JP7229097B2 - Lid for metal reduction reaction vessel and method for producing metal - Google Patents

Description

The present invention proposes a technique related to a lid of a metal reduction reaction vessel used for metal production by contact between a metal chloride and a reducing agent, and a metal production method.

For example, in order to produce sponge titanium by the Kroll method, which is widely used industrially, liquid molten metallic magnesium is stored in advance in a metallic reduction reactor, and titanium tetrachloride is added dropwise onto the molten metallic magnesium. A reduction step is performed. In the reduction step, metallic magnesium acts as a reducing agent to reduce titanium tetrachloride to metallic titanium, and the metallic titanium grows as a sponge titanium mass in the metallic reduction reactor.

After the reduction step, a separation step is generally performed to separate residual metal magnesium and by-product magnesium chloride from the sponge titanium mass generated in the metal reduction reactor. After that, the titanium sponge mass is sorted and crushed to obtain granular titanium sponge.

In the reduction step, the temperature of the metal reduction reaction vessel becomes extremely high due to the heat generated by the reduction reaction between titanium tetrachloride and metallic magnesium. This is particularly a serious problem during high-speed production in which the supply rate of titanium tetrachloride is increased in order to improve the productivity of titanium sponge blocks.
In this regard, Patent Document 1 discloses that "When titanium tetrachloride is dripped from above a molten magnesium metal bath charged into a heated reaction vessel to produce sponge-like titanium metal, air A method for cooling a sponge titanium reduction furnace, characterized by spraying a mixture of water droplets in the form of a mist onto the upper portion of the outer wall of the reaction vessel for cooling.

JP-A-7-41880

By the way, a metal reduction reaction vessel may include a vessel body for storing a reducing agent such as metallic magnesium and a lid body for covering an opening of the vessel body. In the reduction process, not only the container body but also the lid is affected by the heat generated by the reduction reaction. Especially in the middle stage of the reduction process, as shown in FIG. Since the cooling efficiency of the inside decreases and the surface temperature of the molten magnesium metal rises, the bottom wall of the lid is also exposed to high temperatures. Therefore, in order to prevent melting damage and deformation of the lid, it is necessary to effectively dissipate heat from the lid.

However, although techniques for cooling the container body have been developed so far, it is difficult to say that an effective cooling technique for the lid has been established. Japanese Patent Laid-Open No. 2002-200000 also does not describe cooling of the lid.

SUMMARY OF THE INVENTION An object of the present invention is to provide a lid for a metal reduction reaction vessel and a method for producing metal, which can cool the lid satisfactorily.

As a result of intensive studies, the inventors focused on the fact that the portion that is greatly affected by the heat generated by the reduction reaction is the bottom wall of the lid located on the container main body side, and disperses the heat medium toward this bottom wall of the lid. It was found that the lid body can be cooled well by feeding the lid body.

Based on such findings, the lid of the present invention is attached to the main body of a metal reduction reaction vessel used for producing metal by contacting a metal chloride and a reducing agent, and the lid is a cylindrical side wall, a bottom wall provided at an end portion of the side wall on the container body side, and an internal flow path formed inside the lid body through which a heat medium can flow; The flow path has a dispersion path including a plurality of holes facing the bottom wall.

In the lid of this invention, it is preferable that at least some of the plurality of holes are arranged on concentric circles around the center of gravity of the cross section of the cylindrical side wall.

In addition, the lid of the present invention further includes one or more partition walls that divide the interior of the lid into a plurality of spaces separated in the inside and outside direction of the container, and the plurality of spaces are divided in the inside and outside direction of the container. and an inner space adjacent to the bottom wall and an outer space adjacent to the outer side of the inner space in the container inside-outside direction, wherein the partition between the inner space and the outer space includes the A divergence path is preferably provided.

In this case, the lid further includes a partition plate that divides the outer space into a central region and a peripheral region, and has the distribution path on a wall portion of the partition on the central region side, and the peripheral edge of the partition. It is preferable that the wall portion on the side of the region is provided with a through hole for sending a heat medium from the inner space to the peripheral region of the outer space.

