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
11/12/2025.
Status of Rejections
All previous rejections are maintained.
Claims 1-5, 8-15, 20-31, 33, and 36 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) 1-5, 8-15, 22-24, 27-31, 33, and 36 is/are rejected under 35 U.S.C. 103 as being unpatentable over Scott in view of Oze, Moran, Zhao, and Thorsen, as evidenced by Minnesota for claims 13 and 15.
Scott et al (US 20230060147 A1).
Oze et al (“Transformation of abundant magnesium silicate minerals for enhanced CO2 sequestration”, Communications Earth & Environment, Feb 2021, 2, 25, pages 1-6).
Moran et al (US 6132590 A).
Zhao et al (“Preparation of magnesium hydroxide from serpentinite by sulfuric acid leaching for CO2 mineral carbonation”, Minerals Engineering, Volume 79, August 2015, Pages 116-124).
Thorsen et al (WO 0029327 A1).
“Pyroxene” (University of Minnesota, 2023, referred to as Minnesota herein).
Claim 1: Scott discloses method of preparing a metal hydroxide (see e.g. abstract), the method comprising:
subjecting a mixture comprising a solvent (see e.g. [0114]) and a solid substrate (silicate, see e.g. [0101]) to a stimulus (acid, see e.g. [0113]) in order to leach a metal cation from the solid substrate into the solvent (“digest”, see e.g. [0193]), thereby forming a solution comprising the metal cation in the solvent (see e.g. [0193]);
contacting the solution with a cathode thereby electrolytically precipitating the metal hydroxide from the concentrated solution (see e.g. [0134] and [0139]); and wherein:
the metal cation is Mg(II) (see e.g. [0134]).
Scott discloses that the method is carried out at a temperature of less than 120oC, which overlaps with the claimed range of about 20 °C to about 40 °C. MPEP § 2144.05 I 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)”.
During the interview conducted on 07/11/2025, the Applicant argued that although Scott teaches a range that might encompass the claimed range, it would not be obvious to select the claimed temperatures that are much lower than the 120 oC explicitly disclosed in Scott. In the interest of compact prosecution, further art is being provided to show that this is not the case. Oze, which shares authors with the Scott reference, teaches a substantially similar process to that of Scott (see e.g. Fig 1 of Scott and Fig 1 of Oze), wherein the specified temperature for the processing steps for forming Mg(OH)2 is 20o C (see e.g. page 2, col 2, paragraph starting with “Methods: synthesis). Similarly, Moran teaches a process of producing metal hydroxides (see e.g. col 4, lines 30-32) via electrolysis (see e.g. abstract) wherein the temperature can be as low as 20o C and up to 100 oC. Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Scott by adjusting and selecting a temperature between 20 oC and 120 oC as shown in the prior art to get the desired reaction conditions.
Scott does not explicitly teach that the stimulus is a first stimulus of sonication. Scott discloses that the substrate can be serpentine (see e.g. [0101]). Zhao teaches that the addition of ultrasonication can help improve the digestion of serpentine/leaching of magnesium from serpentine (see e.g. page 121, col 1, paragraph starting with “A set of batch” and page 123, col 2, paragraph “4. Conclusion”). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Scott by having the stimulus include sonication as taught in Zhao to further enhance the leaching step.
Scott does not explicitly teach a step of concentrating the solution comprising the metal cation by contacting the solution with a nanofiltration membrane, thereby forming a concentrated solution of concentration metal cations; wherein the nanofiltration membrane selectively filters multivalent ions and allows monovalent ions to pass through.
However, Scott does disclose treating the solution by subjecting it to filtration to remove byproducts, especially after the addition of NaOH (see e.g. [0126], [0127], [0165], [0194]) as well as utilizing means to increase the concentration Mg (see e.g. [0191]). Thorsen teaches a method of treating a solution containing Mg2+ and Na+ ions (see e.g. page 2, lines 11-14), wherein the magnesium can be concentrated and the sodium is removed (see e.g. page 1, lines 21-22) via a nanofiltration membrane (see e.g. page 2, lines 11-14). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Scott by including step of concentrating the solution comprising the metal cation by contacting the solution with a nanofiltration membrane, thereby forming a concentrated solution of concentration metal cations; wherein the nanofiltration membrane selectively filters multivalent ions and allows monovalent ions to pass through as taught in Thorsen to remove the unneeded sodium from the from the solution and further concentrate the magnesium to be reacted in the electrolysis step.
