JPS62185841A - Manufacture of metallic niobium or metallic tantalum - Google Patents

Abstract

PURPOSE:To simplify the process of preparing undermentioned compound to be a raw material, by treating the undermentioned compound under reduced pressure to form a prescribed chemical species in the titled process for reducing a compound of Nb or Ta with fluorine and ammonium. CONSTITUTION:The compound of Nb or Ta with fluorine and ammonium is heated to 50-500 deg.C in the reduced state of <=150mmHg absolute pressure, by which the compounds of Nb, for example, are transformed into prescribed compounds, respectively, as shown in formulas I, II. The resulting chemical species are close to NH4NbF6. Subsequently, the above chemical species are introduced into the reduction stage, where they are heated up to >=150 deg.C in the presence of metallic Zn, metallic Mg, and metallic Al in an inert or reducing air flow. In this way, as to Nb compounds, for example, metallic Nb is generated as represented in formulas III-V. Further, the same applies to Ta.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for producing niobium metal or tantalum metal.

Conventional technology] Conventionally, metal niobium (Nb) or metal tantalum (Ta
) can be obtained by reducing niobium or tantalum chloride with metallic magnesium or metallic sodium, and by reducing niobium or tantalum oxide, potassium compound, or sodium chloride with metallic aluminum or metallic magnesium. Common.

Furthermore, as a molten salt electrolysis method, a method for obtaining metal by electrolyzing a compound of sodium and fluorine of niobium or tantalum or a compound of potassium and fluorine has also been put into practical use.

[Problems to be Solved by the Invention] In addition, the present inventors have disclosed a method for obtaining a metal by decomposing a compound of niobium and tantalum with ammonium and fluorine in a hydrogen stream, but the ammonium salt is Although it is a crystal that is easy to decompose, depending on the formation conditions, not only the number of ammonium and fluorine changes to 11, but also the number of oxygen changes, so hydrogen gas reduction is often difficult. It has the disadvantage that advanced control technology is required for industrial use.

[Means for Solving the Problems] The present invention was developed during research into how to overcome the above-mentioned drawbacks. A method for producing niobium metal or tantalum metal, which is characterized by simplifying the process of creating a compound of fluorine and ammonium from these metals (Nb, Ta) as raw materials by converting them into certain chemical species through reduced pressure treatment. This is related to.

Therefore, in the present invention, by heating a compound of fluorine and ammonium of niobium or tantalum at a temperature range of 50°C to 500°C under a reduced pressure of 150 mHy or less, part of the fluorine and ammonium of the compound is removed. A first step of separating crystal water and adhering water; and a niobium or tantalum compound obtained in the first step in the presence of metal zinc, metal magnesium, and metal aluminum in an inert gas flow or a reducing gas flow. To provide a method for producing niobium metal or tantalum metal, which comprises a second step of heating to 150° C. or higher to obtain niobium metal or tantalum metal.

Further, the present invention provides a method of heating a compound of niobium or tantalum fluorine and ammonium in a reduced pressure state of 150 nm HIF or less in a temperature range of 50°C to 500°C to form part of the fluorine and ammonium of the compound and crystals. First step of separating water and attached water; The niobium or tantalum compound obtained in the first step is heated in an inert gas stream and a hydrogen stream in the presence of metallic zinc.
A second step of heating to 50°C or higher to obtain niobium metal or tantalum metal and also create a compound of fluorine and zinc and a compound of fluorine and ammonium; The compound of fluorine and zinc obtained in the second step is heated in a hydrogen stream. A third step of producing hydrogen fluoride, fluorine gas, and metallic zinc by decomposition; and a fourth step of supplying the metallic zinc obtained in the third step to the second step. To provide a method for producing tantalum.

[Function] The method of the present invention will be explained based on the accompanying drawings, but it should be understood that the present invention is not limited to these examples.

FIG. 1 is a flow sheet showing a basic method for producing Nb or Ta according to the present invention.

The chemical species of the fluorine and ammonium compounds of Nb or Ta vary greatly depending on the HF concentration, DH potential concentration, and salting-out agent concentration during crystal formation. An example of this is shown below.

(N　H<)sTaHF　s・1　, 5　Ht.

(N　H<)iTaF　*・2　Ht.

(NH4>, TaF13HtO (NH<)zT a F t ・4 Hx 0(NH
4) 3NbF, ・H2O (NH,), N bF?・H20 (NH4>3NbHFs・1.5H20(NH,)3
NbOF m-2820 In addition to the above, Nb or Ta
It is known that several types of fluorine and ammonium compounds exist.

When the above-mentioned monster is placed in a container and heated within the range of 50°C to 500°C while the absolute pressure inside the container is reduced to 150 IHy or less, it changes into a certain compound as shown in the following formula.

