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Claims 1 and 3, and 15-19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected Groups I and III respectively, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on 09/16/2025.
Applicant's election with traverse of Group II in the reply filed on 09/16/2025 is acknowledged. The traversal is on the grounds that the subject matter of claims 1-19 is interrelated to the extent that a search and examination of the subject matter of those claims in the same application would not be overburdensome (see pg. 6 of remarks), Lindstrom allegedly does not disclose a process in a fluidized bed operating as a “single stage” fluidized bed as claimed (see pg. 7-8 of remarks) and allegedly does not inject gaseous oxygen (see pg. 7-8 of remarks). This is not found persuasive because there is no requirement to establish a serious search or examination burden in order to make a restriction under unity of invention practice as in the in instant application, only that the claimed inventions lack unity of invention, and that the lack of unity of invention is not raised based on a narrow, literal, or academic approach (see MPEP 1850 (II)); the instant application defines a “single stage” to mean “that gas and solids are brought into contact with one another in the fluidized bed in such a way that they are mixed together in and reside at (or close to) a single, common operating temperature” (instant specification: pg. 5 lines 20-22) however Lindstrom teaches that gas 3 and solids 6 are mixed together and reside in the fluidized bed reactor (Fig. 4, Col. 5 lines 34-52), and while the reactor operates at different temperatures at different stages (Fig. 1, claim 1), the steps may all occur in a single reactor, where the entire reactor is at the same temperature during each stage (Claims 1, 15, 7-8, Col. 6 lines 47-51), Lindstrom teaching a single stage fluidized bed as claimed; and Lindstrom discloses the injection of gaseous oxygen in a stream with hot steam to the fluidized bed (Col. 5 lines 50-51).
The requirement is still deemed proper and is therefore made FINAL.
Response to Amendment
The amendment filed 09/16/2025 has been entered. Claims 1-19 are pending in this application, of which claims 1 and 4-14 are examined herein. Claims 1, 3 and 15-19 are withdrawn. Claims 1-2, and 15 are amended.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 05/10/2024 is in compliance with the provisions of 37 CFR 1.97 and is being considered by the examiner, with the exception of the following. MPEP 609.04(a)(II) states, in part, that “In addition to the list of information, each information disclosure statement must also include a legible copy of: … (B) Each publication or that portion which caused it to be listed , other than U.S. patents and U.S. patent application publications unless required by the Office”. In the instant case, no copy RU 2630136 C2 has been supplied with the IDS. While the IDS is being considered at this time, subsequent IDS documents are expected to conform to the aforementioned standards.
Claim Objections
Claims 6-9, and 11-14 are objected to because of the following informalities:
Claim 6: “includes” in line 1 should read “, further including”
Claim 7: “includes” in line 1 should read “, further including”
Claim 8: “includes” in line 1 should read “, further including”
Claim 9: “includes” in line 1 should read “, further including”
Claim 11: “includes” in line 1 should read “, further including”
Claim 11: “pressure drop of least” in lines 2-3 should read “pressure drop of at least”
Claim 12: “includes” in line 1 should read “, further including”
Claim 13: “includes” in line 1 should read “, further including”
Claim 14: “further includes” in line 1 should read “, further including”
Appropriate correction is required.
Claim Interpretation
Regarding claim 1, the phrase “single stage” is herein interpreted as “that gas and solids are brought into contact with one another in the fluidized bed in such a way that they are mixed together in and reside at (or close to) a single, common operating temperature” as defined at (instant specification: pg. 5 lines 20-22) 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 2 and 4-14 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.
The term “relatively lean” in claim 2 is a relative term which renders the claim indefinite. The term “relatively lean” 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 the pneumatic injection is performed.
Claim 8 recites the limitation "as measured by injection lance pressure drop" in line 3. The limitation is indefinite as it is unclear whether the mean time-average flow rate is actually measured by injection lance pressure drop in the method, or if instantaneous deviations in mass flow would be merely within the claimed ranges if measured using such. The limitation is further indefinite as neither the instant claims or instant specification disclose how a flow rate is determined by measuring pressure drop in the injection lance. Correction is required.
Claim 8 recites the limitation "the mean time-average flow rate” in line 3. There is insufficient antecedent basis for this limitation in the claim.
The term “smooth pneumatic injection” in claim 8 is a relative term which renders the claim indefinite. The term “smooth pneumatic injection” 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 the pneumatic injection is performed.
Claim 11 recites the limitation "the calculated bottom” in line 3. There is insufficient antecedent basis for this limitation in the claim.
Claim 11 recites the limitation "the cyclone inlet" in lines 3-4. There is insufficient antecedent basis for this limitation in the claim.
