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 .
Election/Restrictions
Claim 15 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.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 08/04/2026.
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) 1-3, 5, 10-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN109554549B, hereinafter ‘Deng’, in view of US20150292060A1, hereinafter ‘Laucournet’, and US20210140009A1, hereinafter ‘Elliot’.
Regarding Claim 1, discloses a method of recovering rare earth metals from a scrap material that contains rare earth metal ([0002]), the method comprising the steps of:
(a) forming an oxide by subjecting the scrap material to oxidation roasting; (b) preparing a first filtrate by acid leaching a result of step (a) and filtering a residue; (c) forming a precipitate by adding an oxidizing agent to the first filtrate and adjusting pH; and (d1) preparing a second filtrate by filtering the precipitate formed in step (c) ([0010]: In a first aspect, the present invention provides a method for recovering rare earths from NdFeB scrap via high-temperature, high-pressure leaching, comprising the following steps: S1: subjecting the NdFeB scrap to oxidative roasting; S2: subjecting the roasted NdFeB scrap to high-temperature, high-pressure hydrochloric acid leaching, followed by solid-liquid separation and collection of the liquid phase to obtain a leachate; S3: adding an oxidizing agent to the leachate to oxidize Fe²⁺ ions therein to Fe³⁺ ions; and S4: subjecting the leachate treated in step S3 to impurity removal and purification, followed by filtration and collection of the liquid phase to obtain a rare-earth chloride leachate; [0013]: after addition of the oxidant, the pH is adjusted between 3.5-5; [0014]: the oxidant step S4 produces a precipitate);
wherein a rare earth metal recovery rate is 88 wt % or more based on rare earth metals in the scrap material ([0048]: the rare-earth leaching rate is 97.85%).
Further regarding Claim 1, Deng does not disclose obtaining a rare earth metal leaching solution by acid leaching the precipitate formed in step (c) at a predetermined pH and filtering a residue to prepare a third filtrate, which is then combined with the second filtrate.
Elliot discloses the recovery of rare earth elements from rare earth ores or concentrates containing those elements ([0001]). A person of ordinary skill in the art would have recognized Elliot as analogous the claimed invention, as both references are drawn to the same field of endeavor, the recovery of rare earth metals - a reference is analogous art to the claimed invention if the reference is from the same field of endeavor as the claimed invention, In re Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
Elliot discloses a process for leaching analogous to that of Deng, including the addition of an oxidant to a first filtrate and separating the resulting precipitate to form a second precipitate ([0022]). Further, Elliot discloses, in a step subsequent to such separation, the selective leaching of the resulting rare earth hydroxide precipitate. The selective leaching of rare earth hydroxide precipitate is preferably conducted in two stages, each stage having multiple tanks and each stage using hydrochloric acid diluted to around 10% w/w using leach solution from the first leach stage. Leach solution from the second leach stage is preferably used to re-pulp, leach rare earth hydroxide precipitate, and to precipitate rare earth metal that has been dissolved in the second stage, prior to the first leach stage ([0026]). Such a two-stage process exposes the target rare earth metal to more separation medium in which it is soluble, which would thereby increase the yield of dissolved rare earth metal in the filtrate.
Accordingly, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize the two-step leaching process as taught by Elliot in the process of Deng, thereby acid leaching the precipitate formed in step (c) at a predetermined pH and filtering a residue to prepare a third filtrate. One of ordinary skill in the art would have been motivated to make this modification to increase the exposure of the target metal to more separation medium in which it is soluble, thereby increasing the yield of dissolved rare earth metal in the filtrate.
Regarding Claim 2, Deng as modified above makes obvious the scrap material comprises neodymium, as discussed above.
Regarding Claim 3, Deng as modified above makes obvious grinding the scrap material so that a Dv50 particle size of the scrap material is 75 µm or less ([0051] of Deng: the NdFeB waste was crushed and ground to a particle size of -200 mesh – this means that the size of the ground particles are less than or equal to 74 microns, and therefore the Dv50 of these particles would be less than 75 microns).
Regarding Claim 5, Deng as modified above makes obvious the acid leaching in step (b) is performed using an acid solution comprising one selected from a group consisting of hydrochloric acid, sulfuric acid, nitric acid, and combination thereof ([0010]: the leaching acid is hydrochloric acid).
