JPH0641606B2 - Apparatus and method for slag bath smelting reduction production of ferrous alloy melt - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a slag bath type smelting reduction production apparatus and method for molten iron-based alloy, that is, a raw material mainly containing iron oxide is melt-reduced to produce molten iron-based alloy. More specifically, the present invention relates to an apparatus and a method for producing hot metal, crude steel, molten ferrochrome, molten ferromanganese, etc., or melting scrap by slag bath smelting reduction.

[Conventional technology]

When iron is produced from iron ore as a raw material, the current mainstream is
The method of going through a blast furnace is adopted. However, in the method of passing through a blast furnace suitable for mass production, a step of coking coal and a step of agglomerating the powder ore are required, and the equipment becomes large and the construction cost becomes huge. Further, it is not easy to take a flexible operation form according to the production amount, and in such a case, there remains a problem that the operation adjustment of the furnace becomes extremely difficult. Therefore, a smelting reduction method that can adopt a more direct process as a method for producing a large amount of molten metal instead of the blast furnace method and that can be produced by a more downsized equipment has been studied for many years.

There are many types and formats of smelting reduction method, but recently,
Studies on the iron bath smelting reduction method have been actively conducted.
That is, it has been known for a long time that when iron ore is added into the furnace when producing molten steel from the hot metal in an oxygen converter, the iron ore is reduced by the carbon in the hot metal to produce iron. In recent years, for the purpose of expanding the thermal margin of the converter, a study has been made to add a carbonaceous material in the converter and increase the scrap mixing ratio by the heat generated by burning oxygen, and with this as a trigger,
BACKGROUND ART Research on an iron bath-type smelting reduction iron manufacturing method in which carbon material and iron ore or partially reduced ore are added to a converter to produce iron has been actively conducted.

By the way, the amount of heat generated when the carbonaceous material is burned to carbon monoxide is only one half or less of the amount of heat generated when carbon monoxide is further burned to carbon dioxide (hereinafter referred to as secondary combustion). Therefore, in the iron bath smelting reduction method, in order to reduce the carbonaceous material and the oxygen gas basic unit, the secondary combustion rate is improved and the heat generated during secondary combustion is transferred to the hot metal / slag bath, which is the site of the reduction reaction. It is an important issue to improve the efficiency of heat application (hereinafter referred to as heat application efficiency) at the same time.

However, when the amount of slag is normal in the converter, the molten metal is inevitably exposed to the atmosphere, and as a result, a chemical reaction of CO ₂ + Fe → CO + FeO or CO ₂ + C → 2CO occurs, which causes the secondary combustion rate. However, if the secondary combustion rate is forcedly increased in the upper space of the molten metal, there is a problem that the heat deposition efficiency decreases.

As an epoch-making means for solving this problem, a so-called carbonaceous material suspended mass slag / iron bath smelting reduction method was invented during the smelting reduction of ferrochrome. Japanese Patent Laid-Open No. 61-213310 discloses a method for producing a molten iron-based alloy.

The main points are: (1) By setting the amount of slag to 250 kg or more per ton of molten metal, preferably 300 to 480 kg, the molten iron alloy layer and the splash generated by bottom blowing directly contact the high temperature atmosphere. To improve the secondary combustion rate. (2) By keeping 20% or more of the slag weight carbon content in the slag, the foaming state of the slag is appropriately maintained to prevent sloping. (3) Set the bottom blown gas amount ratio to 3 to 30%, slag MgO
+ Al ₂ O ₃ is suppressed to 23% or less and its CaO / SiO ₂ is 0.8 to 1.9.
By keeping the above range and the total weight ratio of ore and carbonaceous material added from the top of the slag layer to 60% or more, the heat deposition efficiency is improved. As a result, it has become possible to significantly improve the secondary combustion rate compared to the conventional method while maintaining the heat transfer efficiency at about 90% or more. Although there are many differences in the technical idea, an example of causing a smelting reduction reaction in a foaming slag on an iron bath is also described in JP-A-58-144407.

[Problems to be Solved by the Invention]

However, as in the invention described in Japanese Patent Laid-Open No. 61-213310, when the hot metal and slag are strongly stirred to such an extent that the heat deposition efficiency can be kept high, the contact between the hot metal and the carbon dioxide gas atmosphere cannot be completely prevented. Therefore, a slight decrease in the secondary combustion rate cannot be avoided.

Further, since the refractory unit consumption of the furnace wall above the position where it contacts the slag is higher, even if an attempt is made to apply the water cooling structure of the furnace wall above the level of molten steel that is commonly used in electric furnaces, the bottom blown gas Due to significant fluctuations in molten metal level and bubbling due to stirring, it becomes impossible to cool the furnace wall near the boundary between the molten metal and slag, and eventually wear of this part shortens the life of the refractory material of the entire furnace. Moreover, when the hot water is intermittently tapped at intervals of 2 to 3 hours without continuous tapping, the molten metal generated during that time raises the level of the molten metal in the furnace. Therefore, if only the portion that does not come into contact with the molten metal has a water-cooled structure, the portion where the refractory is lined will come into contact with the slag over a considerable height. In addition, the refractory basic unit mentioned above becomes high means that the basicity of the slag must be lowered to about 1.2 to 1.4 in order to appropriately foam the slag, and the heat transfer efficiency is high but the secondary It is based on the fact that the exhaust gas temperature usually exceeds 1,700 ° C due to the high combustion rate.

Further, since the molten metal and the slag are strongly stirred, the molten metal is almost saturated with carbon due to the action of the carbonaceous material suspended in the slag. That is, a fixed carbonaceous material is required for carbon saturation, and particularly when using coal having a high volatile content as the carbonaceous material, the carbonaceous material unit becomes high.
On the other hand, since the carbonaceous material is suspended in the slag, the carbonaceous material flows out together with the slag when the slag is intermittently discharged without incinerating during continuous operation, and the carbonaceous material unit is deteriorated. Also, usually 3-10%
In order to reduce the iron oxide concentration in the slag, which is contained to some extent, and improve the iron yield, a finishing reduction period is required, and as a result, productivity is reduced. Such things include hot metal, ferromanganese molten metal by a large amount slag iron bath smelting reduction method,
This is a problem common to the production of ferrochrome molten metal and the melting of scraps, and even in the publicly known materials thereafter, no example is found in which the above-mentioned essential problems of the iron bath smelting reduction method have been solved.

The present invention has been made in view of the above problems, and an object thereof is to reduce the basic unit of refractory, further increase the secondary fuel rate and heat efficiency, while reducing the basic unit of coal and oxygen gas, It is an object of the present invention to provide an apparatus and a method for producing a slag bath-type smelting reduction of molten iron-based alloy capable of carbon-unsaturating a product.