Further, in this case, an expansion space provided by expanding a portion of the central region in the circumferential direction in a direction orthogonal to the inside and outside direction of the container is provided with an inlet for allowing the heat medium to flow into the inside of the lid, and the peripheral edge It is preferable that an outflow port through which the heat medium flows out from the inside of the lid body is provided at each of both ends in the circumferential direction of the region separated by the expansion space.

The lid body can further include a heat insulating material arranged outside the plurality of spaces in the container inside-outside direction.

It is preferable that the hole has a circular shape with a diameter of 5 mm to 30 mm in plan view.

A method for producing a metal according to the present invention uses a metal reduction reaction vessel having any one of the above lids and a vessel body.

The metal production method of the present invention includes a reduction step of supplying a metal chloride into the metal reduction reaction vessel and reducing the metal chloride by contact with a reducing agent in the metal reduction reaction vessel. and, in the reducing step, a heat medium can be flowed through the internal flow path of the lid.
In the reduction step, it is preferable to maintain the internal pressure of the metal reduction reactor higher than the pressure of the internal flow path of the lid when the heat medium flows through the internal flow path of the lid.

In the method for producing a metal according to the present invention, the metal chloride may be titanium tetrachloride, the reducing agent may be metallic magnesium, and the metal may be metallic titanium to produce a sponge titanium mass.

According to this invention, the lid can be cooled satisfactorily.

FIG. 2 is a vertical cross-sectional view of a metal reduction reaction vessel and its surrounding reduction furnace, schematically showing a reduction process during production of sponge titanium lumps. FIG. 2(a) is a vertical cross-sectional view including the central axis line of the side wall of the lid, showing the lid according to one embodiment of the present invention, and FIG. It is a cross-sectional view along line B. FIG. FIG. 3 is a partially enlarged cross-sectional view of FIG. 2( a ) showing the flow of a heat medium in the internal flow path of the lid shown in FIG. 2 ; It is a figure which shows the analysis model of a comparative example. FIG. 5 is a vertical cross-sectional view including the central axis of the side wall of the lid, showing the lid of the comparative example. FIG. 4 is a vertical cross-sectional view of a metal reduction reaction vessel showing a titanium sponge mass growing within the container body of the metal reduction reaction vessel in the reduction step.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.
The lid 1 of one embodiment of the present invention can be used by being attached to the opening 23 on the upper side of the container body 22 of the metal reduction reaction container 21 as illustrated in FIG. This metal reduction reaction vessel 21 is placed in a reduction furnace 31 and used in the reduction process.

(Reduction process)
In the reduction step, molten metal magnesium as a reducing material is stored in the container body 22 of the metal reduction reaction container 21 . Then, as indicated by the arrow in FIG. 1, titanium tetrachloride as a metal chloride, which is a raw material, is supplied from the upper side through the raw material supply pipe Tr provided near the center of the lid 1 to the bath surface of the molten magnesium metal. The titanium tetrachloride and metallic magnesium are brought into contact with each other in the container main body 22 by dripping and supplying onto Sb. As a result, titanium tetrachloride is reduced by metallic magnesium based on the reaction of the formula: TiCl ₄ +Mg→Ti+MgCl ₂ , and a sponge titanium mass TS is obtained in the container body 22 as metallic titanium, which is the metal to be manufactured.

Here, magnesium chloride as a by-product settles downward from the bath surface Sb due to its higher specific gravity than metallic magnesium. On the other hand, metallic magnesium in the bath floats toward the bath surface Sb due to its relatively small specific gravity. Due to such a difference in specific gravity between magnesium chloride and metallic magnesium, a bath flow occurs, metallic magnesium is positioned on the bath surface Sb, and the reaction continues between this metallic magnesium and the dropped titanium tetrachloride. A titanium sponge mass TS grows mainly in the bath.

