CN114040987B

CN114040987B - Electrolytic smelting furnace

Info

Publication number: CN114040987B
Application number: CN202080044047.1A
Authority: CN
Inventors: 宇多信喜; 小城育昌; 野间彰
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2019-06-21
Filing date: 2020-01-20
Publication date: 2023-02-28
Anticipated expiration: 2040-01-20
Also published as: JP7377633B2; CN114040987A; WO2020255465A1; JP2021001368A

Abstract

The electrolytic smelting furnace is provided with: a furnace main body into which iron ore is introduced; a furnace bottom electrode provided at the furnace bottom in the furnace main body; and a plurality of upper electrodes provided above the hearth electrode in the furnace body and having an electrode body for electrowinning the molten iron ore. At least one of the upper electrodes is a melting electrode having a heating portion for heating and melting iron ore to obtain molten iron ore inside the electrode body. This enables smooth start of operation of the electrolytic smelting furnace.

Description

Electrolytic smelting furnace

Technical Field

The invention relates to an electrolytic smelting furnace.

The present application claims priority based on Japanese application No. 2019-115566 filed on 21/6/2019, and the contents thereof are incorporated herein by reference.

Background

As a technique for refining iron ore, for example, heat treatment using a blast furnace or a converter has been widely used. In this method, iron ore as a metallic material and coke as a reducing material are burned in a furnace. In the furnace, carbon contained in the coke takes oxygen from iron to generate heat, carbon monoxide, and carbon dioxide. By this reaction heat, iron ore is melted to produce pig iron. Then, oxygen and impurities are removed from the pig iron to obtain pure iron.

Here, the above method requires a large amount of carbon including coke, and thus the amount of carbon monoxide and carbon dioxide generated increases. With the recent trend toward more stringent countermeasures against air pollution, there has been a demand for refining techniques for suppressing the amount of carbon-containing gas generated. As an example of such a technique, an electrolytic smelting method described in patent document 1 below can be given.

In the electrolytic smelting method, a voltage is applied to the inside of a furnace having a flat hearth with molten iron ore interposed between a hearth electrode and an upper electrode. Thereby, a molten electrolyte including a slag component is deposited on the upper electrode side, and molten iron (pure iron) is deposited on the bottom electrode side. As an example, a metal material including iron, chromium, vanadium, and tantalum is used for the upper electrode. As shown in fig. 21, the upper electrodes T are generally rod-shaped and extend in the vertical direction, and are arranged in a grid pattern with intervals in the horizontal plane. As the hearth electrode, a metal material made of molybdenum is used as an example.

Prior art documents

Patent document

Patent document 1: description of U.S. Pat. No. 8764962

Disclosure of Invention

Problems to be solved by the invention

However, in the above-described electrolytic smelting method, the amount of heat radiated through the wall surface of the furnace becomes large. Further, since the iron ore before melting is not electrified, an electrode for electrolytic smelting cannot be used. Therefore, it is sometimes difficult to uniformly melt the iron ore charged into the furnace at the start of refining. This hinders smooth operation of the electrolytic smelting furnace.

The present invention has been made to solve the above problems, and an object thereof is to provide an electrolytic smelting furnace capable of smoothly starting operation.

Means for solving the problems

An electrolytic smelting furnace according to an aspect of the present invention includes: a furnace main body into which iron ore is introduced; a furnace bottom electrode provided at a furnace bottom in the furnace main body; and a plurality of upper electrodes provided above the furnace bottom electrode in the furnace main body, wherein at least one of the upper electrodes is a melting electrode having an electrode for electrolytic smelting and a heating unit provided in the electrode for electrolytic smelting to heat and melt the iron ore and to obtain the molten iron ore, and wherein the electrode for electrolytic smelting and the furnace bottom electrode are energized to electrolytically smelt the molten iron ore.

According to the above configuration, before the electrolytic smelting, the iron ore can be heated and melted by the heating portion of the melting electrode. This makes it possible to easily produce molten iron ore. Further, since the heating portion is provided inside the electrode for electrolytic smelting, the size and the shape of the electrode for melting can be suppressed to be small. This can further improve the degree of freedom in the arrangement of the upper electrode.

In the above electrolytic smelting furnace, the heating portion may include: a cylindrical torch body disposed on an inner peripheral surface of a through hole formed in the electrowinning electrode; and a plasma torch electrode inserted through an inner circumferential side of the torch body, and configured to melt the iron ore by a plasma jet formed by applying current between the torch body and the plasma torch electrode in a state before the iron ore is melted.

According to the above configuration, the plasma jet is formed by supplying electricity between the torch body and the plasma torch electrode in a state before the iron ore is melted. The iron ore can be efficiently melted by the plasma jet.

In the above electrolytic smelting furnace, the heating unit may heat the molten iron ore by a plasma jet formed by passing electricity between the plasma torch electrode and the hearth electrode in a state where the iron ore starts to be molten.

According to the above configuration, in a state where the iron ore starts to be melted, the plasma jet is formed by supplying electricity between the plasma torch electrode and the hearth electrode. The iron ore that has started to melt can be further melted by the plasma jet, and the temperature can be raised and homogenized. Further, even when the molten iron ore is solidified due to, for example, interruption of the operation, the molten iron ore can be remelted by the heating unit. Thus, the electrolytic smelting operation can be immediately restarted.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include: a refining power supply unit for applying a voltage between the hearth electrode and the upper electrode; and a starting power supply unit which is provided independently of the refining power supply unit and applies a voltage between the hearth electrode and the plasma torch electrode.

Here, the voltage required at the start of operation (i.e., when melting the iron ore) is larger than that at the time of refining. According to the above configuration, the refining power supply unit and the starting power supply unit are provided independently. Therefore, for example, compared to a configuration in which the refining power supply unit and the starting power supply unit are not independent, it is possible to suppress variation in voltage generated in each power supply unit. Thus, the electrolytic smelting furnace can be operated more stably.

In the electrolytic smelting furnace, the heating unit may melt the iron ore by a flame formed of a hydrogen-containing mixed gas in a state before the iron ore is melted.

According to the above configuration, the hydrogen-containing combustion gas is supplied from the cylindrical pipe, and the flame is formed from the combustion gas, whereby the molten ore can be heated easily and quickly.

In the electrolytic smelting furnace, the heating unit may be configured to extinguish a hydrogen-containing mixed gas in a state where the iron ore starts to be melted and supply the hydrogen-containing mixed gas to the molten iron ore, thereby stirring the molten iron ore.

