Prosecution Insights
Last updated: April 19, 2026
Application No. 18/233,949

Geothermally Powered Pyrometallurgical Zinc Production

Non-Final OA §103
Filed
Aug 15, 2023
Examiner
KESSLER, CHRISTOPHER S
Art Unit
1759
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Enhancedgeo Holdings LLC
OA Round
1 (Non-Final)
59%
Grant Probability
Moderate
1-2
OA Rounds
3y 10m
To Grant
74%
With Interview

Examiner Intelligence

Grants 59% of resolved cases
59%
Career Allow Rate
465 granted / 783 resolved
-5.6% vs TC avg
Moderate +15% lift
Without
With
+15.0%
Interview Lift
resolved cases with interview
Typical timeline
3y 10m
Avg Prosecution
61 currently pending
Career history
844
Total Applications
across all art units

Statute-Specific Performance

§101
1.2%
-38.8% vs TC avg
§103
45.2%
+5.2% vs TC avg
§102
16.2%
-23.8% vs TC avg
§112
27.4%
-12.6% vs TC avg
Black line = Tech Center average estimate • Based on career data from 783 resolved cases

Office Action

§103
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 . Election/Restrictions Applicant's election with traverse of group I, claims 1-7 in the reply filed on 1 December 2025 is acknowledged. The traversal is on the ground(s) that the apparatus as claimed cannot be used to practice another and materially different process, because the material of zinc is claimed in the apparatus claims. This is not found persuasive because applicant’s arguments are not commensurate in scope with what is claimed. A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." In re Otto, 312 F.2d 937, 136 USPQ 458, 459 (CCPA 1963); see also In re Young, 75 F.2d 996, 25 USPQ 69 (CCPA 1935). In this case the limitation of being “configured to” process zinc materials would not limit the skilled artisan to using only what is enumerated, nor limit them from using the apparatus to practice refining of different materials such as tin. The requirement is still deemed proper and is therefore made FINAL. Drawings The drawings were received on 15 August 2023. These drawings are accepted. 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. Claim(s) 1-4 and 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20060123952 A1 (hereinafter “Wilson”), in view of US 20130333383 A1 (hereinafter “Schwark”). Regarding claim 1, A claim is only limited by positively recited elements. Thus, "[i]nclusion of the material or article worked upon by a structure being claimed does not impart patentability to the claims." In re Otto, 312 F.2d 937, 136 USPQ 458, 459 (CCPA 1963); see also In re Young, 75 F.2d 996, 25 USPQ 69 (CCPA 1935). In this case the limitations of being configured to handle the work at various stages are considered inasmuch as they impart structure into the system being claimed. Wilson teaches a process and apparatus for processing zinc. Wilson teaches that zinc oxide material is formed to a pellet (see [0020]-[0027]). Wilson teaches the material is heated, reduced, and vaporized (see [0028]-[0033]). The apparatus (system) of Wilson is best shown in Fig 2 and [0082]-[0095]). Wilson teaches a furnace retort with first chamber 154 ([0082]-[0085] and Fig 2). Wilson teaches that the chamber includes combustion zones 154a and 154b (see [0085]-[0088] and Fig. 2). Wilson teaches that in a first zone the temperature of a pellet is raised, which releases organic material, and in the second combustion zone, a reduction of metal oxides to metal is effected (see [0086]-[0087]). Thus Wilson teaches a sinter (first combustion zone 154a) which raises the temperature and removes organics, and a retort furnace (150, 154b) configured to receive the product from the sinter. Wilson teaches that the first combustion zone receives gases (See [0085] and Fig 2). Thus the sinter is configured to receive the combustion gases and zinc oxide and heat them. Wilson teaches that the second combustion zone is configured to receive the heated pellets (and remaining organics) and to heat them and reduce them ([0087]-[0088]). Thus the retort is configured to receive coke and sinter and combustion gases and reduce. Wilson teaches that a condenser 124 is in communication with the second zone 154b (see Fig 2 and [0088]-[0089]). Wilson teaches that the condenser is designed to recover the cooling zinc vapor to form liquid zinc (see [0036] or [0048]-[0049]). Wilson teaches that the molten droplets may be sent to the waste gas coming out ([0048]-[0049]). Thus the condenser is configured to receive cooling fluid and transfer the heat from zinc vapor to the fluid. Wilson teaches a collecting trough adjacent the condenser in Fig 2 (not labeled). The trough inherently includes the feature of being able to cast the liquid to a solid as by cooling. Wilson does not teach a geothermal system with wellbore extending to an underground magma reservoir, and heating heat transfer fluid to form heated heat transfer fluid. Wilson does not teach that the heated heat transfer fluid is used to heat the zinc oxide in the sinter. Wilson does not teach that the heated heat transfer fluid is used to heat the product sinter in the retort. Wilson teaches that combustion burners are implemented (see [0085] and Fig 2). Wilson does teach that it is desirable to preheat air admitted into portions of the apparatus as by heat exchange with waste gases (See [0054] and [0089]-[0091]). Schwark teaches a heat exchange system for harnessing subterranean heat energy (see title, abstract). Schwark teaches that a well is used, down which a working fluid is sent (see SUMMARY OF THE INVENTION). Schwark teaches that the heated fluid then powers turbines or other processes (see SUMMARY). Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]). Schwark teaches that the heat from the heated fluid may be used for industrial heating or direct heating (see [0099]-[0100]). Schwark teaches that the direct heating includes preheating for an industrial process (see [0100]). Schwark teaches that the system may include a plurality of wellbores into a subterranean zone (see [0114]-[0118]). Schwark teaches subterranean zone may include magma (see [0114]-[0118]). Schwark teaches that fluids such as methanol or water may be used ([0118]). It would have been obvious to one of ordinary kill in the art at time of filing to have altered the system of Wilson as by using the heat exchanger system of Schwark for preheating the retort of Wilson, including the two zones, because Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]) and may be used for preheating for industrial processes (see [0100]). Regarding claim 2, Wilson teaches that the retort includes an inlet tube that feeds the pellets into tubes for moving through the furnace (see Fig 2 and [0082]-[0085]). The system thus defines a “conveyor” that transports the material. Wilson teaches that it is desirable to preheat air admitted into portions of the apparatus as by heat exchange with waste gases (See [0054] and [0089]-[0091]). Schwark teaches a heat exchange system for harnessing subterranean heat energy (see title, abstract). It would have been obvious to one of ordinary skill in the art at time of filing to have altered the system of Wilson as by using the heat exchanger system of Schwark for preheating the retort of Wilson, including the two zones, because Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]) and may be used for preheating for industrial processes (see [0100]). Wilson teaches that the system includes an induction heater, having a slag outlet and also a molten lead outlet [0091]-[0094] and Fig 2.) Regarding claim 3, Wilson teaches that it is desirable to preheat air admitted into portions of the apparatus as by heat exchange with waste gases (See [0054] and [0089]-[0091]). Schwark teaches a heat exchange system for harnessing subterranean heat energy (see title, abstract). It would have been obvious to one of ordinary skill in the art at time of filing to have altered the system of Wilson as by using the heat exchanger system of Schwark for preheating the retort of Wilson, including the two zones, because Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]) and may be used for preheating for industrial processes (see [0100]). Wilson teaches that the system includes an induction heater, having a slag outlet and also a molten lead outlet [0091]-[0094] and Fig 2.) Regarding claim 4, Wilson teaches that a condenser 124 is in communication with the second zone 154b (see Fig 2 and [0088]-[0089]). Wilson teaches that the condenser is designed to recover the cooling zinc vapor to form liquid zinc (see [0036] or [0048]-[0049]). Wilson teaches that the molten droplets may be sent to the waste gas coming out ([0048]-[0049]). Thus the condenser is configured to receive cooling fluid through the tubes (Fig 2) and transfer the heat from zinc vapor to the fluid. Regarding claim 6, Schwark teaches a heat exchange system for harnessing subterranean heat energy (see title, abstract). Schwark teaches that the heated fluid then powers turbines (i.e., motors) or other processes (see SUMMARY). It would have been an obvious matter to the skilled artisan to have used the turbines disclosed to generate the power needed to run the machinery. Regarding claim 7, Regarding claim 3, Wilson teaches that it is desirable to preheat air admitted into portions of the apparatus as by heat exchange with waste gases (See [0054] and [0089]-[0091]). Schwark teaches a heat exchange system for harnessing subterranean heat energy (see title, abstract). It would have been obvious to one of ordinary skill in the art at time of filing to have altered the system of Wilson as by using the heat exchanger system of Schwark for preheating the retort of Wilson, including the two zones, because Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]) and may be used for preheating for industrial processes (see [0100]). Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over US 20060123952 A1 (hereinafter “Wilson”), in view of US 20130333383 A1 (hereinafter “Schwark”) as applied to claim 1 above, and further in view of US 4511461 A (hereinafter “Kruyer”). Wilson in view of Schwark does not teach wherein the system includes an ore crusher and a flotation tank as claimed. Wilson teaches that the pellets are from EAF fines (see [0001]). Kruyer teaches a process for recovering minerals (see title). Kruyer teaches that an ore is directed to a crusher then sent to a slurrying tank (see col 6-7, Fig 2-3 and Example 1). Kruye rteaches that the ore slurry thus obtained may be roasted (see col 26), reading on a roaster. Kruyer teaches that the process is suitable for processing sphalerite ore (See cols 10-11), and thus the equipment is configured to receive sphalerite ore. Kruyer teaches that the process allows for large quantities or ore to be processed with few steps (See OBJECTS OF THE INVENTION). It would have been obvious to one of ordinary skill in the art at time of filing to have altered the system of Wilson as by using the heat exchanger system of Schwark for preheating the retort of Wilson, including the two zones, because Schwark teaches that the invention is efficient and cost-effective (see [0007]-[0013]) and may be used for preheating for industrial processes (see [0100]), and further to have used the equipment of Kruyer as by processing of ore along with the improved geothermal processing, because Kruyer teaches that the process allows for large quantities or ore to be processed with few steps (See OBJECTS OF THE INVENTION). Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER S KESSLER whose telephone number is (571)272-6510. The examiner can normally be reached 9-5:30. 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, Curt Mayes can be reached at 571-272-1234. 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. CHRISTOPHER S. KESSLER Primary Examiner Art Unit 1734 /CHRISTOPHER S KESSLER/ Examiner, Art Unit 1759
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Prosecution Timeline

Aug 15, 2023
Application Filed
Jan 10, 2026
Non-Final Rejection — §103 (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
59%
Grant Probability
74%
With Interview (+15.0%)
3y 10m
Median Time to Grant
Low
PTA Risk
Based on 783 resolved cases by this examiner. Grant probability derived from career allow rate.

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