JPS63243231A - Production of metallic niobium - Google Patents

Abstract

PURPOSE:To simplify a process and also to improve yield, by carrying out solvent extraction, back-extraction, Ta extraction, etc., and forming Nb halide at the time of producing Nb from a mixed solution of HF and sulfuric acid containing metallic impurities such as Nb, Ta. CONSTITUTION:(a) An organic solvent is brought into contact with the above-mentioned mixed solution to carry out the selective extraction of Nb and Ta, and the organic solvent is brought into contact with an aqueous solution containing NH3 and HF so as to extract Nb and Ta to the aqueous-solution side. (b) An organic solvent or adsorbent is brought into contact with the above aqueous solution to remove Ta by selective extraction or adsorption. (c) NH3 gas and NH4OH or KOH and KF are added to the Nb-containing aqueous solution from which back-extracted Ta ions are removed so as to form a precipitate containing Nb, F<-> and NH<+> or K<+>. (d) One or more kinds among sulfuric acid, hydrochloric acid, HF, etc., are added to the above precipitate and/or the Nb-containing aqueous solution prepared in stage (b) to dissolve the precipitate and also to regulate pH, with which one or more kinds among O- containing organic solvents, such as ester and ether, are brought into contact. Then, Nb halide is extracted in the above solvents, and, after the solvents are removed, the Nb halide is brought into contact with Na, Ca, etc., so as to be formed into Nb.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for producing a niobium halide.

[Conventional technology/problems] Conventionally, as a method for producing niobium metal, niobium rarely exists alone in raw materials, and mostly coexists with tantalum, so solvent extraction technology is used for -m. and one or more metal impurities such as Fe, Mn, Ti, S
n, Sb, W, Ni, Co, Cu, Na, NH4,
Zn, Mo, Si, AI, Ca, ■, Li, Th, etc. ions and tantalum ions are separated, and then K C1, K
○■4 or Nto! By contacting an aqueous solution containing , and HF with an organic solvent containing extracted niobium ions, crystals of Nb0F&, (NH-)2N bOF s
The method of producing niobium precipitate containing crystals or NH, and HF, and further oxidizing it in the atmosphere to produce N b 20 s, which is then reduced with carbon or with AI, is the method of producing 2NbOF. There is a method of obtaining metallic niobium by reducing crystals etc. in a molten salt electrolytic bath.

Metallic niobium obtained by these conventional methods has the drawback that it is often contaminated with impurities and must be purified several times using an electron beam furnace or the like.

[Means for Solving the Problems] The present invention is based on the use of raw materials normally found in naturally occurring mineral resources such as tantalite, columbai, struberite and pyrochlore, or from industrial wastes such as the production of titanium tetrachloride. This is a method for producing high-purity metal niobium all at once from industrial residue, tin slag, scrap from tantalum capacitors, and scrap generated during the production of superconducting materials. The process is long and the yield is low, as it consists of the steps of separating Ta and metal impurities such as Fe, Mn, Ti, etc. to create purified Nb2O5, and then using carbon or metal A1 to create metallic niobium. This overcomes this drawback.

Therefore, the present invention provides a method for producing niobium metal from a mixed solution of hydrofluoric acid and sulfuric acid that mainly contains niobium and in which one or more metal impurity ions including tantalum coexist. One or more than 2ffi of organic solvents selected from the group of ketones, the group of neutral phosphate esters, the group of alkylamines, and the group of amides, the organic solvent (A) diluted with petroleum hydrocarbon. Niobium and tantalum are preferentially extracted from the mixed liquid by contacting them, and the organic solvent (A> is replaced with water, N H3 and HF, or Ni + and H
A first step of contacting with an aqueous solution containing F and back-extracting the niobium and tantalum contained in the organic solvent (A) into the aqueous solution and regenerating the organic solvent (A); (b) the back-extracted One or more organic solvents selected from the group of ketones, the group of neutral phosphate esters, the group of alkyl amines, and the group of amides, in an aqueous solution mainly containing niobium and coexisting with tantalum, A second step of preferentially adsorbing or extracting tantalum in the aqueous solution by contacting with an organic solvent (B) diluted with a petroleum hydrocarbon or an adsorbent; (c) removing back-extracted tantalum ions; Add NH, gas and NH4OH or KO to an aqueous solution containing niobium.
a third step consisting of adding H and KF and preparing a precipitate containing niobium, F''' and NH4+ or niobium, F- and N+; and (d) containing the niobium obtained in the second step. H, SO4, H
After adding one or more acids selected from the group of Cl, HF, HI and HBr to dissolve the precipitate and adjust the H+ ion concentration, the ester group, the ether group,
By contacting one or more oxygen-containing organic solvents (C) selected from the group consisting of ketones and alcohols, the niobium ions in the aqueous solution are converted into halogenated metal complexes using oxygen-containing organic solvents (C). C), then
A fourth step of regenerating the oxygen-containing organic solvent (C) and producing a niobium halide by heating/evaporating or heating/distilling at normal pressure or reduced pressure; and (e) the niobium halide obtained in the fourth step. Provided is a method for producing niobium metal, comprising a fifth step of producing niobium metal by bringing a halide of niobium into contact with elemental metals Na, Ca, Pb, and Zn and/or an alloy mainly composed of these metals. There is something to do.

