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 .
Election/Restrictions
Claims 21-22 and 25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected Group II, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 12/01/2025.
Applicant's election with traverse of Group I, claims in the reply filed on 12/01/2025 is acknowledged. The traversal is on the grounds that the claimed configuration has a segmented base comprising a plurality of segments that are connected together to allow the base to move along the endless path of the conveyor. This is not found persuasive because Bleifuss et al. (US 20080302211 A1) teaches such a configuration, as Bleifuss teaches a conveyor 24 comprising containers 15/80 (i.e., segments of a segmented base) which receive and support briquettes (Fig. 1, Fig. 4, [0050]), where the segments 15 are placed on the conveyor 24 (Fig. 1, [0043]), and are thus connected together, which allow the base to move along the endless path of the conveyor (Fig. 1, [0119, 0135]). While as Applicant notes, Bleifuss does not disclose the segmented base of the conveyor having a hot face temperature of at least 500 °C when it returns to the feed zone, Bleifuss is taken further in view of Kiesel et al. (US 20120198966 A1), which teaches the use of a shrouded return 30 for heating an endless conveyor (Fig. 1-2, [0030]), where the shrouded return may be heated to about 540-1090 °C [0050], (i.e., the conveyor, and a face of a base of the conveyor, could be heated to 540-1090 °C, which is within the claimed range), where doing so would have been obvious, as doing so would improve energy efficiency in the system as taught by Kiesel [0039].
The requirement is still deemed proper and is therefore made FINAL.
Response to Amendment
The amendment filed 12/01/2025 has been entered. Claims 1-7, 10-19, 21-22, 25, and 27 are pending in this application, of which claims 1-7, 10-19, and 27 are examined herein. Claims 21-22 and 25 are withdrawn. Claims 1, 6, 12, and 21-22 are amended. Claims 4, 8-9, 20, 23-24, and 26 are cancelled. Claim 27 is new.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
Applicant is reminded of MPEP 609.04(a)(III), which states in part that “Each information disclosure statement must further include a concise explanation of the relevance, as it is presently understood by the individual designated in 37 CFR 1.56(c) most knowledgeable about the content of the information listed that is not in the English language.” In the instant case, no English language translation or explanation of the relevance of the JP 2018-505965 A document has been supplied with the IDSs filed 12/31/2024. While the IDS are being considered at this time, subsequent IDS documents are expected to conform to the aforementioned standards.
Claim Interpretation
Regarding the instant claims, the phrase “relatively uniform bed of briquettes” is herein interpreted as:
“a relatively uniform layer of briquettes covering a base of the conveyor and typically having a consistent 'bed' depth, at least length ways, i.e. in the direction of briquette travel within the furnace.” as described at pg. 11 lines 10-14 of the instant specification.
Regarding the instant claims, the phrase “linear hearth furnace” is herein interpreted as: “a furnace that extends horizontally in a straight line” as described at pg. 9 lines 9-15 of the instant specification.
Regarding the instant claims, the phrase “segmented base” is herein interpreted as: any form of base that includes a plurality of segments that are separate or connected together to allow the base to move in an endless path” as described at pg. 9 line 30 – pg. 10 line 1 of the instant specification.
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 1-7, 10-19, and 27 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 1 recites the limitation "briquettes" in lines 4, 9, 12, 13, 14, 15, 18, 21, 25, 27, and 28. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” in each line refer to the same briquettes as in lines 2, 4, 9, 12, 13, 14, 15, 18, 21, 25, and/or 27.
Claim 1 recites the limitation "DRI" in lines 21, 22, and 23. The limitation is indefinite as the lack of an article makes unclear whether “DRI” in each line refers to the same DRI as in lines 1, 21, and/or 22.
Claim 1 recites the limitation "the segmented of the base of the conveyor” in line 26. The limitation is indefinite as it is unclear whether a “segmented of the base of the conveyor” is merely another term for “segmented base of the conveyor”, or if it refers to a different component.
