US20060169103A1 - Process for producing particulate iron metal - Google Patents

Process for producing particulate iron metal Download PDF

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US20060169103A1
US20060169103A1 US10/548,955 US54895505A US2006169103A1 US 20060169103 A1 US20060169103 A1 US 20060169103A1 US 54895505 A US54895505 A US 54895505A US 2006169103 A1 US2006169103 A1 US 2006169103A1
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slag
mgo
iron
containing substance
material mixture
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Shuzo Ito
Osamu Tsuge
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Kobe Steel Ltd
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Kobe Steel Ltd
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Assigned to KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) reassignment KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: ITO, SHUZO, TSUGE, OSAMU
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/008—Use of special additives or fluxing agents
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
    • C21B13/105—Rotary hearth-type furnaces
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
    • C22B1/16—Sintering; Agglomerating
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
    • C22B1/16—Sintering; Agglomerating
    • C22B1/22—Sintering; Agglomerating in other sintering apparatus
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B1/00—Preliminary treatment of ores or scrap
    • C22B1/14—Agglomerating; Briquetting; Binding; Granulating
    • C22B1/24—Binding; Briquetting ; Granulating
    • C22B1/242—Binding; Briquetting ; Granulating with binders
    • C22B1/244—Binding; Briquetting ; Granulating with binders organic
    • C22B1/245—Binding; Briquetting ; Granulating with binders organic with carbonaceous material for the production of coked agglomerates
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
    • C22B5/00—General methods of reducing to metals
    • C22B5/02—Dry methods smelting of sulfides or formation of mattes
    • C22B5/10—Dry methods smelting of sulfides or formation of mattes by solid carbonaceous reducing agents
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen

Definitions

  • the present invention relates to a manufacturing method for manufacturing granulated metallic iron, and particularly relates to an improved method for efficiently manufacturing high-quality granulated metallic iron with high productivity while reducing the concentration of sulfur as much as possible due to a carbon material such as coal in a method wherein a raw material mixture or a compact thereof containing an iron-oxide-containing substance such as iron ore or the like, and carbonaceous reducing agent such as a carbon material or the like, is subjected to solid state reduction by heating with a moving hearth-type reducing furnace while separating generated metallic iron from resultant slag, such that the generated metallic iron is coalesced in the form of grains, and is solidified by cooling, whereby the granulated metallic iron is completed.
  • the present inventors have proceeded with a study for improving a method for reducing the sulfur amount contained in the granulated metallic iron obtained in the aforementioned method, and as a result, it has been revealed that considerable desulfurizing effects can be obtained with a method wherein a suitable amount of a Ca-containing substance exhibiting desulfurizing effects due to high affinity for sulfur, e.g., CaCO 3 , is further added to the raw material mixture containing coal serving as a carbonaceous reducing agent as well as an iron-oxide-containing substance, and the aforementioned raw material mixture is reduced and melted by heating while suitably controlling heating temperature, atmosphere gas composition, and the like.
  • a suitable amount of a Ca-containing substance exhibiting desulfurizing effects due to high affinity for sulfur e.g., CaCO 3
  • a manufacturing method for granulated metallic iron wherein a raw material mixture containing an iron-oxide containing substance and a carbonaceous reducing agent is supplied onto a hearth of a moving hearth-type reducing furnace so as to be heated, the iron oxide contained in the raw material mixture is reduced with the carbonaceous reducing agent, and the generated metallic iron is coalesced in the form of grains while being separated from the resultant slag, following which the generated metallic iron is cooled so as to solidify, whereby granulated metallic iron is completed, the amounts of a CaO-containing substance, an MgO-containing substance, and a SiO 2 -containing substance, contained in the raw material mixture, are adjusted such that operation is performed with the slag basicity (CaO+MgO)/SiO 2 of 1.3 to 2.3, and with MgO-concentration of 5 to 13% by mass as to the slag composition, which are dependent upon the concentration of each of
  • an MgO-containing substance is preferably further blended to the raw material mixture so as to adjust the slag basicity and the MgO-concentration.
  • dolomite ore is employed as the MgO-containing substance.
  • a suitable amount of CaF 2 -containing substance is preferably further contained in the raw material mixture, exhibiting the advantage of adjusting the fluidity of the resultant slag.
  • the CaF 2 -containing substance is preferably contained in the raw material mixture with a CaF 2 -concentration of 0.2 to 2% by mass.
  • carbonaceous powder is preferably supplied so as to be spread over the hearth with thickness of 2 mm to 7.5 mm prior to supplying the raw material mixture to the moving hearth-type reducing furnace, effecting the advantage of maintaining high reduction potential within the furnace due to the action of the aforementioned carbonaceous powder, thereby improving desulfurization, and thereby obtaining granulated metallic iron with low sulfur concentration as well as improving the yield of the metallic iron.
