DETAILED ACTION
Claims 1-19 are pending and currently under review.
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 5/29/2026 has been entered. Claims 1-19 remain(s) pending in the application.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 6-7, and 19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Higuchi et al. (JP2001107125, machine translation referred to herein) alone or alternatively further in view of either one of Katayama et al. (US 4,198,229) or De Castejon (US 3,912,501).
Regarding claim 1, Higuchi et al. discloses a method of dephosphorization of molten iron [0001]; wherein said method includes steps of blowing hydrogen gas or hydrocarbon gas through the molten iron melt while supplying a top-blown oxygen gas to achieve dephosphorization [0023-0024, 0016, 0041]. Higuchi et al. further teaches that it is well-known to add a flux agent during pretreatment (ie. dephosphorization), which one of ordinary skill would readily understand to be a slag-forming agent because flux agents serve to remove impurities from molten iron through formation of slag [0004].
Higuchi et al. does not expressly teach that the slag is further separated as claimed. However, the examiner submits that final slag separation is a commonly well-known step that would have been obvious to one of ordinary skill because it is common practice to separate slag from a desired molten iron material for further processing. Alternatively, this is also expressly disclosed in the prior art. Katayama et al. discloses that it is known to separate slag and molten metal after dephosphorization to avoid rephosphorization of the metal melt [col.13 ln.25-35]. De Castejon discloses that it is generally known to further refine molten metal by removal of impurities such as phosphorous, wherein a resulting slag and impurity-free molten iron can be further separated to obtain final products as desired [col.8 ln.5-63]. Therefore, it would have been obvious to modify the method of Higuchi et al. by performing a slag separation step after dephosphorization as disclosed by the aforementioned prior art for the above benefits. The examiner notes that slag would naturally be present on a surface of molten iron as claimed.
Regarding claim 6, the aforementioned prior art discloses the method of claim 1 (see previous). Higuchi et al. does not expressly teach a ladle. However, one of ordinary skill would understand that ladles are commonly known and widely utilized vessels for molten iron refining, such that the use of a ladle as claimed is prima facie obvious. Alternatively, Katayama et al. discloses the use of a ladle as a receptacle to handle molten iron materials [col.4 ln.40-45].
Regarding claims 7 and 19, the aforementioned prior art discloses the method of claims 1 and 6 (see previous). The examiner notes that the recitation of “when obtaining molten iron by melting a cold iron source…” is a contingent process limitation which does not have to be performed. See MPEP 2111.04. Accordingly, the limitations of claim 7 do not have to be performed when a cold iron source is not utilized. Nonetheless, De Castejon further teaches an apparatus wherein iron is first melted and separated from slag in a first hearth, followed by delivery of the molten iron to a second hearth wherein composition adjustments (ie. dephosphorization) are made [col.8 ln.15-30]. Therefore, the disclosure of De Castejon meets the limitation of a slag separation step prior to discharge of the molten iron from a first melting furnace (ie. first hearth) into a second vessel (ie. second hearth).
Claim(s) 2 and 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Higuchi et al. (JP2001107125, machine translation referred to herein) alone or in view of others as applied to claim 1 above, and further in view of either one of Berger et al. (US 4,726,839) or Guo (CN106929633, machine translation referred to herein).
Regarding claim 2, the aforementioned prior art discloses the method of claim 1 (see previous). Higuchi et al. does not expressly teach a subsequent step of deoxidation as claimed. However, subsequent deoxidation after dephosphorization would have been obvious in view of the prior art. Berger et al. discloses that it is known to desirably adjust iron melt composition after dephosphorization and slag separation by performing deoxidation by adding killing agents such as Al (ie. deoxidizing agent) [abstract, col.4 ln.45-52]. Therefore, it would have been obvious to one of ordinary skill to modify the method of Higuchi et al. by performing subsequent deoxidation to achieve a desired composition. Alternatively, Guo discloses that it is known to perform deoxidation with aluminum subsequent to dephosphorization and molten iron tapping [0024]. Therefore, it would have been obvious to one of ordinary skill to modify the method of Higuchi et al. by performing subsequent deoxidation to achieve a desired deoxidized composition.
