WO2005021809A1

WO2005021809A1 - Method and apparatus for producing metal

Info

Publication number: WO2005021809A1
Application number: PCT/JP2004/010024
Authority: WO
Inventors: Tadashi Ogasawara; Makoto Yamaguchi; Masahiko Hori; Toru Uenishi
Original assignee: Sumitomo Titanium Corporation
Priority date: 2003-08-28
Filing date: 2004-07-14
Publication date: 2005-03-10
Also published as: EP1666615A1; JP2005068539A; JP4193984B2; US20060219053A1

Abstract

A method for producing a metal by the direct reduction of an oxide wherein a metal oxide is reduced with Ca, which comprises holding a molten salt containing CaCl2 as a main component in a reduction chamber (1), inserting a metal oxide into the molten salt in the reduction chamber (1), to thereby form a metal through the reduction of the metal oxide by the Ca in the molten salt, separating the metal formed in the molten salt from the molten salt by means of a separating apparatus (2), introducing the molten salt separated from the metal into a chlorination chamber (7), subjecting the molten salt to a chlorination treatment with a chlorine gas, to remove the by-produced CaO form the molten salt, introducing the molten salt after the chlorination into an electrolysis chamber (8) to electrolyze the molten salt and form Ca and chlorine from CaCl2, transporting the formed Ca or a molten salt containing said Ca from the electrolysis chamber (8) to the reduction chamber (1) and using the chlorine formed in the electrolysis chamber (8) in the chlorination chamber (7); and an apparatus for practicing the method . The method employs a direct reduction process as described above, and also achieves high productivity, and further is free from the contamination of the resultant metal with carbon, which is due to CaO, and from the generation of CO2 in the production process.

Description

Specification

Metal manufacturing method and apparatus

Technical field

TECHNICAL FIELD [0001] The present invention relates to a metal production method by an oxide direct reduction method for producing a metal such as titanium by reducing a metal oxide with Ca, and a metal production apparatus used for the method.

^ Scenic technology

[0002] The crawl method is generally used as an industrial production method of titanium metal. In this Kroll method, metallic titanium is produced through a reduction step and a vacuum separation step. In the reduction step, titanium tetrachloride (TiCl 4) is reduced by Mg in the reaction vessel, and sponge-like metallic titanium

Four

Is manufactured. In the vacuum separation process, unreacted Mg and by-product magnesium chloride (MgCl) are removed from the sponge-like titanium metal in the reaction vessel, and the product titanium is produced.

2

Built.

[0003] In the production of titanium metal by the Kroll method, a high-purity product can be produced, but the production cost is increased and the product price is increased. For this reason, there is a limitation that high-quality but high-priced metallic titanium can be produced by the crawl method.

[0004] However, there is a demand for the production of inexpensive metallic titanium, even though its purity is somewhat low, as a structural material. In order to respond to such demands, the development of a method for continuously producing low-purity metallic titanium at a low cost has been planned, and as one of the measures, an oxide that reduces titanium oxide with Ca The direct reduction method is being studied.

FIG. 1 is a diagram illustrating a known oxide direct reduction method. A typical known direct oxide reduction method is the Olson method described in US Pat. No. 2,845,386. In this method, as shown in Fig. 1, Ti powder is added to molten CaCl salt.

22 Add powder and reduce TiO with Ca to produce Ti. At the same time, in the molten salt of CaCl

twenty two

Electrolysis of CaO using iron cathode and graphite anode.

[0006] In the Olson method, CaO is by-produced on the surface of the TiO powder due to the reaction.

2

However, the by-produced CaO has the property of dissolving in CaCl, The generated Ca〇 dissolves in CaCl, and the reaction between Ti〇 and Ca continues on the surface of the Ti〇 powder

2 2 2

Progress. Furthermore, when the molten salt of CaCl containing Ca〇 is electrolyzed,

2

As shown in the reactions of equations (1) and (3), Ca〇 is removed from CaCl 2.

2

[0007] That is, according to Olson's method, Ca〇 by-produced on the surface of Ti〇 powder

Dissolved in 2 and further dissolved Ca〇 was sequentially removed from CaCl by electrolysis and accumulated.

2

Therefore, the reaction that generates Ti force Ti will continue.

2

[0008] 2CaO + C → 2Ca + C〇 (anode surface) · · · (1)

5Ca + 2CO → CaC + 4Ca〇 (near the anode)

twenty two

… (2)

2Ti + CaC → 2TiC + Ca (force sword). · · (3)

2

[0009] As described above, Olson's method does not accumulate by-product CaO,

2 Although it can be produced continuously, on the other hand, as shown in the above chemical formula (2), CaC is produced in the molten salt with the electrolysis of Ca 2 O. And the generated CaC is

twenty two

However, as shown in the above chemical formula (3), TiC is mixed into Ti, thereby deteriorating the quality of Ti.

