Detailed Office Action
Notice of Pre-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 Amendments
The amendment filed on 02/27/2026 has been entered. Claims 1 – 16 remain pending and under examination.
Claim Rejections – U.S.C. §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 9 – 16 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 9 recites the limitation "before the adding of the at least one base metal oxide". There is insufficient antecedent basis for this limitation in the claim. In particular, the limitation is introduced into the claim prior to the introduction of the step of adding at least one base metal oxide. As such, the limitation lacks antecedent basis and moreover, creates a lack of clarity as to whether the base metal oxide is referring to the latter base metal oxide or the initial base metal oxide (i.e., a “base metal and/or a base metal oxide”). The examiner recommends moving said limitation of “wherein, after completion of the reduction smelting, the molten slag has a base metal content reduced to 3.0 mass% or less before the adding of the at least one base metal oxide” to the end of claim 9.
Claims 10 – 16 are rejected by virtue of dependency.
Claim Rejections – U.S.C. §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 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.
Claims 1 – 8 are rejected under 35 U.S.C. 103 as being unpatentable over Nakamura (US2014/0053687, cited in the IDS of 04/18/2022) in view of Yamada (US 8,366,991)
Regarding claim 1, Nakamura teaches a method for recovering PGM [Title]. Nakamura teaches that the method includes:
Combining calcium oxide and silicon oxide (meeting the claimed fluxing agent), an aluminum oxide catalyst containing PGM (meeting the claimed limitation of an object to be treated containing PGM), carbon/cokes (meeting the claimed reducing agent), and copper (interpreted as the base metal of the claimed “base metal and/or base metal oxide”) [0069] in a reduction smelting furnace [0069 – 0071, Fig 5].
Wherein copper oxide is further added after being recycled/recovered from the oxidation step [0075, Fig 5, Fig 2] (interpreted as the base metal oxide of the “at least one base metal oxide”) and the base metal oxide being copper oxide.
As shown in Fig 5, a melt of Cu alloy is formed (interpreted as the reduction furnace metal containing PGM) and a molten slag is formed that contains platinum (Pt) as well as copper [0062, Fig 5]. Wherein the presence of copper and platinum would be in molten form due to the reduction smelting furnace heating and would be expected to at least partially form an alloy, meeting the limitation of a molten slag containing a PGM alloy. This is further evidenced by [0023 – 0024] of the specification which discloses that the molten slag produced in the conventional reduction smelting contains a PGM alloy.
The molten slag is disposed of [Fig 5, Fig 2], meeting the claimed limitation of “extracting the molten slag”.
The copper alloy containing the PGM is placed in an oxidation smelting step, meeting the claimed limitation of transferring the reduction furnace metal containing PGM to an oxidation furnace for oxidative smelting.
Wherein the oxidative smelting of Nakamura forms a copper oxide slag (meeting the claimed base metal oxide slag) and a Cu-PGM alloy that contains an increased concentration of PGM [Fig 5]. The copper oxide slag and Cu-PGM alloy are separated, meeting the claimed limitation of extracting the base metal oxide slag and obtaining a PGM alloy enriched with PGM.
Nakamura teaches that the molten slag attains a content of 3.0 wt% or less of base metal (i.e. copper) prior to discharge being completed [0032].
Nakamura discloses that platinum and copper metal are present in the slag, wherein the formation of a PGM alloy would be expected due to copper and platinum being in molten form and [0023 – 0024] of the specification stating that formation of PGM alloy in the molten slag occurs in conventional reduction smelting (i.e. the reduction smelting disclosed by Nakamura). Nakamura also discloses that the extracted copper oxide is added to the reduction smelting after being recycled/recovered from the oxidation step [0075, Fig 5].
However, Nakamura does not disclose that the addition of the copper oxide is added from the upper part of the furnace to the formed molten slag such that the base metal oxide settles through the slag to recover PGM and combined with the reduction furnace metal.
