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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 03/06/2026 is being considered by the examiner.
Response to Amendments / Status of Claims
An amendment, filed 04/09/2026, is acknowledged.
Claims 1-10 and 12-14 are currently pending.
Claims 1, 4, 7, 10, 12, and 13 have been amended.
Claim 11 is cancelled.
Therefore, claims 1-10 and 12-14 are currently under consideration for this office action.
Status of Previous Rejections
The previous specification objection due to abstract has been withdrawn, due to amendments.
The previous 35 USC § 112 (b) rejections of the claims have been withdrawn, due to amendments.
The previous 35 USC § 102(a)(1) and 35 USC § 103 rejections of the claims have been maintained but rewritten wherever applicable due to the amendments.
Claim Rejections - 35 USC § 102(a)(1)
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claim 1, and 3-6 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Kenji Nakase et al. [US9957581B2] (hereinafter “Nakase”).
Regarding claim 1, Nakase discloses a molten iron refining method in which an auxiliary material is added, and an oxidizing gas is supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained or fed in a converter vessel, and molten iron is subjected to a refining process (method for refining hot metal (also called molten iron) in a converter by blowing an oxidizing gas from a top-blowing lance onto the hot metal to dephosphorize or decarburize the hot metal, while forming a flame at the leading end of a top-blowing lance to increase the temperature of the hot metal with the sensible heat of a powder heated by the flame or with the heat of combustion of a combustible material combusted by the flame so that the content of a cold iron source such as iron and steel scrap can be increased) [Abstract, Col.1, line 6-15].
Nakase discloses prior to the refining process, a pre-charged cold iron source that is part of the cold iron source and charged all at once into the converter vessel before the molten pig iron is charged into the converter vessel (converter equipment 1 is used to perform the dephosphorization of the hot metal 26, a cold iron source is first charged into the converter. cold iron sources include iron and steel scrap such as cropping scrap from slabs and steel sheets produced in steel mills and commercial scrap, metal recovered from slag by magnetic separation, cold pig iron, and direct- reduced iron) [Col.7, line 46-54]. Nakase also discloses, the pre-charged cold iron source content is 5% by mass or more of all iron sources charged. The cold iron source content is defined by equation (1 ):
cold iron source content (% by mass) = (amount of cold iron source) x 100/(amount of hot metal+ amount of cold iron source)
Nakase discloses a cold iron source content of 5% by mass or more, which is 0.05 times of a sum of an amount of the pre-charged cold iron source and a charge amount of the molten pig iron (amount of hot metal+ amount of cold iron source) [Col.7, line 55-61, equation (1)].
Therefore, Nakase’s cold iron source is charged in an amount which is within the range as recited in the instant claim.
Therefore, it is anticipatory when the prior art is within a claimed range. [See MPEP § 2131.03].
Nakase discloses a furnace-top-added cold iron source that is part or all of the cold iron source and added from a furnace top of the converter vessel is fed into the converter vessel during the refining process (after the cold iron source is charged (pre-charged cold iron) into the converter, the hot metal 26 is charged into the converter [Col. 8 line 4-8], the carrier gas to blow the refining powder 29, from the central hole 16 of the top-blowing lance 3 onto the surface of the hot metal 26) [Col. 8 line 21-26] and the refining powder 29 contains an iron oxide such as iron ore, sintered iron ore powder, mill scale, or steel mill dust is used as, the iron oxide functions as an oxygen source) [Col.9 line 30-38]. According to these teachings of Nakase and as shown in Nakase’s FIG. 1 and 2, the refining powder 29 containing iron oxide is blown from a top-blowing lance into the converter (a furnace-top-added cold iron source) [FIG. 1 and 2].
Nakase discloses a burner is further used that is provided at a leading end of the top-blowing lance or at a leading end of a second lance installed separately from the top-blowing lance, and that has spray holes through which a fuel and a combustion-supporting gas are ejected (a burner flame at the leading end of the top-blowing lance to transfer the heat of the flame to the hot metal in the converter, [Col.3, line 29-37] and before, during, or after the blowing of the refining powder 29, a flame is formed below the top-blowing lance 3 by ejecting the fuel gas from the fuel gas ejection hole 17 and ejecting the combustion oxidizing gas from the combustion oxidizing gas ejection hole 18 [Col.8, line 21-35]).
