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 .
Response to Amendment
The amendment filed 4/13/2026 has been entered. New claims 43-45 have been filed. Claims 1-5, 8-13, 17-18, 22-28, 31-34, and 43-45 remain pending in this application. The amendments to claim 24 overcome the objection made in the previous Office action; this objection is therefore withdrawn. The amendments made to claims 13, 26, and 27 overcome the 112 rejections made in the previous Office action regarding claims 13, 26, and 27; these rejections are therefore withdrawn.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-5, 8-13, 17-18, 22-24, 28, and 31-34 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by non-patent literature Doyle and Lapidus, Selective thorium and uranium extraction from monazite: II. Approaches to enhance the removal of radioactive contaminants, 2015, Hydrometallurgy 155 (2015) 161–167, herein referred to as Doyle. Additionally, "Perry's Chemical Engineers' Handbook" by Robert H. Perry, Don Green, Sixth Edition, 1984, publicly available at handymath.com at least since 24 September 2010, is cited with regard to claim 5. The Examiner notes that the previous Office action contained a typographic error in this statement of rejection, and failed to include “-34” after listing 31; the rejections for claims 32, 33, and 34 were however detailed in the body of the Office action.
Regarding claim 1, Doyle discloses a method for extracting one or more rare earth elements from rare earth element source (treatment strategies to improve the ability to selectively remove actinides from monazite, p. 161/C2), comprising
combining the rare earth element source in water with a base at temperature less than or equal to 100°C to produce a first composition (in a pretreatment step, monazite was contacted with 40 mL of 20 wt.% NaOH solution and heated to 80 °C, p. 163/C1, obtaining residues that were rinsed, air-dried and weighed before leaching),
combining the first composition with an electrolyte composition comprising a plurality of cations having a hydration enthalpy less negative than that of rare earth element ions associated with the one or more rare earth elements to be extracted to produce a second composition (leaching solutions were prepared with reagent grade oxalic acid dihydrate, dibasic ammonium citrate or Na4EDTA and ammonium hydroxide, p. 163/C1), and
extracting the rare earth elements from the second composition (the solid samples were digested with aqua regia and also analyzed by ICP-MS for the rare earth and actinide elements, p. 163/C1).
Regarding the hydration enthalpy, it is noted that the instant specification provides values for hydration enthalpy of the ammonium cation at around -300 kJ/mol (-322 kJ/mol, 00158) which is less negative than a hydration enthalpy for rare earth elements to be extracted, which the instant specification defines as generally one order of magnitude more negative (La3+ = -3296 kJ/mol, 00149). Doyle teaches the presence of ammonium in the step (b), therefore Doyle teaches that the composition contains cations having a less negative hydration enthalpy than that of one or more rare earth elements to be extract.
Regarding claim 2, Doyle discloses the composition containing oxalate solution having a pH of 3.3, Figure 5, which anticipates the range of pH from about 3 to about 10 required in the instant claim.
Regarding claim 3, Doyle discloses the use of NaOH, p. 163/C1; this anticipates the alkali metal required in the instant claim.
Regarding claim 4, Doyle discloses NaOH, p. 163/C1.
Regarding claim 5, Doyle discloses that 2 g (−270 + 400 mesh) monazite was contacted with 40 mL of 20 wt.% NaOH solution, p. 163/C1; the volume of NaOH in the solution is determined as 40 mL * 0.2 = 8 g NaOH / a* = 6.8 mL NaOH, where the value of a* = 1.1833 g/mL is taken from "Perry's Chemical Engineers' Handbook" by Robert H. Perry, Don Green, Sixth Edition. 6.8 mL / 40 mL = 0.17 = 17%, which anticipates the instant claimed range of about 5% to about 80% by volume.
Regarding claim 8, the composition disclosed by Doyle contains ammonium as discussed above for claim 1. Doyle further discloses the addition of aluminum sulfate, p. 163/C1.
Regarding claims 9 and 10, Doyle discloses the addition of ferric chloride or aluminum sulfate, p. 163/C1.
Regarding claim 11, Doyle discloses the composition containing reagent grade oxalic acid dihydrate (99%, Sigma Aldrich), dibasic ammonium citrate (98%, J.T. Baker analyzed) or Na4EDTA ((99%, J.T. Baker analyzed) and ammonium hydroxide, the latter to adjust the solution pH. Each of these are known organic chelating agents or complexing agents in the art. Doyle additionally discloses the addition of ferric chloride or aluminum sulfate was added to some tests, p. 163/C1, and chloride and sulfate ions are also known in the art to function as complexing agents.
Regarding claim 12, Doyle discloses oxalic acid, Na4EDTA, ammonium citrate, p. 163/C1, as applied to claim 11 above; this anticipates the phosphoric acid, organic acid, diamine, and polyamine required of the instant claim.
