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 . 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.
Claim Objections
Claims 11 – 16, 18, 19, 21, 22, 24, 25, 27 and 28 are objected to because of the following informalities:
Claims 11 – 16, 18, 19, 21, 24, 25, 27 and 28: there are multiple instances where a “~” is used to signify approximate ranges. Tildes generally precede a number in order to indicate an approximate value. Examiner suggests changing the “~” to “-“ or “to” and adding the word “about” before each limit of the recited range in order to signify that the recited values are approximate. For example, claim 1, line 11 reciting a pressure of “0.25 MPa ~ 0.5 MPa” may be changed to “about 0.25 MPa to about 0.5 MPa.”
Claim 11, Line 2: “an sulfite” should be “a sulfite”
Claim 19, line 2: “specifically comprises” should be changed to “further comprises”
Claim 19, line 3: “after introduction of air” should read as “after the introduction of air”
Claim 22, line 2: “after wash” should read as “after washing”
Claim 28, line 3: “and” should be added after “700 ºC;”
Appropriate correction is required.
Claim Interpretation
Claim 11 recites the limitation "mixing pyrite cinder and a sulfite evenly in water" in line 2. The term "evenly" in claim 11 may have multiple meanings such as whether "mixing pyrite cinder and a sulfite evenly" refers to creating a homogeneous solution or refers to adding even amounts of pyrite cinder and sulfite. However, claim 13 provides limitations as to the relative concentration of pyrite cinder to sulfite where the recited range does not include the instance where pyrite cinder and sulfite are added in even amounts. Therefore, examiner will interpret “mixing pyrite cinder and a sulfite evenly in water” as creating a homogeneous solution comprising pyrite cinder, a sulfite, and water.
Claim 14 recites the limitation “wherein phosphoric acid and the buffer are added to the first mixed system within 15 minutes ~ 30 minutes” in lines 1 – 2. The 15 – 30 minutes is broadly interpreted as the time corresponding to how long the phosphoric acid and buffer are added to the first mixed system. The specification discloses that phosphoric acid and buffer are added for the recited time range (see [0064]) and further provides an embodiment ([0105] specifically states “the addition of the mixed solution of phosphoric acid and sodium dihydrogen phosphate lasts for 20 minutes”), suggesting that the recited time corresponds to duration, not the time delay between obtaining the first mixed system.
Furthermore, the recited range of “15 minutes ~ 30 minutes” is interpreted as in addition to the “1 hour ~ 2 hour” leaching time in claim 11, upon which claim 14 depends upon. The specification provides an embodiment where the addition of phosphoric acid and sodium dihydrogen phosphate is 15 minutes while stirring occurs for 2 hours (see [0125]). If the 15 minutes was incorporated into the leaching time provided in claim 11, then stirring would only occur for 1 hour and 45 minutes (or 1.75 hours), suggesting that the “15 minutes ~ 30 minutes” are in addition to the “1 hour ~ 2 hour” leaching time of claim 11.
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 27 – 29 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 27 recites the limitation “adding sodium sulfide to the mother liquor to obtain a third filtrate and a third residue” in line 5. Claim 27 is incomplete for omitting an essential step, such omission amounting to a gap between the steps. See MPEP § 2172.01. The omitted step is a filtration step, such as a solid-liquid separation step. Without such a filtration step, it is unclear how the third filtrate and third residue are obtained simply by adding sodium sulfide to the mother liquor.
Claim 28 depends upon or otherwise require all of the limitations of claim 27 and is also similarly rejected.
Claim 29 recites the limitation “adding aqua regia to the first residue after flotation and enrichment” in line 3. There is insufficient antecedent basis for this limitation in the claim as there is no mention of a “flotation and enrichment step” prior to adding aqua regia.
Claim 29 further recites the “performing a sixth solid-liquid separation on the fifth filtrate added with sodium chloride” in line 6. There is insufficient antecedent basis for this limitation in the claim as there is no mention of a “fifth filtrate added with sodium chloride,” or a step in which sodium chloride is added to the fifth filtrate prior to the sixth solid-liquid separation.
