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 .
Applicant amended Claims 1, and 5. A written description rejection is presented below.
Continued Examination Under 37 CFR 1.114
Receipt is acknowledged of a request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e) and a submission, filed on 02/09/2026.
Election/Restrictions
Claims 20 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected system, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 04/09/2025.
Information Disclosure Statements
The information disclosure statements (IDS) submitted on 04/30/2025, 05/12/2025, 06/20/2025, 09/10/2025, 12/03/2025, 01/21/2026, and 01/21/2026 have been considered by the examiner.
Response to Amendment
Responsive to communications filed on 02/09/2026, amendments to the claims have been acknowledged.
The rejections over Murray SE 543642 C2 are maintained under new grounds as necessitated by amendment.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claim 5 is rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Claim 5 is not commensurate in scope with what is provided in the instant Specification. While the Specification provides literal support for “a flow that to at least dominant part is a laminar flow at a release point of the reducing gas into the furnace space” e.g. at Page 16, this recitation does not describe a general laminar flow within the system as claimed. The Specification supports the laminar flow of gas at a release point only. The Specification does not provide sufficient written description of the provision of laminar flow within and throughout the furnace chamber, as implied by the claim. The disclosed method does not preclude the turbulent flow of gases within the furnace chamber, and does not sufficiently describe laminar flow throughout the chamber.
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.
Claim 5 is 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 5 recites “the reducing gas is provided in a flow that is, in dominant part, a laminar flow” in Lines 2-3. While the Specification provides literal support for “a flow that to at least dominant part is a laminar flow at a release point of the reducing gas into the furnace space” e.g. at Page 16, there is no redefinition of the term “dominant part,” which renders the Claim indefinite. The parameters of the term “dominant” have not been expressly defined, nor is there sufficient nexus to any specific meaning of what would constitute a “dominant part.” Appropriate correction or explanation is required.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 5 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
In light of Applicant’s Arguments received 02/09/2026, it appears Applicant is attempting to describe in Claim 1 the achievement or result of the use of laminar flow of the gas. If this is the case, then Claim 5 is not further limiting. See also the prior art rejections for Claims 1-19 and 21-22 below, as they would apply to laminar flow.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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 1-19 and 21-22 are rejected under 35 U.S.C. 103 as being unpatentable over Murray SE 543642 C2 in view of Dou et al. CN 107227385 A, and further in view of Green et al. US 20200048724 A1. NPL Hernandez-Gomez et al. is provided as evidence.
Regarding Claim1 and Claim 5, Murray ‘642 teaches a method for producing direct reduced metal material comprising the steps of charging metal material to be reduced into a closed furnace space (Page 2, Translation). Murray ‘642 does not expressly teach providing both heat and an inert gas into the furnace space.
However, Dou et al. ‘385 teaches purging a furnace with nitrogen (meeting the limitation for an inert gas) until a first temperature is reached, and then providing hydrogen reducing gas into the furnace space while inert gas is still present in the furnace space [0038-0039]. Regarding the reducing gas having a lower density than the inert gas at the same pressure, this is a known feature of nitrogen and hydrogen gas that the reducing gas, hydrogen, has a lower density than the inert nitrogen gas at the same pressure, as evidenced by NPL Hernandez-Gomez et al. (Pg. 4311). The reducing gas pushing the inert gas downwards, until the charged metal material is entirely contained in reducing gas, is therefore considered merely a description of a property of gases having different densities and would be expected to result from injecting hydrogen gas into the inert environment.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to purge the furnace space of Murray ‘642 with nitrogen in order to form a non-oxidizing environment and heat the furnace to a first temperature based on the teachings of Dou et al. ‘385 at [0038-0039].
Murray ‘642 teaches providing a heated hydrogen reducing gas to the furnace space at a temperature high enough to cause reduction, meeting the limitation for providing heat to the furnace so as to maintain a second temperature in the charged metal material, in turn causing water vapor to be formed (Page 2, Translation). Murry teaches condensing and collecting the water vapor formed in the reduction gas heating step and evacuating remaining reducing gas from the furnace space after the charged metal material has been reduced (Page 3, Translation).
Murray ‘642 teaches a method for producing direct reduced metal material comprising the steps of charging metal material to be reduced into a closed furnace space (Page 2, Translation) but does not expressly teach providing both heat and an inert gas into the furnace space. However, the actionable method step of providing reducing gas into a closed furnace space while inert gas is still present, is expressly taught by Dou et al. ‘385.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to purge the furnace space of Murray ‘642 with nitrogen in order to form a non-oxidizing environment and heat the furnace to a first temperature based on the teachings of Dou et al. ‘385 at [0038-0039]. Based upon the difference in density between inert gas and reducing gas, a person of ordinary skill in the art at the time of filing the invention would expect the same or similar interactions between gases to result from the action of providing reducing gas while the inert gas is still present in the furnace space.
