JP4673337B2 - Method for producing sponge titanium - Google Patents

Description

  The present invention relates to a method for producing sponge titanium by a crawl method, and more particularly to a method by which the produced sponge titanium can be efficiently extracted from a reaction vessel.

  As for titanium metal, demand for civilian use has increased significantly in recent years as well as in the aircraft industry, and expectation for supply of sponge titanium as a raw material has also increased.

  The sponge titanium is produced by a so-called crawl method. The crawl method is a method in which titanium tetrachloride is dropped onto a molten magnesium bath surface charged and held in a stainless steel reaction vessel to produce sponge titanium in the reaction vessel.

  By heating the sponge titanium produced in the reaction vessel at a high temperature under reduced pressure, magnesium chloride and metal magnesium remaining in the sponge titanium are separated, and a sponge titanium mass as a product is obtained.

  FIG. 7 shows a state of the titanium sponge block 20 generated in the reaction vessel 1. The sponge titanium mass 20 generated in the reaction vessel is cut into the cap portion 10 provided at the bottom of the reaction vessel to form an opening at the bottom of the reaction vessel, and then a push-out rod is inserted through the opening to put the inside of the reaction vessel. The sponge titanium lump produced in the above is pressed, pushed out of the reaction vessel, and then crushed and sized to obtain granular product sponge titanium (see, for example, Patent Document 1).

  The cutting of the cap part 10 here means cutting and separating the cap part side body part 10A out of the cap part side body part 10A and the cap part bottom part 10B constituting the cap part 10 as shown in FIG. Means. Further, the cut and separated cap portion means a cut and separated cap side body portion 10C to which the cap bottom portion 10B is welded in FIG.

  FIG. 4 shows a state in which a sponge titanium lump 20 produced in the reaction vessel 1 is pushed out in a conventional sponge titanium production apparatus. A punching jig 4 is disposed at the bottom of the reaction vessel 1. The punching jig 4 has a function of dispersing and applying the stress of the punching bar 5 inserted through the opening 11 provided at the bottom of the reaction vessel 1 to the sponge titanium mass 20. Along with the insertion movement of the punch bar 5, the sponge titanium lump 20 can be pushed out of the reaction vessel 1. However, when the punching of the sponge titanium lump 20 from the reaction vessel 1 is completed, the punching jig 4 and the bottom of the sponge titanium lump 20 are fixed to each other, and only the punching jig 4 is removed from the sponge titanium lump 20. Separation may not be easy, and improvement has been demanded.

  Further, the opening provided in the bottom of the reaction vessel is subjected to the next manufacturing process of the titanium sponge by welding the cap portion 10C cut and separated into the opening after the completion of the punching out of the titanium sponge. . However, the deterioration of the welded portion that is repeated in the cut portion of the cap-side body portion 10A is inevitable, and improvement has been demanded.

As described above, the sponge titanium mass generated in the reaction vessel is efficiently extracted, and after the sponge titanium mass is pushed out, the cap portion 10C cut and separated into the opening is welded. There is a demand for a method that can efficiently improve the number of times it can be reused.
JP-A-6-145825

  The present invention is a method for producing titanium sponge by the crawl method, and in particular, it is possible to shorten the time for collecting the titanium sponge after the sponge titanium is extracted by more easily extracting the sponge titanium mass produced in the reaction vessel. And it aims at provision of the method of reducing deterioration of reaction container and reusing more times.

  In the process of producing sponge titanium by magnesium reduction of titanium tetrachloride, an extensive study has been conducted in view of such circumstances, and a sponge titanium punching jig is disposed at the bottom of the reaction vessel, and the punching is further performed. By placing a floor plate on the jig and generating sponge titanium on the floor plate, it is possible to easily avoid sticking of the sponge titanium mass after being punched out of the reaction vessel and the punching jig, As a result, it was found that only the titanium sponge lump can be efficiently recovered, and the present invention has been completed.