Regarding claims 1 and 12, the phrase "such as" render the claims indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
Claim 1 recites the limitation "the segmented of the base of the conveyor” in line 26. There is insufficient antecedent basis for this limitation in the claim.
Claim 3 recites the limitation "briquettes" in line 3. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” refers to the same briquettes as in parent claim 1, or to different briquettes.
The term “relatively uniform” in claim 2 is a relative term which renders the claim indefinite. The specification does provide a standard for ascertaining the requisite degree of the term “relatively uniform” at pg. 11 lines 1-6 of the instant specification, however the definition discloses “understood herein to mean a relatively uniform layer of briquettes covering a base of the conveyor typically having a consistent ‘bed’ depth”, which are themselves relative terms which are not provided with a standard for what a “relatively uniform layer of briquettes covering a base of the conveyor” comprises or how “typically” a consistent bed depth must be present. Therefore, claim 2 is rendered indefinite as it is unclear how uniform the bed of briquettes on the conveyor base actually is.
Claim 6 recites the limitation “the lower region" in lines 1-2. There is insufficient antecedent basis for this limitation in the claim.
Claim 10 recites the limitation "briquettes" in line 2. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” refers to the same briquettes as in parent claim 1, or to different briquettes.
Regarding claim 10, the phrase "typically" renders the claim indefinite because it is unclear whether the limitations following the phrase are part of the claimed invention. See MPEP § 2173.05(d).
A broad range or limitation together with a narrow range or limitation that falls within the broad range or limitation (in the same claim) may be considered indefinite if the resulting claim does not clearly set forth the metes and bounds of the patent protection desired. See MPEP § 2173.05(c). In the present instance, claim 10 recites the broad recitation “20-45%”, and the claim also recites “30-45%” which is the narrower statement of the range/limitation. The claim is considered indefinite because there is a question or doubt as to whether the feature introduced by such narrower language is (a) merely exemplary of the remainder of the claim, and therefore not required, or (b) a required feature of the claim.
The term “significant” in claim 11 is a relative term which renders the claim indefinite. The term “significant” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention, making unclear how much lignocellulosic component must be present.
Claim 12 recites the limitation "briquettes" in lines 2 and 5. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” in each line refer to the same briquettes as in parent claim 1, or to different briquettes.
Claim 13 recites the limitation "briquettes" in line 2. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” in each line refer to the same briquettes as in parent claim 1, or to different briquettes.
Claim 14 recites the limitation "briquettes" in line 2. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” in each line refer to the same briquettes as in parent claim 1, or to different briquettes.
Claim 16 recites the limitation "briquettes" in line 4. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” in each line refer to the same briquettes as in parent claim 1, or to different briquettes.
Claims 17 and 18 recites the limitation "a plurality of burners" in line 2 of each claim. The limitation is indefinite as it is unclear if claims 17 and 18 are further limiting the “plurality of air or oxygen-enriched air fed burners” of parent claim 1, or describe a different set of burners.
Claim 19 recites the limitation "adjusting the amount of air or oxygen-enriched air fed to each burner… to compensate for variations in combustible gases" in lines 1-3. The limitation is indefinite as it is unclear what adjustments to the amount of air or oxygen-enriched air are performed, what variations exist in the combustible gas, and how the variations and adjustments are actually related (e.g., any adjustment is made for each variation in the combustible gases; the air or oxygen-enriched air amount is adjusted to burn combustible gas in a stoichiometric ratio; or in another ratio; or the adjustments are governed by another mathematical formula).
Claim 27 recites the limitation "briquettes" in line 2. The limitation is indefinite as the lack of an article makes unclear whether “briquettes” refers to the same briquettes as in parent claim 1, or to different briquettes.
Claims dependent upon claims rejected above, either directly or indirectly, are likewise rejected under this statute.