[Function] From raw materials called tankrite, columbite, struberite, and pyrochlore, or from industrial waste such as titanium tetrachloride manufacturing residue, tin slag, superconducting wire processed product scrap, or solids such as niobium and iron alloys. containing mainly niobium and containing tantalum and one or more metal impurities such as Fc, Mn, Ti, S
n, Sb, W, Ni, Co, Cu, Na, NH,...
Zn, Mo, Si, A1. In a mixed solution of hydrofluoric acid and sulfuric acid in which ions such as Ca, V, Li, and Th coexist, a mixture selected from the group consisting of ketones, neutral phosphate esters, alkyl amines, and amides is added. The niobium ion in the mixed solution and T
Preferentially extracts a ions.

Here, if the concentration of one or more types of Kinatsu impurity ions co-extracted into the organic solvent (A) is unacceptable, the organic solvent (A) may be replaced with water or an aqueous solution containing NH and HF. Metal ions with a smaller extraction distribution ratio than niobium ions and Ta ions can be selectively transferred from the organic phase to the aqueous phase by contacting the organic solvent (A> with water or N H's and HF). or from 0 or more steps of contacting with an aqueous solution containing + and HF, extracting and back-extracting niobium and tantalum contained in the organic solvent (A) to the aqueous solution side and regenerating the organic solvent (A), The first aspect of the present invention
The process will take place.

The second step of the present invention is to add a back-extracted aqueous solution mainly containing niobium ions and coexisting with Ta ions to a selected from the group consisting of ketones, neutral phosphate esters, alkyl amines, and amides. An organic solvent comprising:
It consists of preferentially extracting/removing or adsorbing/removing Ta ions in the aqueous solution by bringing them into contact with an organic solvent (B) diluted with a petroleum hydrocarbon or an adsorbent.

In the third step of the present invention, NH3 gas and NH4OH or KOH and KF are added to the aqueous solution from which Ta ions have been removed from the back-extraction solution to extract niobium, F- and N- as shown in the following formula.
H,! or by producing a precipitate containing niobium, F- and niobium.

Precipitate H2N in the region where pF is low
b OF s +2 NH)→(NH-)2 N
bo F s ↓ pH is high <, precipitate H2N in the region where pF is large b OF s + N H2 → (NH,)
N bo 2F 2↓ Part 1 above made in the 3rd process
H, SO, HCI, II, H
After adding one or more acids selected from the group of Br and HF to dissolve the precipitate and adjust the H+ ion concentration, the ester group, ether group, cologne group and The niobium ions in the solution are extracted into the oxygen-containing organic solvent (C) as a halogenated complex by contacting with one or more oxygen-containing organic solvents (C) selected from the group consisting of alcohols. Here, if the concentration of one or more types of Kinosho impurity ions co-extracted into the oxygen-containing organic solvent (C) is unacceptable, the oxygen-containing organic solvent iJX<
By bringing C> into contact with water or an aqueous solution containing NH and HF, metal ions having a lower extraction and distribution ratio than niobium ions can be selectively transferred from the organic phase to the aqueous phase.

Next, the oxygen-containing organic solvent (C) is heated and evaporated or heated and distilled under normal pressure or reduced pressure.
The fourth step of the present invention consists of zero or more steps of regenerating niobium (niobium) and producing niobium halide.

In addition, since the organic solvent (C) that extracts and contains the niobium halogenated complex contains physically mixed water and/or H2O that is extracted and contains, in the fourth step, oxygen-containing The organic solvent (C) is brought into contact with a desiccant to dry the oxygen-containing organic solvent (C), and then heated and evaporated or heated and distilled under normal pressure or reduced pressure to obtain an extremely low oxygen content. It is also possible to produce a niobium halide and to regenerate the oxygen-containing organic solvent (C).