Nakase discloses during at least part of a period of the refining process, a powdery auxiliary material or an auxiliary material processed into powder that is at least part of the auxiliary material is blown in so as to pass through a flame formed by the burner (the refining powder 29 passes through a flame formed below the leading end of the top-blowing lance 3 by the fuel gas, and the heat of the flame is efficiently transferred to the refining powder 29, and the refining powders 29, a lime-based flux and iron oxide, are noncombustible, are heated to high temperature and transfer the heat of the flame to the hot metal 26) [Col. 10, line 18-25].
Regarding Claim 3, all the above discussions regarding claim 1 are applicable here, in addition, Nakase discloses the refining process is a decarburization process of molten iron (the oxidation refining processes in which a refining oxidizing gas is supplied from a top-blowing lance to hot metal in a converter and is applied to hot-metal decarburization) [Col. 4, line 46-50].
Regarding Claim 4, all the above discussions regarding claim 1 and 3 are applicable here, in addition, Nakase discloses the refining process is a decarburization process that is performed with a converter vessel in which molten pig iron dephosphorized beforehand is charged (hot-metal decarburization is performed using hot metal dephosphorized as a pretreatment in advance and is applied to the dephosphorization of hot metal and then to the decarburization of the dephosphorized hot metal in a converter) [Col. 4, line 53-58].
Regarding Claim 5, all the above discussions regarding claim 1 are applicable here, wherein Nakase already discloses the refining process is a dephosphorization process of molten iron (converter equipment 1 is used to perform the dephosphorization of the hot metal 26, wherein a cold iron source is first charged into the converter body 2) [Col.7, line 46-54]. Nakase discloses Examples 1 to 6, iron and steel scrap was charged into the converter, and hot metal at 1350°C is then charged into the converter. The hot metal is then dephosphorized by blowing quicklime (refining powder), a fuel gas (propane gas), combustion oxygen gas, and refining oxygen gas from the top-blowing lance onto the hot metal [Col. 12, line 6-13].
Regarding Claim 6, all the above discussions regarding claim 1 and 5 are applicable here, it is to be noted, claim recites “or” in between two condition, therefore, prior art teaches either of the condition or both meet the limitation. Nakase discloses one or both of the following conditions are met: that the concentration of carbon contained in the furnace-top-added cold iron source is not lower than 0.3 mass%, and that the temperature of the molten iron upon completion of the dephosphorization process is higher than a temperature (The amount of iron and steel scrap charged is adjusted such that the temperature of the hot metal after dephosphorization is 1400° C) [Col. 12, line 24-27].
Nakase’s temperature of the molten iron upon completion of the dephosphorization process is within the range as recited in the instant claim.
Therefore, it is anticipatory when the prior art is within a claimed range. [See MPEP § 2131.03].
Claim 1 and 3-6 are alternatively rejected under 35 U.S.C. 102(a)(1) as being anticipated by Takahashi et al. [JP2013209738A, (Machine translation hereinafter “Takahashi”).
Regarding claim 1, Takahashi teaches a molten iron refining method in which an auxiliary material is added, and an oxidizing gas is supplied through a top-blowing lance, to a cold iron source and molten pig iron that are contained or fed in a converter vessel, and molten iron is subjected to a refining process, wherein prior to the refining process, a pre-charged cold iron source that is part of the cold iron source and charged all at once into the converter vessel before the molten pig iron is charged into the converter vessel (a method for producing molten steel from molten pig iron by charging the molten pig iron tapped from a blast furnace into a converter and subjected the molten pig iron to preliminary dephosphorization and then the molten pig iron is subjected to decarburization refining) [Section 0001] and (when pre-dephosphorizing molten iron using this top-blowing lance 1, first, a cold iron source is charged into the converter [Section 0022], then molten pig iron is charged into the converter, [Section 0023], after the molten iron is charged, a top-blowing lance is inserted into the converter to inject a gas fuel, a combustion oxidizing gas, and a combustible substance, including iron ore powder, mill scale, powdered lime-based flux, coke powder, or waste plastic molding powder) [Section 0024].
