WO2007034645A1

WO2007034645A1 - PROCESS FOR PRODUCING Ti AND APPARATUS THEREFOR

Info

Publication number: WO2007034645A1
Application number: PCT/JP2006/316355
Authority: WO
Inventors: Tadashi Ogasawara; Makoto Yamaguchi; Toru Uenishi; Masahiko Hori; Kazuo Takemura; Katsunori Dakeshita
Original assignee: Osaka Titanium Technologies Co., Ltd.
Priority date: 2005-09-20
Filing date: 2006-08-22
Publication date: 2007-03-29
Also published as: AU2006293354A1; CA2623212A1; NO20081519L; JP2007084847A; EA200800867A1; US20100089204A1; EP1944383A4; CN101268204A; EP1944383A1

Abstract

A process for producing Ti, comprising the reduction step of providing a molten salt containing CaCl2 and having Ca dissolved therein and reacting TiCl4 with the Ca to thereby form Ti particles, the separation step of separating the Ti particles formed in the molten salt from the molten salt and the electrolysis step of electrolyzing the molten salt so as to increase the concentration of Ca, wherein the molten salt having the concentration of Ca increased in the electrolysis step is introduced in a regulation vessel to thereby render the Ca concentration of the molten salt constant and thereafter is used in the reduction ofTiCl4 in the reduction step. In this process, not only can any fluctuation of Ca concentration of molten salt charged in a reduction vessel be suppressed but also a high concentration thereof can be maintained. Further, continuous processing of a large volume of molten salt becomes feasible. Therefore, the reduction reaction of TiCl4 can be efficiently performed, and as a process for realization of Ti production on an industrial scale, the process can be effectively utilized in the production of Ti by Ca reduction.

Description

Ti manufacturing method and manufacturing apparatus

Technical field

[0001] The present invention relates to a Ti production method for producing metal Ti by reducing TiCl with Ca, and

Four

And a manufacturing apparatus used therefor.

Background art

[0002] As an industrial production method of metal Ti, a crawl method in which TiCl is reduced with Mg is common.

Four

is there. In this crawl method, metal Ti is manufactured through a reduction process and a vacuum separation process. In the reduction process, liquid TiCl supplied from above in the reaction vessel is melted by molten Mg.

Four

Reduced, particulate metal Ti is generated, and then sinks downward to obtain sponge-like metal Ti. In the vacuum separation process, sponge metal T unreacted Mg and by-product MgCl in the reaction vessel are removed.

2

[0003] In the production of metal Ti by the crawl method, it is possible to produce a high-purity product.

However, since it is a Notch type, the manufacturing cost increases and the product price becomes very high. One reason for the increased manufacturing cost is that it is difficult to increase the supply rate of TiCl.

Four

[0004] There are several possible reasons for this. One is to increase the supply rate of TiCl too much

Four

Then, TiCl will be supplied from above to MgCl remaining on the liquid surface without settling,

twenty four

The supplied TiCl reacts as unreacted TiCl gas or insufficiently reduced TiCl gas.

4 4 3 It is discharged to the outside of the vessel, and the utilization efficiency of TiCl decreases.

Four

[0005] In the crawl method, the reaction is performed only in the vicinity of the surface of the molten Mg liquid in the reaction vessel, so that the heat generation area is narrow. Therefore, if TiCl is supplied at high speed, the cooling will not be in time.

Four

This is also a major reason that the TiCl supply rate is limited.

Four

[0006] Further, due to the wettability (adhesiveness) of molten Mg, the generated Ti powder settles in an aggregated state, and during the sedimentation, it is sintered by the heat of the high-temperature melt and grows. However, it is difficult to recover outside the reaction vessel. For this reason, metal Ti cannot be manufactured continuously, and productivity is hindered.

[0007] Regarding a Ti manufacturing method other than the crawl method, US Pat. No. 2,205,854 discloses Ti It is described that it is possible to use, for example, Ca in addition to Mg as a reducing agent for CI. And

Four

As a method for producing Ti using a reduction reaction with Ca, US Pat. No. 4,820,339 (hereinafter referred to as “Literature 1”) holds a molten salt of CaCl in a reaction vessel and the molten salt.

2

The upper force also supplies metallic Ca powder to dissolve Ca in the molten salt, and TiCl gas is supplied from below to react the dissolved Ca and TiCl in the molten CaCl salt.

4 2 4

Are listed.

[0008] However, in the method described in the above-mentioned document 1, the metal Ca powder used as the reducing agent is extremely expensive, and when purchased and used, the production cost is higher than that of the crawl method. Therefore, it cannot be established as an industrial Ti manufacturing method. It is difficult to handle Ca, which is highly reactive, and this is also a major factor that hinders the industrial process of Ti production by Ca reduction.

[0009] As yet another Ti production method, US Pat. No. 2,845,386 (hereinafter referred to as “Reference 2”) describes Olson's method in which TiO is directly reduced by Ca without passing through TiCl.

4 2

It is. This method is a kind of direct oxide reduction method. However, this method requires the use of expensive high-purity TiO.

2

[0010] On the other hand, in order to industrially establish a Ti production method by Ca reduction, the present inventors need to reduce Ti C1 with Ca, and the Ca in the molten salt consumed in the reduction reaction is reduced. Economic

Four

In JP-A-2005-133195 (hereinafter referred to as “Reference 3”) and JP-A-2005-133196 (hereinafter referred to as “Reference 4”),

2 In addition to using Ca produced by electrolysis, we proposed a method of circulating this Ca, that is, the “OYIK method”. In Reference 3 above, Ca is generated and replenished by electrolysis, Ca-rich molten CaCl is introduced into the reaction vessel, and Ti particles are reduced by Ca reduction.

2

The method used for the production of the above is described, and the above-mentioned document 4 further shows a method for effectively suppressing the back reaction accompanying electrolysis by using an alloy electrode (for example, Mg—Ca alloy electrode) as the cathode. It has been.

Disclosure of the invention

[0011] As described above, much research and development has been conducted on Ti production methods other than the crawl method. In particular, in the “OYIK method” proposed by the present inventors, TiCl The power to consume Ca in the molten salt during the reduction reaction of the metal If the molten salt is electrolyzed, Ca is generated in the molten salt, and the Ca thus obtained is reused in the reduction reaction from the outside. This eliminates the need to replenish Ca, and there is no need to remove Ca alone, improving economic efficiency.