  • manufacturing operation is preferably performed with the moving hearth-type reducing furnace under operation temperature of 1250 to 1550° C.
  • a suitable amount of an MgO-containing substance, which is to serve as a slag component, is aggressively included in said raw material mixture such that both the basicity (CaO+MgO)/SiO 2 of the resultant slag, and the MgO-concentration as to the slag composition, exhibit suitable ranges, suppressing an increase of sulfur concentration of manufactured granulated metallic iron, unavoidably occurring due to use of coal, coke, or the like, serving as a carbon material, thereby enabling manufacturing of high-quality granulated metallic iron with small sulfur concentration with high productivity.
  • FIG. 1 is a conceptual explanatory diagram which shows an example of a moving hearth-type reducing furnace employed in a manufacturing method according to the present invention
  • FIG. 2 is a chart which shows the relations between slag basicity (CaO+MgO)/SiO 2 and the melting point of the slag obtained from test results, wherein the curve (i) represents a case of employing only limestone for adjusting the slag basicity in the material mixture, and the curve (ii) represents a case of employing both the limestone and dolomite;
  • FIG. 3 is a chart which shows the relations between slag basicity (C+M)/S and the melting point of the slag obtained from another test, wherein the curve (i) represents a case of employing only limestone for adjusting the slag basicity in the material mixture, and the curve (ii) represents a case of employing both the limestone and dolomite;
  • FIG. 4 is a chart which shows the relations between the MgO-concentration in the slag and the sulfur partition ratio (S)/[S] in a case of employing dolomite for adjusting the slag basicity, wherein white circles represent the test results in a case of iron ore A, and solid circles represent the test results in a case of iron ore B;
  • FIG. 5 is a chart which shows the relation between the slag basicity (C+M)/S and the sulfur partition ratio (S)/[S] obtained from a test;
  • FIG. 6 is a chart which shows the relation between the slag basicity (C+M)/S and the sulfur partition ratio (S)/[S] obtained from another test.
  • FIG. 1 is a schematic diagram which shows an example of a moving hearth-type reducing furnace, wherein a rotary hearth furnace is employed, used in a method according to the present invention.
  • a material mixture (compacted simple green, or a compact such as a pellet, a briquette, or the like) 1 formed of an iron-oxide-containing substance and a carbonaceous agent, and if necessary, further formed of CaO, MgO, SiO 2 , or the like, contained as a matrix component or ash component, a binder, and a granulated carbonaceous substance 2 , preferably supplied so as to be spread over the hearth, is continuously supplied onto the hearth of a rotary hearth 4 through a material supply hopper 3 .
  • the powdery carbonaceous material 2 is supplied so as to be spread over the rotary hearth 4 through the material supply hopper 3 , following which the material mixture 1 is supplied so as to overlay the aforementioned powdery carbonaceous material 2 .
  • the material mixture 1 and the carbonaceous substance 2 are supplied through the single material supply hopper 3 , it is needless to say that an arrangement may be made wherein the material mixture 1 and the carbonaceous substance 2 are supplied through two or more hoppers 2 .
  • the carbonaceous substance 2 supplied so as to be spread over the hearth which is markedly effective in improving desulfurizing effect as well as improving reducing effects, may be omitted in some cases, as described later.
  • the rotary hearth 4 of the rotary hearth-type reducing furnace A is rotated counterclockwise normally with a cycle period of 8 to 16 minutes, depending upon operating conditions, and in the cycle period, the iron oxide contained in the material mixture 1 is reduced in solid state, and is coalesced in the form of grains due to lowering of melting point occurring due to carburizing, as well as separating generated metallic iron from resultant slag, whereby the granulated metallic iron is completed.
  • the reducing furnace A includes multiple combustion burners 5 on the upper side wall and/or the ceiling portion of the rotary hearth 4 so as to supply heat to the heath portion with combustion heat or radiant heat thereof from these burners 5 .
  • the material mixture 1 supplied onto the rotary hearth 4 formed of a refractory material is heated with combustion heat or radiant heat from the burners 5 while being rotationally moved within the reducing furnace A on the rotary hearth 4 , and the iron oxide contained in the material mixture 1 is reduced in solid state while passing through the heating band within the reducing furnace A, following which the generated metallic iron is coalesced in the form of grains while softening due to carburizing from the remaining carbonaceous reducing agent, as well as separating the generated metallic iron from the resultant molten slag, and the generated metallic iron is solidified by cooling in a downstream zone of the rotary hearth 4 , following which the generated metallic iron is discharged from the hearth with a discharge device 6 such as a screw.
  • reference character 7 denotes an exhaust gas duct.
  • a large-sized rotary hearth-type reducing furnace which is generally employed as a practice furnace has a configuration wherein fuel gas such as natural gas is burned with the multiple burners provided on the upper portion of the rotary hearth so as to supply combustion heat required for reducing and melting of the material mixture supplied on the hearth.
