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 without traverse of claims 1-10 and 13-17 in the reply filed on 11/21/2025 is acknowledged. However, claim 17 is dependent of withdrawn claim 11, therefore, is also withdrawn.
Claims 11-12 and 17 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 11/21/2025.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-10 and 13-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 1 recites the broad recitation “n membrane units (M1 – Mn), with n ≥ 1” (refer line 7), and the claim also recites “arranged in series” in the same line which is the narrower statement of the range/limitation because it requires “n” to be greater than 1 in order to be arranged in series. The claim(s) are considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claims.
Regarding claim 1, the limitations “n membrane units (M1-Mn), with n ≥ 1, arranged in series” in line 7 and “if n > 1, feeding at least a fraction of…” in line 19 renders the claim indefinite because it is unclear whether the claim requires a plurality of membrane unit.
Regarding claim 1, the limitation “with one or more other flows” in line 14 renders the claim indefinite because claim fails to define what “other flows” are.
Regarding claim 9, the phrase "preferably" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention.
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 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-2, 6-7, 9-10, and 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skidmore et al. (US 5945000), Harasek et al. (US 2012/0238777), and Orita (WO 2009-119684A1, refer English language machine translation for claim mapping).
Regarding claim 1, Skidmore teaches a process for purifying a phosphate containing acidic solution (phosphoric acid solution) (refer abstract), comprising feeding the phosphate containing acidic solution through a nanofiltration station (refer housings 54 comprising a plurality of elements 52) comprising a plurality of nanofiltration membrane units (52) arranged in series (refer fig. 3, 4, 5). The nanofiltration membrane units (52) produces permeate and retentate, permeate of one unit is supplied as feed to another unit, and reject/retentate of units (52) is collected and returned to feed of the units (52) (refer 62 returning rejects 60 to feed 50).
Skidmore does not teach providing a first recovery membrane unit, feeding a fraction of the first retentate (retentate of first NF module) to the first recovery membrane unit producing first recovery permeate and first recovery retentate, and feeding at least a fraction of the first recovery permeate to entry line for combination with phosphate containing acid solution.
Harasek teaches a process for concentrating a material solution comprising a plurality of membrane separating stages (refer abstract), the process comprising separating a material solution (11) into a permeate (13) and retentate (12) using a separation membrane module (1), the retentate (12) is supplied to a second separation membrane module (2) prior to returning to the material solution (11) (refer fig. 2). The retentate (12) is separated into a permeate (23) and retentate (22), the permeate (23) is returned to the material solution feed (11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the process of Skidmore to supply retentate of the first feeding a fraction of the first retentate (retentate of first NF module) to the first recovery membrane unit producing first recovery permeate and first recovery retentate, and feeding at least a fraction of the first recovery permeate to entry line for combination with phosphate containing acid solution to control concentration of material in the return stream as taught by Harasek.
Modified Skidmore does not teach that the phosphoric acid solution has a pH of less than 2. However, Orita discloses treating of phosphoric acid solution having a pH of less than 2 by supplying the phosphoric acid solution to a membrane unit (4) (refer abstract, fig. 1). It would have been obvious to one of ordinary skill in the art to use phosphoric acid solution having a pH of less than 2 in the process of modified Skidmore because Orita establishes that it is known in the art to use membrane filtration for purification of phosphoric acid solution having a pH of less than 2.
Regarding claim 2, modified Skidmore teaches limitations of claim 1 as set forth above. In fig. 3, Skidmore discloses housing (54) comprising 6 nanofiltration membrane units arranged in series, and retentate from each of the nanofiltration membrane units is combined and returned to the feed (refer stream 62). Harasek disclosed treating retentate stream prior to returning to feed (refer rejection of claim 1 above).
Regarding claims 6 and 7, modified Skidmore teaches limitations of claim 1 as set forth above. In fig. 2, Harasek discloses that 100% of first recovery permeate (permeate of module 2) is returned to feed (11) with a single permeate recirculation loop formed between the permeate and feed (Refer fig. 2).
Regarding claim 9, modified Skidmore teaches limitations of claim 1 as set forth above. Skidmore discloses (table 1) permeate having 18.50% P2O5 and total organic carbon of about 6% compared to the feed. Skidmore does not disclose less than 100 ppm particles larger than 1 micron, however, selecting pore size of nanofiltration membrane to achieve desired separation characteristics with regards to size of the particles and TOC removal rates would have been an obvious matter of design choice to one of ordinary skill in the art.