Yamada teaches an apparatus for the recovery of platinum group metals [Title]. In particular, Yamada disclose a reduction furnace wherein flux components, reducing components, a copper source, and a platinum group element-containing substance are charged into the furnace and smelted [Col 2, line 18 – 26]. Specifically, Yamada discloses that the furnace suitable for this process includes a material charging port [Col 2, line 58 – 65], wherein Fig 1. shows that this port is in the top of the furnace, meeting the claimed limitation of adding base metal oxide from an upper part of the furnace.
Yamada further states that the copper source can be copper oxide and that when it is charged into the furnace it generates molten copper which sinks through the oxide slag and that as it does so, the copper recovers platinum group elements present in the slag [Col 4, line 59 – 67 and Col 5, line 1 – 5], meeting the limitation of adding base metal oxide to the molten slag and allowing it to settle through said slag to recover PGM contained therein and combine with the reduction furnace metal.
It would have been obvious to one of ordinary skill in the art before the effective filing date to have used the reduction furnace of Yamada in the method of Nakamura. Yamada and Nakamura are directed to the recovery of platinum group metals through reduction smelting and oxidation (same field of endeavor) and therefore, an ordinarily skilled artisan would have a reasonable expectation of success in using the reduction furnace of Yamada in the method of Nakamura. The recycled copper oxide disclosed in Nakamura would be added to through upper part using the reduction furnace of Yamada which would result in the copper oxide becoming molten copper metal, sinking through the slag, and recovering PGM present in the molten slag (as disclosed in Yamada), meeting the claimed limitation. An ordinarily skilled artisan would be motivated by this teaching because Yamada’s teaching/furnace would help prevent the valuable PGM from being left behind in the molten slag waste.
While Nakamura in view of Yamada does not expressly disclose the copper oxide/base metal oxide is added after heating/melting (after a slag and reduction metal has been formed) or after attaining a base metal content of 3.0 wt% or less in the molten slag, the selection of any order of performing process steps and/or mixing ingredients is prima facie obvious in the absence of new or unexpected results; In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) and In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930)(MPEP 2144.04 IV C).
In this case, the applicant has not shown that the sequence of addition of the ingredients/components has produced a new or unexpected result over the prior art. As stated in the claim, the addition of base metal oxide allows for it to settle through the molten slag and recover PGM therein. Likewise, Yamada teaches the achievement of the same benefit with copper oxide [Col 4, line 59 – 67 and Col 5, line 1 – 5].
Regarding claim 2, Nakamura in view of Yamada teaches the invention as applied above in claim 1. Nakamura teaches that the total amount of copper oxide introduced is 112.86 kg and the amount of molten slag is 2855 kg [Fig 5]. As such, the amount (in mass%) of copper oxide (i.e. base metal oxide) added with respect to the mass of molten slag is 3.95% (112.86 kg / 2855 kg * 100), which meets the claimed range.
Regarding claims 3 and 5, Nakamura in view of Yamada teaches the invention as applied in claims 1 – 2. Nakamura teaches that in an example [Fig 5, 0069 – 0071], the retention time was 6 hours which meets the claimed range [0070].
Regarding claims 4 and 6 – 8, Nakamura in view of Yamada teaches the invention as applied above in claims 1 – 3 and 5. Nakamura shows that the amount of copper oxide (Cu2O) added is 112.86 kg and the content of total PGM present during the process is 6.693 kg (the total of the Al2O3 catalyst (5 kg) and Pt in Cu2O slag (1.693 kg)) [Fig 5, “second time”]. As such, the maximum amount of PGM that may be present in the slag during smelting (the amount would be decreasing over time) would be 6.693 kg. As such, the mass ratio of base metal oxide to PGM in the molten slag would be 16.86 or more (increasing as PGM was removed from slag), which overlaps with the claimed range.