  • fuel gas such as natural gas
  • oxidizing gas such as CO 2 , H 2 O, and the like, contained in the exhaust gas generated due to the aforementioned combustion affects the atmosphere gas composition surrounding the material mixture, leading to considerable difficulty in maintaining high reduction potential of the atmosphere gas, which is represented by (CO+H 2 )/(CO+CO 2 +H 2 +H 2 O), and in many cases, which is also abbreviated to CO/(CO+CO 2 ).
  • the sulfur component contained in the coal, coke, or the like, serving as a carbonaceous reducing agent, added to the material mixture is fixed as CaS due to the CaO component contained in the slag, whereby the sulfur component is separated along with the slag.
  • the present inventors have revealed that in the event that the atmosphere gas has insufficient reduction potential at the time of reducing and melting, reaction of CaS and FeO occurs, each of which exist in an equilibrium manner, leading to a problem that the sulfur component is readily absorbed into the molten granulated metallic iron so as to form FeS. Accordingly, the present inventors made an intense study in order to obtain a method for maintaining high-level reduction potential of the atmosphere gas surrounding such a material mixture.
  • a method has been obtained as follows. That is to say, first, a carbonaceous powder layer is formed on the hearth of the reducing furnace beforehand, and the material mixture is supplied so as to overlay the aforementioned carbonaceous powder layer (which will be referred to as “carbonaceous powder layer spread over the hearth” hereafter), following which heating and reducing is performed.
  • the material mixture is supplied so as to overlay the aforementioned carbonaceous powder layer (which will be referred to as “carbonaceous powder layer spread over the hearth” hereafter), following which heating and reducing is performed.
  • high-level reduction potential of the atmosphere gas surrounding such a material mixture can be maintained as well as efficiently proceeding with reaction of reducing and melting in a short period in time of 10 to 16 minutes, which is a cycle period of the hearth of the rotary hearth-type reducing furnace, thereby relatively improving desulfurization.
  • the present inventors has revealed a method according to the present invention through an intense study, wherein a suitable amount of MgO is contained in the slag while suitably controlling the basicity (CaO+MgO)/SiO 2 , based upon concentration of CaO, MgO, and SiO 2 , contained in the material mixture, effecting desulfurization more efficiently in a step for reducing and melting, thereby markedly improving quality of the generated granulated metallic iron.
  • the supply amounts of the aforementioned CaO and MgO are adjusted such that the basicity (CaO+MgO)/SiO 2 of the composition of the slag is controlled in a range of 1.3 to 2.3 while maintaining the MgO-concentration of 5 to 13%, based upon the kind and the amount of the matrix component contained in the iron oxide (iron ore or the like) and the kind and the amount of the ash component contained in the carbonaceous reducing agent (coal, coke powder, or the like), contained in the material mixture, and furthermore, in some cases, the kind and the amount of the ash component contained in a CaO-containing substance or an MgO-containing substance, which may be additionally supplied, and the kind and the amount of the ash component contained in a carbonaceous powder which may be supplied so as to be spread on the hearth.
  • the supply amounts of a CaO-containing substance or MgO-containing substance, which are added separately from the material mixture, are adjusted based upon the matrix component contained in iron ore or the like supplied as an iron-oxide-containing substance, the composition and the concentration of the ash component contained in coal, coke, or the like supplied as a carbonaceous reducing agent, and furthermore, in some cases, the composition and the concentration of the ash component contained in carbonaceous powder which may be supplied so as to be spread over the hearth.
  • CaO-containing substance and MgO-containing substance are not restricted in particular, in the most general cases, calcium oxide or CaCO 3 is employed as a CaO-containing substance, and an MgO-containing substance extracted from natural ore including dolomite ore or seawater, is preferably employed.
  • the addition method employed in the present embodiment is not restricted in particular, rather, an arrangement may be made wherein the additional substances are added to the material mixture in the stage for adjusting the material mixture beforehand, or an arrangement may be made wherein the additional substances are supplied onto the rotary hearth beforehand along with or separately from the aforementioned carbonaceous powder which is to be supplied so as to be spread over the rotary hearth, and further, an arrangement may be made wherein the additional substances are added separately from the material mixture from the upper portion at the same time of or following supply of the material mixture, and so forth.
  • the sulfur partition ratio (S)/[S] is dependent upon equilibrium thereof which in turn is dependent upon the composition of the molten slag on the surface of the molten iron, the composition of the molten iron, and the atmosphere conditions.
  • the iron oxide in the material mixture is reduced with a carbonaceous reducing agent in the state of a solid under an atmosphere temperature of around 1250 to 1550° C.
  • the iron oxide is deoxidized, whereby reduced iron is obtained.
  • the most of the coal or coke contained in the material mixture is used in the stage of solid state reduction.
  • the sulfur contained in the coal or the like evaporates into the atmosphere, the most thereof is absorbed by the matrix component or the ash component contained in the material mixture, or CaO or the like contained in the additive material, leading to sulfur remaining in the material mixture in the form of CaS.
