JP2000119720A - Method and device for charging iron-making dust into smelting reduction furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for making inexpensive equipment as the molten iron producing technique in a substitution of a blast furnace method by utilizing the sensible heat of gas in a smelting reduction furnace and reducing the consumption of oxygen and the generating quantity of gas. SOLUTION: Iron-making dust containing moisture, single or together with ore, carbonaceous material, waste synthetic resin material or slag-making material, is exposed for a prescribed time in the high temp. atmosphere in the furnace or in a duct and after drying the moisture, and is charged into the bath part 71. In this furnace, a charged material staying position is formed. The dust can be charged with slurry 41. At this time, a shape-strengthening material for holding a necessary shape, is mixed or the slurry is coated with the shape-strengthening material and can be formed as bar-state. The staying time of the charged material according to raising/lowering of the bath temp. and heat load information of the furnace wall, and the charging position distribution in the horizontal cross section in the furnace, are adjusted. For example, the necessary staying time tr for drying the wet iron-making dust is tr=5W/S (wherein, W: the moisture ratio in the iron-making dust (outer content) S: the specific surface area of the iron-making dust ≡ α/dρ(m2/t) and α, d and ρ: the shape coefficient, typical diameter and bulk density of the iron-making dust, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an iron making method which does not rely on the blast furnace method. In the process of melting and reducing iron ore to produce hot metal, secondary combustion of carbon material with an oxygen-containing gas is performed. In the process of continuous smelting reduction smelting of oxide ore with, in order to reduce oxygen consumption and process gas generation and provide equipment with low equipment cost, raw materials including ironmaking dust to smelting reduction furnace and The present invention relates to a method and an apparatus for supplying fuel.

[0002]

2. Description of the Related Art Generally, hot metal is produced by a blast furnace method. The blast furnace method requires coke and sinter, and operation of the coke oven and sintering machine is indispensable. However, its operating environment is severely restricted. In the future, it is expected that there will be a shortage of resources of coking coal, and that from a global perspective, iron sources and scrap are unevenly distributed. Therefore, a hot metal production process in which steam coal and fine iron ore are directly used and a preliminary reduction furnace and an iron bath type smelting reduction furnace are directly connected, that is, a smelting reduction iron making method is being studied. As a typical process of the smelting reduction iron making method, a DIOS method (Direct Iron Ore Smelting®) is used.
eduction Process). The basis of this method is to obtain hot metal by subjecting a carbon material to secondary combustion with an oxygen-containing gas and continuously smelting and reducing smelting of iron ore using the heat.

[0003] The problems to be solved in the smelting reduction steelmaking method are wide-ranging, but when introducing the smelting reduction steelmaking method to a number of steel mills other than the so-called integrated pig steel maker, that is, from a blast furnace facility to a rolling mill, that is, a mini mill. Therefore, there is a need for a smelting reduction process that reduces the amount of oxygen required for smelting reduction smelting of iron ore and the amount of gas generated therefrom, and that has low equipment costs.

The DIOS method is disclosed, for example, in "Recent Trends in New Iron Sources" (Iron Process Forum of the Iron and Steel Institute of Japan, September 29, 1996, pp. 42-51) (hereinafter, "prior art"). 1 ").

FIG. 12 shows a main part of a process flow of a pilot plant of the smelting reduction iron making method according to Prior Art 1. According to this, the powdery ore 76 is preheated in the preheating furnace 77, the preheated ore 76 'is charged into the fluidized bed type prereduction furnace 2, preheated to 700 to 800C, and preheated to about 20%. The reduced pre-reduced ore 76 "is charged into an iron bath type smelting reduction furnace 1. Since a fluidized bed is employed as the pre-reduction furnace 2, the particle size of the iron ore 76 charged therein is determined by a shaft furnace. The iron ore has a particle size of-
There is an advantage that a so-called sinter feed in the form of small particles or powder having a size of about 8 mm or less can be used.

[0006]

The above prior art has the following problems. As in Prior Art 1,
In combination with the smelting reduction furnace of the secondary combustion type, the ultimate reduction rate of iron ore cannot thermodynamically exceed 33%, the unit consumption of coal is 700 kg / t or more, and the unit consumption of oxygen is almost 500 Nm ³ /. t or more, the sensible heat and latent heat of the generated gas are 1 to
2 Gcal / t. As described above, the scale of an oxygen plant or a gas processing / energy conversion plant for establishing a process with a large unit consumption of working materials becomes extremely large. In addition, since ore, coal, auxiliary raw materials and the like are used by being charged into a closed furnace, it is necessary to avoid the iron ore and the like from adhering or clogging in the charging system. Therefore, it is necessary to dry them before putting them into a closed furnace, and the amount of steam required for that purpose reaches several hundred kg / t, which causes an increase in equipment cost ( Problem 1).

[0007] The smelting reduction steelmaking method is very excellent in that the raw materials and fuels that can be used are flexible as described above. However, the cost of drying equipment is enormous in order to use low-quality, high-moisture-content coal ranging from lignite to lignite-blue coal, and low-quality, high-moisture ore ranging from limonite to hydroxide hydroxide. It is problematic to use them commercially.

In order to improve such a problem, Japanese Patent Application Laid-Open No. Hei 6-271919 discloses the following technique (hereinafter referred to as "prior art 2"). That is, the ore and the coal are preliminarily treated in another furnace to obtain a high reduction ore. By using this, the unit consumption of various raw materials is reduced. However, there is a problem that a new furnace such as a rotary kiln needs to be newly constructed. Drying is also required when charging raw materials into a furnace for pretreatment. In the rotary kiln type furnace, the treatment temperature is limited to 500 ° C. to 900 ° C., and the treatment at a high temperature of 1200 ° C. or more to promote metallization of ore and remove volatile matter in coal is mentioned. I haven't.

Further, a flow for introducing the smelting reduction furnace gas into the rotary kiln is shown. However, in the smelting reduction furnace, the degree of gas oxidation in the furnace, that is, (CO ₂ + H ₂ O) /
When the secondary combustion operation is performed when (CO + CO ₂ + H ₂ + H ₂ O) × 100% is 25% or more, the heat load on the furnace wall is large, the ambient temperature immediately above the bath is about 1800 ° C.,
Since the temperature may exceed 2000 ° C. in some cases, a refractory cannot withstand the fire resistance of the structure, and the structure must be a water-cooled structure. Further, in this case, in order to suppress the obstruction of the furnace port due to scattering, adhesion and deposition of the molten slag, several m of the furnace wall height are required.
The above water cooling of the furnace body is essential. Therefore, heat loss from the high-temperature gas to the water-cooled structure becomes extremely large. Therefore, in the case of the prior art 2, 1000 is required for the rotary kiln.
Since the gas whose temperature has been lowered to about ℃ is introduced, it is inefficient from the viewpoint of effectively utilizing the sensible heat of the smelting reduction furnace gas (problem 2).