[0012] Therefore, the present inventors based on this OYIK method as a basic configuration, and further developed a metal Ti manufacturing process that can perform stable and efficient operation, and the entire manufacturing process. It was decided to add a study. The OY or Ti alloy manufacturing method of the present invention, which is a further evolution of the OYIK method, took the initials of four people who were deeply involved in the development and completion of the idea, “Ogasawara, Yamaguchi, Takahashi, Kanazawa”. The name of the law (Ouitsuku II method).

[0013] An object of the present invention is to reduce TiCl with Ca generated by electrolysis of molten CaCl.

twenty four

In the production of Ti metal by Ca reduction, TiCl reduction reaction can be performed efficiently and industrial

Four

The purpose is to provide a Ti manufacturing method capable of stable operation and a manufacturing equipment used therefor.

[0014] The above-mentioned problem, that is, the reduction reaction of TiCl is efficiently performed and the operation is stable.

Four

In order to make it possible, the CaCl-containing molten salt introduced into the reduction tank that reduces TiCl

4 2

Increasing the Ca concentration and suppressing fluctuations in concentration are important, and in order to enable the production of Ti on an industrial scale, the rate of Ca supply to the reduction tank is increased (in other words, in the electrolysis process). Continuous treatment of a large amount of molten salt containing CaCl is required.

2

[0015] When the Ca concentration of the molten salt charged into the reduction tank is too low, unreacted TiCl gas is added to the tank.

4 It is discharged outside. In addition, a low salt-titanium gas such as TiCl or TiCl is generated to produce molten salt.

3 2

This molten salt was returned to the electrolytic cell that electrolyzes CaCl to produce Ca.

2

Occasionally, Ti is formed by the reaction between the generated Ca and lower salt titanium, and this Ti precipitates on the surface of the force sword, and depending on the shape of the electrolytic cell, the short circuit between the electrodes may occur in the cell. May cause blockage. There is also concern about the occurrence of TiC, which causes Ti contamination of C.

[0016] On the other hand, when the Ca concentration of the molten salt is too high, a large amount of Ca is contained in the molten salt extracted from the reducing tank, and Ti is also contained in Ti separated by the molten salt force in the separation process. Some of the molten salt will remain attached. This residual molten salt is completely removed when the separated and recovered Ti is melted, but the Ca is evaporated and lost, and it adheres to the inner wall of the melting furnace. It is necessary to remove a large amount of cleaning.

[0017] Since the Ca concentration in the molten salt after Ti is separated in the separation process is also high, the reaction (back reaction) between this Ca and the chlorine generated by the electrolysis occurs when returning to the electrolytic cell. Occurs and current efficiency decreases. In addition, the reaction heat at that time may disturb the temperature uniformity of the molten salt (bath salt) in the electrolytic cell, which may hinder the temperature control of the bath salt.

[0018] Therefore, the Ca concentration of the molten salt charged into the reduction tank does not change and is always constant, and it is desirable that the concentration be high in order to allow the reduction reaction to proceed efficiently. However, for example, it is very difficult to control the Ca concentration constantly while measuring the Ca concentration in the molten salt extracted from the electrolytic cell force in real time. Variations in concentration are inevitable. Therefore, it is difficult to keep the Ca concentration constant at all times as long as the molten salt with the Ca concentration increased in the electrolytic cell is directly put into the reduction tank.

[0019] Therefore, the present inventors have made various studies in order to suppress the fluctuation of the Ca concentration of the molten salt charged into the reduction tank and maintain it at a high concentration. As a result, an adjustment tank equipped with a Ca supply source was installed between the electrolytic cell (hereinafter referred to as the “main electrolytic cell”) and the reduction tank, and molten salt with an increased Ca concentration was introduced into the adjustment cell in the main electrolytic cell. It was found that it is effective to use it for reduction after keeping the Ca concentration constant. It was also found that a molten Ca-Mg alloy is suitable as a Ca supply source.

[0020] Further, as a result of detailed investigations on the shape of the electrolytic cell vessel of the main electrolytic cell, the electrode shape, the electrolysis conditions, the distance between the electrodes, etc., the molten salt flowed in one direction near the surface of the force sword. While recovering molten salt with increased Ca concentration on the outlet side of the main electrolyzer while maintaining electric current while maintaining high current efficiency by controlling the non-clearance, only the molten salt enriched with Ca is effective. It is possible to take out a large amount of CaCl-containing molten salt continuously.

2

I found out.

[0021] The present invention has been made based on these findings, and the gist of the present invention is the following (1) Ti production method and (2) Ti production apparatus.

[0022] (l) The above-mentioned molten TiCl is reacted with Ca in a molten salt containing CaCl and dissolved in Ca.

twenty four

A reduction step of generating Ti grains in the salt, and melting the Ti grains generated in the molten salt A separation process for separating the salt force, and an electrolysis process for increasing the Ca concentration by electrolyzing the molten salt whose Ca concentration has decreased due to the formation of Ti grains. In the electrolysis process, the Ca concentration is increased using the main electrolytic cell. The molten salt thus introduced is introduced into a regulating tank having a Ca supply source and brought into contact with the Ca supply source to make the Ca concentration of the molten salt constant, and then TiCl is reduced in the reduction step.

4 Original Ti manufacturing method.

[0023] Here, the "molten salt containing CaCl" means only molten CaCl or molten CaC.

twenty two

1 is a molten salt containing KC1, CaF, etc. to adjust the melting point and viscosity. Less than

twenty two

Hereinafter, it is also simply referred to as “molten salt”.

[0024] In the production method of the present invention, if the Ca supply source is a molten Ca-Mg alloy, it is desirable because Ca of the molten Ca-Mg alloy can be easily supplemented (hereinafter referred to as the first embodiment).

[0025] In the first embodiment, the Ca concentration in the molten Ca-Mg alloy is the same as that of the molten CaCl-containing alloy.

2 If the salt is increased by electrolysis in an alloy electrolytic cell and Ca is replenished, Ca can be easily replenished without affecting the operation (hereinafter referred to as the second embodiment).

