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 Amendment
The amendment filed 07/22/2026 has been entered. Claim(s) 1-3 and 7-23 is/are pending in this application, of which claims 1-3, 7-14, 17-19, and 22-23 are examined herein. Claim(s) 15-16 and 20-21 is/are withdrawn. Claim(s) 1 is/are amended. Claim(s) 4-6 is/are cancelled.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
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, 7-14, 17-19, and 22-23 are rejected under 35 U.S.C. 103 as being unpatentable over Koble (US 3210151 A, cited in Office Action dated 04/09/2025) in view of Goddard et al. (US 4640823 A, cited in IDS filed 08/05/2022), and Lakshmanan et al. (US 4966761 A, cited in Office Action dated 03/25/2026).
Claim(s) 1-3, 7-14, 17-19, and 22-23 remain(s) rejected as set forth in the Office Action dated 03/25/2026. Claim(s) 2-3, 7-14, 17-19, and 22-23 has/have not been amended since that time, and the amendments to claim(s) 1 are of an editorial nature and do not materially affect any statements made in the rejection in the prior Office Action. Therefore, the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claim(s).
Response to Arguments
Applicant's arguments filed 07/22/2026 have been fully considered but they are not persuasive.
Regarding Applicant’s argument that claim 1 specifies that the leach step is conducted at atmospheric pressure, while Lakshmanan teaches flyash is leached at over-atmospheric pressure, and thus Lakshmanan teaches away from an atmospheric leach (see pg. 8 of remarks), the Examiner respectfully disagrees.
While as Applicant notes, Lakshmanan discloses leaching at over atmospheric pressures, Lakshmanan is relied upon instead to suggest controlling the pH of the leach slurry to be 9.5, 10.8, 9.11, 9.24, or 9.34, as Koble is silent to a suitable pH of the leach slurry, and Lakshmanan and Koble in view of Goddard both teach alkali leaching of vanadium from waste materials. Lakshmanan is not relied upon to teach or suggest that any other leaching condition of the process, such as the pressure during the leaching step of Koble, be modified by Lakshmanan.
Regarding Applicant’s argument that Lakshmanan teaches pH adjustment through carbon dioxide addition that occurs after a liquid-solid separation, which is in contrast to claim 1 which specifies that the carbon dioxide stream is sparged to the leach slurry during the leaching step (see pg. 8 of remarks), the Examiner notes that the selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. See MPEP 2144.04(IV) C. Since the instant application does not disclose any new or unexpected result due to changing the order of steps compared to the prior art (i.e., of performing carbon dioxide sparging on the leach slurry rather than a pregnant leach solution resulting from solid/liquid of the slurry), it would have been obvious to select any order of the addition of carbon dioxide because carbon dioxide is added to the vanadium-comprising leach products occurs regardless of the sequence of steps performed.
Regarding Applicant’s argument that the purpose of the carbon dioxide sparge is to form sodium carbonate/sodium bicarbonate during the leach step to further leach vanadium from the undissolved solids in the leach slurry, which would not occur if carbon dioxide addition occurs after liquid-solid separation, rendering the change to the order of steps non-obvious (see pg. 8 of remarks), the Examiner respectfully disagrees.
As an initial matter, in response to applicant's argument that the references fail to show certain features of the invention, it is noted that the features upon which applicant relies (i.e., that the carbon dioxide sparge forms sodium carbonate/sodium bicarbonate during the leach step to further leach vanadium from the undissolved solids in the leach slurry) are not recited in the rejected claim(s). Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
Further, discussion in the instant specification regarding sparging of carbon dioxide is limited to adjusting pH (e.g., [00176-00188, 00196-00198], and does not disclose sparging of carbon dioxide specifically to relate to formation of a leachant. While the instant specification does disclose a carbon dioxide addition broadly to regenerate Na2CO3/NaHCO3 (instant specification: [0070]), because of the differing terminology, the instant specification does not link the behavior to sparging of carbon dioxide to the formation of Na2CO3/NaHCO3, only the broad addition of carbon dioxide, which could be achieved by other means (e.g., bubbling, venturi injectors, packed columns, etc.). Therefore, instead the instant application appears to separately describe results of addition of carbon dioxide (formation of Na2CO3/NaHCO3) and sparging of carbon dioxide (pH control), thus the instant specification cannot support a new or unexpected result as a result of modifying the order of steps presented by Koble in view of Lakshmanan regarding sparging of carbon dioxide by presenting discussion of addition of carbon dioxide which appear to be different steps for different purposes.
Regarding Applicant’s argument that Lakshmanan’s process specifies the use of an alkali metal hydroxide solution such as NaOH to perform leaching which would react with carbon dioxide during the leaching step, and therefore it would be non-obvious to modify Lakshmanan to move the carbon dioxide sparging step to during the leaching (see pg. 9 of remarks), the Examiner notes that it is the Examiner’s position that 1. Koble be taken in view of Lakshmanan to suggest adding a carbon dioxide sparging to the process of Koble to control the pH as Koble is entirely silent to pH control of the leach slurry/solution, and 2. that the claimed order of steps for leaching and sparging occurring simultaneously would have been prima facie obvious in the combination of Koble and Lakshmanan (i.e., a combination using the leaching step described by Koble). Therefore, it is not the Examiner’s position that e.g., Lakshmanan be modified to perform its carbon dioxide sparging during the leaching step of Lakshmanan as Applicant argues.
Regarding Applicant’s argument that Lakshmanan discloses optimum extraction of vanadium for pH of 8.3-10 which occurs after the leaching step, which would not comprise maintaining a pH during the leaching step and therefore would not suggest maintaining a pH within the claimed range during a leaching step (see pg. 9 of remarks), the Examiner respectfully disagrees.
While as Applicant notes, Lakshmanan discloses values for a pH after the leaching step, the sparging of carbon dioxide to adjust the pH is only separated by a solid-liquid separation step from the leaching step. As a solid-liquid separation step would not affect the pH of the slurry/solution, adjusting the pH of the pregnant leach liquor after liquid-solid separation would result in the same pH for the pregnant leach liquor as adjusting the pH of the leach slurry during or at the end of leaching (i.e., as part of the leaching step) and then performing solid-liquid separation. Therefore, Lakshmanan in addition to teaching a suitable pH for the pregnant leach solution itself, would be recognized by one of ordinary skill to suggest suitable pH values of the leach slurry, as in either case the same outcome with respect to the pH of the pregnant leach solution is attained.
Regarding Applicant’s argument that the instant invention comprises a surprising or unexpected result in that consumption of sodium carbonate by CaO or Ca(OH)2 is reduced by introducing carbon dioxide into the leach slurry since carbon dioxide reacts with sodium hydroxide and other compounds in the leach slurry (see pg. 10 of remarks), the Examiner respectfully disagrees. It has long been held however that unexpected results must pertain to differences between the claimed invention and prior art. See MPEP §716.02. As noted at item c. above, the alleged unexpected results are associated with “carbon dioxide addition”, not sparging of carbon dioxide as claimed, therefore such an unexpected advantage cannot be the basis for nonobviousness of Applicant’s application.
Conclusion
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 Nikolas T Pullen whose telephone number is (571)272-1995. The examiner can normally be reached Monday - Thursday: 10:00 AM - 6:00 PM EST.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733