That is, the present invention is a method for producing sponge titanium by magnesium reduction of titanium tetrachloride, wherein a part of the bottom part is a convex part protruding downward from the bottom part and constitutes a cap part having a cylindrical side body part. A punching jig is provided at the bottom of the reaction vessel, and a floor plate that can easily separate the sponge titanium mass from the punching jig is provided on the punching jig. After titanium chloride is dropped to form a titanium sponge lump, the cylindrical side barrel of the cap part is cut to form an opening at the bottom of the reaction vessel, and a punching rod is inserted into the opening to prevent punching. The titanium sponge lump is extracted from the reaction vessel by pressing the tool.

  Moreover, this invention makes it a preferable aspect to interpose a ceramic layer or a sponge titanium layer between the said punching jig and a flooring board.

  Furthermore, when cutting the cap portion, it is preferable to form a welding groove at a location where the reaction vessel and the cap portion are welded, and then perform diameter expansion drilling.

  By producing sponge titanium according to the present invention described above, the sponge titanium mass produced in the reaction vessel is generated on the floor plate, so that the sponge titanium is prevented from sticking to the punching jig, Can be efficiently punched out, and as a result, the recovery time of sponge titanium can be shortened. In addition, deterioration due to repeated welding of the reaction vessel and the cap portion is suppressed, and the service life of the reaction vessel can be improved.

  The best embodiment of the present invention will be described below with reference to the drawings. FIG. 1 and FIG. 2 show a preferred apparatus configuration example for carrying out the present invention, and a preferred embodiment of the present invention will be described below with reference to FIG.

  FIG. 1 shows the inside of the reaction vessel 1 before the reaction in the apparatus for producing sponge titanium according to this embodiment. At the bottom of the reaction vessel 1, a punching jig 4 used for punching of the sponge titanium to be produced later is disposed, and a floor plate 3 is disposed on the punching jig 4, and the molten magnesium 2 is placed from above. A fixed amount has been injected.

  The punching jig 4 is preferably hollow inside and provided with a plurality of through holes on the surface. With such a configuration, magnesium chloride produced as a by-product along with sponge titanium in the upper space of the punching jig 4 can be collected in the lower part of the reaction vessel 1 and can be efficiently extracted to the outside. Is.

  A pipe (not shown) extending in the vertical direction is connected to the bottom of the reaction vessel 1, and magnesium chloride by-produced in the reaction vessel 1 can be efficiently extracted out of the system through the pipe.

  The floor plate 3, the punching jig 4, and the reaction vessel 1 are in contact with the molten magnesium 2 and are left standing until the temperature is stabilized in the above state. Therefore, when manufacturing high purity sponge titanium that dislikes contamination of nickel and chromium, it is preferable that the floor plate 3, the punching jig 4 and the reaction vessel 1 are made of a material having a low content of nickel or chromium. As a result, it is possible to effectively suppress the elution amount of nickel and chromium from the floor plate 3, the punching jig 4 or the reaction vessel 1 to the molten magnesium 2.

  Therefore, in the present invention, the floor plate 3, the punching jig 4 and the reaction vessel 1 are preferably made of carbon steel, and in particular, carbon steel having a nickel content of 200 ppm or less is preferably used as the material. There is no standard for nickel and chromium in commercially available carbon steel, but steel materials having a low content of nickel or chromium can be selected and used by obtaining analytical values in advance.

  On the other hand, it is preferable to use a nickel or chromium content in molten magnesium 2 that is as low as possible. Specifically, the nickel content is preferably 1 ppm or less, and more preferably 0.5 ppm or less. . The molten magnesium 2 having a low nickel content is produced by specially selecting and using a material for transporting, holding, or electrolyzing magnesium chloride as a raw material. be able to.

  In the present invention, a ceramic layer may be interposed between the floor plate 3 and the punching jig 4 in advance. The ceramic layer is preferably composed of titanium oxide, and in particular, it is preferable to place the covering plate 3 after the massive titanium oxide is spread on the surface of the punching jig 4.