In the middle and final stages of the reduction process, as shown in FIG. 1, the titanium sponge WS formed on the inner wall surface of the vessel grows to a certain extent, resulting in a decrease in cooling efficiency inside the vessel and a rise in the temperature of the bath surface Sb. Rise. As a result, particularly in the middle of the reduction process, the lid body 1 is susceptible to the heat generated by the above reduction reaction of titanium tetrachloride. This is a serious problem because when the supply rate of titanium tetrachloride is increased for the purpose of increasing the amount of sponge titanium mass TS produced per unit time, the temperature of the bath surface Sb rises excessively. can be.
In order to deal with this, in this embodiment, as will be described later, a predetermined internal flow path is provided inside the lid 1, thereby realizing good cooling of the lid 1. FIG.

Titanium tetrachloride (TiCl ₄ ) used in the reduction step can be, for example, liquid titanium tetrachloride (also referred to as “purified titanium tetrachloride”) after being purified in a rectification tower. This purified titanium tetrachloride is obtained, for example, by purifying crude titanium tetrachloride produced by reacting a raw material ore such as titanium ore with a carbon source such as coke and chlorine gas in a rectification tower. Since crude titanium tetrachloride contains other volatile chlorides and the like as impurities, it is purified by continuous distillation in a rectifying column. Thereby, high purity purified titanium tetrachloride with most of such impurities reduced is obtained.
However, titanium tetrachloride is not limited to the above purified titanium tetrachloride as long as it can be used in the reduction step.

Further, the magnesium chloride produced in the reduction step can be decomposed into metallic magnesium and chlorine gas by subjecting it to molten salt electrolysis in an electrolytic cell. The metallic magnesium thus obtained can be used again in the reduction step.

(Lid body)
As shown in FIGS. 2(a) and 2(b), the lid 1 includes a cylindrical or other cylindrical side wall 2 and one end of the side wall 2 on the container body 22 side (lower side in FIG. 2(a)). It comprises a bottom wall 3 provided to seal the part and a top plate 4 covering the other end on the opposite side of the side wall 2 (upper side in FIG. 2(a)). Here, the top plate 4 has a disk shape with a slightly larger diameter than the outer diameter of the side wall 2 . The side wall 2 may have a cylindrical shape with a rectangular or other polygonal cross section, but it is often cylindrical with a circular cross section.

Inside the lid 1, an internal flow path 5 is formed for flowing a heat medium such as a cooling medium made of air, gas, or liquid. Air cooling, in which air is flowed through the internal flow path 5, is preferable, but depending on the situation, it is also possible to flow liquid such as water through the internal flow path 5. FIG. In this example, the heat medium flows inside the internal flow path 5 as indicated by arrows in FIG.

Various shapes are conceivable as the internal flow path for cooling the lid body. is distributed and sent.
By setting the area of the dispersion path Pd to 10% or more of the cross-sectional area of the lid body 1 defined by the side wall 2 (the area of the partition wall 7 in FIG. 2B), the cooling capacity is further improved. The area of the dispersion path Pd may be 30% or less of the cross-sectional area of the lid 1, for example. The area of the dispersion path Pd means the area of the closed space defined by connecting the centers of adjacent holes 6 forming the dispersion path Pd on the most peripheral side with a straight line.
In addition, the total area of the plurality of holes 6 when viewed from above is preferably 0.1% to 1.0% of the cross-sectional area of the lid 1 .

By increasing the area of the dispersion path Pd and the area of the hole 6 to some extent as described above, the relatively low-temperature heat medium supplied to the internal flow path 5 is transferred to the bottom of the lid 1 through the dispersion path Pd. It can be delivered over a large area of the wall 3. As a result, the bottom wall 3, which is located on the side of the container body 22 and tends to become hot during the reduction process, can be cooled well. In addition, in the reduction step, when the sponge titanium mass TS grows to a certain extent and the bath surface Sb approaches the lid 1, or when the supply rate of titanium tetrachloride increases, the temperature of the lid 1 becomes even higher. However, even in this case, it is possible to keep the temperature of the lid 1 low to some extent by the internal flow path 5 described above. The lid 1 can also be effectively used for high-speed production of the titanium sponge mass TS, which increases the production amount (growth amount) of the titanium sponge mass TS per unit time.

