Prosecution Insights
Last updated: July 17, 2026
Application No. 18/270,560

REDUCTION OF CHALCOPYRITE BY AN AQUEOUS PHASE REDUCANT TO ENABLE HYDROMETALLURGICAL EXTRACTION OF COPPER

Non-Final OA §102§103§112
Filed
Jun 30, 2023
Priority
Dec 30, 2020 — provisional 63/131,838 +3 more
Examiner
WILKINS III, HARRY D
Art Unit
1794
Tech Center
1700 — Chemical & Materials Engineering
Assignee
The Trustees of Columbia University in the City of New York
OA Round
1 (Non-Final)
62%
Grant Probability
Moderate
1-2
OA Rounds
0m
Est. Remaining
81%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allowance Rate
685 granted / 1097 resolved
-2.6% vs TC avg
Strong +19% interview lift
Without
With
+18.7%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
36 currently pending
Career history
1140
Total Applications
across all art units

Statute-Specific Performance

§101
1.0%
-39.0% vs TC avg
§103
75.2%
+35.2% vs TC avg
§102
5.0%
-35.0% vs TC avg
§112
6.1%
-33.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1097 resolved cases

Office Action

§102 §103 §112
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 . Election/Restrictions Applicant’s election without traverse of group I, claims 1-11, 19, and 20, in the reply filed on 2 March 2026 is acknowledged. In reviewing Applicant’s response, the Office was made aware of an error in the prior Office action. The instant application in a national stage application claiming priority to a PCT application. Thus, the Office should have applied the unity of invention standard rather than regular US restriction practice. However, under the unity of invention standard, the grouping of claims set forth in the action mailed 29 December 2025 would continue to be proper. The common features between groups I and II are not a special technical feature in that the common features do not provide a contribution over the prior art. See rejection grounds set forth below using Staker (US 3,958,983 A). 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. Claim 11 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being 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 11 recites the limitation "the electrochemical device" in the last line. There is insufficient antecedent basis for this limitation in the claim. Claim 6 recites “an electrochemical device”; however, claim 11 depends from claim 1 not claim 6. For purposes of further examination, the Office will assume claim 11 to be dependent upon claim 6 instead of claim 1 to provide proper antecedent basis for the claim limitations. Such assumption appears to be consistent with the disclosure, particularly fig. 2 and paragraph [0068], as well as claim 19. 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, 2, 9, and 10 are rejected under 35 U.S.C. 102(a)(1) as being clearly anticipated by Staker (US 3,958,983 A). Staker teaches (see abstract, cols. 1 and 2) a process for producing a copper product (e.g. copper, copper sulfide) from a copper concentrate (chalcopyrite concentrate) comprising providing the copper concentrate (chalcopyrite concentrate), contacting the composition with an aqueous solution including a chemical reducing agent (vanadium, chromium or titanium ions), reacting the copper concentrate with the chemical reducing agent to reduce copper within the copper concentrate (reaction (1) and formation of copper metal noted at col. 2, lines 2-7) and isolating (liquid-solid separation techniques) the solid phase reaction product that included a copper product. Regarding claim 2, Staker teaches the copper concentrate being chalcopyrite. Regarding claim 9, Staker teaches using vanadium (II) or chromium (II) ions as the chemical reducing agent. Regarding claim 10, in equation (1), col. 2, lines 30-31, Staker teaches the chemical reducing agent being chromium (ii) chloride. 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. Claims 3-5 are rejected under 35 U.S.C. 103 as being unpatentable over Staker (US 3,958,983 A) in view of Blanco et al (US 4,093,526 A). Regarding claims 3-5, Staker teach (see col. 2, lines 19-26) that the solid phase reaction product may be leached with copper chloride with subsequent electrowinning to isolate the copper product. Staker fails to teach the copper chloride leachant being acidic or the electrowinning step regenerating the acid. Blanco et al teach (see fig. 1, abstract, col. 7, lines 11-31) a process for the recovery of copper metal from a copper bearing material, comprising leaching the copper-bearing material with sulfuric acid followed by electrowinning of the pregnant solution which recovered pure copper metal and regenerated the sulfuric acid which is recycled to the leaching step. Therefore, it would have been obvious to one of ordinary skill in the art to have applied the sulfuric acid leaching step taught by Blanco et al in place of the copper chloride