Prosecution Insights
Last updated: September 17, 2026
Application No. 17/442,581

A PROCESS AND APPARATUS FOR ACID MINE DRAINAGE TREATMENT

Final Rejection §103
Filed
Sep 23, 2021
Priority
Mar 25, 2019 — AU 2019900984 +1 more
Examiner
KEELING, ALEXANDER W
Art Unit
1795
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Engineroom Infrastructure Consulting Pty Ltd.
OA Round
4 (Final)
56%
Grant Probability
Moderate
5-6
OA Rounds
0m
Est. Remaining
94%
With Interview

Examiner Intelligence

Grants 56% of resolved cases
56%
Career Allowance Rate
332 granted / 594 resolved
-9.1% vs TC avg
Strong +38% interview lift
Without
With
+38.1%
Interview Lift
resolved cases with interview
Typical timeline
3y 4m
Avg Prosecution
39 currently pending
Career history
637
Total Applications
across all art units

Statute-Specific Performance

§101
1.1%
-38.9% vs TC avg
§103
55.9%
+15.9% vs TC avg
§102
16.7%
-23.3% vs TC avg
§112
21.6%
-18.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 594 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 . Response to Amendments This is a final office action in response to applicant's arguments and remarks filed on 06/18/2026. Status of Rejections All previous rejections are maintained. Claims 1-12, 15-17, and 19-22 are pending and under consideration for this Office Action. 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) 1-3, 8-11, 15-17, and 19-22 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rabaey et al (US 20110315561 A1) in view of James et al (US 20080169196 A1) and Jha et al (US 20160010222 A1). Claim 1: Rabaey discloses an apparatus for treatment of acid mine drainage (see e.g. abstract; [0054]), said apparatus comprising: at least one electrochemical reactor (see e.g. Fig 1) comprising at least one anode electrode (see e.g. #5 on Fig 1), at least one cathode electrode (see e.g. #4 on Fig 1) and a semipermeable membrane for separating the at least one anode electrode and the at least one cathode electrode and for defining an anode chamber containing the at least one anode electrode and a cathode chamber containing the at least one cathode electrode (see e.g. #6 on Fig 1; [0017]); at least one anolyte source containing buffer (see e.g. #7 on Fig 1; [0050]; [0056]) and at least one catholyte source containing the acid mine drainage (see e.g. #1 on Fig 1; [0054]), said at least one anolyte source and said at least one catholyte source being distinct from the at least one electrochemical reactor and in fluid communication with the at least one electrochemical reactor (see e.g. #1 and #7 on Fig 1); a first recirculation line configured to recirculate buffer to the cathode chamber (see e.g. #50 on Fig 4; [0093]) a second recirculation line configured to recirculate acid mine drainage to the cathode chamber (see e.g. #51 on Fig 4; [0093]); a power source for supplying an electrical current to the at least one electrochemical reactor (see e.g. [0081]), wherein supply of the electrical current is controlled so that the electrical current is supplied until a predetermined pH is reached (see e.g. [0005]: “Bioelectrochemical wastewater treatment can be accomplished by electrically coupling a microbial bioanode to a counter electrode (cathode) that performs a reduction reaction”; [0018]: “The anode and the cathode are connected to each other by an electrical circuit…a power supply may be included in the electrical circuit. This power supply can be used to apply a voltage on the system, which increases the rate of the electrochemical reactions taking place…This may result in a volumetric current density in the bioelectrochemical cell”; [0054]: “The cathode fluid may increase in pH by either electrochemical or bio-electrochemical reduction of electron acceptor”) for selective recovery of at least one of metals, critical elements, and water (see e.g. #45 and #46 on Fig 4; [0055]; [0092]), and wherein the selective recovery of the metals or critical elements includes precipitation of the metals or critical elements from the acid mine drainage and wherein a pH of the at least one catholyte reservoir is maintained at an elevated pH relative to untreated acid mine drainage (see e.g. [0055]: “the pH in the cathode is increased to a level where the metal ions precipitate from the fluid…The metal ions may precipitate after the cathode fluid has left the cathode compartment”) and wherein the precipitation is