  • the reduced iron fine particles in the material mixture is subjected to rapid carburization by the remaining carbonaceous substance, i.e., carbon (C), leading to reduction of the melting point of the reduced iron as clearly shown in Fe—C phase diagram.
  • C carbon
  • the reduced iron subjected to carburization melts even at 1500° C. or less, for example, or even as low as 1350° C. or less, and the fine-particle reduced iron is coalesced, leading to the growth of large-sized granulated metallic iron.
  • slag components metal oxides which have not been reduced due to high affinity for oxygen, such as CaO, SiO 2 , Al 2 O 3 , MgO, and the like
  • the generated molten slag is coalesced, as well, leading to generally-complete separation of the slag from the granulated metallic iron coalesced due to melting and carburization.
  • the sulfur (S) mainly captured by CaO in the slag so as to form CaS is greatly affected by the reduction potential of the atmosphere gas surrounding the material mixture, even in the event of maintaining the same slag composition.
  • the reduction potential [CO/(CO+CO 2 )] of the atmosphere gas of around 0.7 or less it has been confirmed that in the event of the reduction potential [CO/(CO+CO 2 )] of the atmosphere gas of around 0.7 or less, a part amount or a considerable amount of the sulfur fixed in the form of CaS migrates to the reduced iron so as to form FeS.
  • iron is preferably not manufactured under an atmosphere temperature of 1550° C. or more, unlike the conventional iron-making or steel making furnaces wherein molten iron is reduced, from the perspective of the equipment and operation of the rotary hearth-type reducing furnace, and in this case, iron is preferably manufactured under an atmosphere temperature of around 1550° C. or less, and is more preferably manufactured under an atmosphere temperature of around 1500° C. or less.
  • adjustment of the slag generated in the aforementioned step of reducing and melting with increased basicity of 2.3 or more, inhibits coalescence of the reduced iron, as well as increasing the melting point of the slag, leading to inhibition of coalescence of the slag. This leads to difficulty in manufacturing large-sized granulated metallic iron with a high yield, which is contrary to the object of the present invention.
  • the composition of the material is adjusted such that the basicity (CaO+MgO)/(SiO 2 ), which will be also abbreviated to “(C+M)/S hereafter, is controlled in a range of 1.3 to 2.3 while maintaining the MgO-concentration of 5 to 13% contained in the slag, effecting remarked improvement of the sulfur partition ratio (S)/[S] between the slag and the granulated metallic iron, generated in the final stage, thereby greatly reducing the sulfur-concentration [S] remaining in the granulated metallic iron.
  • S sulfur partition ratio
  • S sulfur partition ratio
  • the sulfur partition ratio (S)/[S] has a strong relation with the slag basicity in the reaction between the slag and the metal in the ordinary iron making or steel making, as described above. Furthermore, it has been confirmed that the MgO indispensable for the manufacturing method according to the present invention has considerably poor desulfurization as compared with CaO. According to the present invention, a considerable amount of MgO is aggressively used along with CaO, and as a result, the manufacturing method according to the present invention has the advantage of drastically improved desulfurizing effects as compared with a method of employing only CaO.
  • the relation between the slag basicity (C+M)/S generated in the final stage and the melting point is considerably dependent upon the kind and brand of the iron-oxide-containing substance (iron ore or the like) and the carbonaceous reducing agent (coal or coke) serving as raw materials.
  • FIG. 2 shows research results of the relation between the basicity (C+M)/S of the generated slag and the melting point in a case of the process of reducing and melting with a rotary hearth-type reducing furnace using a material mixture formed of hematite ore (A) (see Table 1 in the Example described later), which is a typical example of an iron-oxide-containing substance, coal (see Table 2 in the Example described later) serving as a carbonaceous reducing agent, each of which serve as main raw materials, and further containing limestone serving as a CaO-containing substance, and dolomite serving as an MgO-containing substance for adjusting the basicity of the slag in the final stage.
  • A hematite ore
  • the melting point of the slag is calculated from the phase diagrams based upon a quaternary system formed of CaO, SiO 2 , Al 2 O 3 , and MgO, serving as principal components of the slag.
  • the curve (i) in the drawing represents the relation between the slag basicity and the melting point in a case of supplying only limestone, which is a CaO-containing substance, as a basicity adjusting agent.
  • the slag basicity (C+M)/S exceeding approximately 1.4 causes a rapid increase of the melting point of the slag.
  • the slag basicity (C+M)/S of around 1.75 causes the melting point of the slag to reach approximately 1550° C., which is assumed to be the maximal temperature permissive for actual practical operation. Furthermore, the slag basicity (C+M)/S exceeding around 1.75 causes the melting point of the slag to exceed 1550° C., which is beyond the range permissive for the manufacturing method according to the present invention. Accordingly, in the event of maintaining the atmosphere temperature, melting and coalescence of the resultant slag is inhibited, leading to difficulty in coalescence of reduced iron, which is contrary to the object of the present invention. It is needless to say that manufacturing at an increased atmosphere temperature (operating temperature) exceeding 1550° C.