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.
Claims 2, 4-6, 9, and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Lindstrom (US 4360378 A, cited in IDS filed 11/21/2022) in view of Orth et al. (US 20080196549 A1, cited in IDS filed 11/21/2022).
Regarding claim 2, Lindstrom teaches a process for producing direct reduced iron (“DRI”) from iron-containing material and biofuel in a fluidized bed (Abstract, Col. 2 lines 31-42), wherein the iron-containing material may be iron ore concentrate (e.g., Col. 5 lines 3-7) and wherein the biofuel may comprise fuel wood or peat (i.e., biomass) (Col. 3 line 67-Col. 4 line 11). Lindstrom teaches the fluidized bed reactor comprising a single fluidized bed (Col. 2 lines 40-42, Col. 5 lines 34-52, Fig. 4). The instant application defines a “single stage” to mean “that gas and solids are brought into contact with one another in the fluidized bed in such a way that they are mixed together in and reside at (or close to) a single, common operating temperature” (instant specification: pg. 5 lines 20-22) however Lindstrom teaches that gas 3 and solids 6 are mixed together and reside in the fluidized bed reactor (Fig. 4, Col. 5 lines 34-52), and while the reactor operates at different temperatures at different stages (Fig. 1, claim 1), the steps may all occur in a single reactor, where the entire reactor is at the same temperature during each stage (Claims 1, 15, 7-8, Col. 6 lines 47-51), Lindstrom teaching a single stage fluidized bed as claimed.
Lindstrom teaches feeding iron ore into the fluidized bed (Fig. 1). Lindstrom teaches where the fluidized bed operates at temperatures such as 800 °C (Col. 2 line 66), which is within the claimed 750-850 °C range. Lindstrom teaches the biomass is a solid reductant consisting of dried biomass (Abstract, Col. 4 lines 11-22, Claims 4-5) and reducing iron ore and forming DRI in the fluidized bed (Abstract, Col. 2 lines 64-68), and discharging iron product (i.e., DRI) from the fluidized bed (Fig. 1).
Lindstrom does not teach the fluidized bed having a lower region, an intermediate region, or an upper region, pneumatically injecting solid reductant into the lower region of the bed, or injecting oxygen via one or more downward-facing nozzles.
Orth teaches a direct reduction process for a metalliferous material includes supplying the metalliferous material such as ore (Abstract, [0001]), a solid carbonaceous material, an oxygen-containing gas, and a fluidizing gas into a fluidized bed in a vessel (Abstract), therefore Orth and Lindstrom are analogous to the instant application as both are directed to direct reduction of iron ore to direct reduced iron. Orth teaches the fluidized bed having a metal-rich zone (i.e., a lower region) which has a higher volumetric concentration of DRI relative to the rest of the bed (Fig. 1, [0006]), an intermediate region which has a lower concentration of DRI and a higher concentration of char relative to the lower region (Fig. 1, [0007, 0038]). Orth teaches an upper region [0077], where as the upper region is neither metal or carbon rich [0006-0007], the upper region is relatively lean in both DRI and char. Orth teaches the solid feed materials (i.e., including solid reactant) are injected by a solids injection lance (i.e., pneumatically injecting solid reductant) [0063], where at least some solids from the solid reductant reach the lower region of the bed [0072]. Orth teaches injecting oxygen via a downward-facing nozzle 5 extending into the fluidized bed above the DRI-rich region 19 (Fig. 1, [0024-0025, 0064]). Orth teaches the fluidized bed can accept metalliferous feed material with a particle size of less than 100 microns without this material exiting the process entrained in off-gas due to an agglomeration mechanism operating within the fluidized bed that promotes a desirable level of agglomeration between particles of feed materials [0037].
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 a fluidized bed as taught by Orth as the fluidized bed of Lindstrom as doing so would allow use of metalliferous feed material with a particle size of less than 100 microns without negative effects as taught by Orth.
Regarding claim 4, Lindstrom teaches wherein the fluidized bed is a circulating fluidized bed (Col. 4 lines 56-57, Col. 6 line 68 - Col. 7 line 2).
Regarding claim 5, Lindstrom teaches feeding iron ore in the form of fines into the fluidized bed (Col. 2 lines 13-15).
Regarding claim 6, Lindstrom teaches pre-heating iron ore before feeding iron ore into the fluidized bed (Col. 3 lines 1-6).
Regarding claim 9, Lindstrom teaches injecting the reductant in the form of a free-flowing powder (Col. 4 lines 57-65), where as the powder is added to a gas fluidized bed (Col. 6 lines 28-29), the powder is amenable to smooth pneumatic injection as best can be understood in view of the rejection of claim 9 under 35 USC 112(b) above.
