Prosecution Insights
Last updated: April 19, 2026
Application No. 18/272,834

RECOVERY OF METAL FROM LEACH PROCESSING

Non-Final OA §102§112
Filed
Jul 18, 2023
Examiner
MCGUTHRY BANKS, TIMA MICHELE
Art Unit
1733
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Extrakt Process Solutions LLC
OA Round
2 (Non-Final)
82%
Grant Probability
Favorable
2-3
OA Rounds
2y 6m
To Grant
83%
With Interview

Examiner Intelligence

Grants 82% — above average
82%
Career Allow Rate
941 granted / 1154 resolved
+16.5% vs TC avg
Minimal +2% lift
Without
With
+1.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 6m
Avg Prosecution
65 currently pending
Career history
1219
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
40.3%
+0.3% vs TC avg
§102
19.4%
-20.6% vs TC avg
§112
33.0%
-7.0% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1154 resolved cases

Office Action

§102 §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 . Information Disclosure Statement The information disclosure statement (IDS) submitted on 12/17/2025 was filed after the mailing date of the non-final rejection on 09/18/2025. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner. Allowable Subject Matter The indicated allowability of claim 15 is withdrawn in view of the newly discovered reference(s) to Kappes in “Chloride Leaching for Silver, Copper, Lead & Anitmony [sic].” Rejections based on the newly cited references follow. Status of Claims Claims 1, 4-6, 11, 14-16, and 20 are currently amended, Claims 2, 8 and 12 are canceled, Claims 3 and 10 are as originally filed, Claims 7, 8, 13, and 17-19 are as previously presented, and Claims 21-23 are new. 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 1-23 are 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 1 recites the dosage of the water-soluble flocculating polymer is no less than 0.005%, but the dosage is defined as the weight of the water-soluble flocculating polymer to weight of solids in the feed slurry, or weight ratio. It is unclear how “0.005%” relates to a weight ratio, since the individual weights are not based on percentages. Claim 1 recites “on a solution basis” in parentheses. If applicant intends to define “0.4 wt%” as the amount of indifferent salt in the residual leach solution, then the parentheses should be removed. Otherwise, their use reads as optional. Claim 15 recites the dosage of the water-soluble flocculating polymer is no less than 0.005 to 0.04%, but the dosage is defined as the weight of the water-soluble flocculating polymer to weight of solids in the feed slurry, or weight ratio. It is unclear how “0.005%” relates to a weight ratio, since the individual weights are not based on percentages. Claim 15 recites “on a solution basis” in parentheses. If applicant intends to define “1 wt%” as the amount of indifferent salt in the residual leach solution, then the parentheses should be removed. Otherwise, their use reads as optional. Claim 21 recites “on a solution basis” in parentheses. If applicant intends to define “0.4 wt%” as the amount of indifferent salt in the residual leach solution, then the parentheses should be removed. Otherwise, their use reads as optional. Claim 22 recites the limitation "the alkali chloride" in 7. There is insufficient antecedent basis for this limitation in the claim. Claim 22 recites the limitation "the indifferent salt dissolved in the leach medium" in line 9. There is insufficient antecedent basis for this limitation in the claim. Claim 22 recites “on a solution basis” in parentheses. If applicant intends to define “1 wt% to 10 wt%” as the amount of indifferent salt in the leach medium, then the parentheses should be removed. Otherwise, their use reads as optional. Claim 23 recites the dosage of the water-soluble flocculating polymer is no less than 0.005 to 0.04%, but the dosage is defined as the weight of the water-soluble flocculating polymer to weight of solids in the feed slurry, or weight ratio. It is unclear how “0.005%” relates to a weight ratio, since the individual weights are not based on percentages. Claim 23 recites “on a solution basis” in parentheses. If applicant intends to define “2 wt% to 4 wt%” as the amount of indifferent salt in the leach medium, then the parentheses should be removed. Otherwise, their use reads as optional. Claims dependent on any of the rejected claims are likewise rejected under this statute. Claim Rejections - 35 USC § 102 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim 21 is rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kappes. Kappes chloride leaching as represented below in the annotated flowsheet: PNG media_image1.png 940 744 media_image1.png Greyscale The tailings (page 6) read on leach solids residue. The tailings are separated from the pregnant solution by filtration and metal salts are recovered (page 6). For batch scale tests, 15 g FeCl3/L (indifferent salt) is required (page 3) or 1.5 wt%, which reads on at least 0.4 wt% on a solution basis. Kappes teaches treating 600 tonnes of ore per day in a 45% solids slurry by weight (page 3). The solids concentration is therefore greater than 10 wt% solids. Kappes anticipates the claimed invention. Allowable Subject Matter Claims 1, 3-7, 9-11, and 13-20 would be allowable if rewritten or amended to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. Claims 22 and 23 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. The following is a statement of reasons for the indication of allowable subject matter: AU 2067002 A (AU ‘002) teaches a polymer flocculant for sulfuric acid leaching separation. The polymer flocculant is a water-soluble high molecular weight copolymer such as containing 50% by mole or more of (meth)acrylamide or its derivative in the form of an aqueous salt solution (page 3). The first step of the recovery method is to concentrate an aqueous slurry of pulverized ore. The second step of the recovery method is leaching in sulfuric acid using a polymer flocculant (page 4). The polymer flocculant may contain optional components other than NaCl included salts (page 7). Regarding Claims 1, 15, 21 and 22, there is no basis to suggest using the polymer flocculant for sulfuric acid leaching in AU ‘002 in the HCl leaching in Kappes. Response to Arguments Applicant’s arguments with respect to claim 21 has been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to Tima M. McGuthry-Banks whose telephone number is (571)272-2744. The examiner can normally be reached Monday through Friday, 7:30 am to 4:00 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, Keith D. 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. Tima M. McGuthry-Banks Primary Examiner Art Unit 1733 /TIMA M. MCGUTHRY-BANKS/Primary Examiner, Art Unit 1733
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Prosecution Timeline

Jul 18, 2023
Application Filed
Sep 16, 2025
Non-Final Rejection — §102, §112
Dec 17, 2025
Response Filed
Jan 27, 2026
Non-Final Rejection — §102, §112 (current)

Precedent Cases

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

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Prosecution Projections

2-3
Expected OA Rounds
82%
Grant Probability
83%
With Interview (+1.9%)
2y 6m
Median Time to Grant
Moderate
PTA Risk
Based on 1154 resolved cases by this examiner. Grant probability derived from career allow rate.

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