[Means for Solving the Problems]

In the present invention, basically, the iron bath is eliminated, and the smelting reduction proceeding site is set to the molten foaming slag region in which the carbonaceous material is suspended. In other words, as long as there is a slag phase on the iron bath, if the slag is strongly stirred to achieve a high secondary combustion rate and high heat transfer efficiency, the secondary combustion rate will decrease and the furnace at the iron bath / slag boundary will Since it is unavoidable that wall water cooling becomes impossible, it was focused on that it can be solved by top-blown and bottom-blown only a single slag phase.

As shown in FIG. 1, a slag bath type smelting reduction manufacturing apparatus for molten iron-based alloys of the present invention has an airtight structure smelting reduction furnace body having a water cooling wall formed in a substantially rectangular cross section and extending in the longitudinal direction. 1 and a molten metal storage furnace body 2 arranged at one end thereof
It is applied to a smelting reduction manufacturing apparatus equipped with.

The characteristic is that the smelting reduction furnace body 1 has an exhaust gas port 7 at the ceiling part or the side upper part thereof, and is divided into a slag bath type smelting reduction part 1A and a deferred calming carbonaceous material separation slag part 1B. Is made. In the slag bath smelting reduction section 1A, since the iron-based oxide in the slag 4 is melted and reduced by the solid carbonaceous material suspended in the foaming slag bath, the ceiling portion 1e of the furnace body 1 is
Top blowing lance 5 for blowing oxygen gas or oxygen-containing gas
And a charging port 6 into which iron-based metal oxide, carbonaceous material, limestone, and the like are poured. The side wall of the furnace body 1 is provided with a horizontal blowhole 10 for blowing powdered metal oxide, powdered carbonaceous material, dust and the like, and the bottom portion 1b of the furnace body 1 is provided with oxygen gas, nitrogen gas to a slag bath. Alternatively, a bottom blower port 9 for blowing an inert gas or the like is provided, and the molten metal 11 generated by the smelting reduction is flowed to the bottom of the bottom blowing port 9, so that the molten metal 11 is inclined in the longitudinal direction toward the molten metal storage furnace body 2. A refractory gutter 12 is formed. Then, at the other end of the furnace body 1, in order to calm the bubbling slag, the slag bath-type smelting reduction section 1A
The slag 4 can be overflowed and the bottom part is separated by the partition wall 13 which communicates with the refractory gutter 12. On the side wall of the deferred calming carbonaceous material separation and slag portion 1B, a blowing tuyere 14 for laterally blowing carbonaceous material and carrier gas or oxygen gas and cooling gas, and a calming treatment provided below the blowing tuyere 14 Outlet 1 for discharging the generated slag
And 5 are provided. A refractory gutter 12 is provided in the molten metal storage furnace body 2.
The molten metal 11 flowing down from the pool is stored, and a tap hole 16 for taking out the stored molten metal 11 is provided.

It should be noted that the ceiling 1e of the smelting reduction furnace body 1 may be provided with a scrap addition port 17 into which iron-based scrap is introduced, in addition to the charging port 6 into which the iron-based metal oxide is poured.

As shown in FIG. 4, the bottom portion 18 a of the molten metal storage furnace body 18
In addition, a bottom blower port 19 for blowing oxygen gas into the iron bath may be formed, and a charging port 20 for supplying desulfurizing material such as limestone may be provided in the ceiling portion 18b.

In addition to the charging port 20 for supplying the desulfurizing material, a scrap adding port 21 for charging the iron-based scrap may be provided in the ceiling portion 18b of the molten metal storage furnace body 18.

As shown in FIG. 5, the smelting reduction furnace body 1 includes a refractory gutter 12
It is preferable to have a structure that can be divided into a lower furnace body 1D including the above, and an upper furnace body 1U in contact with the foaming slag bath and gas.

The molten metal storage furnace bodies 2 and 18 are also divided into lower furnace bodies 2D and 18D that are in contact with the iron bath 11 and upper furnace bodies 2U and 18U that are not in contact with the iron bath 11 as shown in FIGS. 1 and 4. It is good to have a structure that allows it.

On the other hand, the invention of the slag bath type smelting reduction manufacturing method for molten iron-based alloys has a closed smelting reduction furnace body 1 having a substantially rectangular cross section and extending in the longitudinal direction in FIGS. 1 and 4.
, Iron-based metal oxide, carbonaceous material, limestone, etc. are poured into the foaming slag bath generated in the slag bath type melting and reducing section of the furnace body 1, and oxygen gas or oxygen-containing gas is blown into it.
The molten metal 11 in which the iron-based metal oxide is melt-reduced and poured into the bubbling slag bath is stored in molten-metal storage furnace bodies 2 and 18 connected to one end of the melting-reduction furnace body 1, and the molten metal 11 is intermittently stored. The slag that has flowed over the partition wall 13 to form the deferred calming carbonaceous material separation slag portion 1B formed at the other end of the smelting reduction furnace body 1 is blown sideways. That is, the melt reduction is promoted by stirring with the carrier gas or the oxygen gas and the cooling gas, and then the slag that has been calmed is discharged.

Chromium oxide or manganese oxide may be poured into the smelting reduction furnace body 1 in addition to the iron-based metal oxide.

While pouring the iron-based metal oxide into the smelting reduction furnace body 1,
It is also possible to introduce iron-based scrap.

The desulfurization material may be supplied into the molten metal storage furnace body 18 and oxygen gas may be blown into the iron bath.

While supplying the desulfurizing material into the molten metal storage furnace body 18, iron-based scrap can also be charged.

〔The invention's effect〕

In the slag bath type smelting reduction production apparatus and method for molten iron-based alloy of the present invention, it is possible to apply a cooling block material that does not melt even when contacted with high temperature gas of 1,700 ° C. to almost the entire furnace wall. it can. Therefore, the furnace body has a structure in which the melting loss is extremely small, the unit consumption of refractory can be significantly reduced as compared with the conventional case, and the production of molten metal can be inexpensive.

Furthermore, while the secondary combustion rate of the carbonaceous material in the furnace body is increased, the heat-adhesion efficiency to the foaming slag in which the reduction reaction proceeds from the high temperature atmosphere is also significantly increased, and iron-based oxides like the conventional iron bath method are used. A finishing reduction period for improving the yield of the molten metal is not required, and the productivity of the molten metal can be improved and
Reduction of the basic unit of oxygen gas and carbonaceous material is realized.