Claim Rejections - 35 USC § 103
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 1-3, 5-7, 10-18, and 27 are rejected under 35 U.S.C. 103 as being unpatentable over Bleifuss et al. (US 20080302211 A1, cited in Office Action dated 10/01/2025) in view of Eisele et al. (US 20070209480 A1, cited in Office Action dated 10/01/2025), Hwang et al. (US 20080087135 A1, cited in Office Action dated 10/01/2025), and Kiesel et al. (US 20120198966 A1).
Regarding claim 1, Bleifuss teaches a method for producing direct reduced iron (DRI) from briquettes of a composite of iron ore fragments and carbonaceous material (Title, Abstract, [0064, 0098]) in a linear hearth furnace (Title, [0040-0041]) including walls formed of refractory material 41 (i.e., a refractory-lined chamber) [0093]. Bleifuss teaches having the following zones along the length of the furnace between an inlet for briquettes of iron ore fragments and carbonaceous material and an outlet for direct reduced iron (Fig. 1, 6B, [0084, 0087]): a feed zone 27 that includes the inlet (Fig. 1, [0042, 0084]), a preheat zone 28 [0042], a final reduction zone 30 [0042] and a discharge zone 22 that includes the outlet [0070]. Bleifuss teaches a container moving apparatus 24 that moves through the zones from the inlet to the outlet (Fig. 1, [0042-0044]) and a container return apparatus 14 that returns to the inlet (Fig. 1, [0044-0088]), where as the apparatuses together move containers 15 in a loop, Bleifuss teaches an endless conveyor as claimed. Bleifuss teaches the conveyor 24/14 comprises containers 15/80 having bases 82 for receiving and supporting briquettes (Fig. 5A-D, [0050-0057]). (i.e., segments of a segmented base) which receive and support briquettes (Fig. 1, Fig. 4, [0050]), where the segments 15 are placed on the conveyor 24/14 (Fig. 1, [0043]), and are thus connected together, which allow the base to move along the endless path of the conveyor (Fig. 1, [0119, 0135]). Bleifuss teaches feeding briquettes onto the base of the conveyor in a charging end 20 (i.e., part of the feed zone) (Fig. 1, [0044]), transporting briquettes on the conveyor through the preheat zone 28 and heating briquettes [0131] and releasing volatiles in carbonaceous in briquettes [0042]. Bleifuss teaches the atmosphere to have a reducing atmosphere [0130], and that movement of gases occurs through the preheat zone 28 [0082], thus one of ordinary skill would expect at least some reducing of iron ore in briquettes in the preheating zone 28. Bleifuss teaches heating including generating heat by burning combustible gases in a top space of the preheat zone 28 via a plurality of air fed burners 38 (Fig. 1, [0079, 0094]). Bleifuss teaches the presence of carbon monoxide in the furnace [0130], which is not contained in natural gas fed to the burners 38 [0094], thus the gases burned would include CO combustible gas generated within the furnace.
Bleifuss teaches transporting heated briquettes on the conveyor from the preheat zone 28 through the final reduction zone 30 [0131], with the system (including final reduction zone 30) having a controlled atmosphere to prevent oxidation (i.e., being an anoxic environment) [0108], and heating briquettes [0060] and reducing iron ore in briquettes and forming DRI [0075]. Bleifuss teaches transporting DRI on the conveyor 24 to the discharge zone 22 at the outlet and discharging processed material (i.e., DRI) from the discharge zone 22 (Fig. 1, [0070]). Bleifuss teaches returning the unloaded containers 15 along container return apparatus 14 (analogous to an unloaded conveyor) from the outlet to the inlet of the furnace (Fig. 1, [0067]). Bleifuss teaches repeating feeding briquettes onto the segmented base of the conveyor [0051, 0118].
Bleifuss does not teach wherein the briquettes comprise biomass.
