JPH0754021A - Method and apparatus for producing titanium powder - Google Patents

Abstract

PURPOSE:To effectively utilize the heat generated in a hydrogenation treatment to the dehydrogenation treatment and embody the running cost reduction, enhancement of the productivity, etc., in production of the titanium powder by a hydrogenation and dehydrogenation method. CONSTITUTION:This method comprises charging feedstock titanium into one chamber of a circular columnar furnace 1 internally bisected to the inside chamber 2 and the outside chamber 3 and titanium hydride powder into the other chamber, carrying out heat transfer between both chambers and subjecting the feedstock titanium to the hydrogenation treatment and the titanium hydride power to the dehydrogenation treatment. The circular columnar furnace 1 is internally bisected to the inside chamber 2 and the outside chamber 3. The outer peripheral part of the outside chamber 3 and the outer peripheral part or central part of the inside chamber 2 are provided with heaters 4, 5. The inside chamber 2 and the outside chamber 3 are respectively provided with discharge pipes 7, 9 and gas introducing pipes 6, 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a pure titanium powder or a titanium alloy powder (herein collectively referred to as titanium powder) as a powder metallurgical raw material by a hydrodehydrogenation method (hereinafter referred to as HDH method). The present invention relates to a method and an apparatus manufactured by.

[0002]

2. Description of the Related Art Titanium alloys have high specific strength, excellent heat resistance and corrosion resistance, and have properties that are extremely effective as materials for aircraft and the like, but hot workability such as melting, forging and rolling and Difficulty in machinability. Therefore, from the viewpoint of reducing the processing cost and improving the yield, the powder metallurgy method is promising as a technique for directly manufacturing a semi-finished product having a final shape. When a titanium alloy is manufactured by powder metallurgy, there are a method of using a mixed powder of pure titanium powder and a powder for adding an alloy element as a raw material, and a method of using a titanium alloy powder.

As a method of producing pure titanium powder, there is a method of directly mechanically crushing titanium sponge into powder, but since titanium sponge is rich in spreadability, it is difficult to pulverize it, and Even if it is produced, it will be of low quality for powder metallurgy due to its high chlorine content. On the other hand, as a method for producing titanium powder, an atomizing method in which a melt of pure titanium or a titanium alloy (hereinafter collectively referred to as titanium) is dispersed by a gas to form powder, or a titanium electrode is rotated and melted by plasma or the like. Then, there is a rotating electrode method in which the powder is dispersed by centrifugal force. According to these methods, a titanium powder having a relatively high purity can be obtained, but there are problems in the shape, particle size, cost, etc. of each powder.

For this reason, titanium is hydrogenated to give a brittle titanium hydride, which is mechanically pulverized into powder and then dehydrogenated by vacuum heating or the like to obtain titanium powder H
The method based on the DH method is generally adopted. In order to obtain a brittle titanium hydride at room temperature by hydrotreating, it is necessary to absorb about 3% by weight or more of hydrogen. A hydride containing about 3% by weight or more of hydrogen is generally called a δ phase. And, it is said that the hydrogenation of titanium is most efficient in the low temperature range of 300 to 500 ° C., but since the surface layer of titanium as a raw material has an oxide layer which serves as a barrier for hydrogen penetration, it is 500 to 600. It is desirable to heat the material at a temperature of not less than 0 ° C. to internally diffuse the oxide layer to render it harmless. Therefore, an efficient operating method is to heat the raw material titanium to 600 to 700 ° C. and then gradually cool it to perform hydrogenation.

The heating for hydrogenation in the conventional HDH method is carried out by placing a container containing titanium as a raw material in a hydrogenation furnace and heating it with a heater provided on the furnace wall.
At this time, the raw material titanium is heated from the outer periphery of the container,
The raw material titanium in the center is gradually heated. Since the hydrogenation of titanium is an exothermic reaction, the temperature rises even after being heated to 600 to 700 ° C, and the raw material titanium is overheated to less than 1000 ° C in the outer peripheral portion of the container and to about 800 ° C in the central portion. It For this reason, there is a problem that wasteful energy is used and it takes a long time to cool, resulting in a decrease in productivity. If the heating temperature is lowered in order to suppress overheating, there is a problem that long-term processing is required and the productivity is also reduced.