  In addition, the titanium oxide may be a mass of titanium oxide obtained by press-molding fine titanium oxide and calcined at a high temperature, and may be interposed between the punching jig 4 and the floor plate 3. The massive titanium oxide is preferably configured to have the same size as the thickness of the floor plate 3. By interposing the massive titanium oxide having the above-described size between the base plate 3 and the punching jig 4, the base plate 3 may develop while being exposed to a high-temperature molten salt during the reduction reaction. And the punching jig 4 can be effectively prevented from sticking.

  Furthermore, in the present invention, instead of the ceramic layer, sponge titanium may be laid. Sponge titanium is less likely to cause oxygen contamination of the sponge titanium produced on the floor plate 3 than the ceramic layer, and can be suitably used for producing high-purity sponge titanium.

  The sponge titanium is preferably high-purity titanium with few impurities. Among them, it is preferable to use sponge titanium having a nickel content of 10 ppm or less, and further 5 ppm or less.

  It is preferable that a gap is provided between the floor plate 3 and the reaction vessel 1 so that molten magnesium chloride can be easily circulated. Therefore, it is preferable that the diameter of the floor plate 3 according to the present invention is made in the range of 80% to 90% with respect to the inner diameter of the reaction vessel 1.

  The surface shape of the punching jig 4 arranged in close contact with the floor plate 3 according to the present invention is not necessarily a flat surface, and may be a shape bulging upward as shown in FIG. The shape of the punching jig 4 may change naturally as the number of uses increases. When such deformation shown in this embodiment proceeds, the contact area with the floor plate 3 is reduced as compared with the case where the surface is a flat plate, and the fixation between the floor plate 3 and the punching jig 4 is effectively avoided. .

  However, since the stability of the floor plate 3 is lacking, it is possible to stably arrange the floor plate 3 on the punching jig 4 by interposing a ring-shaped or block-shaped piece 6 as shown in FIG. it can.

  Thus, in this invention, it can be said that the surface shape of the punching jig | tool 4 which touches the flooring board 3 is one of the preferable aspects also in an upward convex shape.

  After configuring the apparatus as described above, a predetermined amount of molten magnesium 2 is injected into the reaction vessel 1, and then titanium tetrachloride is introduced into the reaction vessel 1 from a titanium tetrachloride supply pipe 12 disposed at the top of the reaction vessel 1. Start dripping.

  When the dropping of titanium tetrachloride is started, a reduction reaction occurs near the bath surface of molten magnesium 2 to produce titanium sponge and by-produce magnesium chloride. In the vicinity of the bath surface, granular or lump-like sponge titanium is formed and settled and deposited in the molten magnesium 2 to form a sponge titanium lump 20.

  On the other hand, magnesium chloride by-produced in the reduction reaction is appropriately discharged out of the system via a pipe (not shown) attached to the reaction vessel 1.

  Therefore, at the end of the above-described reduction reaction, a sponge titanium lump 20 containing magnesium chloride or metal magnesium is generated. The magnesium chloride and metal magnesium can be efficiently separated and removed from the sponge titanium 20 by heating to high temperature under reduced pressure. As a result, a highly pure sponge titanium 20 can be produced.

  FIG. 2 shows a state of the titanium sponge lump 20 generated in the reaction vessel 1 by the separation operation. The sponge titanium lump 20 is generated on the punching jig 4 through the floor plate 3. Further, the sponge titanium block 20 is often in close contact with the side wall of the reaction vessel 1.

  In order to insert the punch bar 5 as shown in FIG. 3 by cutting the welded portion 15 formed on the side body 10A of the cap 10 provided at the bottom of the reaction vessel 1 in the state of FIG. The opening 11 can be formed.

  In the present invention, when the cap 10 for reopening the bottom of the reaction vessel 1 is cut, a V-shaped groove is first formed in the welded portion 15 as shown in FIG. Then, it is preferable that the V-shaped tip is subjected to diameter expansion drilling with a blade having a flat tip.