Claim 2: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the method further comprises subjecting the mixture comprising a solvent and a solid substrate to a second stimulus and the second stimulus is an acid (see e.g. [0113] of Scott)
Claim 3: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the acid comprises hydrochloric acid, nitric acid, acetic acid, citric acid, or a combination thereof (see e.g. [0110] of Scott).
Claim 4: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the solvent has a pH of less than 6 (see e.g. [0108] of Scott)
Claim 5: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that has a pH ranging from -1 to 4 (see e.g. [0108] of Scott), overlapping with the claimed rang of 0 to about 3. MPEP § 2144.05 I 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 8: Scott in view of Oze, Moran, Zhao, and Thorsen teaches that the sonication is applied via a probe (see e.g. page 118, Fig 3 of Zhao).
Claim 9: Scott in view of Oze, Moran, Zhao, and Thorsen teaches that the sonication is applied at a frequency range of 40 kHz (see e.g. page 121, col 1, paragraph starting with “Some lump experiments” of Zhao), falling within the claimed range of about 2 Hz to about 2 MHz.
Claim 10: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the solvent is water (see e.g. [0114] of Scott).
Claim 11: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the solvent comprises a salt (see e.g. [0130] of Scott).
Claim 12: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the salt comprises a chloride or a sulfate (see e.g. [0130] of Scott).
Claim 13: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the metal cation can also include Ca(II) (Scott discloses that silicate source can be pyroxene, which as evidenced by Minnesota, contains both Mg and Ca).
Claim 14: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the metal cation is Mg(II) (see e.g. abstract of Scott).
Claim 15: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the metal cation is a mixture of Ca(II) and Mg(II) (Scott discloses that silicate source can be pyroxene, which as evidenced by Minnesota, contains both Mg and Ca).
Claim 22: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the cathode comprises an electroactive surface (see e.g. [0137] of Scott).
Claim 23: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the electroactive active surface comprises a metallic composition or a non-metallic composition (see e.g. [0137] of Scott).
Claim 24: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the electroactive surface comprises titanium oxide (see e.g. [0137] of Scott).
Claim 27: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the cathode is a rotating disc cathode (see e.g. [0138] of Scott).
Claim 28: Scott in view of Oze, Moran, Zhao, and Thorsen discloses removing the one or more hydroxide solids from the surface of cathode (see e.g. [0138]-[0139] of Scott).
Claim 29: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the removing the one or more hydroxide solids from the surface of the cathode comprises scraping the surface of the cathode (see e.g. [0138] of Scott).
Claim 30: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that removing the one or more hydroxide solids from the surface of the cathode comprises rotating the rotating disc cathode past a scraper (see e.g. [0138] of Scott).
Claim 31: Scott in view of Oze, Moran, Zhao, and Thorsen does not disclose pressuring the system during the method, and thus it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the method of Scott would be carried out at about ambient pressure.
Claim 33: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that the solution comprising the metal cation further comprises Cl- (see e.g. [0130] of Scott).
Claim 36: Scott in view of Oze, Moran, Zhao, and Thorsen discloses that removing the one or more hydroxide solids from the surface of the cathode is performed via mechanical abrasion (scraping, see e.g. [0138] of Scott).
Claim(s) 20 and 21 is/are rejected under 35 U.S.C. 103 as being unpatentable over as Scott in view of Oze, Moran, Zhao, and Thorsen as applied to claim 1 above, and in further view of Apoza (“Ferro-nickel slag”, 2020).
Claim 20: Scott in view of Oze, Moran, Zhao, and Thorsen does not explicitly teach that the solid substrate comprises industrial waste, alkaline rock, or a combination thereof. Scott discloses that the substrate should be a source of magnesium silicate (see e.g. [0101]) with iron byproducts (see e.g. [0182]). Apoza teaches that ferro-nickel slag comprises magnesium silicate (see e.g. page 1). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Scott to use ferro-nickel slag as taught in Apoza because Apoza satisfies the requirements for the magnesium source in Scott.