In the fifth step, the niobium halide obtained in the fourth step is brought into contact with gold, [Na, Mg, Ca, Zn and/or pb, or an alloy mainly composed of these, to reduce the niobium halide. This will give you niobium metal.

The gist of the present invention is that it contains mainly niobium and contains Ta and other metal impurities such as Fe, Mn, Ti.
, Sn, Sb, W, Ni, Co, Cu, K, Na, NH
=, Zn, Mo, Si, AI, Ca, ■, Li,
A mixture of H F and I-12S O in which ions such as Th coexist is added with one or more selected from the group consisting of chthon group, neutral phosphate ester group, alkyl amine group, and amide group. Two or more organic solvents (A) diluted with petroleum-based hydrocarbons are brought into contact to preferentially extract niobium ions and tantalum ions in the mixed solution.

TaF5-+H"+nOrg-HTaFs・norgN
bOF s2−+ 2 H”+nOrg−+H2NbO
F s ·norg extraction distribution ratio is Ta>Nb,
The extraction and distribution ratio of other metal impurity ions as mentioned above is Nb
Tantalum and niobium are preferentially extracted because the extraction distribution ratio is 10-3, which is even smaller than that of .

If the concentration of metal impurity ions to be co-extracted is unacceptable, the organic solvent (A) extracting and containing tantalum and niobium may be brought into contact with water or an aqueous solution containing NHL and HF to co-extract the metals. Impurity ions can be selectively transferred from the organic phase to the aqueous phase.

After removing metal impurity ions with a smaller extraction distribution ratio than niobium, the organic solvent (A) is brought into contact with water or an aqueous solution containing NH3 and HF again to back-extract the niobium and tantalum complex in the organic phase into the aqueous phase. .

Even if the aqueous solution used is the same in the co-extract washing operation and the niobium back-extraction operation, the flow rate ratio at the time of contact between the two solutions is different, so the total HFfi degree and niobium concentration on the water side change, resulting in a change in the niobium concentration. This can be carried out by taking advantage of the fact that the back extraction ratio of the aqueous solution changes, or by changing the NH concentration of the aqueous solution, which changes the free HF concentration on the water side after the two solutions come into contact.

H2NbOF5・nOrg"NHz"NH4F"HzO
→Nb0(OH)F<2-+2Nll<IIFz+nO
rg In the second step of the present invention, since tantalum ions also coexist in the niobium ion-containing liquid that is not back-extracted into the aqueous phase, ketone groups, neutral phosphate ester groups, alkyl Extraction and distribution by contacting with an organic solvent (B) or an adsorbent, which is one or more organic solvents selected from the group consisting of amines and amides, diluted with petroleum hydrocarbons. Removes tantalum ions with a large ratio. The adsorbent that can be used in this process adsorbs one or more extractants selected from the group of ketones, neutral phosphate esters, alkyl amines, and amides onto a porous solid. Or it can be obtained by crosslinking.

Such an adsorbent is described in Japanese Patent Publication No. 61-67000, for example, and for the purpose of adsorbing and removing trace amounts of metal ions in an aqueous solution, the adsorbent is used on the aqueous phase side as in a solvent extraction technique. Unlike methods in which a small amount of extractant is dissolved, this method provides an extremely efficient method.

Even if N bo F ,2- ions are once adsorbed on the adsorbent, when they combine with TaF, - ions having a large extraction/distribution ratio, Nb0F, 2- ions are pushed out and exchanged with TaF, - ions.

The method for regenerating the used adsorbent is the same as the back extraction method for organic solvents, and can be easily carried out by passing an aqueous solution containing NH, and )IF through the adsorbent.

Next, Nb gas or N H, OH or KOH is added to the Nb-containing aqueous solution from which Ta has been removed by back extraction to the aqueous phase side.
By adding and KF, a precipitate containing NH, + and F- or + and F- close to hydroxide is formed as shown in the following formula.

Nb0(011)F,”′÷4N+13+1(20+3
11+→Mho(Oll), F↓+38I1. FNH,
Before adding the gas, add a large amount of water to remove the HF in the aqueous solution.
If the concentration is diluted, niobium ions can be precipitated in a form similar to hydroxide.