Japanese Patent Application Laid-Open No. 4-32505 discloses a method in which compression-molded coal is introduced into a smelting reduction furnace, and Japanese Patent Application Laid-Open No. 3-287708 discloses a method in which a mixture obtained by mixing and molding fine coal and fine ore is introduced into a smelting reduction furnace. The aim is to suppress the scattering of raw materials and fuel and to stably improve the secondary combustion rate ("Prior Art 3" and "Prior Art 4", respectively). However, this method has not basically been a drastic solution to the above problem. However, if the ore or coal is handled in the form of a slurry, the transportation is easy and there is no problem of dust generation. On the other hand, when raw materials and fuels with a high water content are directly introduced into the smelting reduction furnace, not only evaporation of water, but also decomposition and endothermic reaction of water with carbonaceous materials, etc. This leads to a significant increase in units, which is undesirable (problem 3).

Here, the thickness of the molded product is tested at 7 mm, but it is considered that a larger thickness is desirable in consideration of the strength and the pulverization when the coal particle size is large. In addition, the operation of injecting slurry-like ore into the preliminary reduction furnace is not desirable because local unstable operation such as local temperature drop and agglomeration occurs, which hinders continuous stable operation (problem 4).

In the prior arts 1, 3 and 4, the contact time between the charge and the smelting reduction furnace gas is as short as several seconds at most.
With the usual particle size of the charge, no improvement such as evaporation of water from the charge or devolatilization of the carbon material could be expected. The contact time with the gas takes only a few seconds even if it falls freely, and it becomes even shorter when pneumatically or injected, even if the charging position is in the hood or duct above the smelting reduction furnace,
Contact with the gas is hardly long. When the raw materials and fuel are charged, the heat exchange and reaction between the gas and the raw fuel cannot be expected except for fine ones of 1 mm or less (problem 5).

[0013] Accordingly, an object of the present invention is to solve or avoid the above-mentioned problems, and to use the sensible heat of a smelting reduction furnace gas as a hot metal production technique instead of the blast furnace method, using the sensible heat of smelting reduction furnace gas. And reduce the amount of gas generated and utilize this as much as possible, thus reducing equipment costs.
An object of the present invention is to provide a smelting reduction smelting method for metals.

[0014]

In view of the above, the present inventors have conducted intensive studies to develop a smelting reduction smelting method for metals. That is, the test results on Prior Art 1 were examined in detail, and experiments were repeated. The present invention has solved the problem by utilizing the sensible heat of the gas generated by the smelting reduction furnace without newly adding a furnace, and in particular, in order to effectively utilize various ironmaking dusts at low cost. The summary is as follows.

According to a first aspect of the present invention, there is provided a method for charging iron-making dust into a smelting reduction furnace, wherein the iron-making dust containing water, ore, carbonaceous material, waste synthetic resin material, A method of charging a charge comprising a mixture containing at least one selected from slag-making materials into the smelting reduction furnace, wherein the charge is previously formed into a slurry state, Is mixed with a shape-enhancing substance for holding and strengthening the shape of the slurry, or the slurry is coated with a shape-enhancing thin plate-like material to form a rod or plate, and the thus obtained charge slurry is subjected to the smelting reduction. During the smelting in the furnace,
The smelting reduction furnace is characterized in that it is charged into a bath of the smelting reduction furnace while exposing a high-temperature gas generated from the smelting reduction furnace to an atmosphere in the smelting reduction furnace. Thus, the moisture and volatile components of the charge to the smelting reduction furnace are evaporated.

Here, the term "rod-shaped or plate-shaped" means a form suitable for staying and contacting in a high-temperature atmosphere in a furnace for a predetermined time and desirably having a large specific surface area. I do. From this point of view, a rod or plate is
As the slurry is pumped downward from the inlet, the cross-sectional shape may be broad, including circles, ellipses, squares, rectangles, and the like, suspended in the longitudinal direction, and fed into the furnace as a substantially continuous body. It shall broadly include forms. Hereinafter, in this specification, the term rod-shaped or plate-shaped all refers to the same form.

According to a second aspect of the present invention, there is provided a method for charging ironmaking dust into a smelting reduction furnace, wherein ironmaking dust is charged into the smelting reduction furnace in a step of smelting ore in the smelting reduction furnace. during smelting in the reduction furnace, to the smelting reduction furnace atmosphere of the hot gas generated from the smelting reduction furnace, the iron dust containing water, wherein: t _r = 5W / S, where, t _r: retention time (Min) W: water content of iron dust containing water (external number) (-) S: specific surface area of iron dust containing water ≡α / (d)
ρ) (m ² / t) α: Shape factor of iron dust containing water (−) d: Representative diameter of iron dust containing water (m) ρ: Bulk density of iron dust containing water (t / after a residence time t _r or represented by m ^3), a steel dust thus removed water in which characterized in that charged into the bath portion of the smelting reduction furnace.

Here, the representative diameter d of the iron dust containing water is defined as a value at a certain point in time when the iron dust is retained in the furnace atmosphere until the iron dust is charged into the bath of the smelting reduction furnace.
When one side of the ironmaking dust is not in contact with the atmosphere, it refers to the depth from the contact surface to the non-contact surface of the ore, and is also rod-like, cord-like, granular, massive, disk-like, spherical,
In the case where the ellipsoidal shape or the outer periphery of the ore itself is included in the atmosphere inside the furnace, it refers to the minor diameter of the ore. At this time, when the particles of the raw material are agglomerated due to moisture or the like, or when the particles are intentionally agglomerated, it refers to the minor diameter of the aggregate thus formed. Hereinafter, the definitions of the other representative diameters are based on this.

Regarding the shape factor α, the simple substance of the raw material to be measured having the representative diameter d is α = 6 in the case of a sphere, α = 4 in the case of a column or a rod, and is in the form of a plate. In the case of deposition, that is, when one surface of the plate-shaped body is in contact with the atmosphere and the other surface is not in contact with the atmosphere, α = 1. In addition, even if it is plate-like, when both surfaces of the plate-like body are in contact with the atmosphere, α = 2.

According to a third aspect of the present invention, there is provided a method for charging ironmaking dust into a smelting reduction furnace, wherein ironmaking dust is charged into the smelting reduction furnace in a step of smelting ore in the smelting reduction furnace. During smelting in the reduction furnace, the atmosphere in the smelting reduction furnace of the high-temperature gas generated from the smelting reduction furnace contains iron-containing dust containing water, ore, carbonaceous material, waste synthetic resin material and slag material. One or more selected types are mixed in advance, and this mixture is represented by the formula: _tr = 5 W / S, where _tr : residence time (min),
W: water content of the mixture (wt.%), S: specific surface area of the mixture {α _i / (d _i p _i )} x
_i (m ² / t), where i: a suffix representing each component of the mixture, x _i : weight ratio (−) of each component of the mixture,
alpha _i: mixtures shape factor of the constituent material (-), d _i: representative size of the mixture the constituent material (m), ρ _i: time t _r indicated by the bulk density of the mixture the constituent material (t / m ³⁾ After the stagnation, the mixture from which water has been removed is charged into a bath of the smelting reduction furnace.

According to a fourth aspect of the present invention, there is provided a method for charging ironmaking dust into a smelting reduction furnace according to the second or third aspect, wherein the substance to be charged into the smelting reduction furnace is charged in a slurry state. It is characterized by the following. Here, the representative diameter d of the iron-containing dust containing water or the representative diameter of each constituent material of the mixture represents the representative diameter in the slurry state.