Takahashi teaches the cold iron source has a blending ratio of 5 mass% or more relative to the total iron sources to be charged, i.e., blending ratio of cold iron (mass%) = blending amount of cold iron/ (blending amount of molten iron + blending amount of cold iron) * 100 [Section 0022-0023].
Therefore, Takahashi’s cold iron source is charged in an amount which is within the range as recited in the instant claim.
Therefore, it is anticipatory when the prior art is within a claimed range. [See MPEP § 2131.03].
Takahashi teaches a furnace-top-added cold iron source that is part or all of the cold iron source and added from a furnace top of the converter vessel is fed into the converter vessel during the refining process (after the molten iron is charged, a top-blowing lance is inserted into the converter to inject a gas fuel, a combustion oxidizing gas, and a combustible substance, including iron ore powder, mill scale, powdered lime-based flux, coke powder, or waste plastic molding powder are sprayed onto the molten iron bath surface from the powdered refining agent injection holes of the top-blowing lance 1) [Section 0024] and preliminary dephosphorization of the molten pig iron is carried out by supplying an oxygen source, such as oxygen gas, iron oxide to the molten pig iron and oxidizing the phosphorus in the molten pig iron to form phosphorus oxides. When iron oxide powder is not supplied from the powdered refining agent injection holes 4, iron oxide is added from the converter furnace upper hopper to the converter) [Section 0026-0027]. According to above Takahashi’s teachings and as shown in Takahashi’s Fig. 1, iron ore powder, mill scale, iron oxide powder are injected either from a top-blowing lance is inserted into the converter, or from the upper hopper of the converter i.e. Takahashi’s iron source is a furnace-top-added cold iron source.
Takahashi teaches a burner is further used that is provided at a leading end of the top-blowing lance or at a leading end of a second lance installed separately from the top-blowing lance, and that has spray holes through which a fuel and a combustion-supporting gas are ejected (a gas fuel such as propane gas, natural gas, or coke oven gas, or a hydrocarbon liquid fuel such as heavy oil or kerosene, is supplied from the fuel injection holes 5 of the top-blowing lance 1, and a combustion oxidizing gas such as oxygen gas or air is supplied from the combustion oxidizing gas injection holes 6, and they combust when the fuel concentration reaches the combustion limit range and a flame is formed below the top-blowing lance 1) [Section 0024-0025].
PNG
media_image1.png
200
400
media_image1.png
Greyscale
Takahashi teaches during at least part of a period of the refining process, a powdery auxiliary material or an auxiliary material processed into powder that is at least part of the auxiliary material is blown in so as to pass through a flame formed by the burner (The powdered refining agent supplied from the powdered refining agent injection holes 4 is heated or heated and melted by the heat of the flame that is formed, and is sprayed onto the bath surface of the molten pig iron in the heated or melted state) [Section 0025, Fig.1], (in the preliminary dephosphorization treatment and converter decarburization refining, the powdered refining agent or powdered flux is being heated by a flame formed below the tip of the top lance, so that the heat of the flame is transferred to the molten pig iron through the powdered refining agent or powdered flux [Section 0049].
The paragraph [0025] of the instant specification describes that a powdery auxiliary raw material is heated in a burner flame by using a lance in which a powder supply pipe is arranged at the center and a fuel supply pipe having an injection hole and a combustible gas supply pipe are arranged in order around the powder supply pipe, and the powdery auxiliary material supplied through the powder supply pipe is blown in so as to pass through a flame formed by this burner. According to this paragraph, and the above Takahashi’s teachings and as well as shown in Takahashi’s Fig.1, the powdered refining agent injection holes 4, is being heated by a flame formed below the tip of the top lance, and is sprayed onto the bath surface of the molten pig iron, Takahashi’s powdered refining agent (auxiliary material) would pass through a flame formed below the lower end.
Regarding Claim 3-5, all the above discussions regarding claim 1 are applicable here, in addition, Takahashi teaches after the preliminary dephosphorization treatment, the converter is tilted and the pre-dephosphorized molten iron is tapped into a molten iron holding vessel such as a ladle or a converter charging ladle [Section 0035]. Takahashi teaches during the decarburization step, a cold iron source is charged into a converter before charging the molten iron from the ladle into the converter [Section 0041]. Once the molten pig iron has been charged into the converter, a top-blowing lance is inserted into the converter and oxygen gas is sprayed onto the surface of the molten pig iron bath in order to decarburize and refine the molten iron [Section 0042].