Nb0(011)2F-+N11. +H20→Nb0(
011), ↓+NI1. The third step of the present invention consists of steps F and above.

In order to produce a niobium halide with even higher purity, impurities can be further removed by repeating the operations of the first to third steps one or more times.

Next, one or more acids selected from H2SO4, HCl, Hl, HBr, and HF are added to the niobium-containing back extract and the niobium-containing precipitate obtained in the second step to remove the precipitate. dissolve and adjust H+ ion concentration.

(NI+, ), Nb0(OH)F, ÷2HF+H2SO
,→NbF−÷21120+(8114)2SO,+H
“N11.Nb0 (011) 2F+511F+1/21
12SO, → NbF, -+31120+t/z (No,
)zso<÷211+ NbO(011) 2 +611C1→N b C1−
+ 411.0 + I+ "In the fourth step of the present invention, in the aqueous solution containing the niobium halide complex ion, a compound selected from the group consisting of the ester group, the ether group, the ketone group, and the alcohol group is added. By bringing one or more oxygen-containing organic solvents (C) into contact with each other, niobium is extracted as a halogenated complex as shown in the following formula.

NbFs-+H"+nOrg-+HNbF6・norg
NbC4's-+H''+nOrg→HNbC1s ・n
In the formula org, org represents the above-mentioned oxygen-containing organic solvent (C).

If the concentration of co-extracted metal impurity ions is unacceptable, the oxygen-containing organic solvent (C) containing the niobium halide complex is extracted with water, NH, and HF.
The co-extracted metal impurity ions can be selectively transferred from the organic phase to the aqueous phase by contacting with an aqueous solution containing .

Next, the oxygen-containing organic solvent (C) containing the extracted niobium halide complex is heated and heated at normal pressure or reduced pressure.
Niobium halide can be produced by evaporation or heating/distillation.

The regenerated oxygen-containing organic solvent (C) condensed in the condenser can be recycled again for niobium extraction.

In the fourth step, before heating and evaporating or heating and distilling the oxygen-containing organic solvent (C) containing niobium, if necessary, water physically mixed in the oxygen-containing organic solvent (C) is added. And/or unextracted R20 can be brought into contact with a desiccant to dry and remove it, thereby reducing the amount of oxygen contained in niobium halides such as NbFs and NbCl5 to an extremely small amount.

Depending on the temperature used for heating/evaporation or heating/distillation, inert gas may be introduced as appropriate to prevent oxidation of the oxygen-containing organic solvent (C) or to prevent oxidation of the niobium halide produced. Can be done.

The niobium halide produced in the fourth step is
Metallic niobium can be produced as shown in the following formula by bringing it into contact with a single metal selected from the group consisting of , Mg, Ca, Zn, and pb and/or an alloy mainly composed of these metals.

NbFs+5Na-Nb+5NaF NbC1,+ 2.5 M'; t→Nb+ 2.5 M
9CINbF s+ 2.5 Ca-+Nb+ 2.5
CaF 2NbC1s+2.5Zn-Nb+2.5Z
nC1゜NbFe alloy, 5Pb→Nb+2.5PbF2
Each metal (Na, Mg, Ca, Zn and p
As the element b) and alloys mainly composed of these, those in a red-hot state, gaseous state, or liquid state can be used.

Further, the niobium halide can also be supplied to the reaction process in a gaseous, liquid or solid form.

The reaction is carried out at 250° C. or higher, and can be carried out in an inert gas atmosphere such as Ar gas to suppress the formation of oxides, and a small amount of H2 gas can be mixed as appropriate.

In the present invention, starting materials mainly containing niobium and T
a and IF! Alternatively, an aqueous solution in which two or more types of metal impurity ions coexist can be prepared as follows.

-m, dissolve resources such as tankrite, columbite, struberite, tin slag, NbTaFe alloy, and NbFe alloy, or electronic material waste such as defective superconducting wires with hydrofluoric acid alone or a mixed acid such as hydrofluoric acid and sulfuric acid. It can be produced by extracting and separating Ta ions in the resulting solution.

Organic solvents (A) and (B) that can be used in the present invention
) is selected from the following group:

■ Ketone group: □・〉0=0 (In the formula, R and R' represent an alkyl group or an aryl group,
ketones having 3 to 18 carbon atoms), methyl isobutyl ketone, cyclohexanone, methyl propyl ketone and similar ketones.

(2) Group of neutral phosphoric acid esters: (In the formula, R represents an alkyl group, and those having 4 to 18 carbon atoms are used).