[0010] In other words, Olson's method is based on the reaction of CaC generated in the molten salt of CaCl with the electrolysis of the force Ca〇, which is capable of continuous generation of Ti and is efficient.

twenty two

Contamination occurs. The deterioration of product quality due to such carbon (C) contamination is a fatal problem in the production of metallic titanium, and the direct oxide reduction method has not yet been put to practical use.

Disclosure of the invention

The present invention employs an oxide direct reduction method in which a metal oxide is reduced with Ca, but has a high productivity and does not cause quality deterioration such as carbon contamination. And a metal manufacturing apparatus.

[0012] In order to achieve the above object, the metal production method of the present invention comprises:

2

A metal oxide is introduced into the molten salt contained therein, and the metal oxide is reduced by Ca in the molten salt to form a metal; and a metal formed in the molten salt is separated from the molten salt. Process, and the molten salt after the metal is separated is subjected to a chlorination treatment with chlorine gas. The salinization process of salinizing CaO and the electrolysis of part or all of the molten salt after the salification treatment to produce CaCl force Ca and chlorine, containing the produced Ca or Ca

2

And sending the molten salt to the reduction step.

[0013] Further, the metal manufacturing apparatus of the present invention holds a molten salt containing CaCl as a main component and containing Ca.

2

A reduction chamber for reducing the metal oxide supplied to the molten salt with Ca in the molten salt to generate a metal, a means for separating the metal generated in the molten salt from the molten salt, and a method for separating the metal. The molten salt that has been removed is retained, the molten salt is subjected to salting treatment with chlorine gas, and a salting room for salifying by-product Ca in the molten salt is provided. An electrolysis chamber that holds part or all of the molten salt and electrolyzes the molten salt to generate CaCl force Ca and chlorine;

2

Means for transferring generated Ca or a molten salt containing the Ca from the chamber to the reduction chamber.

According to the metal production method of the present invention, for example, in the case of producing metal titanium, the target titanium is produced based on the reaction represented by the following chemical formulas (4)-(6).

Ti〇 + 2Ca

2

→ Ti + 2CaO (reduction process) · · · (4)

2CaO + 2Cl → 2CaCl +0 (chlorination step) · · · (5)

2 2 2

CaCl → Ca + Cl (electrolysis process)

twenty two

… (6)

First, in the reduction step, the titanium oxide to be charged is reduced by Ca in the molten salt, whereby titanium metal is continuously produced, and CaO is by-produced. Therefore, the molten salt after reduction becomes CaCl containing CaO by-produced in addition to titanium metal.

2

Next, in the separation step, the metallic titanium generated in the molten salt is separated from the molten salt.

Further, in the salting process, CaCl is generated from CaO by-produced in the reduction reaction by subjecting the molten salt after separating the metallic titanium to a chlorination treatment with chlorine gas. As a result,

2

The molten salt after the treatment contains substantially no CaCl and substantially only CaCl.

2

[0018] The molten salt that has been subjected to the salinization treatment and has substantially CaCl power is entirely or partially subjected to the electrolysis step.

2

The Ca is generated in the molten salt by the electrolytic treatment. And after the electrolysis process, again Molten salt containing CaCl as the main component and containing Ca is recycled to the reduction process

2

This enables continuous production of titanium metal.

[0019] The present invention includes first and second characteristic configurations. The first configuration is to perform electrolysis outside the region of the reduction reaction. The second configuration is to salt CaO in the molten salt before the electrolysis. By combining these first and second configurations, it is possible to prevent the accumulation of CaO in the reduction step and to reduce the amount of CaC due to the electrolysis of Ca〇.

2 Prevents generation and eliminates carbon contamination of generated metal. That is, the reduction reaction can be continued while preventing product contamination.

[0020] Further, the present invention is advantageous in that chlorine gas is generated at the anode in electrolysis and oxygen gas is not generated. Normally, the force of using graphite as an anode material for electrolysis As shown by the Olson method in FIG. 1, when oxygen gas is generated at the anode, carbon dioxide gas is generated as a result.

In the electrolysis shown in FIG. 1, Ca generated on the cathode side has a strong reducing power, and thus reduces metal oxides. However, as shown in the chemical formulas (2) and (3), when gaseous carbonate is present in the molten salt, CaC is generated, and this CaC mixes the metal carbide with the generated metal.

twenty two

By doing so, the quality of the produced metal is reduced.

[0022] On the other hand, in the electrolysis according to the present invention, no oxygen gas is generated at the graphite anode, and as a result, no carbon dioxide gas is generated. Moreover, since the graphite anode is not consumed, stable electrolysis conditions can be ensured.