Eisele teaches production of iron using environmentally-benign renewable or recycled reducing agents (Title), where iron ore and a reductant of biomass material in particulate form is shaped into pellets and placed in a furnace to produce metallic iron directly from ore (Abstract), wherein the biomass comprises carbon [0009, 0042], therefore Eisele and Bleifuss are analogous to the instant application as both are directed to methods of direct reduction of pellets of iron ore and carbonaceous material to metallic iron in a furnace. Eisele teaches the invention has the advantage of allowing renewable and recyclable organics to be used as reducing agents without having to first process the organics to produce charcoal or otherwise prepare them for the smelting process, as biomass can be used in a raw form [0039], and that biomass is a surplus or waste product and thus has low costs [0039]. Eisele teaches the use of biomass material or other organic acts as a binder for the pellets holding them together until the reactions are completed, making it unnecessary to use additional binders such as bentonite clay, where the elimination of separate binders results in less contamination of the product, smaller quantities of slag and simplifies the control of slag properties [0039].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used biomass as the carbonaceous material as taught by Eisele (i.e., to use a composite of iron ore fragments and biomass) in the briquettes of iron ore and carbonaceous material of Bleifuss as doing so would not require pretreatment of the biomass, benefit from lower costs, not require additional binders, and result in less contamination of the product, smaller quantities of slag, and simplify control of slag properties as taught by Eisele.
Bleifuss does not teach supplying electromatic energy into the final reduction zone.
Hwang teaches a microwave heating method for iron oxide reduction (Title), where iron oxides are reduced using microwave heating in a furnace chamber that is sealed against entrance of air and produces combustible gas (Abstract), where reduction may be performed in a linear conveyor furnace [0017] thus Hwang and Bleifuss are analogous to the instant application, as both are directed to methods of reducing iron oxides in linear conveyor furnaces that maintain non-oxidizing atmospheres within. Hwang teaches supplying microwave energy into primary zone 98 A (analogous to a final reduction zone) of a furnace chamber 98 of a linear conveyor furnace 88 (Fig. 10, [0061]), where the microwaves may be supplied in addition to further heating by burners [0063]. Hwang teaches microwave heating is selective, and only heats components of the material that needs to be heated, i.e., to reduce the hematite or magnetite and does not heat non ferrous components of the feed material directly, so that the energy is much more efficiently used and the maximum temperature reached can be much lower [0006], while air injection in conventional heating results in combustion of carbo which may waste useful combustibles and adds to the carbon footprint of the process [0010].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have supplied microwaves to reduce iron oxide in the final reduction zone as taught by Hwang to the process of Bleifuss as doing so would use energy more efficiently, reduce the temperatures the furnace must be able to operate at, and reduce the carbon footprint of the process by reducing the amount of heating performed by the use of burners as taught by Hwang.
Bleifuss teaches charging hot return containers (analogous to a segmented base of the conveyor) back to the feed zone 27 [0042, 0149], which would return heat to the furnace and therefore contribute to heating briquettes. Bleifuss does not teach the base of the conveyor having a hot face temperature of at least 500 °C when it returns to the feed zone and before it is loaded with briquettes.
