JPH03249144A - Production of niobium halide, niobium oxide, niobium nitride, niobium carbide, and metallic niobium - Google Patents

Abstract

PURPOSE:To efficiently produce high purity niobium halide by forming ferroniobium into ferroniobium nitride by a solid nitriding method, applying iron removal to this ferroniobium nitride by means of acid treatment, and carrying out halogenation treatment. CONSTITUTION:Ferroniobium is used as raw material and formed into ferroniobium nitride by a solid nitriding method. This ferroniobium nitride is subjected to iron removal by means of acid treatment and formed into niobium nitride, which is subjected to halogenation treatment so as to be formed into niobium halide. Metallic niobium can be obtained by allowing this niobium halide to react with active metals, such as carbon, a, Na, and Mg, at high temp. or by subjecting the niobium halide to molten-salt electrolysis. Further, niobium oxide is formed from the niobium halide, and metallic niobium can he obtained by using an aluminum thermit method and a carbon reduction method. Moreover, niobium nitride can be obtained by allowing the niobium halide to react with ammonia gas, and metallic niobium can be obtained by subjecting the above niobium nitride to vacuum heat treatment.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides niobium halides, niobium oxides, niobium nitrides,
The present invention relates to a method for producing niobium carbide and niobium metal.

[Conventional technology and Section H] Metallic niobium is used as a niobium source for super alloys, etc.
In recent years, particularly high purity products have been required as electronic materials. Furthermore, niobium oxide, niobium carbide, and the like are used as pigments or ceramic raw materials, and there is a demand for highly pure and inexpensive products.

In order to obtain the above product, it is considered that one premise is that niobium halide can be produced at low cost. Conventional methods for producing niobium halide include a method of directly halogenating and refining ferron niobium, and a method of halogenating a mixture of niobium oxide or niobium ore with carbonaceous material.

In the method of directly halogenating ferroniobium, several tens of percent of the iron contained in ferroniobium becomes iron halide and is generated in large quantities, making it extremely difficult to achieve high purity industrially. Stable production is extremely difficult due to blockage caused by adhesion.

When using niobium ore as a raw material, a large amount of slag is generated, which is difficult to process.
When using it as a raw material, high-purity niobium oxide is expensive;
Each method has its own problems, such as not being an economical manufacturing method. In addition, the reaction when halogenating by mixing with carbonaceous material is high temperature, and the CO generated by this reaction is
The gas produces acid halides of niobium, making it difficult to achieve high purity.

In addition, as a method for producing niobium oxide, niobium ore is HF
There are methods such as dissolving with H2SO4, solvent extraction and roasting, and adding ammonia to an aqueous solution of niobium halide, filtering and roasting. In the former method, the solvent used for solvent extraction is expensive and the separation efficiency is low, so multi-step treatment is required, and the resulting niobium oxide is expensive. Furthermore, the latter method has problems such as the high cost of niobium halide produced by the conventional method.

Furthermore, niobium carbide can be obtained by reacting niobium oxide with carbonaceous material at high temperature, but this niobium oxide is expensive.

Conventional methods for producing niobium metal include a chlorination method in which carbon and active metals such as Al, Na, and Mg are reacted at high temperatures using niobium chloride, which is purified by chlorinating ferroniobium, and niobium oxide is converted into aluminum thermite. There is an aluminum thermite method obtained by reaction, and a carbon reduction method in which niobium oxide is reacted with carbon at high temperature.

In the method using the above chlorination method, when the entire amount of ferroniobium is chlorinated, a large amount of iron chloride is produced as a by-product, making it difficult to produce stable chloride.Also, in the aluminum thermite method, several percent of aluminum remains in the product. There is a problem.

Furthermore, since the carbon reduction method requires a high temperature of nearly 2000° C., there is a problem that equipment costs and power fuel costs increase.

In addition, the conventional method using niobium ore as a starting material has a problem in that it is difficult to obtain niobium ore because exports of ferron niobium from niobium-rich countries have increased in recent years.

In view of the above circumstances, the present invention has been extensively studied and is intended to provide a method for producing niobium halides, niobium oxides, niobium nitrides, niobium carbides, and metal niobium with good production efficiency and high purity.

[Means and effects for solving the problem] The method for producing niobium halide according to the present invention includes producing ferroniobium nitride by a solid nitriding method using ferroniobium, and deironating the ferrochrome nitride by acid treatment. Niobium nitride is used, and the niobium nitride is subjected to halogenation treatment to obtain niobium halide.