  • the curve (ii) shown in FIG. 2 represents the relation between the slag basicity (C+M)/S and the melting point in a case of supplying both limestone and dolomite as basicity-adjusting agents.
  • an increase of the MgO concentration in the slag in the final stage causes reduction of the melting point of the slag in the final stage over the entire range of the slag basicity as compared with the curve (i).
  • addition of a suitable amount of an MgO-containing substance to the material mixture suppresses the melting point of the slag in the final stage to 1550° C. or less, even in the event that the basicity (C+M)/S of the slag is increased up to around 2.3, thereby enabling operation without problems under the atmosphere temperature of 1550° C. which leads to problems in a case of FIG. 1 .
  • manufacturing is made with a practical-scale moving hearth-type reducing furnace with increased basicity (C+M)/S of the slag in the final stage up to around 2.3, which is the maximal permissive basicity, using an MgO-containing substance serving as a basicity-adjusting agent, sufficient for melting the slag under an atmosphere temperature up to 1550° C. which matches the need for practical operation, thereby stably manufacturing granulated metallic iron under stable operation situations while maintaining the sulfur partition ratio (S)/[S] between the slag and the metal of around 25 or more, and preferably maintaining that of 35 or more.
  • C+M basicity
  • S sulfur partition ratio
  • the granulated metallic iron can be obtained in the final stage in a sure manner with a sulfur concentration of 0.05% or less, and preferably with a sulfur concentration of 0.04 or less, somewhat depending upon the brand of the coal or the like supplied as a carbonaceous reducing agent or a material supplied so as to be spread over the hearth.
  • the manufacturing method according to the present invention has a significant advantage of preventing reduction of the sulfur partition ratio (S)/[S] due to deterioration in the reduction potential of the atmosphere gas by adjusting the slag basicity (C+M)/S and the Mg-concentration, which is unavoidable in a case of employing a combustion heating method using gas burners most generally employed as the heating method for a practical furnace.
  • the slag basicity (C+M)/S is preferably determined to be in a range of 1.4 to 2.0.
  • FIG. 3 shows the relation between the slag basicity (C+M)/S and the melting point of the slag, wherein the generated slag basicity (C+M)/S is controlled by adjusting the addition amount of a CaO-containing substance and an MgO-containing substance, added to the material mixture mainly formed of magnetite ore serving as an iron-oxide-containing substance and coal serving as a carbonaceous reducing agent shown in Table 2 described later in the same way as in FIG. 2 described above.
  • the slag basicity (C+M)/S of around 1.5 or less causes the melting point of the slag of 1550° C., as can be clearly understood from the curve (i) in the drawing.
  • the increase of the MgO-concentration of the slag prevents rapid increase of the melting point of the slag due to an increase of the slag basicity, as can be clearly understood from the curve (ii).
  • the melting point of the slag is suppressed to 1550° C. or less.
  • FIG. 4 shows the research results of the relation between the MgO-concentration of the slag and the sulfur partition ratio (S)/[S], obtained with the manufacturing method according to the present invention.
  • S sulfur partition ratio
  • FIG. 4 shows the test results for the two kinds of the material mixtures using iron ore A and iron ore B, respectively, serving as iron-oxide-containing substances. While these test results exhibit somewhat of a difference therebetween due to the properties of the material, the test results exhibit generally the same nature.
  • the sulfur partition ratio (S)/[S] exhibits a high value of 25 or more with the MgO-concentration in a range of 5 to 13%, thereby exhibiting the advantage of reduction of sulfur component in the reduced iron. While the detailed mechanism is unclear at present, it is assumed that the slag composition is contained in the supplied material in a complicated way, which affects the sulfur partition ratio (S)/[S].
  • the suitable MgO-concentration in the slag is determined to be in a range of 5 to 13% so as to effect the sulfur partition ratio (S)/[S] of 0.25 or more based upon the test results using these typical two kinds of iron ore (A) and (B).
  • the slag basicity (C+M)/S calculated based upon the slag composition contained in all of the used raw material, and the MgO-concentration of the slag are suitably adjusted so as to suitably control the melting point of the generated slag and the sulfur partition ratio (S)/[S], for an iron-oxide-containing substance, a carbonaceous reducing agent, and the like, used in the present manufacturing method.
  • the reaction exhibits the basic nature that the increased basicity (C+M)/S causes gradual deterioration in coalescence of the reduced-iron fine particles generated due to the iron-oxide-containing substance being subjected to reduction in the material mixture, even with the slag basicity (C+M)/S of 2.3 or less.