On the other hand, strong and weak agitation by bottom blowing or side blowing is performed on a single-phase slag, and an optimal foaming slag having a bulk specific gravity of about 1 to 0.3 can be formed.
Further, it is possible to weaken the bubbling due to stirring in the vicinity of the refractory gutter formed at the bottom of the furnace body. Therefore,
The bulk specific gravity of the foaming slag at that part increases, the suspended carbonaceous material rises and decreases, and the dripping molten iron is not carburized, rather, the decarburizing action by the iron-based metal oxide has priority. The carbon-unsaturated melt is easily produced. As a result, it is possible to reduce the cost required for the molten steel treatment and the decarburization treatment performed subsequently.

In addition, since the iron-based oxide in the foaming slag is maintained at a high concentration, the molten iron is smoothly dephosphorized to improve the quality, and further, it is discharged through the deferred calming carbonaceous material separation slag section and the slag. In the slag thus formed, the carbonaceous material is almost eliminated and the iron-based metal oxide has an extremely low concentration, so that it is possible to suppress the basic unit of the carbonaceous material and the iron-based metal oxide required for producing molten iron.

In addition, since oxygen gas can be bottom-blown and desulfurization material such as limestone can be supplied to the iron bath in the molten metal storage furnace body, the molten metal is refined into desulfurized high-quality molten steel.

Furthermore, also in the smelting reduction furnace body and the molten metal storage furnace body,
It is possible to input iron-based scrap and easily increase the amount of molten iron.

The upper and lower split structures can be adopted for any furnace body, and in that case, if the lower part of the separate body with the refractory material repaired is prepared, the slag bath smelting reduction production equipment can be used for a certain period of time. The lower part can be replaced immediately when the operation is finished. Therefore, it is possible to improve productivity by shortening the time during which the furnace is closed for repairing the refractory.

〔Example〕

Hereinafter, with reference to the drawings, a slag bath-type smelting reduction manufacturing apparatus and a slag bath-type smelting reduction manufacturing method for a molten iron-based alloy of the present invention will be described in detail based on examples thereof.

As shown in FIG. 1, the slag bath type smelting reduction production apparatus is
An smelting reduction furnace body 1 having an airtight structure having a water cooling wall extending in the longitudinal direction and having a substantially rectangular cross section, and a molten metal storage furnace body 2 arranged at one end thereof are provided. In the furnace shell 1a of the smelting reduction furnace body 1, an upper space 3 is formed wide [see FIG. 2], and a slag bath type smelting reduction section 1A and a deferred calming carbonaceous material separation slag section 1B are formed. It And the furnace shell 1a
Except for the refractory 1c lined on the bottom 1b of the furnace, a cooling block material 1d having a water cooling block or a water cooling panel structure is lined almost all over the furnace wall to cool the furnace body 1 with water. The cooling block material 1d may be sprayed or mist water cooled.

The inner surface of the furnace body 1 is slag-lined by the slag 4 generated during operation, but in the newly installed furnace body, if castable refractory material is lined on the surface of the cooling block material 1d, It is convenient for raising the temperature at the start of operation.

On the other hand, the ceiling 1e of the slag bath smelting reduction section 1A is provided with a plurality (five in the figure) of upper blowing lances 5 for blowing oxygen gas or oxygen-containing gas into the furnace body 1, and the lower end 5 thereof is provided.
a is opened at almost the same height as the bubbling slag bath generated in the furnace body 1 so that the relative position between the bubbling slag 4 and the lower end 5a of the upper blowing lance 5 which may rise suddenly does not suddenly change. It is considered. This is because the upper space 3 is expanded as described above, and the sudden rise of the foaming slag 4 is suppressed. The interval between the upper blowing lances 5 is selected to be about 0.7 to 1.5 times the width W _{1 of the} slag bath [see FIG. 2] so that the foaming slag bath can be stirred appropriately and uniformly.

The ceiling portion 1e of the furnace body 1 is provided with a plurality of (two in the drawing) charging ports 6 through which ferrous metal oxides, carbonaceous materials, limestone, and the like are poured by a carrier gas such as nitrogen gas. The reason for adopting such a pouring form is that if iron-based metal oxide or the like is injected at a speed of several tens of meters / second by a high-pressure carrier gas, the scattering loss can be reduced rather than simple addition. is there. In addition, these entrances 6
Is preferably arranged near the top blowing lance 5.

The smelting reduction furnace body 1 is provided with an exhaust gas port 7 at its ceiling portion 1e or an upper part of the side shown in the drawing, but since it is directly connected to a fluidized bed type iron ore preliminary reduction furnace via an exhaust gas duct 8, the internal pressure is 1.4 atm. Above, it is preferably maintained at about 1.7 to 1.8 atm. In the high temperature furnace body 1 under such pressure,
The bottom portion 1b is provided with a plurality of (five in the figure) bottom blower openings 9 so that oxygen gas, nitrogen gas, or an inert gas can be blown during operation. The slag 4 is agitated by the nitrogen gas blown from the bottom blowing port 9 and the gas generated by the following smelting reduction reaction,
Usually, a slag having a bulk specific gravity of 2 or more is changed to a bulk specific gravity of about 1 to 0.3, and a foaming slag bath that diffuses and rises can be formed. Then, the coal-derived solid carbonaceous powder and granules charged from the charging port 6 are suspended in the foaming slag bath, and the iron-based powder is charged into the foaming slag bath and dissolved in the slag. The metal oxide causes a chemical reaction in a high temperature atmosphere, and while the coal is secondarily burned at a high burning rate, the iron-based metal oxide is melt-reduced with high heat deposition efficiency.

Also, a plurality of powdery iron-based metal oxides, powdery carbonaceous materials and dust collecting dust are blown into the slag bath with a carrier gas (for example, nitrogen gas) under the side wall 1f of the furnace body 1 (see FIG. 2). The horizontal blowhole 10 is provided [10 pieces in the drawing]. In addition, if there is a blow from the side tuyeres 10, the furnace body 1
The slag inside is agitated so that it can be whipped. Although the bottom blower mouth 9 and the side blower mouth 10 are arranged in the center between the upper blow lances 5 and 5, they may be provided directly below the upper blow lance 5.

By the way, instead of the iron-based metal oxide blown into the slag bath from the above-described charging port 6 and side blowhole 10, the iron ore,
You may make it blow in the granular material which is a chrome ore, a manganese ore, and these pre-reduction ores. In that case,
The carbon-unsaturated melt 11 stored in the melt storage furnace body 2 described later becomes a ferrochrome melt or a ferromanganese melt.