) o

[0026] In the production method of the present invention, the molten salt from which the Ti grains have been separated in the separation step is once charged into the electrolytic cell for alloying, and the Ca concentration of the molten salt is reduced. If it is put into the main electrolytic cell, it is desirable because the residual Ca in the molten salt returned to the electrolysis process from the separation process can be removed and this residual Ca can be used effectively (hereinafter referred to as the first). 3).

[0027] Further, if the adjustment tank used in the production method of the present invention has a cooling function, an increase in the temperature in the tank based on an exothermic reaction can be mitigated in a later reduction tank, and the addition to the reduction tank Therefore, the Ca concentration of the molten salt can be kept constant at a constant and high concentration, and the reduction reaction can be performed efficiently, contributing to stable operation (hereinafter referred to as the fourth embodiment).

[0028] (2) A molten salt containing CaCl and dissolved in Ca is retained and supplied into the molten salt.

2

A reduction tank for reacting TiCl with the Ca to produce Ti grains, and

Four

Separating means for separating the formed Ti grains from the molten salt, and holding the molten salt after the Ti grains are separated, comprising an anode and a power sword, and performing electrolysis in the molten salt to form a cathode A main electrolytic cell for generating Ca on the side and a Ca supply source; after introducing the molten salt in the main electrolytic cell and bringing it into contact with the Ca supply source, the Ca concentration of the molten salt is made constant And an adjusting tank for introducing the molten salt into the reduction tank.

[0029] In the production apparatus of the present invention, if the Ca supply source is a molten Ca-Mg alloy and includes an alloy electrolytic cell for increasing the Ca concentration of the molten Ca-Mg alloy, the first and It can be suitably used for implementing the Ti manufacturing method according to the second embodiment.

[0030] In addition, an electrolytic cell for an alloy is installed between the high-temperature decanter and the main electrolytic cell in the separation step, and the molten salt having a high Ca concentration in the alloy electrolytic cell can be introduced into the adjustment tank. V is suitable for carrying out the Ti manufacturing method according to the third embodiment.

[0031] In the production method of the present invention, the molten salt with the Ca concentration increased in the main electrolytic cell is introduced into the adjustment tank equipped with the Ca supply source and the Ca concentration is made constant, and then used for the reduction of TiCl. Throw

Four

The fluctuation of the Ca concentration of the molten salt entering can be suppressed and maintained at a high concentration. As a result, the reduction reaction of TiCl can be performed efficiently and stable operation is possible. Electrolysis

Four

It is possible to continuously process a large amount of molten salt containing CaCl in the process and supply Ca to the reduction tank.

2

Ti can be produced on an industrial scale by increasing the feed rate. This manufacturing method can be easily and suitably performed by the manufacturing apparatus of the present invention.

Brief Description of Drawings

FIG. 1 is a diagram showing a schematic configuration example of the Ti manufacturing apparatus of the present invention.

FIG. 2 is a diagram showing another schematic configuration example of the Ti manufacturing apparatus of the present invention.

Fig. 3 is an explanatory diagram of the replenishment of Ca to the molten Ca-Mg alloy in the alloy electrolytic cell.

FIG. 4 is a diagram showing a schematic configuration example of the Ti manufacturing apparatus of the present invention in which an alloy electrolytic cell is incorporated.

FIG. 5 is a diagram showing a schematic configuration example of the Ti production apparatus of the present invention in which an alloy electrolytic cell is incorporated in the molten salt path returned from the separation step to the main electrolytic cell.

FIG. 6 is a longitudinal sectional view showing a configuration example of a main part of an electrolytic cell used when performing the molten salt electrolysis method used in the present invention.

Fig. 7 shows the hollow-force sword used in carrying out the molten salt electrolysis method used in the present invention. It is a figure which shows typically the structural example of a part of used electrolytic vessel.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the production method and production apparatus of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration example of the Ti manufacturing apparatus of the present invention. As shown in FIG. 1, this apparatus holds a molten salt containing CaCl and dissolved in Ca and supplying the molten salt to the molten salt.

2

The reduction tank 1 for generating Ti grains by reacting the supplied TiCl with the Ca, and the melting

Four

Separation means for separating the Ti grains formed in the salt from the molten salt, and the molten salt after the Ti grains are separated are held, and the anode 2 and the force sword 3 are provided. A main electrolytic cell 5 for decomposing and generating Ca on the cathode side; and a Ca supply source. After introducing the molten salt in the main electrolytic cell 5 to make the Ca concentration of the molten salt constant, And an adjustment tank 6 for introducing the molten salt into the reduction tank 1. Further, in this example, a diaphragm 4 is provided between the anode 2 and the force sword 3 of the main electrolytic cell 5.

In the manufacturing apparatus shown in FIG. 1, a decanter type centrifugal sedimentator (high temperature decanter) 7 and a separation tank 8 are used as the separation means.

[0036] In the production method of the present invention, TiCl is added to Ca in a molten salt containing CaCl and dissolving Ca.

2 4 A reduction step of reacting to produce Ti particles in the molten salt, a separation step of separating the Ti particles produced in the molten salt from the molten salt, and a Ca concentration accompanying the production of Ti particles. An electrolytic process for increasing the Ca concentration by electrolyzing the molten salt having a reduced concentration, and introducing the molten salt having the Ca concentration increased using the main electrolytic cell in the electrolysis process to the adjustment tank having the Ca supply source. The molten salt is made constant by bringing the molten salt into contact with the Ca supply source and then used for the reduction of TiCl in the reduction step.

Four

That is, in the “reduction step” of the production method of the present invention, for example, the apparatus shown in FIG. 1 is used. First, a molten salt in which Ca supplied from the adjustment tank 6 is dissolved at a constant concentration is reduced. Retained in tank 1 and reacted with TiCl supplied from TiCl supply port 9 to Ca in the molten salt,

4 4

Ti grains are formed in the molten salt.

[0038] In this case, the molten salt is not held in a stationary state in the reducing tank 1, but is held while gradually flowing down from above the reducing tank 1, while TiCl is added to the Ca in the molten salt. In Reduced to produce Ti grains.

[0039] The Ti particles generated in the reduction step are separated from the molten salt in the "separation step". In the separation process, Ti particles are first separated and recovered from the molten salt in a high-temperature decanter 7 and then separated in a separation tank 8.

The molten salt adhering to the Ti grains is removed.

