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 01/13/2026 has been entered. Claims 1-3 and 5-9 remain pending in the application. Claim 4 has been canceled. No new claims have been added. Regarding the 112(a) rejections previously set forth in the Non-Final Rejection mailed 10/16/2025, the Examiner agrees with Applicant’s argument that Fig. 8 provides sufficient written description support per MPEP 2163 II.3(a), as argued by Applicant (remarks, page 5). The 112(a) rejections previously set forth in the Non-Final Rejection mailed 10/16/2025 are withdrawn. However, the specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See Specification section below.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required: the instant specification must recite the claimed “10 to 15 wt.% of sulfuric acid (H2SO4)” of claim 1.
The meaning of every term used in any of the claims should be apparent from the descriptive portion of the specification with clear disclosure as to its import (emphasis added). See MPEP 608.01(o). In this case, the instant specification currently recites “the first circuit stripping process may use 13 to 17 wt.% of sulfuric acid (H2SO4) in the aqueous phase, preferably 14 to 16 wt.% of sulfuric acid (H2SO4) in the aqueous phase” (page 19, emphasis added). The instant specification recites “when the stripping percentage as a function of the sulfuric acid concentration in the first circuit stripping process was given by O/A = 5, no precipitate occurred at the sulfuric acid concentration of 15 wt.% and the stripping percentages for all the elements other than Al were 90% or above” (page 29, emphasis added). The instant specification further recites an effect for 10 wt% for Comparative Example 1 but not for Example 1 (page 29). The instant limitation of 10 to 15 wt% of claim 1 adds a range of 10-13 wt% which is outside of the low endpoint of 13 wt% in the 13-17 wt% range recited by the instant specification in page 19. Furthermore, the textual description of Example 1 of Fig. 8 does not explain the importance of the claimed 10 wt% sulfuric acid. Therefore, the instant specification fails to provide proper antecedent basis for the claimed subject matter.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3 and 7-9 are rejected under 35 U.S.C. 103 as being unpatentable over US 2004/0050212 A1 of Cheng (as cited in prior Office action) in view of WO 2020/061639 A1 of Osten (using its equivalent US 2021/0354997 A1 as its English translation) and further in view of “Impure ions removal from multicomponent leach solution of nickel sulfide concentrates by solvent extraction in impinging stream rotating packed bed” of Chang (as cited in prior Office action, hereinafter NPL’1).
Regarding claims 1-3 and 7-9, Cheng teaches a solvent extraction process for recovering nickel and cobalt from leach solutions (Title and Abstract).
Regarding claim 1, Cheng teaches separation of nickel and cobalt from manganese and other impurities using a leach solution (Example 2, [0107], Fig. 1, 4, and 5, method of Cheng reads on claimed method for manufacturing a nickel/cobalt mixed solution). Cheng teaches two circuits in the extraction process including extraction, scrubbing, and stripping stages (Example 2, [0106]-[0123], Fig. 1, 4, and 5, reads on claimed extraction process, scrubbing process, and stripping process). Cheng teaches this method allows for manufacturing a mixed nickel and cobalt solution ([0095] in Example 2). The recitation “for cathode material” has been given little patentable weight because the recitation occurs in the preamble. A preamble is generally not accorded patentable weight where it merely recites the purpose of a process or the intended use of a structure, and where the body of the claim does not depend on the preamble for completeness but, instead, the process steps or structural limitations are able to stand alone. See In re Hirao, 535 F.2d 67, 190 USPQ 15 (CCPA 1976) and Kropa v. Robie, 187 F.2d 150, 152, 88 USPQ 478, 481 (CCPA 1951). In this case, since the teachings of Cheng apply to any leach solution containing nickel and cobalt, the method of Cheng therefore applies to cathode materials containing nickel and cobalt.
Cheng therefore reads on the limitation of a method for manufacturing a nickel/cobalt mixed solution for cathode material by a two-circuit process of claim 1.
Cheng teaches a first extraction process using an organic phase with an extraction agent (D2EHPA) to extract all zinc, calcium, copper, and manganese from aqueous leach solution and to minimize the extraction of cobalt, nickel, and magnesium (Example 2, [0109], Fig. 4, the aqueous leach solution is applicable to sulfides; the extraction step of Cheng removes impurities other than magnesium and results in a solution that reads on the claimed extracted organic phase). Cheng teaches a first circuit extraction process performed at a pH 3-4.5 ([0043], reads on claimed first extraction agent at a given value of pH).