  By cutting the welded portion 15 of the cap 10 in such a procedure and then expanding the diameter, the welded portion 15 in which the remarkable deterioration remaining in the reaction vessel 1 is observed and the welded portion 15 of the cap 10 are removed together. be able to. The already-welded part here means the vicinity of the welded part 15 and means a part that is affected by heat during past welding. Specifically, it means a range of 10 to 50% with respect to the vertical width of the welded portion 15. As a result, in the next welding, as shown in FIG. 6 (c), it is possible to weld new material parts that have not been deteriorated by welding, so that the strength after welding is kept healthy. It has the effect of being able to do it.

  In addition, since the reaction vessel 1 and a part of the cap 10 are cut together with the cut of the welded portion 15, both are shortened each time welding and cutting are repeated. The material loss at the boundary with the cap 10 is small, and 20-30 batches of sponge titanium can be produced before the new cap 10 reaches the end of its life.

  After the opening 11 is formed at the bottom of the reaction vessel 1 according to the above procedure, the punching bar 5 is inserted through the opening 11 and brought into contact with the punching jig 4, and then the lower part of the punching bar 5. By actuating a hydraulic cylinder (not shown) engaged with the slab, stress can be applied to the sponge titanium mass via the floor plate 3 placed on the punching jig 4.

  The sponge titanium mass 20 to which the stress is applied can gradually slide in the reaction vessel 1 to push out the entire sponge titanium mass 20 from the reaction vessel 1. When the punching jig 4 arranged at the bottom of the titanium sponge lump 20 appeared at the top of the reaction vessel 1, the punching jig 4 was separated and removed from the sponge titanium lump 20, and then separated from the punching jig 4. By separating and removing the bottom plate 3 that is in close contact with the bottom of the sponge titanium lump 20, the sponge titanium lump 20 can be recovered.

  The present invention is characterized in that the floor plate 3 is placed on top of the punching jig 4. For this reason, the sponge titanium lump 2 can be easily separated from the punching jig 4 through the floor plate 3.

  The floor plate 3 is preferably constituted by a flat plate having no through holes. Moreover, it is preferable to comprise flat carbon steel having a slightly smaller diameter than the inner diameter of the reaction vessel 1. By constituting the floor plate 3 with a flat plate, the adhesiveness between the sponge titanium lump 2 and the floor plate can be lowered, and as a result, the effect that the floor plate 3 can be separated from the sponge titanium lump relatively easily. It is what you play.

  Considering the extraction of magnesium chloride performed during the titanium sponge production reaction shown in FIG. 1, it seems that the base plate 3 is preferably not a flat plate but a through hole. However, if there is a through hole in the floor plate 3, sponge titanium is generated up to the inside of the through hole, and as a result, the floor plate 3 may not be separated from the sponge titanium lump 20. Therefore, in this invention, it is preferable to comprise the flooring board 3 by what is called a flat plate without the hole.

  The floor plate 3 is preferably made of carbon steel, and it is preferable to select and use carbon steel having low nickel among the carbon steels. In this invention, it is preferable that the nickel content rate in the said carbon steel is 200 ppm or less. By prescribing the nickel content in the above range, nickel contamination to the sponge titanium produced on the floor plate 3 can be suppressed, and as a result, the yield in the case of producing high-purity titanium is greatly improved. Can contribute.

  The sponge titanium lump 20 from which the floor plate 3 has been separated and removed can be obtained by removing the surface layer portion where the impurities are concentrated, and then crushing and sizing, thereby obtaining product sponge titanium.

  Since the bottom part of the sponge titanium lump 20 extracted from the reaction vessel 1 was in close contact with the floor plate 3 made of carbon steel, iron contamination was remarkable. Therefore, it is preferable to cut and remove the bottom of the sponge titanium lump 20 in advance prior to the crushing / sizing step.

