Prosecution Insights
Last updated: April 19, 2026
Application No. 18/376,286

METHOD AND COMPOSITION FOR TREATING TAILINGS

Non-Final OA §103§112§DP
Filed
Oct 03, 2023
Examiner
CAI, WENWEN
Art Unit
1763
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Sterling Specialty Chemicals Holding UK Limited
OA Round
1 (Non-Final)
60%
Grant Probability
Moderate
1-2
OA Rounds
3y 2m
To Grant
80%
With Interview

Examiner Intelligence

Grants 60% of resolved cases
60%
Career Allow Rate
509 granted / 850 resolved
-5.1% vs TC avg
Strong +20% interview lift
Without
With
+19.8%
Interview Lift
resolved cases with interview
Typical timeline
3y 2m
Avg Prosecution
74 currently pending
Career history
924
Total Applications
across all art units

Statute-Specific Performance

§101
0.8%
-39.2% vs TC avg
§103
43.6%
+3.6% vs TC avg
§102
17.4%
-22.6% vs TC avg
§112
27.9%
-12.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 850 resolved cases

Office Action

§103 §112 §DP
DETAILED ACTION The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . Claim Objections Claim 20 objected to because of the following informalities: the claim is suggested to rephrased to, such as a method for separating bitumen from mineral solids by treating tailings, or a method for treating tailings to separate bitumen from mineral solids. Claim 20 objected to because of the following informalities: the claim is suggested to read as: forming flocs comprising solid particulate material, and separating the formed flocs from the aqueous phase. Claim 25-26, 29 objected to because of the following informalities: floes should be flocs, the unit of the particle diameter should be um. Appropriate correction is required. Claim Rejections - 35 USC § 112 The following is a quotation of 35 U.S.C. 112(a): (a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention. The following is a quotation of 35 U.S.C. 112 (pre-AIA ), first paragraph: The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same and shall set forth the best mode contemplated by the inventor of carrying out his invention. Claims 30-33 rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention. For claim 30, the specification does not support “a heterocyclic amine”. For claim 30-31, the specification does not support “the ionic liquid comprises a heterocyclic amine”. Instead, the specification discloses the ionic liquid is prepared from… For claim 33, the specification does not support the fatty acid comprises rosin acid. 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 32-33 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 pre-AIA the applicant regards as the invention. For claim 33, rosin acid is not a species of fatty acid. Clarification is required. For claim 32, amidine and guanidine are not species of heterocyclic amine. Clarification is required. 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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. Claims 20-30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Duttlinger JR et al (US 2014/0054232) in view of Painter et al (US 2012/0048783). Claims 20-22, 30: Duttlinger teaches a method for treating tailings to recover bitumen from mineral solids, the method comprising adding polyacrylamide to the tailings, forming flocs and separating bitumen from particulate material [0003-0005]. The solid level of the tailings is less than 20wt%. The polyacrylamide can be either cationic or anionic. Duttlinger does not teach the use of ionic liquid in the process. However, Painter discloses a similar process and teaches using an ionic liquid, such as 1-butyl-2,3-dimethyl-imidazolium, to assist in recovery of bitumen [0009, 0044]. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to add ionic liquid in the separation process of Duttlinger because both compositions are known for increasing the recovery of bitumen from tailings. "It is prima facie obvious to combine two compositions each of which is taught by the prior art to be useful for the same purpose, in order to form a third composition to be used for the very same purpose.... [T]he idea of combining them flows logically from their having been individually taught in the prior art." In re Kerkhoven, 626 F.2d 846, 850, 205 USPQ 1069, 1072 (CCPA 1980). Duttlinger is silent with respect to the dosage feature of the method. However, the combination of teachings from Painter and Duttlinger have rendered obvious the instantly claimed ingredients, amounts and process thereof. Therefore, it is reasonable that one of ordinary skill in the art would expect the claimed feature to naturally arise. Alternatively, Duttlinger and Painter teach both ionic liquid and polyacrylamide can flocculate mineral particles and therefore using ionic liquid additionally can reduce, partially replace or even fully replace the need of polyacrylamide to achieve the same solid reduction. Claims 23-24: Duttlinger teaches the amount of polyacrylamide can be 0.1kg/ton (100g/ton). Additionally, it would have been obvious to one of ordinary skill in the art at the time the invention was made to adjust the contents of polyacrylamide and ionic liquid depending on the mineral content and bitumen content in the tailings through routine experimentation, because they are result effective variables wherein too small amount would decrease the separation efficiency, too high amount would cause waste of the flocculating agent and potential gelling of polyacrylamide. Case law holds that "discovery of an optimum value of a result effective variable in a known process is ordinarily within the skill of the art." In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980). Claims 25-26: the content of fine particles in the aqueous phase after separation and the content of solid content in the settled floc phase depend on the original contents in the tailings and the amount of flocculating agent used. Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Claim 27: Painter teaches recovery and recycle of the aqueous phase [0053-0056]. Claim 28: Case law holds that selection of any order of performing process steps or mixing ingredients is prima facie obvious in the absence of new or unexpected results; In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930), In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946). Claim 29: Painter teaches the formed floces can be filtered from the liquid phase [0054-0056]. Allowable Subject Matter Claims 31-33 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(a) and 35 U.S.C. 112 (b), 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: Duttlinger and Painter do not teach or fairly suggest the ionic liquid comprises a heterocyclic amine and a fatty acid. In light of the above discussion, it is evident as to why the present claims are patentable over the prior art. 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 claims at issue 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); and 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 a nonstatutory double patenting ground provided the reference application or patent either is shown to be commonly owned with this application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b). The USPTO internet Web site contains terminal disclaimer forms which may be used. Please visit http://www.uspto.gov/forms/. The filing date of the application will determine what form 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 http://www.uspto.gov/patents/process/file/efs/guidance/eTD-info-I.jsp. Claims 1-33 rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-12 of U.S. Patent No.11,001,761. Although the claims at issue are not identical, they are not patentably distinct from each other because ‘761 claims a method for separating bitumen from mineral solids by treating tailings, because both ionic liquid and polyacrylamide can flocculate mineral particles and therefore using ionic liquid additionally can reduce, partially replace or even fully replace the need of polyacrylamide to achieve the same solid reduction compared to a process using only polyacrylamide. Any inquiry concerning this communication or earlier communications from the examiner should be directed to WENWEN CAI whose telephone number is (571)270-3590. The examiner can normally be reached M-F 9am-6pm. 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, Joseph Del Sole can be reached at (571)272-1130. 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. /WENWEN CAI/Primary Examiner, Art Unit 1763
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Prosecution Timeline

Oct 03, 2023
Application Filed
Mar 09, 2026
Non-Final Rejection — §103, §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
60%
Grant Probability
80%
With Interview (+19.8%)
3y 2m
Median Time to Grant
Low
PTA Risk
Based on 850 resolved cases by this examiner. Grant probability derived from career allow rate.

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