Regarding claim 13, Doyle discloses the electrolyte composition admixed with the rare earth element composition at a pH of 5, Figure 12. This anticipates the range of pH from about 3.5 to about 7.5 required by the instant claim.
Regarding claim 17, Doyle discloses a class of −270 + 400 mesh (37–53 μm) particles, p. 163/C1. This anticipates the range of less than about 100 μm regarding particle size as required by the instant claim.
Regarding claim 18, Doyle discloses that the extraction occurs via leaching as discussed above for claim 1.
Regarding claims 22, 23, and 24, Doyle discloses that the rare earth element source is monazite as discussed above for claim 1. It is noted that monazite is a salt of lanthanide ions and phosphate ions, as defined in the instant specification (00134).
Regarding claim 28, Doyle discloses monazite as discussed above for claim 1; this anticipates the content of Ce, Nd, and La required by the instant claim.
Regarding claim 31, Doyle discloses sonication to disrupt passivating product layers during oxalate leaching, p. 164/C1. This process is used to separate layers to facilitate separation of rare earth-bearing matrix from the source, p. 164/C1-C2, which anticipates the physical separation process to separate the rare earth minerals from the rare earth source required by the instant claim.
Regarding claim 32, Doyle discloses the "monazite matrix," p. 164/C1; this anticipates the mineral comprising of monazite required by the instant claim.
Regarding claim 33, Doyle discloses 40 mL of 20 wt.% NaOH solution, p. 163/C1; this anticipates the range of about 1% to about 50% by volume of the first composition required by the instant claim. Doyle additionally discloses that these compositions are "leaching solutions," p. 163/C1; this anticipates the lixiviant required by the instant claim.
Regarding claim 34, Doyle discloses NaOH as applied to claim 33.
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.
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.
Claims 26-27 are rejected under 35 U.S.C. 103 as being unpatentable over Doyle, as applied to claim 1 above.
Regarding claim 26, Doyle teaches the method as applied to claim 1 above. Doyle does not explicitly teach that the method further includes a step of isolating the rare earth element, and wherein the isolated rare earth element comprises a rare earth element metal ionic compound.
However, Doyle teaches that oxalate precipitates rare earth elements (oxalate solutions form insoluble rare earth oxalates, Introduction, p. 161 col. 1) and teaches the precipitation of rare earths to form the rare earth element metal ionic compound (“rare earth oxalate precipitates,” p. 163 col. 1, Section 4 pp. 2). It would be obvious to one skilled in the art to modify the invention of Doyle with a further step of isolating the rare earth elements from the obtained composition (extraction of light REE in citrate solution, p. 163 col. 2 Section 4.1.2) to obtain the rare earth element metal ionic compound; one would be motivated to do so in order to selectively keep U and Th in solution while removing the rare earth elements as precipitates, as Doyle teaches (“Oxalate solutions were thought to be selective for Th and U because the rare earths in monazite undergo solution-mediated transformation to insoluble oxalates;” “Selective leaching of thorium and uranium from monazite would be desirable;” p. 161 Introduction pp. 1). One skilled in the art would therefore arrive at the claimed invention with reasonable prediction of success.
Regarding claim 27, Doyle teaches the method as applied to claim 1 above. Doyle does not explicitly teach that the method further includes a step of isolating the rare earth element, and wherein the isolated rare earth element comprises a rare earth element salt.
However, Doyle teaches that oxalate precipitates rare earth elements (oxalate solutions form insoluble rare earth oxalates, Introduction, p. 161 col. 1) and teaches the precipitation of rare earths to form the rare earth element salt (“rare earth oxalate precipitates,” p. 163 col. 1, Section 4 pp. 2). It would be obvious to one skilled in the art to modify the invention of Doyle with a further step of isolating the rare earth elements from the obtained composition (extraction of light REE in citrate solution, p. 163 col. 2 Section 4.1.2) to obtain the rare earth element salt; one would be motivated to do so in order to selectively keep U and Th in solution while removing the rare earth elements as precipitates, as Doyle teaches (“Oxalate solutions were thought to be selective for Th and U because the rare earths in monazite undergo solution-mediated transformation to insoluble oxalates;” “Selective leaching of thorium and uranium from monazite would be desirable;” p. 161 Introduction pp. 1). One skilled in the art would therefore arrive at the claimed invention with reasonable prediction of success.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Doyle, as applied above to claim 1, in view of Zhang et al. 2017, CONCENTRATION OF RARE EARTH MINERALS FROM COAL BY FROTH FLOTATION, referred to herein as Zhang.
Regarding claim 25, Doyle discloses a method for extracting one or more rare earth elements from rare earth element source, as discussed previously.
Doyle does not disclose the rare earth element source being derived from fine coal refuse.
However, Zhang discloses obtaining concentrated rare earth minerals (REM) such as monazite (abstract) from the flotation of fine coal refuse (abstract; introduction, pp. 3).