[0040] The decanter type centrifugal settling machine is a type of centrifugal separator that spins down suspended matter by rotating a rotating cylinder at high speed. It can process at high speed and has high dehydration performance. Used in various processing plants. A type capable of high temperature treatment has also been developed and can be applied as a high temperature decanter 7 in this separation process.

[0041] The Ti grains extracted from the high-temperature decanter 7 are heated and melted by the plasma irradiated from the plasma torch 10 in the separation tank 8, and are poured into the vertical mold 11 to become a Ti ingot 12. On the other hand, there is a possibility that Ti fine particles are mixed in the adhered molten salt separated by Ti grain force. For this reason, there is a possibility that a problem may occur if this adhered molten salt is returned to the electrolysis process, so it is desirable to return it to the reducing tank 1 as shown in FIG. Power! In addition, since there is a certain amount of Ca remaining in the adhering molten salt, it is reasonable to return it to the reduction tank 1 from the viewpoint of effective utilization of Ca. Note that the flow rate of the adhering molten salt is very small compared to the flow rate of the molten salt introduced into the reduction tank 1 after the Ca concentration is made constant in the adjustment tank 6, so that the flow from the adjustment tank 6 to the reduction tank 1 Variations in the Ca concentration of the molten salt introduced are negligible.

The molten salt having a reduced Ca concentration separated by the high-temperature decanter 7 is returned to the “electrolysis step”, and is introduced and held between the force sword 3 and the diaphragm 4 in the main electrolytic cell 5. The configuration and operation of the main electrolytic cell 5 used in this step will be described in detail later. In this case, the molten salt is not held in the main electrolytic cell 5 in a stationary state, but the main electrolytic cell 5 It is held while gradually flowing down from above, and is electrolyzed during that time, increasing the molten salt Ca concentration.

[0043] However, a change in Ca concentration due to a slight change in electrolysis conditions in the main electrolytic cell 5 is inevitable. For this reason, when the molten salt that has been subjected to the electrolytic treatment in the main electrolytic cell 5 is directly charged into the reducing cell 1, the Ca concentration is not always maintained constant. The current efficiency may decrease due to the action. The efficiency of the reduction reaction may be reduced, and stable operation may be difficult.

[0044] Therefore, in the production method of the present invention, the molten salt in which the Ca concentration is increased using the main electrolytic cell 5 in the electrolysis step is introduced into the adjustment tank 6 having a Ca supply source, and the Ca supply source is introduced. After making the Ca concentration of the molten salt constant by bringing it into contact, it is used for the reduction of TiCl in the reduction step.

Four

As the Ca supply source, molten metal Ca or molten Ca—Mg alloy can be used. In other words, molten metal Ca or molten Ca—Mg alloy is allowed to float on the molten salt with increased Ca concentration, and these Ca supply source and molten salt are brought into contact with each other. As a result, when the Ca concentration of the molten salt is less than its saturation solubility, the Ca supply source Ca can be supplied to the molten salt, and the Ca concentration can be maintained at a concentration close to the saturation solubility. If the Ca concentration of the metal is the saturation solubility, and precipitated metal Ca is also present, the metal Ca floats and separates due to the difference in specific gravity in the adjustment tank 6, and the Ca concentration is maintained at a concentration close to the saturation solubility. be able to. Furthermore, if the temperature of the molten salt at the time of extraction from the adjustment tank 6 is controlled to be constant, the Ca concentration can be controlled to a constant concentration near the saturation solubility at that temperature.

Therefore, regardless of whether the Ca concentration of the molten salt is the saturation solubility or less, the adjusting tank 6 is installed, and the molten salt with an increased Ca concentration is introduced into the main electrolytic tank 5. As a result, molten salt with a constant Ca concentration near its saturation solubility was charged into the reduction tank 1, and TiCl

The reduction reaction of 4 can be carried out efficiently and stable operation can be achieved.

[0047] However, if electrolysis is performed in the main electrolytic cell 5 until the Ca concentration exceeds the saturation solubility, metallic Ca precipitates inside the main electrolytic cell 5, which may cause troubles such as the clogging of the electrolytic cell described above. is there. Therefore, when increasing the Ca concentration in the main electrolytic cell 5, electrolysis is performed while controlling the Ca concentration so that it does not exceed the saturation solubility. It is desirable to introduce salt into the adjustment tank 6 and bring it into contact with the Ca supply source so that the Ca concentration is a constant concentration in the vicinity of the saturation solubility.

[0048] FIG. 2 is a diagram showing another schematic configuration example of the manufacturing apparatus of the present invention used when the Ti manufacturing method is carried out, similarly to the manufacturing apparatus shown in FIG. The difference from the apparatus configuration shown in FIG. 1 is that a sedimentation separation tank (thickener) 13 using gravity is used instead of a high temperature decanter as a separation means, which is wider than the case where a high temperature decanter is used. Although an installation area is required, there is an advantage that the power cost is small. [0049] The first embodiment of the production method of the present invention is a method in which the Ca supply source is a molten Ca-Mg alloy. If the Ca supply source is a molten Ca-Mg alloy, when the molten Ca-Mg alloy power is also dissolved into the molten salt and it becomes necessary to replenish Ca in the alloy, it is easily replenished as described below. It is desirable because it can.

[0050] A second embodiment of the present invention is a method of increasing the Ca concentration in a molten Ca-Mg alloy by electrolyzing a molten salt containing CaCl in an alloy electrolytic cell in the first embodiment.

2

The

[0051] FIG. 3 is an explanatory diagram of the replenishment of Ca to the molten Ca—Mg alloy by the alloy electrolytic cell. In Fig. 3, the electrolytic cell 14 for alloy hinders the movement of molten salt (molten CaCl).

2

In order to prevent damage, the partition 15 is divided into an anode side and a force sword side by a partition 15 having an opening on the lower side. An anode 2 is attached to the anode side, and the force sword side has a lower specific gravity than molten CaCl.

2

The molten Ca-Mg alloy 16 constitutes a power sword. An electrode rod 17 is inserted into the molten Ca—Mg alloy 16. On the other hand, a molten salt whose Ca concentration has been increased in the electrolysis process is introduced into the adjustment tank 6, and a molten Ca—Mg alloy 16 serving as a Ca supply source is held thereon.