According to a fifth aspect of the present invention, there is provided a method for charging ironmaking dust into a smelting reduction furnace according to the fourth aspect, wherein the charged material in the slurry state is used for maintaining the slurry in a required shape. It is preferable to mix a shape-enhancing substance, or to coat the outer periphery of the charge in a slurry state with a shape-enhancing thin plate-like material into a rod-like or plate-like shape, with a gas vent hole through which water vapor or the like passes. The present invention is characterized in that the slurry is formed.

According to a sixth aspect of the present invention, there is provided a method for charging iron-making dust into a smelting reduction furnace according to any one of the first to fifth aspects of the present invention, wherein each of the above-mentioned substances is used as the substance charged into the smelting reduction furnace. It is characterized in that a single element having a representative diameter within a range of 8 to 30 mm is used.

According to a seventh aspect of the present invention, there is provided a method for charging ironmaking dust into a smelting reduction furnace according to any one of the first to sixth aspects of the present invention, according to the degree of rise and fall of the bath temperature in the smelting reduction furnace. It is characterized in that the residence time of the charge in the gas atmosphere in the smelting reduction furnace is adjusted.

[0025] The method for charging iron-making dust into a smelting reduction furnace according to claim 8 is the method according to any one of claims 1 to 7, wherein the method includes the steps of: It is characterized by adjusting the residence time of the charge.

According to a ninth aspect of the present invention, there is provided a method for charging steelmaking dust into a smelting reduction furnace according to any one of the first to seventh aspects of the present invention, in accordance with information on a furnace wall heat load of the smelting reduction furnace. In addition to adjusting the residence time of the charge, the method is characterized in that the amount of the material to be charged into the smelting reduction furnace is adjusted in a manner of biasing the charging amount at a position in a horizontal cross section in the smelting reduction furnace. .

[0027] An apparatus for charging ironmaking dust into a smelting reduction furnace according to claim 10 is an apparatus for charging ironmaking dust into the smelting reduction furnace in a step of smelting ore in the smelting reduction furnace, After the iron-made dust containing water is retained in the high-temperature gas atmosphere in the smelting reduction furnace, the iron-made dust thus removed from the smelting reduction furnace is placed at a position in the bath surface of the smelting reduction furnace. When charging for
It is characterized by having a mechanism for adjusting the charging distribution.

An apparatus for charging ironmaking dust into a smelting reduction furnace according to claim 11 is an apparatus for charging ironmaking dust into the smelting reduction furnace in a step of smelting ore in the smelting reduction furnace, In the high-temperature gas atmosphere in the smelting reduction furnace generated from the smelting reduction furnace, iron-made dust containing water,
Ore, carbonaceous material, waste synthetic resin material, and slag-making material are preliminarily mixed with one or more kinds thereof, and the mixture is retained in the high-temperature gas atmosphere. When charging to the position in the bath surface in the smelting reduction furnace, a mechanism for adjusting the charging distribution is provided.

According to a twelfth aspect of the present invention, there is provided an apparatus for charging ironmaking dust into a smelting reduction furnace, wherein the ironmaking dust containing water, ore, carbonaceous material, waste synthetic resin material, and slag-making are contained in the step of refining ore in the smelting reduction furnace. A mechanism for feeding the mixed material containing the material into the smelting reduction furnace, and a position higher than a bath surface formed in the smelting reduction furnace; Contact with the hot gas generated from the furnace,
Further, a location where the mixed substance is retained is provided at a position where the mixed substance can be heated by the high-temperature gas.

According to a thirteenth aspect of the present invention, in the smelting reduction furnace, the apparatus for charging ironmaking dust according to the twelfth aspect is characterized in that the mixed substance is mixed with the molten material in accordance with the degree of rise and fall of the bath temperature in the smelting reduction furnace. The present invention is characterized in that a mechanism is provided for mechanically pushing the mixture into a bath in the smelting reduction furnace while adjusting the residence time in a high-temperature gas atmosphere.

[0031]

DESCRIPTION OF THE PREFERRED EMBODIMENTS As described above, the present invention has developed a method of utilizing ironmaking dust as an iron source, a carbon material source, and a raw material of a slag-making material component, and applies the method to a smelting reduction ironmaking process. The true value is exhibited by doing so. Next, an embodiment of the present invention will be described.

(1) First, an embodiment will be described with reference to the drawings. FIG. 1 is a schematic vertical sectional view of a smelting reduction furnace illustrating an embodiment of a method and an apparatus of the present invention. Reference numeral 61 denotes a smelting reduction furnace main body, for example, an iron bath type smelting reduction furnace. 62 is a furnace wall, 63 is a furnace tub, and 6
Reference numeral 4 denotes a place where the charge is temporarily retained in the furnace atmosphere, that is, a retention place. As shown in the figure, the stagnation place 64 is provided at the lower part of the furnace wall 62, and its surface is inclined toward the inside of the furnace. Further, a pusher 65 and a scraping device 66 that stroke along the inclined surface are provided. In the upper part of the furnace main body 61, a charging chute 67 for charging and a lance 68 for blowing oxygen are provided.

Iron-made dust containing water, or one selected from ores, carbonaceous materials, waste synthetic resin materials and slag-making materials
A raw material and / or fuel (collectively referred to as “charge”) 69 composed of a mixture with the seeds or more is charged from the charging chute 67 to the retaining area 64. Charge 6 put in staying place 64
9 is heated by the high-temperature gas generated by the smelting reduction furnace,
Cause various reactions. The gas generated from the smelting reduction furnace is generated by a reaction between the oxygen-containing gas 70 blown from the lance 68 and a substance in the furnace (all of solid, liquid, and gas). Next, the charge 69 which has undergone dehydration, devolatilization or metallization change at the retention place 64 is pushed by a pusher 65 in an appropriate amount in a timely manner, and is charged into a slag / metal bath 71 serving as a bath part in the furnace tub 63. Then, a part of the gas is converted into a furnace gas as a product gas.

A bottom blow gas nozzle 73 is provided at the bottom of the furnace, and a stirring gas 74 is blown into the slag metal bath 71 to promote a smelting reaction. Further, a side lance 75 is provided on the furnace wall, and an oxygen-containing gas 70 is blown into the furnace to promote smelting.

Here, the ironmaking dust containing water includes dust for removing high-temperature gas generated in the smelting reduction furnace,
In addition to dust in waste gas generated in the ore pre-reduction furnace,
Dust generated from electric furnaces at steelworks, dust generated from converters, dust collected from electric furnace buildings and converter buildings,
It is possible to use steelmaking dust containing a wide variety of components such as waste gas dust from steel heating furnaces, dust generated in a sintering machine, iron oxide, fixed carbon, and slag-forming components such as CaO and SiO _2. .

