DETAILED ACTION
Citation to the Specification will be in the following format: (S. # : ¶/L) where # denotes the page number and ¶/L denotes the paragraph number or line number. Citation to patent literature will be in the form (Inventor # : LL) where # is the column number and LL is the line number. Citation to the pre-grant publication literature will be in the following format (Inventor # : ¶) where # denotes the page number and ¶ denotes the paragraph number.
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 .
Status of Application
The preliminary amendment dated 5/8/2024 has been received and will be entered.
Claim(s) 22-41 is/are pending.
Claim(s) 1-21 is/are acknowledged as cancelled.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on:
5/20/2026
5/6/2025
1/13/2025
7/25/2024
5/8/2024
are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Claim Rejections - 35 USC § 112
112(b)
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.
I. Claims 38-39 – or as stated below – is/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.
Claim 38 recites “the attack mixture 5.” This lacks antecedent basis.
Claim 39 recites “the attack mixture 5.” This lacks antecedent basis.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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.
I. Claim(s) 22, 23, 24, 25, 26, 28, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, and 41 – or as stated below - is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2011/0200509 to Takhim.
Citation is for the convenience of the reader, assumed to be of skill in the art. The rejection should be understood as being over the entire reference, and not just those portions called out.
With respect to Claim 22, this claim requires “ (a) provision of a phosphate mineral source.” The phosphate salt is interpreted as a phosphate mineral source. (Takhim 1: [0010], [0021]). See also (Takhim 4: [0069]: “Phosphate Rock”).
Claim 22 further requires “(b) acid attack of the phosphate mineral source by a concentrated strong acid aqueous solution to obtain an attack mixture, wherein the strong acid is selected from the group consisting of HCl, H2SO4, HNO3, and a mixture thereof, and wherein the strong acid aqueous solution has a concentration of acid that is above 20 wt.% based on the total weight of the strong acid aqueous solution.” An attack with a strong acid is taught. (Takhim 1: [0010]). At least hydrochloric acid is taught. (Takhim 1 [0021]). The concentration is taught. (Takhim 2: [0038]; 4: [0070]).
Claim 22 further requires “(c) dilution in water and/or a water-containing solution of the attack mixture to obtain a monocalcium phosphate solution.” Dilution is taught. (Takhim 4: [0070]). Monocalcium phosphate (MPC) is taught. Id.
Claim 22 further requires “(d) filtration of the monocalcium phosphate solution to obtain a residue comprising one or more impurities and a filtrate being a filtered monocalcium phosphate solution.” Filtration is taught. Id.
Claim 22 further requires “(e) acidulation of the filtered monocalcium phosphate solution by a strong acid selected from the group consisting of HCl, H2SO4, HNO3, and a mixture thereof, to obtain a phosphoric acid solution.” Acidulation with sulfuric acid is taught. (Takhim 4: [0072]). Phosphoric acid is produced. Id.
Claim 22 further requires “(f) optional pre-purification of the phosphoric acid solution to obtain a pre-purified phosphoric acid solution.” As this step is optional, the Examiner exercises his option of not addressing it.
Claim 22 further requires “(g) separation through a membrane of the phosphoric acid solution or of the pre-purified phosphoric acid solution to recover a purified phosphoric acid solution, wherein the membrane is selected from the group consisting of a diffusion dialysis acid separation membrane, an electrodialysis-driven depletion membrane, and a nanofiltration membrane.” Takhim teaches separation with a 0.45 µm membrane. (Takhim 5: [0081]). To the extent this is not a “nanofiltration membrane,” use of a nanofiltration membrane is an obvious expedient. As the Specification admits, employing nanofiltration membranes in the synthesis of phosphoric acid is old and known. See (S. 1: [0005], [0007]). One of skill in the art would be motivated to employ a nanofiltration membrane because – as the Specification admits – “impurities can be a nuisance and must therefore be removed.” (S. 1: [0003]). The Specification admits “[m]any processes are known for purifying phosphoric acid or producing high-purity phosphoric acid.” Id. “[A]n implicit motivation to combine exists not only when a suggestion may be gleaned from the prior art as a whole, but when the improvement’ is technology-independent and the combination of references results in a product or process that is more desirable, for example because it is stronger, cheaper, cleaner, faster, lighter, smaller, more durable, or more efficient. Because the desire to enhance commercial opportunities by improving a product or process is universal-and even common-sensical-we have held that there exists in these situations a motivation to combine prior art references even absent any hint of suggestion in the references themselves. In such situations, the proper question is whether the ordinary artisan possesses knowledge and skills rendering him capable of combining the prior art references.” DyStar Textilfarben GmbH & Co. Deutschland KG v. C.H. Patrick Co., 464 F.3d 1356, 1368, 80 USPQ2d 1641, 1651 (Fed. Cir. 2006) (emphasis added). Alternatively or additionally, the combination reflects application of techniques the Specification admits are old and known to achieve predictable results. This does not impart patentability. MPEP 2143; KSR.
