JPS60195009A - Production of block nitrides of titanium group - Google Patents

Abstract

PURPOSE:A compound of an element in the Ti group or an elementary metal is melted and nitridized as a nitrogen-containing gas is fed, then cooled down to give homogeneous and blocky nitrided of Ti group element in high productivity. CONSTITUTION:An oxide, hydride or halide of an element in the Ti group or its elementary metal is combined with a reducing agent such as coke, or when necessary, along with a catalyst such as hydrogen, then they are melted in the furnace 1 by means of electrode 2 to effect reduction. A nitrogen-containing gas is fed from the furnace 4 into the melt 5 to effect nitridization and the melt is cooled down to give block of nitride of Ti group element. The process according to the present invention enables smooth nitridization and high-production of TiN blocks of desired size.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing bulk titanium group element nitrides, ie titanium nitride, zirconium nitride or hafnium nitride.

Conventionally, methods for producing titanium nitride include (1) a vertical solid-gas phase reaction method in which powdered titanium metal is reacted in a nitrogen or ammonia stream to obtain titanium nitride, and (2) a method in which titanium hydride is thermally decomposed to obtain titanium nitride. After that, the reaction is carried out in a nitrogen or ammonia gas stream to nitrate, / to reduce the temperature.
There was also a method of in-phase-gas phase reaction in which titanium tetrachloride was reacted with a mixed gas of hydrogen and nitrogen or ammonia gas in a high-temperature gas phase to obtain titanium nitride.

However, methods (■) and (2) yield titanium nitride in the form of powder or fibers, and method (■) mainly yields titanium nitride for surface coating, both of which produce powder particles on the order of 1μ. Therefore, it was not possible to directly obtain bulk titanium nitride.

Therefore, in the past, it was mainly used as powder or IIAI.
At present, it is limited to applications where it can be used in a so-called powder state such as Ill form, and there have been no examples of directly producing a lump form by reaction.

However, although it is recognized that this substance is useful in the field of abrasive materials, for example, in order to obtain abrasive grains of the order of 0.31, it is necessary to first sinter the titanium nitride in the form of powder particles. After that, a process of pulverizing to a predetermined particle size must be adopted, and especially in this sintering process, since the melting point of titanium nitride is high, exceeding 3200°C,
The conditions were severe in terms of productivity, versatility, and adaptability, making it difficult to implement in practice. In other words, since no lumps were obtained during the reaction J3 and Dairef 1~, in order to obtain lumps, the once produced powdered titanium nitride would have to be reprocessed in a separate process to improve productivity, flowability, and A sintering process with poor workability has to be employed, and therefore, a method has been desired that would allow titanium nitride to be obtained in bulk.

Therefore, the purpose of this invention is to improve the reaction efficiency without using the so-called sintering method, which is undesirable in terms of productivity, processability, and economy, and also because it requires a separate process. - A method for producing titanium group element nitrides such as titanium nitride, which can be produced simultaneously, and is extremely homogeneous, as well as titanium group element nitrides such as zirconium nitride and hafnium nitride.
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In order to achieve the above object, the present invention melts an oxide, hydride or a metal of a titanium group element, adds a reducing agent such as coke or a catalyst such as hydrogen as necessary, and melts the A nitriding reaction is caused under these conditions, and the final target product, a lumpy titanium group element nitride, is obtained.

In other words, in the past, the reaction was caused according to the condition temperature of a normal nitriding reaction, but in this invention, the normal condition temperature is not adopted as the standard for setting the reaction conditions, but in particular the production state of the product substance is used. From the standpoint of turning the material into a lump, the reaction is caused based on the temperature at which it is maintained in a molten state. In other words, as mentioned above, the titanium group element nitride, which is a generated substance,
Although they have extremely high melting points, the oxides, hydrides, and halides of titanium group elements, which are the raw materials that can produce them, have extremely low melting points compared to the product materials, and the temperature conditions for their nitriding reactions themselves are extremely low. is even lower, and the melting point of the raw material itself is also sufficient to meet the temperature conditions for the reaction. Therefore, the raw material is first melted, the product is shaped into a bowl, and the nitriding process is carried out under this molten state. It is something that causes a reaction.

Of course, this is problematic because the nitriding reaction occurs under high temperature conditions that far exceed normal conditions, but in reality, nitriding occurs under these abnormal conditions. It was observed that the reaction proceeded and a homogeneous mass was obtained.

Examples of this type of raw materials include titanium metal, oxides of titanium group elements such as titanium oxide, zirconium oxide, and hafnium oxide, and titanium group elements such as titanium hydride, zirconium hydride, and hafnium hydride. Cognides of titanium group elements such as hydrides, titanium halides, zirconium halides, and hafnium halides are included.