(2) Alkylamine group: Primary to tertiary amines represented by RNH-5R2NH- and R3NH (in the formula, R represents an alkyl group, and those having 4 to 24 carbon atoms are used).

■Amide group: (In the formula, R represents an alkyl group, and the number of carbon atoms is 4 to 25
).

The diluent for the organic solvent used in the present invention is a petroleum hydrocarbon, and aromatic or aliphatic diluents can be used. Of course, mixtures of these can also be used.

There are 8 extractants! Melt! (A) is selected from each of the above groups, and may be one type or two or more types, but in the case of two or more types, the mixing ratio depends on the properties of the target aqueous solution, the types of impurities, and their coexistence ratio. can be determined.

The concentration of the extractant is also the same, and is generally adjusted to 2 to 100% (volume ratio).

The oxygen-containing organic solvent (C) used in the present invention is selected from the following group.

■ Ketone group: R 8 〉 0 = 0 (wherein R and R' represent an alkyl group or an aryl group,
ketones having 3 to 18 carbon atoms), methyl isobutyl ketone, cyclohexanone, methyl propyl ketone and similar ketones.

■Ester group: selected from phosphate esters and acetate esters.

■ Group of ethers: Can be selected from aliphatic single ethers, aliphatic hybrid ethers, aliphatic unsaturated ethers and aromatic ethers.

■Alcohol group: Various types with 4 to 22 carbon atoms (normal, secondary, tertiary)
alcohol.

The solvent used in the present invention for washing the solid by-product ammonium halide is selected from the following group.

■For petroleum hydrocarbons, the boiling point of petroleum ether, petroleum benzene, hexon, etc. is below 100℃, and the surface tension is 20℃.
Includes 30 dynes/cva or less at °C.

■For aromatic hydrocarbons, benzene etc. are used.

The desiccant used in the present invention is used to remove H2O extracted together with the water physically mixed in the oxygen-containing organic solvent (C) and the niobium halogenated complex, and dry it. Molecular sheep such as anhydrous calcium chloride, anhydrous magnesium sulfate, anhydrous magnesium chloride, anhydrous potassium chloride, activated alumina, magnesium perchlorate, phosphorus pentoxide, anhydrous potassium carbonate, barium oxide, and synthetic zeolites can be used.

The drying step, which is an optional step of the present invention, is an oxygen-containing organic solvent (C
) to reduce the oxygen content in the final product, the niobium halide, to a minimum by removing the extracted H z O together with the water and the niobium halide complex that are physically present in the niobium halide. It is a process. However, a certain amount of water present in the oxygen-containing organic solvent (C) can also be removed in the next step of heating and evaporating or heating and distilling at normal pressure or reduced pressure. In addition, since this drying process brings the oxygen-containing organic solvent (C) into contact with the above-mentioned substances, some impurities may be mixed into the oxygen-containing organic solvent (C) instead of removing water. Therefore, it is desirable to carry out the drying process in consideration of the desired oxygen content and impurity content of the final product, niobium halide.

The inert gas used in the present invention is N2 gas or Ar gas, and is used to prevent oxidation of the oxygen-containing organic solvent (C) when heating/evaporating or heating/distilling the oxygen-containing organic solvent (C), It can be used so that the generated tantalum halide does not change in quality.

Furthermore, niobium halide is treated with metal Na, MI? at a temperature of 250'C or higher. , Ca, Zn and PB, and can be suitably used in the process of producing metallic niobium is Ar gas. Gaseous reducing metals and gaseous niobium halides are usually introduced into the equipment along with gas.

The metals used as reducing agents in the present invention are Na, My, and Ca.
, Pb and Zn, and/or alloys based on them, which can be used in gaseous, liquid and red-hot solid forms.

Further, the niobium halide used in the reduction step can be used in any of gas, liquid, and solid forms.

The present invention will be described below based on the drawings, but it should be understood that the present invention is not limited thereto.

FIG. 1 is a flow sheet showing the basic type of operation of the present invention, which contains mainly niobium and Ta and one or more metal impurities such as Fe, Mn, Ti, Sn, Sb,
W, Ni, Co, Cu, Na, N H4, Zn,
A mixed solution of hydrofluoric acid and sulfuric acid in which ions such as Mo, Si, AI, Ca, V, Li, and Th coexist is led to the niobium extraction step (A), and all I!I! By contacting with the solvent (A), niobium and tantalum in the mixture are preferentially extracted as a fluoride complex.