On the other hand, dehydrogenation in the conventional HDH method is
Titanium hydride powder was made into a layer thickness of about 30 to 50 mm in a container, which was stacked in multiple stages was placed in a dehydrogenation furnace, which was evacuated to 600 to 700 ° C. by a heater provided on the furnace wall.
It is done by heating to. However, since the dehydrogenation of titanium hydride is an endothermic reaction, it takes time for the temperature of the titanium hydride powder in the center of the furnace to rise, and if the furnace temperature is raised, the dehydrogenated powder may pseudo-sinter. .

[0007]

As described above, the conventional HD
In the H method, the hydrogenation treatment and the dehydrogenation treatment are performed in different furnaces, or even when the same furnace is used, each treatment is performed separately. However, it has the above problems. An object of the present invention is to effectively utilize the heat generated in the hydrotreating process in the dehydrogenation process in the production of titanium powder by the HDH method, and at the same time, reduce the facility cost and improve the productivity.

[0008]

In order to achieve the above object, the present invention has the following structures. That is,
(1) In the HDH method, in a cylindrical furnace in which the inside is divided into an inner chamber and an outer chamber, titanium raw material is charged in one chamber and titanium hydride powder is charged in the other chamber, and heat is applied between both chambers. In the method for producing titanium powder, the raw material titanium is subjected to a hydrogenation treatment and the titanium hydride powder is subjected to a dehydrogenation treatment by moving. Specifically, (2) Titanium raw material is charged into the outer chamber, titanium hydride powder is charged into the inner chamber, heating is started from the outer peripheral portion of the outer chamber, and the heating is performed as the hydrogenation treatment progresses. Then, dehydrogenation treatment may be performed while heating from the outer peripheral portion of the inner chamber, and (3) charging the raw material titanium into the outer chamber and charging the titanium hydride powder into the inner chamber. The heating may be started from the outer peripheral portion of the outer chamber and stopped with the progress of the hydrogenation treatment, and then the dehydrogenation treatment may be performed while heating from the central portion of the inner chamber, and (4) Raw material titanium is charged into the inner chamber, titanium hydride powder is charged into the outer chamber, heating is started from the center of the inner chamber, the heating is stopped as the hydrogenation process progresses, and then the outer chamber is charged. The dehydrogenation treatment may be performed while heating from the outer peripheral portion. (5) And as an apparatus for carrying out the above method, the inside of the cylindrical furnace is divided into an inner chamber and an outer chamber,
A heater is provided in the outer peripheral portion of the outer chamber and the outer peripheral portion of the inner chamber, and an exhaust pipe and a gas introduction pipe are provided in the inner chamber and the outer chamber, respectively, which is a titanium powder manufacturing apparatus, (6) The inside of the cylindrical furnace is divided into an inner chamber and an outer chamber, heaters are provided at the outer peripheral portion of the outer chamber and the central portion of the inner chamber, and an exhaust pipe and a gas are respectively provided in the inner chamber and the outer chamber. The apparatus for producing titanium powder is characterized in that an introduction pipe is provided.

In the present invention, "titanium" is a general term for pure titanium or titanium alloy. That is,
The raw material titanium may be pure titanium or a titanium alloy, pure titanium powder is obtained from the pure titanium raw material, and titanium alloy powder is obtained from the titanium alloy raw material.

[0010]

The present invention will be described in detail below with reference to the drawings. FIG. 1 is a perspective view of a central portion of an apparatus according to claim 5 of the present invention. The inside of the cylindrical furnace 1 is divided into a columnar inner chamber 2 and an annular outer chamber 3, and the inner chamber 2 Inner chamber heater 4 on the outer circumference
However, the outer chamber heater 5 is provided on the outer peripheral portion of the outer chamber 3, and the inner chamber 2 is provided with the inner chamber gas introduction pipe 6 and the inner chamber exhaust pipe 7.
An outer chamber gas introduction pipe 8 and an outer chamber exhaust pipe 9 are provided in the. FIG. 2 is a perspective view of a central portion of a device according to claim 6 of the present invention, which is the same as FIG. 1 except that the inner heater 4 is provided at the center of the inner chamber 2. In the apparatus of FIGS. 1 and 2, the inner chamber gas introduction pipe 6 and the inner chamber exhaust pipe 7, and the outer chamber gas introduction pipe 8 and the outer chamber exhaust pipe 9 are common pipes, and the gas introduction is performed by a valve operation. And exhaust may be switchable, and the device of the present invention includes such a structure. Further, the inner chamber 2 and the outer chamber 3 are structured such that raw material titanium or titanium hydride powder can be loaded and unloaded such that the upper or lower flat plate can be attached and detached. The wall at the boundary between the inner chamber 2 and the outer chamber 3 is preferably made of a material that has heat resistance and airtightness, is less likely to be embrittled by hydrogen, and has good thermal conductivity, such as austenitic stainless steel.