The above-mentioned smelting equipment is provided with various measuring instruments usually required for performing the smelting reduction smelting operation, and by appropriately attaching the following equipment, the smelting operation can be more easily controlled. It is desirable to stabilize operations and to maintain equipment. Device for adjusting the residence time of the charge. A slurrying device for charging the charge in a slurry state into the furnace. In order to control the length of time required for the charge to reach the holding place from the charging chute for a long time, with the aim of strengthening the shape of the slurry-like charge, a reinforcing substance is added to enhance the shape retention of the slurry, Alternatively, a shape-enhancing device for coating a slurry-like charge with a shape-enhanced thin plate-like material to form a rod or plate. However, a fibrous substance, a mesh-like substance, a tacky / adhesive substance is suitable as a shape reinforcing substance, and as a material, an iron wire (tessa, wire mesh, etc.), carbon fiber, a normal binder, various binders, or Materials that solidify or fibrillate upon contact with high-temperature gas are suitable. The effect of adding the shape-enhancing substance is that the greater the amount of water, steam, or volatile matter generated from the charge, such as adherent water, crystal water, or stored water, the more difficult it is to maintain the initial slurry shape. In consideration of the above, the one having an action of forming an appropriate gas vent hole is effective. In addition, it is in the form of a thin plate with vent holes from the contained slurry, which covers the entire periphery of the slurry over its entire length. Further, those which do not harm the bath components are desirable. The thickness is 0.1-1mm
The degree is suitable. A simple pretreatment device for sintering and granulating raw materials and fuels such as iron and steel dust, fine ore, coal powder, and slag material. A device that distributes the charge from the charging chute to the stagnant place with uneven distribution in the furnace wall inner circumferential direction. In this method, the charge is additionally distributed mainly in a place where the furnace wall heat load is large and the conditions are severe, thereby fulfilling the role of the cold material. The furnace wall has an internal water-cooled structure. This is to ensure heat resistance.

(2) Next, according to the present invention, the method and apparatus for charging the raw material and fuel containing iron-made dust containing water into the smelting reduction furnace according to the reasons or the limiting conditions for limiting the structure of the method and apparatus as described above. The operation and effect will be described.
Table 1 shows examples of component analysis results of iron-making dust, ore, and coal.

[0038]

[Table 1]

(A) A large amount of iron-made dust and water containing water
High-temperature gas generated in smelting reduction furnaces even for low-grade ores
If it is kept in the atmosphere for a certain period of time and brought into contact,
And the ore is heated or preheated and the attached moisture evaporates,
The crystal water in the ore decomposes and evaporates. The temperature rises further
The reduction of oxides, especially iron oxide, proceeds. Like this
Smelted iron dust or ore into the smelting reduction furnace bath
I do. Here, if the amount of water adhering to steelmaking dust is large, 3
It contains about 0 wt.%, So to evaporate this
Is t in the high temperature gas atmosphere._r= 5W / S (mi
n). Where t_r:Residence time
(Min), W: water content of iron-made dust containing water
(External number) (-), S: specific surface of iron-made dust containing water
Product ≡α / (dρ) (m^Two/ T), α: steel containing water
Dust shape factor (-), d: Iron-made dust containing water
Typical diameter (m), ρ: Bulk density of iron-made dust containing water
(T / m ^Three).

As described above, if the attached water and crystal water of the ironmaking dust, ore, coal, waste synthetic resin material, and slag-making material are evaporated in advance, the evaporation and decomposition of the moisture can be performed in the melting bath of the smelting reduction furnace. Does not occur, so that the unit consumption of coal and oxygen can be reduced accordingly. In addition, if the coal is devolatilized, the molten slag / metal bath does not lose the heat of decomposition accompanying the devolatilization of the coal, so that the unit consumption of coal and oxygen can be reduced accordingly. Further, if the reduction of the ore is advanced, the heat of ore decomposition deprived in the slag / metal melting bath can be reduced, so that the unit consumption of coal and oxygen can be reduced accordingly.

Here, the time at which the raw materials such as ironmaking raw materials and ores are brought into contact with the high-temperature gas is referred to as during the smelting, and the contact place is the space in the smelting reduction furnace, on the furnace wall, or at the flow of the high-temperature gas. Restricting to the inside of the piping system, which is a path, is to make it possible to contact the gas as hot as possible and to easily ore the charging ore into the bath without having to separately make equipment for contacting the two. It is. Hereinafter, the same reason applies to coal or slag-making material instead of ore.

(B) If a carbon material such as coal is brought into contact with a high-temperature gas atmosphere of 1000 ° C. or higher generated in a smelting reduction furnace while holding it for a predetermined time t _V , non-coking coal called general coal is obtained. The hydrogen content usually contained therein is reduced by the evaporation of attached water (enclosed water).
Volatile components of 0 wt.% Or more can be decomposed and evaporated and removed to approximately 1% or less. The predetermined contact time t _V with the gas is
Formula: t _V = 5W _c / S _c (where t _V : residence time (mi
n), W _c : volatile matter of carbon material (internal number) + stored moisture (outside number)
+ Attached moisture (external number) (wt.%), S _c : specific surface area of carbon material, S _c ≡α / (d _c ρ _c ) (m ² / t), α: shape factor of carbon material (-), D _c : representative diameter of carbon material (m),
ρ _c : represented by the bulk density (t / m ³ ) of the carbon material. The decomposition / evaporation time t _V ′ of volatile matter in coal is calculated by the following equation:
t _V ′ = d _c VM / S _c (where VM: volatile matter (wt.%) of coal). Here, the inside of the flow path leading to the outside of the smelting process is, for example, a hood duct or the like provided from the bath of the smelting reduction furnace.

Conventionally, the heat load on the furnace wall due to the furnace wall heat load, that is, the heat load on the furnace wall due to the sensible heat and latent heat of the gas produced by the smelting reduction furnace is limited to suppress the heat loss. For this reason, the secondary combustion rate of the smelting reduction furnace has been conventionally set at 30% to at most over 40%. On the other hand, by applying the method of the present invention, it is possible to obtain an effect that the secondary combustion rate can be increased from 40% to about 80% without significantly increasing the heat loss. In this case, the iron oxide contained in the iron-making dust is also reduced by the following formula: Fe _X O + CO = xFe + (1/2) CO ₂ Fe _X if there is an atmospheric CO gas and a carbon component in direct contact with the atmosphere. _{O + H 2 = xFe + (} 1/2) proceeds by _{H 2 O Fe X O + C} = xFe + CO. And, it further contributes to reduction of the unit consumption of coal and the unit consumption of oxygen, and the reduction of equipment cost.

(C) In addition, water-containing iron-made dust is
When the ore and the carbonaceous material are mixed and retained in a high-temperature gas atmosphere generated by a smelting reduction furnace of at least 1000 ° C. or more, desirably 1200 ° C. or more, and the retention time _tr is secured by the formula (1 ′) or more, the above (b) The effect of item (1) is further improved.