(NFI-)iTaHF*4.5H20-N)InTa
F a + 2NH4F↑10HFi+1.5H20↑(
N114>2TaF? -4H20-+NH4TaF5
+ NH4F↑+41120↑(H,), NbHFI・
1.5H, O→NH, NbF, + 2NI1. F T
+ IFi+1.5H, 0↑(NH4), NbF,・
HzO → nH, NbF, + NH, F↑+)20↑ The chemical species generated by the vacuum decomposition process are close to NH, NbF, or N H4TaF s, and this is the value determined from the 1H scientific analysis results. Therefore, the molar ratio of NH=:Ta:F is not limited to 1:1:6.

In order to prevent the N H and F gases generated by decomposition in the next reduction step from becoming NH and HF, and further to NF and HF in the high temperature region and interfering with metal production, Hx O and N H3 are contained in the product. Decrease the ratio.

Next, NH, TaFa or NH, N obtained in the first step
A compound close to bFa is introduced into a reduction process and heated to 150°C or higher in an inert gas flow or a reducing gas flow in the presence of metal zinc, metal aluminum, or metal magnesium to reduce the metal as shown in the following formula. Tantalum or niobium metal is produced.

NHnTaFa+2.5Zn-+Ta+Nt(J↑+2
．． 5ZnF2NH<TaFi + 2.5My-+Ta
+NH4F↑+2.58gF.

NH4NbFs + 2.5Zn-4Nb-i-Ni1
-F↑+2.5znF2NH1NbFi + 2.5M
2-*Nb+ NH4F↑+2.5MyFz The decomposition reaction is carried out in an inert gas flow, a reducing gas flow, or at an absolute pressure of 10-'
a+mHI? By thermal decomposition under reduced pressure below,
Coexisting A1. Reacts with M, , and Zn.

In the decomposition in a hydrogen stream disclosed by the present inventors in Japanese Patent Application No. 126995/1980, T a F s→T
It has the disadvantage that it changes to a F a and becomes a solid, and the reaction temperature becomes significantly high, so metallization must proceed more rapidly than TaF5.

Zn is a reaction product of niobium metal or tantalum metal
Even if F,, A 11 F s, MgF', NH, and F are mixed in, it is extremely easy to remove them by specific gravity separation or pickling separation.

The removed AlF3 and MgF2 can be sold to the aluminum smelting industry and the electronics industry without any disadvantage.

FIG. 2 is a flow sheet showing an application example in which the reducing agent is limited to low-cost zinc. As in FIG. 1, the crystallized product is put into a vacuum decomposition step and heated to 50°C to 500°C under reduced pressure of 150+*mHy or less to obtain ammonium, fluorine, crystal water, and attached water. The residual Nb or Ta ammonium and fluorine compound is put into the reduction process, and the temperature is raised to 15% in the coexistence of metallic zinc.
Zinc fluoride collected in the 0 separation step to obtain metal Nb or metal Ta and zinc fluoride-NH, F gas at 0°C or higher is thermally decomposed in a hydrogen gas stream, as shown in the following formula. It becomes metallic zinc and I-IF gas.

Zn+2HF-Zn+2HF Metallic zinc is recycled to the reduction process.0 Decomposition product gas is absorbed in the gas absorption process and recycled to the process of producing fluorine and ammonium compounds of Nb and Ta.

In the present invention, the reduced pressure reactor may be a known closed external heating furnace with various structures such as a rotary type and an internal stirring type.

The metal zinc, metal aluminum, and metal magnesium used as the reducing agent in the present invention can be in a gaseous state, a liquid state, or a mixture thereof.

The inert gases that maintain the reaction conditions in the reactor are argon,
Helium or nitrogen gas, with N as a reducing gas
2. Various hydrocarbon gases such as CO or general 2〇mHn can be mentioned.

In the present invention, as a compound of fluorine and ammonium of Nb or Ta, which is a raw material, a fluoride complex of Nb or Ta extracted with an extractant selected from the group of neutral phosphoric acid esters and phosphonium described below is used. Concentrate the separated solution with an aqueous solution containing it or
This is a crystal produced by adding Hs.

(i) (b) (c) (d) In the above formula, R represents an alkyl group, and those having 4 to 22 carbon atoms are generally used. In addition to neutral phosphoric acid esters, commonly used extractants include alkylamines; primary amines: expressed as RNH2, where R is an alkyl group having 4 to 22 carbon atoms.

Secondary amine: Represented as R, N or RtNH, where R is an alkyl group having 4 to 22 carbon atoms.

Tertiary amine: represented by R3N or R,NH, in the formula R
is an alkyl group having 4 to 22 carbon atoms.

The ketone used to make the raw material of the invention is then selected from the following group:

C=0 R' In the formula, R and R' represent an alkyl group or an aryl group, each having 3 to 22 carbon atoms.

The amide is also selected from the following group:

In the formula, R and R' represent an alkyl group or an aryl group, each having 4 to 25 carbon atoms.

