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 12/19/2025 has been entered. Claims 1-3 and 7-23 are pending in this application and examined herein. Claims 15-16, 20-21 are withdrawn. Claim 1 is amended. Claims 3-6 are cancelled.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 12/19/2025 has been entered.
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).
Regarding claim 1, Koble teaches a method for the recovery of vanadium from ores (i.e., a feed stream containing vanadium) (Title, Col. 1 lines 8-12). Koble teaches mixing the ores with mill solution in a ball mill 13 (Col. 2 lines 56-59) comprising sodium carbonate and sodium bicarbonate (i.e., subjecting the feed stream to a leach step, the leach step comprising contacting the feed stream with an alkaline carbonate leach solution) (Col. 1 line 70 – Col. 2 line 2), where the leach step is conducted at atmospheric pressure . Koble teaches the leach step forms a leach slurry 15/18 (Col. 2 lines 60-63), comprising pregnant leach solution containing vanadium and a solid residue where the leach slurry is passed to a solid/liquid separation step to produce a pregnant leach solution 30 containing vanadium (Col. 3 lines 7-13). Koble teaches recovering a vanadium product 71 from the pregnant leach solution 30 (Col. 4 lines 33-44, Figure).
Koble does not teach wherein the feed stream containing vanadium is an alkaline feed stream.
Goddard teaches a method for the recovery of vanadium from vanadium-bearing residues (i.e., a vanadium containing feed stream) (Title, abstract). Goddard teaches subjecting the vanadium feed stream to a leach step (Col. 2 lines 50-55), the leach step comprising contacting the vanadium feed stream with an alkaline carbonate leach solution (Col. 2 lines 51). Therefore, Goddard and Koble are analogous to the instant application as both are directed to methods of recovering vanadium by leaching with alkaline carbonate leach solution. Goddard teaches recovering vanadium from high-acid-consuming residues (Col. 1 lines 7-14), where many power plant residues, for example, boiler ash and scrubber sludges, have been treated with bases, such as lime (CaO) to prevent corrosion and to scrub acidic components released during combustion (Col. 1 lines 32-36).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have recovered vanadium from high-acid consuming residues such as power plant residues as taught by Goddard in the process of Koble, as doing so would recover vanadium from waste materials, where it would have been obvious to one of ordinary skill that it would be desirable to valorize waste materials and reduce the amount of waste material that must be disposed of. Doing so would have been further obvious as both of Koble and Goddard leach vanadium with alkali carbonates, and the residues of Goddard would have a reasonable expectation of success.
Koble in view of Goddard is silent to wherein the leach step generates NaOH. However, paragraph [0068] of the present specification discloses Na2CO3/NaHCO3 in leach liquor will react with CaO/Ca(OH)2 to produce solid NaOH, in accord with the method as presently claimed. As Koble in view of Goddard discloses substantially the same process that Applicant states produces this feature (i.e., Na2CO3 and NaHCO3 in leach liquor with CaO/Ca(OH)2), one of ordinary skill would have a reasonable assumption that these features of claim 1 would also occur when practicing the method of Koble in view of Goddard. See MPEP 2112 § (III-V) and 2112.01 § (I).
Koble does not teach wherein a carbon dioxide stream is injected into the leach step to maintain a pH between 9 and 11 wherein the sparged carbon dioxide reacts with NaOH to from Na2CO3/NaHCO3.
Lakshmanan teaches a process for treatment of flyash to recover vanadium by leaching under alkaline conditions (Title, Abstract), thus Lakshmanan and Koble in view of Goddard are analogous as both are directed to recovery of vanadium metals from waste materials comprising leaching under alkaline conditions. Lakshmanan teaches after leaching, performing solid-liquid separation of the leach slurry (Col. 2 lines 39-41), and adjusting a pH of the liquid to a pH of 8.3 to 10 by carbon dioxide addition (i.e., wherein a carbon dioxide stream is sparged) (Col. 3 lines 58-65), wherein the pH may be 9.5 (Col. 5 line 12), 10.8 (Table I), 9.11, 9.24, or 9.34 (Table II), which are within the claimed pH range.
Because Koble is silent with respect to a suitable pH during the leach step, in order to carry out the invention of Koble one of ordinary skill in the art would necessarily look to the art for a reference teaching a pH suitable for the alkali leaching step of Koble, such as a pH of 9.11, 9.24, 9.34, 9.5, or 10.8, as taught by Lakshmanan. As Koble and Lakshmanan both relate to alkali leaching of vanadium from waste materials, one of ordinary skill would be motivated to use the pH range of Lakshmanan.
Koble in view of Lakshmanan does not teach the claimed order of sparging carbon dioxide into the slurry before solid liquid separation of the leach slurry. However, 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.