The method of the present invention as defined in claim 1 is based on FIG.
In a cylindrical furnace 1 such as the one described above, raw material titanium was charged into one of the inner chamber 2 and the outer chamber 3, and titanium hydride powder was charged into the other chamber to generate heat generated by hydrogenation of the raw material titanium. Is transferred to the titanium hydride powder to cause heat transfer between the two chambers, so that the raw material titanium is subjected to hydrogenation treatment and the titanium hydride powder is subjected to dehydrogenation treatment. As raw material titanium, sponge titanium, scraps of titanium products or intermediate products, scraps such as scraps, etc. can be applied. The titanium hydride powder is obtained by hydrogenating and pulverizing the above raw material titanium, and the powder is placed in a dish-shaped container and stacked in multiple stages and charged into a furnace.

The concrete method of claim 2 can be carried out by an apparatus as shown in FIG. First, raw material titanium is charged into the outer chamber 3 and titanium hydride powder is charged into the inner chamber 2, and the air in both chambers is exhausted through the inner chamber exhaust pipe 7 and the outer chamber exhaust pipe 9. In the subsequent steps, as shown in FIG. 3, (a) the outer chamber heater 5 is turned on, and hydrogen gas is introduced into the outer chamber 3 through the outer chamber gas introduction pipe 8. The inner chamber 2 is filled with argon gas from the inner chamber gas introduction pipe 6. (B) When the raw material titanium in the outer chamber 3 is heated from the outer periphery and hydrogenation occurs and heat is generated to start hydrogenation, the outer chamber heater 5 is turned off. The titanium hydride powder in the inner chamber 2 is heated by the heat transfer from the outer chamber 3. (C) The raw material titanium in the outer chamber 3 is hydrogenated inward by self-combustion, and the reaction heat heats the titanium hydride powder in the inner chamber 2 to a higher temperature. (D) The inner chamber heater 4 is turned on as necessary to turn on the inner chamber 2
The titanium hydride powder therein is auxiliary heated by the heater 4, and when the titanium hydride powder is heated to a temperature at which it can be dehydrogenated, the inner chamber exhaust pipe 6 evacuates the inner chamber 2 to start dehydrogenation. To be done. (E) The hydrogenation of the raw material titanium in the outer chamber 3 is almost completed, and the temperature starts to drop. The inner heater 4 is turned on,
The dehydrogenation of the titanium hydride powder in the inner chamber 2 progresses more. (F) When the dehydrogenation of the titanium hydride powder in the inner chamber 2 is completed, the inner chamber heater 4 is turned off and the inner chamber gas introduction pipe 6
More argon gas is introduced to start cooling. In the outer chamber 3, at a temperature of 300 ° C. or lower at which hydrogenation hardly occurs, the valve (not shown) of the outer chamber gas introduction pipe 8 is switched to introduce the argon gas to promote cooling. In the steps (a), (b) and (c), the inside of the inner chamber 2 may be evacuated and evacuated, but it is better to fill it with argon gas as described above because the thermal efficiency is better. It is preferable because it is easily heated.

The concrete method of claim 3 can be carried out by an apparatus as shown in FIG. First, raw material titanium is charged in the outer chamber 3, titanium hydride powder is charged in the inner chamber 2, and the inner chamber exhaust pipe 7 is charged.
The air in both chambers is exhausted through the outer chamber exhaust pipe 9. The subsequent steps are the same as in the case of claim 2 above,
In (d) and (e), the titanium hydride powder in the inner chamber 2 is heated by the inner chamber heater 4 provided at the center,
More effectively heated. Further, in (f), the heat of the titanium powder in the inner chamber 2 easily escapes to the outer chamber 3. Therefore, the total processing time is shorter than the method of claim 2.