Regarding Claim 10, Deng as modified above makes obvious the oxidizing agent comprises hydrogen peroxide (Deng, [0012]).
Regarding Claim 11, Deng as modified above makes obvious the pH in step (c) is in a range of 3.2 to 4.2 (Deng, [0013]: after adding the oxidant, the pH is adjusted between 3.5-5 - as set forth in MPEP 2144.05, 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) – as such, the instant claimed range is obvious over the prior art range).
Regarding Claim 12, Deng as modified above makes obvious aerating the first filtrate (Deng, [0069]: While stirring the leachate, introduce oxygen as an oxidizing agent at a flow rate of 15 m³/h for 1.5 hours to completely oxidize the Fe²⁺ present therein – such introduction of oxygen is considered aeration).
Regarding Claim 13, Deng as modified above makes obvious the acid leaching in step (d2) is performed using an acid solution comprising one selected from a group consisting of hydrochloric acid, sulfuric acid, nitric acid, and combination thereof (Elliot, [0018]: selectively leaching the rare earth hydroxide precipitate with hydrochloric acid).
Regarding Claim 14, Deng as modified above makes obvious the acid solution in step (d2) comprises hydrochloric acid and the predetermined pH is 3 to 3.8 (Elliot, [0027]: selective leaching is performed at a pH between 3 and 4, which overlaps with and makes obvious the instant claimed range).
Claim(s) 4, 6-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over CN109554549B, hereinafter ‘Deng’, in view of US20150292060A1, hereinafter ‘Laucournet’, and US20210140009A1, hereinafter ‘Elliot’, and further in view of US20200308670A1, hereinafter ‘Daware’.
Regarding Claims 4 and 6-9, while Deng discloses acid leaching using hydrochloric acid, Deng does not disclose that the oxidation roasting in step (a) is performed at a temperature in a range of 550° C. to 730° C., that said hydrochloric acid has a concentration between 0.7 to 2 M, that the amount of scrap material is 5-15 wt% based on a total acid leaching solution, that the acid leaching temperature is in a range between 45 and 85 °C, or that the acid leaching is performed for 1-5 hours.
Daware discloses a method for separation of rare earth metals from a plurality of secondary sources ([0002]). A person of ordinary skill in the art would have recognized Daware as analogous the claimed invention, as both references are drawn to the same field of endeavor, separation of rare earth metals from other materials comprising the same - a reference is analogous art to the claimed invention if the reference is from the same field of endeavor as the claimed invention, In re Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
Daware discloses acid leaching of magnets containing rare earth metals by a process analogous to that of Deng, including steps of roasting, acid leaching, and oxidant addition to result in a precipitate ([0008]), said magnets containing neodymium ([0027]). Daware discloses variation of leaching conditions, including a range for acid concentration of 0.1-0.5 M, durations between 1-5 hours, and temperatures in a range of 313-353 K, or 40-80 °C ([0031]). Daware also discloses the metal oxides is dissolved by acid leaching in hydrochloric acid having solid to liquid ratio of 10 to 100 g/L ([0030]) – assuming a density of hydrochloric acid of 1.02 kg/L, 10-100 g/L solids to liquids corresponds to about 0.98-9.80 wt% scrap material based on a weight of the total acid leaching solution. Further, Daware discloses roasting conditions for oxidation of the leached material, disclosing performing roasting at a temperature between 650 and 1000 °C ([0029]).
Accordingly, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to utilize acid leaching conditions shown in the art to be suitable for leaching Nd-containing materials, including the ranges for acid concentration, duration, temperature, and leachate/leachant ratio, and additionally roasting conditions including roasting temperature as taught by Daware. The use of such conditions would have predictably yielded selective leaching of Nd from materials containing the same, given their use for such a purpose in the prior art.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to LOGAN LACLAIR whose telephone number is (571)272-1815. The examiner can normally be reached M-F, 9:30-5:30 PST.
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, Anthony Zimmer can be reached at (571) 270-3591. 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.
LOGAN LACLAIR
Examiner
Art Unit 1736
/L.E.L./ Examiner, Art Unit 1736
/ANTHONY J ZIMMER/ Supervisory Patent Examiner, Art Unit 1736
Prosecution Insights