  The thickness of the bottom of the sponge titanium lump 20 by cutting and removing can be roughly specified with reference to the color of titanium sponge and the analysis value. In the present invention, a range of 1/15 to 1/20 of the entire length of the sponge titanium lump 20 is a preferable range of the thickness of the sponge titanium lump that is cut and removed.

  The surface layer portion of the sponge titanium lump 20 produced by the above-described method is contaminated with iron. This can be achieved by separating the chip or the outer peripheral portion of the sponge titanium lump prior to crushing and sizing. Sponge titanium with less contamination can be recovered.

  In addition, sponge titanium is often deposited on the surfaces of the punching jig 4 and the floor board 3 that have been immersed in molten magnesium. Since the punching jig 4 and the floor plate 3 are disposed at the bottom of the reaction vessel and are in a position where impurities are easily concentrated, it is preferable that the sponge titanium adhering layer is completely scraped off.

  After the sponge titanium block 20 is taken out by inserting the punch bar 5, as shown in FIG. 6C, the reaction vessel 1 and the cut and separated cap portion 10C are brought into contact with each other and welded. Used for the production of sponge titanium.

  By following the above-described invention of the present application, it is possible to produce not only iron but also sponge titanium having low nickel and chromium. As a result, it is possible to produce sponge titanium having a high purity such as 4N5 or 5N.

1. Apparatus configuration 1) Reaction vessel Size: Diameter 1900 mm x Total length 5360 mm
Wall structure: Stainless clad steel lined with carbon steel on the inner surface (nickel content in carbon steel: 200 ppm)
2) Floor board Size: Diameter 1700mm x Thickness 32mm
Material: Carbon steel (Nickel content: 200ppm)
Remarks: Flat plate without through hole 3) Punching jig Size: Diameter 1500mm x Thickness 590mm
Material: Carbon steel (Nickel content: 200ppm)
Remarks: The inside is a hollow block shape, and a plurality of magnesium chloride outlets are formed on the surface.
4) Intervening layer between floor plate and punching jig Bulk titanium oxide: 4N grade titanium oxide is fired at a high temperature to use 10-30 mm fired pellets.
Sponge titanium: 4N grade sponge titanium sized to 10-30mm

2. Raw material 1) Titanium tetrachloride: purity 4N
2) Magnesium: nickel content: 0.5 ppm

[Example 1]
As shown in FIG. 2, a sponge titanium lump 20 was produced in the reaction vessel 1, and the generated sponge titanium lump 20 was extracted out of the reaction vessel 1 as shown in FIG. 3. The punching jig 4 was separated from the sponge titanium lump 20 drawn out of the reaction vessel 1, and the sponge titanium lump 20 was recovered. Subsequently, the bottom plate 3 disposed on the bottom of the sponge titanium lump 20 was peeled and removed to recover only the sponge titanium lump 20.
Thirty batches of sponge titanium were produced under the above conditions, but the punching jig 4 did not come into close contact with the sponge titanium lump 20 and did not fall into a difficult situation.

[Comparative Example 1]
A sponge titanium lump was produced 10 times under the same conditions as in Example 1 except that the floorboard was not used.
At that stage, the punching jig was in close contact with the bottom of the sponge titanium lump, and time was taken to recover only the punching jig 4. Inevitably, the bottom of the titanium sponge lump 2 to which the punching jig 4 was fixed was pulverized to recover the punching jig 4.

[Example 2]
As shown in FIG. 6, after forming a V-shaped groove in the welded portion 15, a thickness corresponding to 10% of the maximum width of the groove (the groove width formed on the outer surface of the cap portion 1). The tip of the groove was subjected to diameter expansion drilling with a cutter having Next, after pressing the sponge titanium lump, the opening was welded and joined to produce 20 batches of sponge titanium, but no cracks or the like were found in the weld.

