Prosecution Insights
Last updated: April 19, 2026
Application No. 18/249,244

BIO-LEACHING COMPOSITIONS AND METHODS FOR MINING METALS

Non-Final OA §102§103
Filed
Apr 15, 2023
Examiner
BAUM, ZACHARY JOHN
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Locus Solutions Ipco LLC
OA Round
1 (Non-Final)
79%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
93%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
86 granted / 109 resolved
+13.9% vs TC avg
Moderate +14% lift
Without
With
+14.0%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
26 currently pending
Career history
135
Total Applications
across all art units

Statute-Specific Performance

§103
41.4%
+1.4% vs TC avg
§102
21.0%
-19.0% vs TC avg
§112
28.4%
-11.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 109 resolved cases

Office Action

§102 §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 . Election/Restrictions Applicant's election with traverse of the following Claim and Species Groups in the reply filed on December 2nd, 2025 is acknowledged: Claim Group: Group I, claims 1-2 and 4-8; Species Group I: sulfuric acid and ferric chloride; and Species Group II: Bacillus sp. The traversal is on the following grounds: Group I is allegedly a special technical feature required to practice the methods of both Groups II and III; and The species are allegedly searchable together. Ground (i) is not found persuasive because no argument is provided to rebut the finding that Group I is not a special technical feature presented on Page 4, lines 1-7 of the Office Action dated October 3rd, 2025. Ground (ii) is not found persuasive because establishment of a search burden is used to determine whether the Office may require restriction in national applications filed under 35 U.S.C. 111(a). The analysis used to determine whether the Office may require restriction differs in national stage applications submitted under 35 U.S.C. 371 (unity of invention analysis) as compared to national applications filed under 35 U.S.C. 111(a) (independent and distinct analysis). See MPEP Chapter 1800, in particular MPEP § 1850, § 1875, and § 1893.03(d), for a detailed discussion of unity of invention under the Patent Cooperation Treaty (PCT). The requirement is still deemed proper and is therefore made FINAL. Claims 9-10, 12-13, 15-18, 21-23, 25-26, and 39-40 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to nonelected inventions, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on December 2nd, 2025. Claim Interpretation Claims 1-2 and 4-8 contain limitations directed to a “bioleaching composition”. The instant Specification states, “As used herein, ‘leaching’ refers to the process by which a metal is separated from a metal source, such as, for example, ore, mine tailings, slag and/or electronic waste from, for example, batteries and circuits by aqueous solutions including by, for example, cyanide leaching, ammonia leaching, alkali leaching, or acid leaching” (Specification, Page 17, lines 13-16, emphasis added). The term “bioleaching” is not given an explicit definition in the instant Specification but is discussed at length. As best understood by the Examiner, a “bioleaching composition” is not required to contain a biological component, but could contain: Biomolecules (see instant Specification, Page 1, lines 25-32 and Example 1, Page 26, lines 19-31), and/or Microorganisms which produce compounds that can directly or indirectly solubilize metals (instant Specification, Page 3, lines 25-29, “In some embodiments, methods of extracting a target metal from ore are provided wherein an ore in a particulate state is combined with a microorganism and/or bioleaching composition according to the subject invention to form a liquid slurry. The microbes can be live (or viable), or inactive at the time of application. In certain embodiments, the microorganisms can grow in situ and produce active compounds (e.g., metabolites) that can directly or indirectly solubilize metals.”) In accordance with the definition of “leaching” and the above interpretation of “bioleaching” derived from the instant Specification, a “bioleaching composition” is interpreted to be a composition including a microorganism or biomolecule component that could reasonably be construed by a person having ordinary skill in the art to be capable of separating a metal from a metal source, as individual claims are given their broadest reasonable interpretation in light of the specification. See MPEP § 2111. Because the provided definition of “leaching” does not limit the metal source, waste, or leaching process to the examples it cites, “leaching” will not be interpreted to be limited to these examples or provided embodiments. Claim Rejections - 35 USC § 102 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 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, 4, and 6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Li (CN 112625689 A, 2021) (the attached machine translation is referenced below). Regarding claim 1, Li teaches a bioleaching composition comprising an aqueous solution of a biosurfactant (Li, [0045], sophorolipid) and at least one metal solubilizing agent (Li, [0045], ethylenediamine disuccinic acid (degradable chelating agent)). Regarding claim 2, Li teaches the bioleaching composition according to claim 1, wherein the biosurfactant is a sophorolipid biosurfactant (SLP) (Li, [0045]). Regarding claim 4, Li teaches the bioleaching composition according to claim 1, as discussed above, comprising metal solubilizing agents including acid (Li, [0045], ethylenediamine disuccinic acid) and oxidant (Li, [0045], iron trichloride is ferric chloride; instant claim 6 indicates that ferric chloride is an oxidant). Regarding claim 6, Li teaches the bioleaching composition according to claim 4, as discussed above, comprising ferric chloride (Li, [0045], iron trichloride). 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. 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 1-2, 4-5, and 7-8 are rejected under 35 U.S.C. 103 as being unpatentable over '076 (U.S. 2020/0340076 A1). Regarding claim 1, ‘076 teaches a bioleaching (‘076, [0045]) composition (‘076, [0073]) comprising a liquid solution (‘076, [0144]) of a biosurfactant (‘076, [0073], biological leaching reagent comprising one or more microorganisms and/or microbial growth by-products; [0075], “In one embodiment, the microbial growth by-products are biosurfactants.”) and at least one metal solubilizing agent (‘076, [0082], enhancing components which can include additional microbial cultures; as leaching is solubilization of metals, enhancing leaching means promoting metal dissolution). ‘076 does not explicitly teach that the solution is an aqueous solution. However, as ‘076 considers leaching to be a process which takes place in aqueous media (‘076, [0002]), it would have been obvious for the solution of the bioleaching composition in ‘076 to be an aqueous solution. Regarding claim 2, ‘076 renders the bioleaching composition according to claim 1 obvious, as discussed above, wherein the biosurfactant is a sophorolipid biosurfactant (‘076, [0077], sophorolipids are particularly preferable). Regarding claims 4 and 5, ‘076 renders the bioleaching composition according to claim 1 obvious, as discussed above, comprising an additional component selected from a list including sulfuric acid (‘076, [0137]). It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have selected sulfuric acid as an additional component in the bioleaching composition of ‘076. The selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See In re Leshin, 125 USPQ 416 (CCPA 1960), Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945), and MPEP § 2144.07. In the instant case, sulfuric acid was known to be suitable as a pH adjusting agent. Despite not explicitly stating that sulfuric acid is used as a “metal solubilizing agent”, sulfuric acid would necessarily be a metal solubilizing agent, as it would be used to adjust the pH to promote dissolution of metals, i.e., leaching. Regarding claim 7, ‘076 renders the bioleaching composition according to claim 1 obvious, as discussed above, wherein the metal solubilizing agent comprises a microorganism (076, [0082], enhancing components which can include additional microbial cultures (microorganisms); as leaching is solubilization of metals, enhancing leaching means promoting metal dissolution). Regarding claim 8, ‘076 renders the bioleaching composition according to claim 7 obvious, as discussed above, wherein the microorganism is selected from a list including Bacillus subtilis (‘076, [0083]), a Bacillus sp. It would have been obvious to a person having ordinary skill in the art before the effective filing date of the invention to have further selected Bacillus subtilis as the microorganism in the bioleaching composition of ‘076, as ‘076 teaches that this is a suitable option for the microorganism (‘076, [0083]). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to ZACHARY J. BAUM whose telephone number is (571)270-0895. The examiner can normally be reached Monday-Friday 8:30-5:00. 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, Anthony Zimmer can be reached at 571-270-3590. 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. /ZACHARY JOHN BAUM/Examiner, Art Unit 1736 /ANTHONY J ZIMMER/Supervisory Patent Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Apr 15, 2023
Application Filed
Feb 23, 2026
Non-Final Rejection — §102, §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

1-2
Expected OA Rounds
79%
Grant Probability
93%
With Interview (+14.0%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 109 resolved cases by this examiner. Grant probability derived from career allow rate.

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