In the production method of the present invention, it is necessary to control the temperature of the molten salt to be equal to or higher than the melting point of CaCl 2 (780 ° C.) in the reduction step, the salification step, and the electrolysis step in which the molten salt circulates. By the way

2

The melting point of Ca is 848 ° C.If Ca is melted into molten salt of CaCl,

2

Can also be dissolved. The exact solubility depends on the dissolution temperature. The dissolution of Ca can be up to about 1.5% by weight in CaCl, and the dissolution of Ca〇 is 8.0% in CaCl.

twenty two

% Is possible.

[0024] In the reduction step, powdery, granular or massive titanium oxide is charged into the molten salt. The metal titanium separated from the molten salt after reduction is likewise powdery, granular or massive and wet with the molten salt. Considering the reduction efficiency, powdered titanium oxide It is desirable to use

[0025] In the separation step, it is effective to separate metal titanium by a physical method such as sedimentation separation or compaction. If the titanium metal is solidified to some extent by sedimentation separation, compression and compaction, and the like, and then taken out, the ingot can be made into an ingot by a usual melting method such as a plasma melting method after the separation.

[0026] In the dissolving step, either a bottomless crucible or a bottomed crucible may be used as the melting crucible. When a bottomless crucible is used, a continuous structure becomes possible.

[0027] If the particle size of the titanium oxide to be charged is small, the particle size of the produced metal titanium is also small, so that sedimentation and separation in the reduction step may be inefficient. In such a case, for example, the reduction step is performed in a bottomed vessel, and the molten salt in which the generated metallic titanium is suspended at a high concentration is removed from the bottom of the vessel by stationary separation, and then the molten salt is compressed and compacted. It is efficient to adopt a method of separating the titanium produced by force. Further, the remaining molten salt is subjected to a salification treatment, whereby the utilization efficiency of the molten salt can be improved.

[0028] In the salification step, continuous and efficient salification treatment can be performed by bubbling chlorine gas into the molten salt.

[0029] If CaO remains in the titanium metal produced in the reduction step, oxygen in the CaO is contained in the titanium metal during dissolution, and the oxygen concentration in the titanium increases. In order to prevent this, CaCl that does not contain CaO after the salting treatment is injected into the relevant part of the separation step, and molten salt is added.

2

Rinsing of the metallic titanium separated from the steel with the CaCl

2

It is desirable to provide a step.

[0030] As described above, CaO can dissolve up to about 8.0% by weight in CaCl.

2

Ca〇 remaining in titanium is dissolved and dissolved in CaCl that does not contain injected Ca〇.

2

, Is removed from the metallic titanium.

[0031] In the electrolysis step, Ca is generated on the cathode side, and chlorine gas is generated on the anode side. The CaCl containing Ca extracted from the cathode in the electrolytic cell is reduced as the Ca concentration increases.

2

The reduction ability in the process can be increased.

[0032] When the Ca concentration exceeds the solubility of CaCl in the electrolytic cell, the excess Ca becomes a solid.

2

It will either suspend or separate and float. Send CaCl to the reduction step with Ca suspended

2 S power This is because, when the Ca contained in the reduction step is consumed, the suspended Ca is newly dissolved in CaCl and exerts a reducing action.

2

[0033] It is not necessary to transfer the entire CaCl from the salification process to the electrolysis process, but transfer a part of it

2

You can do it. In that case, the remaining CaCl is not subjected to the electrolytic process,

2

It may be sent directly to the power reduction step. Transfer a part of CaCl from the salting process to the electrolysis process

2

The reason is as follows.

[0034] The solubility of Ca in CaCl is low. For this reason, CaCl in which Ca is dissolved is sent to the reduction process.

twenty two

If necessary, it is necessary to cycle a large amount of CaCl to secure the specified reduction capacity.

2

There is. However, if the molten Ca is transferred from the electrolysis step to the reduction step alone, it is not necessary to cycle a large amount of CaC 1.

2

[0035] In the reduction step, if Ca from the electrolysis step is stored on the molten liquid surface, the Ca concentration in the CaCl layer can be increased by dissolving Ca from the Ca layer formed on the liquid surface into the CaCl layer. Can

twenty two

The That is, when TiO is reduced by dissolved Ca in the CaCl layer,

twenty two

The portion will be replenished in the form of dissolution into the CaCl layer from the Ca layer.

2

[0036] The manufacturing apparatus of the present invention is an apparatus that generates metal using the above-described manufacturing method of the present invention. In the production apparatus of the present invention, it is preferable that the electrolytic chamber has a configuration in which a partition wall for separating the anode side and the cathode side is provided. By providing the partition, the chlorine gas generated on the anode side does not enter the anode side, and the Ca generated on the cathode side does not return to the anode side. When providing a partition, it is better to use a porous ceramic plate (diaphragm).