  • a slag basicity (C+M)/S which exceeds 2.3 contributes to deterioration in coalescence of the slag, leading to deterioration in coalescence of the generated reduced-iron particles, as well, and leading to difficulty in obtaining large-sized granulated metallic iron with the high yield, which is the object of the present invention.
  • large-sized granulated metallic iron which is the object of the present invention needs to be manufactured with as high a yield as possible, even in a case of the slag basicity (C+M)/S of 2.3 or less in the final stage.
  • the present inventors have revealed a method for suppressing deterioration in the yield of the granulated metallic iron with suitable particle size due to increased slag basicity (C+M)/S through intense study. That is to say, addition of a suitable amount of a CaF 2 -containing substance, e.g., fluorite, to the material mixture improves fluidity as well as reducing the melting point of the generated slag, thereby effecting improvement of coalescence of the slag, as well as improving coalescence of the reduced iron particles, thereby significantly improving the yield of the large-sized granulated metallic iron.
  • a suitable amount of a CaF 2 -containing substance e.g., fluorite
  • the aforementioned CaF 2 -containing substance should be supplied with a CaF 2 -concentration of 0.2% or more as to all of the slag composition, and preferably 0.4% or more, in order to efficiently exhibit the advantages due to the supply of such a CaF 2 -containing substance with a practical scale.
  • CaF 2 is added to the material mixture with CaF 2 -concentration of 0.2% or more as to the slag composition so that the increased CaF 2 concentration compensates for deterioration in fluidity due to increased slag basicity (C+M)/S, thereby enabling stable manufacturing of large-sized granulated metallic iron with the high yield.
  • the concentration of the CaF 2 -containing substance is preferably suppressed to 2.0% or less as to the whole of the slag composition, and is more preferably suppressed to 1.5% or less.
  • the basicity (C+M)/S of the generated slag and the MgO concentration are determined as described above, which is the most essential component according to the present invention.
  • the carbonaceous material supplied so as to be spread over the hearth is not indispensable, the aforementioned supply of the carbonaceous material is preferable in order to more efficiently improve the reduction potential in the furnace, thereby more efficiently improving both the advantages of high yield of the metallic iron and reduction of sulfur concentration thereof.
  • a powder carbonaceous material is preferably supplied so as to be spread over the hearth with a thickness of around 2 mm in order to exhibit such an advantage in a sure manner.
  • the carbonaceous material spread over the hearth serves as a buffer between the raw material mixture and the hearth formed of a refractory material, and furthermore serves as a protector for the hearth, thereby improving the lifespan of the hearth.
  • the thickness of the aforementioned carbonaceous material spread over the hearth is preferably suppressed to around 7.5 mm or less.
  • the kind of the aforementioned carbonaceous material spread over the hearth is not restricted in particular, and an arrangement may be employed wherein ordinary coal or coke is crushed, and preferably adjusted so as to exhibit a suitable grain size.
  • anthracite is preferably employed for the reason of exhibiting low fluidity, low expansion, and low adhesion, on the hearth.
  • raw material compacts in the form of pellets were formed of iron ore serving as an iron-oxide-containing substance, coal serving as a carbonaceous reducing agent, and additional material for adjusting the slag basicity such as limestone (CaCO 3 ), dolomite (CaCO 3 .MgCO 3 ), or the like, and if necessary, a suitable amount of fluorite (CaF 2 ), and furthermore, a small amount of wheat flour serving as a binder.
  • iron ore A and B are employed as shown in Table 1.
  • the composition of the coal serving as a carbonaceous reducing agent is shown in Table 2.
  • the aforementioned raw material compacts were continuously supplied into the small-sized experimental rotary hearth-type reducing furnace so as to be subjected to heating and reduction.
  • the respective temperatures of the heating reduction zone and the carburizing melting zone were set in a range of 1400 to 1470° C. by heating from the burners.
  • the iron-oxide component contained in the material compact supplied onto the hearth of the rotary hearth-type reducing furnace was subjected to reduction in the form of a solid while passing around through the heating region within the furnace in a cycle period of around 10 to 16 minutes.
  • the generated reduced iron was subjected to carburization due to the remaining carbonaceous substance in the latter stage of reduction in the reducing furnace, leading to reduction of the melting point, and leading to coalescence of the reduced iron.
  • part or all of the resultant slag melts, leading to coalescence of the slag, as well, thereby enabling separation of molten granulated metallic iron from the molten slag.
  • these molten granulated metallic iron and molten slag are cooled down to the melting point or less (specifically, cooled down to around 1100° C.) so as to solidify in the final stage in the rotary hearth-type reducing furnace, following which the granulated metallic iron and the slag in the form of a solid are discharged outside from the furnace.
  • FIG. 5 shows the test results in a case of employing the iron ore (A), i.e., hematite, wherein the horizontal axis represents the basicity (C+M)/S of the generated slag, and the vertical axis represents the sulfur partition ratio (S)/[S] obtained from the analysis values of sulfur by measuring the sulfur concentration of the obtained granulated metallic iron and the resultant slag.
