Prosecution Insights
Last updated: April 19, 2026
Application No. 18/255,561

PYROLYTIC EXTRACTION OF HYDROCHLORIC ACID FROM MAGNESIUM SALT MIXTURES, ESPECIALLY BITTERNS

Non-Final OA §102§112
Filed
Jun 01, 2023
Examiner
NGUYEN, CAM N
Art Unit
1736
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Luna Innovations Incorporated
OA Round
1 (Non-Final)
85%
Grant Probability
Favorable
1-2
OA Rounds
2y 8m
To Grant
97%
With Interview

Examiner Intelligence

Grants 85% — above average
85%
Career Allow Rate
1070 granted / 1260 resolved
+19.9% vs TC avg
Moderate +12% lift
Without
With
+11.9%
Interview Lift
resolved cases with interview
Typical timeline
2y 8m
Avg Prosecution
38 currently pending
Career history
1298
Total Applications
across all art units

Statute-Specific Performance

§101
0.7%
-39.3% vs TC avg
§103
30.5%
-9.5% vs TC avg
§102
31.0%
-9.0% vs TC avg
§112
27.6%
-12.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1260 resolved cases

Office Action

§102 §112
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 . DETAILED ACTION Status of Application 1. This application is a 371 of PCT/US2021/057821, which was filed on 11/03/2021. Claims 1-16 were originally presented in this application for examination. Claims 1-16 are currently pending in this application and under consideration. Specification 2. The examiner has not checked the specification to the extent necessary to determine the presence of all possible minor errors (grammatical, typographical, and idiomatic). Cooperation of the applicant(s) is requested in correcting any errors of which applicant(s) may become aware of in the specification, in the claims and in any further amendment(s) that applicant(s) may file. Applicant(s) is also requested to complete the status of the copending applications referred to in the specification by their Attorney Docket Number or Application Serial Number, if any. The status of the parent application(s) and/or any other application(s) cross-referenced to this application, if any, should be updated in a timely manner. Claim Objections 3. Claim 15 is objected to because of the following informalities: In line 2, “magnesium carbona” is not a known chemical term. Appropriate correction is required. Claim Rejections - 35 USC § 112 (Second Paragraph) 4. 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 1-16 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. A. Claim 1 recites a pyrolysis step of magnesium salts which leads to magnesium hydroxide. Pyrolysis of magnesium salts is well known by the prior art, but the pyrolysis leads to MgO which can be then further processed to magnesium hydroxide. A pyrolysis of magnesium salts leading directly to magnesium hydroxide seems not to be chemically and physically possible. In consequence, claim 1 seems to lacking essential features for essential procedural steps needed to be carried out in order to arrive at magnesium hydroxide. In absence of further evidence, it is consequence assumed, that in fact MgO is obtained, not Mg(OH)2. B. Regarding claim 1, line 6, the two phrases “a sufficient temperature” and “a sufficient time” do not particularly point out the temperature and time for the claimed process, thus renders the claim unclear as to what temperature is used in the pyrolysis step of the claimed process. C. Regarding claims 2-4, the claims recite “magnesium ions in tetrahydrate or lower state/monohydrate to trihydrate state”. These expressions lack clarity, as no real chemical meaning can be associated with these definitions, thereby renders the scope of the claims undeterminable. It is not clear, what the “state” should represent or encompass. When applying the commonly known chemical definition, a magnesium monohydrate salt is indicating the associated water with the salt. A “state” is rather directed to the oxidation state. The description is silent in regard to further clarification. The only examples disclosed are using MgCl2 and MgSO4 as starting materials for the pyrolysis, which is also considered for the search. D. Regarding claim 8, the claim recites combustion gas which is “stoichiometrically lean”. This term renders the claim unclear, in the sense, that the real intended scope of the claim cannot be determined, “lean-burn” is a well-known term, but not in connection with “stoichiometrically”. E. Regarding claims 14-16, these claims depend on claim 9 and refer to “the insoluble magnesium”. Nevertheless, claim 9 is silent in regard to a “insoluble magnesium”. Thus, the claims are rendered unclear. Claim Rejections - 35 USC § 102(a)(1) 5. 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. Claim(s) 1-9 is/are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN 104 773 744 A, hereinafter “CN ‘744”. CN ‘744 discloses the preparation of high purity MgO and hydrochloric acid simultaneously. The steps including using a mixture of alkali metal chlorides including MgCl2, filtering and removing impurities, re-crystallization of MgCl2, followed by a drying step to remove crystallization water, followed by pyrolysis using a pyrolysis furnace with tail gas at 550oC-750oC in order to obtain MgO and HCl, which is separated and processed to hydrochloric acid (see [0009] - [0043], Examples, and claims). Regarding claim 1, CN ‘744 teaches the same process as claimed and including all of the steps (a) thru (d) as recited in the instant claim, thus the claim is anticipated by the reference. Regarding claims 2-4, CN ‘744 appears to teach the claimed initial dehydration step as further included in step (a) of the claimed process because he teaches to filter the raw material liquid, remove insoluble impurities, then concentrate to obtain saturated liquid (see page 12, [0013] of CN ‘744). Regarding claims 5-8, the reference teaches to use tail gas in the pyrolysis step for heating the salts mixture, which meets the claim limitations on the heated gas. A specific Example 2 of the reference teaches the mixture was pyrolyzed at 600oC for 30 mins, which meets the claimed temperature range of “about 300oC to about 900oC” and a time of “between about 5 to about 80 mins”. Regarding claim 9, the instant claim further defines that “step (c) comprises washing the solid pyrolyzed mixed salt stream in seawater to wash any of the soluble salt components from the insoluble magnesium hydroxide”. CN ‘744 discloses the solution in step (a) remaining after the seawater, etc. are dried for salt, etc. (see page 13, [0021], thus it is considered using seawater to wash the solids is not inventive since using the same water to ensure resulting in high purity solids. Citations 6. The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. All references are cited for related art. See PTO-892 Form prepared. Conclusion 7. Claims 1-16 are pending. Claims 1-16 are rejected. No claims are allowed. Contacts 8. Any inquiry concerning this communication or earlier communications from the examiner should be directed to Primary Examiner CAM N. NGUYEN whose telephone number is (571)272-1357. The examiner can normally be reached on M-F (9:30 am – 5:00 pm) at alternative worksite or at cam.nguyen@uspto.gov. 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 an application may be obtained from the Patent Application Information Retrieval (PAIR) system. Status information for published applications may be obtained from either Private PAIR or Public PAIR. Status information for unpublished applications is available through Private PAIR only. For more information about the PAIR system, see http://pair-direct.uspto.gov. Should you have questions on access to the Private PAIR system, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /Cam N. Nguyen/Primary Examiner, Art Unit 1736 /CNN/ November 01, 2025
Read full office action

Prosecution Timeline

Jun 01, 2023
Application Filed
Nov 01, 2025
Non-Final Rejection — §102, §112 (current)

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Prosecution Projections

1-2
Expected OA Rounds
85%
Grant Probability
97%
With Interview (+11.9%)
2y 8m
Median Time to Grant
Low
PTA Risk
Based on 1260 resolved cases by this examiner. Grant probability derived from career allow rate.

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