DETAILED ACTION
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 04/27/2026 has been entered.
Response to Amendment
In response to the amendment received on 04/27/2026:
claims 1-17 are currently pending
claims 8-10 and 13-16 are withdrawn from consideration
claims 1 and 11 are amended
new prior art grounds of rejection applying Vlasopoulos, Pisch and Sanna are presented herein
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The text of those sections of Title 35 U.S. Code not included in this action can be found in a prior Office Action.
Claims 1-7 and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Vlasopoulos et al. (WO 2012/028418 A1), hereinafter referred to as VLASOPOULOS, in view of Pisch et al. (WO 2014/082996 A1), hereinafter referred to as PISCH.
Regarding claim 1, VLASOPOULOS teaches process of CO2 mineralization (lines 4-5, p. 1: process for the production of the components from magnesium silicates and carbon dioxide), comprising:
reacting CO2 (lines 28-29, p. 5: feeding slurry to a reactor in which it is continuously contacted with carbon dioxide) with a natural mineral phase having a prevalent alkaline-earth metals silicate (line 26, p. 5: particulate magnesium silicate, and lines 25-28, p. 6: examples of particulate magnesium silicate containing material are readily-available minerals such as olivines, serpentines and talcs) content in the form of fine particulate matter (line 34, p. 6 and line 1, p. 7: it is preferred to grind or mill them (magnesium silicate ore particles) so that their average particle size is in the range 100 to 500 microns) in an aqueous slurry (lines 26-27, p. 5: producing a slurry in water)
including up to 35% by weight of a finely ground mineral phase (lines 11-12, p. 7: the slurry contains up to 60% by weight of the particulate magnesium silicate). VLASOPOULOS teaches range of up to 60%, which overlaps with the claimed range of up to 35%. 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); see MPEP §2144 (I); and
an alkali metal carbonate or bicarbonate (lines 13-15, p. 7: a salt of carbonic acid (sodium carbonate or potassium carbonate) is added to step (a))
at a temperature of 50 to 300°C (line 4, p. 8: at a temperature in the range of 40 to 250°C; VLASOPOULOS teaches range of 40 to 250°C, which overlaps with the claimed range of 50 to 300°C) and a CO2 pressure ≥ 1.0 MPa (line 9, p. 8: the pressure is maintained in the range from 0.5 to 25 MPa; VLASOPOULOS teaches range of 0.5 to 25 MPa, which overlaps with the claimed range of ≥ 1.0 MPa) and
washing a solid product obtained from the reaction with water (line 27, p. 9: the particulate material/magnesium carbonate recovered in step (d) is suitably washed);
the solid carbonated material having pozzolanic properties useful as a supplementary cement material for cements (see VLASOPOULOS at lines 31-33, p. 10: the particulate products of step (e) and (g) can be used in the formulation of cement binders which have a lower carbon footprint than Portland cement; and lines 10-17: the particulate product in step (e) comprises silica…, “silica” includes both the various oxides of silica and/or solid metal silicate salts). “Silica” reads on the limitation “material having pozzolanic properties”.
While VLASOPOULOS teaches that the particulate material/magnesium carbonate recovered in step (d) is suitably washed (see VLASOPOULOS at line 27, p. 9), VLASOPOULOS fails to explicitly teach washing until substantial removal of an alkaline metal to obtain a solid carbonated material having a total concentration of Na and/or K lower than 2% by weight with respect to the total weight of the solid carbonated material dried in air at 120°C for 2 hours.
However, PISCH teaches a process for the production from magnesium silicate rock of alkali metal magnesium orthosilicates and magnesium oxide and/or alkali metal silicates which can be used subjected to further treatments to produce a number of useful products (see PISCH at lines 5-9, p. 2). PISCH also teaches that such minerals include olivines (see PISCH at line 18, p. 3). Additionally, PISCH teaches that during CO2 treatment, the alkali metal magnesium orthosilicate compound can react directly with CO2 as indicated by equations (7) and making use of an alkali bicarbonate solution to achieve the same reaction (8) (see PISCH at lines 5-10, p. 12):
PNG
media_image1.png
44
764
media_image1.png
Greyscale
PNG
media_image2.png
40
804
media_image2.png
Greyscale
Finally, PISCH teaches that R represents alkali metal (see PISCH at lines 16-17, p. 2), the alkali metal is preferably potassium or sodium (see PISCH at line 27, p.2), and solution is aqueous solution (see PISCH at line 16, p. 10). Equations (7) and (8) indicate that besides the solid target material such as magnesium carbonate and silica, the other product formed is water-soluble sodium or potassium carbonate.
