Prosecution Insights
Last updated: April 19, 2026
Application No. 18/225,848

Recovery Of Chlorine From Hydrogen Chloride Generated In Carbochlorination Processes

Non-Final OA §112§DP
Filed
Jul 25, 2023
Examiner
IQBAL, SYED TAHA
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Kronos International Inc.
OA Round
1 (Non-Final)
80%
Grant Probability
Favorable
1-2
OA Rounds
2y 9m
To Grant
99%
With Interview

Examiner Intelligence

Grants 80% — above average
80%
Career Allow Rate
659 granted / 823 resolved
+15.1% vs TC avg
Strong +22% interview lift
Without
With
+22.2%
Interview Lift
resolved cases with interview
Typical timeline
2y 9m
Avg Prosecution
28 currently pending
Career history
851
Total Applications
across all art units

Statute-Specific Performance

§101
0.6%
-39.4% vs TC avg
§103
40.1%
+0.1% vs TC avg
§102
24.5%
-15.5% vs TC avg
§112
27.1%
-12.9% vs TC avg
Black line = Tech Center average estimate • Based on career data from 823 resolved cases

Office Action

§112 §DP
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 . 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 8-11 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 8 recites the limitation "the gaseous water" in line 4. There is insufficient antecedent basis for this limitation in the claim. Claims 9-11 are rejected due to the virtue of their dependence on claim 8. Allowable Subject Matter Claims 2-7, 12 and 16-20 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. Claims 8-11 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: Claim 1 requires “A method for recovering chlorine from a carbochlorination process, the method comprising: a) contacting carbonaceous material and chlorine with a metal-bearing feedstock comprising iron to obtain a chloride mixture comprising iron chloride and metal chlorides, b) separating the iron chloride from the chloride mixture, c) subjecting the iron chloride to a hydrolysis step to obtain hydrogen chloride, d) converting at least a portion of the obtained hydrogen chloride into chlorine, and optionally e) using at least a portion of the chlorine obtained in step d) in step a).” US20180105435 teaches a method for treating a waste stream from a titanium dioxide production process to recover valuable components (Abstract and Para [0003]-[0004]). The feedstock comprises of coke (carbonaceous material), unreacted iron and titanium (metal-bearing feedstock) (Para [0005]). The US’5435 reference teaches combining, in unit 1, the unreacted raw material containing iron and titanium with chlorine gas and coke. This produces TiCl4 and FeCl2 (Para [00018] and [00019]). This is considered as the chloride mixture. Thus step a of the claim is taught. The reference further teaches the step of separating TiCl4 in a cyclone separator 2 (See Fig. 1 and Para [0018]). The separation of titanium chloride from the iron chloride is considered to be the same as separating iron chloride from the titanium chloride. The cyclone separator (see unit 2 in Fig. 1) is considered as performing step b. The reference teaches separating out the iron chloride in solution in stream 20. However there is no teaching or suggestion from the prior art regarding “…c) subjecting the iron chloride to a hydrolysis step to obtain hydrogen chloride, d) converting at least a portion of the obtained hydrogen chloride into chlorine, and optionally e) using at least a portion of the chlorine obtained in step d) in step a).” US 20160137498 highlights the need for acid recovery in processes relating to leaching or pickling with acids (Para [0005]). The reference teaches spraying pelletization of metal chloride solution which converts iron chloride into iron oxide and an HCl gas (Para [0018]). However there is no teaching or suggestion from the prior art regarding “a) contacting carbonaceous material and chlorine with a metal-bearing feedstock comprising iron to obtain a chloride mixture comprising iron chloride and metal chlorides, b) separating the iron chloride from the chloride mixture… d) converting at least a portion of the obtained hydrogen chloride into chlorine, and optionally e) using at least a portion of the chlorine obtained in step d) in step a).” Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.” Double Patenting The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969). A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13. The USPTO Internet website contains terminal disclaimer forms which may be used. Please visit www.uspto.gov/patent/patents-forms. The actual filing date of the application in which the form is filed determines what form (e.g., PTO/SB/25, PTO/SB/26, PTO/AIA /25, or PTO/AIA /26) should be used. A web-based eTerminal Disclaimer may be filled out completely online using web-screens. An eTerminal Disclaimer that meets all requirements is auto-processed and approved immediately upon submission. For more information about eTerminal Disclaimers, refer to www.uspto.gov/patents/apply/applying-online/eterminal-disclaimer. Claims 1, 13, 14 and 15 provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1, 7, 9 and 11 of copending Application No. 18/386903 (reference application). Although the claims at issue are not identical, they are not patentably distinct from each other because they both require producing and separating metal chlorides then recovering chlorine from HCl that is extracted from the metal chlorides. This is a provisional nonstatutory double patenting rejection because the patentably indistinct claims have not in fact been patented. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to SYED TAHA IQBAL whose telephone number is (571)270-5857. The examiner can normally be reached M-F; 7-5. 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) 270-3591. 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. /SYED T IQBAL/ Examiner, Art Unit 1736 /ANTHONY J ZIMMER/ Supervisory Patent Examiner, Art Unit 1736
Read full office action

Prosecution Timeline

Jul 25, 2023
Application Filed
Jan 19, 2026
Non-Final Rejection — §112, §DP (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
80%
Grant Probability
99%
With Interview (+22.2%)
2y 9m
Median Time to Grant
Low
PTA Risk
Based on 823 resolved cases by this examiner. Grant probability derived from career allow rate.

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