The concrete method of claim 4 can be carried out by an apparatus as shown in FIG. First, raw material titanium is charged into the inner chamber 2 and titanium hydride powder is charged into the outer chamber 3, and the air in both chambers is exhausted through the inner chamber exhaust pipe 7 and the outer chamber exhaust pipe 9. In the subsequent steps, as shown in FIG. 4, (a) the inner chamber heater 4 is turned on and hydrogen gas is introduced into the inner chamber 2 through the inner chamber gas introduction pipe 6. The outer chamber 3 is filled with argon gas from the outer chamber gas introduction pipe 8 and the outer chamber heater 5 is turned on. (B) When the raw material titanium in the inner chamber 2 is heated from the center and hydrogenation occurs and heat is generated to start hydrogenation, the inner chamber heater 4 is turned off. The titanium hydride powder in the outer chamber 3 is heated by heat transfer from the outer heater 5 and the inner chamber 2. (C) The raw material titanium in the inner chamber 2 is self-combusted to hydrogenate outward, and the heat of reaction heats the titanium hydride powder in the outer chamber 3 to a higher temperature. When the titanium hydride powder is heated to a temperature at which it can be dehydrogenated, the inside of the outer chamber 3 is evacuated from the outer chamber exhaust pipe 9, and the dehydrogenation of the titanium hydride powder is started. (D) Hydrogenation of the raw material titanium in the inner chamber 2 is almost completed, and the temperature starts to drop. In the outer chamber 3, dehydrogenation of titanium hydride powder is progressing. (E) After the dehydrogenation in the outer chamber 3 is completed, the outer chamber heater 5 is turned off, and argon gas is introduced from the outer chamber gas introduction pipe 8 to start cooling the titanium powder. In the inner chamber 2, cooling is progressing from the center toward the outside. (F) The temperature in the inner chamber 2 hardly causes hydrogenation 3
When the temperature falls below 00 ° C., the valve (not shown) of the inner chamber gas introduction pipe 6 is switched to introduce argon gas to promote cooling. In the steps (a) and (b), the inside of the outer chamber 3 may be evacuated and evacuated, but if the argon gas is filled as described above, the thermal efficiency is higher and the heating is easier. Therefore, it is preferable.

[0015]

【Example】

(Invention Example 1) As shown in FIG. 5, raw material titanium 12 made of various types of commercial pure titanium scrap is charged into the outer chamber 3, and titanium hydride powder 13 made of commercial pure titanium is placed in the dish-shaped container 11. The materials put in the above were placed in the inner chamber 2 in a stacked manner, and processed by the process shown in FIG. The dish-shaped container 11 containing the titanium hydride powder 13 is in the shape of a donut with an empty central portion, has notches 14 on the inner and outer edges, and has an inner chamber gas introduction pipe 6 in the empty portion. Threaded as shown. A plurality of openings 15 are provided in the inner chamber gas introduction pipe 6, and an argon gas for cooling was introduced from the openings 15 through the notches 14 on the inner circumference of the dish-shaped container 11. The processing amount is 200 kg for both the raw material titanium 12 and the titanium hydride powder 13.
Is.

(Invention Example 2) In FIG. 5, the inner chamber heater 4 was coiled around the inner chamber gas introduction pipe 6 and treated in the same manner as in the first invention example. (Invention Example 3) As shown in FIG. 6, the same raw material titanium 12 as in Invention Example 1 was charged into the inner chamber 2, and the titanium hydride powder 13 similar to that of Invention Example 1 was placed in the outer chamber 3. What was put in the cylindrical container 11 was stacked and loaded, and processed by the process shown in FIG. The dish-shaped container 11 is fan-shaped, has a notch 14 at the edge thereof, is arranged in the circumferential direction of the outer chamber 3, and is provided with the outer chamber gas introduction pipe 8 at the boundary as shown in the drawing. Argon gas for cooling was introduced through the notches 14 from the openings 15 provided in the outer chamber gas introduction pipe 8 in multiple stages. Raw material titanium 12 and titanium hydride powder 1
The processing amount of No. 3 is the same as that of the first example of the present invention.

(Prior art example) Raw material titanium and titanium hydride powder of the same weight as the present invention example were treated in a single processing furnace.
Under the same conditions as in Inventive Example 1, hydrogenation and dehydrogenation treatments were separately performed. In each of the above examples, the hydrogenation treatment has a hydrogen content of 3.8%,
Table 1 shows the results of comparison of the processing time and the power consumption for the dehydrogenation treatment up to a hydrogen content of 200 ppm. As is clear from the above, the present invention has been found to have a remarkable effect in shortening the processing time and saving power. Also, when titanium alloy (Ti-6Al-4V) scraps of various forms were used as raw material titanium, the same effect as above was obtained.

