Prosecution Insights
Last updated: July 17, 2026
Application No. 18/467,728

METHOD FOR PREPARING COBALT SULFATE SALT

Non-Final OA §112
Filed
Sep 15, 2023
Priority
Mar 16, 2021 — RE 10-2021-0034110 +1 more
Examiner
ZHANG, KELING NMN
Art Unit
1732
Tech Center
1700 — Chemical & Materials Engineering
Assignee
SK Inc.
OA Round
1 (Non-Final)
66%
Grant Probability
Favorable
1-2
OA Rounds
5m
Est. Remaining
84%
With Interview

Examiner Intelligence

Grants 66% — above average
66%
Career Allowance Rate
136 granted / 206 resolved
+1.0% vs TC avg
Strong +18% interview lift
Without
With
+18.5%
Interview Lift
resolved cases with interview
Typical timeline
3y 3m
Avg Prosecution
47 currently pending
Career history
264
Total Applications
across all art units

Statute-Specific Performance

§103
86.3%
+46.3% vs TC avg
§102
5.7%
-34.3% vs TC avg
§112
6.6%
-33.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 206 resolved cases

Office Action

§112
DETAILED ACTION Claims 1-13 were subject to restriction requirement mailed on 02/25/2026. Applicant filed a response, and elected Group I, claims 1-12, and withdrew claim 13, without traverse on 04/23/2026. Claims 1-12 are pending, and claim 13 is withdrawn. Claims 12 are rejected. Election/Restrictions Applicant’s election without traverse of Group I, claims 1-12 in the reply filed on 04/23/2026 is acknowledged. Claim 13 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 04/23/2026. Claim Interpretation Claim 1, lines 6-7, recites “filtering the first solution together with a first purging to produce a first cobalt sulfate salt” (emphasis added). The examiner interprets that the phrase “a first cobalt sulfate salt” refers to crystals produced from the evaporation crystallization and filtering of the first solution together with a first purging. Claim 1, lines 11-12, recites “filtering the second solution together with a second purging to produce a second cobalt sulfate salt” (emphasis added). The examiner interprets that the phrase “a second cobalt sulfate salt” refers to crystals produced from the evaporation crystallization and filtering of the second solution together with a second purging. Claim Objections Claims 1, 8 and 12 are objected to because of the following informalities: Claim 1, lines 11-12, it is suggested to amend “a second cobalt sulfate salt” to “the cobalt sulfate salt” to be consistent with the phrase “a cobalt sulfate salt” recited in Claim 1, line 1. Claim 8, line 2, it is suggested to amend “second purging” to “second purging based on a weight of the second solution” to ensure clarity. Claim 8, line 3, it is suggested to amend “first purging” to “first purging based on a weight of the first solution” to ensure clarity. Claim 12, line 3, it is suggested to amend “the filtration” to “filtration” to ensure clarity. Appropriate correction is required. 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 1-12 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, lines 6-7, recites a phrase “filtering the first solution together with a first purging to produce a first cobalt sulfate salt”. However, it is unclear what the phrase refers to, as it is unclear what “together with a first purging” refers to, i.e., removal of a fraction of the first solution prior filtering the first solution, washing the first cobalt sulphate salt while filtering the first solution, etc. The examiner interprets that the phrase refers to “removal of a fraction of the first solution prior filtering the first solution” according to specification [0044]. Interpretation is speculative. Clarification is requested. Claim 1, lines 11-12, recites a phrase “filtering the second solution together with a second purging to produce a second cobalt sulfate salt”. However, it is unclear what the phrase refers to for the same set forth above, i.e., removal of a fraction of the second solution prior filtering the second solution, washing the second cobalt sulphate salt while filtering the second solution, etc. The examiner interprets that the phrase refers to “removal of a fraction of the second solution prior filtering the second solution” according to specification [0044]. Interpretation is speculative. Clarification is requested. Regarding dependent claims 2-12, these claims does not remedy the deficiencies of parent claim 1 noted above, and are rejected for the same rationale. Allowable Subject Matter Claims 1-12 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. The present claims are allowable over the “closest” prior art EOM, KR 20180032789A (EOM). The examiner has provided a machine translation of EOM, KR 20180032789A (EOM). The citation of the prior art set forth below refers to the machine translation. EOM discloses a method for crystallizing cobalt sulfate hydrate, comprising the following steps: mixing an aqueous solution of CoSO4 with an alcohol to form a mixture; precipitating the mixture to obtain precipitated cobalt sulfate cobalt hydrate; and crystallizing the cobalt sulfate hydrate by evaporation under reduced pressure However, EOM does not disclose or suggest the aqueous solution of CoSO4 contains an aqueous solution of sulfuric acid; filtering the first solution together with a first purging to produce a first cobalt sulfate salt; forming an aqueous solution containing the first cobalt sulfate salt; producing a second solution by a cooling crystallization of the aqueous solution containing the first cobalt sulfate salt; and filtering the second solution together with a second purging to produce a second cobalt sulfate salt, as presently claimed. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to KELING ZHANG whose telephone number is (571)272-8043. The examiner can normally be reached Monday - Friday: 9:00am-5:00pm 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, Ching-Yiu Fung can be reached at 571-270-5713. 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. /KELING ZHANG/ Primary Examiner Art Unit 1732
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Prosecution Timeline

Sep 15, 2023
Application Filed
Jun 30, 2026
Non-Final Rejection mailed — §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

1-2
Expected OA Rounds
66%
Grant Probability
84%
With Interview (+18.5%)
3y 3m (~5m remaining)
Median Time to Grant
Low
PTA Risk
Based on 206 resolved cases by this examiner. Grant probability derived from career allowance rate.

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