One of ordinary skill in the art would have expected to form water-soluble potassium or sodium carbonate as disclosed by PISCH in the process of VLASOPOULOS based on teachings of VLASOPOULUS disclosing that sodium hydrogen carbonate or potassium hydrogen carbonate present in the reaction slurry (see VLASOPOULUS at lines 13-15, p. 7) and based on teachings of PISCH describing the products of the carbonation reaction (see PISCH at equations (7) and (8), p. 12).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have expected the alkali metal residues to be Na or K in the process of VLASOPOULOS because PISCH discloses formation of water-soluble potassium or sodium carbonate.
Additionally, PISCH teaches the effectiveness of water leaching (see PISCH at Example 9, Table, p. 22). The data presented in the table indicates that after washing with water, potassium was removed from the product, and the majority of sodium was removed within first 4 washes. PISCH also teaches that the product was washed, filtered and dried overnight at 110°C; and that the washing can be used to enhance Na recycling in the process (see PISCH at lines 11-15, p. 22). VLASOPOULOS discloses that the particulate material (magnesium carbonate and silica) is suitably washed and dried (see VLASOPOULOS at lines 27-28, p. 9), but is silent with respect to the duration or temperature. However, since PISCH discloses the CO2 treatment of the alkali metal magnesium orthosilicate compound, and MPEP states that "[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" (see MPEP § 2144.05(II)(A)), it would have been obvious to one of ordinary skill in the art to have adjusted the drying conditions, e.g., duration and temperature, as disclosed by PISCH to be within the claimed range.
One of ordinary skill in the art would have recognized that washing the solid product of VLASOPOULOS would result in removing alkali metal residues such as K and enhance Na recycling in the process, as disclosed by PISCH (see PISCH at lines 11-15, p. 22).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have washed the product obtained by VLASOPOULOS to obtain material having a total concentration of K lower than 2% as disclosed by PISCH.
While VLASOPOULOS as modified by PISCH is silent with respect to P7 index being higher than 0.9, VLASOPOULOS as modified by PISCH teaches each and every process step and limitation of the applicant' s claims as set forth. Therefore, to P7 index being higher than 0.9 is inherently disclosed. See MPEP §2112.01(I): “where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best”.
Please note, the statement “optionally in mixed phase with one or more transition metals selected from one or more of the group consisting of Fe, Mn, and Ni” is not considered a positive claim limitation.
Regarding claim 2, VLASOPOULOS as modified by PISCH teaches process according to claim 1, further comprising the following stages:
preparing a first slurry of the natural mineral powder phase (see VLASOPOULUS at lines 26-27, p. 5: step (a): producing a slurry of a particulate magnesium silicate in water) having a diameter d90 ≤ 300 µm (see VLASOPOULUS at line 34, p. 6 and line 1, p. 7: it is preferred to grind or mill them (magnesium silicate ore particles) so that their average particle size is in the range 100 to 500 microns; VLASOPOULOS teaches range of 100 to 500 µm, which overlaps with the claimed range of ≤ 300 µm) in an aqueous solution in the presence of an alkaline carbonate or bicarbonate (see VLASOPOULUS at lines 13-15, p. 7: a salt of carbonic acid (sodium carbonate or potassium carbonate) is added to step (a)) with an initial concentration of the solid equal to or less than 35% by weight with respect to the weight of the first slurry (see VLASOPOULUS at lines 11-12, p. 7: the slurry fed to step (a) contains up to 60% by weight of the particulate magnesium silicate; VLASOPOULOS teaches range of up to 60% by weight, which overlaps with the claimed range of equal or less than 35% by weight);
reacting the first slurry obtained in stage a) in a suitable reactor with CO2 maintained at a pressure ≥ 2 MPa and at a temperature ranging from 50 to 300°C to obtain a second slurry (see VLASOPOULUS at lines 28-31, p. 5: step (b): feeding slurry to at least one first reactor in which it is continuously contacted with carbon dioxide, a soluble salt of carbonic acid at a temperature in the range from 25 to 250°C, a pressure in the range from 0.5 to 25 MPa; VLASOPOULOS teaches ranges from 25 to 250°C and 0.5 to 25 MPa, which overlaps with the claimed ranges of 50 to 300°C and ≥ 2 MPa);
discharging the second slurry obtained in step b) (see VLASOPOULUS at lines 32-33, p. 5: step (c): withdrawing from at least said first reactor a slurry comprising a mother liquor and particulate material comprising a magnesium carbonate) and separating the solid phase (see VLASOPOULUS at line 34, p. 5: step (d): separating said particulate material from said mother liquor);
washing the solid phase obtained in step c) with water until removal of alkali metal residues (see VLASOPOULUS at line 27, p. 9: the particulate material/magnesium carbonate recovered in step (d) is suitably washed) and separating it in order to obtain the solid carbonated material (see VLASOPOULUS at line 34, p. 5: step (d): separating said particulate material from said mother liquor) and, optionally,
drying the thus obtained solid material (line 27, p. 9: the particulate material/magnesium carbonate recovered in step (d) is suitably washed and dried).