On the other hand, while continuously supplying CaCl supplied from the salt process to the anode side,

2

If Ca-containing CaCl is continuously extracted from the anode, steady flow from the anode side to the cathode side

2

Flow (flow) can be formed. Then, even if a porous plate is not used for the partition wall, even if a dense plate provided with gaps and holes below the liquid level through which a small amount of molten salt can flow, for example, a metal plate with slits is used, The same Ca separation effect as when a porous plate is used can be obtained.

[0038] Chlorine gas generated on the anode side in the electrolysis chamber is used for bubbling in the salification step.

[0039] In order to reduce the size of the apparatus, the salt shaving room can be combined with the reduction chamber. Also the same For the purpose of the above, the electrolysis chamber can also be combined with the reduction chamber. Here, the uniting means that another chamber is continuously installed next to a specific chamber, and a partition partitioning between the two chambers may or may not be provided, and a case where no partition is provided will be described later. Means unity.

[0040] The cathode side of the electrolysis chamber combined with the reduction chamber can be integrated with the reduction chamber by removing a partition partitioning the two chambers. The electrolytic chamber can be formed in a ring around the cylindrical reduction chamber, and more specifically, the outer cylinder also serves as an anode and the cathode also serves as a cathode, so that the molten salt can flow therethrough. And it can be constituted by a combination with an inner cylinder having a reduction chamber on the inside.

Brief Description of Drawings

FIG. 1 is a diagram illustrating a known oxide direct reduction method.

FIG. 2 is a diagram illustrating a configuration of a titanium manufacturing facility according to the first embodiment of the present invention.

FIG. 3 is a diagram illustrating a configuration of a titanium manufacturing facility according to a second embodiment of the present invention.

FIG. 4 is a diagram illustrating a configuration of a titanium manufacturing facility according to a third embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration of a titanium manufacturing facility according to a fourth embodiment of the present invention.

FIG. 6 is a diagram illustrating a configuration of a titanium manufacturing facility according to a fifth embodiment of the present invention.

FIG. 7 is a diagram illustrating a configuration of a titanium manufacturing facility according to a sixth embodiment of the present invention.

FIG. 8 is a view for explaining a cross-sectional configuration of the titanium manufacturing facility shown in FIG. 7 in the XX view.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, first to sixth embodiments of the present invention will be described with reference to the drawings.

(First Embodiment)

FIG. 2 is a diagram illustrating a configuration of a titanium manufacturing facility according to the first embodiment of the present invention. The In the first embodiment, a reduction chamber 1 having a tower shape and a horizontal separation device 2 connected to a lower portion thereof are provided. The reduction chamber 1 contains a molten salt containing CaCl as a main component and containing Ca.

2

The powder of titanium oxide (TiO 2) as a raw material is continuously supplied.

2

[0043] As a result, in the reduction chamber 1, Ti〇 introduced into the molten salt is returned by Ca in the molten salt.

2

To produce metallic titanium (Ti) and, at the same time, by-product Ca 副. Both the generated Ti and by-product Ca O are settled and separated from the molten salt, and with a small amount of CaCl,

2

Inflow.

[0044] In the reduction chamber 1, a solution containing CaCl as a main component and Ca as well as titanium oxide as a raw material is contained.

2

The molten salt is additionally supplied from above. On the other hand, from the lower part of the reduction chamber 1, the molten salt is extracted to the side by the separation device 2. As a result, a downward flow of the molten salt is formed in the reduction chamber 1. This molten salt flow promotes the sedimentation and separation of the aforementioned generated Ti and by-product Ca〇.

[0045] In the separation device 2, the molten salt that contains a large amount of the generated Ti and by-product CaO that has flowed in is physically compressed in the cylinder using the cylindrical perforated screw 3. By this physical separation operation, the molten salt can be squeezed out of the produced Ti and the produced Ti can be compacted. The compacted porous Ti is discharged sequentially from the separation device 2 and dissolved in the dissolution device 4.

[0046] The Ti formed by compression-separating the molten salt in the separation device 2 has CaCl as a main component and no CaO.

2

Rinsing treatment can be performed with a molten salt. If Ca で remains in the generated Ti, oxygen in CaO is contained in the titanium metal at the time of dissolution and the oxygen concentration increases, so that CaO is prevented from remaining. Specifically, a molten salt that has been salified in the salification chamber 7 described later and does not contain CaO is used for rinsing, and CaO remaining in the generated Ti is dissolved in CaCl,

2

Removed from Ti.

In the melting device 4, a plasma device is used, and the generated Ti lump is melted in an insoluble atmosphere, and the molten Ti is stored in the primary water-cooled mold 5. In the primary water-cooled mold 5, the molten Ti sediments and the molten salt floats. The molten Ti separated from the molten salt is poured into a water-cooled secondary mold 6, where it is formed into a Ti ingot.