Niobium oxide can be obtained by a hydrolysis method, a neutralization precipitation method, or an oxidative roasting method using the niobium halide.

Further, niobium nitride can be obtained by reacting the niobium halide with ammonia gas, and metallic niobium can be obtained by heating the niobium nitride in a vacuum.

The ferroniobium used as a raw material can be of commercially available purity.Although the niobium content is related to manufacturing cost, as long as it is within the commercially available composition range, there is no problem economically or in terms of quality. be.

In the nitriding process, ferroniobium is converted to ferroniobium nitride. This is done in order to separate the ferroniobium into niobium nitride and the iron metal phase by nitriding so that iron can be removed in the next step of acid treatment. Nitriding of ferroniobium can be carried out using a vacuum heating furnace in a nitrogen atmosphere at a temperature of 800°C or higher, preferably 1100 to 1400°C. At temperatures below 800°C, iron removal in the next step is insufficient, and at temperatures above 1400°C, special nitriding equipment is required, which is economically disadvantageous.

In the nitriding process, it is desirable to crush before or after nitriding in order to increase the efficiency of nitriding and deironation, and it is also possible to repeat crushing and nitriding as necessary.

The iron removal process is a process in which niobium nitride is obtained by removing iron from ferroniobium nitride by acid treatment. This acid treatment was conceived based on the fact that the structure of ferroniobium nitride is separated into niobium nitride and iron metal phases, and the acid treatment is carried out using ordinary acids such as sulfuric acid and hydrochloric acid. Various methods can be considered for the acid treatment, but economically it is desirable to vigorously stir the powdered ferroniobium nitride, react it with the acid in a tank, collect the solid by filtration, and dry it.

Niobium nitride obtained in the iron removal process has fine particles (1 to 10μ
In the halogenation process, halogen gas is used at a relatively low temperature (approximately 150 to 500°C).
Niobium halide can be obtained by

Various methods can be considered for halogenation, but
It is desirable to react the niobium nitride in a fluidized tank and use several stages of condensers to remove the generated trace impurity halide.

By doing this, high purity niobium halide can be recovered in the halogenation process.In the present invention, iron and other impurities are removed in the previous iron removal process, so the iron halide in this halogenation process is As a result, there are fewer problems such as clogging of pipes, etc., and the amount of impurities and halogen used during purification is also reduced, making it possible to economically and stably produce high-purity niobium halides.

A method in which niobium halide is reacted with active metals such as carbon, Al, Na, Mg, etc. at high temperature, or by molten salt electrolysis,
Metal niobium can be obtained. Furthermore, niobium oxide can be produced from niobium halide, and metallic niobium can be obtained using the aluminum thermite method or the carbon reduction method. Furthermore, niobium nitride can also be obtained by reacting niobium halide with ammonia gas, and metal niobium can also be obtained by subjecting this to vacuum heat treatment.

In this way, niobium oxide, niobium nitride, niobium carbide, and metallic niobium can be produced from niobium halides by the method of the present invention without requiring special equipment.

[Example] A lump of ferroniobium was crushed or ground to obtain ferroniobium powder with a particle size of 44 μm or less.

This composition is shown in Table 1-(1). The compositions in Table 1 are shown in weight ratios, unless otherwise indicated are percentages, and those shown in ppm are indicated in the table. In addition, Table 1 (wt%) 500 kg of the ferroniobium powder was put into a nitriding furnace, and 7
Nitriding was carried out for 24 hours under an atmosphere of an elementary pressure of 800 Torr and a temperature of 1250°C. The weight of the ferroniobium nitride obtained here was 545 kg, which was lightly sintered, and was crushed into a powder of -150μ.The composition of this ferroniobium nitride powder is shown in Table 1-(2) , 20
In a reactor with a stirring function and a volume of 11S, 0 kg was put into 6001 water, which had been charged in advance, and the H2 was heated without stirring.
Continuously add SO<-144kg at 88r, then
Stirring was continued for 16 hours. The slurry after the acid treatment was filtered, washed with water, repulped with aqueous ammonia, filtered again, washed with water, and dried. The composition of 124 kg of niobium nitride obtained is shown in Table 1-(3).

Next, a niobium halide is produced by a halogenation process from the niobium nitride, and an example in which chlorine is used as the halogen will be described. As the halogen, not only chlorine but also fluorine, bromine, and iodine can be used.