Regarding claim 14, Lindstrom teaches further melting DRI in an electric furnace (Col. 3 lines 28-34).
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Lindstrom in view of Orth as applied to claim 2 above, and further in view of Berg (US 20090000144 A1).
Regarding claim 7, Lindstrom teaches water content of the biomass should be reduced as much as possible by drying prior to injecting biomass into the fluidized bed (Col. 4 lines 11-20) wherein the biomass may be straw, bark, wood, or peat (Col. 3 lines 42-55, Col. 4 lines 1-10) and drying uses excess heat from the process (Col. 4 lines 18-22), however Lindstrom does not teach drying at a solids temperature below 250 °C prior to injecting biomass into the fluidized bed.
Berg teaches a method of drying solid materials and mixtures of solid materials (Title), wherein the materials dried may be biomass such as bark or wood chips [0037], thus Berg and Lindstrom are analogous to the instant application as both are directed to processes for drying biomass such as bark or wood. Berg teaches drying at gas temperatures of <200° C [0035], where as the gas used to dry the solids is at a temperature below 200 °C, the solids temperature also does not exceed 200 °C, thus Berg teaches drying at a solids temperature below 250 °C. Berg teaches advantageously it is possible to utilize low temperature waste heat available in the industry for drying, such as low temperature flue gases, hot air, hot water or steam; the required equipment require less space when the drying takes place in adjacent narrow passages; and the apparatus may be adjusted according to different process conditions, for example, flow character, humidity, temperature or amount of the material to be dried [0038-0041].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have dried the biomass of Lindstrom using the method of Berg the as Lindstrom teaches using excess heat from the process to perform drying, and Berg teaches a method of using excess heat to perform drying. Doing so would have been further obvious as Berg teaches the required equipment uses less space and may be adjusted according to different process conditions.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Lindstrom in view of Orth as applied to claim 2 above, and further in view of Maki et al. (US 4758117 A).
Regarding claim 8, Lindstrom teaches adding biomass as a particulate material (Col. 4 lines 61-65), but does not teach includes controlling injection of the reductant such that instantaneous deviations in mass flow are less than 15% of the mean time-average flow rate as measured by injection lance pressure drop.
Maki teaches a method for the transportation of a particulate material at controlled rate (Title), where particulate material is pneumatically transported with high accuracy and with rapid response to external disturbances by feedback control of a flow of booster gas (Abstract), thus Maki and Lindstrom are both analogous to the instant application as directed to systems handling particulate materials. Maki teaches when an external disturbance is added to the transportation system, the external disturbance is rap idly absorbed to maintain the acting capacity of the transportation system at a preset level (Col. 1 lines 11-14) and that in the instant case, the actual flow rate is maintained despite disturbances (Col. 4 line 67-Col. 5 line 10).
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 the method of Maki to feed the biomass in a particulate form of Lindstrom, as doing so would add the biomass with a high degree of accuracy as taught by Maki.
Maki, discussed above, is silent to controlling injection of the reductant such that instantaneous deviations in mass flow are less than 15% of the mean time-average flow rate as measured by injection lance pressure drop in the process described therein. However, it has long been held that where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation. See MPEP 2144.05 (II) A-B. In the instant case, one of ordinary skill would be motivated to minimize deviations in the flowrate of reductant.
Further, the mere recitation of a numerical parameter in an otherwise known process will not generally result in patentability of a claim directed to that process, absent evidence of criticality of the numerical parameter. In the instant case the numerical parameter (less than 15% of the mean time-average flow rate as measured by injection lance pressure drop) does not appear to be critical to the invention, at least for the reason it is recited solely in a dependent claim.
Thus, the disclosure of Lindstrom in view of Maki is held to establish a prima facie case of obviousness of a method as presently claimed.
Claims 10-11 are rejected under 35 U.S.C. 103 as being unpatentable over Lindstrom in view of Orth as applied to claim 2 above, and further in view of Lee et al. (US 5762681 A).
Regarding claim 10, Lindstrom does not teach wherein a fluidized bed pressure drop from an upper face of a gas distributor of the fluidized bed to a cyclone inlet of the fluidized bed (excluding gas distributor pressure drop) is at least 220 mbar.