With respect to claim 6, Takahashi teaches the molten iron temperature would be 1400°C at the end of the preliminary dephosphorization treatment [Section 0054], which is within the as recites in the instant claim.
Therefore, it is anticipatory when the prior art is within a claimed range. [See MPEP § 2131.03].
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim 2, 9-12 are rejected under 35 U.S.C. 103 as being unpatentable over Kenji Nakase et al. [US9957581B2] (hereinafter “Nakase”) as applied to claim 1.
Regarding Claim 2, all the above discussions regarding claim 1 are applicable here, although Nakase longest dimension of the furnace-top-added cold iron source to be 100 mm, it would have been obvious to one of ordinary skill in the art to change the dimension, i.e., longest dimension of the furnace-top-added cold iron source to be 100 mm from Nakase’s teaching, since such a modification would have involved a mere change in the dimension of a component. A change in dimension is generally recognized as being within the level of ordinary skill in the art. In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955). Change in size and shape is not patently distinct over the prior art absent persuasive evidence that the particular configuration of the claimed invention is significant. See In re Rose, 220 F.2d 459, 105 USPQ 237 (CCPA 1955); In re Rinehart, 531 F.2d 1048, 189 USPQ 143 (CCPA 1976); In re Dailey, 357 F.2d 669, 149 USPQ 47 (CCPA 1966). MPEP 2144.04 IV(A). In addition, the instant specification is silent to unexpected results.
In this case, Nakase discloses in FIG. 2, the central hole 16 [Col. 7, line 34 and FIG.2], and the refining powder 29, which is at least one of a lime-based flux, iron oxide, and a combustible material, is charged from the central hole 16 of the top-blowing lance 3 onto the surface of the hot metal 26 [Col. 8, line 23-26]. Nakase also discloses the refining powder 29 contains an iron oxide such as iron ore, sintered iron ore powder, mill scale, or steel mill dust is used as, the iron oxide functions as an oxygen source during dephosphorization [Col.9 line 30-38]. According to these teachings of Nakase and Nakase’s FIG. 1 and 2, the refining powder 29 containing an iron oxide is blown from a top-blowing lance through the central hole 16 into the converter is a furnace-top-added cold iron source [FIG. 1 and 2] and Nakase further teaches the central hole had an inner diameter of 11.5 mm [Col. 11, line 5-6]. Therefore, it would have been obvious to one of ordinary skill in the art to change the dimension of the product to be charged, i.e., longest dimension of Nakase cold iron source to be less than 11.5 mm so as to be charged through the central hole of the Nakase, which is within the as recited longest dimension of the furnace-top-added cold iron source of claim 2.
Regarding Claim 9 , all the above discussions regarding claim 1-2 are applicable here, wherein Nakase already discloses the refining process is a dephosphorization process of molten iron (converter equipment 1 is used to perform the dephosphorization of the hot metal 26, wherein a cold iron source is first charged into the converter body 2) [Col.7, line 46-54]. Nakase discloses Examples 1 to 6, iron and steel scrap was charged into the converter, and hot metal at 1350°C is then charged into the converter. The hot metal is then dephosphorized by blowing quicklime (refining powder), a fuel gas (propane gas), combustion oxygen gas, and refining oxygen gas from the top-blowing lance onto the hot metal [Col. 12, line 6-13].
Regarding Claim 10, all the above discussions regarding claim 1-2 and 9 are applicable here, in addition, Nakase discloses the refining process is a decarburization process that is performed with a converter vessel in which molten pig iron dephosphorized beforehand is charged (hot-metal decarburization is performed using hot metal dephosphorized as a pretreatment in advance and is applied to the dephosphorization of hot metal and then to the decarburization of the dephosphorized hot metal in a converter) [Col. 4, line 53-58].