According to the above configuration, the molten iron ore can be stirred by supplying the mixed gas for melting the iron ore to the molten iron ore in a flameout state. This can homogenize the molten iron ore. In addition, since a dedicated device for stirring is not required, the structure of the device can be simplified. This can reduce the manufacturing cost and the operating cost.

In the above-described electrolytic smelting furnace, at least one of the upper electrodes may be formed with an input hole portion that vertically penetrates the upper electrode to introduce the iron ore into the furnace main body.

According to the above configuration, the iron ore can be smoothly charged into the furnace main body through the charging hole. Further, since the charging hole is formed in a part of the upper electrode, the number of the upper electrodes and the density of the upper electrodes can be increased as compared with a case where a charging port for charging iron ore is separately provided.

In the above electrolytic smelting furnace, the furnace main body may further include: a discharge recess which is recessed further downward from the furnace bottom; a discharge passage that communicates the discharge recess with the outside; and an opening/closing unit that opens and closes the discharge path.

According to the above configuration, the molten iron produced by the electrolytic smelting can be easily taken out of the furnace main body through the discharge recess and the discharge passage. In particular, since the opening/closing portion is provided in the discharge passage, the molten iron can be more easily taken out only by opening the opening/closing portion.

In the above electrolytic smelting furnace, the discharge passage may be provided above a bottom surface of the discharge recess, and an outer periphery heating device that covers a portion of the discharge recess below the discharge passage from outside may be provided in the discharge recess.

According to the above configuration, since the discharge passage is provided above the bottom surface of the discharge recess, only the component containing the impurity is precipitated on the bottom surface side, and only the component containing no impurity can be taken out to the outside through the discharge passage. The portion below the discharge passage is covered from the outside by the outer periphery heating device. Therefore, for example, a component solidified in the discharge recess portion when the operation is interrupted can be melted immediately when the operation is resumed. Thus, the electrolytic smelting furnace can be operated more smoothly.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include a discharge passage heating portion that is provided in the discharge passage and that changes viscosity by heating the molten iron ore or a conductive refractory material that forms a flow passage and that flows through the discharge passage.

According to the above configuration, the molten iron ore flowing through the discharge passage or the electrically conductive refractory material forming the flow passage is heated by the discharge passage heating portion, whereby the viscosity of the molten iron ore changes. This changes the fluidity of the molten iron ore, and can adjust the flow rate to a desired value.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include: a slag discharge passage that penetrates a side wall of the furnace main body; and a slag discharge path heating unit that is provided in the slag discharge path and changes viscosity by heating slag flowing through the slag discharge path or a refractory material having conductivity and forming a flow path.

According to the above configuration, the slag discharge passage heating portion heats the slag flowing through the slag discharge passage or the electrically conductive refractory material forming the flow passage, thereby changing the viscosity of the slag. This changes the fluidity of the slag, and the flow rate can be adjusted to a desired value.

In the above electrolytic smelting furnace, the furnace main body may further include an input portion that introduces the iron ore input from outside into the furnace main body, and the furnace bottom may change in height position toward a lower side as going from the input portion toward the discharge recess in a horizontal direction.

According to the above configuration, the height position of the hearth is changed downward from the input portion toward the discharge recess. This allows the molten iron ore and the reduced molten iron to naturally flow toward the discharge recess. As a result, the molten iron can be taken out more easily.

In the above-described electrolytic smelting furnace, the discharge passage may be provided in a bottom surface of the discharge recess, and the furnace main body may further include a stirring gas supply unit that supplies a gas from the bottom surface toward an upper direction of the molten iron ore.

According to the above configuration, the molten iron ore and the reduced molten iron in the discharge recess can be stirred by the stirring gas supply unit. This can further homogenize the molten iron ore and the molten iron.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include an auxiliary heating unit that is provided above or below the furnace main body and that keeps the temperature of the molten iron ore.

According to the above configuration, the molten iron ore in the furnace main body can be maintained in a molten state without being solidified by providing the auxiliary heating portion.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include: a separation distance detecting unit that detects a separation distance between the upper electrode and an upper surface of the molten iron ore; and an electrode moving unit that moves the upper electrode in a vertical direction so that the separation distance becomes a predetermined constant value.

Here, in order to stably perform electrolytic smelting, it is necessary to keep the voltage applied between the upper electrode and the upper surface of the molten iron ore as constant as possible. On the other hand, as the electrolytic smelting proceeds, the amount of the reduced molten iron increases, and the upper surface of the molten iron ore moves upward. In addition, the voltage between the upper electrode and the upper surface of the molten iron ore depends on the separation distance between the two. According to the above configuration, the upper electrode can be moved by the electrode moving unit so that the separation distance between the upper electrode and the upper surface of the molten iron ore is constant. This makes it possible to keep the voltage applied between the upper electrode and the molten iron ore constant. As a result, electrolytic smelting can be performed more stably.

The electrolytic smelting furnace may further include: a chamber having a space formed therein; and a vacuum pump for making the space in a vacuum state, wherein a through hole penetrating the upper electrode in the vertical direction and communicating with the space is formed in the upper electrode.

According to the above configuration, the slag can be sucked into the vacuum chamber through the through hole formed in the upper electrode. This makes it possible to more easily separate the slag and the molten iron.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include a settling gas supply unit configured to supply a gas from above to between the upper electrodes, thereby settling the iron ore floating between the upper electrodes.

Here, it is known that iron ore gradually becomes fine as it is melted and floats near the liquid surface when electrolytic smelting is performed. According to the above configuration, the iron ore floating between the upper electrodes can be settled by the settling gas supply unit. This can further homogenize the molten iron ore.

In the above electrolytic smelting furnace, the electrolytic smelting furnace may further include a settling mechanism portion that is provided between the upper electrodes and moves forward and backward into the furnace main body, thereby settling the iron ores floating between the upper electrodes.

Here, it is known that iron ore gradually becomes fine as it is melted and floats near the liquid surface when electrolytic smelting is performed. According to the above configuration, the iron ore floating between the upper electrodes can be settled by the settling mechanism. This can further homogenize the molten iron ore.

In the above electrolytic smelting furnace, at least one of the melting electrodes may be formed with a peripheral edge input portion for introducing the iron ore into a peripheral edge portion of the furnace main body, and the electrolytic smelting furnace may further include a settling mechanism portion that is provided between the upper electrodes and sinks the iron ore floating between the upper electrodes by moving forward and backward in the furnace main body, and a peripheral edge heating portion that is provided separately from the bottom electrode and the upper electrode and heats and melts the iron ore introduced from the peripheral edge input portion.