By the way, since the molten iron that has been smelt-reduced contacts the furnace shell 1a of the bottom 1b of the furnace body 1, the refractory 1c [second
(See the figure) is lined. In the refractory 1c, a refractory trough 12 that is inclined in the longitudinal direction toward the molten metal storage furnace body 2 is formed in a groove shape at the bottom of the furnace body 1. In the example of FIG. 2, the refractory gutter 12 is provided off the vertical center line 1g of the furnace body 1, and the bottom 1b reaching the refractory gutter 12 is provided.
The horizontal inclination of the cooling block material 1d is 5 degrees or more with respect to the horizontal line. In order to accelerate the inflow of molten iron into the refractory trough 12 and reduce melting loss, it is usually preferable to set the inclination angle to 20 to 40 degrees. By the way, as shown in FIG. 3, the refractory gutter 12 may be aligned with the vertical center line 1g.
In order to reduce the melting loss and to reduce the carbon concentration of the molten metal 11, it is preferable to set it as shown in FIG.

On the other hand, on the side opposite to the molten metal storage furnace body 2 in the smelting reduction furnace body 1, a deironization calming carbonaceous material separation slag portion 1B for calming the bubbling slag bath is defined by a partition wall 13. The partition wall 13 has such a height that the slag 4 in the slag bath-type smelting reduction section 1A can overflow, and the lower part is a refractory trough 12.
And a communication hole 13a communicating with the. The cooling block material 1d is also adhered to this partition wall 13, and the above-mentioned circulation hole 13a is formed in the refractory 1c extended below.

A plurality of [two in FIG. 2] blowing tuyere 14 for laterally blowing carbonaceous material and carrier gas or oxygen gas and cooling gas is attached to the side wall 1f of the deferred calming carbonaceous material separation and slag portion 1B. . By blowing from this blowing tuyere 14,
The overflowing foaming slag 4 is stirred, and the iron-based metal oxide in the slag 4 is reduced by the suspended carbonaceous material to a low concentration. The foaming slag 4 is calmed down below the blowing tuyere 14, the carbonaceous material in the slag 4 floats up, and the slag 4 becomes in a low iron oxide low carbonaceous material state. Slag outlet 15 for discharging the slag 4
However, the slag 4 that has been calmed down is provided at the lower part of the side wall 1f and is continuously discharged.

The exhaust gas port 7 provided in the furnace body 1 is an opening for discharging high-temperature exhaust gas of approximately 1,700 ° C. from the exhaust gas duct 8, and a fluidized bed type iron ore preliminary reduction furnace or the like is connected to the exhaust gas duct 8. If so, the heat can be reused.

The molten metal storage furnace body 2 described above is separated from the smelting reduction furnace body 1, and is provided with a molten metal outlet 16 that stores the molten metal 11 that flows down only from the refractory trough 12 and intermittently takes it out. A refractory 1c is lined in the lower part in contact with the molten metal 11 of the iron bath, and a cooling block material 1d is stuck in the upper part. When the molten metal outlet 16 is, for example, a sliding nozzle and the molten metal 11 is continuously discharged, the molten metal storage furnace body 2 can have a capacity smaller than that shown in the drawing.

Into the ceiling portion 1e of the smelting reduction furnace body 1 having the above-described structure, independent of the charging port 6 for pouring iron-based metal oxides, etc. ] Scrap addition port 17 may be provided.

According to the smelting reduction manufacturing apparatus having such a configuration, the molten iron-based alloy can be smelted and reduced by the slag bath method as follows.

In FIG. 1, when the temperature inside the furnace body 1 is raised to start the operation, nitrogen gas is blown in such an amount that the bottom blowhole 9 and the horizontal blowhole 10 are not blocked. Next, lump coke is charged from the charging port 6, and the lump coke is incandescently burned by the oxygen gas blown from the upper blowing lance 5. Subsequently, a mixture of lump coke and blast furnace slag is charged and the temperature is raised to a predetermined temperature of about 1,400 ° C or higher.

When entering the smelting reduction step, raw materials and auxiliary raw materials such as iron-based metal oxides, carbonaceous materials and limestone, which are close to the total required amount, are charged into the furnace body 1 through the charging port 6. Oxygen gas or oxygen-containing gas is continuously blown from the upper blowing lance 5, while oxygen gas, nitrogen gas, inert gas, or the like is blown from the bottom blowhole 9 and the side blowhole 10. If necessary, powdered iron-based metal oxide for addition, powdered carbonaceous material and dust are blown together with the carrier gas. With these blowing gases,
The slag 4 in the furnace body 1 is vigorously stirred and has a bulk specific gravity of 1 to 0.
The bubbling slag bath changes to 3, and rises to near the lower end 5a of the upper blowing lance 5.

The poured coal is suspended in the foaming slag 4, and the carbonaceous material chemically reacts with the iron-based metal oxide in the foaming slag bath to perform smelting reduction, and molten carbon unsaturated carbon is produced. On the other hand, carbon monoxide gas is generated from the carbonaceous material by the chemical reaction, and the carbon monoxide gas is secondarily burned to carbon dioxide gas, and the atmosphere in the furnace body 1 is maintained at a high temperature. By secondary combustion 1,
The carbon dioxide gas at 700 ° C. is led from the exhaust gas port 7 through the exhaust gas duct 8 to the iron ore preliminary reduction furnace.

Carbonaceous materials, iron-based metal oxides, limestone, and oxygen gas consumed by such chemical reactions are introduced into the charging port 6 and the upper blowing lance 5.
It is replenished from the bottom and bottom blowers 9 and the side blowers 10. Molten iron produced in the bubbling slag bath is dropped. In the vicinity of the refractory gutter 12, the stirring action is weakened, and therefore,
The bulk specific gravity of the slag 4 is large, the carbonaceous material floats up, and the suspended carbonaceous material in the slag 4 disappears. The reaction between the iron-based metal oxide and the molten iron takes precedence over the reaction of the dropping molten iron with the carbon material to be carburized. As a result, the molten iron becomes a carbon unsaturated molten metal 11 and is collected in the refractory trough 12. Although the smelting reduction proceeds in this way, the concentration of iron oxide contained in the foaming slag 4 in the vicinity of the refractory gutter 12 is high, so the molten metal 11 in contact with them is dephosphorized, which is convenient. .

On the other hand, the foaming slag 4 in the furnace body 1 flows over the partition 13 into the deironization calming carbonaceous material separation slag portion 1B. Although the slag 4 is not affected by the gas blown from the bottom tuyere 9, the slag 4 is melted and reduced by blowing carbonaceous material added to oxygen gas or nitrogen gas from the blown tuyere 14, and molten iron is generated there. Then, it is dropped to form a carbon-unsaturated melt 11.
When collected in the refractory trough 12 below the deferred calming carbonaceous material separation slag portion 1B, it is led out to the molten metal storage furnace body 2 through the flow holes 13a of the partition wall 13. Then, when the foaming slag 4 in the deferred calming carbonaceous material separation slag portion 1B descends from the blowing tuyere 14, the stirring is weakened and calmed down, and the bulk specific gravity increases and the suspended carbonaceous material floats. With the suspended carbonaceous material, slag 4
The iron-based metal oxides therein are also reduced. As a result, the suspended foaming slag 4 has almost no suspended carbonaceous material, and only a small amount of low-concentration iron oxide remains. The soothed slag 4 is continuously discharged from the outlet 15 and then processed. Also in this case, the unit consumption of carbonaceous materials and iron-based metal oxides can be reduced. On the other hand, the molten metal 11 stored in the molten metal storage furnace body 2 is intermittently taken out from the molten metal outlet 16.