encouraged to occur within the at least one catholyte reservoir to resist precipitation or adherence of precipitant on a surface of the at least one cathode electrode (see e.g. #41 on Fig 4; [0055]: “precipitation may take place in a precipitation vessel”). Rabaey does not explicitly teach that the at least one anolyte source and the at least one catholyte source are each connected to a reservoir that is distinct from the reactor. However, Rabaey discloses that the anolyte and catholyte can individually be sent to storage (see e.g. [0039]; [0083]) and can also be recirculated (see e.g. [0093]). James teaches an apparatus (see e.g. abstract) for treatment of acid mine drainage (see e.g. [0004], [0029]), making it analogous art (see MPEP § 2141.01(a) I). The apparatus of James recirculates at least the catholyte into a reservoir (see e.g. [0011]) so that the apparatus can be run in a batch or flowthrough mode (see e.g. [0011]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey so that the second recirculate lane recirculates the catholyte between the cathode chamber and the at least one catholyte reservoir as taught in James to enable both batch or flowthrough processes. Furthermore, James teaches only using a single reservoir because the anolyte and catholyte are the same (see e.g. [0057]). However, it would have been obvious to a person having ordinary skill in the art before the effective filing date that a second reservoir can be included for the first recirculation line when the anolyte is different from the catholyte, such as taught in Rabaey. Furthermore, MPEP § 2144.04 VI B states “the court held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced”. Rabaey does not explicitly teach at least one sensor for monitoring a pH of a contents of the reactor. However, Rabaey teaches that the pH of a contents of the reactor is controlled and monitored (see e.g. [0055]; [0085]; [0109]). Therefore, a person having ordinary skill in the art before the effective filing date would be motivated to find a device sufficient to accomplish the monitoring of pH. Jha teaches an apparatus (see e.g. abstract) for treatment of acid mine drainage (see e.g. [0046]), making it analogous art (see MPEP § 2141.01(a) I). Jha teaches a pH sensor for monitoring a pH of a contents of the reactor (see e.g. [0065]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey to include the pH sensor of Jha as the device used to monitor the pH. Claim 2: Rabaey in view of James and Jha discloses that the buffer can be water (see e.g. Rabaey - [0056]) or an acidic buffer (acetic acid, see e.g. Rabaey - [0050]). It would have been obvious to a person having ordinary skill in the art before the effective filing date to select water or the acetic acid from the list of possible anolyte materials disclosed in Rabaey because KSR rationale E states that it is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Claim 3: Rabaey in view of James and Jha discloses that the buffer can be acetic acid (see e.g. Rabaey - [0050]). It would have been obvious to a person having ordinary skill in the art before the effective filing date to select the acetic acid from the list of possible anolyte materials disclosed in Rabaey because KSR rationale E states that it is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Claim 8: Rabaey in view of James and Jha discloses that the semipermeable membrane can be an anion exchange membrane (see e.g. Rabaey - [0017]). It would have been obvious to a person having ordinary skill in the art before the effective filing date to select an anion exchange membrane from the list of possible membranes disclosed in Rabaey because KSR rationale E states that it is obvious to choose “from a finite number of identified, predictable solutions, with a reasonable expectation of success” and MPEP § 2144.07 states “The selection of a known material based on its suitability for its intended use supported a prima facie obviousness determination in Sinclair & Carroll Co. v. Interchemical Corp., 325 U.S. 327, 65 USPQ 297 (1945)”. Claim 9: The limitation claiming that “the sulphuric acid is recovered from the buffer within the anode chamber of the reactor” is limiting an item in a list of alternatives in claim 1 and is contingent on the sulphuric acid being what is selectively recovered. Rabaey in view of James disclose selective recovery of at least one of metals, critical