Kiesel teaches a system and method for making metallic iron with reduced CO2 emissions (Title), where metallic iron nodules (i.e., reduced iron) are produced in a linear hearth furnace (Abstract) with a preheat zone 12 ([0023, 0036], Fig. 1-2), and a conversion zone 13 and a fusion zone 14 where iron is reduced and fused (i.e., a final reduction zone) (Fig. 1-2, [0036]), where the metallic iron is produced from compacts such as briquettes comprising reducible material such as iron ore and reducing carbonaceous material [0068], where the briquettes are conveyed on hearth cars 21 (Fig. 1-2, [0037]), thus Kiesel and Bleifuss are analogous to the instant application as both are directed to methods for producing reduced iron from briquettes of iron ore and carbonaceous material in a furnace with a preheat zone and final reduction zone where the briquettes are transported on a conveyor. Kiesel teaches after passing through the furnace, the conveyor 21 is returned to the transfer table 91 for returning the conveyor to the furnace [0038], where the conveyor is heated or at least the rate of cooling is reduced in shrouded return 30 by flue gas from the final reduction zone 13/14 (Fig. 1-2, [0039]), where as the conveyor is heated or cooling of the conveyor is slowed, the conveyor would retain at least some residual heat from passing through the furnace, which would intrinsically contribute to heating the briquettes when fed onto the conveyor. Kiesel teaches the shrouded return may be heated to about 540-1090 °C [0050], thus the conveyor, and a face of a base of the conveyor, may be heated to 540-1090 °C, which is within the claimed range. Kiesel teaches the use of a shrouded return improves energy efficiency in the system [0039].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have maintained a temperature of 540-1090 °C on the conveyor as it returns to the inlet of the furnace as taught by Kiesel in the process of Bleifuss, as doing so would improve energy efficiency in the system as taught by Kiesel. Doing so would have a reasonable expectation of success, as Bleifuss teaches its conveyor should be cooled to the degree that it may accept agglomerate (Bleifuss: [0060]), and Kiesel teaches the briquettes (i.e., agglomerates) are loaded onto the conveyor maintained at 425-650 °C (Fig. 1-2, [0053, 0077].
Thus, the disclosure of Bleifuss in view of Eisele, Hwang, and Kiesel is held to establish a prima facie case of obviousness over the special technical feature as presently claimed.
Regarding claim 2, Bleifuss teaches placing briquettes 88 on containers 80 of conveyor 24 hat carries a lightweight refractory bed on which the raw material 88 is placed [0050] (Fig. 5 A), forming a relatively uniform bed of briquettes on the conveyor as best can be examined in view of the rejection of claim 3 under 35 USC 112(b).
Regarding claim 3, Kiesel teaches the shrouded return may be heated to about 540-1090 °C [0050], thus the conveyor, and a face of a base of the conveyor, may be heated to 540-1090 °C, so as to recover heat therefrom [0039]. Kiesel teaches a temperature of a face of a base of the conveyor of 540-1090 °C. This overlaps the claimed range of at least 800 °C. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Regarding claim 5, Kiesel teaches returning conveyor 21 to the entry zone 70 (Fig. 1, [0035]) through a thermally-insulated chamber 30 to maintain heat or minimise heat loss in the base of the conveyor between the outlet and the inlet of the furnace [0039, 0050]. As Bleifuss is taken in view of Kiesel, to make the return portion of Bleifuss (conveyor 14) a thermally-insulated chamber, and conveyor 14 is in a lower region of the furnace (Fig. 1, [0023]), Bleifuss in view of Kiesel teaches or suggests all of the limitations of the claim.
Regarding claim 6, Kiesel teaches heating returning conveyor 21 and therefore the base of the conveyor 21 using hot gases from the conversion zone 13 or fusion zone 14 (i.e., from the furnace) (Fig. 1, [0035]). As Bleifuss is taken in view of Kiesel, to make the return portion of Bleifuss (conveyor 14) a thermally-insulated chamber, and conveyor 14 is in a lower region of the furnace, Bleifuss in view of Kiesel teaches or suggests all of the limitations of the claim.
Regarding claim 7, Kiesel teaches heating the base of the conveyor 21 by transferring at least a part of hot gases produced in the final reduction zone to the return conveyor 21 (Fig. 1, [0035]). As Bleifuss is taken in view of Kiesel, to make the return portion of Bleifuss (conveyor 14) a thermally-insulated chamber, and conveyor 14 is the lower region of the furnace (Fig. 1, [0023]), Bleifuss in view of Kiesel teaches or suggests all of the limitations of the claim.
Regarding claim 10, Eisele teaches the biomass comprises moisture (i.e., the material is “wet”) [0034-0035, 0050], and wherein the mass percentage of biomass in briquettes is 20-30% by weight on an as-charged basis (Table 1), which is within the claimed range.