By the way, in the smelting reduction furnace body 1 in operation, the amounts of raw materials and auxiliary raw materials to be fed are adjusted so that the height of the foaming slag 4 is almost at the same level as the lower end 5a of the upper blowing lance 5 as shown in the figure. It That is, the amount of carbonaceous material suspended in the foaming slag 4 is such that 20% or more of the weight of the slag is always retained. On the other hand, the amount of bottom blowing gas from the bottom blowing tuyeres is
The amount of gas blown into the slag is set to 3 to 30%, the slag 4 is appropriately stirred and foamed, and the MgO and Al ₂ O ₃ in the slag 4 are also agitated.
The total amount of and is suppressed to 23% or less. Further, the ratio of CaO / SiO ₂ contained in the slag is maintained at about 0.8 to 1.9, and the ratio of the total weight of the ore and the carbonaceous material added to the slag phase from the charging port 6 is maintained at 60% or more. As a result, heat transfer efficiency is improved. Then, the suspended carbonaceous material is burned at a high secondary combustion rate, and the carbon dioxide gas atmosphere is maintained at about 1,700 ° C. The carbonaceous material may be granular coal, anthracite or coke, but low cost steam coal is used. Further, as the gas blown from the bottom blowing port 9, nitrogen gas, air or oxygen gas is used, and in the case of oxygen gas, liquefied natural gas (LNG) for cooling is also used. In the case of nitrogen gas and air, it is advisable to preheat and blow them.

FIG. 4 shows an apparatus in which a pan-shaped molten metal storage furnace body 18 is connected to the smelting reduction furnace body 1. This is provided with a semi-circular bottom portion 18a, and a refractory 1c is lined in a portion for storing the molten metal 11 that has flowed through the refractory trough 12 as an iron bath. A cooling block material 1d is lined on the upper portion including the ceiling portion 18b, and the upper space is connected to the smelting reduction furnace body 1. In addition, the bottom portion 18a of the molten metal storage furnace body 18
Is provided with a bottom blower port 19 for blowing oxygen gas into an iron bath, and a ceiling port 18b is provided with an input port 20 for supplying desulfurizing material such as limestone. Further, there is a tap hole 16 slightly above the bottom portion 18a so that the molten metal 11 intermittently blown to the bottom can be taken out while leaving the seed water.

In the molten metal storage furnace body 18 having such a configuration, the carbon-unsaturated molten metal 11 dephosphorized from the smelting reduction furnace body 1 in operation is used.
Flows down and is stored in the bottom portion 18a. When the stored amount reaches a specified amount, desulfurization material such as limestone is supplied from the charging port 20 together with nitrogen gas which is a carrier gas. In this example,
In addition to limestone, silica stone is charged from the charging port 20,
Iron-based scrap or iron ore as a coolant is charged from a scrap addition port 21 separately provided in the ceiling portion 18b. Then, liquefied natural gas is blown as oxygen gas and cooling gas from the bottom blowing port 19. By this bottom blowing operation, the molten metal 11 is desulfurized together with decarburization and refined into high quality molten steel.

In this case, the slag 22 formed of the introduced limestone, silica stone, and impurities of iron ore floats on the iron bath. Slag 2
The basicity of 2 is maintained as high as 3 to 5 which is similar to that of a converter.
Since the iron oxide concentration in the slag 22 is low due to bottom blowing,
Desulfurization proceeds with decarburization of the molten metal 11. Then, since the exhaust gas containing carbon monoxide gas as a main component generated by decarburization enters the foaming slag bath of the smelting reduction furnace body 1, the lime in the slag 22 can be utilized as a constituent material of the foaming slag 4, Carbon monoxide gas is also used. In addition,
You may make it input manganese ore from the input port 20.

By the way, also in the case of FIG. 1 and FIG. 4 described above,
Separately from the loading port 6 of the ceiling 1e, the scrap addition port 1
7 and 23 are provided and iron-based scrap is introduced from there, the iron oxide melt-reduced in the foaming slag bath can be extremely efficiently converted into a large amount of carbon-unsaturated molten iron. . At that time, the scrap also functions as a coolant. Further, by injecting chromium ore or manganese ore and powders or granules of their pre-reduced ore into the foaming slag bath from the charging port 6 or the side blowhole 10, it is possible to produce ferrochrome molten metal or ferromanganese molten metal. .

By the way, as shown in FIG. 5, the smelting reduction furnace body 1 shown in FIG. 1 has a structure that can be divided into an upper furnace body 1U and a lower furnace body 1D, and fire resistance of the lower furnace body 1D used before during operation. It is convenient to be able to repair the item 1c.
The lower furnace body 1D is a portion including the refractory gutter 12,
The upper furnace body 1U is a portion lined with a foaming slag bath and a cooling block material 1d which is in contact with a high temperature gas. With such a detachable split structure, the refractory 1c need to be refilled or repaired once every several tens of days without suspending the operation of the furnace body 1 for a long time. As shown in FIG. 5, the entire lower furnace body 1D of the smelting reduction furnace body 1 is placed on a plurality of carriages 24 (one shown in the figure) arranged in the longitudinal direction of the furnace body 1. It is possible to raise the lower furnace body 1D by hydraulic power or electric power at a predetermined position to join the flange portions 25, 25 to be integrated with the upper furnace body 1U. In addition, also in the molten metal storage furnace bodies 2 and 18, the upper furnace bodies 2U and 18U and the lower furnace bodies 2D and 18
With a similar structure such as D, a vertically divided structure can be obtained, and the flange portions 26, 26 [see FIGS. 1 and 4]
Then, the refractory 1c can be repaired separately from the operation.

Here, the shape of the smelting reduction furnace body 1 will be described with reference to FIG. The ratio H ₁ of the width W ₁ of the frothing slag bath and the height H ₁ of the frothing slag bath is the region where the frothing slag 4 is generated.
By setting / W ₁ to 1, heat loss can be minimized. However, H ₁ / W ₁ > 1 is preferable in order to blow oxygen gas, nitrogen gas or an inert gas from the bottom blowing port 9 so that the slag 4 can be effectively stirred and foamed. On the other hand, Yokobuki tuyere 1
When oxygen gas, nitrogen gas or inert gas is blown from 0, the blowing distance becomes insufficient as the width W ₁ of the foaming slag bath becomes wider, so that H ₁ / W ₁ = 0.6 to 3.0 or narrower than that. 0.8 to 2.0 is preferable.