Regarding Claim 12, all the above discussions regarding claim 1-2 and 11 are applicable here, it is to be noted, claim recites “or” in between two condition, therefore, prior art teaches either of the condition or both meet the limitation. Nakase discloses one or both of the following conditions are met: that the concentration of carbon contained in the furnace-top-added cold iron source is not lower than 0.3 mass%, and that the temperature of the molten iron upon completion of the dephosphorization process is higher than a temperature (The amount of iron and steel scrap charged is adjusted such that the temperature of the hot metal after dephosphorization is 1400° C) [Col. 12, line 24-27].
Claims 7-8, and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Kenji Nakase et. al. [US9957581B2] (hereinafter “Nakase”) as applied to claim 1, and further in view of Matsuzawa Akihiro et. al. [WO2019039326A1] (Machine translation, hereinafter “Akihiro”).
Regarding Claim 7 and 13, all the above discussions regarding claim 1 are applicable here, in addition, Nakase discloses the refining process is a dephosphorization-decarburization process in which a molten iron dephosphorization step, and a molten iron decarburization step are performed as a series of processes in the same converter vessel (hot-metal decarburization is performed using hot metal dephosphorized as a pretreatment in advance and the method of refining is applied to the dephosphorization of hot metal and then to the decarburization of the dephosphorized hot metal in a converter) [Col. 4, line 53-58].
Nakase discloses prior to the molten iron dephosphorization step, the pre-charged cold iron source is charged in an amount not larger than 0.15 times a sum of an amount of the pre-charged cold iron source and a charge amount of the molten iron, or is not charged (converter equipment 1 is used to perform the dephosphorization of the hot metal 26, wherein a cold iron source is first charged into the converter body 2. Examples of cold iron sources include iron and steel scrap such as cropping scrap from slabs and steel sheets produced in steel mills and commercial scrap, metal recovered from slag by magnetic separation, cold pig iron, and direct- reduced iron) [Col.7, line 46-54]. Nakase discloses, the cold iron source content is 5% by mass or more of all iron sources charged. The cold iron source content is defined by equation (1 ):
cold iron source content (% by mass) = (amount of cold iron source) x 100/(amount of hot metal+ amount of cold iron source)
Nakase discloses a cold iron source content of 5% by mass or more, which is 0.05 times of a sum of an amount of the pre-charged cold iron source and a charge amount of the molten pig iron (amount of hot metal+ amount of cold iron source) [Col.7, line 55-61, equation (1)].
Therefore, Nakase’s cold iron source is charged in an amount which is within the range as recited in the instant claim.
It is to be noted the claim recites “or” in between the molten iron dephosphorization step and the molten iron decarburization step, therefore, cold iron added either of these two step read on the claim, and Nakase discloses the furnace-top-added cold iron source is added to the molten iron during one or both of the molten iron dephosphorization step and the molten iron decarburization step (pre-charged cold iron) into the converter body 2, the hot metal 26 is charged into the converter body 2) [Col. 8 line 4-8]. (Then, the fuel gas alone or a mixture of the fuel gas and the inert gas is then supplied to the dispenser 13 as the carrier gas to blow the refining powder 29, from the central hole 16 of the top-blowing lance 3 onto the surface of the hot metal 26) [Col. 8 line 21-26]. (The dephosphorization reaction of the hot metal 26 proceeds such that the phosphorus in the hot metal 26 reacts with the oxidizing gas or iron oxide to form phosphorus oxide, and the phosphorus oxide is absorbed into the slag 27) [Col.9 line 4-8]. (The refining powder 29 contains an iron oxide such as iron ore, sintered iron ore powder, mill scale, or steel mill dust is used as, the iron oxide functions as an oxygen source. A dephosphorization reaction proceeds as the iron oxide reacts with the phosphorus in the hot metal. The iron oxide also reacts with the lime-based flux to form FeO-CaO on the surface of the lime-based flux. This promotes the formation of slag from the lime-based flux and thus promotes the dephosphorization reaction) [Col.9 line 30-38]. According to these teachings of Nakase and Nakase’s FIG. 1 and 2, the refining powder 29 containing an iron oxide is blown from a top-blowing lance into the converter (a furnace-top-added cold iron source) [FIG. 1 and 2]. Nakase further teaches the dephosphorization of hot metal in a converter has been described as an example, which is also be applied to the decarburization of hot metal in a converter using the oxidation refining process as described above [Col. 12, line 33-37].