Next, if the concentration of metal impurity ions that are co-extracted in small amounts into the organic solvent (A) that extracts and contains niobium is unacceptable, a cleaning step (B) is performed to selectively remove these impurities.
), the organic solvent (A) is introduced into water or N H3 and HF.
Next, the organic solvent (A) is brought into contact with the aqueous solution (A) containing the metal impurity ions to transfer the metal impurity ions from the organic phase to the aqueous phase.
is led to the niobium back extraction step (C), and water or N H3
By contacting with a solution (b) containing niobium and HF or ni and HF, the niobium fluoride complex is transferred from the organic phase to the aqueous phase and the organic solvent (A) is regenerated. The regenerated organic solvent (A) is recycled to the niobium extraction step (A).

Since the niobium transferred to the aqueous phase side contains tantalum, the tantalum extraction step (D
), one or more organic solvents selected from the group consisting of ketones, neutral phosphate esters, amines, and amides, diluted with petroleum hydrocarbons. By contacting with the organic solvent (B) or the above-mentioned adsorbent, Ta is extracted/removed or adsorbed/removed preferentially than the back extraction solution.

Next, the niobium back extract from which tantalum has been removed is neutralized and filtered (E) 4. :Niobium, N by adding H3 and NH4OH or KOH and KF
A precipitate containing H4'' and F- or niobium, K1 and F- is produced.

Next, the reverse extraction solution containing the niobium fluoride complex obtained in the tantalum extraction step (D) or the neutralization/filtration step (
In the step (F) of dissolving the niobium-containing precipitate obtained in E) and adjusting the H+ ion concentration, H2SO, HCl, HF
, HI and/or HB r(d) to dissolve and adjust the H+ ion concentration to convert N[lOF,'- ions to NbF,- ions, then in the extraction step (G), By contacting with an oxygen-containing organic solvent (C), N
The niobium halogenated complex in the bF6- ion-containing solution is extracted into an oxygen-containing organic solvent (C).

Next, the oxygen-containing organic solvent (C) is heated and evaporated or heated and
The oxygen-containing organic solvent (C) is regenerated by introducing it into the distillation step (H) and heating and evaporating or heating and distilling it under normal pressure or reduced pressure while introducing an appropriate inert gas, and at the same time regenerating the niobium halide. (J) is produced.

Metallic niobium (M
>, a reducing agent, and a halogen (N) is produced.

Figure 2 shows the method for producing niobium metal, which is the same as the flow sheet shown in Figure 1, except that niobium from the extraction step (G) is extracted and the oxygen-containing organic solvent (C) containing it is added to the desiccant). It incorporates a drying step (K) consisting of contacting with.

[Implementation example] The present invention will be further explained with reference to Examples below.

and 11 The niobium-containing liquid used in the following tests was prepared by mixing tantalite and columbite and dissolving them in a mixed acid of HF and H2SO, selectively extracting tantalum ions from the solution, and then adding H,S It was prepared by adding ○. The composition of the obtained niobium-containing liquid is shown in Table 1 below.

No. 1--161 (Unit: g/l>Nb2O56
2,7 Ta20. 0.06 Fe 8 , I Mn 5.9 Ti 1.6 Sn 0.4 Sb O, 07 W 0.03 Si 3.7 An Q, 9 H2S0. 380.4 HP 91.3 Using the above-mentioned niobium-containing liquid, extraction conditions ○/A = 1/
1. Using the same conditions of shaking time of 5 minutes, the extraction distribution ratio was determined using the four types of extractants shown in Table 2. The results obtained are listed in Table 2 below.

The extraction distribution ratio (DIE) is calculated by the following formula.

+r2so, as the x degree increases, the extraction and distribution ratio of metal impurity ions increases and separation from Nbz○ becomes difficult, so H2SO423 degree becomes important.

Gold...4. As shown in Table 2, in addition to niobium and tantalum, trace amounts of metal impurity ions are extracted. O/A to solvent
Metal impurities were removed by contacting with a solution containing 0.2 mol/l of N 2 H and F at a ratio of 10/1. The results obtained are listed in Table 3 below.

Although the cleaning results for T 1120 s are not listed in Table 3 above, the tantalum-containing Ji0.03y/l before cleaning
However, after washing, it became 0.025 g/l, and there was almost no difference.