With regards to the overlapping ranges taught, it would have been obvious to an ordinarily skilled artisan before the effective filing date of the claimed invention to have selected overlapping ranges as disclosed. Selection of overlapping ranges has been held to be a prima facie case of obviousness (See MPEP § 2144.05 I). “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)”
Claims 9 – 10, 12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Yamada (US 8,366,991, cited with the OA of 04/03/25) in view of Engelhard (GB2086941)
Regarding claim 9, Yamada teaches a method for recovering PGM [Title]. Yamada teaches an example [Example 1] which includes:
Combining catalyst containing PGM (meeting the claimed limitation of an object to be treated containing PGM), copper oxide (interpreted as base metal or base metal oxide), a fluxing agent, and a reducing agent of coke [Example 1]. They are combined in a furnace and heated to produced molten metal overlaid with molten slag [Example 1], interpreted as the reduction furnace used for reduction smelting and heating to form a molten slag and reduction furnace metal containing PGM.
Yamada also discloses that the molten slag still contains PGM [Example 1], interpreted as the molten slag with PGM alloy.
Yamada also discloses that the molten slag and molten metal enriched with PGM are separated [Col 8, line 14 – 16], meeting the claimed limitation of extracting molten slag containing PGM alloy
Yamada further describes that while still molten, the molten metal enriched with PGM can be transferred to an oxidizing furnace where a molten state is further enriched with PGM and a molten oxide (of copper oxide) is formed on said surface [Col 8, line 14 25]. Meeting the claimed limitation of transferring the reduction furnace metal containing PGM to an oxidation furnace for oxidative smelting and forming a base metal oxide slag and an oxidation furnace metal further enriched with PGM.
Yamada discloses that the molten oxide layer is discharged [Col 8, line 25 – 28], meeting the claimed limitation of extracting the base metal oxide slag to obtain PGM alloy enriched with PGM.
Yamada describes that the molten slag from the reduction smelting is extracted/separated from the enriched molten metal and that said molten slag contains PGM [Example 1]. Furthermore, multiple PGMs are present in said molten slag and would be expected to form an alloy due to said metals being in molten form and because as described in [0023 – 0024] of the specification, formation of PGM alloy in the molten slag occurs in conventional reduction smelting (i.e. the reduction smelting taught by Yamada).
However, Yamada does not disclose that this extracted/separated molten slag is transferred in its molten form to another reduction furnace wherein it is contacted by at least one base metal oxide to recover PGM alloy contained in the molten slag.
Engelhard teaches a method of recovering valuable metal from low concentrations [title] including platinum group metals [page 2, line 55 – 65] through a dry process of smelting feed material in the presence of a collector and separating the enriched collector from residual material [page 2, line 120 – 130]. The residual material (i.e. slag) is transferred to a second furnace in molten form (meeting the claimed limitation) wherein a collector is added to the slag to form a second enriched collector, which is recovered and recycled back to the first furnace [Fig 1], meeting the claimed limitation of recovered PGM alloy contained in the extracted molten slag. Engelhard discloses that the process has the benefit of extracting valuable metals from the low concentrations [title] and in particular states that the process allows for extraction of low-level residual values of metal from treated slag [page 3, line 30 – 40]. Engelhard also teaches that the feed material that metals are recovered from can be catalyst material [page 1, line 14 – 22; page 2, line 38 – 40].
It would have been obvious to one of ordinary skill in the art before the effective filing date to have applied the teachings/step disclosed by Engelhard of applying an additional smelting step to extracted molten slag produced in the initial/primary reduction smelting step to the method of Yamada in order to collect residual PGM in the slag. Yamada and Engelhard are both directed to the process of recovering PGM from catalyst material through smelting and oxidation (same field of endeavor). Further still, Yamada acknowledges that some PGM remains unrecovered from the extracted slag following reduction and therefore, an ordinarily skilled artisan would have been motivated to apply the teachings of Engelhard, which explicitly disclose recovering residual amounts of valuable metal from slag, to Yamada to minimize lost PGM and would have a reasonable expectation of success in doing so.
Engelhard further teaches that the additional recovery step includes adding more collector [Fig 1] and Yamada teaches that the collector can be copper oxide [Yamada, Example 1], meeting the claimed limitation of adding at least one base metal oxide to the extracted molten slag containing PGM alloy to recover said PGM alloy and the base metal oxide being copper oxide.