_Tr = 5 W / S (1 ') where _tr : residence time (min) W: water content of the mixture (wt.%) S : Specific surface area of the mixture {α _i / (d _i ρ _i )} x _i
(M ² / t) where, i: mixture subscript symbols x _i representing the respective constituents: weight ratio of the mixture the constituent material (-) alpha _i: shape factor in the mixture the constituent material (-) d _i: mixture constituent Representative diameter of substance (m) ρ _i : Bulk density (t / m ³ ) of each constituent substance of the mixture. That is, the ore inevitably produces metallic iron, and a metal having a metallization ratio of at least 40% or more, usually about 50 to 80% can be easily obtained. Here, the ratio of coal mixed with the ore is made larger than the amount required for metallization of the ore, and is adjusted to an amount commensurate with the amount of carbon material required in the bath section of the smelting reduction furnace. Effect of secondary combustion increase by volatilization and D
The ore reduction rate is much higher than the ore reduction rate in the fluidized bed, which is a preliminary reduction furnace in the IOS method. In this way, the unit consumption of coal and the unit consumption of oxygen are reduced, and the unit consumption of coal, which is the level in the process of charging into a smelting reduction furnace or a preliminary reduction furnace without drying of high-moisture-content dust, ore, and coal, is achieved. : 800 to 1200 kg / t, oxygen intensity: 60
Reduced to 1 / 2-1 / 3 of 0~900Nm ³ / t.

(D) If a slurry of the charge material is charged from a charging chute, the raw material and the material to the smelting reduction furnace can be obtained.
Not only the fuel is easily transported, but also the control of the charging speed to the smelting reduction furnace is facilitated, and the required residence time in the smelting reduction furnace can be easily secured and controlled.

(E) On the other hand, in a system in which a charge such as a raw material and a fuel is temporarily retained in a retaining location and is kept in contact with a high-temperature gas, there is a limit in suppressing the furnace wall heat load due to the combustion heat of the fuel. Therefore, in a state where the charge is hung from the upper part of the furnace and suspended, that is, in a state where the string-like charge is suspended, the efficient contact with the high-temperature gas and the required residence time in the high-temperature gas are ensured. It is possible to do. Furthermore, the shape reinforcement of the suspended charge is enhanced, and after maintaining the required time, the slag
If inserted in a metal bath, the furnace wall heat load can be further reduced,
It can be used for furnace wall protection. Here, as the shape-enhancing substance or the shape-enhancing thin plate-like material, those described in the above item (1) are used.

(F) The representative diameter of each charged substance is 8 mm
By using the above, even if so-called sinter feed ore or fine-grained coal of several mm is used as it is, the bonding strength can be sufficiently secured, while the short diameter is 30 mm.
If the following are used, the method can be carried out without delay in terms of thermal efficiency and reaction efficiency. For the minor axis,
It is more desirable that the thickness be 12 to 20 mm.

(G) If the residence time of the charge can be adjusted in accordance with the degree of rise and fall of the temperature of the bath in the smelting reduction furnace, it is possible to stabilize the reaction efficiency to a higher degree and to melt the raw material and fuel by excessive input. Operational instability of the reduction furnace can be suppressed.
The temperature of the smelting reduction furnace can be known directly or indirectly from the direct measurement of the product temperature using a thermocouple or the like, and the change in gas temperature and furnace wall heat load.

(H) A mechanism capable of adjusting the distribution of the charged material with respect to the position in the bath surface when charging the charged material into the bath section in the smelting reduction furnace is provided. The charge is distributed with respect to the bath surface in a distribution according to the above. For example, if it is put in the vicinity of the furnace wall, it can be used to reduce the heat load of the furnace wall over the part and to protect the furnace wall. In this case, reduce the proportion of carbon material in the charge,
Conversely, the heat load of the furnace wall in the part thereof is not increased by the burning of the carbonaceous material.

(I) In the case where the surface of the staying place is an inclined surface which is smaller than the angle of repose of the charge, the required staying time can be easily obtained for the charge deposited there. Of course,
The retention time can be ensured even when the surface of the staying place is made to have a repose angle or more and the moisture content in the input is increased so that the input adheres to the furnace wall.

(J) In order to prevent the charged material charged into the staying place from being excessively deposited, a device having a function of forcibly mechanically scraping and pushing the deposited charged material is provided.
As such, a pusher or mechanical scraping device is sufficient.

[0053]

Next, the present invention will be described in more detail with reference to examples. The tests were performed in Examples 1 to 3 within the scope of the present invention.
5 and Comparative Examples 1 and 2 outside the scope of the invention. In addition, the components of iron-making dust, ore, and coal of the used charge are in accordance with those shown in Table 1. Example 1
The main operating conditions and operating results of each test of 3, Examples 4 and 5, and Comparative Examples 1 and 2 are shown in Tables 2, 3 and 4, respectively.

[0054]

[Table 2]

[0055]

[Table 3]

[0056]

[Table 4]

Example 1 A smelting reduction furnace shown in FIG. 1 and a process flow shown in FIG. 2 were tested. The main test conditions are as follows. The ore was charged into the smelting reduction furnace 1 without preliminarily reducing it after the ore adhering to the ore was dried and removed by the ore drying equipment 3. The charcoal material was obtained by drying and removing adhering moisture from the raw coal material 21 in the coal drying facility 4. The slag forming material was a raw slag material 25 made of limestone and raw dolomite.
Each of the materials fired in the above was charged into the bath portion of the smelting reduction furnace 1 from the charging chute 67. On the other hand, steelmaking dust was used as a part of the raw material. As the ironmaking dust used, a collected dust 38 obtained when dust generated from the smelting reduction furnace generated gas 31 was removed was used. The collected dust 38 is obtained by crushing a semi-solid material collected by a dust remover 51 and subjected to a filter press treatment to an average particle size of about 20 mm. Moisture content is 2
0 wt.%, And the input unit consumption was increased to 250 kg / t. The collected dust 38 is supplied from the charging chute 67 to the smelting reduction furnace 1.
It was put into a retaining place (indicated by reference numeral 64 in FIG. 1) and was retained there for 5 minutes to evaporate adhering moisture. Since the furnace is constructed so that the surface inclination angle of the staying place 64 is equal to or less than the angle of repose, the dust does not slide down into the bath (reference numeral 71 in FIG. 1) depending on its own weight. The plane inclination angle was 30 °. However, the slag metal bath level lowered by tapping and slag rises due to charging of ore, coal and slag material into the bath 71,
The height of the bath surface is equal to or higher than the height of the dust that has accumulated and dried in the holding place 64, and the bath 71 swallows the dry dust in order, and the dust is charged into the bath 71 in such a form. The conditions were adjusted. In addition, it turned out that the angle of repose of the surface inclination angle of the above-mentioned staying place 64 depends on the charging speed of dust and operating conditions, and is approximately in the range of 20 to 40 °. In addition, the stirring gas (nitrogen) blown from the bottom of the smelting reduction furnace 1 was not usually blown during smelting.

As described above, in this embodiment, the equipment for drying the recovered dust 38 and the ore pre-reduction furnace 2 are omitted.
In addition, the use of the recovered dust 38 as ironmaking dust and the rationalization without blowing the stirring gas 74 were performed. Table 2 shows the operating conditions and results. Operations have been implemented to reduce manufacturing costs.

Example 2 Tests were performed using the smelting reduction furnace shown in FIG. 3 and the process flow shown in FIG. The main test conditions are as follows. That is, the dry ore 12 was charged into the fluidized bed type pre-reduction furnace 2, and the high-temperature ore treated to a reduction rate of 25% was charged into the smelting reduction furnace 1 inner bath 71. As in Example 1, the slag-making material and the carbon material were respectively baked and dried, and were charged into the bath 71 of the smelting reduction furnace 1.