[0052] When the molten CaCl is electrolyzed using this electrolytic cell 14 for alloy, the anode 2 has chlorine gas.

2

Ca is generated at the interface between molten Ca—Mg alloy 16 and molten CaCl, which is a force sword.

2

To do. Since a voltage is applied between the molten Ca-Mg alloy 16 and the electrolytic cell (a potential difference is generated), the generated Ca does not dissolve in the molten CaCl, and the molten Ca-Mg alloy 16

2

The Ca concentration of the Ca-Mg alloy 16 increases.

[0053] Therefore, the molten Ca—Mg alloy 16 having an increased Ca concentration is transferred to the upper part of the molten Ca—Mg alloy 16 in the adjustment tank 6 (indicated as “MgZCa” in FIG. 3), and is moved to the lower part. The existing Ca is supplied to the molten salt (ie, melted out), and the molten Ca—Mg alloy 16 having a reduced Ca concentration is returned to the molten Ca—Mg alloy 16 in the alloy electrolytic cell 14 (in FIG. 3, “Mg”). In the electrolytic cell 14 for alloy, the Ca generated by the electrolysis of the molten CaCl described above is molten Ca.

2

— Absorption by Mg alloy 16 increases Ca concentration.

As described above, if the second embodiment of the present invention is applied, the replenishment of Ca to the molten Ca—Mg alloy used as the Ca supply source can be easily performed without affecting the Ca production process. Can be done.

FIG. 4 is a diagram showing a schematic configuration example of a manufacturing apparatus in which the alloy electrolytic cell shown in FIG. 3 is incorporated in order to carry out the manufacturing method of the present invention. If the first and second embodiments of the present invention are applied using this apparatus, Ca can be easily replenished to the molten Ca—Mg alloy used as the Ca supply source without affecting the operation. it can.

[0056] In carrying out the production method of the present invention, if the molten salt is operated under reducing conditions such that the Ca concentration of the molten salt is too low and Ca is completely consumed in the reduction of TiCl, as described above, , TiCl

Four

4 is discharged out of the tank as unreacted gas, and lower titanium chloride is generated. Therefore, it is desirable to adjust the supply amount of TiCl and Ca so that a minute amount of Ca remains. Only

Four

However, if molten salt with a small amount of Ca remaining is introduced into the main electrolytic cell, there is a concern that current efficiency may decrease due to back reaction between the residual Ca and chlorine generated by electrolysis in the main electrolytic cell. The

[0057] In the third embodiment of the present invention, using the alloy electrolytic cell used in the second embodiment, the molten salt after the Ti grains are separated in the separation step is once charged into the alloy electrolytic cell. In this method, the Ca concentration of the molten salt is reduced and charged to the main electrolytic cell, and concerns such as a decrease in current efficiency due to the knock reaction can be eliminated.

FIG. 5 is a diagram showing a schematic configuration example of a manufacturing apparatus in which an alloy electrolytic cell is incorporated in the molten salt path returned from the separation step to the main electrolytic cell in the schematic configuration example shown in FIG. As shown in Fig. 5, an electrolytic cell 14 for the alloy is installed between the high-temperature decanter 7 and the main electrolytic cell 5 used in the separation process, and the molten salt after the Ti grains are separated and recovered is temporarily separated from this alloy. Into the electrolytic cell 14 for use. Since a voltage is applied between the molten Ca-Mg alloy 16 in the electrolytic cell 14 for the alloy and the electrolytic cell, the Ca remaining in the molten salt is absorbed by the molten Ca-Mg alloy 16 by electrophoresis and is contained in the molten salt. Ca is removed. This molten salt with reduced Ca concentration is put into the main electrolytic cell 5.

[0059] FIG. 5 shows a force illustrating an example in which an alloy electrolytic cell 14 is installed between the high-temperature decanter 7 and the main electrolytic cell 5. In the apparatus shown in FIG. 2, the thickener 13 and the main electrolytic cell 5 An electrolytic cell 14 for alloy may be installed between them.

[0060] When the third embodiment is employed in carrying out the manufacturing method of the present invention, the above-described main feature is achieved. In addition to suppressing the reduction in current efficiency due to back reaction in the electrolytic cell 5, Ca removed from the molten salt is absorbed by the molten Ca-Mg alloy 16 and used again in the adjustment tank 6 for TiCl reduction. Ca remaining in the salt can be used effectively.

Four

[0061] The fourth embodiment of the present invention is characterized in that the adjustment tank used in the production method of the present invention has a cooling function. By adopting this embodiment, the following two effects can be expected. One is to adjust the Ca concentration of the molten salt in the adjustment tank 6 and then use the TiCl Ca in the next reduction step.

The force that causes the reduction reaction by 4 The rise in the temperature in the reduction tank due to the heat generated by this reaction can be moderated to some extent by removing heat from the molten salt supplied to the reduction tank 1 in advance.

[0062] The other is that the saturated Ca solubility of the molten salt can be lowered by lowering the temperature of the molten salt in the adjusting tank 6. By this action, even if the Ca concentration of the molten salt introduced from the main electrolytic cell 5 to the adjustment tank 6 does not reach its saturation solubility, the saturation solubility can be reached by lowering the temperature in the adjustment tank 6. . Even if Ca precipitates due to cooling, it floats and becomes a source of Ca.

[0063] That is, if the molten salt supplied from the adjustment tank 6 is cooled and controlled so that its temperature is constant, the Ca concentration of the molten salt charged into the reducing tank 1 is always kept constant and the force is high. The concentration can be maintained, the TiCl reduction reaction can be performed efficiently, and stable operation is possible.

Four

Become.

[0064] The production apparatus of the present invention is a production apparatus used when the Ti production method described above is carried out, holds a molten salt containing CaCl and dissolved in Ca, and is supplied into the molten salt.

2

A reduction tank for reacting TiCl with Ca to produce Ti grains, and in the molten salt

Four

Separation means for separating the Ti grains generated from the molten salt, and the molten salt after the Ti grains are separated are retained, and an anode and a force sword are provided, and electrolysis is performed in the molten salt. A main electrolytic cell for generating Ca on the cathode side and a Ca supply source are provided, and the molten salt in the main electrolytic cell is introduced and brought into contact with the Ca supply source to make the Ca concentration of the molten salt constant. And a regulating tank for charging the molten salt into the reducing tank.