[Comparative Example 2]
In Example 2, after forming the V-shaped groove, the expanded titanium punch was pushed through without expanding the diameter, and the opening was welded and joined. When 11 batches of sponge titanium were produced by such an operation, cracks were observed in the welded portion, and deterioration of the surrounding structure was also observed. Therefore, the cap 10 provided at the bottom of the reaction vessel 1 was replaced with a new one.

  As shown in the above Examples and Comparative Examples, according to the present invention, the sponge titanium produced in the reaction vessel can be efficiently extracted, and the lifetime of the cap portion at the bottom of the reaction vessel at that time is also conventional. It was shown to be improved compared to

  According to the present invention, the production of sponge titanium can be performed smoothly, which contributes to the suppression of the production cost of sponge titanium.

It is a schematic cross section of the sponge titanium manufacturing apparatus of the present invention. It is a schematic cross section which shows the state after sponge titanium production | generation in the manufacturing apparatus of FIG. It is a schematic cross section explaining punching of the sponge titanium lump of the present invention. It is a schematic cross section explaining the punching of the conventional sponge titanium lump. It is a schematic cross section showing one embodiment of a punching jig and a floor board of the present invention. (A) is a schematic cross-sectional view showing a welded part before cutting in the cutting of the reaction vessel and the cap part of the present invention, and (b) is formed with a welding groove at the welded part and subjected to diameter expansion drilling. It is a schematic cross section which shows a back state, (c) is a schematic cross section which shows the joining state of the cap part side trunk | drum at the time of welding. It is a schematic cross section explaining the stage immediately before punching after the conventional sponge titanium lump production. It is a schematic cross section explaining the cutting of the cap part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Reaction container 10 Cap part 10A Cap part side trunk | drum 10B Cap part bottom part 10C The cap side trunk | drum 11 cut and separated The opening part 12 Titanium tetrachloride supply pipe 13 Inert gas introduction port 14 Exhaust port 15 Welding part 2 Molten magnesium 20 Sponge titanium lump 3 Base plate 4 Punching jig 5 Punching bar 6

Claims (9)

In a method of producing sponge titanium by magnesium reduction of titanium tetrachloride,
A part of the bottom part is a convex part protruding downward from the bottom part, and a punching jig is provided in the bottom part of the reaction vessel constituting the cap part having a cylindrical side body part ,
On the punching jig is provided a floor plate that can easily separate the sponge titanium mass from the punching jig ,
After filling magnesium on the flooring and dropping titanium tetrachloride to produce a sponge titanium lump,
Cutting the cylindrical side barrel of the cap to form an opening at the bottom of the reaction vessel;
A method for producing titanium sponge, wherein the sponge titanium mass is extracted from the reaction vessel by inserting a punch bar into the opening and pressing the punch jig.
  2. The method for producing titanium sponge according to claim 1, wherein the punching jig has a hollow structure and has a plurality of through holes on a surface of the punching jig. .   3. The method for producing titanium sponge according to claim 1, wherein a surface of the punching jig in contact with the floor plate has a flat surface or a convex shape.   The method for producing sponge titanium according to claim 1, wherein the floor plate is a flat plate having no through hole.   The method for producing titanium sponge according to any one of claims 1 to 4, wherein a ceramic layer is interposed between the floor plate and the punching jig.   The method for producing titanium sponge according to any one of claims 1 to 4, wherein a titanium sponge layer is interposed between the floor plate and the punching jig.   The method for producing sponge titanium according to any one of claims 1 to 6, wherein, when the cap portion is cut from the reaction vessel main body, a diameter for drilling is expanded after forming a welding groove.   The method for producing sponge titanium according to any one of claims 1 to 7, wherein only the titanium sponge is recovered by peeling off and removing the bottom plate adhered to the bottom of the titanium sponge extracted from the reaction vessel.   The sponge according to any one of claims 1 to 7, wherein after the bottom layer of the sponge titanium that has been in close contact with the floor plate is cut and removed, the remaining sponge titanium is crushed and sized to obtain a product sponge titanium. A method for producing titanium.

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