Especially in the middle stage of the reduction process, the bath surface Sb rises and the supply rate of titanium tetrachloride is often high, so the lid body 1 may become hot. Even under such circumstances, the lid 1 of this embodiment can be well cooled. In the final stage of the reduction process, the amount of molten magnesium metal may decrease and the supply rate of titanium tetrachloride may also become slow. However, since the distance between the bath surface of the molten metal magnesium (or molten magnesium chloride in some cases) and the lid 1 is short, the lid 1 can reach a high temperature even if the supply rate of titanium tetrachloride is slowed down. Even under such circumstances, the lid 1 of this embodiment can be well cooled.

Further, when the lid body 1 is cooled by flowing the heat medium through the internal flow path 5, the wind velocity of the gaseous heat medium flowing through the internal flow path 5 and the pressure of the internal flow path 5 due to the flow of the heat medium are set respectively. may be required to be less than or equal to the value of By suppressing the wind speed to a certain extent, generation of large vibrations of the plate-like member constituting the lid 1 is suppressed, and damage to the lid 1 can be prevented. In addition, since the pressure in the internal flow path 5 of the lid 1 does not become too high, the internal pressure of the metallic reduction reactor 21 can be easily controlled, and damage to the lid can be prevented. By setting the internal pressure of the metal reduction reaction vessel 21 higher than the pressure of the internal flow path 5, the heat medium can be prevented from flowing into the vessel main body 22 even if the lid 1 is damaged. In this embodiment, by forming the internal flow path 5 having the dispersion path Pd as described above in the lid 1, an increase in the wind speed of the heat medium and a pressure rise in the internal flow path 5 of the lid 1 are suppressed. be able to.
The fact that the lid 1 is well cooled by the internal flow path 5 having such a dispersion path Pd is also based on knowledge obtained from simulation results described later.

As shown in FIG. 2B, the plurality of holes 6 forming the dispersion path Pd are centered on the center of gravity of the cross section of the side wall 2 (a point on the central axis CL in the cylindrical side wall 2 shown). It is preferable to arrange them on a plurality of concentric circles (indicated by broken lines in FIG. 2(b)). Moreover, it is preferable to arrange the raw material supply pipe Tr so as to be surrounded by the plurality of holes 6 . The temperature of the bottom wall 3 is the highest in the vicinity of the raw material supply pipe Tr, and erosion and deformation are likely to occur at this portion. Therefore, a plurality of holes 6 are arranged around the raw material supply pipe Tr to dispersively supply the heat medium like a shower, thereby cooling the lid 1 efficiently. In the illustrated embodiment, a plurality of holes 6 are provided at predetermined intervals on the central axis CL and four concentric circles that are equidistant from each other. . In addition, the holes 6 are not provided at the arrangement positions of the raw material supply pipes Tr on the concentric circles.

As shown in FIG. 2, a partition wall 7 is provided inside the lid 1 to divide the internal flow path 5 into a plurality of spaces S1 and S2 in the container inside-outside direction Da. Although it is possible to provide three or more spaces by providing two or more partitions 7, in this embodiment, one partition 7 allows the internal flow path 5 to be divided into two spaces, one on the upper side and the other on the lower side. That is, it is divided into an inner space S1 and an outer space S2.

In this way, there are a plurality of spaces including the inner space S1 located inside the container in the container in-out direction Da and close to the bottom wall 3 and the outer space S2 adjacent to the outside of the inner space S1 in the container in-out direction Da. In this case, the plurality of holes 6 described above can be provided in the partition wall 7 between the inner space S1 and the outer space S2 close to the bottom wall 3 . By doing so, when the heat medium supplied to the internal flow path 5 flows from the outer space S2 to the inner space S1, the heat medium flows through the plurality of holes 6 into the bottom wall 3 adjacent to the inner space S1. to effectively cool the bottom wall 3. However, if there is a dispersion path for dispersing and sending the heat medium toward the bottom wall 3, the bottom wall can be cooled well, so the partition wall 7 that divides the spaces S1 and S2 is not provided. A lid is also included in the present invention. For example, the partition wall 7 is unnecessary for the internal flow path 5 in which the heat medium is introduced near the center of the bottom wall 3 and then discharged from the side wall 2 to the outside of the lid 1 .