Regarding claim 11, Eisele teaches the biomass may be wood [0031], where wood comprises 70-80% cellulose, and 20-30% lignin [0032], thus Eisele teaches wherein the biomass includes a significant lignocellulosic component as best can be examined in view of the rejection of claim 11 under 35 USC 112(b) above.
Regarding claim 12, Eisele teaches wherein the balance of the composition of briquettes is iron ore fragments ([0024], Table 1), flux [0038], and binder materials added to the mass ([0034, 0050], Table 1).
Regarding claim 13, Bleifuss teaches preheating the briquettes to 1000-2000 °F (538 – 1093 °C) [0130] (i.e., controlling the method so that the bulk temperature of briquettes is at least 500 °C when briquettes leave the preheat zone and pass to the final reduction zone).
Regarding claim 14, Hwang teaches wherein the final reduction zone includes electromagnetic energy heating briquettes to 600-1200 °C [0048]. Bleifuss teaches the preheat zone to be at 538-1093 °C [0130]. Bleifuss in view of Hwang teaches a temperature change of -493 °C to 662 ° going from the preheat zone to the final reduction zone. This overlaps the claimed range of increasing the temperature by at least 250 °C in the final reduction zone. The overlap between the ranges taught in the prior art and recited in the claims creates a prima facie case of obviousness because the prior art indicates substantial utility over the entire range disclosed therein, including that portion of the range which also falls within the claimed range. See MPEP § 2144.05(I).
Regarding claim 15, Bleifuss teaches releasing volatiles in the briquettes in the preheat zone [0042, 0130], wherein the briquettes comprise carbonaceous material (analogous to biomass) [0062]. As Bleifuss does not disclose the further presence of volatiles in the briquettes or releasing of volatiles in subsequent zones, it would be recognized by one of ordinary skill that Bleifuss in view of Eisele results in the release of essentially all of the volatiles in the biomass, teaching releasing at least 90% of volatiles in biomass in the briquettes as a gas in the preheat zone.
Regarding claim 16, Bleifuss teaches the furnace to operate as a counter-current furnace [0079], where an exhaust fan 53 vents gases from the furnace through exit flue 40 ([0079-0080], Fig. 1), where as gas flows from the reducing zone 30 to the preheat zone 28 prior to being withdrawn from the exit flue 40 [0079], Bleifuss intrinsically includes generating a higher pressure of gases in the final reduction zone compared to gas pressure in the preheat zone, thereby causing gases generated in the final reduction zone to flow counter-current to the direction of movement of briquettes on the conveyor through the furnace.
Regarding claims 17 and 18, Bleifuss teaches generating heat in the preheat zone (i.e., during step (b)) by burning combustible gases in a plurality of burners 38 that are spaced apart along the length of the top space of the preheat zone 28 of the furnace (e.g., Fig. 1 and 3) and spaced across the width of the preheat zone 28 of the furnace (e.g., Fig. 2-3).
Regarding claim 27, Bleifuss teaches wherein each segment 15/80 of the segmented base comprises a plate 86 upon which briquettes are received (Fig. 4).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Bleifuss in view of Eisele, Hwang, and Kiesel as applied to claim 2 above, and further in view of Heitmann (US 3663201 A).
Bleifuss teaches both the inlet and outlet of the furnace are fitted with sealed doors that are only opened as required to allow the insertion or ejection of containers from the furnace thereby minimizing infiltration of ambient air therein [0084] and that container moving apparatus 24 is shown generally in FIG. 2 as being sealed using a structural enclosure 91 to represent that the container moving apparatus 24 is a substantially mechanically sealed apparatus such that gases in the zones are retained therein [0083], however Bleifuss does not teach adjusting the amount of air or oxygen-enriched air fed to each burner in step (b) to compensate for variations in combustible gases in the top space of the preheat zone.