Cheng therefore reads on the limitation (a) a first circuit extraction process of extracting impurities other than magnesium from a sulfide containing nickel, cobalt and magnesium using a first extraction agent at a given value of pH resulting in an extracted organic phase of claim 1.
Cheng teaches a scrubbing process to recover any cobalt and nickel that was coextracted in the organic phase to an aqueous phase (Example 2, [0115], Fig. 1, reads on the claimed first circuit scrubbing process of stirring the extracted organic phase to recover the nickel and cobalt extracted from the first circuit extraction in an aqueous phase; one of ordinary skill in the art understands scrubbing involves stirring). While Cheng does not explicitly disclose distilled water, one of ordinary skill in the art of metallurgical processes understands the term “aqueous phase” in this context includes purified water such as distilled water. Using tap water for metallurgical processes in an industrial setting would introduce unacceptable levels of contamination and variability to the process. A patent need not teach, and preferably omits, what is well known in the art. See MPEP § 2164.01.
Cheng therefore reads on the limitation (b) a first circuit scrubbing process of stirring the extracted organic phase along with distilled water to recover the nickel and cobalt extracted from the first circuit extraction process in an aqueous phase of claim 1.
Cheng teaches a selective stripping and bulk stripping process for recovering impurities contained in the first extraction agent in an aqueous phase (Example 2, [0117]-[0122], Fig. 1). Cheng teaches that the steps outlined in their method can be conducted in combination with other extraction or precipitation steps to separate certain elements from each other ([0049]). The method of Cheng can therefore be modified to include a single stripping process to match the instant limitation of a first circuit stripping process.
Cheng therefore reads on the limitation (c) a first circuit stripping process of recovering the impurities contained in the first extraction agent in an aqueous phase of claim 1.
Cheng teaches an extraction process with an extraction agent (Versatic 10) separating nickel and cobalt from magnesium ([0079], Fig. 1, this method can be applied to the solution from the first circuit process).
Cheng therefore reads on the limitation (d) a second circuit extraction process of using a second extraction agent for separation of magnesium of the first circuit process and extracting nickel, cobalt and manganese in an organic phase of claim 1.
Cheng teaches a scrubbing process to recover any cobalt and nickel that was coextracted in the organic phase and recover an aqueous solution with the impurities (Example 2, [0115], Fig. 1, the aqueous solution implies the use of water, including distilled water; the method described applies to any scrubbing process and therefore applies to the claimed second circuit scrubbing process and would thereby have magnesium as the impurity recovered).
Cheng therefore reads on the limitation (e) a second circuit scrubbing process of stirring the organic phase from the second circuit extraction process along with distilled water and recovering the magnesium extracted from the second circuit extraction process in an aqueous phase of claim 1.
Cheng teaches a second stripping process to recover nickel and cobalt when using two extraction steps ([0090], Fig. 3, nickel and cobalt recovery can be done by stripping the aqueous phase and would result in a liquid solution with nickel and cobalt). Cheng teaches that the steps outlined in their method can be conducted in combination with other extraction or precipitation steps to separate certain elements from each other ([0049]). The method of Cheng can therefore be modified to include this second stripping step after two extraction circuits of Example 2 ([0106]-[0126], Fig. 1, 4, and 5).
Cheng therefore reads on the limitation (f) a second circuit stripping process of recovering the extracted nickel and cobalt in an aqueous phase and productizing into a mixed liquid form of claim 1.
Cheng teaches performing a first stripping process using sulfuric acid in an aqueous phase ([0039]) with an O/A ratio from 2 to 200 ([0048], the A/O ratio of the stripping stage may be from 1:2 up to 1:200 which corresponds to an O/A ratio of 2-200). The overlap of O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I. Cheng teaches sulfuric acid is preferred due to its low cost and that two stripping steps may be used with increasing concentration of sulfuric acid to strip the solution of impurity elements and recycle the organic phase from the initial extraction step ([0039]).
Cheng therefore reads on the limitation wherein the first circuit stripping process of (c) is performed using sulfuric acid (H2SO4) in an aqueous phase, with an organic/aqueous (O/A) ratio being 4.9 to 5.1 of claim 1.
However, Cheng does not explicitly disclose using 10 to 15 wt.% of sulfuric acid (H2SO4) in an aqueous phase of claim 1 and (d) a second circuit extraction process of saponifying a second extraction agent of claim 1.