In the embodiment shown in FIG. 2, the outer space S2 of the lid 1 may be provided with a partition plate 8 that divides the outer space S2 into a central region Rc and a peripheral region Re, as shown in FIG. can. The distribution path Pd including a plurality of holes 6 is formed by a wall portion of the partition wall 7 located on the central region Rc side across the partition plate 8 of the outer space S2 (the wall portion of the partition wall 7 on the central region Rc side). It is preferable to provide A low-temperature heat medium is dispersed in the central portion of the bottom wall 3, which tends to reach the highest temperature in the reduction process, by the dispersion path Pd formed by the plurality of holes 6 provided in the wall portion on the central region Rc side of the partition wall 7. This is for cooling this central portion particularly efficiently.

On the other hand, at the wall portion of the partition wall 7 located on the peripheral region Re side across the partition plate 8 of the outer space S2 (the wall portion of the partition wall 7 on the peripheral region Re side), the fuel flowed into the inner space S1 through the dispersion path Pd. Through-holes 9 may be provided to direct the heat transfer medium to the peripheral region Re of the outer space S2. Thereby, the heat medium that has flowed into the inner space S1 can be sent to the outer space S2. For example, as shown in FIG. 2(b), the through hole 9 is formed in a circle centered on the central axis CL (indicated by a broken line in FIG. 2(b)) at a position close to the inner surface of the side wall 2 in the peripheral region Re. ) can be provided at equal intervals.

Then, as shown in FIG. 2(b), a part of the central region Rc in the circumferential direction is expanded in a direction orthogonal to the container inside/outside direction Da (horizontal direction in FIG. 2(b)) and expanded there. A space Se is provided. Here, by providing the expansion space Se, the partition plate 8 has a shape in which two parallel flat plates that partition the expansion space Se are provided in a part of the cylinder in the circumferential direction.
In this expansion space Se of the central region Rc, an inflow port 10 for allowing the heat medium to flow into the interior of the lid body 1 is provided. It is preferable to provide an outlet 11 through which the heat medium flows out from the inside of the lid 1 . As a result, the inlet 10 and the outlet 11 can be arranged at a nearby location, and the inlet 10 and the outlet 11 can be arranged without being restricted by other members such as the heat insulating material 12 described later in terms of the arrangement space. is easier to place.

Each hole 6 forming the dispersion path Pd is preferably circular with a diameter of 5 mm to 30 mm in plan view. Holes 6 having a circular planar shape are preferable because they are relatively easy to drill with a drill or the like. When the diameter of the hole 6 is larger than the upper limit value of the above range, the flow rate of the hole 6 located near the inlet 10 of the heat medium is lower than that of the hole 6 located far from the inlet 10. It is not preferable because it becomes larger than the flow rate and cooling of the bottom wall 3 becomes non-uniform. Also, if the diameter of the hole 6 is less than the lower limit of the above range, the amount of air passing through each hole 6 decreases, so for efficient cooling, more holes 6 are arranged. It is not preferable because it is necessary and the processing load for drilling increases. The area of the previously described dispersion path Pd can be, for example, 0.3 m ² to 1.0 m ² in order to improve the cooling capacity. When the area of the dispersion path Pd is larger than the upper limit of the above range, the flow rate of the hole 6 located near the inlet 10 of the heat medium is higher than the flow rate of the hole 6 located far from the inlet 10. large and may result in uneven cooling of the bottom wall 3 . If the area of the dispersion path Pd is less than the lower limit of the above range, there is a concern that the heat medium will be concentrated in the part where the dispersion path Pd exists, and the cooling of the part of the bottom wall 3 where the dispersion path Pd does not exist will be insufficient. be done.
Moreover, it is preferable that the distance between the centers of adjacent holes 6 on the most peripheral side forming the dispersion path Pd is three times or more the diameter of the holes 6 . When the hole 6 is not circular, the diameter is the diameter of a circle having an area equal to the area of the hole 6 in plan view. If it is less than the lower limit, the flow rate of the hole 6 located near the inlet 10 of the heat medium becomes larger than the flow rate of the hole 6 located far from the inlet 10, and the cooling of the bottom wall 3 becomes inadequate. It is not preferable because it becomes uniform. The distance between the centers of adjacent holes 6 on the most peripheral side forming the dispersion path Pd may be, for example, 20 times or less the diameter of the holes 6 . The holes 6 may be arranged regularly or irregularly in the dispersion path Pd.

