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 28 April 2026 has been entered. Claims 1 and 4 are amended. Accordingly, claims 1-4 remain pending in the application. Applicant’s amendments to the claims have overcome each and every objection and 112(b) rejection previously set forth in the Non-Final Office Action mailed 3 February 2026.
Priority
Acknowledgment is made of applicant's claim for foreign priority based on an application filed in JP on 26 August 2022. It is noted, however, that applicant has not filed a certified copy of the English translation of JP 2022135181 application as required by 37 CFR 1.55.
Information Disclosure Statement
The Information Disclosure Statement filed 25 February 2026 has been considered.
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 1-4 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 1, lines 3-5, recite “preparing a hydrophobic deep eutectic solvent used for leaching a metal element from an ore containing the metal element by bringing the ore containing the metal element into contact with the hydrophobic deep eutectic solvent to leach the metal element”. It is unclear what steps constitute “preparing a hydrophobic deep eutectic solvent”, as the claim recites preparing the hydrophobic deep eutectic solvent…by bringing the ore containing the metal element into contact with the hydrophobic deep eutectic solvent. This limitation is interpreted as requiring preparing a hydrophobic deep eutectic solvent used for leaching a metal element from an ore containing the metal element, bringing the ore containing the metal element into contact with the hydrophobic deep eutectic solvent to leach the metal element…
Claims 2-4 are indefinite as they depend from an indefinite base and fail to cure the deficiencies of the base claim.
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.
Claims 1-3 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN 114645144) in view of Batal (WO 2023191737) and Zhu ("Novel recyclable acidic hydrophobic deep eutectic solvents for highly efficient extraction of calcium dobesilate in water and urine samples") and Siriwardana (CN 110392742).
Regarding Claim 1, Zhang discloses a method for recycling a deep eutectic solvent (DES) [n0023]. Zhang further discloses extracting lithium from a lithium-containing solution using a deep eutectic solvent (DES used for extracting lithium meets the limitation of a DES used for leaching a metal element; [n0009], [n0011]). Zhang further discloses the DES after extraction has a low water solubility [n0023], such that the DES of Zhang meets the limitation of hydrophobic. Zhang further discloses the lithium-loaded deep eutectic solvent and a stripping agent were mixed for stripping, and after stripping equilibrium, phase separation (phase separation meets the limitation of collected the leached metal element from the hydrophobic deep eutectic solvent and collecting the hydrophobic deep eutectic solvent) was performed to obtain a lithium-rich solution and an empty-loaded deep eutectic solvent (empty-loaded DES meets the limitation of a recycled DES; [n0059]), wherein the stripping agent is hydrochloric acid (mixing the lithium-loaded DES and the hydrochloric acid stripping agent meets the limitation of bring the hydrophobic DES and hydrochloric acid into contact with each other to supplement the deep eutectic solvent with hydrogen chloride; [n0060]). Zhang further discloses the empty-loaded deep eutectic solvent obtained after back-extraction can be recycled without generating any waste [n0066].
Zhang further discloses the deep eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor [n0010]. Zhang further discloses preferably, the hydrogen bond donor is selected from at least one of benzoyltrifluoroacetone, thiophenecarboxylic acid trifluoroacetone (thiophenecarboxylic acid trifluoroacetone meets the limitation of a carboxy-group containing compound), dibenzoylmethane, naphthoyltrifluoroacetone, and phenylmethylformylpyrazolone [n0014].
Zhang is silent to leaching the lithium metal from an ore by bringing the ore into contact with the hydrophobic deep eutectic solvent to leach the metal element, and bringing the hydrophobic deep eutectic solvent and hydrochloric acid into contact with each other to supplement the deep eutectic solvent with hydrogen chloride after collecting the leached metal element from the hydrophobic deep eutectic solvent.
Zhang, however, discloses lithium resources are mainly found in lithium-bearing ores [n0002]. Zhang further discloses extracting lithium from a lithium-containing solution using a deep eutectic solvent ([n0009], [n0011]), wherein the lithium-containing solution is the lithium precipitation mother liquor separated after preparing lithium carbonate by precipitation method [n0019], and the main process for producing lithium carbonate from lithium ore includes acid leaching, alkali leaching, and salt phase inversion [n0003].