Koble in view of Goddard and Lakshmanan is silent to wherein the sparged carbon dioxide reacts with the NaOH generated from the leach step to form Na2CO3/NaHCO3. However, paragraphs [0069-0070] of the present specification disclose a carbon dioxide stream reacts with sodium hydroxide and other species to from Na2CO3 and NaHCO3 without any specific conditions or reagents, in accord with the method as presently claimed. As Koble in view of Goddard and Lakshmanan discloses substantially the same process that Applicant states produces this feature (i.e., contacting CO2 with a stream comprising NaOH produced from a leach step as noted regarding Goddard above), one of ordinary skill would have a reasonable assumption that these features of claim 1 would also occur when practicing the method of Koble in view of Goddard and Lakshmanan. See MPEP 2112 § (III-V) and 2112.01 § (I).
Regarding claim 2, Koble teaches the alkaline carbonate leach solution comprises one or more of sodium carbonate and sodium bicarbonate (Col. 1 line 70 – Col. 2 line 2, Figure).
Regarding claim 3, Koble teaches wherein the leach step includes contacting with oxygen in Pachuca tanks 22 (i.e., is conducted under oxidative conditions) (Col. 2 line 63 – Col. 3 line 6, Figure).
Regarding claim 7, Koble teaches wherein at least a portion 17 of the leach slurry 15 is subjected to a size reduction step 13 (Col. 2 lines 60-63, Figure).
Regarding claim 8, Koble teaches wherein the size reduction step 13 is conducted in the presence of the mill solution 14 (i.e., during the leach step) (Col. 2 lines 56-59, Figure).
Regarding claim 9, Koble teaches wherein at least a portion 17 of the leach slurry 15 is transferred to a size reduction step 13 to produce a process stream 18 with a reduced particle size (Col. 2 lines 60-64, Figure).
Regarding claim 10, Koble teaches wherein the process stream 18 is returned to ball mill 13 (part of the leach step) via overflow stream 20 (Col. 2 lines 64-65, Figure).
Regarding claim 11, Koble teaches wherein the process stream 18 is subjected to a secondary leach step 23 in the form of reground slurry 22 (Col 2 lines 63-64, 66-69, Figure)
Regarding claim 12, Koble teaches wherein the leach slurry 17 is subjected to a size reduction step 13 (Col. 2 lines 60-64, Figure), and the size reduction step is followed by a further leach step 23 (Col 2 lines 63-64, 66-69, Figure).
Regarding claim 13, Koble teaches the leach step 23 still comprises the mill solution (analogous to alkaline carbonate leach solution) (Col. 3 line 6), thus Koble teaches contacting the slurry with an alkaline carbonate leach solution.
Regarding claim 14, Koble does not teach wherein a solid stream recovered in the solid liquid separation step is subjected to a leach step to further extract vanadium.
Goddard teaches the leaching may be conducted as a two-stage countercurrent process, where the products of the first leach are filtered (i.e., solid-liquid separated), and then a solid stream recovered in the solid liquid separation step is subjected to a leach step to further extract vanadium (Col. 4 lines 20-26). Goddard teaches the two stage leach improves the use of the sodium salts (Col. 4 lines 21-22).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed leaching in two stages to subject solids recovered from the solid liquid separation step to further leaching as taught by Goddard in the leaching step of Koble, as doing so would recover additional vanadium from the vanadium containing feed stream, and improve the use of sodium salts in the leaching solution as taught by Goddard.
Regarding claim 17, Koble teaches recovering vanadium by precipitation, and does not teach wherein the step of recovering a vanadium product from the pregnant leach solution comprises contacting the pregnant leach solution with an organic solution comprising a vanadium extractant and subsequently separating a loaded organic solution containing vanadium from a barren leach solution.
Goddard teaches wherein the step of recovering a vanadium product from the liquor (i.e., pregnant leach solution) comprises contacting the pregnant leach solution with a water insoluble amine dissolved in hydrocarbon solvent (i.e., an organic solution comprising a vanadium extractant) and subsequently separating a loaded organic solution containing vanadium from a barren leach solution (Col. 4 lines 31-36). Goddard teaches the vanadium can then be stripped from organic phase with ammonia, and crystallized to form ammonium metavanadate which can be converted into a variety of useful oxide products by calcining (Col. 4 lines 36-42).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have recovered vanadium from pregnant leach solution with a vanadium extractant in organic solution as taught by Goddard in the vanadium product recovery step of Koble as doing so would produce a product that can be converted into a variety of useful products.
Regarding claim 18, Goddard teaches wherein vanadium is recovered from the loaded organic solution with a strip solution (Col. 4 lines 36-37).
Regarding claim 19, Goddard teaches wherein the method further comprises the step of recovering ammonium metavanadate (i.e., vanadium products) from the strip solution (Col. 4 lines 37-42).