By the way, a separation step is generally performed after the reduction step. In the separation step, for example, the metallic reduction reaction vessel 21 is connected to another vessel (not shown) through a communication pipe, and the pressure inside the metallic reduction reaction vessel 21 is reduced to remove metallic magnesium and by-products remaining in the reduction step. The magnesium chloride is transferred to the other container to separate it from the titanium sponge mass TS. At this time, the lid 1 can be provided with a heat insulating material 12 for the purpose of preventing magnesium chloride or the like from solidifying there when passing through the lid 1 . The heat insulating material 12 can be, for example, a heat insulating blanket made of alumina-silica-based ceramic fibers. Other members such as the side wall 2, the bottom wall 3 and the top plate 4 of the lid 1 can be made of, for example, stainless steel or carbon steel (steel with a carbon content of 2% by mass or less). Among them, carbon steel is preferable from the viewpoint of suppressing Ni and Cr contamination.

As shown in FIG. 2(a), such a heat insulating material 12 is preferably arranged outside the plurality of spaces S1 and S2 in the container inside/outside direction Da. In this case, there is an advantage that the bottom wall 3 can be efficiently cooled in the reduction process, and the cooling of the lid body 1 due to the outside air can be satisfactorily suppressed in the separation process. In the illustrated embodiment, the heat insulating material 12 is arranged in substantially the entire area outside the container inside/outside direction Da of the outside space S2 except for the pipelines that become the inflow port 10 and the outflow port 11 .
In addition, although not shown, the lid 1 includes a depressurization pipe for depressurizing the space above the bath surface Sb, which becomes high temperature and high pressure in the reduction process, and a pressure relief pipe inside the container body at the start of the reduction process. A Mg supply pipe that is used to supply Mg or the like and has a connection with a connecting pipe may be provided. These arrangements may be provided in the central region Rc and may even occupy part of the divergence path Pd. The effects of the depressurization pipe and the Mg supply pipe on the cooling performance of the lid 1 can be examined by fluid simulation. Therefore, it is possible to dispose the depressurization pipe and the Mg supply pipe while maintaining good cooling performance of the lid 1 . Further, the lid 1 may be provided with a thermometer 13 such as a thermocouple for measuring the temperature of the bottom surface of the lid in order to check whether the lid 1 is properly cooled.

(Metal manufacturing method)
In the method for producing a metal according to one embodiment, the metal chloride is brought into contact with a reducing agent to reduce the metal chloride to produce the metal. A metallic reduction reaction vessel 21 is used.

More specifically, the metal production method includes a reduction step of supplying a metal chloride into the metal reduction reaction vessel 21 and reducing the metal chloride by contact with a reducing agent in the metal reduction reaction vessel 21. can contain.
Here, when titanium tetrachloride is used as the metal chloride and metallic magnesium is used as the reducing agent, it is possible to produce a sponge titanium mass TS in which metallic titanium is used as the metal. The reduction step in this case is as described above.