[0048] Although the Ti melted in the melting device 4 was compressed and separated from the molten salt in the separation device 2, Contains molten salts. Therefore, the molten salt can be floated and separated by storing the molten Ti in the primary water-cooled mold 5. The separated molten salt is sent to the chloride tank 7 described below.

[0049] Both the molten salt separated from the Ti produced by the separation device 2 and the molten salt floated and separated by the primary water-cooled mold 5 are sent to the chloride chamber 7. Since these molten salts contain a large amount of by-product CaO, chlorine gas is bubbled into the molten salt introduced in the salting chamber 7 to convert CaO in the molten salt. CaO contained in the molten salt is converted to CaCI

2 to form a molten salt that does not contain CaO but also has a substantial CaCI force.

2

[0050] The molten salt not containing CaO is then sent to the electrolysis chamber 8 with a force S, as described above, part of which is sent to the separation device 4 for rinsing. In the electrolytic chamber 8, the introduced molten salt is electrolyzed using a graphite anode and an iron cathode, and chlorine gas is generated on the anode side in the chamber and Ca is generated on the cathode side. As a result, molten salt containing CaCI as a main component and Ca

2

Generated.

[0051] In the salification chamber 7, CaO, which is a removal target, is salified. On the other hand, since a molten salt containing Ca is necessary in the reduction chamber 1, a molten salt containing Ca is generated in the electrolytic chamber 8 and sent to the reduction chamber 1. In this way, external replenishment of CaCI and Ca is virtually impossible.

2

It becomes unnecessary. The chlorine gas by-produced in the electrolysis chamber 8 is sent to the chlorination chamber 7 to be circulated.

[0052] In the electrolytic chamber 8, the anode side and the cathode side are separated by a porous partition wall 9. The molten salt sent from the salt chamber 7 is introduced to the anode side, and the molten salt containing Ca is extracted from the cathode side and sent to the reduction chamber 1. Thereby, a flow from the anode side to the cathode side is formed. As a result, backflow of the molten salt from the cathode side to the anode side is prevented. In addition, chlorine gas is prevented from entering the anode side cathode side.

(Second Embodiment)

FIG. 3 is a diagram illustrating a configuration of a titanium manufacturing facility according to a second embodiment of the present invention. In the second embodiment, compared to the first embodiment shown in FIG. 2, a part of the molten salt that has been subjected to the salting treatment in the chloride chamber 7 is sent to the electrolytic chamber 8, and almost all of the remaining molten salt is left. Is different from returning electrolysis to reduction chamber 1 and transferring Ca from electrolysis chamber 7 to reduction chamber 1 in a metallic state. To do. However, in the second embodiment, when Ca is transferred to the reduction chamber 1 in a metal state, a method in which Ca is dissolved in CaCl and transferred may be used in combination.

2

[0054] Therefore, in the electrolytic chamber 8, the molten salt from the salt shading chamber 7 is introduced to the anode side, and Ca generated on the liquid level on the cathode side is sent to the reduction chamber 1 alone or together with some CaCl. Return room 1

2

The transferred Ca floats on the liquid surface of the molten salt in the room and dissolves in CaCl. Because of this, salt

2

The Ca concentration in CaCl in reduction chamber 1 is maintained at a high level, despite the small amount of molten salt or Ca transferred from reduction chamber 7 to reduction chamber 1 through electrolysis chamber 8.

2

As described above, a part of the molten salt is transferred from the chloride chamber 7 to the electrolysis chamber 8 by CaCl

Considering the low solubility in 2, the cycle with a large amount of CaCl is eliminated,

2

Overall manufacturing efficiency can be improved.

(Third Embodiment)

FIG. 4 is a diagram illustrating a configuration of a titanium manufacturing facility according to a third embodiment of the present invention. The third embodiment is different from the production facility of the second embodiment shown in FIG. 3 in that the reduction chamber 1 and the salt shading chamber 7 are combined. However, other configurations are substantially the same as the manufacturing facilities of the second embodiment.

[0057] The chloride chamber 7 is formed on the side of the vertical reduction chamber 1 with a partition 10 interposed therebetween. In the reduction chamber 7, titanium oxide is added to the CaCl by a feed pipe 11 inserted into the molten CaCl salt in the chamber.

twenty two

Is inserted from above. Formed from titanium oxide by reduction with Ca in CaCl

2

The titanium thus settles down at the bottom of the reduction chamber 1, is extracted downward, and is sent to the separation device 2 below.

[0058] CaCl containing by-produced CaO flows from the reduction chamber 1 into the salt shaving chamber 7 at the lower part, and is injected from the lower part.

2

CaO is salified by being subjected to salting treatment by the chlorine gas entering. CaCl rises in the chlorination chamber 7 due to the chlorine gas flow (gas lift) rising in the chlorination chamber 7. Separation equipment

2

The CaCl separated from the titanium metal in the device 2 is also introduced into the lower part of the salt shading room 7. Meanwhile, salt

2

The oxygen gas by-produced in the gasification chamber 7 is extracted upward.

