DETAILED ACTION
Claims 22-34 and 43-47 are pending and currently under review.
Claims 1-21 and 35-42 are cancelled.
Claims 43-47 are newly added.
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 1/16/2026 has been entered. Claims 22-34 and newly submitted claim(s) 43-47 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) 22-23, 25-29, 32, and 43-44 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto et al. (US 2010/0180723) in view of Cowx (US 5,634,960); or alternatively further in view of Faucher et al. (2016, Recent developments in dry slag granulation: a path to improving safety and sustainability of the metallurgical sector).
Regarding claim 22, Fujimoto et al. discloses a method of producing molten iron having a carbon amount of approximately 3 percent or higher (ie. pig iron) [abstract, 0035]; wherein said method includes the steps of providing a solid reduced iron material (ie. DRI product) having an iron metallization rate of at least 90% with further exemplary embodiments having at least 0.1 weight percent carbon and less than 15 weight percent oxides as claimed corresponding to step i) [abstract, 0023, table1], adding said solid reduced iron material into an arc melting furnace along with a carbonaceous material and oxide flux material (ie. slag former) corresponding to steps ii) to iii) [abstract], smelting the aforementioned mixture to obtain a molten metal phase and slag phase having an adjusted basicity of 0.8 to 2 determined by CaO/SiO2 corresponding to steps iv) to v) [abstract, 0034], and then finally tapping the molten iron corresponding to step vi) [abstract]. The examiner notes that the overlap between the aforementioned parameters of Fujimoto et al. and that as claimed is prima facie obviousness. See MPEP 2144.05(I). The examiner further notes that Fujimoto et al. is silent regarding any addition or formation of MgO, such that MgO would naturally be absent and the basicity formula of Fujimoto et al. reasonably corresponds to the claimed basicity formula. Alternatively, Fujimoto et al. expressly discloses that controlling basicity serves to control fluidity of the slag layer [0034]. In other words, slag basicity is disclosed by the prior art to be a result-effective variable that directly influenced slag fluidity. Therefore, absent concrete evidence to the contrary, it is not inventive to discover the optimum or workable ranges of basicity by routine experimentation when the general conditions of the effects of basicity on slag fluidity are already disclosed in the prior art as shown above. See MPEP 2144.05(II).
Fujimoto et al. does not expressly teach limiting an amount of further added iron and/or carbon to be up to 30 weight percent as claimed. Cowx discloses a method of processing metal, slag formers, and carbonaceous material to form molten iron [abstract], wherein said slag formers of quartzite are included in an amount of 1 to 20 weight percent and carbonaceous material is included in an amount of 5 to 15 weight percent to adjust desirable amounts of silicon and carbon, respectively [col.2 ln.20-45]. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by controlling amounts of slag formers and carbonaceous materials for the aforementioned benefits. The examiner notes that the overlap between the inclusion ranges of Cowx and that as claimed is prima facie obvious. See MPEP 2144.05(I).
Fujimoto et al. does not expressly teach a subsequent step of granulating the slag as claimed. However, one of ordinary skill would recognize that slag granulation is a well-known and commonly utilized process of processing slag which would have been obvious to perform. Alternatively, Faucher et al. discloses that it is commonly known to perform wet or dry granulation of slags in order to handle the slag after processing [p.2-4]. Therefore, it would have been obvious to one of ordinary skill to modify the method of Fujimoto et al. by granulating said slag for the aforementioned benefit as taught by Faucher et al.
Regarding claim 23, the aforementioned prior art discloses the method of claim 22 (see previous). The examiner notes that the aforementioned basicity range of Fujimoto et al. further overlaps with the claimed range. See MPEP 2144.05(I).
Regarding claim 25, the aforementioned prior art discloses the method of claim 22 (see previous). Fujimoto et al. further teaches tapping the slag at 1400 degrees C or higher, which overlaps with the claimed range [0036]. See MPEP 2144.05(I).
Regarding claim 26, the aforementioned prior art discloses the method of claim 22 (see previous). Fujimoto et al. further teaches that the flux materials can be CaO or SiO2 among others [0031].