Here, it is preferable to flow the heating medium through the internal flow path 5 of the lid 1 in the above reduction step. As described above, by flowing a predetermined heat medium through the internal flow path 5 of the lid 1 having the dispersion path Pd, the lid 1, which may reach a high temperature during the reduction process, can be cooled satisfactorily. As a result, the lid body 1 may be able to withstand high-speed production of the titanium sponge block TS.

When the heat medium is supplied to the internal flow path 5 of the lid 1 and the heat medium flows through the internal flow path 5, the internal pressure of the metal reduction reaction vessel 21 is made lower than the pressure of the internal flow path 5 of the lid 1. is also preferably kept high. As a result, even if the lid 1 is damaged, it is possible to suppress the inflow of the heat medium into the container body 22 and the contamination of the titanium sponge block TS due to it.

After the reduction step, a separation step may be performed to separate metallic magnesium remaining in the reduction step and magnesium chloride as a by-product from the sponge titanium mass TS. Here, the metal reduction reaction vessel 21 is connected to another vessel (not shown) through a communication pipe (not shown), and the inside of the metal reduction reaction vessel 21 is decompressed to volatilize and separate magnesium chloride and the like.

Next, the effect of the lid body of the present invention was confirmed and will be described below. However, the description herein is for illustrative purposes only and is not intended to be limiting.

(simulation)
Numerical simulations were performed for a plurality of analytical models of the lid using thermal fluid analysis software Fluent manufactured by ANSYS. As the analysis conditions, the bottom wall of the lid received radiant heat of 1000° C. as heat input, and the heat was removed by air cooling in the internal flow path of the lid. Regarding the analysis results, the temperature of the bottom wall, especially the central part, should be 800°C or less, the wind speed in the internal flow path should be 20 m/s or less, and the pressure in the internal flow path of the lid should be 2000 Pa or less. was used as a condition for passing.

The analysis model of the example shall be shown in FIG. The area of the dispersion path Pd was 14% of the cross-sectional area of the lid 1 defined by the side wall 2 . The total area of the holes 6 included in the dispersion path Pd was 0.5% of the cross-sectional area of the lid body 1 defined by the side wall 2 . The diameter of each hole 6 was set to 20 mm.
In the analysis model of the comparative example, as shown in FIG. 4, the cover 101 was provided with a partition plate 108 so that the internal flow path 105 forms a simple labyrinth in one space without partition walls. In this analysis model, an inlet 110 and an outlet 111 exist on the right and left sides of FIG. 4, respectively, and air flows from right to left. Although the communicating pipe and the depressurization pipe are omitted in FIG. 2, the analysis model of the comparative example (FIG. 4) is the same.

As a result of the analysis, in the analytical model of the comparative example, the maximum temperature of the bottom wall 103 was 950° C., the maximum wind speed of the internal flow passage 105 was 60 m/s, and the maximum pressure of the internal flow passage 105 was 15000 Pa.
On the other hand, in the analysis model of the example, the maximum temperature of the bottom wall 3 was 800° C., the maximum wind speed in the inner space S1 was 20 m/s, and the maximum pressure in the inner space S1 was 1000 Pa.
In the labyrinth system such as the analysis model of the comparative example, it is considered that the temperature of the air becomes high on the downstream side of the labyrinth, and the cooling there becomes insufficient.

(Test example)
From the results of the above simulation, the effectiveness of the lid 1 as shown in FIG. 2 was confirmed. was tested to perform the reduction step using Lid 201 (Comparative Lid) compared with this, as shown in FIG. 1 and substantially the same configuration. Although the communicating pipe and the depressurizing pipe are omitted here, the communicating pipe and depressurizing pipe as described above are assumed to exist in both the lids of the examples and the comparative examples. In particular, in the example, a simulation result was obtained that the same degree of cooling capacity is maintained even if the communicating pipe and the depressurization pipe are present.

In the test of the reduction process, lid 1 of the example and lid 201 of the comparative example were each attached to the opening of the container main body of the metal reduction reactor placed in a predetermined reduction furnace. Here, titanium tetrachloride was dripped from a raw material supply pipe to bring it into contact with the molten metal magnesium in the container body, thereby causing a reduction reaction.