[0059] Most of the CaCl that has exited the chloride chamber 7 is returned to the reduction chamber 1 from above the chloride chamber 7. Remaining

2

CaCl is transferred to the electrolysis chamber 8. In the electrolysis chamber 8, the introduced CaCl force Ca is generated.

twenty two

The Ca generated in electrolysis chamber 8 is reduced alone or with a small amount of Ca-rich CaCl

2 Transferred to room 1. In addition, the by-produced chlorine gas is sent to the chlorination chamber 7 for circulating use.

[0060] The Ca introduced into the reduction chamber 1 forms a layer on CaCl in the reduction chamber 1. The throw mentioned earlier

2

The inlet pipe 11 is for introducing titanium oxide into CaCl through the Ca layer on CaCl.

twenty two

Confuse.

[0061] In a titanium manufacturing facility in which the Shii-Dai room 7 is combined with the reduction room 1, CaCl is exchanged between the two rooms.

2 becomes easier. It is also possible to transfer all of the CaCl leaving the chloride chamber 7 to the electrolytic chamber 8.

2

Confuse.

(Fourth Embodiment)

FIG. 5 is a diagram illustrating a configuration of a titanium manufacturing facility according to a fourth embodiment of the present invention. In the fourth embodiment, as compared with the manufacturing equipment of the third embodiment shown in FIG. 4, the electrolysis chamber 8 is further combined with the reduction chamber 1. However, the other configuration is substantially the same as the titanium manufacturing facility of the third embodiment.

[0063] Electrolysis chamber 8 is formed on the opposite side of chloride chamber 7 with reduction chamber 1 interposed therebetween, and no partition wall is provided between the two. The electrolysis chamber 8 includes a graphite anode 12 and an iron cathode 13. The cathode side and the cathode side are separated by a partition 9. The cathode side is located on the side of the reduction chamber 1 and is continuous with the reduction chamber 1 without a partition wall. As in the case of the first embodiment, the partition 9 has a structure that allows the molten salt to pass through.

[0064] CaCl transferred from the chloride chamber 7 is introduced to the anode side. Chlorine gas by-produced on the anode side

2

Is sent to the chloride chamber 7. CaCl introduced to the anode side passes through the partition 9 and moves to the cathode side.

2

Move. That is, since the partition wall 9 allows the molten salt to pass through, a bath flow is generated in the electrolytic chamber 8 from the anode 12 side to the cathode 13 side with the supply of the molten salt to the anode side.

[0065] On the cathode side of the electrolysis chamber 8, Ca is generated on the surface of the iron cathode 13, and the generated Ca moves to the reduction chamber 1 while floating on the bath flow. A Ca reservoir 14 is provided near the bath surface from the cathode 13 to the reduction chamber 1 side. The Ca reservoir 14 is a box having an open bottom, and captures Ca generated on the surface of the cathode 13 and moving to the reduction chamber 1 side, thereby preventing the Ca from being exposed to the bath surface. The Ca stored in the Ca reservoir 14 is dissolved in CaCl in the reduction chamber 1 and

2

Used for the reduction reaction within 1.

[0066] In the fourth embodiment, the Ca reservoir 14 is made of iron like the cathode 13, and the Ca reservoir 14 is made of iron. It may be integrated with the cathode 13 so as to have the same potential. The purpose of providing the Ca reservoir 14 is not to expose the Ca layer to the bath surface. If the liquid surface on the reduction chamber side from the cathode 13 can be maintained in an insoluble gas atmosphere, exposing the Ca layer to the bath surface does not cause any problem.However, if air mixing cannot be avoided due to operational requirements, When the Ca layer is exposed on the bath surface, Ca〇 is generated by oxidation. Therefore, a Ca reservoir 14 was provided to avoid the generation of Ca〇 by oxidation.

Further, in the fourth embodiment, the upper portion of the partition wall 9 extends to the side of the cathode 13 and is in contact with the cathode 13. This is because Ca generated on the surface of the cathode 13 is generated between the cathode 13 and the partition wall 9. It is a structure to prevent accumulation in the water.

[0068] In the titanium production facility in which the electrolysis chamber 8 is combined with the reduction chamber 1, Ca can be easily transferred from the electrolysis chamber 8 to the reduction chamber 1. In particular, since the cathode side where Ca is generated in the electrolysis chamber 8 can be integrated with the reduction chamber 1, the partition can be eliminated from the opening of both chambers. For this reason, the facility structure is particularly simplified, and the size of the device can be reduced.