Batal discloses a method for obtaining Zn and Pb (Zn and Pb meet the limitation of a metal element) from Zn-Pb ores using a deep eutectic solvent, comprising preparing a deep eutectic solvent and subjecting the Zn-Pb ore to deep eutectic solvent leaching (subjecting the Zn-Pb ore to deep eutectic solvent leaching meets the limitation of brining the ore containing the metal element into contact with the hydrophobic deep eutectic solvent to leach the metal element), obtaining Zn-Pb loaded solution, and performing an electrowinning process to obtain the Zn and Pb metals (obtaining Zn and Pb metals meets the limitation of collecting the leached metal element from the deep eutectic solvent; pg. 5, line 32-pg. 6, line 13). Batal further discloses leaching metal from ores, using a DES, reduces acid consumption in the acid leaching process (pg. 5, lines 15-17) and does not require extra process steps for removing metals from leaching solutions (pg. 5, lines 22-24). Batal further discloses Zn and Pb are obtained in metallic form by applying electrolysis to the solution of charged deep eutectic solvents by utilizing the high electrical conductivity of deep eutectic solvents after the leaching process, and the uncharged deep eutectic solvents from which the metals are removed can be reused in the leaching system (pg. 8, lines 22-26).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Batal to leach a metal element from an ore containing the metal element by bringing the ore containing the metal element into contact with the hydrophobic deep eutectic solvent and collecting the leached metal element from the hydrophobic deep eutectic solvent, as the lithium-containing solution of Zhang is derived from ores [n0002]-[n0003], and leaching metals from ores directly, using a DES, reduces acid consumption in the acid leaching process (pg. 5, lines 15-17) and does not require extra process steps for removing metals from leaching solutions (pg. 5, lines 22-24), as recognized by Batal.
Zhang is silent to bringing the hydrophobic deep eutectic solvent into contact with hydrochloric acid after collecting the leached metal element.
Zhu discloses regenerating and reusing DESs using hydrochloric acid to maintain the DES extraction efficiency (pg.6, Col. 2, par. 3; pg. 8, Col. 1, par. 2). Zhu further discloses part of the hydrogen bond between Cl- in N8881Cl and H on the carboxyl group of BrCH2COOH was broken during extraction (pg. 7, Col. 1-2). Zhu further discloses using hydrochloric acid to protonate BrCH2COO- to BrCH2COOH (pg. 8, Col. 1, par. 2), which is the hydrogen bond donor (pg. 5, Col. 1, par. 1), and the Cl- from the hydrochloric acid combined with N8881+ to form N8881Cl (pg. 8, Col. 1, par. 2), which is the hydrogen bond acceptor (pg. 2, Col. 2, par. 3), such that the DES was formed again (pg. 8, Col. 1, par. 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Batal and Zhu wherein after collecting the leached metal element (via the electrolysis of Batal), bringing the hydrophobic deep eutectic solvent into contact with hydrochloric acid to supplement the deep eutectic solvent with hydrogen chloride in order to reform the DES and maintain the DES extraction efficiency, as recognized by Zhu (pg. 6, Col. 2, par. 3; pg. 8, Col. 1, par. 2).
Zhu further discloses using 2 mL of 12 mol/L hydrochloric acid (pg. 6, Col. 2, par. 3; pg. 8, Col. 1, par. 2) and 0.1 g DES (pg. 7, Col. 1, par. 1), wherein the ratio of N8881Cl: BrCH2COOH is 2:1, 1:1, 1:2, 1:3, or 1:4 (pg. 3, Table 1). Therefore, the values/ranges provided in Zhu for the volume of HCl, the concentration of HCl, and the ratio of HBA to HBD, results in an amount of hydrochloric acid used in Zhu which overlaps or, in the alternative, is close to the claimed range of 1 mole or more of hydrogen chloride with respect to 1 mole of the hydrogen bond acceptor such that the range taught by Zhu obviates the claimed range. See MPEP 2144.05 (I).