Here, in the peripheral portion inside the furnace main body, since heat is diffused to the outside through the wall surface of the furnace main body, melting of the iron ore may be difficult as compared with other regions. According to the above configuration, the iron ore can be supplied to the peripheral portion in the furnace main body through the peripheral edge charging portion. The iron ore can be heated and melted by the peripheral edge heating portion. This can further promote homogenization of the molten iron ore in the furnace main body.

An electrolytic smelting furnace according to an aspect of the present invention includes: a furnace main body into which iron ore is introduced; a furnace bottom electrode provided at a furnace bottom in the furnace main body; and a plurality of upper electrodes provided above the bottom electrode in the furnace main body, the furnace main body including: a discharge recess that is recessed further downward from the furnace bottom; a discharge passage that communicates the discharge recess with the outside; and an opening/closing unit that opens and closes the discharge path.

According to the above configuration, the molten iron produced by the electrolytic smelting can be easily taken out of the furnace main body through the discharge recess and the discharge passage. In particular, since the opening/closing portion is provided in the discharge passage, the molten iron can be more easily taken out only by starting the opening/closing portion.

Effects of the invention

According to the present invention, it is possible to provide an electrolytic smelting furnace which can be smoothly started up.

Drawings

FIG. 1 is a sectional view showing the structure of an electrolytic smelting furnace according to a first embodiment of the present invention.

FIG. 2 is a plan view showing the structure of an electrolytic smelting furnace according to the first embodiment of the present invention.

Fig. 3 is a sectional view showing the structure of a plasma torch according to a first embodiment of the present invention, and shows a state before melting iron ore.

Fig. 4 is a cross-sectional view showing the structure of the plasma torch according to the first embodiment of the present invention, and shows a state where iron ore starts to melt.

Fig. 5 is an enlarged cross-sectional view of a melting electrode according to a second embodiment of the present invention, and shows a state before melting iron ore.

Fig. 6 is an enlarged cross-sectional view of a melting electrode according to a second embodiment of the present invention, and shows a state where iron ore starts to be melted.

Fig. 7 is an enlarged cross-sectional view of a melting electrode according to a third embodiment of the present invention.

Fig. 8 is an enlarged cross-sectional view of a melting electrode according to a fourth embodiment of the present invention.

Fig. 9 is a sectional view showing the structure of a furnace main body according to a fifth embodiment of the present invention.

FIG. 10 is an explanatory view showing a configuration and an electric power system of an electrolytic smelting furnace according to a sixth embodiment of the present invention.

FIG. 11 is a sectional view showing the structure of an electrolytic smelting furnace in accordance with the seventh embodiment of the present invention.

FIG. 12 is a cross-sectional view showing a modification of the electrolytic smelting furnace in the seventh embodiment of the present invention.

FIG. 13 is a sectional view showing the structure of an electrolytic smelting furnace in an eighth embodiment of the present invention.

Fig. 14 is a sectional view showing the structure of a discharge path heating unit and a slag discharge path heating unit according to an eighth embodiment of the present invention.

FIG. 15 is an enlarged sectional view of a principal part showing the structure of an electrolytic smelting furnace in a ninth embodiment of the present invention.

Fig. 16 is an enlarged sectional view of a main part showing a structure of a melting electrode according to a tenth embodiment of the present invention.

Fig. 17 is a main-part enlarged cross-sectional view showing a modification of the melting electrode according to the tenth embodiment of the present invention.

FIG. 18 is a sectional view showing the structure of an electrolytic smelting furnace in an eleventh embodiment of the present invention.

FIG. 19 is an explanatory view showing a configuration and an electric power system of an electrolytic smelting furnace according to a twelfth embodiment of the present invention.

FIG. 20 is an explanatory view showing a modification of the electrolytic smelting furnace according to the twelfth embodiment of the present invention.

Fig. 21 is a plan view showing an example of arrangement of a conventional upper electrode.

Detailed Description

[ first embodiment ]

A first embodiment of the present invention will be described with reference to fig. 1 to 4. In the present embodiment, the electrolytic smelting furnace 100 is a device for melting iron ore and refining the molten iron ore by an electrolytic reaction. The ore to be refined is not limited to iron ore, and any mineral resource can be applied to the electrolytic smelting furnace 100 as long as it can be refined by the electrolytic reaction. In addition, scrap iron may be used as an object of smelting instead of iron ore.

As shown in fig. 1, the electrolytic smelting furnace 100 has a furnace main body 10, a hearth electrode 11, an upper electrode 12, a collector electrode 13, and a casing 14.

The furnace main body 10 is a container having a bottom 10B expanding in a horizontal plane. Iron ore is introduced into the furnace main body 10. The iron ore is melted and heated in the furnace main body 10 to become molten ore Wm. The temperature of the molten ore Wm is determined based on the melting point of the material itself. For example, the temperature of the molten ore Wm is 1200 to 2000 ℃. More preferably, the temperature is 1400 to 1700 ℃. Most preferably the temperature of the molten ore Wm is 1500 to 1600 ℃.

A bottom electrode 11 is provided on the bottom 10B of the furnace main body 10. For example, the hearth electrode 11 is formed in a plate shape integrally formed of a metal material containing molybdenum as a main component.

A plurality of upper electrodes 12 are disposed inside the furnace main body 10 and above the hearth electrode 11. As shown in fig. 2, the plurality of upper electrodes 12 are arranged in a grid pattern at equal intervals in the horizontal direction. For example, the upper electrode 12 is formed as a columnar electrode body integrally formed of a metal material including iron, chromium, vanadium, and tantalum.

All the upper electrodes 12 and the hearth electrodes 11 are energized to electrolyze the molten iron ore. At least one of the upper electrodes 12 has a plasma torch 20 (heating unit) built in the upper electrode 12, that is, the inside of the electrode main body, and serves as a melting electrode 12A capable of melting iron ore. In the example of fig. 2, a plurality of melting electrodes 12A are arranged in the upper electrode 12 at intervals in the horizontal direction. The arrangement of the upper electrode 12 is not limited to this, and may be appropriately changed according to design and specifications.