Additionally, Yamada teaches that the base metal content (i.e. copper) is 3.0 wt% or less when the slag is removed from the reduction furnace [Col 2, line 26 – 29]. As such, this would be the slag composition when transferred to the second smelting furnace as described by Yamada in view of Engelhard and therefore, the composition when the additional collector (i.e. base metal oxide) is added in the additional smelting furnace.
Regarding claim 10, Yamada in view of Engelhard teaches the invention as applied in claim 9. Wherein Yamada discloses that the amount of copper oxide added is 300 kg relative to 1000 kg of substance (i.e. PGM source) (i.e. 30 mass%) which falls within the claimed range [Example 1].
It would have been obvious to one of ordinary skill in the art before the effective filing date to have added the same mass ratio of copper oxide to PGM source material in the second reduction smelting step applied to the extracted molten slag (which becomes the PGM source material in the second smelting furnace as disclosed by Engelhard) to recover the remaining PGM. An ordinarily skilled artisan would have a reasonable expectation of success in achieving predictable results.
Regarding claims 12 and 14, Yamada in view of Engelhard teaches the invention as applied in claims 9 – 10. Yamada teaches that the source material contains 0.12 mass% Pt, 0.045 mass% Pd, and 0.009% Rh and that 1000 kg of source is added with 300 kg of copper oxide [Example 1]. Therefore, the total amount of PGM would be 1.74 kg and the mass ratio of PGM present to copper oxide added would be 172.41 (300 kg/1.74 kg), which falls within the claimed range.
It would have been obvious to one of ordinary skill in the art before the effective filing date to have added the same mass ratio of copper oxide to PGM present in the source material in the second reduction smelting step applied to the extracted molten slag (which becomes the PGM source material in the second smelting furnace as disclosed by Engelhard) to recover the remaining PGM. An ordinarily skilled artisan would have a reasonable expectation of success in achieving predictable results.
Claims 11, 13, and 15 – 16 are rejected under 35 U.S.C. 103 as being unpatentable over Yamada (US 8,366,991, cited with the OA of 04/03/25) in view of Engelhard (GB2086941), as applied to claims 9 – 10 above, in further view of Yamada (US2006/0213323, cited in the IDS of 4/18/22, henceforth referred to as “US ‘323” for clarity)
Regarding claims 11 and 13, Yamada in view of Engelhard teaches the invention as applied in claims 9 – 10. Yamada nor Engelhard disclose a retention time for extracting/recovering PGM.
US ‘323 teaches a method of recovering PGM by combining PGM source material, copper oxide, reducing agent and flux in a furnace [Abstract]. Following this reduction step, the molten material is charged to an oxidizing furnace [0064, 0065]. Prior to the transferring step, US ‘323 teaches that the reduction furnace is heated to a preferred temperature range and maintained at this standing temperature for at least 5 hours, which meets the claimed range, in order to ensure more PGM is recovered to the molten metal prior to the separation of the molten slag and molten metal in the reduction furnace [0051 – 0052].
It would have been obvious to one of ordinary skill in the art before the effective filing date to have applied the standing/retention time disclosed by US ‘323 to both reduction steps of the method of Yamada in view of Engelhard. US ‘323, Yamada, and Engelhard are all in the same field of endeavor of recovering PGM via smelting and oxidation and a person of ordinary skill in the art would have a reasonable expectation of success in applying the reduction smelting time of US ‘323 to the reduction steps of Yamada in view Engelhard. Further still, an ordinarily skilled artisan would be motivated to apply the teachings in order to ensure a higher recovery % of the PGM during each reduction smelting step.
Regarding claims 15 – 16, Yamada in view of Engelhard and US ‘323 teaches the invention as applied in claims 11 and 13. Yamada teaches that the source material contains 0.12 mass% Pt, 0.045 mass% Pd, and 0.009% Rh and that 1000 kg of source is added with 300 kg of copper oxide [Example 1]. Therefore, the total amount of PGM would be 1.74 kg and the mass ratio of PGM present to copper oxide added would be 172.41 (300 kg/1.74 kg), which falls within the claimed range.