Claim 21: Scott in view of Oze, Moran, Zhao, Thorsen, and Apoza teaches that the industrial waste comprises slag (see e.g. page 1 Apoza).
Claim(s) 25 is/are rejected under 35 U.S.C. 103 as being unpatentable over as Scott in view of Oze, Moran, Zhao, and Thorsen as applied to claim 1 above, and in further view of Dinamani et al (“Electrosynthesis of Mg(OH)2 Coatings on Stainless Steel Substrates”, Journal of Applied Electrochemistry, 34, 899–902, 2004).
Claim 25: Scott in view of Oze, Moran, Zhao, and Thorsen does not explicitly teach that the electroactive surface comprises stainless steel. Dinamani teaches that stainless steel is a suitable cathode material for the electrolytic deposition of magnesium hydroxide (see e.g. abstract). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the instant invention to modify the method of Scott to use stainless steel as the cathode material because Dinamani teaches that stainless steel is a suitable cathode material for the electrolytic deposition of magnesium hydroxide 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(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over as Scott in view of Oze, Moran, Zhao, and Thorsen as applied to claim 1 above, and in further view of Gilliam et al (US 20130034489 A1).
Claim 26: Scott in view of Oze, Moran, Zhao, and Thorsen does not explicitly teach that the electroactive surface comprises an electroactive mesh comprising pores having a diameter in the range of about 0.1 nm to about 10000 µm. Gilliam discloses a system for electrolytically forming metal hydroxides (see e.g. abstract) wherein the cathode is a fine mesh stainless steel cathode (see e.g. [0038]). Gilliam further teaches that the cathode mesh (same as electroactive mesh) comprises pores having a diameter of about 3 mm (see e.g. [0037]) which falls within the claimed range of about 0.1 nm to about 10000 um. It would have been obvious to a person having ordinary skill in the art before effective filing date of the instant invention to modify the method taught by Scott in view of Oze, Moran, Zhao, and Thorsen by using a fine mesh stainless steel cathode having pore size about 3 mm as taught by Gilliam because Gilliam teaches this is a suitable cathode for forming metal hydroxides electrolytically 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)”.
Response to Arguments
Applicant's arguments filed 11/12/2025 have been fully considered but they are not persuasive.
On page(s) 3, the Applicant argues that ‘[O]nly by applying impermissible hindsight based upon the disclosure in the present specification can one cherrypick which parts of the cited combination of references to heed, and which parts to ignore, in order to arrive at the pending claims’. This is not considered persuasive. The art combination relied on the teachings from the references to give motivation for combining Scott with Thorsen. According to KSR rationale G ‘Some teaching, suggestion, or motivation in the prior art that would have led one of ordinary skill to modify the prior art reference or to combine prior art reference teachings to arrive at the claimed invention’ is a suitable rational for the conclusion of obviousness (see MPEP § 2141 III).
On page(s) 3-4, the Applicant argues that ‘Thorsen provides no framework as to how said process or any step in said process might be incorporated into a process which implements markedly different chemical principles. For example, since Thorsen is purely a filtration process, it is unclear where, how, or at which point a filtration process would be incorporated into the system/process of Scott, which includes leaching steps, electrolysis steps, silica and iron recovery steps, etc.’. This is not considered persuasive. As established in the prior art rejection, Scott teaches using numerous filtration steps (see e.g. [0126], [0127], [0165], [0194]) and the desire to concentrate Mg (see e.g. [0191]). Scott also teaches that sodium ions are introduced into the system (see e.g. [0128]), which would reduce the purity of the magnesium stream. Thus, it would be clear to a person having ordinary skill in the art before the effective filing date that the nanofiltration step would occur when after the sodium has been added to create a purified Mg product stream based on the disclosure of Scott.