(Fifth Embodiment)

FIG. 6 is a diagram illustrating a configuration of a titanium manufacturing facility according to a fifth embodiment of the present invention. In the fifth embodiment, the configuration of the manufacturing facility of the fourth embodiment shown in FIG. 6 is such that the partition 9 of the electrolytic chamber 8 is eliminated. Other configurations are substantially the same as those of the titanium manufacturing facility of the fourth embodiment.

[0070] In the electrolysis chamber 8 integrated with the reduction chamber 1, the molten salt is introduced into the anode side as described above, so that a flow of the molten salt is formed from the anode 12 side to the cathode 13 side. For this reason, even if the partition 9 for partitioning between the anode side and the cathode example is omitted, a decrease in efficiency due to the backflow of the molten salt is prevented. However, the cathode 13 has a structure that allows the molten salt to pass therethrough, like the partition wall 9.

However, a curtain wall type partition wall 15 made of a chlorine-resistant gas material such as a refractory is provided above the cathode 13. Normally, it is conceivable to extend the cathode 13 above the liquid level in place of the newly provided partition wall 15, but in this case, there is a problem that the extension of the cathode 13 is corroded by chlorine gas generated on the anode side. . Therefore, it is necessary to provide the partition wall 15 separately from the cathode 13.

[0072] In the fifth embodiment, the partition wall 9 for separating the anode side and the cathode side in the electrolytic chamber 8 is omitted. Thereby, the facility structure can be further simplified, and the size can be further reduced. On the other hand, since no Ca reservoir is provided on the reduction chamber side of the cathode 13, it is necessary to maintain an insoluble gas atmosphere above the liquid level on the reduction chamber side from the cathode 13.

(Sixth Embodiment)

FIG. 7 is a diagram illustrating a configuration of a titanium manufacturing facility according to a sixth embodiment of the present invention. FIG. 8 is a diagram illustrating a cross-sectional configuration of the titanium manufacturing facility shown in FIG. 7 in the XX view. The sixth embodiment has a configuration in which the electrolysis chamber 8 is united with the reduction chamber 1 as in the fourth and fifth embodiments, but the reduction chamber 1 is formed in a cylindrical shape and the electrolysis chamber 8 is It has a cylindrical shape on the outside.

[0074] The electrolytic chamber 8 provided in a cylindrical shape outside the reduction chamber 1 has a cylindrical anode serving also as an outer wall.

12 and a cylindrical cathode 13 also serving as an inner wall. The total amount of Ca〇 and Ca-free CaCl obtained in the chloride chamber 7 placed beside the reduction chamber 1 is the anode 12 and the cathode 13

2

Is introduced into the annular space. The inner cathode 13 also serves as a part of the cylindrical outer wall of the reduction chamber 1, and the inside thereof is integrated with the reduction chamber 1.

As shown in FIG. 8, the cathodes 13 in the sixth embodiment are arranged in a spiral shape in the circumferential direction, and slits 13a are provided at predetermined intervals between the cathodes 13. The slits 13a allow the molten salt to pass from the outside to the inside, and the interval gradually increases from the inside to the outside. With the configuration of the slit 13a, a swirling flow is formed outside and inside the cathode 13, and the flow of the molten salt from the outside to the inside is promoted.

[0076] Above the cathode 13, a cylindrical partition wall 15 made of a chlorine-resistant gas material such as a refractory is continuously provided. For the same reason as in the fifth embodiment, it is necessary to provide the partition wall 15 separately from the cathode 13.

In the sixth embodiment, a swirling flow is generated on the outer surface side of the cylindrical cathode 13,

The molten salt flowing into the inside of the cathode 13 descends in the reduction chamber 1 while swirling, so that Ca generated on the surface of the cathode 13 is smoothly drawn into the inside of the cathode 13. Then, the Ca flowing into the inside of the cathode 13 floats on the CaCl in the reduction chamber 1, is dissolved in the CaCl, and dissolved.

twenty two

Ca contributes to the reduction reaction in the reduction chamber 1. [0078] By forming the electrolysis chamber 8 combined with the reduction chamber 1 in an annular shape outside the reduction chamber 1, the area of the anode 12 and the cathode 13 in the electrolysis chamber 8 can be increased, and more efficient Equipment design becomes possible. In this case, the entire amount of CaCl obtained in Shiojiro room 7 was introduced into electrolysis room 8

2

It is also possible to introduce some of that power.

[0079] Although the case where titanium metal is produced has been described above, examples of the metal that is an object of the present invention include tungsten, niobium, tantalum, chromium, zirconium, and neodymium in addition to the titanium. .

Industrial potential

According to the metal production method and the metal production apparatus of the present invention, in the direct oxide reduction method in which the metal oxide is reduced by Ca, the electrolysis is performed outside the reduction region, and the molten salt to be subjected to the electrolysis is used. By removing CaO, it is possible to avoid low productivity and deterioration of product quality due to carbon contamination, which are problems in the conventional direct oxide reduction method. This can greatly contribute to practical use in the field of metal production by the oxide reduction method.