elements, and water (see e.g. Rabaey - #45 and #46 on Fig 4; [0055]; [0092]). Claim 9 does not narrow the claims to require the sulphuric acid is what is selectively recovered and thus does not limit claim 1 in the instances where a predetermined pH is reached for selective recovery of at least one of metals, critical elements, and water. Claim 10: Rabaey in view of James and Jha discloses that the water is recovered from the acid mine drainage in the cathode chamber of the reactor (see e.g. Rabaey – [0022]; [0092]). Claim 11: Rabaey in view of James and Jha discloses that the predetermined pH is dependent on the selected metals or critical elements to be recovered (See e.g. [0024]: “It will be appreciated that many wastewater streams contain dissolved cations and these dissolved cations are prone to precipitate if the pH of the wastewater stream increases, as many cations form carbonate and/or hydroxide precipitates if pH values increase above a threshold value. This value is somewhat dependent upon the composition of the liquid solution”) and wherein the predetermined pH includes “above 6.5” (see e.g. Rabaey - [0024]), “above 8 to 8.5” (see e.g. Rabaey - [0029]), and “in excess of 10” (see e.g. Rabaey - [0034]), which overlaps with the claimed range of “about 2 to about 10.2”. MPEP § 2144.04 states “In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990)”. Claim 15: Rabaey discloses a process for treatment of acid mine drainage (see e.g. abstract; [0054]), said process comprising: providing at least one electrochemical reactor (see e.g. Fig 1) comprising at least one anode electrode (see e.g. #5 on Fig 1), at least one cathode electrode (see e.g. #4 on Fig 1), and a semipermeable membrane for separating the at least one anode electrode and the at least one cathode electrode and for defining an anode chamber containing the at least one anode electrode and a cathode chamber containing the at least one cathode electrode (see e.g. #6 on Fig 1; [0017]); providing at least one anolyte source for containing buffer (see e.g. #7 on Fig 1; [0050]; [0056]) and at least one catholyte source containing the acid mine drainage (see e.g. #1 on Fig 1; [0054]), said at least one anolyte source and said at least one catholyte source being distinct from the at least one electrochemical reactor and in fluid communication with the anode chamber and the cathode chamber of the reactor, respectively (see e.g. #1 and #7 on Fig 1); supplying the acid mine drainage to the cathode chamber of the at least one electrochemical reactor from the at least one catholyte source (see e.g. #7 on Fig 1; [0050]; [0056]) and supplying the buffer to the anode chamber of the at least one electrochemical reactor from the at least one anolyte source (see e.g. #1 on Fig 1; [0054]); recirculating the buffer from the anode chamber (see e.g. #50 on Fig 4; [0093]); recirculating the acid mine drainage from the cathode chamber (see e.g. #51 on Fig 4; [0093]); controlling supply of an electrical current to the at least one electrochemical reactor (see e.g. [0081]) until a desired pH is reached (see e.g. [0005]: “Bioelectrochemical wastewater treatment can be accomplished by electrically coupling a microbial bioanode to a counter electrode (cathode) that performs a reduction reaction”; [0018]: “The anode and the cathode are connected to each other by an electrical circuit…a power supply may be included in the electrical circuit. This power supply can be used to apply a voltage on the system, which increases the rate of the electrochemical reactions taking place…This may result in a volumetric current density in the bioelectrochemical cell”; [0054]: “The cathode fluid may increase in pH by either electrochemical or bio-electrochemical reduction of electron acceptor”) for selective recovery of at least one of metals, critical elements, and water (see e.g. #45 and #46 on Fig 4; [0055]; [0092]), and wherein the selective recovery of the metals or the critical elements includes precipitating the metals or the critical elements from the acid mine drainage and the pH of the catholyte reservoir is controlled at an elevated pH relative to the acid mine drainage to encourage precipitation to occur within the at least one catholyte reservoir and to resist precipitation or adherence of precipitant on a surface of the at least one cathode electrode (see e.g. [0055]: “the pH in the cathode is