Regarding claim 3, VLASOPOULOS as modified by PISCH teaches process according to claim 2, wherein the solid phase in stage c) or the solid phase in step d) is separated by filtration, decantation or centrifugation (see VLASOPOULUS at lines 13-15, p. 9: the particulate material/magnesium carbonate is recovered from the slurry in step d) by any known separation technique which can be used on an industrial scale such as filtration, decanting).
Regarding claim 4, VLASOPOULOS as modified by PISCH teaches process according to claim 1, wherein the natural mineral phase is olivine (see VLASOPOULUS at lines 25-28, p. 6: examples of particulate magnesium silicate containing material are readily-available minerals such as olivine).
Regarding claim 5, VLASOPOULOS as modified by PISCH teaches process according to claim 1, wherein the concentration of the alkaline carbonate or bicarbonate in the aqueous slurry or in the first slurry of the stage a) ranges between 0.1 and 2.0 M (see VLASOPOULUS at lines 18-20, p. 14: slurry containing olivine particles having an average size of 120 microns and 0.64 M of sodium hydrogen carbonate; VLASOPOULOS teaches 0.64 M, which is within the claimed range of 0.1 to 2.0 M).
Regarding claim 6, VLASOPOULOS as modified by PISCH teaches process according to claim 2, wherein the temperature in stage b) varies between 120 and 170°C (see VLASOPOULUS at lines 28-31, p. 5: step (b): feeding slurry to at least one first reactor in which it is continuously contacted with carbon dioxide, a soluble salt of carbonic acid at a temperature in the range from 25 to 250°C; VLASOPOULOS teaches range of 25 to 250°C, which overlaps with the claimed range of between 120 and 170°C).
Regarding claim 7, VLASOPOULOS as modified by PISCH teaches process according to claim 1, wherein the concentration of mineral phase in the slurry is from 25 to 35% by weight (see VLASOPOULUS at lines 11-12, p. 7: the slurry contains up to 60% by weight of the particulate magnesium silicate; VLASOPOULOS teaches range of up to 60% by weight, which overlaps with the claimed range of 25 to 35% by weight).
Regarding claim 11, VLASOPOULOS as modified by PISCH teaches process according to claim 1, wherein the prevalent alkaline-earth metals silicate content is Mg, Ca, or a mixture thereof (see VLASOPOULUS at line 25, p. 6: step (a) of the process can employ any particulate magnesium silicate), and wherein the alkali metal carbonate or bicarbonate is Na, K, or a mixture thereof (see VLASOPOULUS at lines 13-15, p. 7: a salt of carbonic acid (sodium carbonate or potassium carbonate).
Regarding claim 12, VLASOPOULOS as modified by PISCH teaches process according to claim 1, wherein the alkaline carbonate or bicarbonate is Na, K, carbonate or bicarbonate, or a mixture thereof (see VLASOPOULUS at lines 13-15, p. 7: a salt of carbonic acid (sodium carbonate or potassium carbonate), wherein a reactor is maintained at constant pressure (see VLASOPOULUS at line 9, p. 8: the pressure is suitably maintained), wherein the mother liquors are recycled into stage a) (see VLASOPOULUS at lines 15-16, p. 9: the depleted mother liquor is recycled to either or both of steps (a) and (b)), wherein alkali metal residues are of Na and/or K (see rejection of claim 1 above and PISCH at equations (7) and (8), p. 12), and wherein the solid carbonated material is dried (see VLASOPOULUS at line 27, p. 9: the particulate material/magnesium carbonate recovered in step (d) is suitably washed and dried).