As shown in fig. 1 again, a collecting electrode 13 is embedded in a portion below the bottom electrode 11 in the bottom portion 10B of the furnace body 10. Collector electrode 13 is made of a conductive material, and one end thereof is electrically connected to furnace bottom electrode 11. In the example of fig. 1, an example in which two collector electrodes 13 are provided is shown, but the number of collector electrodes 13 is not limited to two.

These furnace main body 10, hearth electrode 11, upper electrode 12, and collector electrode 13 are covered with a casing 14 from the outside.

Next, the structure of the melting electrode 12A provided with the plasma torch 20 for melting iron ore will be described with reference to fig. 3 and 4. As shown in fig. 3, the melting electrode 12A has a cylindrical shape extending in the vertical direction. That is, a through hole 12S extending in the vertical direction is formed inside (on the inner peripheral side) the melting electrode 12A. A plasma torch 20 serving as a heating unit for heating and melting the iron ore introduced into the furnace main body 10 is provided in the through hole 12S. The plasma torch 20 includes a cylindrical torch main body 21 disposed on the inner peripheral surface of the through hole 12S, and a plasma torch electrode 22 inserted through the torch main body 21 on the further inner peripheral side.

The torch body 21 includes a large diameter portion 21L located on a side (i.e., an upper side) away from the hearth electrode 11, a small diameter portion 21S located coaxially with and below the large diameter portion 21L, and a connecting portion 21C connecting the large diameter portion 21L and the small diameter portion 21S in the vertical direction. The large-diameter portion 21L has an inner diameter larger than that of the small-diameter portion 21S. The inner diameter of the connecting portion 21C gradually decreases from the upper side to the lower side.

A plasma torch electrode 22 is disposed on the inner peripheral side of the large diameter portion 21L. The plasma torch electrode 22 is formed in a rod shape having an outer diameter smaller than an inner diameter of the large diameter portion 21L. Therefore, a gap is formed as the flow path F between the outer peripheral surface of the plasma torch electrode 22 and the inner peripheral surface of the large diameter portion 21L. In the flow path F, the working gas supplied from the outside flows downward from above. The working gas is usually Ar, N2, or the like, but a flammable gas (e.g., hydrogen) may also be preferably used. Then, a voltage is applied between the torch main body 21 and the plasma torch electrode 22 by a power supply. By applying a current between the torch body 21 and the plasma torch electrode 22 based on such a voltage, the working gas is ionized to form a high-temperature plasma jet J1. The plasma jet J1 is ejected from below the plasma torch 20 toward the hearth electrode 11 side.

In the electrolytic smelting furnace 100 configured as described above, first, iron ore M is charged into the furnace main body 10. Before the electrolytic smelting, the iron ore M needs to be melted. Therefore, in the present embodiment, the plasma jet J1 is formed by passing current between the torch body 21 and the plasma torch electrode 22 in a state before the melting of the iron ore M. The iron ore M starts to be heated and melted by the heat energy of the plasma jet 11.

The operation of the plasma torch 20 described above is changed in a state where the iron ore M starts to melt. Specifically, as shown in fig. 4, in this state, current is passed between the plasma torch electrode 22 and the hearth electrode 11. Thereby, a plasma jet J2 is formed between the torch main body 21 and the hearth electrode 11. The melted iron ore M starts to be entirely melted by the heat energy of the plasma jet J2, and the molten iron ore Wm is formed.

Next, the molten iron ore Wm is subjected to electrolytic smelting. Specifically, a dc voltage is applied such that the upper electrode 12 is positive and the collector electrode 13 is negative. Electrolytic reaction (reduction reaction) is performed by the voltage, and iron sesquioxide (Fe) contained in the molten ore Wm is melted ₂ O ₃ ) Is reduced. As the reduction reaction proceeds, molten iron Wf (pure iron) precipitates, and this molten iron Wf precipitates toward the hearth electrode 11 due to its own weight. By increasing the amount of precipitation of the molten iron Wf, the molten iron Wf itself functions as a cathode-side terminal in addition to the hearth electrode 11.

On the other hand, oxygen is generated on the upper electrode 12 side.

As described above, according to the above configuration, the iron ore M can be heated and melted by the plasma torch 20 of the melting electrode 12A before the electrolytic smelting. This makes it possible to easily produce the molten iron ore Wm. This enables the electrolytic smelting furnace 100 to be smoothly started to operate.

Further, since the plasma torch 20 is provided inside the melting electrode 12A, the size and the shape of the melting electrode 12A can be suppressed to be small. This can further improve the degree of freedom in the arrangement of the upper electrode 12 including the melting electrode 12A.

Further, according to the above configuration, the plasma jet J1 is formed by passing current between the torch body 21 and the plasma torch electrode 22 in a state before the melting of the iron ore M. The iron ore M can be efficiently melted by the plasma jet J1.

Further, according to the above configuration, in a state where the iron ore M starts to be melted, another plasma jet J2 is formed by passing current between the plasma torch electrode 22 and the hearth electrode 11. The plasma jet J2 can more efficiently melt and homogenize the iron ore M that has started to be melted. Even when the molten iron ore Wm is solidified due to, for example, interruption of the operation, the molten iron ore Wm can be melted again by the plasma torch 20. Thus, the electrolytic smelting operation can be immediately restarted.

The first embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ second embodiment ]

Next, a second embodiment of the present invention will be described with reference to fig. 5 and 6. The same components as those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 5, the heating section 20' in the present embodiment is different from the first embodiment. The burner 20' serving as the heating unit jets a gas (mixed gas Gh) into the furnace main body 10 through the through hole 12S formed in the melting electrode 12A. Specifically, a gas containing hydrogen or an inert gas (hydrogen as an example) is used as the mixed gas Gh. The mixed gas Gh is supplied from the hydrogen supply unit 23 provided outside the furnace main body 10 to the through-hole 12S. In the present embodiment, an ignition device 12I for igniting the air-fuel mixture is provided on the inner circumferential surface of the through hole 12S. As the inert gas, a rare gas other than hydrogen can be appropriately selected and used.

The burner 20' forms a flame Fh extending toward the hearth electrode 11 (i.e., extending downward from the through-hole 12S) by igniting the above-described mixed gas Gh in a state before the iron ore M is melted. By the flame Fh, the iron ore M starts to melt.

The operation of the above-described burner 20' is changed in a state where the iron ore M starts to melt. Specifically, as shown in fig. 6, in this state, the burner 20' extinguishes the flame Fh, and discharges only the mixed gas Gh toward the molten iron ore Wm. Thereby, the molten iron ore Wm is stirred. The flame Fh is extinguished by changing the conditions of the hydrogen mixture or changing the conditions to Ar gas. In addition, iron ore may be additionally charged through the through hole 12S in a state where the burner 20' is turned off. During the stirring, the upper electrode 12 is in contact with the liquid surface of the molten iron ore Wm or is immersed below the liquid surface.