Iron-making dust was used as a part of the raw materials.
As the ironmaking dust, the dust collected from the smelting reduction furnace 1
8 in a slurry form having a water content of 20 wt.
From 7, it was thrown into a holding place 64 in the smelting reduction furnace 1, and was kept there for 5 minutes to evaporate adhering moisture. Detention place 64
Make the furnace slightly larger than the angle of repose. The slurry dust 39 ′ is supplied in a continuous form to the holding place 64, and is charged into the bath 71 so that the trailing dust slides down on the inclined surface while pushing the leading dust. The plane inclination angle was 60 °. However, dry dust sometimes stays in place 6
4, it was forcibly charged into the bath 71 by the pusher 65 and the scraping device 66.

It has been found that the angle of repose of the surface inclination angle of the staying place 64 with respect to the slurry dust 39 ′ is widely distributed within the range of 40 to 80 ° depending on the charging rate and the operating conditions.

In this embodiment, since ironmaking dust was made into a water slurry and charged into the smelting reduction furnace with the slurry, it was easy to control the charging rate of the dust, and the water evaporation in the slurry in the smelting reduction furnace was easy. It is easy to adjust the amount. Since the collected dust 38 was slurried, the efficiency of conveying the collected dust to the smelting reduction furnace 1 was also improved. In addition, dust drying equipment can be eliminated, and the productivity of hot metal has been improved. If this method is applied, not only smelting reduction furnace generated dust,
Mill scale, electric furnace or converter dust, blast furnace dust, and other dust generated in steel works can be treated without substantially reducing the productivity of the present smelting reduction furnace. Table 2 shows the operating conditions and results. Operations have been implemented to reduce manufacturing costs.

Example 3 Tests were performed using the smelting reduction furnace shown in FIG. 5 and the smelting reduction steelmaking flow equipment shown in FIG.

The main test conditions were as follows. For the ore, the dry ore 12 was charged into the fluidized bed type pre-reduction furnace 2 and the reduction rate was 25%.
% Was charged into the bath 71 of the smelting reduction furnace 1. The fired slag-making material and the dried carbon material were charged into the bath 71 of the smelting reduction furnace 1. On the other hand, steelmaking dust was used as a part of the raw material. As ironmaking dust, recovered dust 38 from the smelting reduction furnace 1 was supplied into the smelting reduction furnace 1 in the form of a slurry having a water content of 30 wt. As a method for retaining the slurry dust 39 in the high-temperature gas atmosphere in the furnace, a charging chute 67 is used.
The dust suspended in a string form from the lower end of the string, that is, the string-like slurry dust 41, is slowly lowered so as to stay in the space atmosphere for 3 minutes, and the
1 was charged. At this time, a predetermined shape-enhancing substance was mixed into the slurry so that the slurry dust 39 could withstand such a suspended state. Table 5 shows the types of the shape reinforcing substances used and the compounding ratio thereof. Regarding the compounding ratio of the shape-enhancing substance, the test purpose was achieved in any case shown in Table 5.

In order to supply the slurry dust 39 in a string form, a slurry dust loading nozzle 4 having a nozzle hole 42 shown in FIG.
3 was attached. The nozzle diameter was 15 to 30 mm, and the lance nozzle 43 was a water-cooled structure. When the inner diameter of the furnace is large, the oxygen supplied to the smelting furnace into the furnace cannot be sufficiently covered by the acid supply from only one of the main lances 68 when the furnace inner diameter is large. Here, the side lance 7 is used as an auxiliary lance.
5 was smelted.

Table 2 shows the operating conditions and results. In this example, iron-made dust was converted into a water slurry, which was strengthened and suspended in a large number of strings from a charging chute and charged. Therefore, the charging rate was adjusted and the water content in the slurry in the smelting reduction furnace was adjusted. The adjustment of the amount of evaporation became easier. Further, the dust drying equipment can be eliminated, and the productivity of the hot metal can be improved. Since the collected dust 38 was slurried, the efficiency of conveying the collected dust to the smelting reduction furnace 1 was also improved.

[0067]

[Table 5]

Example 4 A smelting reduction furnace shown in FIG. 7 and a process flow shown in FIG. 4 were tested. The main test conditions are similar to Examples 2 and 3, except for the major differences:
In the fourth embodiment, as a method of supplying the slurry dust 39 into the furnace, as shown in FIG. 7, a plurality of supply pipes 78 for the slurry dust 39 are provided through the water-cooled structure furnace wall 79. The slurry dust extruded from the pipe 78 stays as the entangled string dust 44 in the staying place 64 and the space above it, and is charged into the bath 71 after the moisture is evaporated and dried. The residence time is 10 minutes. The slurry dust 39 was appropriately mixed with a shape-enhancing substance. The purpose of charging the slurry dust in this way is to increase the unit consumption of the slurry dust. The basic unit for charging dust was 460 kg / t in terms of a moisture-dry state, and 460 kg / t of carbonaceous material was mixed. Therefore, reduction of iron oxide in dust also progressed.

FIG. 8 shows the slurry dust loading nozzle 81 and its nozzle hole 8 as viewed from the furnace inner wall side of the water cooling furnace wall 79.
0 indicates the arrangement. The nozzle hole diameter was 15 to 30 mm. The intended purpose was achieved within the range of the pore diameter.

Table 3 shows the operating conditions and results. According to this embodiment, in addition to the effects obtained in Embodiments 2 and 3 (elimination of dust drying equipment, improvement in the controllability of the speed of charging the dust, and improvement in the workability of conveying collected dust), Production volume improved. In addition, the cooling effect of the water-cooled furnace wall was obtained.

Example 5 As a smelting reduction furnace, an auxiliary heating burner was provided on the furnace wall of the furnace shown in FIG. 5, and a test was performed according to the process flow shown in FIG. In the test, hot metal 50
A smelting reduction operation of 0 t / d was performed. In Example 5, as a condition for charging the charge to the smelting reduction furnace, carbon fiber was added to a water slurry obtained by adding iron-making dust to ore and coal to enhance the shape retention of the slurry, and the slurry hanged like a string. The charge was heated to dry. In addition, the furnace wall is protected by reducing the furnace wall heat load due to the burning of coal and other coal materials near the furnace wall, and the slurry moisture is reduced by controlling the charging speed of the charge into the bath. Evaporation was promoted. At this time, the ore and the coal used had a short diameter of 8 to 30 mm, and the diameter of the cord-like charge at the time of charging after slurrying was about 80 mm. The slag-making material was not fired and was charged into the bath as raw slag-making material.

When the test operation was continued, the following tests were performed. The residence time of the charge was adjusted according to the rise and fall of the bath temperature. The residence time of the charge was adjusted according to the information on the furnace wall heat load. The residence time of the charge was adjusted according to the information on the furnace wall heat load. (B) The distribution of the amount of material charged in the furnace in the horizontal section in the smelting reduction furnace was adjusted. Table 3 shows other detailed test conditions and results.