It would have been obvious to one of ordinary skill in the art before the effective filing date to have added the same mass ratio of copper oxide to PGM present in the source material in the second reduction smelting step applied to the extracted molten slag (which becomes the PGM source material in the second smelting furnace as disclosed by Engelhard) to recover the remaining PGM. An ordinarily skilled artisan would have a reasonable expectation of success in achieving predictable results.
Response to Arguments
Applicant's arguments filed 02/27/26 have been fully considered but they are not persuasive.
Applicant asserts that the newly presented limitation distinguishes from the prior art of:
Nakamura (US2014/0053687) in view of Yamada (US 8,366,991)
and
Yamada (US 8,366,991) in view of Engelhard (GB2086941)
This is respectfully not found persuasive.
Nakamura teaches that the molten slag attains a content of 3.0 wt% or less of base metal (i.e. copper) prior to discharge being completed [0032]. While Nakamura in view of Yamada does not expressly disclose the copper oxide/base metal oxide is added after heating/melting (after a slag and reduction metal has been formed) and/or after attaining a base metal content of 3.0 wt% or less in the molten slag, the selection of any order of performing process steps and/or mixing ingredients is prima facie obvious in the absence of new or unexpected results; In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946) and In re Gibson, 39 F.2d 975, 5 USPQ 230 (CCPA 1930)(MPEP 2144.04 IV C). In this case, the applicant has not shown that the sequence of addition of the ingredients/components has produced a new or unexpected result over the prior art. As stated in Yamada, the addition of base metal oxide allows for it to settle through the molten slag and recover PGM therein. Likewise, Yamada teaches the achievement of the same benefit with copper oxide [Col 4, line 59 – 67 and Col 5, line 1 – 5].
Additionally, Yamada teaches that the base metal content (i.e. copper) is 3.0 wt% or less when the slag is removed from the reduction furnace [Col 2, line 26 – 29]. As such, this would be the slag composition when transferred to the second smelting furnace as described by Yamada in view of Engelhard and therefore, the composition when the additional collector (i.e. base metal oxide) is contacted to it in the additional smelting furnace.
Applicant argues that Engelhard discloses using collector metal (copper or iron) not metal oxide (copper oxide) (page 7, bottom) and therefore, is different from the claimed invention. The examiner agrees that Engelhard discloses collector metal, not metal oxide. However, the prior art rejection is in view of the teachings of both Yamada and Engelhard.
Yamada expressly teaches that copper oxide can serve as a collector material [Example 1]. Yamada discloses that additional benefit the “[W]hen the material charged into the furnace starts to melt, the metal oxides, particularly the copper oxide in the copper source material, is reduced to metallic copper by the reducing agent (powdery coke), thereby generating molten metallic copper. This molten metallic material is heavier than the molten oxide material (slag) and therefore sinks through the slag to settle at the lower part of the furnace, where it forms a pool 20 of molten metal.” and “As the melt of metallic metal produced by reduction of copper oxide goes down through the slag, it takes in platinum group elements present in the slag. That is, it dissolves them.” [Col 4, line 59 – 67 and Col 5, line 1 – 5].
Therefore, applicant’s arguments are not persuasive because the combination of the prior art reasonably suggests using copper oxide as a collector with coke for recovering PGM and that it is beneficial for recovering PGM present in slag material (i.e., the material discharged to the additional furnace).
Applicant further argues that Engelhard does not teach or suggest adding collector to the molten slag after transferring (page 8).
“The process of the invention may also include maintaining the residual material resulting from the fresh collector metal contacting step in the molten state after separation of it from the enriched fresh collector metal, and repeating on it one or more times the above-described contacting and separating operations with additional fresh collector metal.”
That is, Engelhard makes clear that the residual material/molten slag is contacted with collector one or more times in order to recover additional PGM still within the residual material/molten slag after separating (i.e., transferring to the additional furnace(s)). As such, applicant’s argument that Engelhard does not teach or suggest adding collector to the molten slag after transferring is not found persuasive.
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 Austin M Pollock whose telephone number is (571)272-5602. The examiner can normally be reached M - F (11 - 8 ET).
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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.
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/AUSTIN POLLOCK/Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738
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