Regarding the concentration of sulfuric acid of claim 1, Osten teaches a method including contacting a nickel rich organic phase with an aqueous strip solution of sufficient H2SO4 concentration to extract nickel from the organic phase (Abstract, aqueous strip solution of sufficient H2SO4 concentration reads on claimed sulfuric acid in an aqueous phase). Osten and Cheng are considered analogous art since they are both similarly concerned with extraction of nickel from a cobalt and nickel-containing raffinate (Osten: [0048], [0119]) and are both concerned with solving the problem of stripping a loaded organic phase with sulfuric acid in aqueous solution.
Osten teaches the concentration of the sulphuric acid used to strip nickel from the loaded organic phase is relative to the nickel concentration itself and that the concentration of sulphuric acid used should be high enough to drive the stripping reaction to the right to form the desired product ([0148]). Osten further teaches typically the sulphuric acid strip solution will contain 300-450 g/L H2SO4, and in an alternative embodiment, the strip solution will contain 10-300 g/L H2SO4 ([0148], 10 g/L to 450 g/L is approximately 1-45 wt% H2SO4 as explained hereafter). While Osten teaches sulfuric acid concentration in g/L, one can calculate the sulfuric acid concentration in wt% by dividing the grams of H2SO4 in 1 L of aqueous solution. The Examiner notes that the density of sulfuric acid is approximately 1.84 g/mL and that the density of sulfuric acid solutions ranges from 1 g/mL (1% sulfuric acid solution) to 1.84 g/mL (100% sulfuric acid solution). Since Osten teaches 10-450 g/L sulfuric acid, one of ordinary skill in the art understands the solution has more water than acid and therefore a calculation using an estimated 1 g/mL density is appropriate. Using an approximate of 1000 g for pure water at 25°C for the 1 L of aqueous solution, 10 g/L H2SO4 and 450 g/L are equivalent to 1 wt% and 45 wt% respectively from calculating:
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the method of Cheng, and adjusting and varying the sulfuric acid concentration, such as within the claimed ranges, as taught by Osten, to ensure a high enough sulfuric acid concentration to drive the stripping reaction to effectively strip nickel from the loaded organic phase, as taught by Olsen.
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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation wherein the first circuit stripping process of (c) is performed using 10 to 15 wt.% of sulfuric acid (H2SO4) in an aqueous phase of claim 1.
Regarding the saponifying step of claim 1, NPL’1 teaches extraction of cobalt and nickel from a leach solution using an extraction agent (Abstract), which is a similar solvent extraction process to Cheng. NPL’1 and Cheng are considered analogous art since they are similarly concerned with extracting cobalt and nickel.
NPL’1 teaches that the extraction agent continuously increases the acidity of the aqueous phase and cannot maintain the optimal pH range for metal extraction (Section 3.1.6, page 58). NPL’1 teaches saponifying an extraction agent by adding NaOH solution helps neutralize the pH and therefore promotes good extraction (Section 3.1.6, page 58).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to modify the extraction process of Cheng to include the saponification step of NPL’1 to improve extraction of nickel and cobalt and therefore separation of magnesium by neutralizing the pH as taught by NPL’1.
Modified Cheng therefore reads on the limitation of a second circuit extraction process of saponifying a second extraction agent of claim 1.
Modified Cheng therefore reads on all the limitations of claim 1.
Regarding claim 2, modified Cheng teaches the method of claim 1 as described above.
Cheng teaches a first circuit extraction process performed at a pH 3-4.5 and an O/A ratio from 0.1-10 ([0043]-[0044], A/O ratio in the extraction stage may lie in the range from 10:1 to 1:10 which is equivalent to an O/A ratio of 0.1-10). The overlap of pH and O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation the first circuit extraction process of (a) is performed at pH 3.4 to 3.6, with an organic/aqueous (O/A) ratio being 1.7 to 1.9 of claim 2.
Regarding claim 3, modified Cheng teaches the method of claim 1 as described above.
Cheng teaches a scrubbing process performed at a pH 3-4.5 and an O/A ratio from 5-200 ([0043]-[0044], A/O ratio in the scrubbing stage may lie in the range from 1:5 to 1:200 which is equivalent to an O/A ratio of 5-200). The overlap of pH and O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation the first circuit scrubbing process of (b) is performed at pH 2.9 to 3.1, with an organic/aqueous (O/A) ratio being 4.9 to 5.1 of claim 3.
Regarding claim 7, modified Cheng teaches the method of claim 1 as described above.