Allowable Subject Matter
Claims 11 – 16, 18, 19, 21, 22, 24, and 25 would be allowable if rewritten in to overcome the objections under 37 CFR 1.71(a) set forth in this Office Action. Additionally, claims 27 – 29 would be allowable if rewritten or amended to overcome the rejections under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action. Claims 17, 20, 23, 26, and 30 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
The closest prior art of record is Jiang, et. al. 2020 (A Novel Value-added Utilization Process for Pyrite Cinder: Selective Recovery. Hydrometallurgy 2020, 193, No. 105314), referred to as Jiang hereinafter, Ying, et. al. 2012 (CN 102491302 A), referred to as Ying hereinafter, and Shen, et. al. 2022 (CN 113955734 A), referred to as Shen hereinafter.
Jiang discloses a method for synthesizing iron phosphate as well as recovering copper and cobalt from pyrite cinder (see Abstract). Jiang further teaches obtaining iron phosphate dihydrate by leaching pyrite with phosphoric acid (see Section 2.2.1. titled “Experimental procedure” on Page 2; also see Fig. 16) and performing a first solid-liquid separation on the slurry from the leaching reaction (Fig. 16 shows that the crude iron phosphate product, depicted as a powder, and the leachate, depicted as a liquid in a flask, are separated after the first leaching reaction, suggesting that a solid-liquid separation takes place after the leaching reaction).
However, Jiang does not teach adding sulfite, or any reducing agent, to the first mixed solution containing the pyrite cinder nor adding a buffer to the mentioned leaching reaction. Furthermore, Jiang does not disclose the pressure the leaching reaction is performed at, suggesting that leaching was done at atmospheric pressure, which is outside the recited range of 0.25 MPa to 0.5 MPa.
Additionally, Jiang fails to disclose or suggest the following limitations of claim 11:
introducing air into the first filtrate and then performing a first stirring reaction on the first filtrate;
performing a second solid-liquid separation on a slurry obtained from the first stirring reaction to obtain a second filtrate and a second residue; and
calcining the second residue to obtain iron phosphate
It is noted that while Jiang teaches a second solid-liquid separation (Fig. 16 shows that the battery grade iron phosphate product, depicted as a powder, and the residual HF, depicted as a liquid in a flask, are separated after the second leaching reaction, suggesting that a solid-liquid separation takes place after the second leaching reaction with HF), the second solid-liquid separation of Jiang occurs after a different method step. More specifically, Jiang performs a second solid-liquid separation after leaching the crude iron phosphate with hydrofluoric acid, which serves as a purification step (see the third conclusion statement on the bottom of Page 10). However, the present invention performs a second solid-liquid separation once after introducing air where it is suggested that iron phosphate is first formed, not when it is purified ([0040] of the specification states that leaching is used to obtain a solution with ferrous dihydrogen phosphate while [0010] states that the second residue is calcined to obtain iron phosphate, suggesting that iron phosphate is first generated during the step in which air is introduced). Thus, the second solid-liquid separation of Jiang serves a different purpose than the second solid-liquid separation of the present invention
Ying teaches a method for preparing iron phosphate including introducing air into a solution containing a ferrous salt and phosphate (see Abstract; also see [0040]) and then performing a stirring reaction ([0040] describes stirring after introducing air), preforming a solid-liquid separation ([0041] describes transferring the material in the introduction of air and stirring step), and calcining to obtain iron phosphate (see [0042]).
While Ying teaches adding phosphoric acid, the phosphoric acid is not used as a leaching solvent. Furthermore, while Ying mentions adding a pH adjuster to control and maintain the pH ([0040] describes adding a pH adjuster to control and maintain a constant pH value), the pH adjuster does not include sodium dihydrogen phosphate or disodium hydrogen phosphate ([0046] provides a list of pH adjusters, which excludes sodium dihydrogen phosphate or disodium hydrogen phosphate). Additionally, the pH adjuster in Ying, which is analogous to a buffer, is added during the step in which air is introduced, wherein the buffer of the present invention is added during the leaching reaction.