Nakase discloses during further, during at least part of a period of one or both of the molten iron dephosphorization step and the molten iron decarburization step, the powdery auxiliary material or the auxiliary material processed into powder is blown in so as to pass through a flame formed by the burner (the refining powder 29 passes through a flame formed below the leading end of the top-blowing lance 3 by the fuel gas, and the heat of the flame is efficiently transferred to the refining powder 29. Among the refining powders 29, a lime-based flux and iron oxide, which are noncombustible, are heated to high temperature. These refining powders transfer the heat of the flame to the hot metal 26) [Col. 10, line 18-25].
But Nakase is silent about an intermediate slag-off step in between dephosphorization step and decarburization step are performed.
However, Akihiro teaches foaming of converter slag occurs when carbon in the molten iron reacts with oxygen gas or FeO in the slag during blowing, generating a large number of CO bubbles that remain in the slag, the foamed slag is then discharged from the furnace throat and collected in a slag pan installed below the convertor. The more slag discharged into the slag discharge ladle, the less SiO2 and P2O5 remain in the furnace, and the amount of refining materials such as quicklime used in the refining performed after intermediate slag discharge can be reduced [Section 0004]. Akihiro teaches a method for efficiently suppressing slag foaming wherein the process is used in a converter refining system in which dephosphorization blowing, intermediate slag removal, and decarburization blowing are successively performed in one converter [Section 0011] and the converter refining method in which molten pig iron is charged into one converter and subjected to desiliconization and dephosphorization blowing, the converter is tilted while the molten pig iron remains in the converter to discharge slag from the throat, and the converter is returned to a vertical position and subsequently subjected to decarburization blowing [Section 0015].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Akihiro’s teachings to modify Nakase for performing dephosphorization blowing, intermediate slag removal, and decarburization blowing are successively performed in one converter for efficient suppression of slag foaming and reduced amount of refining materials.
Regarding Claim 8 and 14, all the above discussions regarding claim 1 and 7 are applicable for claim 8 and all the above discussions regarding claim 1-2 and 13 applicable for claim 14, it is to be noted, claim recites “or” in between two condition, therefore, prior art teaches either of the condition or both meet the limitation. Nakase discloses one or both of the following conditions are met: that the concentration of carbon contained in the furnace-top-added cold iron source is not lower than 0.3 mass%, and that the temperature of the molten iron upon completion of the dephosphorization process is higher than a temperature (The amount of iron and steel scrap charged is adjusted such that the temperature of the hot metal after dephosphorization is 1400°C. That is, more iron and steel scrap is being charged when the hot metal had a larger thermal margin) [Col. 12, line 24-27].
Nakase’s temperature of the molten iron upon completion of the dephosphorization process is within the range as recited in the instant claim.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected the temperature of the molten iron upon completion of the dephosphorization process from the teachings of Nakase that falls within the instantly-claimed ranges, because “In the case where the 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)” [See MPEP § 2144.05.I].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have Akihiro’s temperature of the molten iron upon completion of the dephosphorization process for more iron and steel scrap is being charged when the hot metal had a larger thermal margin.
Claim 2, 9-10 and 12 are alternatively rejected under 35 U.S.C. 103 as being unpatentable over Kenji Nakase et al. [US9957581B2] (hereinafter “Nakase”) as applied to claim 1 and further in view of [JP6648542B2] ((Machine translation, hereinafter “JP’542B2”).
Regarding Claim 2, all the above discussions regarding claim 1 are applicable here, while Nakase is sufficient to meet this limitation that has already been shown above.