Cheng teaches performing a stripping process using sulfuric acid in an aqueous phase ([0039]) with an O/A ratio from 2 to 200 ([0048], the A/O ratio of the stripping stage may be from 1:2 up to 1:200 which is equivalent to an O/A ratio of 2-200). The overlap of O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Cheng teaches sulfuric acid is preferred due to its low cost and that two stripping steps may be used with increasing concentration of sulfuric acid to strip the solution of impurity elements and recycle the organic phase from the initial extraction step ([0039], using two stripping steps reads on the claimed second circuit stripping process). The stripping process of Cheng can therefore be modified to a second circuit stripping process.
Modified Cheng therefore reads on the limitation wherein the second circuit stripping process of (f) is performed using sulfuric acid (H2SO4) in an aqueous phase, with an organic/aqueous (O/A) ratio being 4.9 to 5.1 of claim 7.
However, Cheng does not explicitly disclose wherein the second circuit stripping process of (f) is performed using 25 to 35 wt.% of sulfuric acid (H2SO4) in an aqueous phase of claim 7.
Regarding the concentration of sulfuric acid of claim 7, Osten teaches a method including contacting a nickel rich organic phase with an aqueous strip solution of sufficient H2SO4 concentration to extract nickel from the organic phase (Abstract, aqueous strip solution of sufficient H2SO4 concentration reads on claimed sulfuric acid in an aqueous phase). Osten and Cheng are considered analogous art since they are both similarly concerned with extraction of nickel from a cobalt and nickel-containing raffinate (Osten: [0048], [0119]) and are both concerned with solving the problem of stripping a loaded organic phase with sulfuric acid in aqueous solution.
Osten teaches the concentration of the sulphuric acid used to strip nickel from the loaded organic phase is relative to the nickel concentration itself and that the concentration of sulphuric acid used should be high enough to drive the stripping reaction to the right to form the desired product ([0148]). Osten further teaches typically the sulphuric acid strip solution will contain 300-450 g/L H2SO4, and in an alternative embodiment, the strip solution will contain 10-300 g/L H2SO4 ([0148], 10 g/L to 450 g/L is approximately 1-45 wt% H2SO4 as explained hereafter). While Osten teaches sulfuric acid concentration in g/L, one can calculate the sulfuric acid concentration in wt% by dividing the grams of H2SO4 in 1 L of aqueous solution. The Examiner notes that the density of sulfuric acid is approximately 1.84 g/mL and that the density of sulfuric acid solutions ranges from 1 g/mL (1% sulfuric acid solution) to 1.84 g/mL (100% sulfuric acid solution). Since Osten teaches 10-450 g/L sulfuric acid, one of ordinary skill in the art understands the solution has more water than acid and therefore a calculation using an estimated 1 g/mL density is appropriate. Using an approximate of 1000 g for pure water at 25°C for the 1 L of aqueous solution, 10 g/L H2SO4 and 450 g/L are equivalent to 1 wt% and 45 wt% respectively from calculating:
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It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use the method of Cheng, and adjusting and varying the sulfuric acid concentration, such as within the claimed ranges, as taught by Osten, to ensure a high enough sulfuric acid concentration to drive the stripping reaction to effectively strip nickel from the loaded organic phase, as taught by Olsen.
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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation using 25 to 35 wt.% of sulfuric acid (H2SO4) of claim 7.
Modified Cheng therefore reads on all the limitations of claim 7.
Regarding claim 8, modified Cheng teaches the method of claim 7 as described above.
Cheng teaches maintaining a 10-60°C temperature throughout the extraction circuit ([0046]). Cheng teaches that temperatures higher than 60°C may evaporate and degrade the organic phase ([0046]). The overlap of temperature ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation wherein the second circuit stripping process of (f) is performed at a process temperature of 55 to 65°C of claim 8.
Regarding claim 9, modified Cheng teaches the method of claim 1 as described above.
Cheng teaches a method for separating nickel and cobalt using two extraction agents: an organophosphinic acid and a carboxylic acid ([0022]-[0024]). Cheng teaches using D2EHPA as the organophosphinic acid ([0026]) and versatic acid VA-10 as the carboxylic acid (Example 2, [103], Fig. 1, 4, and 5). Cheng teaches using D2EHPA for extraction first and then versatic acid VA-10 ([0073], Fig. 2) therefore reading on the instant limitation the first extraction agent is bis(2-ethylhexyl)phosphate (D2EHPA, di- 2-ethylhexyl-phosphoric acid), and the second extraction agent is Versatic Acid-10 (VA-10) of claim 9.
