JP2005232500A - Method and apparatus for producing sponge titanium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for producing sponge titanium where, at the time of producing sponge titanium by a quantity same as that by the conventional technique, the reduction of the time required for producing the sponge titanium and the quantity of electric power to be used is attained, thus reduction reaction can be efficiently performed. <P>SOLUTION: Regarding the production method, at the time of reducing titanium tetrachloride using magnesium in a reaction vessel, the whole of the outer circumference in the reaction vessel is heated by a reduction furnace, and further, in the reaction vessel, at least the vicinity of the reaction region where magnesium and titanium tetrachloride are contacted is cooled. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for producing sponge titanium, and more particularly to a technique for producing sponge titanium more efficiently than conventional techniques.

  In the case of producing spon titanium by the crawl method, molten magnesium is supplied into the reaction vessel, and then liquid titanium tetrachloride is supplied onto the molten magnesium bath surface to carry out the reduction reaction.

  As the reduction reaction proceeds, sponge titanium is sequentially generated, and the titanium sponge settles and accumulates at the bottom of the reaction vessel, and a part of the titanium deposits and adheres to the inner wall of the reaction vessel. The sponge titanium deposited on the bottom of the reaction vessel grows in the vertical direction as time passes, and merges with the one grown on the inner wall of the reaction vessel in the middle to produce a sponge titanium lump.

  That is, titanium tetrachloride is dropped into the reaction vessel from above, reacts in the vicinity of the bath surface of molten magnesium previously supplied to the reaction vessel, and is reduced to titanium. Titanium grains produced by this reduction reaction coalesce with each other as described above to form a sponge sponge titanium mass.

  In such a reduction reaction, the reaction between titanium tetrachloride and molten magnesium is an exothermic reaction. For this reason, as the reaction proceeds, the temperature in the reaction region and in the vicinity thereof significantly increases. Therefore, generally in the vicinity of the reaction region, the reaction vessel is forcibly cooled by sending air or the like from the outside.

  However, there are cases where air or the like used for cooling the reaction vessel is supplied below the vicinity of the reaction region of the reaction vessel. In such a case, up to the portion of the reaction vessel that should be originally heated. Is not preferable because it is cooled. Further, in the prior art, such forced cooling air or the like is discharged out of the system without being sufficiently utilized, and it has been difficult to efficiently cool the reaction vessel. Therefore, there has been a demand for the development of a method and apparatus that can efficiently cool the vicinity of the reaction region of the reaction vessel.

  As such an apparatus for producing sponge titanium, an apparatus for producing titanium sponge by dripping titanium tetrachloride into molten magnesium is provided with a heating device at the bottom and a partition inside, and the furnace is divided into two parts up and down or There has been proposed an apparatus that is further divided and provided with a gap for cooling or heating between partition walls (see Patent Document 1). Further, as a reduction furnace used in such a manufacturing apparatus, a heat shield plate is provided between adjacent heat generating zones, and the heat effect of the adjacent heat shield plate is prevented by this heat shield plate so as to adjust the temperature of each zone. In addition, there has been proposed a reduction furnace in which the heating value of each heating wire in the intermediate heating zone is smaller than the others (see Patent Document 2).

Japanese Patent Publication No.32-2356 JP 2001-76854 A

  However, in the above-mentioned Patent Documents 1 and 2, there is no description regarding efficient cooling means for the reduction furnace, such as a type in which a cooling zone is provided in a part of the reduction furnace. It cannot be said that the vicinity of the region can be efficiently cooled.

  Therefore, the present invention has been made in view of the above requirements, and in the production process of sponge titanium by the crawl method, in particular, when producing the same amount of sponge titanium as in the prior art, the time required for producing the sponge titanium It aims at providing the manufacturing method and apparatus of sponge titanium which can make a reduction reaction perform efficiently by aiming at shortening of this and reduction of electric power consumption.

  Inventors and others have made extensive studies in view of the above circumstances, and in producing titanium sponge by reducing titanium tetrachloride using magnesium in the reaction vessel, the entire reaction vessel is heated by a reduction furnace. In addition, the present inventors have found that the above-mentioned problem can be effectively solved by cooling the vicinity of a reaction vessel in which titanium tetrachloride and magnesium supplied to the inside of the reaction vessel come into contact with each other and complete the present invention. It came.

  That is, in the method for producing sponge titanium according to the present invention, in producing sponge titanium for reducing titanium tetrachloride using magnesium in the reaction vessel, the entire outer periphery of the reaction vessel is heated by a reduction furnace, and the reaction vessel Among these, at least the vicinity of the reaction region where magnesium and titanium tetrachloride contact is cooled.