On page(s) 3-4, the Applicant argues that ‘Thorsen describes a stand-alone, multi-stage filtration process, with no prior or subsequent reaction steps. Thorsen does not provide any guidance on how the components or steps therein may be split or appropriated to add a multivalent ion nanofiltration concentration step within another chemical process. …The nanofiltration steps of Thorsen are interdependent…Thus, nanofiltration in Thorsen is not disclosed as a unit or step that can merely be incorporated into another process or system. One of ordinary skill in the art would recognize that Thorsen’s concentration of MgCl2 using nanofiltration is dependent on the composition of the feed solution and the staged design of the process. Merely importing a nanofiltration step from the process of Thorsen into that of Scott does not guarantee the same results’. This is not considered persuasive. The Applicant argues that the nanofiltration steps work in conjunction with another to form a continuous concentration process. However, as stated in the prior art rejection, the art combination is specifically using a nanofiltration membrane to concentrate Mg and remove Na (see e.g. Thorsen - page 1, lines 21-22). This step does not require steps before or after because the process just needs a nanofilter capable of separating the two ions (see e.g. page 3, paragraph starting with “In Step 2”). The subsequent steps of Thorsen were for specifically precipitating gypsum and removing calcium (see e.g. page 4, paragraph starting with “In After the calcium”), which is not a concern for Scott. Thus, a person having ordinary skill in the art would understand it would not be needed unless the gypsum and calcium also needed to be removed.
On page(s) 4, the Applicant argues that ‘Neither Thorsen nor Scott articulate any reason or motivation to alter the process of Scott, with an additional step that is unnecessary to Scott’s process… Rather than accentuate a need for a nanofiltration process, Scott’s description contradicts the need for a filtration step to concentrate Mg2+, as the dissolution of olivine in HCI actually causes the resulting Mg2+ concentration to be even higher than that of seawater (i.e., the feed solution of Thorsen) (Scott, at para. [0192]). Since HCI promotes the solubility of olivine and resultingly, the concentration of Mg, there is no motivation to add a nanofiltration step to further concentrate Mg2+ as doing so would be redundant and add to the cost and complexity of the process.’ This is not considered persuasive. The invention of Scott is designed to process magnesium silicate and isolating different parts into desired products, such as MgOH (see e.g. [0001]). Part of this process involves digesting an input, such as olivine, with acid (see e.g. [0191]), which causes an increased concentration of Mg ions. Following this process, the Mg concentration is further increased through various processing steps wherein other ions, such as iron are removed (see e.g. Fig 1). Sodium ions are introduced into the system (see e.g. [0128]). Thorsen also teaches a method of isolating magnesium from a feed (see e.g. page 1, lines 1-3), wherein sodium ions are separated from the magnesium ions using a nanofilter (see e.g. page 1, lines 21-22). Therefore, it would be obvious to a person having ordinary skill in the art before the effective filing date of the instant invention that the product stream of Scott can be further purified, improving the quality of the product, by introducing a nanofilter to remove any of the monovalent ions, such as sodium.
On page(s) 5, the Applicant argues that ‘adding the nanofiltration process of Thorsen to the process of Scott would result in the magnesium hydroxide product becoming so concentrated within the solution that it precipitates out. The addition of such a process to the methodology of Scott would defeat the need for subsequent electrolysis, altering fundamental steps of the process’. This is not considered persuasive. There is no evidence in either reference that passing the stream of Mg and Na through the nanofilter would generate precipitation because Thorsen only teaches this occurring using multiple nanofilters specifically designed to cause these precipitations and none of these precipitations are Mg salts.
On page(s) 5, the Applicant argues that ‘Thorsen describes that the filtration process causes gypsum to precipitate inside the filter itself (Thorsen, at page 2, lines 14-18). The deposition of products directly onto the nanofiltration unit would make it impossible to carry out electrolysis, a process which would require ions in a solution. Such a modification to the process of Scott would render any nanofiltration inoperable’. This is not considered persuasive. The Applicant is pointing specifically to the second nanofilter of Thorsen, which was designed to remove gypsum and would not necessarily be used in the combination, as explained above. Furthermore, the method of Scott also uses settling methods to separate out precipitates (see e.g. [0193]) and thus a person having ordinary skill in the art would be able to account for such things.
On page(s) 5, the Applicant argues that ‘Thorsen is silent with respect to the separation of monovalent and divalent ions from a solution by using a nanofiltration membrane.’. This is not considered persuasive. Thorsen explicitly discloses “Sea water is fed to a first nanofiltration unit with selective concentration of divalent ions in solution (e.g. Mg2+, Ca2+, SO 2") and therefore sodium chloride is reduced relatively and gradually removed with the permeate” (see e.g. page 2, lines 12-14).
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.
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/ALEXANDER W KEELING/Primary Examiner, Art Unit 1795