Regarding claim 10, modified Skidmore teaches limitations of claim 1 as set forth above. Skidmore discloses that impurities comprise Al, Ca, Cr, Fe, and Mg (abstract, table 1). Oen of ordinary skill in the art would have had a reasonable expectation of success in applying the method of modified Skidmore to other impurities such as Ca, and Cr due to close structural similarities with impurities disclosed by Skidmore. Regarding the removal rate, Harasek discloses use of nanofiltration membranes to produce P2, refer module 22 in fig. 2, paragraph [0013]. Since the claimed membrane and membrane disclosed by Harasek are same or similar (nanofiltration membranes), claimed recovery % would be inherent.
Regarding claim 14, modified Skidmore teaches limitations of claim 1 as set forth above. Harasek discloses treating the retentate 12 of unit 1 with another unit 2 before returning to feed of unit 1. Skidmore discloses that nanofiltration module comprises a plurality of nanofiltration units connected in series (Refer fig. 3 wherein housing 54 comprising a plurality of units 52). Use of nanofiltration module having a plurality of units in series for treatment of retentate would have been obvious to one of ordinary skill in the art because Skidmore discloses that such modules are known in the art.
Claim(s) 8 and 16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Skidmore et al. (US 5945000), Harasek et al. (US 2012/0238777), and Orita (WO 2009-119684A1, refer English language machine translation for claim mapping) as applied to claim 1 above, and further in view of Han et al. (KR 20160010832, refer attached English language machine translation for claim mapping).
Regarding claims 8 and 16, modified Skidmore teaches limitations of claim 8 as set forth above. Orita discloses providing ion exchange unit (6) to further process permeate of the first membrane unit (4). Orita does not disclose removal of residual cations using ion exchange unit (6).
Han teaches a method to remove metal ions in a phosphoric acid solution comprising a step of activating an ion exchange resin by passing an acid solution through the ion exchange resin (refer abstract), wherein the ion exchange resin is cation exchange resin (refer page 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the process of modified Skidmore to treat permeate of the first NF unit through a cation exchange resin to remove metal ion impurities from the phosphoric acid solution as taught by Han. Selecting type of cation exchange resins to enable removal of cation impurities comprising mono and divalent cations would have been an obvious matter of choice to one of ordinary skill in the art based on expected impurities of the phosphoric acid solution.
Allowable Subject Matter
Claim 3, 4, 5, 13 and 15 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims. Claims 3, 4, 5, 13 and 15 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
The cited prior arts fail to teach or suggest the method of claim 1 wherein at least a fraction of the first recovery retentate (Prr1) issued out of the first recovery membrane unit (Mr1) is fed to the retentate side of the second recovery membrane unit (Mr2) wherein at least a fraction of the second recovery permeate (Ppr2) is, fed to the entry line (1e), thus forming one of the one or more permeate recirculation loops, and combined with the phosphate containing acidic solution (P1) to contribute to the formation of the input phosphate solution (Pf), and/or sent out of the nanofiltration unit (2) and recovered as a nanofiltered phosphate recovery solution (P2r) as claimed in claim 3. Claim 4 is dependent of claim 3.
The cited prior arts fail to teach or suggest the method of claim 1 wherein at least a fraction of the first recovery permeate (Ppr1) is fed to the exit membrane unit (Me1), and wherein at least a fraction of the first exit permeate (Ppe1) is fed to a retentate side of a second exit membrane unit (Me2) for separating the first exit permeate (Ppe1) into two streams: a second exit permeate (Ppe2) poor in the impurities, and a second exit retentate (Pre2) rich in the impurities, wherein at least a fraction of the second exit permeate (Ppe2) is sent out of the nanofiltration station (2) and forms a nanofiltered phosphate exit solution (P2e), and wherein at least a fraction of the second exit retentate (Pre2) is fed to the entry line (le) forming a retentate recirculation loop, and combined with the phosphate containing acidic solution (P1) to contribute to the formation of the input phosphate solution (Pf) as claimed in claim 5.
The cited prior arts fail to teach or suggest the method of claim 1 wherein the first exit membrane unit (Me1) is present as claimed in claim 13.
The cited prior arts fail to teach or suggest the method of claim 1 wherein the fraction of the first recovery permeate (Ppr1) fed to the exit membrane unit (Me1) is from 10 to 100 wt.% as claimed in claim 15.
Conclusion
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/PRANAV N PATEL/Primary Examiner, Art Unit 1777