  • A iron ore
  • S sulfur partition ratio
  • manufacturing is preferably made while maintaining the sulfur partition ratio (S)/[S] of 25 or more, more preferably, 30 or more, in order to preferably suppress the sulfur concentration of the obtained granulated metallic iron to 0.05% or less, and more preferably 0.04% or less.
  • the increased slag basicity (C+M)/S of around 1.7 in the final stage causes an increase of the melting point of the slag so coalescence of the molten slag occurs less readily, leading to inhibition of coalescence of reduced iron.
  • a great number of fine granulated metallic iron particles are generated, leading to difficulty in obtaining large-sized granulated metallic iron with the high yield.
  • slag basicity (C+M)/S of 1.7 or more without supplying the MgO-containing substance addition of a CaF 2 -containing substance with the CaF 2 concentration of 0.2% or more, preferably 0.4% or more, as to the slag composition, improves the fluidity of the slag as well as reducing the melting point of the slag again, thereby obtaining large-sized granulated metallic iron with the high yield.
  • FIG. 6 shows the test results in a case of employing magnetite ore as an iron-oxide-containing substance, obtained in the test performed in the same way as in a case of employing hematite as described above, which exhibits generally the same nature as shown in FIG. 5 .
  • the increased slag basicity (C+M)/S of 1.2 or more causes a rapid increase of the sulfur partition ratio (S)/[S]. While there is no clear difference between the test results in the present example and the test results shown in FIG.
  • addition of an MgO-containing substance to the raw material mixture is adjusted beforehand such that the slag basicity (C+M)/S exhibits 1.3 or more, preferably 1.4 or more, in the final stage, effecting high desulfurization, thereby suppressing the sulfur concentration in the granulated metallic iron to 0.05% or less, and more preferably 0.04% or less.
  • the granulated metallic iron can be generated with sulfur concentration [S] of 0.05% or less, more preferably 0.04% or less, by suitably adjusting an MgO-containing substance in the raw material mixture such that the slag basicity (C+M)/S exhibits a range of 1.3 to 2.3 in the final stage, and the MgO-concentration in the slag exhibits a range of 5 to 13%, which is dependent upon the respective concentration of the CaO, MgO, and SiO 2 , contained in the material mixture.
  • S sulfur concentration

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US20110023657A1 (en) * 2007-09-14 2011-02-03 Tetsuharu Ibaraki Process for producing reduced iron pellets, and process for producing pig iron
US20110023656A1 (en) * 2008-04-09 2011-02-03 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd.) Method for producing granular metallic iron
US20110024681A1 (en) * 2008-04-10 2011-02-03 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) Titanium oxide-containing agglomerate for producing granular metallic iron
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Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4364771A (en) * 1979-05-15 1982-12-21 Societe Francaise D'electrometallurgie Sofrem Product for the desulphurization of cast irons and steels
US4981510A (en) * 1988-08-06 1991-01-01 Fried.Krupp Gesellschaft Process and apparatus for the production of ferrochromium
US5575829A (en) * 1995-06-06 1996-11-19 Armco Inc. Direct use of sulfur-bearing nickel concentrate in making Ni alloyed stainless steel
US5749939A (en) * 1996-12-04 1998-05-12 Armco Inc. Melting of NI laterite in making NI alloyed iron or steel
US6149709A (en) * 1997-09-01 2000-11-21 Kabushiki Kaisha Kobe Seiko Sho Method of making iron and steel
US6270552B1 (en) * 1997-09-30 2001-08-07 Kawasaki Steel Corporation Rotary hearth furnace for reducing oxides, and method of operating the furnace
US20010027701A1 (en) * 2000-03-30 2001-10-11 Midrex International B. V. Method of producing metallic iron and raw material feed device
US6413295B2 (en) * 1998-11-12 2002-07-02 Midrex International B.V. Rotterdam, Zurich Branch Iron production method of operation in a rotary hearth furnace and improved furnace apparatus
US6592649B2 (en) * 2000-06-28 2003-07-15 Midrex International B.V. Zurich Branch Method of producing iron nuggets
US6602320B2 (en) * 2000-04-10 2003-08-05 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Method for producing reduced iron
US6749664B1 (en) * 2001-01-26 2004-06-15 Midrex International, B.V., Rotterdam, Zurich Branch Furnace hearth for improved molten iron production and method of operation
US20040154436A1 (en) * 2001-06-18 2004-08-12 Shuzo Ito Method for producing granular metal

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH1068011A (ja) * 1996-08-26 1998-03-10 Sumitomo Metal Ind Ltd 酸化物分散鋼の製造方法
JP4691827B2 (ja) * 2001-05-15 2011-06-01 株式会社神戸製鋼所 粒状金属鉄