Claims

The scope of the claims

[1] A metal oxide is charged into a molten salt containing CaCl as a main component and containing Ca,

2

Reducing the metal with Ca in the molten salt to produce a metal,

A separation step of separating the metal generated in the molten salt from the molten salt,

A salting step of salting the molten salt after separating the metal with chlorine gas to salinate by-product CaO in the molten salt;

Electrolyze the molten salt after the salt treatment to generate CaCl force Ca and chlorine,

2

An electrolysis step of sending the formed Ca or a molten salt containing the Ca to the reduction step.

[2] A metal oxide is introduced into a molten salt containing CaCl as a main component and containing Ca,

2

Reducing the metal with Ca in the molten salt to produce a metal,

2

Electrolysis step of sending the formed Ca or a molten salt containing the Ca to the reduction step,

In the reduction step, a metal production method in which generated metal is settled, and the settled metal is extracted together with a molten salt and transported to a separation step.

3. The metal production method according to claim 1, wherein the metal is any one of titanium, tungsten, niobium, tantalum, chromium, zirconium, and neodymium.

4. The metal production method according to claim 1, wherein a part of the molten salt after the salt treatment is sent to an electrolysis step, and the remaining molten salt is sent to a reduction step.

5. The metal production method according to claim 1, wherein chlorine gas generated in the electrolysis step is used in the chlorination step.

6. The metal production method according to claim 1, wherein in the electrolysis step, an electrolysis chamber in which an anode side and a cathode side are separated by a partition wall is used.

[7] The method according to claim 6, wherein the molten salt flows toward the cathode side from the anode side in the electrolysis chamber. Metal manufacturing method.

[8] The metal separated from the molten salt is rinsed with a part of the CaCl that has been subjected to the above salt step.

2

3. The metal production method according to claim 1, further comprising a rinsing step.

[9] The metal production method according to claim 1, wherein in the separation step, the molten salt metal is separated by physical compression and compaction.

[10] The metal production method according to claim 1 or 2, further comprising a melting step of dissolving the metal obtained in the separation step in an insoluble atmosphere to form an ingot.

[11] A metal salt containing CaCl as a main component and holding a molten salt containing Ca, and charged into the molten solution

2

A reduction chamber that generates a metal by reducing the chloride with Ca in the molten salt,

Means for separating the metal formed in the molten salt from the molten liquid,

Holding a molten salt from which metal has been separated and removed, subjecting the molten salt to chlorine treatment with chlorine gas, and salting a by-product CaO in the molten salt;

The molten salt after the chlorination treatment is retained, the molten salt is electrolyzed, and CaCl

An electrolysis chamber that produces 2 and chlorine;

Means for transferring generated Ca or a molten salt containing the Ca from the electrolysis chamber to the reduction chamber.

[12] A metal salt containing CaCl as a main component and holding a molten salt containing Ca, and charged into the molten salt

2

Means for separating the metal formed in the molten salt by molten salt force;

An electrolysis chamber that produces 2 and chlorine;

Means for transferring generated Ca or a molten salt containing the Ca from the electrolysis chamber to the reduction chamber, wherein the chloride chamber is integrated with the reduction chamber.

[13] A metal salt containing CaCl as a main component and holding a molten salt containing Ca, and charged into the molten salt

2

Means for separating the metal formed in the molten salt by molten salt force; Holding a molten salt from which metal has been separated and removed, subjecting the molten salt to a chlorine treatment with chlorine gas, and salting a by-product CaO in the molten salt;

An electrolysis chamber that produces 2 and chlorine;

Means for transferring generated Ca or a molten salt containing the Ca from the electrolysis chamber to the reduction chamber, wherein the electrolysis chamber is integrated with the reduction chamber.

14. The metal manufacturing apparatus according to claim 11, wherein the electrolytic chamber has a partition wall between the anode side and the cathode side, through which a molten salt can flow.

15. The metal production according to claim 13, wherein a cathode side of the electrolysis chamber is integrated with the reduction chamber.

16. The metal manufacturing apparatus according to claim 15, wherein the electrolysis chamber is configured so that a molten salt put on the anode side can flow to the reduction chamber via the cathode.

17. The method according to claim 16, further comprising a Ca reservoir for retaining Ca in the liquid on the reduction chamber side from the cathode.

18. The metal manufacturing apparatus according to claim 15, wherein the electrolysis chamber is formed in an annular shape around a reduction chamber formed in a cylindrical shape.

19. The metal manufacturing apparatus according to claim 18, wherein the electrolysis chamber has an outer cylinder also serving as an anode, and an inner cylinder also serving as a cathode, through which a molten salt can flow, and the inside of which is a reduction chamber.