increased to a level where the metal ions precipitate from the fluid…The metal ions may precipitate after the cathode fluid has left the cathode compartment”) and wherein the precipitation is encouraged to occur within the at least one catholyte reservoir to resist precipitation or adherence of precipitant on a surface of the at least one cathode electrode (see e.g. #41 on Fig 4; [0055]: “precipitation may take place in a precipitation vessel”). Rabaey does not explicitly teach that the at least one anolyte source and the at least one catholyte source are each connected to a reservoir that is distinct from the reactor. However, Rabaey discloses that the anolyte and catholyte can individually be sent to storage (see e.g. [0039]; [0083]) and can also be recirculated (see e.g. [0093]). James teaches an apparatus (see e.g. abstract) for treatment of acid mine drainage (see e.g. [0004], [0029]), making it analogous art (see MPEP § 2141.01(a) I). The apparatus of James recirculates at least the catholyte into a reservoir (see e.g. [0011]) so that the apparatus can be run in a batch or flowthrough mode (see e.g. [0011]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the method of Rabaey so that method recirculates the catholyte between the cathode chamber and the at least one catholyte reservoir as taught in James to enable both batch or flowthrough processes. Furthermore, James teaches only using a single reservoir because the anolyte and catholyte are the same (see e.g. [0057]). However, it would have been obvious to a person having ordinary skill in the art before the effective filing date that a second reservoir can be included for the anolyte recirculation line when the anolyte is different from the catholyte, such as taught in Rabaey. Furthermore, MPEP § 2144.04 VI B states “the court held that mere duplication of parts has no patentable significance unless a new and unexpected result is produced”. Rabaey does not explicitly teach monitoring a pH of contents of the at least one electrochemical reactor. However, Rabaey teaches that the pH of a contents of the reactor is controlled and known (see e.g. [0055]; [0085]; [0109]). Therefore, a person having ordinary skill in the art before the effective filing date would be motivated to find a way to know the pH in the reactor. Jha teaches an apparatus (see e.g. abstract) for treatment of acid mine drainage (see e.g. [0046]), making it analogous art (see MPEP § 2141.01(a) I). Jha teaches a pH sensor for monitoring a pH of a contents of the reactor (see e.g. [0065]). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the method of Rabaey to include monitoring a pH of contents of the at least one electrochemical reactor using the pH monitor of Jha. Claim 16: Rabaey in view of James and Jha discloses supplying the acid mine drainage includes pumping the acid mine drainage from the at least one catholyte reservoir to the cathode chamber (see e.g. Rabaey - [0107]). Claim 17: Rabaey in view of James and Jha discloses supplying the buffer includes pumping the buffer from the at least one anolyte reservoir to the anode chamber (see e.g. Rabaey - [0107]). Claim 19: Rabaey in view of James and Jha teaches that the process can be a batch process (see e.g. James - [0011]). Claim 20: Rabaey in view of James and Jha teaches that the process can be a continuous process (see e.g. James - [0011]). Claim 21: Rabaey in view of James and Jha teaches the controlling the electrical current supplied to the at least one electrochemical reactor includes applying the electrical current within a specified voltage (see e.g. [0018]) until a desired pH is reached (see e.g. [0005]: “Bioelectrochemical wastewater treatment can be accomplished by electrically coupling a microbial bioanode to a counter electrode (cathode) that performs a reduction reaction”; [0018]: “The anode and the cathode are connected to each other by an electrical circuit…a power supply may be included in the electrical circuit. This power supply can be used to apply a voltage on the system, which increases the rate of the electrochemical reactions taking place…This may result in a volumetric current density in the bioelectrochemical cell”; [0054]: “The cathode fluid may increase in pH by either electrochemical or bio-electrochemical reduction of electron acceptor”) for selective recovery of at least one of metals, critical elements, and water (see