Regarding claim 22, Koble teaches wherein at least a portion of barren leach solution 72 is recycled to the leach step 13 via filters 27-29 (Col. 3 lines 7-9, Figure) and streams 31 and 35 (Col. 3 lines 13-15, 18-22).
Regarding claim 23, Koble teaches wherein the barren leach solution 72 is carbonated 62 prior to being recycled to the leach step 13 (Col. 4 lines 42-44).
Response to Arguments
Applicant's arguments filed 12/19/2025 have been fully considered with the following effect:
Regarding Applicant’s argument that the Office has failed to provide evidence to support the allegation that it would have been obvious to a person of skill in the art to recover vanadium from the high-acid consuming residues of Goddard with the process of Koble (see pg. 7 of remarks), the Examiner respectfully disagrees.
As Applicant notes, the Office argues that it would have been obvious to modify he method for recovery of vanadium according Koble to use an alkaline feed stream as suggested by Goddard, as it would be desirable to a person of skill in the art to valorize and reduce waste materials. It has long been held that a rationale may be in a reference, or reasoned from common knowledge in the art, scientific principles, art-recognized equivalents, or legal precedent and that the expectation of some advantage is the strongest rationale for combining references. See MPEP 2144 (I) and (II). Therefore, as Koble is modified by Goddard to address a deficiency relative to the instant claims (Koble does not teach the use of an alkaline feed stream), and the combination of Koble and Goddard is based on the expectation of an advantage (as one of ordinary skill would find the utilization of wastes to recover an element advantageous, as they would recognize the elimination of waste and generation of vanadium to be beneficial), the Office has provided evidence to support that it would have been obvious for a person of ordinary skill to recover vanadium from the high-acid consuming residues of Goddard with the process of Koble.
Regarding Applicant’s argument that sparging of carbon dioxide into the leach slurry regenerates sodium carbonate/sodium bicarbonate in the leaching step (see pg. 7-8 of remarks), it is noted that the features upon which applicant relies (i.e., that sparging of carbon dioxide into the leach slurry occurs during the leaching step) are not recited in the rejected claims. 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). Therefore, Koble’s disclosure of oxidizing air in the leaching tank is not prohibited by the instant claims.
In response to applicant's argument that Koble in view of Goddard, Oriji, and Fu does not teach wherein the leach step is conducted at atmospheric pressure as required by claim 1 as amended (see pg. 8 of remarks). Therefore, the rejection of claims 1-3, 7-14, 17-19, and 22-23 over Koble in view of Goddard, Oriji, and Fu are withdrawn. The Examiner notes that these claims are now rejected under a new ground of rejection as necessitated by amendment, and applicant’s arguments are now moot with regard to Oriji and Fu as applied in the previous office action.
Regarding Applicant’s argument that the cited references do not disclose an increase in pH caused by formation of sodium hydroxide (see pg. 9 of remarks), it is noted that the features upon which applicant relies (i.e., that sodium hydroxide produced during leaching results in an increase in pH) are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning (see pg. 9 of remarks), it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971).
Regarding Applicant’s argument that the instant claims recite that the leach step generates sodium hydroxide, that sparged carbon dioxide reacts with the generated sodium hydroxide to regenerate alkaline carbonates, that the alkaline feed stream contains at least CaO or Ca(OH)2, and therefore are limitations of the claims as amended (see pg. 10-11 of remarks), the Examiner agrees. These limitations are taught by Koble in view of Goddard and Lakshmanan as noted above.
Regarding Applicant’s argument that there would be no reasonable expectation of success in achieving the same results as disclosed in the instant application, as alkaline materials such as calcium oxide and calcium hydroxide react with sodium carbonate/sodium bicarbonate and require a large quantity of sodium carbonate that renders the process uneconomical (see pg. 11 of remarks), the Examiner respectfully disagrees.
Goddard, which is relied upon to suggest modifying Koble to use an alkali feed stream comprising CaO, directly teaches leaching the alkaline materials with bases including sodium carbonate (Goddard: Abstract, Col. 2 lines 50-67, claims 1-2, 6-7). It has long been held that a reasonable expectation of success can be implicitly shown via the prior art teachings or as part of the obviousness analysis. See MPEP 2143.02. Therefore, even if as Applicant alleges using sodium carbonate/sodium bicarbonate to leach alkaline materials is uncommon, one of ordinary skill in the art would have a reasonable expectation of success, at least for the reason that such is directly taught within Goddard (i.e., is directly taught as functional within a single prior art reference).
Regarding Applicant’s argument that the cited references do not disclose a high level of selective vanadium extraction using the claimed invention (see pg. 11 of remarks), it is noted that the features upon which applicant relies (i.e., that a certain selectivity or level of vanadium extraction is achieved) are not recited in the rejected claims. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims.
Conclusion
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.
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, Keith Hendricks can be reached at (571)-272-1401. 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.
/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733