Claim 17 is rejected under 35 U.S.C. 103 as being unpatentable over VLASOPOULOS in view of PISCH as applied to claim 1 above, and further in view of Sanna et al. (A review of mineral carbonation technologies to sequester CO2. Chem. Soc. Rev. 2014, 43, 8049), hereinafter referred to as SANNA.
Regarding claim 17, VLASOPOULOS as modified by PISCH teaches process according to claim 1.
While VLASOPOULOS discloses the method of carbonation of mineral ores rich in magnesium silicates such as olivines, serpentines and talcs (see VLASOPOULOS at lines 25-28, p. 6), VLASOPOULOS fails to explicitly teach wherein the natural mineral phase is wollastonite.
However, applicability of the aqueous CO2 mineralization of metal silicates including magnesium and calcium silicates in the presence of bicarbonate is known in the art, as evidenced from the disclosure of SANNA describing carbonation potential and reactivity of Ca, Fe2+ and Mg containing silicates (see Table 2). SANNA discloses that silicate rocks containing the desired Mg and Ca have been targeted for mineral carbonation; and serpentine, olivine, and to less extent wollastonite because of its lower abundance, are preferred based on performance and availability (see SANNA at 3.1 Processes developed for minerals, left column, 1st paragraph, p. 8056). SANNA discloses carbonation reaction conditions very similar to the ones taught by VLASOPOULOS: 150 atm/15 Mpa, 185°C and 0.64 M sodium hydrogen carbonate (see SANNA at Table 2); VLASOPOULOS teaches ranges from 25 to 250°C and 0.5 to 25 MPa, and 0.64 M of sodium hydrogen carbonate (see VLASOPOULUS at lines 28-31, p. 5 and lines 18-20, p. 14). Carbonation results presented by SANNA in Table 2 (see Eco2(%): reaction efficiency) indicate similar carbonation efficiency for serpentine, olivine (as disclosed by VLASOPOULOS) and wollastonite.
One of ordinary skill in the art would have anticipated success when using calcium silicate mineral such as wollastonite as a feedstock in the mineralization process of VLASOPOULOS based on the teachings of SANNA describing that silicate rocks containing the desired Mg and Ca have been targeted for mineral carbonation; and serpentine, olivine, and wollastonite are preferred based on performance and availability (see SANNA at 3.1 Processes developed for minerals, left column, 1st paragraph, p. 8056).
Response to Arguments
Applicant's arguments filed on 04/27/2026 have been fully considered but they are not persuasive.
Applicant argues that the Office Action mailed on 01/13/2026 incorrectly equates the claimed step of “e. washing a solid product obtained from the reaction with water until substantial removal of an alkaline metal to obtain a solid carbonated material” with VLASOPOULOS’s disclosure “the particulate material/magnesium carbonate recovered in step (d) is suitably washed” (see VLASOPOULOS at line 27, p. 9), and alleges that a P7 index higher than 0.9 is inherently disclosed (see Remarks received on 04/27/2026 spanning paragraphs on pages 5-6).
However, the examiner respectfully disagrees for the following reasons. As was discussed in the rejection of claim 1 above, VLASOPOULOS discloses that the particulate material (magnesium carbonate and silica) is suitably washed and dried (see VLASOPOULOS at lines 26-28, p. 9), additionally, PISCH explicitly teaches leaching of alkali metals, e.g., Na and K, while washing (see PISCH at Table in Example 9, p. 22). Therefore, the inclusion of washing step disclosed by PISCH would result in removing the majority of the water-soluble Na and/or K residues. Furthermore, the previously presented inherency argument is not based on the disclosure of VLASOPOULOS describing suitable washing, but a combination of VLASOPOULOS and PISCH. VLASOPOULOS as modified by PISCH teaches each and every process step and limitation of the applicant's claims as set forth, including washing the obtained particulate material so that a total concentration of Na and/or K lower than 2% by weight. Thus, P7 index being higher than 0.9 is presumed to be inherent according to MPEP §2112.01(I): “where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best”.