Regarding claims 27-28, the aforementioned prior art discloses the method of claim 22 (see previous). The examiner notes that the aforementioned inclusions of Cowx further overlaps with the claimed ranges. See MPEP 2144.05(I).
Regarding claims 29 and 43-44, the aforementioned prior art discloses the method of claim 22 (see previous). The examiner notes that granulation is known to be either dry or wet, and so one of ordinary skill would have reasonably envisioned one of the two available, well-known options. See MPEP 2143(I)(E). The examiner further submits that slags are commonly known to be further utilized for cement applications as would have been recognized by one of ordinary skill. Alternatively, Faucher et al. further teaches wet or dry granulation as stated above, wherein wet granulation can be useful for processing slags having desirable cementitious properties [p.3, 8-9]. One of ordinary skill would readily understand that it would be obvious to utilize a slag having desirable cementitious properties for cement production.
Regarding claim 32, the aforementioned prior art discloses the method of claim 22 (see previous). The examiner notes that carburization would naturally occur during the method of Fujimoto et al., wherein Fujimoto et al. already teaches a final desired C amount in the molten iron of at least 3 percent as stated previously. Accordingly, the molten iron formed during the method of Fujimoto et al. corresponding to step iv) would naturally be expected to undergo at least some degree of carburization to have an overlapping C content. See MPEP 2144.05(I).
Claim(s) 24 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto et al. (US 2010/0180723) alone or in view of others as applied to claim 22 above, and further in view of Cheng (2011, Iron-making process and equipment).
Regarding claim 24, the aforementioned prior art discloses the method of claim 22 (see previous). The aforementioned prior art does not expressly teach a slag viscosity as claimed. Cheng discloses that it is desirably to control slag viscosity to be from 0.2 to 0.6 Pa-s to achieve desirable operation of the blast furnace [p.1-2]. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by utilizing the slag viscosity disclosed by Cheng for the aforementioned benefit. The examiner notes that the overlap between the viscosity range of Cheng and that as claimed is prima facie obvious. See MPEP 2144.05(I).
Claim(s) 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto et al. (US 2010/0180723) alone or in view of others as applied to claim 22 above, and further in view of Lin et al. (CN104313214, machine translation referred to herein).
Regarding claim 30, the aforementioned prior art discloses the method of claim 22 (see previous). The aforementioned prior art does not expressly teach automated control of slag former supply as claimed. Lin et al. discloses that it is known to provide automated control to accurately control charging of slag forming flux material (ie. limestone, dolomite, silica, etc.) to achieve precise and successful operations based on quantitative modeling [0004, 0006-0007, 0017-0027]. The examiner notes that determination of a quantity of charging material as a function of process parameters would naturally flow from the quantitative modeling of Lin et al. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by utilizing quantitative modeling control of the smelting process to ensure precise and successful operations as taught by Lin et al.
Claim(s) 31 and 33-34 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto et al. (US 2010/0180723) alone or in view of others as applied to claim 22 above, and further in view of Zhang et al. (CN101565769, machine translation referred to herein).
Regarding claims 31 and 33-34, the aforementioned prior art discloses the method of claim 22 (see previous). The aforementioned prior art does not expressly teach how the reduced iron is supplied as claimed. Zhang et al. discloses a method of charging direct reduced iron to a furnace [0002-0004], wherein said direct reduced iron can be charged in a hot form and under sealed conditions to avoid release of dust and avoid interference with the furnace [0005, 0008]. Zhang et al. further teaches that the direct reduced iron is supplied from a tank and chute apparatus having a double layer casing and cooling means, which one of ordinary skill would understand to be thermally insulated from the furnace and/or surroundings, which meets the claimed features [0018-0019, fig.1]. Zhang et al. further teaches supplying the direct reduced iron to the furnace from the apparatus that is sealed under inert nitrogen by a conveying means [0008-0009, 0019, fig.1]. Therefore, it would have been obvious to one of ordinary skill to modify the method of the aforementioned prior art by utilizing the direct reduced iron storage and conveyance means of Zhang et al. such that direct reduced iron can be conveyed to a furnace under sealed conditions for the aforementioned benefits.