In addition, in the actual device, since the cleaning operation is carried out by multistage countercurrent contact, metal impurity ions with a smaller extraction and distribution ratio than NbzOs move to the aqueous phase, and Nb2O and TII are transferred to the organic phase.
Only 20 s remain.

Nip ・ Next, a 2.0 mol/1 NH,F aqueous solution was added to Nb2O.

A test was conducted in which Nb2O in the organic phase was extracted and brought into contact with an organic solvent containing TlI2O3 and Nb2O.

The results obtained are listed in Table 4.

As shown in the aqueous phase of Table 4, since the content of Nb, O, and TlI2O3 in the back-extraction solution is about 1/1000, it is necessary to selectively remove T a 20 s.

TaO from NbO5 - In order to remove trace amounts of metal ions, it is preferable to use an extractant with low solubility.

In this test, Ta205 was removed using the solvents or adsorbents listed in Table 5 below. The extraction conditions using an organic solvent are O/A=1/10. The shaking time was 5 minutes. In addition, the adsorbent has a weight ratio of 10% to the porous particles.
The Nb0F,'- ions were extracted in advance from the organic solvent.

[-2 sets (unit: ti/1> lJI Nb2O5Ta205 IIFN
lls 112S04 pre-extraction solution 76.3 0.0
8 110.2 34.1 <0.00130 STOP
O"ri17shishi71.9 0.006 105.
7 34.1 <0.001101 TOA ten a'
i> 72.1 0.002 101.2
34.0 <o, oot adsorbent 76.2 <
0.001 118.7 34.1 <0.001 It should be understood that in the actual device, the Ta205 concentration can be lowered even lower than the one listed in Table 5 because the extraction operation is a self-flow multi-stage contact.

Add 10% NH to the Nb2o5 back extract after removing Ta205 from 1.
3-containing solution was added to neutralize the reverse extraction solution, the resulting precipitate was dried, and the results of analysis are listed in Table 6.

=6 (unit: weight%) Nb20. 73.18 T ax Os < O, OOIFe
<0.001 Mn <0.001 Ti <0.001 Sn <0.001 W <0.001 NH,8,59 HF 3.28 If the analysis results in Table 6 do not satisfy the desired product purity, , without redissolving or neutralizing the back extract with H2SO
, add it! (It should be understood that the purity of Nb2O can be improved by increasing the ion concentration and repeating the above operations one or more times.

Precipitates of which an example is shown in Table 6 or T shown in Table 5
A solution with the composition shown in Table 7 was prepared by adding H2S O4 and HF or ■]2S04 and HCl to the solution from which a2O was removed, and used as a raw material for producing niobium chloride and fluoride complexes. .

21-21-1 retreat, (unit g/1)7iiLjL(
Jin I N b205 143.6 117.
3N H, 17,38,4 HF 350.3 2.1HC
1264,8 H2S O+ 256.8 '15
100% cyclohexanone and 100% methyl isobutyl ketone were used for -extraction of Nb and O5 with 0°0 element'C. The extraction conditions were O/A=115 and shaking time of 5 minutes, and the results obtained are listed in Table 8.

Daiichi 8-11 Shishie (Unit: g/l) Organic solvent used Nidiclohexanone Nb2O5Ta2es IIF llCl N
Il* 112SO-organic phase 62.1 <0.001
53.3-- <0.1 0.2 aqueous phase 131. I
N, D, 297.1--17.3 254.1
Organic solvent used: methyl isobutyl ketone NbzOs
Ta205 IIFIIC1NII* lI
2SO4 Aritachi phase 54.4 <0.001 0.6 8
5.9 <0.1 <0.01 aqueous phase 106.4 N
,D, 6.1 247.6 8.4150.4Fe
, Mn, Ti, Si, Sb, Co, Cu, Ca, W, K
, Na, Zn, and AN extraction amounts are all O,
It was less than 0O1f/1.

However, if a large number of metal impurity ions are extracted inadvertently in an actual device, water or a solution containing NH, and HP is transferred to the aqueous phase as in the first cleaning step (B), and the organic solvent is removed. It is necessary to perform the operation so that only niobium ions remain inside.

Chiku・Mat・Has mouth fever・2・ Ar gas was introduced into the experimental container to expel the atmosphere, and heating/evaporation or heating/distillation tests were performed.

The oxygen-containing organic solvent used was one in which water droplets were not visible to the naked eye. The results obtained are listed in Table 9 below.

Kanbe J. [Reduction tests were conducted using the niobium halide prepared as described above. The results obtained are listed in Table 10.