[Example] The present invention will be specifically explained with reference to Examples below. In the present invention, metal Nb or metal Ta is produced after a compound of Nb or Ta with fluorine and ammonium is decomposed under reduced pressure. It should be understood that the invention is not limited to these examples.

and [ 15% trioctylphosphonium oxide (TOPO)
+50% trioctyl phosphate (TOP) +35%
A compound (crystal) of Ta, NH4, and F obtained by exfoliating Ta ions extracted into an organic solvent composed of kerosene with a 2509/I N 84 F-containing solution was placed in a vacuum container and vacuumed. Use a pump to increase the pressure inside the container to 1CI'm5
After reducing the pressure to Hy, it was gradually heated to 140°C, and the obtained solid substance was analyzed, and the values were as shown in the lower row of the following table.

No. 1 - Person (wt%) N HTa F Raw material before vacuum treatment 9.61 3.74 41.74 3
8.99 Raw materials after vacuum treatment 4.85 1.27 57.
91 35.72 This was thought to indicate the composition of NHnTaFs.

20 g of this intermediate was put into a reactor, and 280% of albo
+ 65 while adding 20% hydrogen mixed gas and gaseous zinc
After raising the temperature to 0°C, the inside was inspected and 11F of black powder was obtained.

Chemical analysis and X-ray diffraction of this black powder confirmed that it was metal Ta.

and 1λl N H4T a F obtained by vacuum decomposition in Example 1
A compound close to s, 20y, and metal zinc 151F were placed in a reactor, and the pressure was reduced to lmmHg using a vacuum pump, and then argon gas was supplied, and the pressure was further reduced to 10-ImmHg.
After cooling, the temperature was gradually raised to 600° C., and the resulting solid was pickled with 50 g/l H 2 SO, and the weight of the black powder was 11.2 g.

Chemical analysis and X-ray diffraction of this black powder confirmed that it was metal Ta.

250g/192 of Nb ions extracted into 100% MIBK
The compound (crystal) of Nb, NH, and F obtained by contacting and exfoliating the INH, F-containing liquid was placed in a vacuum container, and the pressure inside the container was reduced to 10° HfI using a vacuum pump. After that, the solid material obtained by gradually heating to 180°C (
When the residue in the container was analyzed, the values shown in the lower row of the following table were obtained.

(wt%) N HTa F Raw material before vacuum treatment 11.97 4.68 26.98
49.71 Raw material after reduced pressure treatment 5.21 1.79 4
1.38 52.70 This corresponds to NH, NbF.

Put 20g of the substance obtained by the reduced pressure treatment into a reactor, heat it to 600°C while adding a mixed gas of 80% argon and 20% dehydrogen and gaseous zinc, and then cool it.
When the inside was inspected, 7.5 g of black powder was obtained.

When the obtained black powder was subjected to chemical analysis and X-ray diffraction, it was confirmed that it was metallic Nb.

and 11 Put 20g of the compound similar to NH, NbF@ obtained by vacuum decomposition in Example 3 and 15y of metal zinc into a reactor, reduce the pressure to 1 ring mHg with a vacuum pump while supplying argon gas, and then gradually The temperature was raised to 600° C., maintained at 600° C. for 2 hours, and then cooled. The obtained solid was pickled with 50 g/1 H 2 SO, and 7.6 g of black powder was obtained in total. Chemical analysis and X-ray diffraction of this black powder confirmed that it was gold lNb.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing the basic method for producing Nb or Ta according to the present invention, and FIG. 2 is a flow sheet showing an application example in which the reducing agent is limited to low-cost zinc. Patent applicant: Nishimura Watanabe Extraction Laboratory Co., Ltd. Figure 2

Claims (1)

[Claims] 1. A compound of niobium or tantalum fluorine and ammonium is heated under reduced pressure of 150 mmHg or less.
A first step of separating part of the fluorine and ammonium, crystal water, and adhering water of the compound by heating in a temperature range of 0°C to 500°C; and Metal niobium or metal tantalum, which comprises a second step of heating to 150°C or higher in the presence of metal zinc, metal magnesium, and metal aluminum in an active air flow or a reducing air flow to obtain metal niobium or metal tantalum. manufacturing method. 2. A compound of niobium or tantalum fluorine and ammonium is heated under reduced pressure at an absolute pressure of 150 mmHg or less.
The first step is to separate part of the fluorine and ammonium, crystal water, and adhering water from the compound by heating in a temperature range of 0°C to 500°C; the niobium or tantalum compound obtained in the first step is inactivated. A second step of heating to 150° C. or higher in the presence of metallic zinc in a gas stream and a hydrogen stream to obtain metallic niobium or metallic tantalum, as well as producing a compound of fluorine and zinc and a compound of fluorine and ammonium; A third step of producing hydrogen fluoride, fluorine gas, and metallic zinc by decomposing the obtained compound of fluorine and zinc in a hydrogen stream; and supplying the metallic zinc obtained in the third step to the second step. A method for producing niobium metal or tantalum metal, comprising a fourth step.