e.g. #45 and #46 on Fig 4; [0055]; [0092]). Claim 22: Rabaey in view of James and Jha teaches that the monitoring the pH includes using at least one sensor to monitor the pH (see e.g. Jha - [0065]). Claim(s) 4-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rabaey in view of James and Jha as applied to claim 1 above, and in further view of Fisher (US 20190382290 A1). Claim 4: Rabaey in view of James and Jha does not explicitly teach that the metals or critical elements recovered are at least one of aluminium, arsenic, barium, chromium, copper, iron, molybdenum, selenium, lead, cobalt, magnesium, manganese, molybdenum, nickel, zinc and cadmium. Rabaey discloses that the apparatus can treat mine drainage by precipitating metal ions out of the solution (see e.g. [0054]; [0055]) but does not specify what those metals are. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to precipitate known metals from mine drainage. Fisher teaches an apparatus (see e.g. abstract) for treatment of mine drainage (see e.g. [0147]), making it analogous art (see MPEP § 2141.01(a) I). Fisher teaches that arsenic, barium, chromium, copper, selenium, lead, cobalt, magnesium, manganese, nickel, zinc and cadmium can be recovered from these waste streams (see e.g. [0183]; [0185]; [0186]; [0188]; [0189]) to produce clean water (see e.g. abstract). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey so that the arsenic, barium, chromium, copper, selenium, lead, cobalt, magnesium, manganese, nickel, zinc and cadmium is precipitated out of the water to clean the water. Claim 5: Rabaey in view of James and Jha does not explicitly teach that the critical elements recovered include rare earth elements and yttrium (REY). Rabaey discloses that the apparatus can treat mine drainage by precipitating metal ions out of the solution (see e.g. [0054]; [0055]) but does not specify what those metals are. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to precipitate known metals from mine drainage. Fisher teaches an apparatus (see e.g. abstract) for treatment of mine drainage (see e.g. [0147]), making it analogous art (see MPEP § 2141.01(a) I). Fisher teaches that rare earth elements and yttrium (REY) can be recovered from these waste streams (see e.g. [0185]; [0190]) to produce clean water (see e.g. abstract). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey so that the rare earth elements and yttrium is precipitated out of the water to clean the water. Claim 6: Rabaey in view of James and Jha does not explicitly teach that the critical elements recovered include any one or more of cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, terbium, thulium and ytterbium or a hydroxide, oxide, (oxy)hydroxide or sulphate thereof. Rabaey discloses that the apparatus can treat mine drainage by precipitating metal ions out of the solution (see e.g. [0054]; [0055]) but does not specify what those metals are. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to precipitate known metals from mine drainage. Fisher teaches an apparatus (see e.g. abstract) for treatment of mine drainage (see e.g. [0147]), making it analogous art (see MPEP § 2141.01(a) I). Fisher teaches that cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, terbium, thulium and ytterbium can be recovered from these waste streams (see e.g. [0185]; [0190]) to produce clean water (see e.g. abstract). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey so that the cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanum, lutetium, neodymium, praseodymium, terbium, thulium and ytterbium is precipitated out of the water to clean the water. Claim 7: Rabaey in view of James, Jha, and Fisher teaches that the rare earth elements recovered includes scandium (see e.g. Fisher – [0190]). Claim(s) 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rabaey in view of James and Jha as applied to claim 1 above, and in further view of Morkovsky (US 5928493 A) Claim 12: Rabaey in view of James and Jha does not explicitly teach one or more additional electrochemical reactors arranged in series for sequential recovery of different metals and/or critical elements. Morkovsky teaches the use of multiple sequential reactors (see e.g. col 5, line 64-col 6, line 2) to extract useful metals (via precipitation) (see e.g. col 13 lines 12-18). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date to modify the apparatus of Rabaey to use the additional reactors disclosed by Morkovsky in order to more efficiently recover desired metals and critical elements from a stream of mixed metal-containing acid mine drainage. Response to Arguments Applicant's arguments filed 06/18/2026 have been fully considered but they are not persuasive. On page(s) 7-9, the Applicant argues that Rabaey is directed to a bioelectrochemical system which “is constrained by the tolerance limits of the microorganisms” and “In contrast, acid mine drainage (AMD) is highly variable and may exhibit strongly acidic conditions depending on the source and contaminant load”. “The claimed apparatus and process fundamentally differ from Rabaey in that they employ a non-biological electrochemical system driven by a conventional power source, without reliance upon microbial catalysis”. This argument is not considered persuasive. Claim 1 contains the transitional phrase “comprising” which “is inclusive or open-ended and does not exclude additional, unrecited elements or method steps” (see § MPEP 2111.03). Therefore, the presence of microorganisms in Rabaey does not disqualify it as prior art. Rabaey discloses an apparatus for treatment of acid mine drainage (see e.g. abstract; [0054]) and thus reads on the claim. Additionally, claim 1 does not contain any limitations regarding the value of the pH. The pH values in claim 11 overlap with pH ranges taught in Rabaey. On page(s) 9-10, the Applicant argues that “the recirculation [of Rabaey] is merely used as a mechanism for adjusting pH conditions within the bioelectrochemical system” and “There is no disclosure or suggestion that the recirculation arrangement is configured to intentionally promote precipitation in a physically separate reservoir external to the electrochemical reactor”. This is not considered persuasive. Rabaey explicitly discloses precipitating outside of the reactor in a precipitation vessel (see e.g. #41 on Fig 4; [0055]: “precipitation may take place in a precipitation vessel”). As the claim requires “at least one catholyte reservoir”, this means there can be multiple. In this case, the precipitation vessel can be considered a catholyte reservoir under the broadest reasonable interpretation whereas the other reservoir from the combination of Rabaey with James has the function of doing recirculation continuously or in batches. On page(s) 10, the Applicant argues that the instant invention has “significant technical advantages that are neither disclosed nor contemplated in Rabaey, including: preventing or substantially reducing precipitation within the electrochemical reactor itself; providing a dedicated external reservoir in which precipitation can be controlled and managed away from the electrode surfaces; reducing fouling, scaling, or adherence of precipitates on the cathode electrode, thereby maintaining electrochemical efficiency; and enabling continuous or prolonged operation of the electrochemical reactor while precipitate formation is managed externally”. However, these are all disclosed in Rabaey: preventing or substantially reducing precipitation within the electrochemical reactor itself (see e.g. [0055]); providing a dedicated external reservoir in which precipitation can be controlled and managed away from the electrode surfaces (see e.g. [0055]); reducing fouling, scaling, or adherence of precipitates on the cathode electrode, thereby maintaining electrochemical efficiency (see e.g. [0055]); and enabling continuous or prolonged operation of the electrochemical reactor while precipitate formation is managed externally (see e.g. #41 on Fig 4). On page(s) 11-12, the Applicant argues that “Rabaey's disclosure expressly teaches away from the pH elevation that is central to the claimed apparatus and process”. This is not considered persuasive. Rabaey explicitly discloses “the pH in the cathode is increased to a level where the metal ions precipitate from the fluid” (see e.g. [0055]). Furthermore, Rabaey explicitly discloses maintaining the pH within the range claimed in claim 11. On page(s) 12, the Applicant argues that Rabaey cannot be combined with James because “Rabaey is directed to a bioelectrochemical system, whereas James discloses a conventional electrochemical system… The operational constraints, design considerations, and process objectives of the two systems are materially different”. This is not considered