  In such a method for producing sponge titanium, a partition plate is provided in a space formed between the reaction vessel and the reduction furnace, and a cooling medium is circulated above the partition plate in the space. It is desirable to make it.

  Next, the sponge titanium production apparatus of the present invention is for suitably carrying out the sponge titanium production method, comprising a reaction vessel and a reduction furnace for heating the entire outer periphery of the reaction vessel, In the reaction vessel, titanium tetrachloride is reduced using magnesium, a partition plate is provided in a space formed between the reaction vessel and the reduction furnace, and the partition plate is located above the partition plate. Further, the present invention is characterized in that a cooling medium introduction port and a discharge port are formed.

  In such a titanium sponge manufacturing apparatus, it is desirable that the partition plate is disposed in the vicinity of the reaction region in the vertical direction, and when a plurality of the partition plates are provided in the vertical direction. More desirable.

  According to the present invention, the part corresponding to the reaction region of the reaction vessel can be efficiently cooled by the production method and apparatus. For this reason, the dropping rate of titanium tetrachloride can be maintained until the end of the reduction reaction without lowering the dropping rate of titanium tetrachloride to the reaction region in the reaction vessel. As a result, in particular, when producing the same amount of sponge titanium as in the prior art, it is possible to shorten the production time of the sponge titanium and reduce the amount of power used, and the sponge titanium can be produced efficiently.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a side view showing an apparatus for producing sponge titanium according to the present invention, in which reference numeral 1 denotes a reduction furnace, 2 denotes a reaction vessel, 3 denotes a vessel lid, 4 denotes a partition plate, 5 denotes a furnace wall, and 6 denotes cooling. A gas inlet, 7 is a cooling gas outlet, and S is a space.

  As shown in FIG. 1, in the titanium sponge production apparatus of the present invention, a reaction vessel 2 is disposed inside a reduction furnace 1, and a vessel lid 3 is attached to the upper portion of the reaction vessel 2. In addition, a space S is formed between the reduction furnace 1 and the reaction vessel 2, and this space S is partitioned up and down by a partition plate 4. Furthermore, two cooling gas inlets 6 and one cooling gas outlet 7 are formed in the furnace wall 5 of the reduction furnace 1 above the partition plate 4 in the vertical direction.

A specific embodiment of the method for producing sponge titanium according to the present invention will be described under the configuration of the apparatus as described above.
First, molten magnesium is supplied to the reaction vessel 2 with the vessel lid 3 removed from the reaction vessel 2. Next, the vessel lid 3 is attached to the reaction vessel 2, titanium chloride is dropped from the titanium chloride supply part 3 a of the vessel lid 3, and titanium tetrachloride is supplied to the reaction vessel 2. At this time, on the molten magnesium bath surface, titanium tetrachloride is reduced by the molten magnesium to produce titanium sponge and magnesium chloride. Since the produced magnesium chloride has a specific gravity greater than that of molten magnesium, it precipitates in the molten magnesium. On the other hand, a part of the generated titanium sponge is deposited on the bottom of the reaction vessel 2 and the other part is deposited on the inner wall of the reaction vessel 2. And both these deposit parts and precipitation parts grow, and when each becomes a fixed magnitude | size, it unites | combines and a sponge titanium lump is produced | generated.

  In addition, the magnesium chloride produced | generated by the said reduction reaction must be extracted outside after production | generation. In this case, for example, argon gas is injected from the inert gas supply 3 b of the container lid 3 to increase the pressure in the reaction container 2, and in this state, magnesium chloride is added to the reaction container 2 from a discharge port (not shown). It is discharged to the outside, and thus to the outside of the reduction furnace 1.

  In carrying out such a series of reduction reactions and the like, it is an object of the present invention to produce sponge titanium more efficiently than in the prior art. In view of such circumstances, in the present invention, the portion of the reaction vessel 2 corresponding to the reaction region of molten magnesium and titanium tetrachloride is efficiently cooled inside the reaction vessel 2. Therefore, for this purpose, a partition plate 4 is provided in the space S formed between the reaction vessel 2 and the reduction furnace 1, and the portion of the reaction vessel 2 corresponding to the reaction region of titanium tetrachloride and magnesium is cooled in a limited manner. I was able to do it. For example, before inserting the reaction vessel 2 into the reduction furnace 1, the partition plate 4 is attached so as to be fitted from the outer periphery to the reaction vessel 2 from the lower side to the upper side in FIG. It is preferable to do. At this time, as shown in the figure, since the reaction vessel 2 is somewhat tapered downward, the reaction vessel 2 and the partition plate 4 are fitted in a certain vertical portion. It is needless to say that such an attachment mode of the partition plate 4 is merely an example of the present invention, and other suitable methods can be adopted.