Regarding the newly amended limitations Murray ‘642 and Dou et al. ‘385 do not expressly teach the laminar flow of reducing gas.
However, Green et al. ‘724 teaches providing “a smooth laminar flow” of reduction gas into a reactor chamber in order to not disrupt the reduction of a particle curtain of reduced metal [0051]. Though the reduced metal in Green et al. ‘724 is in the form of particulate streams referred to as particle curtains, one of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to maintain controlled reduction of metal to flow reducing gas into the chamber of Murray ‘642 laminarly, based on the teachings of Green et al. ‘724.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to provide reducing gas in a flow that to at least dominant part is a laminar flow in order to ensure the complete exposure of charged metal within the furnace to reducing gas as well as reduce turbulence based on the teachings of Green et al. ‘724 at [0051]. See MPEP 2141.01(a) I. “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212. Additionally, it would have been obvious to provide hydrogen reducing gas into the furnace space of Murray ‘642 while inert gas is still present in the furnace space such that a layer of the reducing gas forms over a layer of the inert gas with a boundary between the reducing gas layer and the inert gas layer, and the providing of the reducing gas progressively lowers the boundary between the reducing gas and the inert gas until the boundary is below the charged metal material and the charged metal material is entirely contained in reducing gas during the provision of heat to the furnace space so as to maintain a second temperature in the charged metal material based on the teachings of Dou et al. ‘385 at [0038-0039] and Green et al. ‘724 at [0051]. One of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to maintain controlled reduction of metal to flow reducing gas into the chamber of Murray ‘642 laminarly, based on the teachings of Green et al. ‘724. The hydrogen gas and inert gas would form a boundary as an inherent property of their densities as evidenced by NPL Hernandez-Gomez et al. e.g. at (Pg. 4311).
Murray ‘642 modified by the nitrogen purging method taught in Dou et al. ‘385 and the laminar flow of reducing gas taught in Green et al. ‘724 meets the limitations of the instant Claims.
Regarding Claim 2, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches furnace gases are circulated in a closed loop (Page 16, Translation). Dou et al. ‘385 further teaches purging the entire furnace system with nitrogen (meeting the limitation for inert gas) [0014].
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to circulate inert gas in a closed loop past the charged metal material such that the charged metal is exposed to a non-oxidizing environment based on the teachings of Dou et al. ‘385 at [0014].
Regarding Claim 3, modified Murray ‘642 teaches the limitations set forth above. Notwithstanding the 112(b) rejections above, Murray ‘642 teaches at (Page 5, Translation) an over pressure valve may be adjusted to release gasses within the furnace space in response to predetermined pressure differences.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to evacuate inert gas to a pressure which is lower than the overpressure with the reasonable expectation of forming a useful pressure difference based on the teachings of Murray ‘642 ‘385 at (Pages 5-6, Translation).
Regarding Claim 4, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches providing hydrogen gas at the top part of the furnace space (Page 7, Translation), meeting the limitation for the instant Claim.
Regarding Claim 6, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches the furnace environment is not recirculated (Page 3, Translation), meeting the limitation for the instant Claim.
Regarding Claim 7, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches providing hydrogen gas until a predetermined overpressure has been reached (Page 12, Translation), meeting the limitation of the instant Claim.
Regarding Claim 8 and Claim 9, modified Murray ‘642 teaches the limitations set forth above. Regarding the position of evacuation, it would have been obvious to one having ordinary skill in the art at the time of filing the invention to reposition parts to evacuate reducing gas from a top part of the furnace. Such a change would constitute a rearrangement of parts and/or reversal of parts obvious to one of ordinary skill at the time of filing the invention. See MPEP 2144.04VI A., C.
Further, Dou et al. ‘385 teaches evacuating gases from the top of the reactor. It would have been obvious to one having ordinary skill in the art at the time of filing the invention to evacuate hydrogen from either the top part of the furnace space of Murray ‘642 or a lower part of the furnace space, with the reasonable expectation of performing a useful reduction gas evacuation based on the teachings of Dou et al. ‘385 at (Page 5, Translation).
Regarding Claim 10, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 teaches furnace gases are circulated in a closed loop (Page 16, Translation). Murray further teaches the evacuation of hydrogen gas from within the furnace (Page 3, Translation) and that evacuation may be performed as part of a material cooling sub-step (Page 9, Translation).
It would have been obvious to one having ordinary skill in the art that the evacuation of heated hydrogen gas leaves a cooler inert gas within the furnace of modified Murray ‘642. It would have been obvious to one having ordinary skill in the art at the time of filing the invention to circulate inert gas in a closed loop so as to cool the reduced metal material based on the teachings of Murray ‘642 at (Page 3, Translation), meeting the limitations of the instant Claim.
Regarding Claim 11, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches evacuating an existing atmosphere from the furnace space so as to achieve a gas pressure of at most 0.5 bar, overlapping with the range of the instant claim of less than 1 bar and meeting the limitation of the instant Claim.
