Prosecution Insights
Last updated: April 17, 2026
Application No. 17/473,697

SYSTEM FOR COAL ASH CLEANUP

Final Rejection §103
Filed
Sep 13, 2021
Examiner
BASS, DIRK R
Art Unit
1779
Tech Center
1700 — Chemical & Materials Engineering
Assignee
unknown
OA Round
4 (Final)
62%
Grant Probability
Moderate
5-6
OA Rounds
3y 9m
To Grant
84%
With Interview

Examiner Intelligence

Grants 62% of resolved cases
62%
Career Allow Rate
515 granted / 831 resolved
-3.0% vs TC avg
Strong +22% interview lift
Without
With
+22.4%
Interview Lift
resolved cases with interview
Typical timeline
3y 9m
Avg Prosecution
32 currently pending
Career history
863
Total Applications
across all art units

Statute-Specific Performance

§101
0.3%
-39.7% vs TC avg
§103
48.6%
+8.6% vs TC avg
§102
29.0%
-11.0% vs TC avg
§112
15.9%
-24.1% vs TC avg
Black line = Tech Center average estimate • Based on career data from 831 resolved cases

Office Action

§103
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 Applicant’s response filed December 2, 2025 is acknowledged. Claims 10 and 14-16 are amended and claims 1-9 and 17-20 are withdrawn from consideration. Claims 10-16 are further considered on the merits. Response to Amendment In light of applicant’s amendment, the examiner modifies the grounds of rejection set forth in the office action filed July 2, 2025. Claim Rejections - 35 USC § 103 The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action. Claim(s) 10-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hodges et al., US 5656174 (Hodges) in view of Swearingen et al., US 2012/0296147 (Swearingen) and Henderson et al., US 10619324 (Henderson). Regarding claim 10, Hodges discloses a method for cleanup of settling pond slurries (abstract, figs. 1-3, C1/L17-23), wherein the slurry (REF 34) lies under a water level in the settling pond, the method consisting of: Providing a dewatering cell (REF 70, figs. 1, 3, see “tracking screen” and “collected and routed”, C7/L58-C8/L5) configured to receive a slurry, the dewatering cell disposed a distance from a settling pond; Lifting the slurry in the settling pond from beneath a water level (via REF 18, C4/L6-19); Receiving the slurry at a first point (REF 58, 66) outside the settling pond; Moving the slurry from the first point to a second point (REF 96, fig. 3A) disposed at the dewatering cell (REF 70); Depositing the slurry into the dewatering cell (via REF 100, figs. 1-3); Removing, while a solids content remains in the dewatering cell, a predetermined portion of the water from the slurry (via REF 70, figs. 1-3, C4/L66-C5/L17) and leaving a bed of dewatered product (REF 14, 92, fig. 2) in the dewatering cell; Removing the dewatered product from said dewatering cell using a bulk solids handler (see “conventional solids handling systems”, C3/L28-32); and Transporting the dewatered product from the dewatering cell to a predetermined delivery point outside the dewatering cell (C1/L20-21, C3/L28-32). Hodges does not disclose a method where the material being dredged and dewatered is coal ash. However, Swearingen discloses that coal ash is commonly deposited in sedimentation ponds for later treatment and separation (abstract, ¶ 0002, 0004). At the time of invention, it would have been obvious to one having ordinary skill in the art to modify the method of Hodges to process coal ash deposited in settling ponds as described in Swearingen since it has been shown that coal ash settling ponds require similar remediation techniques to minimize the environmental impact of deposited industrial waste streams. Hodges does not disclose driving a continuous miner, loader, or bulk solids handler on the surface of the dewatered product to remove said dewatered product from the dewatering cell. However, the use of heavy machinery such as a bulk solids handler driving on a surface to remove dewatered product is conventional and very well known in the art as seen in Henderson (C16/L14-22). At the time of invention, it would have been obvious to one having ordinary skill in the art to modify the method of Hodges to include the use of a bulk solids handler as described in Henderson since it has been shown that the use of such equipment is conventional and effective in transporting dewatered products from a treatment bed to downstream components and/or treatment. Regarding claim 11, modified Hodges discloses a method wherein receiving the coal ash at a first point (REF 58) outside the settling pond further consists of: Removing a first portion of the coal ash from the coal ash mixed with water (see “oversized scalping fraction 114”, fig. 2); Discharging the removed first portion of the coal ash into a secondary solids line (see fraction line incorporating REF 114, 118, 126, fig. 2); and Discharging the remainder of the coal ash mixed with water to the second point (see “undersized scalping fraction 110”, fig. 2). Regarding claim 12, modified Hodges discloses a method wherein removing a first portion of the coal ash from coal ash mixed with water further consists of: Removing the first portion of the coal ash from the coal ash mixed with water based on a predetermined size range of particles to be included in the first portion of the coal ash (C2/L15-39, C4/L46-65). Regarding claim 13, modified Hodges discloses a method wherein removing a first portion of the coal ash from coal ash mixed with water further consists of using at least one of a bulk material screener for rocks and debris (REF 58, see “scalping screen”, C4/L46-65). Regarding claims 14-15, Swearingen further discloses providing a dewatering cell having a water retaining structure at a site, said water retaining structure formed of a concrete sump (see “concrete sump”, ¶ 0066). Regarding claim 16, modified Hodges discloses a method further consisting of returning a portion of water removed from the coal ash mixed with water at the dewatering cell back to the original settling pond (C8/L38-39). Response to Arguments Applicant's arguments filed December 2, 2025 have been fully considered and are persuasive. Accordingly, the 35 U.S.C. 112 rejections have been withdrawn. However, rejections provided in the office action filed March 17, 2025 are sustained in light of the use of “consisting of” language due to the open-ended nature of claim language drawn to “a first point” and “a second point”. Applicant’s disclosure notes the first point can be a solids separation system which further utilizes flocculants to agglomerate solids for easier downstream separations. Therefore, the examiner maintains the combination of prior art discloses these elements as seen in the rejections above. Conclusion Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to DIRK R BASS whose telephone number is (571)270-7370. The examiner can normally be reached 8-4:30 EST Monday-Friday. 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, Bobby Ramdhanie can be reached on (571) 270-3240. 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. DIRK R. BASS Primary Examiner Art Unit 1779 /DIRK R BASS/Primary Examiner, Art Unit 1779
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Prosecution Timeline

Sep 13, 2021
Application Filed
Aug 13, 2024
Non-Final Rejection — §103
Jan 16, 2025
Response Filed
Mar 11, 2025
Final Rejection — §103
Jun 16, 2025
Response after Non-Final Action
Jun 26, 2025
Request for Continued Examination
Jun 28, 2025
Response after Non-Final Action
Jun 30, 2025
Non-Final Rejection — §103
Dec 02, 2025
Response Filed
Feb 26, 2026
Final Rejection — §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

5-6
Expected OA Rounds
62%
Grant Probability
84%
With Interview (+22.4%)
3y 9m
Median Time to Grant
High
PTA Risk
Based on 831 resolved cases by this examiner. Grant probability derived from career allow rate.

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