Niobium chloride was synthesized from the niobium nitride in a chlorination furnace shown in FIG. Figure 1 is a block diagram of the chlorination furnace. In Figure 0, 1 is a reactor, into which raw materials niobium nitride and chlorine gas are charged. 2 is a high-temperature trap, in which chloride, which has a boiling point higher than that of niobium chloride, out of the gas discharged from the reactor 1 is trapped as a residue. 3 is a high temperature condenser where the product niobium chloride is trapped and recovered. 4 is a low-temperature capacitor that traps chlorides, such as iron chloride, which have a boiling point lower than that of niobium chloride. 5 is exhaust gas treatment equipment. The chlorination furnace shown in FIG. 1 is an apparatus in which raw materials are continuously charged and the product niobium chloride is recovered.

The reactor 1 is charged with the niobium nitride and chlorine gas. The temperature of the high temperature trap 2 is the product NbC1,
The boiling point of FeCl3 to be removed is 274℃ and the boiling point of FeCl3 to be removed is 315℃.
℃, the temperature is controlled to be slightly lower than 315℃,
High temperature trap 2 collects and removes FeCl3 and other high boiling point components.

In the high-temperature condenser, NbCl can be recovered in liquid and solid form, and the temperature is controlled at such a temperature that trace amounts of low-boiling components (for example, 5iC14) are not mixed.

In this example, the temperature of the reactor 1 is 500°C,
High temperature capacitor 3 is set to 200℃, low temperature capacitor 4 is set to 1
After replacing the reactor 1 with an inert gas and controlling the temperature to 00°C, CI2 and Ar gas were supplied at a flow rate of 108 m''/mix, and 3 g of niobium nitride having the composition shown in Table 1-(3) was added. /■i■.As a result, the niobium chloride recovered in the high-temperature condenser 3 was 6.8x/e+i.0The composition of the recovered niobium chloride is shown in Table 1-(4).
Shown below.

As a comparative example, an attempt was made to collect niobium chloride in the high-temperature condenser 3 by directly charging ferroniobium into the reactor 1 and simultaneously supplying 01□ and Ar gas, but a large amount of chloride was found in the high-temperature condenser 3 and the piping. Iron (FeCls) adhered to the pipes, clogging the pipes, and stable production of niobium chloride was not possible.

The precipitate obtained by neutralizing the niobium chloride shown in Table 1-(4) with aqueous ammonia was filtered and collected.

The composition of the niobium oxide obtained by roasting the precipitate was
The composition of niobium carbide obtained from the niobium oxide in Table 1-(5) by the carbon reduction method is shown in Table 1-(5), and the composition of niobium carbide obtained from the niobium oxide in Table 1-(5) is shown in Table 1-(6). Table 1-(7) shows the composition of niobium metal obtained from niobium oxide by the aluminum thermite method.

[Effects of the Invention] According to the method for producing niobium halide according to the present invention, ferron niobium is made into nitride ferron niobium by a solid nitriding method, and this is treated with an acid to remove iron, and then subjected to a halogenation treatment, resulting in high production efficiency. Highly pure niobium halide is obtained, and using this as a raw material, highly pure niobium oxide, niobium carbide, or niobium metal can be obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the chlorination furnace used in this example. 1... Reaction furnace, 2... High temperature trap, 3... High temperature condenser, 4... Low temperature condenser, 5... Exhaust gas treatment device.

Claims (8)

[Claims] (1) A nitriding step in which ferroniobium nitride is obtained by a solid-state nitriding method using ferroniobium as a raw material; a deironation step in which the ferroniobium nitride is treated with an acid to remove iron to produce niobium nitride;
and a halogenation step of halogenating the niobium nitride to obtain niobium halide. (2) A method for producing niobium oxide from the niobium halide obtained in claim 1 by a hydrolysis method, a neutralization precipitation method, or an oxidative roasting method. (3) A method for producing niobium nitride using ammonia gas from the niobium halide obtained according to claim 1. (4) A method for producing niobium carbide by adding carbon to the niobium oxide obtained according to claim 2 in a high temperature and reduced pressure atmosphere. (5) A method for producing metallic niobium by reacting the niobium halide obtained according to claim 1 with an active metal such as carbon, Al, Na, or Mg at high temperature. (6) A method for producing niobium metal by thermally decomposing the niobium halide obtained according to claim 1. (7) A method for producing metallic niobium by using the niobium oxide obtained according to claim 2 by the aluminum thermite method. (8) A method for producing metallic niobium by thermally decomposing the niobium nitride obtained according to claim 3 in a vacuum.