According to the above configuration, the iron ore M can be easily and quickly heated and melted by the flame Fh of the mixed gas Gh containing hydrogen.

Further, according to the above configuration, the mixed gas Gh for melting the iron ores M is supplied to the molten iron ores Wm in a flameout state, so that the molten iron ores Wm can be stirred. This can homogenize the molten iron ore Wm. In addition, since a dedicated device for stirring is not required, the structure of the device can be simplified. This can reduce the manufacturing cost and the operating cost.

The second embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ third embodiment ]

Next, a third embodiment of the present invention will be described with reference to fig. 7. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 7, in the present embodiment, in addition to the configuration described in the first embodiment, the power supply unit (refining power supply unit 31) for applying a voltage between the hearth electrode 11 and the upper electrode 12 and the power supply unit (starting power supply unit 32) for applying a voltage between the hearth electrode 11 and the plasma torch electrode 22 are electrically independent from each other.

The refining power supply unit 31 includes a refining wire 31L for electrically connecting the hearth electrode 11 and the melting electrode 12A, and a dc power supply P1 and a switch 31S provided on the refining wire 31L. The supply state of the electric power supplied from the dc power supply P1 is switched by opening and closing the switch 31S.

The starting power supply unit 32 includes a starting wire 32L for electrically connecting the hearth electrode 11 and the plasma torch electrode 22, and a power supply P2 and a switch 32S provided on the starting wire 32L. The supply state of the electric power supplied from the power source P2 is switched by opening and closing the switch 32S.

Here, the voltage required at the start of operation (i.e., at the start of melting the iron ore) is larger than that at the time of refining. According to the above configuration, the refining power supply unit 31 and the starting power supply unit 32 are provided independently. Therefore, compared to a configuration in which the refining power supply unit 31 and the starting power supply unit 32 are not independent of each other, for example, variations in voltage generated by each power supply unit can be suppressed. This enables the electrolytic smelting furnace 100 to be operated more stably.

The third embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ fourth embodiment ]

Next, a fourth embodiment of the present invention will be described with reference to fig. 8. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 8, in the present embodiment, the upper electrode 12 is provided with a charging hole 12H for charging the iron ore before melting, in a charging electrode 12' other than the melting electrode 12A. The input hole 12H penetrates the input electrode 12' in the vertical direction. A device (not shown) such as a hopper or a screw feeder is provided above the input hole 12H. The iron ore before melting is introduced into the charging hole 12H from the outside by these devices, and charged into the furnace main body 10.

The input electrode 12 'is provided with one of the plasma torch 20 and the burner 20' as the heating portions described in the above embodiments. That is, the above-mentioned inlet hole 12H also serves as a flow path for the gas used in the plasma torch 20 or the burner 20'.

According to the above configuration, the iron ore can be smoothly charged into the furnace main body 10 through the charging hole 12H. Further, since the charging holes 12H are formed in a part of the upper electrode 12, the number and density of the upper electrodes 12 can be increased as compared with a case where charging ports for charging iron ore are separately provided. As a result, the refining can be performed more stably.

The fourth embodiment of the present invention has been described above. It is to be noted that various changes and modifications can be made to the above-described configuration without departing from the technical spirit of the present invention. For example, in the fourth embodiment, an example is described in which all of the upper electrodes 12 except the melting electrode 12A are the input electrodes 12'. However, only a part of the upper electrode 12 other than the melting electrode 12A may be used as the feeding electrode 12'.

[ fifth embodiment ]

Next, a fifth embodiment of the present invention will be described with reference to fig. 9. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 9, the electrolytic smelting furnace 200 according to the present embodiment further includes a heater H as an auxiliary heating unit in addition to the respective configurations described in the first embodiment. The heater H is provided to keep the molten iron ore Wm stored in the furnace main body 10 in a molten state by maintaining the temperature of the iron ore Wm. The heater H is provided at least one of above and below the furnace main body 10. In the example of fig. 9, a configuration is shown in which the first heater H1 is provided above and the second heater H2 is provided below.

More specifically, the first heater H1 has a plate shape facing the furnace body 10 with a gap therebetween. The first heater H1 has a plurality of openings H through which the upper electrodes 12 are inserted. The second heater H2 is buried under the collector 13 in the bottom portion 10B of the furnace main body 10. The second heater H2 also has a plate shape like the first heater H1.

According to the above configuration, by providing the heater H as the auxiliary heating unit, the molten iron ore in the furnace main body 10 is not solidified, and the molten state can be maintained. Thereby, the electrolytic smelting can be performed more stably.

The fifth embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ sixth embodiment ]

Next, a sixth embodiment of the present invention will be described with reference to fig. 10. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 10, the electrolytic smelting furnace 300 according to the present embodiment further includes a separation distance detecting section 41 that detects a separation distance L between the bottom surface (electrode bottom surface 12B) of the upper electrode 12 and the upper surface (molten iron surface Sw) of the molten iron Wf, and an electrode moving section 42 that moves the upper electrode 12 in the vertical direction based on the value of the separation distance.

The separation distance detecting unit 41 measures the current and voltage flowing between the upper electrode 12 and the hearth electrode 11, and calculates the separation distance L based on the current characteristics and the voltage characteristics. As described above, the separation distance L relates to the upper surface of the molten iron Wf. In other words, the separation distance L is the thickness of the molten iron ore Wm located in the upper layer of the molten iron Wf. Here, if the separation distance L increases, the resistance increases due to the increase in the separation distance L. Therefore, when the separation distance L increases, the amount of current flowing between the upper electrode 12 and the hearth electrode 11 decreases. That is, by measuring the amount of current at a certain voltage value, a change in the separation distance L can be detected.

When the change in the separation distance L is detected by the separation distance detecting unit 41, the electrode moving unit 42 moves the upper electrode 12 in the vertical direction so as to adjust the separation distance L to a predetermined value. As the electrode moving unit 42, various actuators, motors, and the like are preferably used.