Applicant argues that “suitably washed” in the context of VLASOPOULOS necessarily refers to the removal of nitrate anions, and that if nitrate anions are not removed, they would generate NO2 during the subsequent heating step (see Remarks received on 04/27/2026 spanning paragraphs on page 6). Applicant also refers to the disclosure of VLASOPOULOS describing that the nitrate anions derive from nitrate salt added to improve solubility of magnesium silicate. To support the argument Applicant cites lines 27-32 on p. 9 and lines 20-23, p. 7 of VLASOPOULOS.
However, the examiner respectfully disagrees for the following reasons. It is noted that besides adding aforementioned nitrate salt, VLASOPOULOS also discloses addition of salt of carbonic acid (most preferably selected from sodium carbonate, sodium hydrogen carbonate, potassium carbonate and potassium hydrogen carbonate) (see VLASOPOULOS at lines 13-14, p. 7). Please note, that Applicant’s assertion that “suitably washed” in the context of VLASOPOULOS necessarily refers to the removal of nitrate anions is not supported by factual evidence, and thus is mere attorney arguments, and that it’s the burden of the Applicant to offer facts to support the positions.
Applicant argues that a washing of three times yields P7 index of 0.907, and a product that is “suitably washed” according to VLASOPOULOS could be a product subjected to one washing (see Remarks received on 04/27/2026 spanning paragraphs on page 7).
However, the examiner respectfully disagrees for the following reasons. As was discussed in the rejection of claim 1 above, VLASOPOULOS as modified by PISCH teaches washing the obtained particulate material. Furthermore, PISCH explicitly teaches washing a product in deionized water 6 times (see PISCH at line 4, p. 22).
In response to Applicant argument that VLASOPOULOS does to disclose that suitably washed means complete removal of Na/K, it is noted, that as set forth, claim 1 recites “washing a solid product obtained from the reaction with water until removal of an alkali metal to obtain a solid carbonated material having a total concentration of Na and/or K lower than 2% by weight with respect to the total weight of the solid carbonated material”.
Applicant argues that the Action asserts a P7 index higher than 0.9 is implicit in Pisch, since the product of Example 9 (Pisch) after 5-6 repeated washings shows a sum of Na and K lower than 2%; that this assertion should be reconsidered, as the table at Example 9 indicates the product after 5-6 repeated washings has a content of 1.3% of Na ion (with no K content); table 1 of the present application indicates a sample Ex.2-L1 that contains 1.3% of Na ion (with no K content) and has a P7=0.771 (Table 2). See Remarks received on 04/27/2026 spanning paragraphs on page 8.
However, the examiner respectfully disagrees for the following reasons. It is noted, that as set forth claim 1, recites “washing a solid product obtained from the reaction with water until removal of an alkali metal to obtain a solid carbonated material having a total concentration of Na and/or K lower than 2% by weight with respect to the total weight of the solid carbonated material…, and a P7 index higher than 0.9”. According to MPEP § 2111, the proper claim interpretation includes giving claims their broadest reasonable interpretation. Therefore, the examiner treats the aforementioned claim limitations as indicating a solid carbonated material having a total concentration of Na and/or K lower than 2% by weight and a P7 index higher than 0.9. Thus, the Applicant’s argument regarding s sample Ex.2-L1 that contains 1.3% of Na ion (with no K content) and has a P7=0.771 (Table 2) is not commensurate in scope with claimed invention, since 1.3% is within the claimed range of lower than 2%. See MPEP §716.02(d): “Whether the unexpected results are the result of unexpectedly improved results or a property not taught by the prior art, the "objective evidence of nonobviousness must be commensurate in scope with the claims which the evidence is offered to support." In other words, the showing of unexpected results must be reviewed to see if the results occur over the entire claimed range. In re Clemens, 622 F.2d 1029, 1036, 206 USPQ 289, 296 (CCPA 1980)”.
Therefore, the rejection of claims as being unpatentable over VLASOPOULOS in view of PISCH is maintained.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to ANASTASIA KUVAYSKAYA whose telephone number is (703)756-5437. The examiner can normally be reached Monday-Thursday 7:00am-5:00pm.
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, Amber Orlando can be reached at 571-270-3149. 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.
/A.A.K./Examiner, Art Unit 1731
/ANTHONY J GREEN/Primary Examiner, Art Unit 1731
Prosecution Insights