Alternatively, as the amount of DES extraction efficiency is a variable that can be modified, among others, by adjusting the amount of HCl used in regeneration, the precise amount would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed amount cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the amount of HCl in DES regeneration to obtain the desired DES extraction efficiency, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Zhang is further silent to the hydrogen bond acceptor being a chloride salt.
Siriwardana discloses extraction of rare earth elements (rare earth elements meet the limitation of a metal element) in metallic or alloy form using a deep eutectic solvent [0013]. Siriwardana further discloses rare earth elements exist in ores [0008]. Siriwardana further discloses the hydrogen bond donor is selected from C1-C18 carboxylic acids (carboxylic acids meet the limitation of a carboxy group-containing compound) [0027], and the hydrogen bond acceptor is a salt of the formula Cat+X- [0039], wherein the cation (Cat+) may be a quaternary ammonium cation [0040] and the anion in the salt formula may be a halide, particularly Cl- (quaternary ammonium chloride meets the limitation of a chloride salt; [0053]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Siriwardana to use a DES with a chloride salt hydrogen bond acceptor, because a chloride salt hydrogen bond acceptor is a process parameter well-known in the art of using DES for leaching metal elements.
Regarding Claim 2, Zhu further discloses using 2 mL of 12 mol/L hydrochloric acid (pg. 6, Col. 2, par. 3; pg. 8, Col. 1, par. 2) and 0.1 g DES (pg. 7, Col. 1, par. 1), wherein the ratio of N8881Cl: BrCH2COOH is 2:1, 1:1, 1:2, 1:3, or 1:4 (pg. 3, Table 1). Therefore, the values/ranges provided in Zhu for the volume of HCl, the concentration of HCl, and the ratio of HBA to HBD, results in an amount of hydrochloric acid used in Zhu which overlaps or, in the alternative, is close to the claimed range of 2 moles or more of hydrogen chloride with respect to 1 mole of the hydrogen bond acceptor such that the range taught by Zhu obviates the claimed range. See MPEP 2144.05 (I).
Alternatively, as the amount of DES extraction efficiency is a variable that can be modified, among others, by adjusting the amount of HCl used in regeneration, the precise amount would have been considered a result effective variable by one having ordinary skill in the art at the time the invention was made. As such, without showing unexpected results, the claimed amount cannot be considered critical. Accordingly, one of ordinary skill in the art at the time the invention was made would have optimized, by routine experimentation, the amount of HCl in DES regeneration to obtain the desired DES extraction efficiency, since it has been held that where the general conditions of the claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. (In re Aller, 105 USPQ 223).
Regarding Claim 3, Zhang discloses the deep eutectic solvent comprises a hydrogen bond donor and a hydrogen bond acceptor [n0010]. Zhang further discloses the hydrogen bond donor may be thiophenecarboxylic acid trifluoroacetone (thiophenecarboxylic acid trifluoroacetone meets the limitation of a carboxy-group containing compound) [n0014].
Zhang is silent to the hydrogen bond donor being a fatty acid, and the hydrogen bond acceptor being a quaternary ammonium chloride.
Siriwardana discloses extraction of rare earth elements (rare earth elements meet the limitation of a metal element) in metallic or alloy form using a deep eutectic solvent [0013]. Siriwardana further discloses rare earth elements exist in ores [0008]. Siriwardana further discloses the hydrogen bond donor is selected from C1-C18 carboxylic acids (C12-C18 carboxylic acids are fatty acids) [0027], and the hydrogen bond acceptor is a salt of the formula Cat+X- [0039], wherein the cation (Cat+) may be a quaternary ammonium cation [0040] and the anion in the salt formula may be a halide, particularly Cl- (a salt with a quaternary ammonium cation and chloride anions meets the limitation of a quaternary ammonium chloride; [0053]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Siriwardana to use a DES with a fatty acid hydrogen bond donor and a quaternary ammonium chloride hydrogen bond acceptor, because fatty acid hydrogen bond donors and quaternary ammonium chloride hydrogen bond acceptors are process parameters well-known in the art of using DES for leaching metal elements.