Alternatively, JP’542B2 teaches a method of molten hot metal comprises: a classification step of classifying the rough pig iron with a sieve machine to separate it into small diameter rough pig iron that can be charged from an upper hopper of a furnace and large diameter rough pig iron including rough pig iron with a diameter larger than the small diameter rough pig iron; and a dephosphorization step of dephosphorizing the molten pig iron that has been subjected to the desulfurization step in a dephosphorization furnace [Section 0023]. JP’542B2 in the dephosphorization and decarburization processes, rough pig iron is charged (injected) in an amount such that the [S] of the molten pig iron or molten steel that has undergone these processes does not exceed a predetermined control value. Therefore, the molten steel obtained through the decarburization process is likely to have sufficiently reduced P and S contents, and there is a high possibility that low-phosphorus, low-sulfur steel can be produced without desulfurization in the secondary refining process. Therefore, the risk of having to transfer steel types can be reduced [Section 0024]. JP’542B2 teaches while the scrap chute can charge raw materials with a maximum diameter of about 1000 mm, but the furnace hopper can only charge raw materials with a maximum diameter of about 50 to 100 mm. Therefore, the size of small-diameter rough pig iron is adjusted depending on the specifications of each facility such as the furnace hopper of the converter [Section 0031]. JP’542B2 then teaches during a refining process, flux is added to molten pig iron (low-phosphorus, low-sulfur molten pig iron) that has undergone a dephosphorization process in a decarburization furnace, followed by oxygen blowing to decarburize the molten pig iron, thereby obtaining low-phosphorus, low-sulfur molten steel with a reduced C content. The decarburization furnace shall be equipped with an upper hopper. The hopper above the furnace stores the small diameter rough iron obtained in the classification process [Section 0036]. Therefore, JP’542B2’s small diameter rough iron is a furnace-top-added cold iron, which have a maximum diameter that is within the as recited in the instant claim.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filling date of the present invention, to have selected a maximum diameter of a furnace-top-added cold iron from the teachings of JP’542B2 teaches that falls within the instantly-claimed ranges, because “In the case where the 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)” [See MPEP § 2144.05.I].
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filling date of the present invention, to have JP’542B2’s teachings to modify Nakase to adjust the dimension of the furnace top added cold iron source to the size of small-diameter depending on the specifications of each facility of the furnace top charging means of the converter.
Response to Arguments
Applicant's arguments filed on 04/09/2026 have been fully considered but they are not persuasive.
Applicant’s argument regarding the 102(a)(1) rejection of claim 1 as anticipated by the prior art is Kenji Nakase et al. [US9957581B2] (hereinafter “Nakase”), have been fully considered, but does not seem persuasive.
With respect to Applicant’s arguments “Nakase fails to disclose the limitation of claim 1, “a furnace-top-added cold iron source that is part of the cold iron source and added from a furnace top of the converter vessel is fed into the converter vessel during the refining process”, as Applicant does not agree that Nakase's refining powder 29 is a furnace-top-added cold iron source that is part of the cold iron source as recited in claim 1. Nakase's refining powder 29 cannot be both: 1) a furnace-top-added cold iron source that is part of the cold iron source and added from a furnace top of the converter vessel, and 2) a powdery auxiliary material that is blown in so as to pass through a flame formed by the burner that is provided at a leading end of a lance, as recited in claim 1. It is clear from Nakase' s Fig. 1 that the refining powder 29 passes from a bottom of the lance 3, and thus can reasonably correspond to only an auxiliary material that passes through a flame that is provided at a leading end of the lance 3. The refining powder 29 is not also a cold iron source that is added from a furnace top of the converter body 2.” does not seem persuasive, because,
PNG
media_image2.png
892
598
media_image2.png
Greyscale
[AltContent: textbox (US9957581B2)]Claim 1 does not define what is the cold iron source or any particular cold iron source. But according to the instant specification, the cold iron source is likely iron scrap, also claim 1 recites two cold iron source one is pre-charged cold iron before the charging the molten metal, and the other is top-added cold iron during refining step. Nakase also teaches two source of cold iron, pre-charged cold iron source (a cold iron source is first charged into the converter body 2, before charging the hot metal) and cold iron sources include iron and steel scrap such as cropping scrap from slabs and steel sheets produced in steel mills and commercial scrap, metal recovered from slag by magnetic separation, cold pig iron, and direct- reduced iron [Col.7, line 46-54], and a refining iron powder during the refining process. As shown, Nakase's refining powder 29 is added from the top of the convertor through the lance 3 (see Nakase’s FIG.1) not from the bottom of the convertor. Nakase teaches to increase the content of cold iron sources (iron sources at ordinary temperature) (Col. 1, line 22-24) and Nakase also teaches to increase the thermal margin of hot metal during the dephosphorization or decarburization of the hot metal so that the content of cold iron sources can be increased (Col. 1, line 52-55), one of the provided solution is a method in which a heat transfer medium such as cold iron (iron and steel scrap powder, ferroalloy powder) or slag/auxiliary material (quicklime powder) is supplied together with oxygen gas from a top-blowing lance to hot metal in a refining vessel (Col. 1, line 22-65). Nakase teaches if an iron oxide such as iron ore, sintered iron ore powder, mill scale, or steel mill dust is used as the refining powder 29, the iron oxide functions as an oxygen source (these all are the source of cold iron, see, Nakase’s Col.7, line 51-55). A dephosphorization reaction proceeds as the iron oxide reacts with the phosphorus (refining process)in the hot metal (Col. 9, line 30-33). Nakase further teaches if the refining powder 29 is a mixture of a lime-based flux, iron oxide, and a combustible material, their respective effects can be simultaneously achieved (Col. 9, line 57-59), i.e. Nakase’s refining powder 29 can be either cold iron source, or lime based flux or can be both.