[Effects of the invention] If niobium metal is produced by the method of the present invention, the process will be simplified compared to conventional methods, there will be no restrictions on raw materials, and high-quality niobium metal can be used with an energy-saving manufacturing method. .

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing a basic type of operation of the present invention, and FIG. 2 is a flow sheet showing an operation in which a drying step is added to the basic type operation described in FIG. In the figure: A... Niobium extraction process; B... Washing process; C... Back extraction process; D... Tantalum extraction process; E... Neutralization/filtration process; F... Dissolution/ G... Extraction process; H... Heating/evaporation or heating/distillation process; J... Niobium halide K... Drying process; S... Reduction process; M ...metallic niobium; N...a combination of a reducing agent and a halogen; a...water or an aqueous solution containing NH3 and HF; solution containing; BarN H3 and NH4OHMari!i K OH and K
F. :・,・H2S O4, H(1, HF, HI and/or HBr; E...Inert gas; F...Drying agent; T...Reducing agent.

Claims (1)

[Claims] 1. A method for producing niobium metal from a mixed solution of hydrofluoric acid and sulfuric acid that mainly contains niobium and in which one or more metal impurity ions including tantalum coexist: (a) The mixed liquid contains one or more organic solvents selected from the group of ketones, the group of neutral phosphate esters, the group of alkylamines, and the group of amides, and is an organic solvent diluted with a petroleum hydrocarbon. Niobium and tantalum are preferentially extracted from the mixture by contacting the solvent (A), and the organic solvent (A) is mixed with water, NH_3 and HF, or K^+ and HF.
Extracted into organic solvent (A) by contacting with an aqueous solution containing
A first step of back-extracting the contained niobium and tantalum to the aqueous solution side and regenerating the organic solvent (A); (b) A group of ketones, One or more organic solvents selected from the group of neutral phosphate esters, the group of alkyl amines, and the group of amides, and an organic solvent (B) diluted with a petroleum hydrocarbon or an adsorbent. A second step of preferentially extracting/removing or adsorbing/removing tantalum in the aqueous solution by contacting it; (c) adding NH_3 gas and NH_4OH or KOH and KF to the niobium-containing aqueous solution from which the back-extracted tantalum ions have been removed; , niobium, F^- and NH_4
a third step consisting of producing a precipitate containing ^+ or niobium, F^- and K^+; (d) the niobium-containing back extract obtained in the second step and/or in the third step; H_2SO_4 in the produced precipitate
, HCl, HF, HI and HBr.
A seed or acids are added to dissolve the precipitate and H
After adjusting the ion concentration, by contacting with one or more oxygen-containing organic solvents (C) selected from the group consisting of esters, ethers, ketones, and alcohols. Extracting the niobium ions in the aqueous solution as a metal halide complex into an oxygen-containing organic solvent (C),
Next, a fourth step of regenerating the oxygen-containing organic solvent (C) and producing a niobium halide by heating/evaporating or heating/distilling under normal pressure or reduced pressure; and (e) in the fourth step. Production of niobium metal, characterized by a fifth step of making niobium metal by contacting the obtained niobium halide with elemental metals Na, Ca, Pb, and Zn and/or alloys mainly composed of these metals. Method. 2. Extract the niobium halogenated complex obtained in the fourth step and bring the oxygen-containing organic solvent (C) containing it into contact with a desiccant to physically contain it in the oxygen-containing organic solvent (C). The manufacturing method according to claim 1, which comprises removing and drying the water contained therein and the H_2O contained therein. 3. Hydrofluoric acid and sulfuric acid are added to the niobium-containing reverse extraction solution obtained in the second step or the precipitate produced in the third step to dissolve the precipitate and reduce the H^+ ion concentration. The manufacturing method according to claim 1, wherein the purity of the niobium halide is improved by repeating the operations from the first step to the third step one or more times after the adjustment. 4. In order to remove trace amounts of tantalum ions contained in the niobium-containing liquid in the second step, an extractant selected from each group consisting of the alkyl chiamine group, the neutral phosphate ester group, and the acetamide group is applied to porous particles. The manufacturing method according to claim 1, which uses an adsorbent or a crosslinked adsorbent. 5. Extract and add niobium halogenated complex to the organic solvent (A) and oxygen-containing organic solvent (C) containing water or NH
The manufacturing method according to claim 1, wherein one or more metal impurity ions are selectively removed by contacting a solution containing 3 and HF.