During the reduction process described above, the temperature of the bottom wall 3, 203 of the lid 1, 201 was measured. From the results, the maximum temperature, minimum temperature and average temperature during the reduction process were obtained. Table 1 shows the results.

As shown in Table 1, when lid 1 of Example was used, compared to lid 201 of Comparative Example, the dropping rate of titanium tetrachloride was increased. It can be seen that both the maximum temperatures are sufficiently lowered. Therefore, it was found that the lid 1 of the example can be well cooled by air cooling using the internal flow path 5 .

Reference Signs List 1, 101, 201 Lid 2, 202 Side wall 3, 103, 203 Bottom wall 4, 204 Top plate 5, 105 Internal channel 6 Hole 7 Partition 8, 108 Partition plate 9 Through hole 10, 110 Inlet 11, 111 Outlet 12, 212 Heat insulating material 21 Metal reduction reaction vessel 22, 122 Vessel main body 23 Opening 31 Reduction furnace Sb Bath surface Tr Raw material supply pipe TS Titanium sponge block WS Titanium sponge formed on wall surface S1 Inner space S2 Outer space CL Center axis line Pd Divergence path Rc Central region Re Peripheral region Se Expansion space Da Container inside/outside direction

Claims (10)

A lid attached to a container body of a metal reduction reaction container used for producing metal by contact between a metal chloride and a reducing agent,
The lid includes a cylindrical side wall, a bottom wall provided at an end of the side wall on the container body side, an internal flow path formed inside the lid and capable of allowing a heat medium to flow , one or more partitions dividing the inside of the lid into a plurality of spaces separated in the container inside-outside direction, wherein the plurality of spaces are located inside the container in the container inside-outside direction and are adjacent to the bottom wall. and an outer space adjacent to the outside of the inner space in the container in-out direction,
The internal flow path has a dispersion path including a plurality of holes facing the bottom wall,
A lid body in which the dispersion path is provided in the partition wall between the inner space and the outer space . 2. The lid according to claim 1, wherein at least part of said plurality of holes are arranged on concentric circles around the center of gravity of the cross section of said tubular side wall. The lid further comprises a partition plate that divides the outer space into a central region and a peripheral region,
A wall portion of the partition wall on the central region side has the dispersion path, and a wall portion of the partition wall on the peripheral region side has a through hole for sending a heat medium from the inner space to the peripheral region of the outer space. The lid according to claim 1 or 2, which is provided. An expansion space formed by expanding a part of the central region in the circumferential direction in a direction orthogonal to the inside-outside direction of the container is provided with an inflow port through which the heat medium flows into the inside of the lid body, and in the circumferential direction of the peripheral region. 4. The lid according to claim 3 , wherein an outlet is provided at each of the two ends separated by the expansion space to allow the heat medium to flow out from the interior of the lid. 5. The lid according to any one of claims 1 to 4 , further comprising a heat insulating material arranged outside the plurality of spaces in the container inside-outside direction. The lid according to any one of claims 1 to 5 , wherein the hole has a circular shape with a diameter of 5 mm to 30 mm in plan view. A method for producing metal, using a metal reduction reaction vessel having the lid according to any one of claims 1 to 6 and a vessel body. A reduction step of supplying a metal chloride into the metal reduction reaction vessel and reducing the metal chloride by contact with a reducing agent in the metal reduction reaction vessel;
8. The method for producing metal according to claim 7 , wherein in said reduction step, a heat medium is caused to flow through said internal flow path of said lid. 9. In the reducing step, when the heating medium flows through the internal flow path of the lid, the internal pressure of the metallic reduction reactor is maintained higher than the pressure of the internal flow path of the lid. A method for producing the metal according to . Titanium tetrachloride is used as the metal chloride, and magnesium metal is used as the reducing agent,
10. The method for producing a metal according to any one of claims 7 to 9 , wherein the metal is a sponge titanium mass, which is titanium metal.

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