Applicant’s argument regarding the 102(a)(1) rejection of claim 1 as anticipated by the prior art is Takahashi et al. [JP2013209738A, (Machine translation, hereinafter “Takahashi”), have been fully considered, but does not seem persuasive.
With respect to Applicant’s arguments, regarding Takahashi is, “Similar to Nakase, Takahashi fails to disclose using the furnace-top-added cold iron source that is part of the cold iron source as defined by claim 1. the use of an iron ore powder, which is not the same as the recited cold iron source. Takahashi's iron ore powder cannot be both: 1) a furnace-top-added cold iron source that is part of the cold iron source and added from a furnace top of the converter vessel, and 2) a powdery auxiliary material that is blown in so as to pass through a flame formed by the burner that is provided at a leading end of a lance, as recited in claim 1. In addition, Takahashi does not state that both features are used. Takahashi's paragraph [0027] states "in the case where the iron oxide powder is not supplied from the powdery refining agent injection holes 4, the iron oxide is charged from the upper hopper of the converter furnace" ( emphasis added). Takahashi thus discloses having the iron ore powder injected via the holes 4 or from the upper hopper, but not both.2.”, does not seem persuasive, because,
As shown above, claim does not specify what is cold iron and according to the instant specification, the cold iron source is likely iron scrap, Takahashi’s pre-charged cold iron before the charging the molten metal [0022] is different and Takahashi teaches another cold iron that is iron ore powder, mill scale etc. during the refining process, which reads on the cold iron source during the refining process. Takahashi teaches, at the same time, one or more of the following combustible substances, such as iron ore powder, mill scale (cold iron source), powdered lime-based flux, coke powder, or waste plastic molding powder (auxiliary material), are sprayed onto the molten iron bath surface from the powdered refining agent injection holes 4 of the top-blowing lance (Takahashi’s [0024]). Takahashi further teaches in the preliminary dephosphorization of molten pig iron, it is essential to supply an oxygen source such as oxygen gas or iron oxide and a lime-based flux (Takahashi’s [0026], and iron oxide powder serves as an oxygen source for forming phosphorus oxides. When iron oxide powder is not supplied from the powdered refining agent injection holes 4, iron oxide is added from the converter furnace upper hopper to the converter (Takahashi’s [0027]). Therefore, Takahashi teaches cold iron source (iron powder) and flux can be supplied together, as well as Takahashi further teaches iron source can be supplied in a two way through lance over the molten steel, or through the hopper.
Therefore, 35 U.S.C. § 102(a)(1) and 35 U.S.C. § 103 rejection of the claims have been maintained.
Conclusion
THIS ACTION IS MADE FINAL. 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 NAZMUN NAHAR SHAMS whose telephone number is (571)272-5421. The examiner can normally be reached M-F 8AM-4:00PM (EST).
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Merkling Sally can be reached on (571)2726297. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/NAZMUN NAHAR SHAMS/Examiner, Art Unit 1738
/SALLY A MERKLING/SPE, Art Unit 1738
Prosecution Insights