On the other hand, in order to prevent the bubbling slag 4 from flowing into the exhaust gas port 7 and maintain both the secondary combustion rate and the heat-transfer efficiency at a high level, the uppermost surface of the slag 4 is almost at the lower end 5a of the upper blowing lance 5. Contact is desirable. Therefore, the width W ₂ of the upper space 3 of the foaming slag bath is 1.2 to 1.5 W ₁ ,
The abnormal rise of the foaming slag 4 is suppressed.

Further, if the exhaust gas above the bubbling slag bath flows toward the exhaust gas port 7 at a high superficial velocity, the ore and carbonaceous powder poured from the charging port 6 scatter and flow out from the exhaust gas duct 8. The percentage to do will increase. In consideration of such a situation, in order to improve the productivity of the molten metal with respect to the total furnace capacity, the ratio L / W of the total length L of the smelting reduction furnace body 1 (see FIG. 1) and the width W ₁ of the foaming slag bath is L / W. It is desired to increase ₁ and L / W ₁ > 4 is usually adopted. In that case, the number of top blowing lances 5 may be increased appropriately.

On the other hand, if the amount of exhaust gas generated per unit volume of the bubbling slag bath is constant, the above-mentioned superficial velocity is equal to the cross-sectional area S ₁ [= W ₁ × H ₁ ] of the bubbling slag bath and the cross-sectional area S of the upper space 3. ₂
It is determined by the ratio S ₂ / S ₁ and L / W ₁ with [= W ₂ × H ₂ ]. Note that H ₂ is the height of the upper space 3. Therefore, if determined the S ₂ / S ₁ = 0.6~3.0 made as foaming width W ₂ of width W ₁ and the upper space 3 of the slag bath, froth height H ₂ of the height H ₁ and the upper space 3 of the slag bath Good. L / W ₁ >
If the number becomes 6, it will be necessary to provide a plurality of exhaust gas ports 7.

The phosphorus concentration of the molten metal 11 produced in the deferred calming carbonaceous material separating and slag portion 1B is the same as that of the molten metal 1 produced in the slag bath smelting reduction portion 1A
It becomes higher than the phosphorus concentration in 1. The iron oxide concentration contained in the foaming slag bath in the slag bath type smelting reduction section 1A at a high concentration is used for the smelting reduction in the foaming slag 4 in the deferred calming carbonaceous material separation slag section 1B. Because it is low. Therefore, the circulation hole 13a of the partition wall 13
From the above, a hot water pool (not shown) is provided at a position of the refractory gutter 12 which is located at a slight distance near the slag bath smelting reduction section 1A, and a lime-based dephosphorization material and oxygen gas or mill scale are provided. You may make it dephosphorize by blowing in from the bottom part of a basin part.

Although a foaming slag bath is formed by bottom blowing or side blowing, if the bulk specific gravity of the slag 4 is adjusted to change to 0.3 to 1.0, the secondary combustion rate and the heat-adsorption efficiency of the carbonaceous material can be increased. Are as described above. The bulk specific gravity and fixed carbonaceous material distribution of the bubbling slag bath are determined by the addition rate of iron ore and carbonaceous material, the gas generation rate per unit slag amount determined by the oxygen gas feed rate, and the composition and temperature of the slag. It can be adjusted by the furnace pressure, the bottom blown specific gravity, the side blown specific gravity, the top blown lance structure, and the spatial distribution of the slag bath depending on the strength of stirring.

By the way, when comparing the conventional iron bath method and the slag bath method of the present invention, in the case of smelting reduction by the iron bath method, oxidation in the slag by carbon dissolved in iron at the slag / molten metal interface The reduction reaction of iron proceeds in parallel with the reduction reaction of iron oxide in the slag by the carbon suspended in the slag, and the sum of the amounts of molten iron produced by both reactions becomes the production amount. In the case of slag reduction by the slag bath method, the former contribution is close to zero, and the production amount decreases. However, as the furnace body gets larger, the contribution of the amount produced by the interfacial reaction between the slag and the molten metal becomes extremely small,
It is possible to reduce the difference in the production volume per unit volume of both the iron bath and the foaming slag to less than 20%.

In the case of the slag bath method, the reduction in productivity per total volume by providing the deironing calming carbonaceous material separating and slag portion 1B in the smelting reduction furnace body 1 is based on the need for a finishing reduction period in the iron bath method. It is smaller than the decrease in productivity. In the case of smelting reduction of ferrochrome and ferromanganese, slag /
Since the reduction reaction does not proceed at the boundary surface of the molten metal, it can be said that the slag bath method has higher productivity per unit volume in terms of both volumes of the iron bath and the foaming slag.

The heat loss due to the removal of heat from the furnace body is smaller in the iron bath furnace where the refractory is lined on the entire surface than in the water-cooled slag bath furnace. However, when the volume of the furnace body is increased, the slag bath method is superior in the total thermal efficiency in terms of the product of the secondary combustion rate and the heat deposition efficiency.

In the slag bath method, the average temperature of the foaming slag bath is 1,400 ~
It is necessary to keep the temperature at about 1,600 ℃ for controlling the height of the foaming slag. However, in terms of the heat content of the entire bath, the iron bath furnace is larger than the slag bath furnace, and the iron bath plays the role of a thermal buffer. That is, since the slag bath method has a larger temperature fluctuation range due to the same disturbance, it is necessary to enhance the measurement control system by increasing the number of temperature measurement points.

When melting scrap, the slag bath method is significantly superior in refractory material, carbon material, and oxygen consumption rate, compared to the iron bath method in which carbon material is blown into the iron bath, for example, in JP-A-61-213310. Compared with the slag / iron bath method described, the unit consumption of refractory is remarkably good, and the unit consumption of carbonaceous materials and oxygen is slightly superior. However, since the slag bath method has a small heat content in the bath, it can be applied only when continuously charging scraps of uniform thickness and shape such as shearing scraps and Dalai powder. With the iron bath method in which carbon material is blown, irregularly shaped scraps such as heavy dust can be batch-charged, so it must be said that the slag bath method is inferior in terms of the degree of freedom in selecting the type of scrap and the charging method. I don't get it.

An example of the present invention is shown in Table 1 and FIGS.
Description will be given with reference to the drawings.

The length of the slag bath smelting reduction section 1A shown in FIG. 1 is 15
m, that of the deferred calming carbon material separation slag portion 1B is 1.5 m. The width W ₁ of the foaming slag bath shown in FIG. 2 is 3.5 m, the height H ₁ is 4 m, the width W ₂ of the upper space 3 is 4.5 m, and its height is 4 m.
In the water-cooled smelting reduction furnace body 1, there are 5 special porous top blowing lances 5 for secondary combustion, 6 bottom blowing tuyeres 9 and 12 lateral blowing tuyeres 10 at a position 3 m below the slag bath surface. The book is arranged.
Further, the furnace body 1 is divided into upper and lower halves, and the inner surface is castable refractory and is coated with a thickness of 40 mm.

