithium) creates a 12% increase in recovered lithium.
Regarding the other limitations of Claim 5, namely roasting temperature is 180 to 300 °C, and roasting time is 40 to 120 minutes this is known in the art for at least some lithium containing ores. For example Sitando et al. discloses “A number of experiments were run by varying the roasting temperature in the range of 200–300 °C. The results of this investigation are presented in Fig. 3. An increase in temperature from 200 to 300 °C brings about an increase in dissolution of lithium, which is attributed to the fact that raising the temperature will increase the reaction rate. From the graph maximum extraction was achieved at 300 °C in 60 min.” [Page 47, Section 3.4.1].
Claim 13 is objected to as being dependent upon a rejected base claim, but could potentially be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. The closest prior art to Claim 13 is given by NPL “Recovery of lithium carbonate by acid digestion and hydrometallurgical processing from mechanically activated lepidolite” Vieceli et al. in view of US 20180147531 A1 Park et al. Claim 13 requires “in the step of obtaining an aqueous solution of a lithium hydroxide by bipolar electrodialysis of the second purified a solution, it is further comprised a step of supplying a generated diluted sulfuric acid to the leaching step reactor.”. The method of Vieceli et al. uses water instead of diluted sulfuric acid. One of ordinary skill in the art would know that by utilizing the waste stream of diluted sulfuric acid generated by the electrodialysis of the method of Park et al. in the leaching step of Vieceli et al. further Ca(OH)2 would have been required to neutralize the solution and precipitate impurities. In other words, the expected technical effect of modifying the disclosure of Vieceli et al. and Park et al. to have included the subject matter of Claim 13 would have been an increased input cost of material in further steps.
As potentially allowable subject matter has been indicated, applicant's reply must either comply with all formal requirements or specifically traverse each requirement not complied with. See 37 CFR 1.111(b) and MPEP § 707.07(a).
Conclusion
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/JOSHUA MAXWELL SPEER/
Examiner
Art Unit 1736
/DANIEL BERNS/Primary Examiner, Art Unit 1736
Prosecution Insights