Heitmann teaches a process for production of sponge iron (Title), where iron ore admixed with carbonaceous reducing agent is passed through a rotary kiln (i.e., a furnace) countercurrent to a reducing gas stream to direct reduce iron ore (Abstract, claim 1), thus Heitmann and Bleifuss are analogous to the instant application as both are directed to processes for direct reducing iron from iron ore in a furnace using a countercurrent gas stream. Heitmann teaches the total rate of air or other oxygen-containing gas fed to the furnace is selected in dependence on the amount of volatile constituents (i.e., combustible gases) in the coal (analogous to biomass) to maintain at least neutral or preferably reducing conditions (Col. 2 lines 18-22) (i.e., adjusting the amount of air or oxygen-enriched air fed to compensate for variations in combustible gases), which prevent reoxidation of the iron (Col. 2 lines 23-29).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have adjusted the amount of combustion air introduced at the burners of Bleifuss to compensate for variations in combustible gases (which would include combustible gases at the top space of the preheat zone) as taught by Heitmann, as doing so would prevent reoxidation of the reduced iron in the furnace as taught by Heitmann. Doing so would have been further obvious as it would limit the presence of oxygen and maintain a reducing atmosphere in the furnace, which is a goal of Bleifuss.
Double Patenting
The nonstatutory double patenting rejection is based on a judicially created doctrine grounded in public policy (a policy reflected in the statute) so as to prevent the unjustified or improper timewise extension of the “right to exclude” granted by a patent and to prevent possible harassment by multiple assignees. A nonstatutory double patenting rejection is appropriate where the conflicting claims are not identical, but at least one examined application claim is not patentably distinct from the reference claim(s) because the examined application claim is either anticipated by, or would have been obvious over, the reference claim(s). See, e.g., In re Berg, 140 F.3d 1428, 46 USPQ2d 1226 (Fed. Cir. 1998); In re Goodman, 11 F.3d 1046, 29 USPQ2d 2010 (Fed. Cir. 1993); In re Longi, 759 F.2d 887, 225 USPQ 645 (Fed. Cir. 1985); In re Van Ornum, 686 F.2d 937, 214 USPQ 761 (CCPA 1982); In re Vogel, 422 F.2d 438, 164 USPQ 619 (CCPA 1970); In re Thorington, 418 F.2d 528, 163 USPQ 644 (CCPA 1969).
A timely filed terminal disclaimer in compliance with 37 CFR 1.321(c) or 1.321(d) may be used to overcome an actual or provisional rejection based on nonstatutory double patenting provided the reference application or patent either is shown to be commonly owned with the examined application, or claims an invention made as a result of activities undertaken within the scope of a joint research agreement. See MPEP § 717.02 for applications subject to examination under the first inventor to file provisions of the AIA as explained in MPEP § 2159. See MPEP § 2146 et seq. for applications not subject to examination under the first inventor to file provisions of the AIA . A terminal disclaimer must be signed in compliance with 37 CFR 1.321(b).
The filing of a terminal disclaimer by itself is not a complete reply to a nonstatutory double patenting (NSDP) rejection. A complete reply requires that the terminal disclaimer be accompanied by a reply requesting reconsideration of the prior Office action. Even where the NSDP rejection is provisional the reply must be complete. See MPEP § 804, subsection I.B.1. For a reply to a non-final Office action, see 37 CFR 1.111(a). For a reply to final Office action, see 37 CFR 1.113(c). A request for reconsideration while not provided for in 37 CFR 1.113(c) may be filed after final for consideration. See MPEP §§ 706.07(e) and 714.13.
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Claims 1-2, 10, 12, and 13-16 are provisionally rejected on the ground of nonstatutory double patenting as being unpatentable over claims 1-4, 6, 8-9, 11-15, 18-19, 22-23, and 25 of copending Application No. 18/038,099 (the reference application) in view of Bleifuss et al. (US 20080302211 A1, cited in Office Action dated 10/01/2025).