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Zhang (CN 114645144) in view of Batal (WO 2023191737) and Zhu ("Novel recyclable acidic hydrophobic deep eutectic solvents for highly efficient extraction of calcium dobesilate in water and urine samples") and Siriwardana (CN 110392742) and Kujawa (US 2024/0084416).
Regarding Claim 4, Zhang, Batal, Zhu, and Siriwardana teach the elements as described above with regards to claim 1.
Zhang discloses the empty-loaded deep eutectic solvent obtained after back-extraction can be recycled without generating any waste [n0066], such that Zhang meets the limitation of bringing the recycled hydrophobic deep eutectic solvent and the lithium-containing solution into contact with each other.
Zhang further discloses lithium resources are mainly found in lithium-bearing ores [n0002]. Zhang further discloses extracting lithium from a lithium-containing solution using a deep eutectic solvent ([n0009], [n0011]), wherein the lithium-containing solution is the lithium precipitation mother liquor separated after preparing lithium carbonate by precipitation method [n0019], and the main process for producing lithium carbonate from lithium ore includes acid leaching, alkali leaching, and salt phase inversion [n0003].
Zhang is silent to leaching a metal element from ore using the DES.
Batal discloses a method for obtaining Zn and Pb (Zn and Pb meet the limitation of a metal element) from Zn-Pb ores using a deep eutectic solvent, comprising preparing a deep eutectic solvent and subjecting the Zn-Pb ore to deep eutectic solvent leaching (subjecting the Zn-Pb ore to deep eutectic solvent leaching meets the limitation of brining the ore into contact with the recycled hydrophobic deep eutectic solvent to allow the recycled hydrophobic deep eutectic solvent to include leached metal and collecting the hydrophobic deep eutectic solvent including leached metal), obtaining Zn-Pb loaded solution, and performing an electrowinning process to obtain the Zn and Pb metals (obtaining Zn and Pb metals meets the limitation of extracting the leached metal element from the deep eutectic solvent; pg. 5, line 32-pg. 6, line 13). Batal further discloses leaching metal from ores, using a DES, reduces acid consumption in the acid leaching process (pg. 5, lines 15-17) and does not require extra process steps for removing metals from leaching solutions (pg. 5, lines 22-24). Batal further discloses Zn and Pb are obtained in metallic form by applying electrolysis to the solution of charged deep eutectic solvents by utilizing the high electrical conductivity of deep eutectic solvents after the leaching process, and the uncharged deep eutectic solvents from which the metals are removed can be reused in the leaching system (pg. 8, lines 22-26).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Batal to leach a metal element from an ore containing the metal element as the lithium-containing solution of Zhang is derived from ores [n0002]-[n0003], and leaching metals from ores directly, using a DES, reduces acid consumption in the acid leaching process (pg. 5, lines 15-17) and does not require extra process steps for removing metals from leaching solutions (pg. 5, lines 22-24), as recognized by Batal.
Zhang is further silent to the metal element being nickel.
Kujawa discloses recovering one or more metals or salts thereof from rock, ore, waste materials, etc. by leaching comminuted or crushed feed materials with a leach reagent, wherein the metals include lithium, nickel, lead, etc. [0002].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Zhang to incorporate the teachings of Batal and Kujawa to leach nickel from a nickel ore by bringing the recycled hydrophobic deep eutectic solvent and a nickel ore into contact with each other, because Zhang in view of Batal, Zhu, and Siriwardana teach the claimed invention except that lithium, zinc, or lead is used instead of nickel. Kujawa teaches that the lithium, lead, and nickel are equivalent products known in the art of leaching metal elements. Therefore, because the two products were art recognized equivalents at the time the invention was made, one of ordinary skill in the art would have found it obvious to substitute the lithium or lead for the nickel.
Response to Arguments
Applicant’s arguments, see "Remarks", pg. 8, par. 1, filed 28 April 2026, with respect to the rejection(s) of claim(s) 1-4 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Zhang (CN 114645144) and Batal (WO 2023191737) and Zhu ("Novel recyclable acidic hydrophobic deep eutectic solvents for highly efficient extraction of calcium dobesilate in water and urine samples") and Siriwardana (CN 110392742).
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.
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/S.E.S./Examiner, Art Unit 1735
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735
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