See MPEP 2144.05. In cases where 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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding Claim 12, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches providing a caron-containing gas to the furnace space so that the heated and reduced metal material is carburized by carbon-containing gas (Page 5, Translation), meeting the limitation of the instant Claim.
Regarding Claim 13, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches hydrogen gas as a reducing agent (Page 5, Translation), meeting the limitation of the instant Claim.
Regarding Claim 14, modified Murray ‘642 teaches the limitations set forth above. Dou et al. ‘385 teaches purging the furnace with nitrogen [0014], meeting the limitation of the instant Claim for nitrogen as an inert gas.
Regarding Claim 15, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches the reducing gas is preheated in a heat exchanger which is arranged to transfer thermal energy form water evaporated from the charged metal material to the reducing gas (Page 16, Translation), meeting the limitations of the instant Claim.
Regarding Claim 16, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches condensation may take place until pressure and or temperature homogeneity is achieved, meeting the limitations of the instant Claim for no additional reducing gas being required to maintain a predetermined overpressure in the furnace space or no additional heat is required to maintain the second temperature in the furnace space.
It would have been obvious to one having ordinary skill that a timed condensation and collection step achieves a predetermined amount of liquid water having been collected in said condenser, meeting the limitations of the instant Claim.
Regarding Claims 18 and Claim 19, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches its furnace is charged with a material of at most 50 tonnes (Page 4, Translation), overlapping and meeting the limitation of the instant Claims for a material of up to 5 tonnes or up to 10 tonnes.
Condensation may be performed at least 0.25 hours (15 minutes) meeting the limitations of the instant Claims.
See MPEP 2144.05. In cases where 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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding Claim 17, Claim 21 and Claim 22, modified Murray ‘642 teaches the limitations set forth above. Murray ‘642 further teaches an overpressure has an absolute pressure of “at least 2.3 bar, more preferably at least 2.5 bar, or even about 3 bar or more,” meeting the limitations for the instant Claims (Page 11, Translation).
See MPEP 2144.05. In cases where 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); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Response to Arguments
Applicant's arguments filed 02/09/2026 have been fully considered but they are not persuasive.
Applicant argues Dou et al. ‘385 teaches a closed loop and turbulent flow reduction of metal. However, Dou et al. ‘385 teaches at [0047] that reduction gas “hydrogen is then injected into the lock hopper while the CO2 is vented out.” A reference is prior art for all that it teaches and Dou et al. ‘385 renders obvious to one having ordinary skill in the art at the time of filing the invention the purging of nitrogen or other inert gas within a reduction furnace chamber in order to achieve a non-oxiding atmosphere based on its teachings e.g. at [0060]. See MPEP 2141.01(a) I. “[A] reference need not be from the same field of endeavor as the claimed invention in order to be analogous art.” Bigio, 381 F.3d at 1325, 72 USPQ2d at 1212.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to purge the furnace space of Murray ‘642 with nitrogen or other inert gas in order to form a non-oxidizing environment and heat the furnace to a first temperature based on the teachings of Dou et al. ‘385 at [0038-0039]. “[T]he claiming of a new use, new function or unknown property which is inherently present in the prior art does not necessarily make the claim patentable.” In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977). Based upon the difference in density between inert gas and reducing gas, a person of ordinary skill in the art at the time of filing the invention would expect the same or similar interactions between gases to result from the action of providing reducing gas while the inert gas is still present in the furnace space.
Further, as set forth in the 35 U.S.C. 112 (a), (b), and (d) rejections above, the instant Specification does not appear to support the laminar flow of gas within the furnace, but only at a release point. Nonetheless, regarding the progressively lowered gas boundary, Green et al. ‘724 teaches providing “a smooth laminar flow” of reduction gas into a reactor chamber in order to not disrupt the reduction of a particle curtain of reduced metal [0051]. Though the reduced metal in Green et al. ‘724 is in the form of particulate streams referred to as particle curtains, one of ordinary skill in the art at the time of filing the invention would have been motivated by a desire to maintain controlled reduction of metal to flow reducing gas into the chamber of Murray ‘642 laminarly, based on the teachings of Green et al. ‘724.
It would have been obvious to one having ordinary skill in the art at the time of filing the invention to provide reducing gas in a flow that to at least dominant part is a laminar flow in order to ensure the complete exposure of charged metal within the furnace to reducing gas as well as reduce turbulence based on the teachings of Green et al. ‘724 at [0051], meeting the limitations of the instant Claims.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
CN 112410493 A teaches reducing metal powder with a mixture of hydrogen and nitrogen gas.
US 4089681 A teaches reducing metal bars under neutral gas with a mixture of hydrogen and nitrogen gas.
US 5885325 A teaches maintaining a laminar flow of gas in a second stage reactor for the manufacture of steel.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/M.S.S./Examiner, Art Unit 1733