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 .
Status of Claims
Claims 1, 3, 5, and 7 are currently amended and Claims 2, 4, 6, and 8-10 are as originally filed.
Information Disclosure Statement
The information disclosure statements (IDS) submitted on 01/22/2026 and 03/23/2026 were filed after the mailing date of the non-final rejection on 11/14/2025. The submissions are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statements are being considered by the examiner.
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 1-10 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.
In Claim 1, the steps as recited are unclear with emphasis added. First, Claim 1 recites “producing an intermediate product containing iron oxide and metallic iron” in lines 4. Next, Claim 1 recites heating “to melt the intermediate product, the iron oxide to the metallic iron in a molten state” in lines 7 and 8. Finally, Claim 1 recites the intermediate product charging process “after the metallic iron is melted inside the melting furnace” in line 26. The last instance of metallic iron reads on being present before the intermediate product is charged and melted. It is not clear if this metallic iron is the same or different from the first two instances of metallic iron.
Claims dependent on any of the rejected claims are likewise rejected under this statute.
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, 5, 7, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over González et al in Iron & Steel Technology in view of Matsukevich et al in Journal of Chemical Technology and Biotechnology and evidenced by Schneeberger et al in Berg-und Hüttenmännishce Monatshefte.
González et al teaches improving yield in an all direct reduced iron (DRI) fed electric arc furnace (EAF). At the start of the heat, residual slag and hot heel are in the furnace as represented in Figure 1 from page 3:
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Slag volume increases during the heat as DRI and fluxes are added. The bigger potential payback is improvement from preventing increases in % FeO slag during melting (page 2). Fluxes are added when the heat commences (page 4). The slag basicity is based on the ratio of CaO/SiO2 (page 2). The ratio of coke to DRI by mass is 1:4 to 1:5 (Figure 1). However, González et al does not teach the electric arc furnace dust treatment process or the ratio of coke to iron oxide contained in the intermediate product as recited in Claim 1.
Matsukevich et al teaches recycling EAF dust as defined by Schneeberger et al via reduction to produce sponge iron and zinc concentrate (pages 3453-3454). Schneeberger et al teaches a composition of electrical arc furnace dust with typical high zinc content (page 2):
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Matsukevich et al teaches the dust is formed into briquettes and reduced (page 3454). After reduction, the degree of Fe metallization is less than 100% (Table 3, page 3455), or 2.5-16.5%. The reduction produces powdered zinc oxide and tableted sponge iron (page 3456) that is used in steelmaking (page 3457). Sponge iron is analogous to direct reduced iron (DRI) in ironmaking.
Regarding the electric arc furnace dust treatment process, 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 recycled EAF dust of Matsukevich et al as evidenced by Schneeberger et al as the source of DRI in González et al, since Matsukevich et al teaches shorter recovery time and higher recovery efficiency (page 3457).
Regarding the ratio of coke to the iron oxide in the intermediate product, Matsukevich et al teaches the sponge/DRI contains 2.5-16.5% iron oxide (see Tables 3 and 5). The ratio of coke to oxides in DRI in González et al based on the range of oxides in Matsukevich et al is 1:4(2.5-16.5%) to 1:5(2.5-16.5%), or 1.21:1 to 10:1, which overlaps the claimed range. In the case where the claimed ranges overlap or lie inside ranges disclosed by the prior art, a prima facie case of obviousness exists because the prior art discloses the utility of the composition over the entire disclosed range. See MPEP § 2144.05.
Regarding Claim 3, González et al teaches a basicity that teaches the claimed range on page 39.
Regarding Claim 5, González et al teaches having different heats (page 37), which reads on at least tapping. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to recover the tapped iron into ingots for use in further metallurgical processes.
Regarding Claim 7, González et al teaches metallization of 91.4% to 94.7% (Figure 6, page 41).
Regarding Claim 10, Matsukevich et al teaches producing sponge iron and zinc concentrate (pages 3453-3454).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over González et al in view of Matsukevich et al as applied to claim 1 above, and further in view of Allain (US 4,252,559).
González et al in view of Matsukevich et al discloses the invention substantially as claimed. However, González et al in view of Matsukevich et al does not teach the diameter of the reducing agent as in Claim 2.