Here, in order to stably perform the electrolytic smelting, it is necessary to keep the voltage applied between the upper electrode 12 and the molten iron surface Sw constant as much as possible. On the other hand, as the electrolytic smelting proceeds, the amount of the reduced molten iron Wf increases, and the upper surface (molten iron surface Sw) of the molten iron Wf moves upward. In addition, the voltage between the upper electrode 12 and the molten iron surface Sw depends on the separation distance therebetween. According to the above configuration, the upper electrode 12 can be moved by the electrode moving unit 42 so that the separation distance L between the upper electrode 12 and the molten iron surface Sw becomes a constant value. This can keep the voltage applied between the upper electrode 12 and the molten iron Wf constant. As a result, the electrolytic smelting can be performed more stably.

The sixth embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ seventh embodiment ]

Next, a seventh embodiment of the present invention will be described with reference to fig. 11. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 11, in the electrolytic smelting furnace 400 of the present embodiment, the furnace main body 10' further includes a discharge recess 10H recessed further downward from the furnace bottom (bottom portion 10B), a discharge passage 10E for communicating the discharge recess 10H with the outside, an opening/closing portion 5 for switching the communication state by opening/closing the discharge passage 10E, and an outer periphery heating device 6 for covering the inside of the discharge recess 10H from the outside.

The discharge recess 10H has a rectangular cross-sectional shape recessed downward from the bottom portion 10B. The discharge passage 10E is provided above the bottom surface of the discharge recess 10H (discharge recess bottom surface 10S). An outer periphery heating device 6 for heating the portion below the discharge passage 10E in the discharge recess 10H is provided. As the outer circumference heating means 6, specifically, an IH heater or the like is preferably used.

According to the above configuration, the molten iron Wf produced by the electrolytic smelting can be easily taken out of the furnace main body 10 through the discharge recess 10H and the discharge passage 10E. In particular, since the opening/closing portion 5 is connected to the discharge passage 10E, the molten iron Wf can be more easily taken out only by opening the opening/closing portion 5.

Further, according to the above configuration, the discharge passage 10E is provided above the bottom surface of the discharge recess 10H (the discharge recess bottom surface 10S). The portion below the discharge passage 10E is covered from the outside by the outer periphery heating device 6. Therefore, for example, a component solidified in the discharge recess 10H when the operation is interrupted can be melted immediately when the operation is resumed. This makes it possible to more smoothly operate the electrolytic smelting furnace 400.

The seventh embodiment of the present invention has been described above. It is to be noted that various changes and modifications can be made to the above-described configuration without departing from the technical spirit of the present invention. For example, instead of the configuration of the seventh embodiment, as shown in fig. 12, an exhaust passage 10E' may be formed in the bottom surface 10S of the exhaust recess. In the example shown in the figure, an agitation gas supply unit 7 is further provided, and the agitation gas supply unit 7 supplies hydrogen, ar gas, and the like for agitating the molten iron Wf from the bottom surface 10S of the discharge recess portion into the discharge recess portion 10H.

According to the above configuration, the molten iron Wf can be naturally taken out to the outside by gravity through the discharge passage 10E'. The molten iron ore Wm and the molten iron Wf in the discharge recess 10H can be stirred by the stirring gas supply portion 7. Further, the molten iron ores Wm and the molten iron Wf can be stirred by the electromagnetic stirring effect obtained by the induction heating. This can further homogenize and homogenize the molten iron ore Wm and the molten iron Wf.

[ eighth embodiment ]

Next, an eighth embodiment of the present invention will be described with reference to fig. 13 and 14. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 13, the electrolytic smelting furnace 500 of the present embodiment is provided with a slag discharge passage 10F for taking out the slag Ws generated in the main body 10 as the furnace electrolytic smelting proceeds, a slag discharge passage heating portion Hs for heating the slag Ws flowing through the slag discharge passage 10F, and a discharge passage heating portion Hf for heating the molten iron ore Wm flowing through the discharge passage 10E, in addition to the configuration described in the seventh embodiment.

The slag discharge passage 10F penetrates the side wall of the furnace main body 10. The slag discharge passage 10F is formed at a position separated upward from the hearth electrode 11. The slag discharge path 10F is provided with an opening/closing unit 5' for changing the open/closed state of the slag discharge path 10F. The slag discharge path heating section Hs heats the slag Ws flowing through the slag discharge path 10F to change the viscosity (reduce the viscosity). This enables adjustment of the discharge flow rate of the slag Ws.

The discharge passage 10E is provided with a discharge passage heating portion Hf, similarly to the slag discharge passage heating portion Hs. The discharge path heating portion Hf changes (reduces) the viscosity by heating the molten iron ore Wm (molten iron Wf) flowing through the discharge path 10E. This enables adjustment of the discharge flow rate of the molten iron ore Wm (molten iron Wf).

As specific examples of these discharge path heating section Hf and slag discharge path heating section Hs, the configuration shown in fig. 14 is preferably used. As shown in the drawing, the high-frequency coils 51 as the drain heating portion Hf and the slag drain heating portion Hs are disposed so as to cover the outer periphery of the drain 10E (or the slag drain 10F). Further, the stopper 50 may be provided so as to move forward and backward inside and outside the discharge passage 10E (or the slag discharge passage 10F). The open/close state of the discharge passage 10E (or the slag discharge passage 10F) can be changed by moving the plug 50 forward and backward.

According to the above configuration, the discharge path heating portion Hf heats the molten iron ore Wm that flows through the discharge path 10E, and the viscosity of the molten iron ore Wm changes. This changes the fluidity of the molten iron ore Wm, and the flow rate can be adjusted to a desired value.

Further, according to the above configuration, the slag discharge path heating section Hs heats the slag Ws flowing through the slag discharge path 10F, and the viscosity of the slag Ws changes. This changes the fluidity of the slag Ws, and the flow rate can be adjusted to a desired value.

The eighth embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention.

[ ninth embodiment ]

Next, a ninth embodiment of the present invention will be described with reference to fig. 15. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 15, the electrolytic smelting furnace 600 according to the present embodiment further includes a chamber 60 in which a space V communicating with the through hole 12S of the upper electrode 12 is formed, and a vacuum pump 61 that vacuums air from the space V in the chamber 60. The space V communicates with an upper end of the through hole 12S. When the space V is evacuated, the slag Ws passes through the through-hole 12S and is sucked into the space V.

According to the above configuration, the slag Ws can be sucked into the vacuum chamber 60 (space V) through the through hole 12S formed in the upper electrode 12. This makes it possible to more easily separate the slag Ws and the molten iron Wf.