After preheating the lower furnace body 1D of the furnace body 1 with a burner, the upper and lower parts are connected to each other to allow a minimum amount of nitrogen gas so that the bottom blower mouth 9 and the horizontal blower mouth 10 are not blocked, and the coke from the charging port 6 Then, oxygen gas is blown from the top blowing lance 5. After the lump coke became incandescent, the mixture of the lump-like coke and the blast furnace slag was added, and the addition was continued while increasing the blast furnace slag ratio of the mixture. After 4 hours, the total amount of slag was about 150 tons, of which the amount of carbon was 40 tons and the slag temperature was 1,50.
When the temperature reached 0 ° C, the coke was switched to steam coal and started to be charged, and then iron ore was charged to start smelting reduction. The exhaust gas is guided to a fluidized bed type preliminary reduction furnace, and the iron ore is heated to be partially reduced, and the preliminary reduced iron ore is hot-heated.
It was charged directly from the charging port 6.

As a result, the temperature and reduction rate of the cast iron ore gradually increased and reached a steady state after about 200 hours. Therefore,
Table 1 shows 100 for each of Case I and Case II.
The result of having carried out the test of time is shown. At that time, the internal pressure of the furnace was 1.7 to 1.8 atm, and the molten metal was stored in a molten metal storage furnace body having an internal volume of 30 m ³ and was discharged at intervals of 80 minutes. In the operation for 415 hours, the maximum erosion depth of the refractory trough was 45 mm.

Case III shown in Table 1 is a comparative example by a carbonaceous material suspended mass slag iron bath smelting reduction method using a converter. A 320 ton converter with an internal volume of 310 m ³ after refractory lining, a special porous top blow lance for secondary combustion, 4 bottom blowers, 4 side blowers about 1.5 m above the surface of the molten metal. Was placed. 100 tons of hot metal was charged as the seed water, and while flowing the minimum amount of gas that did not block the bottom and side blower mouths, pour coke from the charging port at the top of the furnace and oxygen gas from the top blowing lance. The blast furnace slag addition was continued while blowing. After about 3 hours, the amount of slag in the furnace is about 40 tons, and the amount of carbonaceous material in the slag is about
After 10 tons of molten metal temperature reached about 1,450 ℃, the coke was switched to steam coal, the pouring of iron ore was started, and the smelting reduction was started. When the exhaust gas was led to the preliminary reduction fluidized bed and the iron ore was heated and partially reduced, the temperature and the reduction rate of the iron ore poured gradually increased. A steady state was reached after about 200 hours, so a 100-hour test was performed. The internal pressure of the converter was 1.7 to 1.8 atm. As a form of continuous operation, the steady smelting reduction period is set to about 2 hours, and the top blowing gas amount, the side blowing gas amount, the bottom blowing gas amount and the iron-based metal oxides and the carbonaceous material addition amount are set to about 2 / It was dropped to No. 3, and during this period, the molten metal was discharged from the furnace belly, and then the molten metal was discharged from the furnace.

The amount of gas, the amount of ore, and the amount of coal added in Table 1
The weight of slag, the amount of carbonaceous material in the slag, the secondary combustion rate, and the heat transfer efficiency are average values during the entire test period. After 310 hours of operation, the erosion thickness of the refractory at the slag / melt interface was 120-150 mm. The thickness of the refractory material in contact with the slag was 170 to 200 mm.

Comparing Cases I and II in the slag bath smelting reduction manufacturing method of the present invention with Case III of the conventional method, the present invention is (1) Even if the water cooling structure above the part that contacts only the slag by the conventional method,
If you multiply by the area of refractory, the basic unit of refractory is significantly reduced.

(2) Since the secondary combustion rate is maintained high, the unit consumption of carbonaceous materials and oxygen gas is significantly reduced.

The above is clear, and it can be seen that the intended purpose was achieved.

Next, the results of applying the present invention to scrap melting will be described. The equipment is the same as in the case of smelting reduction, but the scrap addition port 17 is provided independently of the charging port 6. The procedure for starting up the equipment is similar, but when the total amount of slag is about 120 tons, the amount of carbonaceous material in the slag is about 10 tons, and the slag temperature reaches about 1,500 ° C, the coke is switched to steam coal and started to be charged. ,
Then, sheared scraps were continuously fed through the scrap addition port. The pressure inside the furnace was normal pressure, and the exhaust gas was led to the exhaust gas holder. Then, the generated molten metal was discharged at intervals of 30 minutes.

2nd average value of data over 50 taps or 25 hours
Shown in Case IV of the table. Case V is an example using a converter, and the equipment and startup procedure are almost the same as in Case III. However, after the amount of slag in the furnace was about 40 tons, the amount of carbonaceous material in the slag was about 7 tons, and the molten metal temperature reached 1,500 ° C, medium-sized scraps and lightweight scraps were mixed and charged all at once. Top blowing for about 35 minutes
After continuing horizontal blowing / bottom blowing and pouring carbonaceous material, stop the top blowing, tap the hot water in the inversion furnace, tap the slag, and then charge the scrap for 15 minutes. It was The data over 50 taps or 42 hours is shown in Table 2, case V. In both cases IV and V, the iron oxide content in the slag is low because the iron oxide content in the scrap is small, and as a result, the carbonaceous material ratio in the slag required to prevent slopping is Was lower than

In case IV of the present invention, the secondary combustion rate is maintained higher than in case V of the conventional method. As a result, it is clear that the carbonaceous material and the oxygen gas consumption rate are reduced. However, the amount of carbon, phosphorus, and sulfur contained in the molten metal (%), the iron oxide content in the discharged slag, and the carbonaceous material concentration are particularly advantageous. I can not recognize such a point. That is, it can be seen that the advantage in the case of scrap melting only according to the present invention is smaller than that in the case of smelting reduction. In addition, compared with melting reduction of iron-based metal oxides, melting scrap requires almost no energy required for reducing iron oxide, so the basic unit of carbonaceous material and oxygen gas becomes smaller, Sex is significantly enhanced.

If higher elasticity of productivity is required, if a carbonaceous material is added in an ordinary converter to increase the scrap blending ratio, both the secondary combustion rate and the heat generation efficiency are much lower than those of the present invention. Not relevant. In such a case, the present invention is used,
If the melting of scraps is performed in parallel in the same furnace while performing smelting reduction, cases I and II described in Table 1
It is possible to meet with any productivity requirement in the middle of the case IV described in Table 2 with high thermal efficiency, and it is possible to obtain a predetermined value in a converter as a post-process of the slag bath smelting reduction method of the present invention. If the scrap is used in a ratio necessary to match the end point temperature and the components of the above, the thermal efficiency of the total process can be remarkably improved.