  As described above, after the reaction vessel 2 and the partition plate 4 are fitted, the reaction vessel 2 with the partition plate 4 is inserted into the reduction furnace 1. For this reason, in the reaction vessel 2, the vicinity of the reaction region located above the partition plate 4 where the molten magnesium and titanium tetrachloride are in contact can be cooled from the outside. On the other hand, the region of the reaction vessel 2 that is located below the partition plate 4 and is to be heated can be suitably heated. Accordingly, the dropping rate of titanium tetrachloride to the reaction region in the reaction vessel 2 can be maintained without being lowered until the end of the reduction reaction. As a result, the production time of sponge titanium can be shortened and the amount of power used can be reduced, and sponge titanium can be produced more efficiently than in the prior art.

  Such a partition plate 4 is preferably provided below the cooling air discharge port 7, and further preferably provided immediately below the cooling air discharge port 7. Thus, by providing the partition plate 4 immediately below the cooling air discharge port 7, it is possible to prevent a temperature drop to the heating zone located below the reaction vessel 2, as well as efficiently in the vicinity of the reaction region. Can be cooled.

  Moreover, the material of the partition plate 4 will not be restrict | limited especially if it can endure the high temperature of 1000 degreeC vicinity, It can comprise with carbon steel etc. which are comparatively easy to obtain. However, if used over a long period of time, there is a risk of corrosion and wear due to the generation of scale, so it is preferable to use stainless steel. Furthermore, the thickness of the partition plate 4 can be appropriately selected in view of the high temperature strength, but is preferably selected in the range of 5 to 20 mm. That is, when the thickness of the partition plate 4 is less than 5 mm, the partition plate 4 may be deformed when used at a high temperature. On the other hand, when the partition plate 4 exceeds 20 mm, not only the cost is increased, but also the weight With the increase, there is a possibility that the fitting between the partition plate 4 and the reaction vessel 2 may be released during use, which is not preferable.

  Furthermore, it is preferable that the inner side of the partition plate 4 is configured to contact the reduction furnace 1 and the reaction vessel 2. With this configuration, the cooling air does not leak from both the gap between the partition plate 4 and the reduction furnace 1 and the gap between the partition plate 4 and the reaction vessel 2. In this case, the temperature drop in the heating zone of the reaction vessel 2 can be prevented, and titanium sponge can be produced efficiently. In addition, although the number of the partition plates 4 may be one, you may provide in multiple places in the perpendicular direction of FIG. By providing the plurality of partition plates 4, it is possible to promote the cooling of the upper part and the lower part of the reaction vessel 2 more efficiently.

  Further, as described above, the magnesium chloride produced as a by-product in the reduction reaction must be periodically extracted to the outside of the reaction vessel 2 in a molten state. For this reason, it is preferable to heat the part below the reaction region above the melting point of magnesium chloride. From this point of view, the partition plate 4 used in the present invention is effective because it can cool the reaction region in a limited manner.

  In addition, the reaction region of molten magnesium and titanium tetrachloride that proceeds in the reaction vessel 2 is not constant from the start to the end of the reduction reaction in the vertical direction shown in FIG. 1 and may vary depending on the operating conditions. In order to flexibly cope with such a situation, it is necessary to be able to change the cooling position accordingly even if the reduction reaction region to be cooled fluctuates. Thus, in order to implement | achieve the aspect which changes a cooling position during operation, for example, the reaction container 2 and the partition plate 4 are not completely fitted, but the partition plate 4 is attached to the reaction container 2 according to the situation. On the other hand, it is desirable to be slidable and to adjust the vertical position of the partition plate 4 steplessly. This aspect can be realized, for example, by making the shape of the reaction vessel 2 into a cylindrical shape instead of the downward tapered shape shown in FIG.

The above is the essence of the titanium sponge production technology of the present invention. Hereinafter, more preferred embodiments will be described.
Although the object of the present invention can be achieved by providing the cooling air inlet 6 at one place, it can also be provided at a plurality of places as shown in FIG. Thus, by providing the plurality of cooling air inlets 6 in the vertical direction, the reaction vessel 2 can be cooled more efficiently.

  Further, by adjusting the amount of air introduced from each cooling air inlet 6, the reaction vessel 2 reaction region can be cooled with high accuracy. Furthermore, the cooling air introduction port 6 and the cooling air discharge port 7 can be provided as a set, and a plurality of them can be provided above the partition plate 4 of the furnace wall 5. By adopting such a structure, the reaction region of the reaction vessel 2 can be efficiently cooled more precisely.