Allain teaches supplying an electric arc furnace with ferrous products and fluxes. Allain teaches a carburizing agent is introduced to bring the carbon content of the bath to a value between 1.7 and 6.7% (abstract). The carburizing agent is between 5 mm and 10 mm (column 4, lines 34-37). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the carbon reducing agent in González et al in view of Matsukevich et al to have the size taught by Allain, since Allain teaches controlling decarburization (column 2, lines 28-31).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over González et al in view of Matsukevich et al as applied to claims 1 and 3 above, and further in view of Allain.
González et al in view of Matsukevich et al discloses the invention substantially as claimed. However, González et al in view of Matsukevich et al does not teach the fluxes as in Claim 4.
Allain is applied as discussed above. Allain teaches fluxes including dolomite are introduced in addition to pre-reduced products (column 4, lines 6-8). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the fluxes in González et al in view of Matsukevich et al to include dolomite, since Allain teaches forming a more fluid slag with desired basicity characteristics (column 4, lines 9 and 10).
Claim 6 is rejected under 35 U.S.C. 103 as being unpatentable over González et al in view of Matsukevich et al as applied to claim 1 above, and further in view of Jepson (US 2004/0017837 A1).
González et al in view of Matsukevich et al discloses the invention substantially as claimed. However, González et al in view of Matsukevich et al does not teach a bag filter process as in Claim 6.
Jepson teaches a fume extraction system coupled with the exhaust outlet of a furnace (abstract), typically an electric arc furnace [0005]. The system includes a baghouse with bag filters [0006]. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include a bag filter process in González et al in view of Matsukevich et al as taught by Jepson, since Jepson teaches improved fume extraction system that is efficient and reliable in extracting fumes and dust from the EAF and ensuring sufficient combustion of gases during a batch melting process, while at the same time minimizing the amount of infiltration air drawn through the EAF at any given time [0012].
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over González et al in view of Matsukevich et al as applied to claim 1 above, and further in view of Celada (US 3,681,049).
González et al in view of Matsukevich et al discloses the invention substantially as claimed. However, González et al in view of Matsukevich et al does not teach the temperature as in Claim 8.
Celada teaches charging an electric arc furnace with sponge iron (column 1, lines 55 and 56). The temperatures of the wall and bath are controlled. When the furnace was initially charged with scrap, the temperature of the bath was 1560 °C. After 50 minutes of continuous charging, the bath temperature was 1515 °C. At the end of the continuous charging the bath temperature was 1510 °C. After charging of sponge iron the refining temperature is 1550 °C (column 5, lines 25-55). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention for the temperature in the EAF in González et al in view of Matsukevich et al to have the range taught by Celada, since Celada teaches protecting the refractory lining of the electric arc steelmaking furnace, prolonging the life of the refractory lining, decreasing the unproductive time required for repairing damaged linings, and decreasing the heat wasted due to heat loss incidental to shutting down the furnace for repairs (column 2, lines 18-27).
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over González et al in view of Matsukevich et al as applied to Claim 1 above, and further in view of Dutta et al in Basic Concepts of Iron and Steel Making.
González et al in view of Matsukevich et al discloses the invention substantially as claimed. However, González et al in view of Matsukevich et al does not teach the types of electric arc furnaces recited in Claim 9.
Dutta et al teaches electric arc furnaces are used in steelmaking (page 404). Dust is produced (page 426). The electric arc furnace can include alternating current (AC-EAF) with three electrodes or direct current (DC-EAF) with one electrode (page 408). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a DC-EAF in the process of González et al in view of Matsukevich et al, since Dutta et al teaches DC-EAF is used for faster melting, refining, and increases efficiency (page 426).
Response to Arguments
Applicant’s arguments with respect to claims 1-10 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
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 Tima M. McGuthry-Banks whose telephone number is (571)272-2744. The examiner can normally be reached Monday through Friday, 7:30 am to 4:00 pm.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Keith D. Hendricks can be reached at (571) 272-1401. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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Tima M. McGuthry-Banks
Primary Examiner
Art Unit 1733
/TIMA M. MCGUTHRY-BANKS/Primary Examiner, Art Unit 1733