leaching step of Staker by simple substitution according to known techniques because the leaching and electrowinning steps of Blanco et al recovered copper as pure metal while also regenerating the leachant, thereby reducing waste. Claims 6-8 are rejected under 35 U.S.C. 103 as being unpatentable over Staker (US 3,958,983 A) in view of Heimala et al (US 2010/0180727 A1). Regarding claims 6 and 7, Staker discloses isolating the liquid phase reaction product (“residue and solution are separated by conventional liquid-solid separation techniques”). The oxidized chemical reducing agent, e.g. vanadium or chromium ions having an oxidation state higher than +2, e.g. +3, +4, +5, +6, was inherently present in the liquid phase reaction product since the vanadium or chromium ions were not recovered in the solid residue. Staker does not teach treatment of the liquid phase in an electrochemical reactor. Heimala et al teach (see abstract, fig. 1, paragraphs [0026], [0027], and [0036]) a process wherein a liquid phase reaction product from a leaching step of a copper bearing material with a solution containing vanadium or chromium ions is fed to an electrochemical device where the oxidized (higher oxidation state) vanadium or chromium ions were reduced (lower oxidation state) at the anode of the electrochemical device and the now reduced oxidized chemical reducing agent is returned to the leaching step. Therefore, it would have been obvious to one of ordinary skill in the art to have added an electrochemical device as taught by Heimala et al to the process of Staker for the purpose of regenerating the vanadium or chromium chemical reducing agent from its oxidized state for the purpose of reducing the amount of waste generated by the process of Staker by regenerating the low oxidation state vanadium or chromium ion chemical reducing agent. Regarding claim 8, Heimala et al teach (see fig. 1, paragraph [0033]) that a copper product was isolated from the liquid phase reaction product. Therefore, it would have been obvious to one of ordinary skill in the art to have performed the copper recovery step of Heimala et al on the liquid phase reaction product of Staker to recover additional copper that had become solubilized into the liquid phase reaction product. Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Staker (US 3,958,983 A) in view of Heimala et al (US 2010/0180727 A1) as applied to claim 6 above, and further in view of Deberry et al (US 5,705,135 A and Souentie et al (“Temperature, charging current and state of charge effects on iron-vanadium flow batteries operation”). Staker teaches (see col. 2, lines 13-18) that the iron liberated from the chalcopyrite is recovered as ferrous (iron (ii)) ions. Staker additionally teaches (see col. 1, lines 64-67) isolation (collection) of the gaseous hydrogen sulfide product and potentially converting it to elemental sulfur by means of conventional processes. Heimala et al teach (see paragraph [0036]) that within the electrochemical cell oxidation of metal ions occurs at the anode and reduction of metal ions occurs at the cathode. Heimala et al also teach that additional oxidation of the anolyte may be performed by feeding oxygen-containing gas into the anolyte and/or that additional reduction of the catholyte may be performed by performing an additional reduction. Staker and Heimala et al fail to teach the conversion of the hydrogen sulfide product to elemental sulfur being done by reaction with a stream of ferric iron and sending the resulting ferrous iron stream to the electrochemical cell. Deberry et al teach (see abstract, figs. 2 and 3) a process for converting hydrogen sulfide to elemental sulfur comprising reacting the hydrogen sulfide with a stream of ferric iron (Fe+3) which results in the formation of elemental sulfur and ferrous iron (Fe+2). The ferrous iron is then sent to an electrochemical cell (20) where the ferrous iron is oxidized at the anode to form ferric iron. Note that Deberry et al required a voltage of 5.5 V to drive the regeneration of the ferric ions. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the process for converting hydrogen sulfide to elemental sulfur taught by Deberry et al to the process of Staker because Staker teaches using conventional methods for converting hydrogen sulfide to elemental sulfur and Deberry et al teach that the process operated (see col. 2, lines 52-67) in an ecologically prudent manner with no release of sulfur, no generation of solid waste, while also using a regenerable absorbent with minimal equipment footprint. From Staker, Heimala et al and Deberry et al, there was no recognition that the electrochemical cell of Heimala et al and the electrochemical cell of Deberry et al were the same electrochemical cell as required by the recitation in claim 11 of “the electrochemical device” (emphasis