It would be obvious to one skilled in the art before the effective filing date of the claimed invention to modify the method taught by Doyle with the additional step of sourcing the material from fine coal refuse, as taught in Zhang. One would be motivated to do so to obtain high concentrations of rare earth elements, which are easily found in Far East coalfields in Russia, motivation taught by Zhang (introduction, pp. 2).
Claims 43-45 are rejected under 35 U.S.C. 103 as being unpatentable over Doyle, as applied to claim 1 above, and in further view of Abdel-Rehim, An innovative method for processing Egyptian monazite, Hydrometallurgy, Volume 67, Issues 1–3, 2002, Pages 9-17.
Regarding claim 43, Doyle discloses that the pretreatment with NaOH of the monazite results in a residue that has had phosphate removed (p. 166 Section 4.4; p. 167, Conclusions). Doyle does not explicitly teach that the rare earth phosphates are converted to rare earth hydroxides, nor that the first composition comprises rare earth hydroxides.
However, Abdel-Rehim teaches that the same process forms a composition comprising rare earth hydroxides (“hydroxide cake of thorium and lanthanides,” p. 11 Sections 2.2 and 3) by converting the rare earth phosphates into rare earth hydroxides (p. 11 Equation 1). It would be obvious to one skilled in the art that this chemical process must necessarily occur in the process taught by Doyle, since the reactants (NaOH treatment of monazite) are equivalent. Therefore it would be obvious to one skilled in the art that the removal of phosphate as taught by Doyle must necessarily exchange the phosphates for the hydroxides contained in the sodium hydroxide, and result in a first composition comprising rare earth hydroxides.
Regarding claim 44, Doyle and Abdel-Rehim teach the invention as applied to claim 43. Doyle further teaches that the pretreatment with NaOH obtains residues that are subjected to oxalate and citrate leaching (p. 165, last sentence), and that this leaching results in rare earth element extraction from the residue (“subsequent REE extraction from the residue using either oxalate or citrate leaching,” p. 166 col.1 Section 4.4). One of ordinary skill in the art would recognize that the leaching of a solid with a solution (“leaching solutions,” p. 163 pp. 2) would necessarily exchange the cations at the surface of the hydroxide residue, since a reaction between a solid and a solution can occur nowhere else besides at a surface of the solid. Therefore Doyle teaches the limitation of the cations of the electrolyte composition exchanging with the rare earth element ions at a surface of the rare earth hydroxides to release the rare earth element ions into solution.
Regarding claim 45, Doyle and Abdel-Rahim teach the invention as applied to claim 44. Doyle also teaches that the electrolyte composition comprises anions (citrate) that form soluble complexes with the rare earth element ions (“citrate and EDTA ions strongly complex with thorium and uranium ions,” “these ligands also have large stability constants with rare earth ions,” p. 161 col. 2 pp. 2; “with citrate leaching of NaOH-pretreated monazite, 40% of rare earth elements dissolved,” p. 166 Section 4.4; Doyle teaches that more extreme pretreatment yielded “rare earth elements totally dissolved” upon contact with the citrate solution, p. 166-167, Section 4.4 pp. 2). This is interpreted to meet the functional limitation of driving an ion-exchange equilibrium toward dissolution, since the dissolution is taught, and therefore must be the equilibrium of the reaction as Doyle teaches it, having been driven by the solubilities of the rare earth element ions in the citrate solution.
Response to Arguments
Applicant's arguments filed 4/13/2026 have been fully considered but they are not persuasive. Applicant asserts that Doyle does not teach or suggest “combining the first composition with an electrolyte composition comprising a plurality of cations having a hydration enthalpy less negative than that of rare earth element ions associated with the one or more rare earth elements to be extracted to produce a second composition” as recited in amended claim 1. However, Doyle teaches the presence of ammonium ions as discussed above in the 102(a)(1) rejections made regarding claim 1, and the instant specification defines ammonium as having a hydration enthalpy less negative than that of rare earth element ions.
Applicant asserts that Doyle teaches that the rare earth elements form insoluble oxalates that passivate the monazite surfaces. While Doyle does teach this (p. 163 col. 1 Section 4 pp. 2), Doyle expressly teaches that the pretreatment of the monazite with NaOH removes phosphate which allows for the dissolution of rare earth elements upon citrate leaching (p. 166 Section 4.4). Therefore Doyle meets the requirements of the instant claim. This argument is therefore not found persuasive.
Applicant asserts that Zhang does not remedy the deficiencies of Doyle as discussed for claim 1. Applicant’s argument has been considered but is rendered moot by the new grounds for rejection made over the amended limitations of claim 1, which Doyle teaches in the prior art, as discussed above.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Eileen Moudou whose telephone number is (571)272-1768. The examiner can normally be reached M-Th 8 AM - 4 PM EST.
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/Eileen Moudou/Examiner, Art Unit 1738
/MICHAEL FORREST/Primary Examiner, Art Unit 1738
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