  Furthermore, the cooling air introduced from the cooling air inlet 6 can be supplied so as to be orthogonal to the reaction vessel 2, but may be supplied in a direction oblique to the horizontal direction of FIG. By supplying the cooling air in this way, the cooling air is suitably circulated around the reaction vessel 2, and efficient cooling by the cooling air is realized. The cooling air may be introduced as it is at room temperature, or may be passed through a cooling device in advance. Thus, by preliminarily cooling the cooling air, the reaction vessel 2 can be efficiently cooled. Further, a part of water mist may be mixed in the cooling air. When water mist is mixed, the reaction vessel 2 can be cooled more efficiently.

  Next, the reaction vessel 2 is usually made of carbon steel, but when producing high-purity titanium, it is desirable to make the inside of the reaction vessel 2 clad steel lined with high-purity iron. The heater incorporated in the furnace wall 5 is used to heat the reaction vessel 2 to a temperature range suitable for the reduction reaction. It is preferable that this heater can be divided into block units as much as possible and the temperature can be controlled for each block unit. Furthermore, it is preferable to use a heating element such as a nichrome wire or a Kanthal wire that can withstand long-time heating at a temperature near 1000 ° C. for the heater of the reduction furnace 1.

  The reaction between molten magnesium and titanium tetrachloride performed using the reaction vessel 2 and the reduction furnace 1 is an exothermic reaction. For this reason, when the supply rate of titanium tetrachloride is increased, the temperature of the reaction region increases in the reaction vessel 2. When the temperature of the reaction region of the reaction vessel 2 exceeds 1080 ° C., the titanium metal produced in the reaction vessel 2 and the reaction vessel 2 made of steel or stainless steel form an alloy, and the reaction vessel 2 is melted. There is a risk of causing. For this reason, it is important to control the temperature of the reaction region so as not to exceed the eutectic point (1080 ° C.) of titanium metal and iron. Therefore, it is preferable to control the temperature of the reaction region in the range of 900 to 1050 ° C.

[Experimental Example 1]
Below, the effect of this invention is clarified by the example of this invention and a comparative example.
<Invention Example>
The molten titanium was supplied in advance while forcibly cooling the reaction region of the reaction vessel 2 by supplying cooling air by using the sponge titanium manufacturing apparatus of the present invention provided with the partition plate 4 shown in FIG. Titanium tetrachloride was dropped into the reaction vessel 2 to produce 7t of sponge titanium. As a result, the time required to complete the reduction reaction was 65 hours.

<Comparative example>
In the above embodiment of the present invention, 7 t sponge titanium was produced using the same apparatus except that the partition plate 4 was not provided, and employing the same conditions. As a result, the time required to complete the reduction reaction was 67 hours. In addition, the amount of electric power required to heat the lower part of the reaction vessel 2 was increased by 30% compared to the above-described example of the present invention. Therefore, it was found that by using the apparatus and method of the present invention example, the time required for the reduction reaction can be shortened and the electric power used can be reduced, and as a result, sponge titanium can be produced efficiently. .

  The method and apparatus for producing sponge titanium disclosed in the present invention can be applied to the titanium sponge production technology by the crawl method, and in particular, when producing the same amount of sponge titanium as the prior art, the time required for producing the titanium sponge is shortened. And reduction of power consumption can be aimed at. For this reason, the present invention is useful in various metal-related industries such as titanium refining, which will require further reduction in reduction time and reduction in power consumption.

It is a side view which shows the manufacturing apparatus of sponge titanium of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Reduction furnace 2 ... Reaction container 3 ... Container lid 3a ... Titanium chloride supply part 3b ... Inert gas supply part 4 ... Partition plate 5 ... Furnace wall 6 ... Cooling gas introduction port 7 ... Cooling gas discharge port S ... Space

Claims (5)

  A method for producing titanium sponge that reduces titanium tetrachloride using magnesium in a reaction vessel, wherein the entire outer periphery of the reaction vessel is heated by a reduction furnace, and at least magnesium and titanium tetrachloride in the reaction vessel A method for producing a titanium sponge, characterized in that the vicinity of a reaction region in contact with water is cooled.   The partition plate is provided in a space formed between the reaction vessel and the reduction furnace, and a cooling medium is circulated in an upper part of the space above the partition plate. Method for producing titanium sponge.   A reaction vessel and a reduction furnace that heats the entire outer periphery of the reaction vessel, and in a titanium sponge production apparatus that reduces magnesium tetrachloride using magnesium in the reaction vessel, the reaction vessel and the reduction furnace An apparatus for producing titanium sponge, wherein a partition plate is provided in a space formed therebetween, and an introduction port and a discharge port for a cooling medium are formed above the partition plate in the reduction furnace.   4. The titanium sponge manufacturing apparatus according to claim 3, wherein the partition plate is disposed in the vicinity of the reaction region in the vertical direction.   The apparatus for producing titanium sponge according to claim 3 or 4, wherein a plurality of the partition plates are provided in a vertical direction.

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