Although the claims at issue are not identical, they are not patentably distinct from each other because claim 2 of the reference application contains every element of instant claim 1, except for including a refractory-lined chamber, an endless conveyor that is configured to move in an endless path through the zones from the inlet to the outlet and then returns to the inlet, the conveyor having a segmented base for receiving and supporting briquettes, returning the unloaded conveyor from the outlet to the inlet of the furnace, repeating step (a) of feeding briquettes onto the segmented base of the conveyor, and the base of the conveyor having a hot face temperature of at least 500 °C when it returns to the feed zone and before it is loaded with briquettes.
Bleifuss teaches a method for producing direct reduced iron (DRI) from briquettes of a composite of iron ore fragments and carbonaceous material (Title, Abstract, [0064, 0098]) in a linear hearth furnace (Title, [0040-0041]) including walls formed of refractory material 41 (i.e., a refractory-lined chamber) [0093], where doing so would have been obvious to preserve heat in the furnace and improve energy efficiency. Bleifuss teaches a container moving apparatus 24 that moves through the zones from the inlet to the outlet (Fig. 1, [0042-0044]) and a container return apparatus 14 that returns to the inlet (Fig. 1, [0044-0088]), where as the apparatuses together move containers 15 in a loop, Bleifuss teaches an endless conveyor as claimed, where using such a conveyor would’ve been obvious as ‘099 does not specify the type of the conveyor. Bleifuss teaches the conveyor 24/14 comprises containers 15/80 having bases 82 for receiving and supporting briquettes (Fig. 5A-D, [0050-0057]). (i.e., segments of a segmented base) which receive and support briquettes (Fig. 1, Fig. 4, [0050]), where the segments 15 are placed on the conveyor 24/14 (Fig. 1, [0043]), and are thus connected together, which allow the base to move along the endless path of the conveyor (Fig. 1, [0119, 0135]). Bleifuss teaches repeating feeding briquettes onto the segmented base of the conveyor [0051, 0118].
Kiesel teaches a system and method for making metallic iron with reduced CO2 emissions (Title), where metallic iron nodules (i.e., reduced iron) are produced in a linear hearth furnace (Abstract) with a preheat zone 12 ([0023, 0036], Fig. 1-2), and a conversion zone 13 and a fusion zone 14 where iron is reduced and fused (i.e., a final reduction zone) (Fig. 1-2, [0036]), where the metallic iron is produced from compacts such as briquettes comprising reducible material such as iron ore and reducing carbonaceous material [0068], where the briquettes are conveyed on hearth cars 21 (Fig. 1-2, [0037]), thus Kiesel and Bleifuss are analogous to the instant application as both are directed to methods for producing reduced iron from briquettes of iron ore and carbonaceous material in a furnace with a preheat zone and final reduction zone where the briquettes are transported on a conveyor. Kiesel teaches after passing through the furnace, the conveyor 21 is returned to the transfer table 91 for returning the conveyor to the furnace [0038], where the conveyor is heated or at least the rate of cooling is reduced in shrouded return 30 by flue gas from the final reduction zone 13/14 (Fig. 1-2, [0039]), where as the conveyor is heated or cooling of the conveyor is slowed, the conveyor would retain at least some residual heat from passing through the furnace, which would intrinsically contribute to heating the briquettes when fed onto the conveyor. Kiesel teaches the shrouded return may be heated to about 540-1090 °C [0050], thus the conveyor, and a face of a base of the conveyor, may be heated to 540-1090 °C, which is within the claimed range, where adding the shrouded return would have been obvious as doing so improves energy efficiency in the system (Kiesel: [0039]).
Further reference claims 3, 8, 9, and 11-14 contain every element of instant claims 2, 10, 12, and 13-16 respectively, and as such anticipate claims 2, 10, 12, and 13-16 of the instant application.
This is a provisional nonstatutory double patenting rejection.
Conclusion
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733