With respect to the change in the furnace wall heat load during the test operation, the residence time of the slurry charge and the charge rate were adjusted. Examples of each adjustment are shown in FIGS. FIG. 9 shows a change with time of the action for changing the residence time of the slurry-like charge with respect to the change in the furnace wall heat load of the smelting reduction furnace during operation. With tapping slag,
As the slag level in the furnace decreased, the furnace wall heat load fluctuated,
It has risen. Therefore, an action was taken to reduce the furnace wall heat load by shortening the charge residence time in the furnace. Thereafter, the tendency of reducing the furnace wall heat load appeared. Since there was concern that slag might adhere to the furnace wall, the charge retention time was slightly lengthened, and the heat load was adjusted to be stable at a predetermined value.

FIG. 10 shows the time course of the action in which the distribution of the slurry-like charge is adjusted at the position in the horizontal section in the smelting reduction furnace with respect to the change in the furnace wall heat load during operation. Indicates a change. In the figure, the slurry-like charge input chute is located at a position in the reactor horizontal plane as shown in FIG.
A, B, C and D are provided at four places. And it is the example which adjusted the charging amount distribution of the slurry-like charge for every location with respect to the time-dependent change of the furnace wall heat load of each location of A, B, C, and D. In the direction of the charging chutes A and D, the heat load on the furnace wall is low and stable due to the adhesion of slag to the furnace inner wall surface. On the other hand, in the directions B and C, the slag level in the furnace was reduced due to tapping slag, so that the furnace wall heat load fluctuated.
It has risen. Therefore, the amount of charging on the furnace wall side of the points B and C was increased, and an action of reducing the furnace wall heat load was taken. As a result, the furnace wall heat loads in the B and C directions were also stabilized. After that, the furnace wall heat load fluctuated and increased during the tapping slag timing as in the previous case. Then, the heat load was stabilized by the same action as last time.

[Comparative Example 1] Tests were performed using the smelting reduction furnace shown in FIG. 12 and the smelting reduction steelmaking flow equipment shown in FIG.

The main test condition is that the collected dust 38 having a water content of about 20 wt.% Collected by the dust remover 51 is dried by the dust drying device 82. And the obtained dry dust 3
8 ′ is inserted into the bath 71 from the charging chute 67. Further, the ore is dried by drying the raw ore 11 in the ore drying equipment 3 and further preheating in the ore preheating furnace 2p.
, And then charged into the bath section of the smelting reduction furnace 1. In addition, about charging of a carbonaceous material and a slag-making material, similarly to Examples 2-5, dry coal, calcined lime, and calcined dolomite were charged into the bath 71 of the smelting reduction furnace 1. Table 4 shows the operating conditions and results.

In this example, a dust drying apparatus was required, and much energy was required for drying the dust. [Comparative Example 2] A test was performed using the smelting reduction furnace shown in FIG. 12 and the process flow shown in FIG. The main test conditions are as follows. The ore is obtained by drying the raw ore 11 in the ore drying equipment 3, and then preliminarily reducing it in the fluidized bed type prereduction furnace 2, and then charging the ore into the inner bath of the smelting reduction furnace 1. On the other hand, the collected dust 38 having a water content of about 30 wt.% Collected by the dust remover 51 is charged into the bath 71 from the charging chute 67 of the smelting reduction furnace 1 without drying. In addition, as for the charging of the carbonaceous material and the slag-making material, the dry coal, the calcined lime and the calcined dolomite are mixed in the bath 71 of the smelting reduction furnace 1.
Was charged.

Table 4 shows the operating conditions and results. In this example, a dust drying device is not required, but a large amount of coal and oxygen were used to secure the bath temperature because dust containing moisture was charged into the bath of the smelting reduction furnace.

As an embodiment of the present invention, as described above,
Although the example based on the smelting reduction of iron ore has been described, the present invention is similarly effective in the case of smelting reduction of metal oxides such as Ni, Cr, and Mn.

[0080]

As described above, according to the present invention,
In the process of smelting and reducing iron ore to produce hot metal, the carbon material is secondarily burned with an oxygen-containing gas, and the heat is used to continuously smelt and reduce the oxide ore. It is possible to provide a method and an apparatus for charging steelmaking dust into a smelting reduction furnace to reduce the generation amount and provide an apparatus with a low equipment cost, which brings industrially useful effects.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view for explaining a main part of a smelting reduction furnace used in Example 1.

FIG. 2 is a process flow of Example 1 and Comparative Example 2.

FIG. 3 is a schematic longitudinal sectional view illustrating a main part of a smelting reduction furnace used in Example 2.

FIG. 4 is a process flow of Examples 2, 3, 4 and 5.

FIG. 5 is a schematic longitudinal sectional view for explaining a main part of a smelting reduction furnace used in Example 3.

FIG. 6 is a diagram showing a nozzle arrangement at the tip of a lance nozzle for extruding slurry dust from a charging chute of a smelting reduction furnace.

FIG. 7 is a schematic longitudinal sectional view for explaining a main part of a smelting reduction furnace used in Example 4.

FIG. 8 is a view showing a nozzle arrangement of a slurry dust charging hole in a water cooling structure furnace wall for pushing out slurry dust from a furnace wall of the smelting reduction furnace.

FIG. 9 is a graph showing adjustment results of a charging speed and a charging position distribution of a charged object with respect to a change in bath temperature in Example 5.

FIG. 10 is a graph showing adjustment results of a charging speed and a charging position distribution of a charged object with respect to a furnace heat load variation in Example 5.

FIG. 11 is a schematic plan view of a smelting reduction furnace illustrating a position of a charging chute of a charge during a heat load test for each furnace wall position in Example 5.

FIG. 12 is a schematic longitudinal sectional view for explaining a main part of a smelting reduction furnace used in Comparative Examples 1 and 2.

FIG. 13 is a process flow of Comparative Example 1.

FIG. 14 is a main part of a process flow of a pilot plant of the smelting reduction iron making method according to Prior Art 1.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Smelting reduction furnace 2p Ore preheating furnace 2 Preliminary reduction furnace 3 Ore drying equipment 4 Coal drying equipment 5 Coal devolatilization furnace 6 Slag making material firing furnace 11 Raw ore 12 Dry ore 13 Preliminary reduced ore 14 Char-containing preliminary reduced ore 20 High calorie Fuel 21 Raw coal material 21 'Coal 22 Dry coal 25 Raw slag material (limestone, raw dolomite) 26 Burnt slag material (calcined lime, lightly burned dolomite) 31 Gas generated in the smelting reduction furnace 32 Gas generated in the preliminary reduction furnace 33 Preheating furnace Generated gas 34 Collected gas 35 Collected steam 36 Hot metal 37 Slag 38 Collected dust 38 ′ Dry dust 39 Slurry dust 39 ′ Dry dust 40 Slurry equipment 41 String-like slurry dust 42 Nozzle hole 43 Lance nozzle 44 Entangled string dust 45 Furnace inner wall nozzle 46 Oxygen 47 Air 48 Nitrogen 49 Gas calorie adjusting fuel 50 Heat REFERENCE SIGNS LIST 51 dust remover 52 gas holder 53 booster 54 power generation equipment 56 steam recovery boiler 57 gas air emission 58 heat exchanger 59 slurrying device 60 shape reinforcement device 61 smelting reduction furnace main body 62 furnace wall 63 furnace bath tub 64 staying place 65 pusher 66 scraping Removal device 67 Input chute 68 Lance 69 Charge 70 Oxygen-containing gas 71 Slag metal bath (bath part) 72 Charge deposit layer 73 Bottom blow gas nozzle 74 Stirring gas 75 Side lance 76 Iron ore 76 'Preheat ore 76 "Reserve Reduction ore 77 Preheating furnace 78 Slurry dust supply pipe 79 Water cooling structure furnace wall 80 Nozzle hole 81 Slurry dust loading port 82 Dust drying device