Patent Citations (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4364771A (en) * 1979-05-15 1982-12-21 Societe Francaise D'electrometallurgie Sofrem Product for the desulphurization of cast irons and steels
US4981510A (en) * 1988-08-06 1991-01-01 Fried.Krupp Gesellschaft Process and apparatus for the production of ferrochromium
US5575829A (en) * 1995-06-06 1996-11-19 Armco Inc. Direct use of sulfur-bearing nickel concentrate in making Ni alloyed stainless steel
US5749939A (en) * 1996-12-04 1998-05-12 Armco Inc. Melting of NI laterite in making NI alloyed iron or steel
US6149709A (en) * 1997-09-01 2000-11-21 Kabushiki Kaisha Kobe Seiko Sho Method of making iron and steel
US6270552B1 (en) * 1997-09-30 2001-08-07 Kawasaki Steel Corporation Rotary hearth furnace for reducing oxides, and method of operating the furnace
US6413295B2 (en) * 1998-11-12 2002-07-02 Midrex International B.V. Rotterdam, Zurich Branch Iron production method of operation in a rotary hearth furnace and improved furnace apparatus
US20010027701A1 (en) * 2000-03-30 2001-10-11 Midrex International B. V. Method of producing metallic iron and raw material feed device
US6630010B2 (en) * 2000-03-30 2003-10-07 Midrex International B.V. Zurich Branch Method of producing metallic iron
US6602320B2 (en) * 2000-04-10 2003-08-05 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Method for producing reduced iron
US6592649B2 (en) * 2000-06-28 2003-07-15 Midrex International B.V. Zurich Branch Method of producing iron nuggets
US6749664B1 (en) * 2001-01-26 2004-06-15 Midrex International, B.V., Rotterdam, Zurich Branch Furnace hearth for improved molten iron production and method of operation
US20040154436A1 (en) * 2001-06-18 2004-08-12 Shuzo Ito Method for producing granular metal

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7674316B2 (en) 2001-07-12 2010-03-09 Midrex International B.V. Zurich Branch Method for producing metallic iron
US20090031859A1 (en) * 2001-07-12 2009-02-05 Midrex International B. V. Zurich Branch Method for producing metallic iron
US20040173054A1 (en) * 2001-07-12 2004-09-09 Osamu Tsuge Method of manufacturing metal iron
US20040168550A1 (en) * 2001-07-24 2004-09-02 Osamu Tsuge Method for accelerating separation of granular metallic iron from slag
US20100164150A1 (en) * 2004-12-07 2010-07-01 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US7695544B2 (en) 2004-12-07 2010-04-13 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US8158054B2 (en) 2004-12-07 2012-04-17 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US7628839B2 (en) 2004-12-07 2009-12-08 Iwao Iwasaki Method and system for producing metallic iron nuggets
US7632335B2 (en) 2004-12-07 2009-12-15 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US20060150775A1 (en) * 2004-12-07 2006-07-13 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US20060150773A1 (en) * 2004-12-07 2006-07-13 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US20060150774A1 (en) * 2004-12-07 2006-07-13 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US7641712B2 (en) * 2004-12-07 2010-01-05 Nu-Iron Technology, Llc Method and system for producing metallic iron nuggets
US8097065B2 (en) 2006-10-04 2012-01-17 Nu-Iron Technology, Llc System and method for producing metallic iron
US20090229414A1 (en) * 2006-10-04 2009-09-17 Nu-Iron Technology, Llc System and method for producing metallic iron
US8535602B2 (en) 2006-10-04 2013-09-17 Nu-Iron Technology, Llc System and method for producing metallic iron
US20100171072A1 (en) * 2007-06-27 2010-07-08 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Method for manufacturing granular metallic iron
US20110023657A1 (en) * 2007-09-14 2011-02-03 Tetsuharu Ibaraki Process for producing reduced iron pellets, and process for producing pig iron
US9034074B2 (en) * 2007-09-14 2015-05-19 Nippon Steel & Sumitomo Metal Corporation Process for producing reduced iron pellets, and process for producing pig iron
US20110023656A1 (en) * 2008-04-09 2011-02-03 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel Ltd.) Method for producing granular metallic iron
US20110024681A1 (en) * 2008-04-10 2011-02-03 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd) Titanium oxide-containing agglomerate for producing granular metallic iron
US20150361515A1 (en) * 2013-02-28 2015-12-17 Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) Method for producing reduced iron agglomerate
US10683562B2 (en) 2015-05-28 2020-06-16 Kobe Steel, Ltd. Reduced iron manufacturing method

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KR20050109589A (ko) 2005-11-21
RU2005132303A (ru) 2006-02-10
BRPI0408562A (pt) 2006-03-21
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AU2004221565A1 (en) 2004-09-30
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ATE539173T1 (de) 2012-01-15
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EP1605067A4 (en) 2008-03-12
EP1605067B1 (en) 2011-12-28

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