Regarding claim 15, the aforementioned prior art discloses the method of claim 1 (see previous). The examiner notes that the recitation of “when obtaining molten iron by melting a cold iron source…” is a contingent process limitation which does not have to be performed. See MPEP 2111.04. Accordingly, the limitations of claim 7 do not have to be performed when a cold iron source is not utilized. Nonetheless, De Castejon further teaches an apparatus wherein iron is first melted and separated from slag in a first hearth, followed by delivery of the molten iron to a second hearth wherein composition adjustments (ie. dephosphorization) are made [col.8 ln.15-30]. Therefore, the disclosure of De Castejon meets the limitation of a slag separation step prior to discharge of the molten iron from a first melting furnace (ie. first hearth) into a second vessel (ie. second hearth).
Claim(s) 3-5 and 8-19, is/are rejected under 35 U.S.C. 103 as being unpatentable over Higuchi et al. (JP2001107125, machine translation referred to herein) alone or in view of others as applied to claim 1 above, and further in view of Schluter et al. (US 2023/0175087).
Regarding claims 3-5 and 8-14, the aforementioned prior art discloses the method of claims 1-2 (see previous). The aforementioned prior art does not expressly teach a molten iron source or composition as claimed. Schluter et al. discloses that it is known to generate molten iron from direct reduced iron products such that existing tooling can be utilized while obtaining desirable slag phases [0010-0020]. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by utilizing a direct reduced iron product as the molten iron source for the benefit of Schluter et al. above. One of ordinary skill would understand DRI products to be a cold iron source of reduced iron. Schluter et al. further teaches that the DRI products have a carbon content of at least 0.1 weight percent, which overlaps with the claimed range [0010]. See MPEP 2144.05(I).
Regarding claims 15-19, the aforementioned prior art discloses the method of claims 2-6 (see previous). The examiner notes that the recitation of “when obtaining molten iron by melting a cold iron source…” is a contingent process limitation which does not have to be performed. See MPEP 2111.04. Accordingly, the limitations of claim 7 do not have to be performed when a cold iron source is not utilized. Nonetheless, De Castejon further teaches an apparatus wherein iron is first melted and separated from slag in a first hearth, followed by delivery of the molten iron to a second hearth wherein composition adjustments (ie. dephosphorization) are made [col.8 ln.15-30]. Therefore, the disclosure of De Castejon meets the limitation of a slag separation step prior to discharge of the molten iron from a first melting furnace (ie. first hearth) into a second vessel (ie. second hearth).
Claim(s) 6-7 and 15-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Higuchi et al. (JP2001107125, machine translation referred to herein) and others as applied to claim 1 above, and further in view of ASM Handbooks (1998, Melting methods).
Regarding claim 6, the aforementioned prior art discloses the method of claim 1 (see previous). The aforementioned prior art does not expressly teach that the vessel is a ladle. ASM Handbooks discloses that it is well-known to perform molten metal refining in special ladles [p.753, p.755]. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by performing refining in a ladle because it is well-known and commonly utilized as expressly taught by ASM Handbooks.
Regarding claims 7 and 15-19, the aforementioned prior art discloses the method of claims 1-6 (see previous). The aforementioned prior art does not expressly teach a consideration of an initial slag separation step prior to discharge and dephosphorization. ASM Handbooks discloses that it is well known to utilize a cupola, for example, as a bulk melter for melting iron prior to subsequent transfer to a special refining ladle [p.753]; wherein a cupola has a structure as seen in [fig.6] of ASM Handbooks. This figure expressly depicts separate tapholes for molten iron and slag, such that slag separation and subsequent discharge of the molten metal from a cupola to a subsequent refining ladle as taught by ASM Handbooks above would have naturally flowed from the structure depicted by ASM Handbooks.
Response to Arguments
Applicant’s arguments filed 5/29/2026 regarding the previous 103 rejections have been considered but are moot in view of the new grounds of rejection over Higuchi et al. 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 NICHOLAS A WANG whose telephone number is (408)918-7576. The examiner can normally be reached usually M-Th: 7-5.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Jonathan Johnson can be reached at 5712721177. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/NICHOLAS A WANG/Primary Examiner, Art Unit 1734
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