Continuing from the front page (72) Inventor Masahiro Kawakami 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Terutoshi Sawada 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Stock In-house (72) Inventor Takeshi Sekiguchi 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Pipe Co., Ltd. (72) Inventor Masayuki Watanabe 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Japan Pipe Co., Ltd. F term (reference) 4K012 CB02 CB03 CB04 CB05

Claims (13)

[Claims] 1. A mixture containing iron-containing dust containing water in a step of smelting ore in a smelting reduction furnace and at least one selected from ores, carbonaceous materials, waste synthetic resin materials and slag-making materials. Wherein the charge is formed into a slurry state in advance, and the slurry is mixed with a shape-enhancing material for holding and strengthening the shape of the slurry. Or, the slurry is coated with a shape-enhanced sheet-like material to form a rod or plate, and the thus obtained charge slurry is subjected to smelting in the smelting reduction furnace,
A method for charging iron-making dust into a smelting reduction furnace, which comprises charging a high-temperature gas generated from the smelting reduction furnace into a bath section of the smelting reduction furnace while exposing the gas to the atmosphere in the smelting reduction furnace. 2. A method for charging iron ore dust into the smelting reduction furnace in the step of smelting ore in the smelting reduction furnace, wherein high temperature generated from the smelting reduction furnace during smelting in the smelting reduction furnace. In the atmosphere of the gas in the smelting reduction furnace, the iron-made dust containing water is mixed with the following formula (1): _tr = 5W / S ---------------- (1) _tr : residence time (min) W: water content (external number) of iron-made dust (wt.%) S: specific surface area of iron-made dust containing water ≡α / (d)
ρ) (m ² / t) α: Shape factor of iron dust containing water (−) d: Representative diameter of iron dust containing water (m) ρ: Bulk density of iron dust containing water (t / after a residence time t _r or represented by m ^3), thus characterized by charging the iron dust that is remove water to the bath portion of the smelting reduction furnace, instrumentation and steel dust to the smelting reduction furnace How to enter. 3. A method for charging iron ore dust into the smelting reduction furnace in a step of smelting ore in the smelting reduction furnace, the method comprising: In the atmosphere of the gas in the smelting reduction furnace, water-containing iron-making dust and at least one selected from ores, carbonaceous materials, waste synthetic resin materials, and slag-making materials are mixed in advance, and this mixture is Formula (1 ′): _tr = 5 W / S (1 ′) where _tr : residence time (min) W: water content of the mixture (wt. %) S: Specific surface area of the mixture {α _i / (d _i ρ _i )} x _i
(M ² / t) where, i: mixture subscript symbols x _i representing the respective constituents: weight ratio of the mixture the constituent material (-) alpha _i: shape factor in the mixture the constituent material (-) d _i: mixture constituent The representative diameter (m) of the substance ρ _i : After the mixture has been retained for a time _tr or more represented by the bulk density (t / m ³ ) of each constituent substance of the mixture, the mixture from which water has been removed in this way is subjected to bathing in the smelting reduction furnace. A method for charging steelmaking dust into a smelting reduction furnace, which comprises charging into a smelting reduction furnace. 4. The method according to claim 2, wherein the material to be charged into the smelting reduction furnace is charged in a slurry state and charged into the smelting reduction furnace. . Here, the representative diameter d of the iron-made dust containing water or the representative diameter of each constituent material of the mixture represents the representative diameter in the slurry state. 5. The charge according to claim 4, wherein the charge in the slurry state is mixed with a shape-enhancing substance for maintaining the slurry in a required shape, or the charge in the slurry state. Is coated with a sheet material having a shape-enhanced shape to form a bar or a plate, and thus the slurry is formed. 6. A method according to claim 1, wherein the substance to be charged into the smelting reduction furnace has a representative diameter of each substance within a range of 8 to 30 mm. A method of charging ironmaking dust into a smelting reduction furnace. 7. The smelting reduction furnace according to any one of claims 1 to 6, wherein the charge in the gas atmosphere in the smelting reduction furnace is changed according to a rise / fall of a bath temperature in the smelting reduction furnace. A method for charging steelmaking dust into a smelting reduction furnace, comprising adjusting the residence time. 8. The melting method according to any one of claims 1 to 7, wherein the residence time of the charge is adjusted according to the information on the furnace wall heat load of the smelting reduction furnace. A method of charging steelmaking dust into a reduction furnace. 9. The smelting reduction furnace according to any one of claims 1 to 7, wherein the residence time of the charge is adjusted according to information on a furnace wall heat load of the smelting reduction furnace. A method for charging steelmaking dust into a smelting reduction furnace, comprising adjusting a biasing method of a charging amount of a substance to be charged into the smelting reduction furnace at a position in a horizontal cross section in the smelting reduction furnace. 10. An apparatus for charging iron smelting dust into the smelting reduction furnace in the step of smelting ore in the smelting reduction furnace, wherein a high-temperature gas atmosphere in the smelting reduction furnace generated from the smelting reduction furnace is provided. In, after the iron-made dust containing water is retained, when charging the iron-made dust thus removed with water to the bath surface position in the smelting reduction furnace,
An apparatus for charging steelmaking dust into a smelting reduction furnace, comprising a mechanism for adjusting the charging distribution. 11. An apparatus for charging iron smelting dust into the smelting reduction furnace in the step of smelting ore in the smelting reduction furnace, wherein the smelting reduction furnace generates a high-temperature gas atmosphere in the smelting reduction furnace. Inside, iron dust containing moisture,
Ore, carbonaceous material, waste synthetic resin material, and slag-making material are preliminarily mixed with one or more kinds thereof, and the mixture is retained in the high-temperature gas atmosphere. A mechanism for adjusting the charging distribution when charging the smelting furnace to a position in the bath surface of the smelting reduction furnace, wherein the smelting reduction furnace is charged with ironmaking dust. 12. A mechanism for feeding a mixed substance containing iron-containing dust containing water, ore, carbonaceous material, waste synthetic resin material and slag-making material to the smelting reduction furnace in the step of smelting the ore in the smelting reduction furnace, It is a position higher than the bath surface formed in the smelting reduction furnace, and the mixed substance charged by the charging mechanism is brought into contact with a high-temperature gas generated from the smelting reduction furnace,
An apparatus for charging steelmaking dust into a smelting reduction furnace, wherein a place where the mixed substance is retained is provided at a position where the mixed substance can be heated by the high-temperature gas. 13. The invention according to claim 12, wherein the mixture is mechanically adjusted while adjusting the residence time of the mixed substance in the high-temperature gas atmosphere according to the degree of rise and fall of the bath temperature in the smelting reduction furnace. An apparatus for charging steelmaking dust into a smelting reduction furnace, further comprising a mechanism for pushing the ironmaking dust into a bath in the smelting reduction furnace.