This raw material may also contain an oxide of a titanium group element obtained by first subjecting a carbonized titanium group element to an oxidation reaction in a solid state in an electric furnace.

The drawing is a principle diagram showing an example of an apparatus used in this type of method, and numeral 1 indicates a so-called electric furnace consisting of a furnace body. 4 is a nitrogen-containing gas supply path formed by passing the electrode 2 through the shell, and 5 is a heated melt.

To explain the invention related to this method using this device, for example, a raw material and a reducing agent are added to a furnace body 1 in advance in an air atmosphere, melted and reduced by an electrode 2, and nitrogen-containing If gas is supplied, nitridation occurs, and after cooling, a lump material is obtained.

Alternatively, for example, the inside of the furnace body 1 may be placed in a nitrogen atmosphere in advance, and raw materials etc. may be added thereto for melting, reduction, and nitriding. Of course, in this case, some reaction occurs even before the raw material reaches a molten state, but due to the reduction reaction and the rapid heating of the melon, it is recognized that almost all of it will turn into lumps over time. It is being

Furthermore, for example, a method may be considered in which a raw material that has been molten in advance is introduced into a nitrogen atmosphere to appropriately obtain a lump of a desired size.

n5 f s L−−1−−ゝノkl;
Alternatively, any method that involves melting a halide or an elemental metal, adding a reducing agent or catalyst as necessary, and nitriding in this molten state is appropriate. .

Embodiments of the present invention will be described in detail below.

The manufacturing method, minerals produced, and analysis results are shown in a separate table.

Example 1 10 kg of rutile Nando and 3.0 kg of coke are thoroughly mixed. This is placed in an electric furnace as shown in the drawing and energized with an AC voltage of 120 V to produce a molten material. Next, this melt was nitrided in a mixed gas atmosphere of N2 gas and N1-13 gas to obtain a lump of 6.4%. Note that T'OzT i C is an intermediate product during the reaction.

(T'i (Cx Ny), x41 = 1)
, (Ti (Cx Oz), x + z = 1), (
Ti (NyOz), y +z = 1), (T
i (Cx NV Oz, x +y +z = 1
), but these intermediate products were again melted and reduced using an electric furnace in a nitrogen-containing gas atmosphere such as nitrogen gas. It was found that if nitriding is carried out, bulky iN is less likely to be produced.

Example 2 10 kg of titanium carbide was placed in an electric furnace in the same manner as in the above example, and a mixed gas of N2 gas and CO gas was added as a pre-reaction to avoid producing titanium oxide.

At this time, the reaction changed from a solid state to a molten state as titanium oxide was produced. This was followed by NZ
A mixed gas atmosphere of gas and N'H3 gas was created, the gas flow rate was adjusted to 59/min, and electricity was applied as in the above example. As a result, 8.1 kg of bulk titanium nitride was obtained.

Example 3 10 kg of titanium hydride was put into the same electric furnace, and the gas flow was 15 kg.
Electricity was applied at A/min under an NZ gas atmosphere. As a result, 9.6 kg of bulk titanium nitride was obtained.

Example 4 10kQ of titanium tetrachloride was put into an electric furnace, and the gas flow rate was set to 5.
Under a mixed gas atmosphere of NZ gas adjusted to L/mi++ and N1''3 gas, -C current was applied, and bulk titanium nitride 6k was applied.
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(Next page below) Chemical analysis value [1 ([-] Note) * By elemental analysis ** Identification by X-ray diffraction method As described above, this invention can identify titanium group element nitrides in a bulk state and Since it provides a method for 1q in a homogeneous state, for example, when using this type of material as abrasive grains in the field of abrasive materials, there is no need to take the trouble of adopting a sintering method as a separate process. It is a 1c product that can exhibit remarkable effects in terms of productivity, processability, and cost saving. J3 Of course, it can be applied not only to this type of use, but also to other uses where a separate sintering method is required to make it into a lump, and it is extremely useful for a wide range of fields of use. There is something big.

[Brief explanation of drawings]

The drawing is a principle diagram showing an example of an apparatus used when carrying out an example of the method according to the present invention. Agent 1. Patent attorney Taiho Oshima

Claims (1)

[Claims] (1) Melt oxides, hydrides, or halides of titanium group elements, or metal particles, add a reducing agent such as coke or a catalyst such as hydrogen as necessary, and nitride the oxides, hydrides, or halides of titanium group elements, add a reducing agent such as coke or a catalyst such as hydrogen, and nitride the oxide, hydride, or halide of a titanium group element. A method for producing bulk titanium group element nitrides.