Modified Cheng therefore reads on the limitation wherein the first extraction agent is bis(2-ethylhexyl)phosphate (D2EHPA, di-2-thylhexyl-phosphoric acid), and the second extraction agent is Versatic Acid-10 (VA-10) of claim 9.
Claims 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over US 2004/0050212 A1 of Cheng (as cited in prior Office action) in view of WO 2020/061639 A1 of Osten (using its equivalent US 2021/0354997 A1 as its English translation) and “Impure ions removal from multicomponent leach solution of nickel sulfide concentrates by solvent extraction in impinging stream rotating packed bed” of Chang (as cited in prior Office action, hereinafter NPL’1), as applied to claim 1 above, and further in view of CN 108004419 A of Zhao (as cited in prior Office action with reference to its English machine translation).
Regarding claims 5-6, modified Cheng teaches the method of claim 1 as described above.
Regarding the extraction process of claim 5, Cheng teaches an extraction process O/A ratio from 0.1-10 ([0044], A/O ratio in the extraction stage may lie in the range from 10:1 to 1:10 which corresponds to an O/A ratio of 0.1-10; this ratio applies to a second extraction process). The overlap of O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation of the second circuit extraction process of (d) is performed with an organic/aqueous (O/A) ratio being 3.7 to 3.8 of claim 5.
Regarding the scrubbing process of claim 6, Cheng teaches a scrubbing process performed at an O/A ratio from 5-200 ([0043]-[0044], A/O ratio in the scrubbing stage may lie in the range from 1:5 to 1:200 which corresponds to an O/A ratio of 5-200; this ratio applies to a second scrubbing process). The overlap of O/A ratio ranges of the instant claims and Cheng is prima facie obvious. 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); In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997). See MPEP § 2144.05 I.
Modified Cheng therefore reads on the limitation the second circuit scrubbing process of (e) is performed with an organic/aqueous (O/A) ratio being 4.9 to 5.1 of claim 6.
However, modified Cheng does not explicitly disclose wherein the second circuit extraction process of (d) is performed at pH 6.2 to 6.4 of claim 5 and wherein the second circuit scrubbing process of (e) is performed at pH 6.1 to 6.3 of claim 6.
Zhao teaches a nickel and cobalt extraction method to reduce coextraction (Title).
Zhao teaches that using a pH of 4.8-5.8 mixed solution reduces the coextraction of nickel ([0009]). Zhao teaches that pH values above 6 coextracts nickel and cobalt ([0030]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the invention to increase the pH range of modified Cheng slightly above a pH of 6 as taught by Zhao to the pH 6.2 to 6.4 of the second circuit extraction process of claim 5 and the pH 6.1 to 6.3 of the second circuit scrubbing process of (e) of claim 6 to minimize the separation of nickel and cobalt and use pH values that promote their coextraction as taught by Zhao.
Modified Cheng, as further modified by Zhao, therefore reads on all the limitations of claims 5 and 6.
Response to Arguments
Applicant’s arguments, see pages 8-10, filed 01/13/2026, with respect to the rejections of claims 1-3 and 7-9 under 35 U.S.C. 103 have been fully considered and are persuasive. The Examiner agrees that Cheng does not identify a nexus between the parameter and the property being optimized, as argued by Applicant (remarks, end of page 9 and start of page 10). Therefore, the rejection has been withdrawn. However, upon further consideration, a new grounds of rejection is made over US 2004/0050212 A1 of Cheng (as cited in prior Office action) in view of WO 2020/061639 A1 of Osten (using its equivalent US 2021/0354997 A1 as its English translation) and further in view of “Impure ions removal from multicomponent leach solution of nickel sulfide concentrates by solvent extraction in impinging stream rotating packed bed” of Chang (as cited in prior Office action, hereinafter NPL’1). See 35 U.S.C. 103 rejections in this Office action.
Applicant’s arguments with respect to the sulfuric acid range have been considered but are moot because the new ground of rejection relies on Osten teaching the sulfuric acid range and not solely on the prior art of Cheng as previously set forth in the Non-Final Rejection mailed 10/16/2025.
Citation of Pertinent Prior Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
“A new process for cobalt-nickel separation” of Jones is considered relevant to claims 1-3 and 5-9 since it is similarly concerned with extraction methods for nickel-cobalt leach liquors derived from sulphides and optimizes process parameters such as O/A ratios, pH ranges, times, temperatures, number of stages, and extraction agents used.
Conclusion
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/M.A./Examiner, Art Unit 1733
/REBECCA JANSSEN/Primary Examiner, Art Unit 1733
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