added). In the field of electrochemical cells, iron-vanadium flow batteries are known. See Souentie et al at abstract, fig. 1. During charging of the flow battery, the opposite of reactions (7)-(9) (see section 3.1) occurs. These charging reactions include oxidation of ferrous (Fe+2) iron ions to ferric (Fe+3) iron ions and reduction of vanadium (III) ions to vanadium (II) ions. The overall voltage necessary to drive the reactions was 1.029 V. One of ordinary skill in the art would have recognized that (1) the reaction required by the electrochemical cell of Heimala et al in the context of the process of Staker was reduction of the vanadium (III) ions to vanadium (II) ions and (2) the reaction required by the electrochemical cell of Deberry et al was oxidation of ferrous ions to ferric ions. The charging cycle of the iron-vanadium flow battery performs these same reactions at a voltage of just over 1 V, which is significantly lower than the voltage required by the electrochemical cell of Deberry et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the reaction scheme of charging an iron-vanadium flow battery to the system of Staker as modified by Heimala et al and Deberry et al by using a single electrochemical cell to perform the regeneration of the vanadium (II) ions and the ferric ions at a lower voltage than that required by the electrochemical cell of Deberry et al. Claims 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Staker (US 3,958,983 A) in view of Heimala et al (US 2010/0180727 A1), Deberry et al (US 5,705,135 A), Souentie et al (“Temperature, charging current and state of charge effects on iron-vanadium flow batteries operation”) and Blanco et al (US 4,093,526 A). Staker teaches (see abstract, cols. 1 and 2) a process for producing a copper product (e.g. copper, copper sulfide) from a chalcopyrite concentrate comprising providing the chalcopyrite concentrate, contacting the composition with an aqueous solution including a chemical reducing agent (vanadium (II) , chromium (II) or titanium (II) ions), reacting the chalcopyrite concentrate with the chemical reducing agent to reduce copper within the chalcopyrite concentrate (reaction (1) and formation of copper metal noted at col. 2, lines 2-7) and separating a solids reaction product stream and a liquid reaction product (liquid-solid separation techniques) and also separating a gaseous reaction product stream (collection of hydrogen sulfide). The solid phase reaction product that included a copper product, the liquid product included oxidized reducing agent (inherently present since the vanadium, chromium or titanium ions were not recovered in the solid phase), and the gaseous product was hydrogen sulfide. Staker fails to teach the “providing”, “reducing”, “contacting”, “treating”, “recycling”, “contacting”, and “electrowinning” steps as set forth at the end of claim 19. Regarding the “providing”, “reducing”, and “contacting” steps, the oxidized chemical reducing agent, e.g. vanadium or chromium ions having an oxidation state higher than +2, e.g. +3, +4, +5, +6, was inherently present in the liquid phase reaction product of Staker since the vanadium or chromium ions were not recovered in the solid residue. Staker does not teach treatment of the liquid phase in an electrochemical reactor. Heimala et al teach (see abstract, fig. 1, paragraphs [0026], [0027], and [0036]) a process wherein a liquid phase reaction product from a leaching step of a copper bearing material with a solution containing vanadium or chromium ions is provided to an electrochemical device where the oxidized (higher oxidation state) vanadium or chromium ions were reduced (lower oxidation state) at the anode of the electrochemical device and the now reduced oxidized chemical reducing agent is returned to the leaching step for contacting fresh copper bearing material. Therefore, it would have been obvious to one of ordinary skill in the art to have added the “providing”, “reducing”, and “contacting” steps using an electrochemical device as taught by Heimala et al to the process of Staker for the purpose of regenerating the vanadium or chromium chemical reducing agent from its oxidized state for the purpose of reducing the amount of waste generated by the process of Staker by regenerating the low oxidation state vanadium or chromium ion chemical reducing agent. Regarding the “treating” step, Staker and Heimala et al fail to teach the conversion of the hydrogen sulfide product to elemental sulfur being done by reaction with a stream of ferric iron and sending the resulting ferrous iron stream to the electrochemical cell. Deberry et al teach (see abstract, figs. 2 and 3) a process for converting hydrogen sulfide to elemental sulfur comprising reacting the hydrogen sulfide with a stream of ferric iron (Fe+3) which results in the formation of elemental sulfur and ferrous iron (Fe+2). The ferrous iron is then sent to an electrochemical cell (20) where the ferrous iron is oxidized at the anode to form ferric iron which is used for conversion of additional hydrogen sulfide. Note that Deberry et al required a voltage of 5.5 V to drive the regeneration of the ferric ions. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the process for converting hydrogen sulfide to elemental sulfur taught by Deberry et al to the process of Staker because Staker teaches using conventional methods for converting hydrogen sulfide to elemental sulfur and Deberry et al teach that the process operated (see col. 2, lines 52-67) in an ecologically prudent manner with no release of sulfur, no generation of solid waste, while also using a regenerable absorbent with minimal equipment footprint. Regarding the “recycling” step, from Staker, Heimala et al and Deberry et al, there was no recognition that the electrochemical cell of Heimala et al and the electrochemical cell of Deberry et al were the same electrochemical cell as required by the recitation in the “recycling” step of claim 19 (“the electrochemical device” (emphasis added)). In the field of electrochemical cells, iron-vanadium flow batteries are known. See Souentie et al at abstract, fig. 1. During charging of the flow battery, the opposite of reactions (7)-(9) (see section 3.1) occurs. These charging reactions include oxidation of ferrous (Fe+2) iron ions to ferric (Fe+3) iron ions and reduction of vanadium (III) ions to vanadium (II) ions. The overall voltage necessary to drive the reactions was 1.029 V. One of ordinary skill in the art would have recognized that (1) the reaction required by the electrochemical cell of Heimala et al in the context of the process of Staker was reduction of the vanadium (III) ions to vanadium (II) ions and (2) the reaction required by the electrochemical cell of Deberry et al was oxidation of ferrous ions to ferric ions. The charging cycle of the iron-vanadium flow battery performs these reactions at a voltage of just over 1 V, which is significantly lower than the voltage required by the electrochemical cell of Deberry et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to have applied the reaction scheme of charging an iron-vanadium flow battery to the system of Staker as modified by Heimala et al and Deberry et al by using a single electrochemical cell to perform the regeneration of the vanadium (II) ions and the ferric ions at a lower voltage than that required by the electrochemical cell of Deberry et al. Regarding the “contacting” and “electrowinning” steps, Staker teach (see col. 2, lines 19-26) that the solid phase reaction product may be leached with copper chloride with subsequent electrowinning to isolate the copper product. Staker fails to teach the copper chloride leachant being acidic or the electrowinning step regenerating the acid. Blanco et al teach (see fig. 1, abstract, col. 7, lines 11-31) a process for the recovery of copper metal from a copper bearing material, comprising leaching the copper-bearing material with sulfuric acid followed by electrowinning of the pregnant solution which recovered pure copper metal and regeneration of the sulfuric acid which is recycled to the leaching step. Therefore, it would have been obvious to one of ordinary skill in the art to have applied the sulfuric acid leaching step taught by Blanco et al in place of the copper chloride leaching step of Staker by simple substitution according to known techniques because the leaching and electrowinning steps of Blanco et al recovered copper as pure metal while also regenerated the leachant, thereby reducing waste. Regarding claim 20, although not expressed as a molar concentration, the examples of Staker utilized the reducing agent at amounts that fall within the claimed concentration range. For example, Example 2 of Staker included 46 g of VOCl2 in 200 mL of solution. This is about 1/3 of a mole of VOCl2 in 200 mL, or about 0.166 M. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to HARRY D WILKINS III whose telephone number is (571)272-1251. The examiner can normally be reached M-F 9:30am -6:00pm. 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, James Lin can be reached at 571-272-8902. 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. /HARRY D WILKINS III/Primary Examiner, Art Unit 1794
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Prosecution Timeline

Jun 30, 2023
Application Filed
Apr 16, 2026
Non-Final Rejection mailed — §102, §103, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
62%
Grant Probability
81%
With Interview (+18.7%)
3y 0m (~0m remaining)
Median Time to Grant
Low
PTA Risk
Based on 1097 resolved cases by this examiner. Grant probability derived from career allowance rate.

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