As to Claim 23, phosphate rock is taught. (Takhim 4: [0069]).
As to Claim 24, the attack is taught. (Takhim 1: [0021]; 2-3: [0052]). Carrying out the attack for the claimed time is an obvious expedient for any number of reasons, for example treating a given amount of phosphate rock. The skilled artisan is not an automaton. KSR, 550 U.S. 398, 421 (2007). Treating or “attacking” 2 tons of phosphate rock would take more time than 2 ounces.
As to Claim 25, the rational expressed in connection with the rejection of Claim 24 applies here.
As to Claim 26, the pH is taught. (Takhim 2: [0052]).
As to Claim 28, purification with activated carbon is taught. (Takhim 3: [0055]).
As to Claim 30, addition of a second strong acid is taught. (Takhim 1: [0014]).
As to Claim 31, 22% P2O5 is taught. (Takhim 4: [0073]).
As to Claim 33, concentration is taught. (Takhim 2: [0047]).
As to Claim 34, recycling is taught. (Takhim 2: [0048]).
As to Claim 35, the P2O5 content is taught. (Takhim 2: [0052]).
As to Claim 36, the H2SO4 is taught. (Takhim 3: [0054]).
As to Claim 37, the acids/concentrations are taught. (Takhim 2: [0038]; 4: [0070]).
As to Claim 38, notwithstanding the issues above, the rationale expressed in the rejection of Claim 24 applies here, mutatis mutandis.
As to Claim 39, notwithstanding the issues above, the rationale expressed in the rejection of Claim 24 applies here, mutatis mutandis.
As to Claim 40, the rationale expressed in the rejection of Claim 24 applies here, mutatis mutandis.
As to Claim 41, crystallization is taught. (Takhim 3: [0058]; passim).
II. Claim(s) 27 and 32 – or as stated below - is/are rejected under 35 U.S.C. 103 as being unpatentable over US 2011/0200509 to Takhim in view of:
(i) Duan, et al., A polysulfone-based anion exchange membrane for phospohoric acid concentration and purification by electro-electrodialysis, Journal of Membrane Science 2018; 552: 86-94 (hereinafter “Duan at __”).
The discussion accompanying “Rejection I” above is incorporated herein by reference.
As to Claim 27, to the extent Takhim may not teach dialysis purification of phosphoric acid, Duan does. (Duan at 65 – 2. Experimental, et seq.). Polysulfone membranes are taught. Id. One of skill in the art would be motivated to purify with a dialysis membrane for the high current efficiency, low energy consumption, etc. (Duan at 83, col. 2 – 4. Conclusions).
As to Claim 32, tanks, plates, etc. are taught. (Duan at 88, Fig. 1-2).
Allowable Subject Matter
I. Dependent upon a rejected base claim
Claim 29 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.
Search of the prior art did not teach or reasonably suggest adjusting the molar ratio as claimed at the particular stage in the process, as claimed.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DANIEL C. MCCRACKEN whose telephone number is (571) 272-6537. The examiner can normally be reached on Monday-Friday (9-6).
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/DANIEL C. MCCRACKEN/Primary Examiner, Art Unit 1736
Prosecution Insights