Claim(s) 32 is/are rejected under 35 U.S.C. 103 as being unpatentable over Fujimoto et al. (US 2010/0180723) alone or in view of others as applied to claim 22 above, and further evidenced by Tleugabulov et al. (2018, Carburization and decarburization in iron and steel products).
Regarding claim 32, the aforementioned prior art discloses the method of claim 22 (see previous). The aforementioned prior art does not expressly teach carburization of iron as claimed. However, as evidenced by Tleugabulov et al., it is well known that iron will naturally be carburized in a blast furnace to a C content of about 4.2 to 4.5 weight percent, which falls within the claimed range [p.732].
Allowable Subject Matter
Claim 45 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claims 46-47 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Claim 45 and independent claim 46 are directed to a method as claimed, wherein a slag phase has a composition as claimed. There is no prior art of record that teaches or suggests all of the claimed limitations together.
The closest prior art of record is Fujimoto et al. and others as relied upon above. However, these references do not teach the specific slag composition as claimed. Therefore, there is no prior art of record that teaches or suggests the claimed features together.
Response to Arguments
Applicant's arguments filed 1/16/2026 have been fully considered but they are not persuasive.
Applicant argues that Fujimoto et al. does not teach the slag components to be acidic and basic as claimed. The examiner cannot concur. One of ordinary skill would understand that disclosed slag components (ie. CaO, SiO2, etc.) to inherently be acidic or basic, which meets the claim.
Applicant argues that Fujimoto et al. merely teaches B2 basicity and does not B3 basicity as claimed, such that the claimed range is not obvious over Fujimoto et al. The examiner cannot concur.
Firstly, although applicant alleges that the different basicity designations of B2 and B3 are “fundamentally different chemical systems”, the examiner cannot concur. B2 and B3 merely refer to the basicity formulas shown on p.7 of the remarks filed 1/16/2026, wherein one of ordinary skill would recognize these formulas to merely pertain to different values of basicity corresponding to particular components of a slag composition. In other words, B2 and B3 basicity are not mutually exclusive to different chemical systems as alleged by applicant, but rather just pertain to different degrees of basicity. This is further supported by the disclosure of Cheng et al. which shows that steelmaking slags are known to simultaneously have basicity ranges of B2 from 1 to 1.12 (which falls with the disclosure of Fujimoto et al.) and B3 from 1.2 to 1.4 (which falls with the claimed range) [table 6-15].
Accordingly, as stated previously, Fujimoto et al. does not expressly teach or require an MgO slag component, such that one of ordinary skill would understand that no or minimal MgO is added such that the claimed B3 formula reasonably correlates the disclosed B2 basicity of Fujimoto et al.
Alternatively, the examiner again notes that B2 and B3 basicity merely pertain to different degrees of basicity as measured by controlling slag composition (ie. CaO, MgO, SiO2, etc.). In view of the above teaching of Fujimoto et al. regarding controlling basicity (ie. slag composition), one of ordinary skill would therefore understand that slag composition is a result-effective variable which would have been obvious to one of ordinary skill absent evidence or arguments that the claimed basicity range is critical or significant, which has not been presented.
Applicant argues that Fujimoto et al. does not teach adding further iron and/or carbon and that Cowx only mentions DRI as an optional material, such that the combination is not proper. The examiner cannot concur. Both Fujimoto et al. and Cowx are directed to utilizing DRI feedstock. The mere disclosure of DRI as optional in Cowx has no bearing on the prior art combination absent a specific indication of teaching away, which applicant has not presented.
Applicant then argues that the prior art does not teach granulation for the specific purposes recited in p.8-9 of the remarks. It is not entirely clear to the examiner as to what point applicant is trying to make. The instant claims merely recite a final step of granulation, and said granulation would have been commonly known or alternatively obvious in view of Faucher et al. as expressly explained above. If applicant is arguing that the particular reason for granulation is not disclosed in the prior art, the examiner notes that the fact that the inventor has recognized another advantage which would flow naturally from following the suggestion of the prior art cannot be the basis for patentability when the differences would otherwise be obvious. See Ex parte Obiaya, 227 USPQ 58, 60 (Bd. Pat. App. & Inter. 1985).
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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/NICHOLAS A WANG/Primary Examiner, Art Unit 1734