That is, the efficiency of the present invention is remarkable when the slag bath smelting reduction is carried out exclusively and when the scrap is melted in parallel with the slag bath smelting reduction.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a slag bath type smelting reduction production apparatus for molten iron-based alloy of the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 is a position of a refractory gutter. 4 is a longitudinal sectional view of a slag bath type smelting reduction production apparatus equipped with different molten metal storage furnace bodies, and FIG. 5 is a sectional view of a smelting reduction furnace body having a vertically divided structure. . 1 ... smelting reduction furnace body, 1A ... slag bath type smelting reduction section,
1B: Deferred iron calming carbon material separation slag section, 1D, 2D, 18D
...... Lower furnace body, 1U, 2U, 18U ...... Upper furnace body, 1b
...... Lower part, 1e ...... Ceiling part, 2 ...... Melted metal storage furnace body, 4,
22 …… Slug, 5 …… Kabuki lance, 6 …… Billing entrance, 7
...... Exhaust gas outlet, 9 ...... Bottom blower mouth, 10 ...... Side blower mouth, 1
1 ... Molten metal (iron bath), 12 ... Refractory gutter, 13 ... Bulkhead, 14 ... Blowing tuyere, 15 ... Slag spout, 16 ... Spout spout, 17, 21, 23 ... Scrap addition Mouth, 18 ...
Molten metal storage furnace body, 18a ... bottom, 18b ... ceiling, 1
9 ... Bottom blower mouth, 20 ... Input port.

Claims (11)

[Claims] 1. A smelting reduction furnace body having an airtight structure having a substantially rectangular cross section and having a water cooling wall extending in the longitudinal direction, and
A smelting reduction manufacturing apparatus comprising a molten metal storage furnace body arranged at one end thereof, wherein the smelting reduction furnace body has an exhaust gas port at a ceiling portion or an upper side portion thereof, and a slag bath type smelting reduction unit and The slag bath type smelting reduction unit is defined as an iron calming carbonaceous material separation slag unit, and in order to smelt and reduce the iron-based oxide in the slag by the solid carbonaceous material suspended in the foaming slag bath, the furnace is used. On the ceiling of the body, top blowing lance for blowing oxygen gas or oxygen-containing gas, iron-based metal oxide,
A charging port for pouring carbonaceous materials and limestone, etc. is provided, and the side wall of the furnace body is provided with a horizontal blowhole for blowing powdered metal oxide, powdered carbonaceous material, dust, etc., and at the bottom of the furnace body. Is equipped with a bottom blower port for blowing oxygen gas, nitrogen gas, or an inert gas into the slag bath, and the molten metal produced by the smelting reduction is passed through at the bottom of the blower port. A refractory gutter that is inclined in the longitudinal direction is formed toward the slag, and at the other end of the furnace body, the slag of the slag bath type smelting reduction part can overflow and the bottom part is the refractory A partition wall that communicates with the gutter is provided with the separated deferred calming and calcining carbon material separating and slag section, and the side wall of the deferring and calming carbon material separating and slag section has carbon material and carrier gas or oxygen gas and cooling. Blow tuyere that blows gas sideways and this blow A slag outlet is provided at the bottom of the tuyere to discharge the calmed slag, and the molten metal storage furnace body stores the molten metal flowing down from the refractory trough, and the stored molten metal. A slag bath type smelting reduction production apparatus for molten iron-based alloys, characterized in that it is provided with a tap opening for taking out. 2. A scrap addition port for introducing iron-based scrap is provided in the ceiling portion of the smelting reduction furnace body, in addition to a charging port for introducing iron-based metal oxide. 1. A slag bath-type smelting reduction production apparatus for molten iron-based alloy according to 1. 3. The bottom of the molten metal storage furnace body is provided with a bottom blower port for blowing oxygen gas into an iron bath, and the ceiling part is provided with an input port for supplying desulfurizing material such as limestone. The slag bath type smelting reduction manufacturing apparatus for molten iron-based alloy according to claim 1. 4. A scrap addition port for introducing iron-based scrap is provided in the ceiling of the molten metal storage furnace body in addition to a supply port for supplying desulfurization material. A slag bath type smelting reduction production apparatus for the molten iron-based alloy described. 5. The smelting reduction furnace body has a structure that can be divided into a lower furnace body containing a refractory gutter and an upper furnace body in contact with a foaming slag bath and gas. A slag bath-type smelting reduction production apparatus for molten iron-based alloy according to claim 4. 6. The molten metal storage furnace body has a structure capable of being divided into a lower furnace body which is in contact with the iron bath and an upper furnace body which is not in contact with the iron bath. 4. A slag bath-type smelting reduction production apparatus for molten iron-based alloy according to any one of 4 above. 7. A slag-bath type smelting reduction of the furnace body by pouring iron-based metal oxides, carbonaceous materials, limestone, etc. into a closed smelting reduction furnace body having a substantially rectangular cross section and extending in the longitudinal direction. Oxygen gas or oxygen-containing gas was blown into the bubbling slag bath generated in the section, and the molten metal in which the iron-based metal oxide poured into the bubbling slag bath was melt-reduced was connected to one end of the melting reduction furnace body. The molten metal is stored in the molten metal storage furnace body, and the molten metal is intermittently discharged, while the partition wall for overflowing the partition for forming the deferred calming carbonaceous material separation sludge formed at the other end of the smelting reduction furnace body is overflowed. The iron-based alloy is characterized in that the foamed slag that has been blown is agitated by a carbon material and carrier gas or oxygen gas and a cooling gas that are blown sideways to promote smelting reduction and then calmed, and the calmed slag is discharged. Molten metal slag bath Smelting reduction manufacturing method. 8. A slag bath type smelting reduction of an iron-based alloy melt according to claim 7, wherein chromium oxide or manganese oxide is poured into the smelting reduction furnace in addition to the iron-based metal oxide. Manufacturing method. 9. The slag bath type smelting reduction production method for molten iron-based alloy according to claim 7, wherein iron-based metal oxide is poured into the smelting-reduction furnace while iron-based scrap is introduced. . 10. The slag bath type melt reduction production method for molten iron-based alloy according to claim 7, wherein desulfurization material is supplied into the molten metal storage furnace body and oxygen gas is blown into the iron bath. 11. The method for supplying a desulfurizing material into the molten metal storage furnace body while charging an iron-based scrap.
11. A slag bath smelting reduction production method for molten iron-based alloy as set forth in item 10.