Prosecution Insights
Last updated: April 19, 2026
Application No. 17/886,924

APPARATUS FOR ELECTRO-CHEMICAL EXTRACTION OF ELEMENTAL LEAD FROM DROSS

Non-Final OA §103
Filed
Aug 12, 2022
Examiner
CONTRERAS, CIEL P
Art Unit
1794
Tech Center
1700 — Chemical & Materials Engineering
Assignee
VERDEEN CHEMICALS INC.
OA Round
3 (Non-Final)
54%
Grant Probability
Moderate
3-4
OA Rounds
3y 0m
To Grant
87%
With Interview

Examiner Intelligence

Grants 54% of resolved cases
54%
Career Allow Rate
401 granted / 742 resolved
-11.0% vs TC avg
Strong +33% interview lift
Without
With
+33.3%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
67 currently pending
Career history
809
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
41.2%
+1.2% vs TC avg
§102
19.5%
-20.5% vs TC avg
§112
31.7%
-8.3% vs TC avg
Black line = Tech Center average estimate • Based on career data from 742 resolved cases

Office Action

§103
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 . 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 25 January 2026 has been entered. Claim Rejections - 35 USC § 103 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. 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 8-17 and 20-27 are rejected under 35 U.S.C. 103 as being unpatentable over Foreign Patent Document No. WO 2016/130675 A1 to Tyagi et al. (Tyagi) in view of US 2006/0169590 A1 to Hebditch et al. (Hebditch). As to claims 8, 9 and 15, Tyagi teaches a system for recovery of near-pure lead from an impure lead dross from a used lead-acid battery, the system comprises components for combining the impure lead dross with a sodium hydroxide electrolyte, thus a subsystem that is capable of performing the functional language of “combining the dross with an electrolyte to form a slurry, said slurry comprising a mixture of the dross and the electrolyte such that the electrolyte does not dissolve the target metal material before performing solid-state electrolysis”, a component for performing electrolysis on a mixture, thus a subsystem for performing the functional language of “performing electrolysis on the slurry to form target m metal deposits and residual components” and a component specifically configured for mechanically separating the lead from the electrolyte and the residual components without smelting (Paragraphs 0027-0031 and 0044-0045; MPEP 2114). However, Tyagi is silent as to the specific configuration of the electrolyzer for performing the electrolysis. However, Hebditch also discusses the electrolytic recovery of metal from compositions containing metals (Paragraph 0001) and teaches that an improved electrolyzer for this recovery in terms of the provision of a large surface area per unit volume and an ability to allow fully continuous operation comprises a horizontal cathode configuration (Paragraphs 0014, 0030 and 0033). Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to utilize an electrolyzer as in Hebditch with a horizontal cathode in order to use an improved configuration in terms of surface area per unit volume and continuous operation as taught by Hebditch. Hebditch teaches that the electrolyzer comprising the horizontal cathode (3) has a surface onto which an electrolytic slurry may be emplaced for electrolysis (in electrolyte space (4)), an anode (2) having a horizontal surface suspended above the horizontal cathode (3) for physically engaging the electrolytic slurry for electrolysis (Paragraph 0058; Figure 1). As to claims 10 and 16, the combination of Tyagi and Hebditch teaches the system of claim 8. Tyagi further teaches that the system is configured for adding supplemental chemicals to the slurry prior to performing the solid-state electrolysis, i.e. solubility enhancers and gelling agents, thus a subsystem of some sort for performing this step (Paragraph 0039 and 0049). As to claims 11 and 20, the combination of Tyagi and Hebditch teaches the system of claim 10. The system of the combination would be capable of operating on any number of supplied compounds (MPEP 2114). Tyagi further specifically teaches operation on near-pure metal that elemental lead and dross that comprises lead monoxide (Paragraphs 0027 and 0038). As to claim 12, the combination of Tyagi and Hebditch teaches the system of claim 11. The system of the combination would be capable of performing solid-state electrolysis, i.e. electrolysis when solid materials are present (MPEP 2114). As to claim 13, the combination of Tyagi and Hebditch teaches the system of claim 12. Tyagi further teaches that the separating comprises pressing, compacting, the target metal (Paragraph 0044). As to claim 14, the combination of Tyagi and Hebditch teaches the system of claim 11. The apparatus of the combination would be capable of receiving any number of compounds including a lead monoxide that had been leached with a solvent (MPEP 2114). Tyagi further specifically teaches that prior to combining the lead monoxide in the dross the lead dioxide is leached into a solution with a solvent, i.e. desulfurization occurs (Paragraphs 0035-0038). As to claim 17, the combination of Tyagi and Hebditch teaches the apparatus of claim 15. Hebditch further teaches that the apparatus comprises a removing mechanism (5) for removing, from the horizontal cathode (3) an end product resulting from electrolysis (Paragraph 0058; Figure 1). As to claims 21, 25 and 27, Tyagi teaches a system for recovery of near-pure lead from an impure lead dross from a used lead-acid battery, the system comprises components for combining the impure lead dross with a sodium hydroxide electrolyte, thus a subsystem that is capable of performing the functional language of “combining the dross with an electrolyte to form a slurry wherein the electrolyte does not dissolve the target metal material before performing solid-state electrolysis”, a component for performing electrolysis on a mixture, thus a subsystem for performing the functional language of “for forming near-pure target metal deposits and residual components” and a component specifically configured for mechanically separating the lead from the electrolyte and the residual components without smelting, this separation means comprising a melter of some sort for melting, the lead target metal, and a transformer of some fort for solid pressing the target metal (Paragraphs 0027-0031 and 0044-0045; MPEP 2114). However, Tyagi is silent as to the specific configuration of the electrolyzer for performing the electrolysis. However, Hebditch also discusses the electrolytic recovery of metal from compositions containing metals (Paragraph 0001) and teaches that an improved electrolyzer for this recovery in terms of the provision of a large surface area per unit volume and an ability to allow fully continuous operation comprises a horizontal cathode configuration (Paragraphs 0014, 0030 and 0033). Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to utilize an electrolyzer as in Hebditch with a horizontal cathode in order to use an improved configuration in terms of surface area per unit volume and continuous operation as taught by Hebditch. Hebditch teaches that the electrolyzer comprising the horizontal cathode (3) has a surface onto which an electrolytic slurry may be emplaced for electrolysis (in electrolyte space (4)), an anode (2) having a horizontal surface suspended above the horizontal cathode (3) for physically engaging the electrolytic slurry for electrolysis (Paragraph 0058; Figure 1). As to claim 22, the combination of Tyagi and Hebditch teaches the device of claim 21. The system of the combination would be capable of operating on any number of supplied compounds (MPEP 2114). Tyagi further specifically teaches operation on near-pure metal that elemental lead and dross that comprises lead monoxide (Paragraphs 0027 and 0038). As to claim 23, the combination of Tyagi and Hebditch teaches the device of claim 21. Tyagi further teaches that the system is configured for adding supplemental chemicals to the slurry prior to performing the solid-state electrolysis, i.e. solubility enhancers and gelling agents, thus a means of some sort for performing this step (Paragraph 0039 and 0049). AS to claim 24, the combination of Tyagi and Hebditch teaches the device of claim 21. The system of the combination would be capable of performing solid-state electrolysis, i.e. electrolysis when solid materials are present (MPEP 2114). As to claim 26, the combination of Tyagi and Hebditch teaches the device of claim 21. The apparatus of the combination would be capable of receiving any number of compounds including a lead monoxide that had been leached with a solvent (MPEP 2114). Tyagi further specifically teaches that prior to combining the lead monoxide in the dross the lead dioxide is leached into a solution with a solvent, i.e. desulfurization occurs (Paragraphs 0035-0038). Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tyagi and Hebditch as applied to claim 15 above, and further in view of US Patent No. 3,562,135 to Marincek (Marincek). As to claim 18, the combination of Tyagi and Hebditch teaches the apparatus of claim 15. Hebditch fails to teach that the horizontal anode comprises a plurality of vents through which gaseous compounds pass; however, Tyagi does teach that hydrogen is generated during operation of the apparatus (Paragraph 0029). Marincek also discloses horizontal electrolysis cells with gaseous by product and teaches that the anode is formed with vents (porous, perforated or reticulated) in order to allow gas to pass therethrough for collection for later use (Column 2, Lines 66-71). Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to modify the anode of Hebditch with vents in order to allow the byproduct hydrogen to pass therethrough for collection as taught by Marincek. Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over the combination of Tyagi and Hebditch as applied to claim 15 above, and further in view of US Patent No. 3,891,741 to Carlin et al. (Carlin). As to claim 19, the combination of Tyagi and Hebditch teaches the apparatus of claim 15. The combination teaches that electrolysis is performed and thus that the apparatus includes some source of power; however, the combination is silent as to the specific source of power. However, Carlin also discusses electrolytic recovery of metal products and teaches that an effective power supply for the electrolysis comprises a power controller connected to a direct current power supply, with the benefit of regulating the cathode potential (Column 7, Lines 18-25; Column 7, Line 52 to Column 8, Line 13). Therefore, it would have been obvious to one of ordinary skill in the art at the time of filing to modify the apparatus of the combination with the a DC power source and power controller in order to effectively power the electrolysis with the benefit of regulating the cathode potential as taught by Carlin. Response to Arguments Applicant's arguments filed 3 July 2025 have been fully considered but they are not persuasive. Applicants argue that Tyagi fails to teach that the target metal does not dissolve in the electrolyte before performing solid-state electrolysis. However, it is important to note that this limitation is a functional limitation. Apparatus claims must be distinguished from the prior art in terms of structure rather than function. Functional limitations do not serve to further limit apparatus claims beyond imparting the limitation that the apparatus is capable of performing the claimed function. The Examiner maintains that the apparatus of the combination would be capable of receiving the components in the specific concentrations to form a slurry and operating in solid state electrolysis on the slurry (MPEP 2114). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CIEL P Contreras whose telephone number is (571)270-7946. The examiner can normally be reached M-F 9 AM to 4 PM. 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 on 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. /CIEL P CONTRERAS/Primary Examiner, Art Unit 1794
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Prosecution Timeline

Aug 12, 2022
Application Filed
Jan 29, 2025
Non-Final Rejection — §103
Jul 03, 2025
Response Filed
Jul 22, 2025
Final Rejection — §103
Jan 25, 2026
Request for Continued Examination
Jan 29, 2026
Response after Non-Final Action
Mar 24, 2026
Non-Final Rejection — §103 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

3-4
Expected OA Rounds
54%
Grant Probability
87%
With Interview (+33.3%)
3y 0m
Median Time to Grant
High
PTA Risk
Based on 742 resolved cases by this examiner. Grant probability derived from career allow rate.

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