The apparatus configuration illustrated in FIGS. 1 and 2 is an embodiment of the manufacturing apparatus of the present invention. Thus, as described above, the production method of the present invention can be suitably implemented using this production apparatus.

The apparatus configuration shown in FIG. 4 is another schematic configuration example of the manufacturing apparatus of the present invention. As described above, the molten Ca—Mg alloy 16 is formed between the adjustment tank 6 and the alloy electrolytic tank 14. It is suitable for carrying out the Ti manufacturing method according to the first and second embodiments in which the molten Ca—Mg alloy used as a Ca supply source is replenished with Ca.

The apparatus configuration shown in FIG. 5 is still another schematic configuration example of the production apparatus of the present invention, and the alloy electrolytic cell 14 is interposed between the high-temperature decanter 7 and the main electrolytic cell 5 used in the separation process. In this way, the molten salt having a reduced Ca concentration in the alloy electrolytic cell 14 can be introduced into the main electrolytic cell 5. By using this apparatus, as described above, the Ti manufacturing method according to the third embodiment can be easily performed.

[0068] According to the production method and production apparatus of the present invention described above, it is possible to increase the concentration of Ca in the CaC1-containing molten salt to be introduced into the reduction tank and to suppress fluctuations in concentration.

2 4 The reaction can be performed efficiently and stable operation can be performed.

[0069] Further, in the production method of the present invention, in the electrolysis step, the molten salt is electrolyzed while gradually flowing down from the upper side of the main electrolytic cell, so that a large amount of molten salt can be continuously processed. As a result, the supply rate of Ca to the reduction tank is increased and Ti can be produced on an industrial scale.

[0070] Therefore, a molten salt electrolysis method capable of producing Ti on an industrial scale and an electrolytic cell used therefor will be described in detail.

FIG. 6 is a longitudinal sectional view showing a configuration example of a main part of an electrolytic cell used when the molten salt electrolysis method used in the present invention is carried out.

[0072] This electrolytic cell 5 has a pipe (cylindrical) shape that is long in one direction and holds a molten salt containing CaCl.

2

An electrolytic cell container 5a, a cylindrically shaped anode 2 and a cylindrical force sword 3 arranged in the container 5a along the longitudinal direction of the electrolytic cell container 5a, and the electrolytic cell container A molten salt supply port 20 is provided at one end (bottom plate 18) in the longitudinal direction of 5a, and a molten salt discharge port 21 is provided at the other end (upper cover 19). The anode surface and the force sword surface are opposed to each other in a substantially vertical direction, and further, between the anode 2 and the force sword 3, the molten salt A diaphragm 4 is provided to suppress the passage of the Ca generated by the electrolysis of. In addition, a cooler 22 is attached to the outer surface of the anode 2.

[0073] This electrolytic cell 5 is used as a main electrolytic cell in the production method of the present invention. In the molten salt electrolysis method performed using this electrolytic cell, a molten salt containing a metal fog forming metal chloride is continuously or intermittently supplied between the one-end force anode and the force sword of the electrolytic cell. In addition, the flow rate in one direction is given to the molten salt near the surface of the force sword, and the molten salt is electrolyzed while flowing in one direction near the surface of the force sword, thereby increasing the metal fog forming metal concentration of the molten salt.

[0074] The above-mentioned "metal fog forming metal" has a property that the metal itself dissolves in a metal salt salt such as Ca, Li, Na, A1, etc. (ie, Ca is CaCl And again Li

2

It is a metal that dissolves in LiCl) and reduces TiCl. These metals reduce TiCl

Since all of these work in the same way when Ti is produced, the following explanation will be given only when the metal fog forming metal is Ca.

[0075] In addition, as described above, the "molten salt containing a metal fog forming metal (Ca) chloride" refers to molten CaCl alone or to molten CaCl to adjust the melting point, viscosity, etc. To KC1

twenty two

It is a molten salt with CaF added.

2

[0076] In the molten salt electrolysis method, first, a molten salt containing CaCl is added to the electrolytic cell 5.

2

One-end force is also supplied between the anode 2 and the force sword 3 continuously or intermittently.

[0077] Since the electrolytic cell 5 is long in one direction and has a shape (in the example shown in the figure, it is elongated in the vertical direction! / Pipe (cylindrical) shape), the molten salt is applied to one end force of the electrolytic cell 5 Anode By supplying continuously or intermittently between 2 and force sword 3, it is possible to give a flow rate in one direction to the molten salt near the surface of force sword 3, and to allow the molten salt to flow in one direction near the surface of force sword. It becomes. In this case, it is sufficient that the molten salt near the surface of the force sword 3 flows in one direction. The entire molten salt between the anode 2 and the force sword 3 may flow in one direction. . The term “near the force sword surface” refers to a region adjacent to the force sword surface where Ca generated on the force sword surface is present.

[0078] Although the supply of the molten salt is usually performed continuously, the supply of the molten salt may be continued intermittently, that is, even if the supply of the molten salt is temporarily stopped in relation to the post-process or the like. Temporary stop of molten salt supply When stopped, the flow of the molten salt near the surface of the force sword is also stopped. Therefore, strictly speaking, the “flow velocity” when “giving a one-way flow velocity to the molten salt near the surface of the force sword” includes a state where the flow velocity is zero without any flow.

[0079] Subsequently, the molten salt is electrolyzed. In other words, the force electrolysis cell 5 in which molten salt is electrolyzed while flowing in the vicinity of the surface of the force sword to generate Ca on the surface of the force sword has a long shape in one direction. In the example shown, the distance between the anode 2 and the force sword 3 is made relatively small in order to keep the electrolysis voltage low, so the Ca concentration is low and the molten salt near the molten salt supply port 20 is electrolyzed with the molten salt. Mixing with the molten salt in the vicinity of the molten salt extraction port 21 having an increased concentration can be prevented, and only the molten salt enriched with Ca can be effectively extracted.

[0080] The technique described in Document 2 described above is based on the ability to use Ca for reduction.

4 2

This is a direct reduction method that reduces with Ca to Ti, and is different from the molten salt electrolysis method used in the present invention. Furthermore, the direct reduction method described in the above-mentioned document 2 is obtained because it is consumed as the carbon electrode force SCO as the anode and titanium carbide (TiC) is generated in the molten salt.