Lee teaches a fluidized bed type reduction apparatus for iron ores and method for reducing iron ores using the apparatus (Title), where iron ore is reduced to reduced iron (abstract), thus Lee and Lindstrom are analogous to the instant application as both are directed to methods of producing reduced iron from ore in a fluidized bed. Lee teaches the pressure drop in fluidized beds for reducing iron should be 0.3-0.6 atm (304-608 mbar) (Col. 15 lines 38-42), and the reduction fluidized beds 20/20A are connected to a cyclone 60 at the outlet (Fig. 2 and 3, Col. 3 lines 11-13). As a gas distributor and cyclone inlet respectively precede and follow the fluidized bed of the fluidized bed reactor, the pressure drop between the gas distributor and cyclone inlet must be at least 304-608 mbar as a pressure drop of 304-608 mbar occurs between the two points (i.e., wherein a fluidized bed pressure drop from an upper face of a gas distributor of the fluidized bed to a cyclone inlet of the fluidized bed (excluding gas distributor pressure drop) is at least 220 mbar). Lee teaches the cyclone captures dusty iron ores contained in exhaust gas from the reduction furnace (Col. 3 lines 12-13), where the bottom portion of the cyclone is connected to an ore discharge line which feeds into a duct line to recycle the collected ore (Col. 6 lines 12-19, Fig. 2 and 3, Col. 24 lines 23-35).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added a cyclone at the fluidized bed outlet as taught by Lee to the fluidized bed of Lindstrom, as doing so would collect and recycle any fine iron ore in the off gas stream from the reactor.
Further, because Lindstrom is silent with respect to a suitable pressure drop in the fluidized bed, in order to carry out the invention of Lindstrom one of ordinary skill in the art would necessarily look to the art for a reference teaching a fluidized bed pressure drop suitable for use within the process of Lindstrom, such as a pressure drop of 304-608 mbar as taught by Lee. As Lindstrom and Lee both relate to fluidized beds for reducing iron ore to reduced iron, one of ordinary skill would be motivated to use the pressure drop of the fluidized beds of Lee.
Regarding claim 11, Lindstrom teaches adding biomass 5 below the gas distributing plate 2 (Lindstrom: Fig. 4, Col. 5 lines 34-41), wherein as the biomass is incorporated into the fluidized bed (e.g., Lindstrom: Col. 4 lines 57-67, Col. 6 lines 28-30), any resulting plume of biomass passes through the fluidized bed. Lee teaches a pressure drop in the fluidized bed of 0.3-0.6 atm (304-608 mbar) (Lee: Col. 15 lines 38-42), where as the cyclone and where the biomass is added (i.e., a bottom of the biomass injection plume) respectively precede and follow the fluidized bed of the fluidized bed reactor, the pressure drop between the gas distributor and cyclone inlet must be at least 304-608 mbar as a pressure drop of 304-608 mbar occurs between the two points (i.e., a resulting plume passes through the fluidized bed with a pressure drop of least 200 mbar from the calculated bottom of the biomass injection plume to the cyclone inlet).
Claim 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Lindstrom in view of Orth as applied to claim 2 above, and further in view of Marsh et al. (US 20090324440 A1, cited in IDS filed 11/21/2022).
Regarding claim 12, Lindstrom teaches attaining a 90-95% degree of reduction (i.e., 5-10% of the iron ore remains in an unreduced oxide form after reduction) (Col. 1 lines 35-36), however Lindstrom does not teach further reducing DRI from the fluidized bed in a microwave furnace having a non-oxidizing atmosphere.
Marsh teaches reduction processing of metal-containing ores in the presence of microwave energy (Title), wherein the metal-containing material has metal in a positive oxidation state [0044] and the metal is preferably a transition metal such as iron [0045], thus Lindstrom and Marsh are analogous to the instant application as both are directed to methods of reducing iron ores. Marsh teaches reducing under a reducing gas (i.e., non-oxidizing) atmosphere [0094]. Marsh teaches the method has improved reduction kinetics and in turn significant energy savings [0139], and a greater degree of metallization [0139]. Marsh teaches iron is further metallized by treatment with microwaves over conventional treatment such as in a fluidized bed alone, which exceeds 95% (Example 5, Fig. 20), (i.e., further reducing DRI from the fluidized bed in a microwave furnace having a non-oxidizing atmosphere).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have further reduced the DRI of Lindstrom in a microwave furnace as taught by Marsh as doing so would further reduce the iron and achieve a greater level of metallization with reduced energy usage as taught by Marsh.
Regarding claim 13, Marsh teaches a solid containing fixed carbon material [0057, 0088-0089], wherein the solid containing fixed carbon material may be part of the metal-containing feed (i.e., forming a blend of solid containing fixed carbon and DRI from the fluidized bed) [0091]. Marsh teaches feeding the blend into the microwave furnace to facilitate further reduction of the DRI (e.g., [0132]).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Nikolas T Pullen whose telephone number is (571)272-1995. The examiner can normally be reached Monday - Thursday: 10:00 AM - 6:00 PM EST.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733