Shen discloses a method for preparing iron phosphate from mine acid wastewater (see Abstract) comprising of adding a reducing agent (Abstract describes leaching via a reduction reaction), such as a sulfite ([n0014] provides a list of reducing agents which includes sodium metabisulfite; [n0029] in Example 1 describes adding sodium metabisulfite).
While Shen discloses an embodiment where phosphoric acid is added (see [n0031] in Example 1), the phosphoric acid acts as a phosphorous source, not as a leaching solvent (see [n0017]). Additionally, the leaching step is performed with hydrochloric acid or sulfuric acid (see [n0012]), not phosphoric acid. Similarly, while Shen discloses an embodiment where sodium dihydrogen phosphate is added (see [n0037] in Example 2), the sodium dihydrogen phosphate acts as a phosphorous source, not as a buffer (see [n0017]). Furthermore, Shen does not disclose nor suggest using a buffer.
While it is clear that Jiang, Ying, and Shen do not teach all of the limitations of claim 1 individually, the motivation to combine them to make proper prima facie case of obviousness appears to be lacking as well.
While Shen discloses many of the same reagents as the present invention, i.e. sulfite, phosphoric acid, and sodium dihydrogen phosphate, the phosphoric acid and sodium dihydrogen phosphate serve different functionalities in Shen than they do in the present invention.
Additionally, Shen teaches removing metal impurities after reducing the mine acid wastewater, including cobalt and copper (see [n0021]). However, the present invention avoids the removal of all impurities as the present invention seeks to recover both copper and cobalt in subsequent process steps (see claim 27). Therefore, Shen teaches away from the current invention and would not be able to be combined, especially in possibly rejecting claim 27. Furthermore, in the case that Jiang and Ying could feasibly be combined to make a prima facie case of obviousness, the combination of Jiang and Ying would still fail to teach adding a reducing agent or a sulfite to the pyrite cinder without Shen.
However, the case that Jiang and Ying could be combined to make a prima facie case of obviousness is solely hypothetical. Jiang does not provide any motivation or suggestion for including an oxidation step using air and a calcination step to obtain iron phosphate to their method, especially since Jiang demonstrated synthesizing iron phosphate directly from pyrite cinder without performing these additional steps. Therefore, since Jiang and Ying cannot be combined, it necessarily follows that a prima facie case of obviousness still cannot be made.
Therefore, as discussed above, Jiang, Ying, and Shen, do not disclose or suggest, either alone or in combination, all of the limitations of claim 11 and all of its dependent claims, namely 12 – 29. While claim 30 pertains to a preparation method of lithium iron phosphate, not iron phosphate, claim 30 includes all of the process steps of claim 11. Therefore, Jiang, Ying, and Shen, also do not disclose or suggest, either alone or in combination, all of the limitations of claim 30 as they fail to disclose or suggest the process steps of claim 11. Thus, the methods of claim 11 and its dependent claims, as well as claim 30, are found novel and non-obvious over the prior art of record.
As allowable subject matter has been indicated, applicant's reply must either comply with all formal requirements or specifically traverse each requirement not complied with. See 37 CFR 1.111(b) and MPEP § 707.07(a).
Citation of Pertinent Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Loveday, 2008 (The Use of Oxygen in High Pressure Acid Leaching of Nickel Laterites. Minerals Engineering 2008, 21, 533 – 538) teaches the advantages of introducing oxygen during high-pressure acid leaching processes, including reducing acid and energy consumption as well as how the presence of oxygen affects recovering nickel and iron from regolith, specifically laterites.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VIVIAN F CRUM whose telephone number is (571)270-0554. The examiner can normally be reached Monday-Thursday 7:30AM-5:00PM, Friday 7:30AM-4:00PM.
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, Sally Merkling can be reached at (571) 272-6297. 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.
/V.F.C./Examiner, Art Unit 1738
/MICHAEL FORREST/Primary Examiner, Art Unit 1738
Prosecution Insights