2

Since Ti contaminated with Ti is mixed into Ti and the workability deteriorates, it becomes a problem when this Ti is used as a wrought material.

[0081] Further, the document 2 describes a technique of "forming a molten salt flow in the vicinity of a force sword in the production of Ti by Ca reduction in a molten salt". However, when the anode and the force sword are placed facing each other along the longitudinal direction in the electrolytic cell, it is formed near the force sword surface or between the force sword surface and the diaphragm when a diaphragm is provided. In the force sword chamber, a unidirectional molten salt flow is formed along the surface of the force sword, and the molten salt with increased Ca concentration is recovered on the outlet side of the electrolytic cell by electrolysis in that state. N / A, and the description that suggests it is not shown! /.

[0082] Therefore, even though it is common in that the molten salt forms a unidirectional flow in the electrolytic cell, the molten salt electrolysis method used in the present invention and the technique described in the document 2 are completely different from each other. The

[0083] In this molten salt electrolysis method, the anode surface and the force sword surface face each other and are arranged in a substantially vertical direction, and a partition wall configured to allow a part of the diaphragm or the molten salt to flow between the anode and the force sword. If the electrolytic cell provided is used, it will be generated on the anode side. It is easy to collect the chlorine gas. Also, Ca and chlorine generated by electrolysis react with CaCl

This is desirable because it can suppress the knock reaction returning to 2. Note that “substantially” in the “substantially vertical direction” means “substantially” and “substantially”, and “substantially vertical direction” means the vertical direction or its directional force also in the horizontal direction. A slightly inclined direction.

[0084] The molten salt electrolysis method using the electrolytic cell in which both electrodes are arranged opposite to each other in a substantially vertical direction can be preferably carried out by using the electrolytic cell illustrated in FIG. In the electrolytic cell illustrated in Fig. 6, CaCl is supplied into the lower force tank 5 of the electrolytic cell 5 and extracted from above.

2

However, on the contrary, it is also possible to supply the upper force of the electrolytic cell 5 and extract it from below.

[0085] In the electrolytic cell used in the molten salt electrolysis method, the anode surface and the force sword surface are arranged in a substantially vertical direction, and the unidirectional flow rate is also applied to the molten salt near the force sword surface. Therefore, the flow direction of the molten salt is vertical, and the chlorine gas generated on the anode side floats easily, so it can be easily recovered.

[0086] Examples of the diaphragm provided between the anode and the force sword include, for example, many containing yttria (Y 2 O 3).

twenty three

A porous ceramic body can be used. A porous ceramic body made by firing yttria has a selective permeability that allows Ca and chlorine ions to pass through but does not allow metal Ca to pass through. It also reduces by Ca, which has strong reducing power. It has an excellent resistance to calcium reduction that is not possible, and is suitable as a diaphragm in the molten salt electrolysis method used in the present invention.

[0087] If an electrolytic cell in which such a diaphragm is provided between the anode and the force sword is used, Ca produced on the force sword side reacts immediately with chlorine produced on the anode (graphite) side and returns to CaCl.

2 Electrolysis can be carried out with high current efficiency at which knock reaction is unlikely to occur.

[0088] Instead of the diaphragm, a partition configured to allow a part of the molten salt to flow therethrough may be used. The partition wall does not allow molten salts such as Ca and chlorine ions as well as metallic Ca, but by providing slits or holes through which molten salt can pass in a part of the partition wall, electrolysis can be achieved, while metal Ca It is possible to limit knock reaction by restricting the passage to some extent.

[0089] In this molten salt electrolysis method, the force sword is hollow, has a gap or a hole through which the molten salt can flow from the surface of the force sword to the inside of the force sword, and the Ca concentrated molten salt flowing into the force sword is removed. An electrolytic cell with a force sword that can be pulled out of the electrolytic cell shall be used. If so, knock reaction can be effectively suppressed.

FIG. 7 is a diagram schematically showing a configuration example of a part of an electrolytic cell using a hollow force sword. As shown in FIG. 7, in this electrolytic cell, the anode 2 and the hollow force sword 3a face each other in the substantially vertical direction along the longitudinal direction in the electrolytic cell 5, and between the anode 2 and the force sword 3a. Is provided with a diaphragm 4. Although not shown, the force sword 3a is provided with a gap or a hole through which the molten salt can flow into the cathode as well as the force sword surface force.

[0091] If the electrolytic cell constructed in this way is used, the molten salt is extracted from above the hollow portion of the force sword 3a, so that the inner side of the force sword from the outer side as shown by the white arrow in the figure. A molten salt flow to the (hollow part) is formed, and Ca generated on the outer surface of the force sword 3a is immediately taken into the force sword 3a without diffusing and moving to the anode side. Thereby, back reaction can be effectively suppressed. Since the electrolytic cell illustrated in FIG. 7 has the diaphragm 4, the knock reaction suppressing effect is further increased as compared with the case without the diaphragm.

[0092] There are no particular limitations on the size and position of the gaps and holes provided in the hollow force sword. Considering the distance between the anode surface (diaphragm surface if a diaphragm is provided) and the outer surface of the force sword, the amount of molten salt extracted (the amount of molten salt supplied), etc. It is advisable to determine appropriately so that a molten salt flow to the side is formed.

[0093] Also, in this molten salt electrolysis method, if the molten salt in the electrolytic cell is controlled so that the Ca concentration is less than its saturation solubility, the Ca concentration is increased and TiCl

4 The production rate can be increased and adverse effects such as clogging inside the electrolytic cell can be suppressed. The above-mentioned “controlling the Ca concentration to be less than the saturation solubility” means “electrolysis under conditions where the Ca concentration is close to the saturation solubility and does not precipitate”.

[0094] Specifically, the shape of the electrolytic cell container and the electric power are set so that the "condition where the Ca concentration is close to the saturation solubility and does not precipitate" is satisfied at the site where the Ca concentration is highest in the electrolytic cell. The optimum electrolysis conditions according to the pole shape, the distance between the poles, and the amount of molten salt extracted per unit time will be determined empirically. In particular, when a diaphragm or partition wall is used between the anode and the force sword, the Ca concentration near the molten salt outlet on the force sword side is the highest, so the Ca concentration in this part is controlled to be less than the saturation solubility. To which part of the electrolytic cell Even if it does not cause metal Ca to be deposited, electrolytic operation becomes possible.