The ninth embodiment of the present invention has been described above. It is to be noted that various changes and modifications can be made to the above-described configuration without departing from the technical spirit of the present invention.

[ tenth embodiment ]

Next, a tenth embodiment of the present invention will be described with reference to fig. 16. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 16, the electrolytic smelting furnace 700 of the present embodiment is further provided with a settled gas supply unit 70. The settling gas supply unit 70 supplies gas from above between the upper electrodes 12, thereby settling the iron ores M floating between the upper electrodes 12. The settling gas supplier 70 may be inserted into the molten iron ore Wm to supply gas into the molten iron ore Wm.

Here, it is known that the iron ore M is gradually made finer along with melting during the electrolytic smelting, and the finely made iron ore M floats in the vicinity of the liquid surface of the molten iron ore Wm. According to the above configuration, the iron ores M floating between the upper electrodes 12 can be settled by the settling gas supply unit 70. Further, by supplying a gas into the molten iron ore, floating iron ore can be entrained into the molten iron ore. This can further homogenize the molten iron ore Wm.

The tenth embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention. For example, as shown in fig. 17, a structure including a settling mechanism 70' may be adopted instead of the settling gas supply unit 70. The precipitation mechanism 70' moves forward and backward in the vertical direction between the upper electrodes 12. When the floating iron ore M is generated as described above, the settling mechanism 70' can be moved downward, and the iron ore M can be settled into the molten iron ore Wm. This can further homogenize the molten iron ore.

[ eleventh embodiment ]

Next, an eleventh embodiment of the present invention will be described with reference to fig. 18. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 18, the electrolytic smelting furnace 800 of the present embodiment is different from the above-described embodiments in the structure of the furnace main body 10'. The furnace bottom B of the furnace main body 10' is configured to change in height in a downward step as it goes from the input portion 80 toward the discharge recess 10H in the horizontal direction. That is, the height position of the furnace bottom B gradually decreases from the center portion to the peripheral portion of the furnace main body 10'. The central portion is a region including a portion through which a central axis O extending in the vertical direction passes, as shown in fig. 18.

More specifically, the hearth B includes a first hearth B1, a second hearth B2, and a third hearth B3 arranged in this order from the side away from the discharge recess 10H toward the discharge recess 10H. The second hearth B2 is located below the first hearth B1. The third hearth B3 is located below the second hearth B2. In the present embodiment, for the sake of simplicity of explanation, an example in which the height of the furnace bottom B changes in three stages is shown, but the furnace bottom B may be divided into four or more heights.

According to the above configuration, the height position of the hearth B changes downward from the input portion 80 toward the discharge recess 10H. This allows the molten iron ore Wm and the reduced molten iron Wf to naturally flow toward the discharge recess 10H. As a result, the molten iron Wf can be taken out more easily.

The eleventh embodiment of the present invention has been described above. It is to be noted that various changes and modifications can be made to the above-described configuration without departing from the technical spirit of the present invention.

[ twelfth embodiment ]

Next, a twelfth embodiment of the present invention will be described with reference to fig. 19. The same components as those in the above embodiments are denoted by the same reference numerals, and detailed description thereof is omitted. As shown in fig. 19, in the electrolytic smelting furnace 900 according to the present embodiment, the melting electrode 12A, which is at least one of the melting electrodes 12A and is disposed in a portion along the side wall of the furnace main body 10, is formed with a peripheral edge input portion 80' that penetrates the melting electrode 12A in the vertical direction. The electrolytic smelting furnace 900 further includes a peripheral edge heating section 90 that heats and melts the iron ore M introduced from the peripheral edge input section 80'.

The peripheral edge heating portion 90 includes a pair of

electrode terminals

91 and 91 provided separately from the furnace bottom electrode 11 and the upper electrode 12. The

electrode terminals

91 and 91 are immersed in the molten iron ore Wm (or molten iron Wf). A voltage is applied to the

electrode terminals

91 and 91 by a power supply P. Thereby, a joule heating portion is formed between the

electrode terminals

91 and 91. As a result, when new iron ore is charged into the molten iron ore Wm, the iron ore is heated and melted by the joule heating portion. The stirring gas supply unit 70B is preferably provided in the vicinity of the

electrode terminals

91 and 91. The stirring gas supply portion 70B supplies a gas to the molten iron ore Wm that is melted by the peripheral edge heating portion 90, and stirs the molten iron ore Wm.

Here, in the peripheral edge portion inside the furnace main body 10, since heat is diffused to the outside through the wall surface of the furnace main body 10, the melting of the iron ore may be difficult to progress as compared with other regions. According to the above configuration, the iron ore can be supplied to the peripheral portion in the furnace main body 10 through the peripheral edge charging portion 80', and the iron ore can be heated and melted by the peripheral edge heating portion 90. This can further promote the temperature equalization and homogenization of the molten iron ore Wm in the furnace main body 10.

The twelfth embodiment of the present invention has been described above. It is to be noted that various changes and modifications may be made to the above-described configuration without departing from the scope of the technical spirit of the present invention. For example, as the peripheral edge heating section 90', as shown in fig. 20, an upper electrode 12 and a side electrode 92 buried in a side wall of the furnace main body 10 may be provided. By forming the joule heating portion as described above between the upper electrode 12 and the side electrode 92, the iron ore M newly charged can be melted.

Industrial applicability of the invention

In the electrolytic smelting furnace according to the aspect of the present invention, the start of operation can be smoothly performed.

Description of reference numerals:

100. 200, 300, 400, 500, 600, 700, 800, 900: an electrolytic smelting furnace;

10. 10': a furnace main body;

10B: a bottom;

10E: a discharge path;

10F: a slag discharge path;

10H,10H': a discharge recess;

10S: a bottom surface of the discharge recess;

11: a furnace bottom electrode;

12: an upper electrode;

12A: an electrode for melting;

12A': a feeding electrode;

12B: an electrode bottom surface;

12S: a through hole;

12H: a feeding hole part;

12I: an ignition device;

14: a housing;

20: a plasma torch;

20': a burner;

21: a torch body;

21L: a large diameter part;

21S: a small diameter part;

21C: a connecting portion;

22: a plasma torch electrode;

23: a hydrogen supply unit;

31: a refining power supply unit;

31L: refining the electric wire;

31S, 32S: a switch;

32: a power supply unit for starting;

32L: starting the power wire;

41: a separation distance detection unit;

42: an electrode moving part;

5. 5': an opening/closing section;

50: a plug;

51: a high-frequency coil;

6: a peripheral heating device;

60: a chamber;

61: a vacuum pump;

7. 70, 70', 70B: a stirring gas supply unit;

80: a feeding section;

80': a peripheral input section;

90. 90': a peripheral heating section;

91: an electrode terminal;

92: a side electrode;

b: the furnace bottom;

b1: a first hearth;

b2: a second hearth;

b3: a third furnace bottom;

f: a flow path;

fh: a flame;

gh: mixing the gas;

h: an opening part;

h: a heater;

h1: a first heater;

h2: a second heater;

hf: a discharge path heating section;

hs: a slag discharge path heating section;

j1, J2: a plasma stream;

m: iron ore;

p1: an alternating current power supply;

p2: a direct current power supply;

sw: the molten iron level;

v: a space;

and (Wm): melting iron ore;

wf: melting iron;

ws: and (3) slag.