[0018]

[Table 1]

[0019]

According to the present invention, in the production of titanium powder by the hydrodehydrogenation method, the hydrogenation and dehydrogenation of titanium are simultaneously carried out in an integrated furnace, and the hydrotreatment is carried out. The heat generated in the process is effectively used for the dehydrogenation process.
That is, in the chamber adjacent to the chamber where the hydrogenation treatment of titanium which is an exothermic reaction proceeds, the reaction heat is received, the dehydrogenation treatment which is an endothermic reaction is efficiently performed, and the cooling after the hydrogenation treatment is performed. Efficiently done by removing heat. As a result, a significant reduction in energy consumption and equipment costs and a significant increase in productivity are achieved.

[Brief description of drawings]

FIG. 1 is a cross-sectional perspective view of a central portion showing an example of the device of the present invention.

FIG. 2 is a perspective view of a cross section of a central portion showing another example of the device of the present invention.

FIG. 3 is an explanatory diagram showing an example of steps of the method of the present invention.

FIG. 4 is an explanatory view showing another example of steps of the method of the present invention.

FIG. 5 is a central cross-sectional perspective view showing an embodiment of the present invention.

FIG. 6 is a cross-sectional perspective view of a central portion of another embodiment of the present invention.

[Explanation of symbols]

 1: Cylindrical furnace 2: Inner chamber 3: Outer chamber 4: Inner chamber heater 5: Outer chamber heater 6: Inner chamber gas introduction pipe 7: Inner chamber exhaust pipe 8: Outer chamber gas introduction pipe 9: Outer chamber exhaust pipe 10 : Valve 11: Dish-shaped container 12: Raw material titanium 13: Titanium hydride powder 14: Notch 15: Opening

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masao Yamamiya 2-6-3 Otemachi, Chiyoda-ku, Tokyo Within Nippon Steel Corporation (72) Inventor Michio Tamura 1 Fuji-machi, Hirohata-ku, Himeji-shi, Hyogo New Nippon Steel Co., Ltd. Hirohata Works (72) Inventor Wataru Kagohashi 3-3-5 Chigasaki, Chigasaki City, Kanagawa Prefecture Toho Titanium Co., Ltd. (72) Ryoji Murayama 3-3-5 Chigasaki, Chigasaki City, Kanagawa Prefecture Titanium Co., Ltd. (72) Inventor Eiichi Fukasawa 3-3-5 Chigasaki, Chigasaki City, Kanagawa Toho Titanium Co., Ltd.

Claims (6)

[Claims] 1. A method for producing titanium powder by a hydrodehydrogenation method, wherein in a cylindrical furnace whose inside is divided into an inner chamber and an outer chamber, titanium is used as a raw material in one chamber and hydrogenated in the other chamber. A method for producing titanium powder, characterized in that titanium powder is charged, heat is transferred between both chambers, and the raw material titanium is subjected to hydrogenation treatment and the titanium hydride powder is subjected to dehydrogenation treatment. 2. A raw material titanium is charged into the outer chamber, titanium hydride powder is charged into the inner chamber, heating is started from the outer peripheral portion of the outer chamber, and the heating is stopped as the hydrogenation process progresses. The method for producing titanium powder according to claim 1, wherein the dehydrogenation treatment is then performed while heating from the outer peripheral portion of the inner chamber. 3. A raw material titanium is charged into the outer chamber, titanium hydride powder is charged into the inner chamber, heating is started from the outer peripheral portion of the outer chamber, and the heating is stopped as the hydrogenation process progresses. Then, the method for producing titanium powder according to claim 1, wherein the dehydrogenation treatment is performed while heating from the center of the inner chamber. 4. A raw material titanium is charged into the inner chamber, titanium hydride powder is charged into the outer chamber, heating is started from the center of the inner chamber, and the heating is stopped as the hydrogenation process progresses. The method for producing titanium powder according to claim 1, wherein the dehydrogenation treatment is then performed while heating the outer peripheral portion of the outer chamber. 5. A cylindrical furnace is divided into an inner chamber and an outer chamber into two parts, a heater is provided at an outer peripheral portion of the outer chamber and an outer peripheral portion of the inner chamber, and an exhaust pipe and an outer pipe are provided in the inner chamber and the outer chamber, respectively. An apparatus for producing titanium powder, characterized in that a gas introduction pipe is provided. 6. The inside of a cylindrical furnace is divided into an inner chamber and an outer chamber, heaters are provided at an outer peripheral portion of the outer chamber and a central portion of the inner chamber, and an exhaust pipe and an outer chamber are provided in the inner chamber and the outer chamber, respectively. An apparatus for producing titanium powder, characterized in that a gas introduction pipe is provided.