[0095] In order to satisfy this "condition in which the Ca concentration is close to the saturation solubility and does not precipitate", in the manufacturing method of the present invention, the molten salt with the increased Ca concentration in the electrolysis step is adjusted to have a Ca supply source. The molten salt is introduced into a tank and brought into contact with the Ca supply source, and the Ca concentration of the molten salt is kept high and constant. As described above, the optimum electrolysis conditions, the amount of molten salt withdrawn, etc. are determined empirically. Even so, a certain degree of control is possible.

[0096] When the molten salt electrolysis method used in the present invention is carried out, a large heat of reaction is generated in the electrolytic cell, so it is desirable to effectively remove the heat. Specifically, it is desirable to install a cooler at the center of the force sword to remove the reaction heat from the internal force of the force sword, regardless of whether or not the hollow force sword is used. As the cooler, for example, a tubular heat exchanger is suitable.

[0097] If a cooler (heat exchanger) is also installed on the anode side, the heat removal efficiency is further increased. The cooler 22 installed so as to surround the anode 2 shown in FIG. 6 is an example of this.

[0098] During electrolysis, the energized surface area needs to be increased in order to increase the energization amount and increase the amount of Ca generation. In the electrolytic cell illustrated in FIG. 6 above, it is desirable to provide fine irregularities on the inner surface in order to ensure a large and energized surface area in the electrolytic cell illustrated in FIG. . As a method for that purpose, for example, a groove process for forming a groove on the electrode surface can be applied.

[0099] According to the above-described molten salt electrolysis method, it is possible to relatively stably obtain a molten salt in which Ca is concentrated to near the saturation solubility while suppressing adverse effects such as clogging inside the electrolytic cell. Can be manufactured efficiently. In addition, since the molten salt is electrolyzed while flowing in one direction near the surface of the force sword, a large amount of molten salt can be processed continuously.

[0100] The electrolytic cell used for carrying out this molten salt electrolysis method retains a molten salt containing CaCl.

2

The electrolytic cell container has an anode and a force sword disposed along the longitudinal direction of the electrolytic cell container, and is melted at one end in the longitudinal direction of the electrolytic cell container. A salt supply port is provided so that the molten salt can be supplied between the anode and the power sword, and the molten salt having an increased Ca concentration generated by electrolysis of the molten salt at the other end is provided outside the electrolytic cell. There is an outlet for extracting molten salt. [0101] The electrolytic cell illustrated in Fig. 6 is an embodiment thereof, and the anode surface and the cathode surface are arranged to face each other in a substantially vertical direction, and a diaphragm is provided between the anode and the force sword. It has an electrolytic cell. Instead of the diaphragm, a partition wall configured to allow a part of the molten salt to flow therethrough may be provided.

[0102] If the electrolytic cell shown in Fig. 6 is used, as described above, the molten salt electrolysis method used in the present invention can be suitably carried out.

Industrial applicability

[0103] According to the production method of the present invention, the molten salt whose Ca concentration has been increased in the electrolysis step is introduced into an adjustment tank equipped with a Ca supply source to make the Ca concentration constant, and then used for the reduction of TiCl. Reduction tank

Four

It is possible to suppress the fluctuation of the Ca concentration of the molten salt introduced into the tank and maintain it at a high concentration. In the electrolysis process, since the molten salt is electrolyzed while flowing in one direction near the surface of the force sword, it is possible to continuously process a large amount of the molten salt. This allows TiCl

The reduction reaction of 4 can be performed efficiently, stable operation is possible, and Ti can be manufactured on an industrial scale. Therefore, the production method of the present invention and the production apparatus of the present invention capable of easily and suitably carrying out this method can be effectively used for the production of Ti by Ca reduction.

Claims

The scope of the claims

[1] By reacting TiCl with Ca in a molten salt containing CaCl and dissolving Ca, the molten salt

twenty four

A reduction process to produce Ti grains inside,

A separation step of separating Ti particles produced in the molten salt from the molten salt;

An electrolysis step of increasing the Ca concentration by electrolyzing a molten salt having a Ca concentration decreased with the formation of Ti grains, and using the main electrolytic cell in the electrolysis step, The molten salt is introduced into a regulating tank having a supply source and brought into contact with the Ca supply source to make the Ca concentration of the molten salt constant, and then used for the reduction of TiCl in the reduction step.

Four

i manufacturing method.

2. The method for producing Ti according to claim 1, wherein the Ca supply source is a molten Ca—Mg alloy.

[3] The Ca concentration in the molten Ca—Mg alloy was measured using a molten salt containing CaCl in an electrolytic cell for the alloy.

2

3. The method for producing Ti according to claim 2, wherein the Ti is increased by understanding.

[4] The molten salt after the Ti grains are separated in the separation step is once charged into the alloy electrolytic cell, and the Ca concentration of the molten salt is reduced and then charged into the main electrolytic cell. The manufacturing method of Ti described in 2.

[5] A method for producing Ti, wherein the adjustment tank used in the method according to claim 1 has a cooling function.

[6] TiC containing CaCl and holding molten salt in which Ca is dissolved and supplied to the molten salt

2

A reduction tank for reacting 1 with the Ca to produce Ti grains;

Four

Separation means for separating molten salt force of Ti particles generated in the molten salt, holding the molten salt after the Ti particles are separated, provided with an anode and a force sword, and having electricity in the molten salt A main electrolytic cell for decomposing and generating Ca on the cathode side;

A Ca supply source is provided, and the molten salt in the main electrolytic cell is introduced and brought into contact with the Ca supply source to make the Ca concentration of the molten salt constant, and then the molten salt is charged into the reduction tank. An apparatus for producing Ti, comprising:

7. The Ti manufacturing apparatus according to claim 6, wherein the Ca supply source is a molten Ca—Mg alloy. 8. The Ti manufacturing apparatus according to claim 7, further comprising an alloy electrolytic cell for increasing the Ca concentration of the molten Ca—Mg alloy.

7. The Ti manufacturing apparatus according to claim 6, wherein the adjustment tank has a cooling function.