persuasive. Both Rabaey and James teach apparatuses (see e.g. James - abstract) for treatment of acid mine drainage (see e.g. Rabaey - abstract; [0054]), James - [0004], [0029]), making them analogous art (see MPEP § 2141.01(a) I). Rabey already teaches recirculating the electrolyte (see e.g. #50 and #51 on Fig 4; [0093]). James teaches that adding a reservoir to a recirculation system allows the apparatus to be run in a batch or flowthrough mode (see e.g. [0011]). Therefore, the combination of Rabaey with James would be obvious to a person having ordinary skill in the art before the effective filing date of the instant invention with a reasonable expectation of success. On page(s) 13, the Applicant argues that it would not be obvious to use two different reservoirs in the combination of Rabaey with James because the catholyte reservoir recirculates the catholyte and precipitation. This is not considered persuasive. This is not considered persuasive. Rabaey already discloses a catholyte reservoir for precipitating (see e.g. [0055]). The claim requires at least one catholyte reservoir. The other reservoir in the combination was for recirculating the catholyte when batch processing is desired. On page(s) 14, the Applicant argues that “Jha's disclosure of pH sensors is generic in nature and cannot be used to bridge the structural and functional gaps between the applied prior art documents and the claimed apparatus and process”. This is not considered persuasive. Rabaey teaches that the pH of a contents of the reactor is controlled and monitored (see e.g. [0055]; [0085]; [0109]). Therefore, a person having ordinary skill in the art before the effective filing date would be motivated to find a device sufficient to accomplish the monitoring of pH. Jha provided a teaching for a pH sensor used with an apparatus (see e.g. abstract) for treatment of acid mine drainage (see e.g. [0046]). On page(s) 15, the Applicant argues that claim 9 was incorrectly interpreted. This is not considered persuasive. Claim 1 claims “the electrical current is supplied until a predetermined pH is reached for selective recovery of at least one of metals, critical elements, sulphuric acid and water”. Claim 9 does not require sulphuric acid to be what is recovered and claims that sulphuric acid, if recovered, is recovered from the buffer within the anode chamber. It is recommended to adjust the language to conform with the arguments being made. The rest of the arguments provide similar arguments to those addressed above. Conclusion THIS ACTION IS MADE FINAL. 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 ALEXANDER W KEELING whose telephone number is (571)272-9961. The examiner can normally be reached 7:30 AM - 4:00 PM. 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, Luan Van can be reached at 571-272-8521. 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. /ALEXANDER W KEELING/Primary Examiner, Art Unit 1795
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Prosecution Timeline

Show 1 earlier event
Feb 21, 2025
Non-Final Rejection mailed — §103
May 21, 2025
Response Filed
Oct 27, 2025
Final Rejection mailed — §103
Feb 27, 2026
Request for Continued Examination
Mar 05, 2026
Response after Non-Final Action
Apr 14, 2026
Non-Final Rejection mailed — §103
Jun 18, 2026
Response Filed
Jul 14, 2026
Final Rejection mailed — §103 (current)

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Patent 12735797
MODULAR SYSTEMS FOR HYDROGEN GENERATION AND METHODS OF OPERATING THEREOF
3y 4m to grant Granted Sep 15, 2026
Patent 12735794
BIOMIMETIC ELECTRODE AND MEMBRANELESS WATER ELECTROLYSIS REACTOR BASED ON ROSE PETAL EFFECT
2y 10m to grant Granted Sep 15, 2026
Patent 12729450
METHOD FOR OPTIMIZING CONSUMPTION OF THE OPERATING RESOURCES OF OZONE GENERATORS
3y 9m to grant Granted Sep 08, 2026
Patent 12729444
DEVICE FOR THE CATHODIC PROTECTION OF METAL COMPONENTS OF BOATS
2y 11m to grant Granted Sep 08, 2026
Patent 12697588
FLOW-ELECTRODE CARTRIDGE UNIT AND SUBMERGED FLOW-ELECTRODE CAPACITIVE DEIONIZATION DEVICE USING SAME
3y 8m to grant Granted Aug 04, 2026
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
56%
Grant Probability
94%
With Interview (+38.1%)
3y 4m (~0m remaining)
Median Time to Grant
High
PTA Risk
Based on 594 resolved cases by this examiner. Grant probability derived from career allowance rate.

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