Claims

1. An electrolytic smelting furnace, wherein,

the electrolytic smelting furnace is provided with:

a furnace main body into which iron ore is introduced;

a furnace bottom electrode provided at a furnace bottom in the furnace main body;

a plurality of upper electrodes provided above the furnace bottom electrode in the furnace main body, and having an electrode main body for electrowinning molten iron ore; and

a settling gas supply unit configured to supply a gas from above to between the upper electrodes to settle the iron ores floating between the upper electrodes,

at least one of the upper electrodes is a melting electrode having a heating portion inside the electrode body, and the heating portion heats and melts the iron ore to obtain the molten iron ore.

2. An electrolytic smelting furnace, wherein,

the electrolytic smelting furnace is provided with:

a furnace main body into which iron ore is introduced;

a settling mechanism part which is provided between the upper electrodes and settles the iron ore floating between the upper electrodes by moving forward and backward in the furnace main body,

3. The electrolytic smelting furnace according to claim 1 or 2,

the heating part has: a cylindrical torch body disposed on an inner peripheral surface of a through hole formed in the electrode body; and a plasma torch electrode inserted through an inner peripheral side of the torch body,

in a state before the iron ore is melted, the iron ore is melted by a plasma jet formed by passing electricity between the torch body and the plasma torch electrode.

4. The electrolytic smelting furnace according to claim 3,

the heating unit heats the molten iron ore by a plasma jet formed by applying electricity between the plasma torch electrode and the hearth electrode in a state where the iron ore starts to be molten.

5. The electrolytic smelting furnace according to claim 4,

the electrolytic smelting furnace further includes:

a refining power supply unit for applying a voltage between the hearth electrode and the upper electrode; and

and a starting power supply unit which is provided independently of the refining power supply unit and applies a voltage between the hearth electrode and the plasma torch electrode.

6. The electrolytic smelting furnace according to claim 1 or 2,

the heating section melts the iron ore by a flame formed of a mixed gas containing hydrogen in a state before the iron ore is melted.

7. The electrolytic smelting furnace according to claim 6,

the heating section extinguishes the hydrogen-containing mixed gas and supplies the oxygen-containing mixed gas to the molten iron ore in a state where the iron ore starts to be molten, thereby stirring the molten iron ore.

8. The electrolytic smelting furnace according to claim 1 or 2,

at least one of the upper electrodes is formed with a feed hole portion that penetrates the upper electrode in the vertical direction to introduce the iron ore into the furnace main body.

9. The electrolytic smelting furnace according to claim 1 or 2,

the furnace main body further includes:

a discharge recess that is recessed further downward from the furnace bottom;

a discharge passage that communicates the discharge recess with the outside; and

and an opening/closing unit that opens and closes the discharge path.

10. The electrowinning furnace in accordance with claim 9,

the discharge passage is provided above the bottom surface of the discharge recess, and an outer periphery heating device that covers the lower portion of the discharge recess from the outside is provided in the lower portion of the discharge passage.

11. The electrowinning furnace in accordance with claim 9,

the electrolytic smelting furnace further includes a discharge path heating unit that is provided in the discharge path and heats the molten iron ore or the electrically conductive refractory material forming the flow path, which flows through the discharge path, to change viscosity.

12. The electrolytic smelting furnace according to claim 9,

the electrolytic smelting furnace is further provided with:

a slag discharge passage that penetrates a side wall of the furnace main body; and

and a slag discharge path heating unit that is provided in the slag discharge path and changes viscosity by heating slag flowing through the slag discharge path or a refractory that has conductivity and forms a flow path.

13. The electrowinning furnace in accordance with claim 9,

the furnace main body further includes a charging portion that introduces the iron ore charged from outside into the furnace main body,

the furnace bottom changes in height downward as it goes from the input portion toward the discharge recess in the horizontal direction.

14. The electrolytic smelting furnace according to claim 9,

the discharge passage is provided on the bottom surface of the discharge recess,

the furnace main body further includes a stirring gas supply unit that supplies a gas from the bottom surface toward an upper direction of the molten iron ore.

15. The electrolytic smelting furnace according to claim 1 or 2,

the electrolytic smelting furnace is further provided with an auxiliary heating part which is arranged on at least one of the upper part and the lower part of the furnace main body and is used for preserving heat of the molten iron ore.

16. The electrolytic smelting furnace according to claim 1 or 2,

the electrolytic smelting furnace further includes:

a separation distance detecting unit that detects a separation distance between the upper electrode and an upper surface of the molten iron ore; and

and an electrode moving unit that moves the upper electrode in a vertical direction so that the separation distance is a predetermined constant value.

17. The electrowinning furnace in accordance with claim 1 or 2,

the electrolytic smelting furnace is further provided with:

a chamber having a space formed therein; and

a vacuum pump for making the space in a vacuum state,

the upper electrode is formed with a through hole penetrating the upper electrode in a vertical direction and communicating with the space.

18. An electrolytic smelting furnace, wherein,

the electrolytic smelting furnace is provided with:

a furnace main body into which iron ore is introduced;

a plurality of upper electrodes disposed above the furnace bottom electrode in the furnace main body; and

the furnace main body is provided with:

a discharge recess which is recessed further downward from the furnace bottom;

a discharge passage for communicating the discharge recess with the outside; and

and an opening/closing unit that opens and closes the discharge path.

19. An electrolytic smelting furnace, in which,

the electrolytic smelting furnace is provided with:

a furnace main body into which iron ore is introduced;

the furnace main body is provided with:

a discharge recess that is recessed further downward from the furnace bottom;

an opening/closing unit that opens and closes the discharge path.