Process for deep antimony and tantalum removal from niobium-containing solutions

Abstract

This invention discloses a method for deep removal of antimony and tantalum from niobium-containing solutions, belonging to the field of rare metal purification technology. The method involves first oxidizing and complexing a niobium solution containing antimony, tantalum, and fluorine with an inorganic peroxide, followed by acid adjustment and extraction to remove impurities, yielding a purified niobium-containing solution. This method can achieve deep removal of trace impurities of antimony and tantalum from niobium solutions, resulting in a high-purity niobium solution that readily yields 4N-grade high-purity niobium oxide products. Compared to previous niobium removal processes, this method offers advantages such as a shorter process flow, simpler operation, lower reagent costs, no pollution, higher removal efficiency, and better product quality, making it valuable for industrial application.

Description

Technical Field

[0001] This invention relates to a method for removing impurities from a niobium-containing solution, and more particularly to a method for deep removal of antimony and tantalum from a niobium-containing solution. Specifically, it relates to a method for deep removal of antimony and tantalum impurities from a niobium solution produced in the back-extraction stage during a tantalum-niobium metallurgical process, belonging to the field of rare metal purification technology. Background Technology

[0002] Niobium, with its advantages of high melting point, corrosion resistance, deformation resistance, and good thermal conductivity, is widely used in electronics, chemical industry, aerospace, superconductivity, optics, and medical fields. Niobium pentoxide (hereinafter referred to as niobium oxide, Nb2O5) is an important raw material for the production of metallic niobium and a basic raw material for nickel niobate single crystals, special optical glass, high-frequency and low-frequency capacitors, piezoelectric ceramic components, and catalysts. For example, niobium oxide is added to glass lenses to make them lighter and thinner, exhibiting greater elasticity, resulting in better performance and smaller components in digital cameras and mirrorless camera systems; niobium oxide provides precise frequency control, optimized selectivity, and reduced distortion in surface acoustic wave (SAW) filters used in mobile devices such as smartphones, tablets, laptops, or satellite positioning applications; spherical niobium oxide is used as a spray powder, a dopant in multilayer ceramic capacitors (MLCCs), barium titanate dielectrics / potassium sodium niobate (KNN) lead-free piezoelectric materials, and a sputtering target for the production of display coatings. With the booming development of industries such as 5G, new energy vehicles, high-end electronic equipment, and aerospace, more and more industries are placing higher demands on the purity of niobium oxide. This demand for material purity has also promoted the continuous development of high-purity material preparation technologies. Based on different usage requirements and chemical compositions, the non-ferrous metals industry standard YS / T548-2007 classifies niobium oxide products into four grades: FNb2O5-048, FNb2O5-045, FNb2O5-04, and FNb2O5-035. The tantalum (Ta) impurity content (mass fraction) is required to be no greater than 0.0003%, 0.0005%, 0.001%, and 0.002%, respectively, while the antimony (Sb) content is required to be no greater than 0.0002%, 0.0006%, and 0.001%, respectively. Overall, the content of impurities such as Ta and Sb (excluding fluorine and silicon) is a key consideration for niobium oxide products and is crucial in determining their grade.

[0003] Chinese Patent (Publication No.: CN102358918A) discloses a method for removing antimony from ultra-high purity tantalum pentoxide and niobium pentoxide. This method involves using D296 resin to adsorb tantalum and D290 resin to adsorb niobium in a sec-octanol system, respectively, thereby removing antimony from the tantalum and niobium solutions. Chinese Patent (Publication No.: CN103408070A) discloses a process for removing antimony from niobium-tantalite ore to prepare high-purity niobium oxide. First, the niobium-tantalite ore is leached with 36% hydrochloric acid to remove most of the antimony. Then, tantalum and niobium are decomposed with sulfuric acid-hydrofluoric acid, and hydrazine solution is added to reduce high-valence antimony in the leaching solution. Finally, high-purity niobium oxide is obtained through a process of "sec-octanol extraction-sec-niobium-neutralization-calcination". Chinese Patent (Publication No.: CN104445406A) discloses a method for preparing ultra-high purity niobium oxide. Using a fluoroniobic acid solution as raw material, after acidity adjustment, the solution undergoes extraction with 2-octanol, acid washing, and back-extraction to obtain an ultra-high purity fluoroniobic acid solution. Liquid ammonia is added for precipitation, and the solution is washed with ammonia-containing hot water at 60-70℃ to obtain a niobium hydroxide filter cake. Finally, the solution is calcined in steps to obtain the ultra-high purity niobium oxide product. Chinese Patent (Publication No.: CN104477993A) discloses a production method for preparing high-purity niobium oxide using a high-antimony niobium solution. This method involves adding a saturated ammonium sulfate solution to the high-antimony niobium solution, controlling the niobium concentration to be ≥70 g / L and the acidity to be ≥3N. Then, the acidified niobium solution is extracted with 2-octanol and back-extracted to prepare a pure niobium solution. After neutralization and precipitation, the solution is calcined at 900-1000℃ to obtain high-purity niobium oxide. Chinese Patent (Publication No.: CN108862384B) discloses a method for preparing low-antimony niobium oxide / tantalum oxide. First, antimony in the solution is reduced to a +3 low valence state using a carboxylic acid reducing agent. Then, triethanolamine or sulfide ethanolamine is added as a complexing agent to generate a stable antimony complex. Following neutralization with alkali, washing, drying, and calcination, efficient separation of niobium or tantalum products from antimony is achieved. Similarly, Chinese Patent (Publication No.: CN 109097572A) discloses a method for separating TaSb and NbSb by adding a water-soluble antimony complexing agent to an aqueous solution of fluoroniobic acid / fluorotantalic acid, followed by ammonia neutralization, precipitation, washing, and filtration. Chinese Patent (Publication No.: CN118389834A) discloses a method for deep purification of tantalum-niobium metallurgical solutions. Through oxidation-acidification-foaming impurity removal, difficult-to-separate impurities are captured under medium-acidity conditions. Then, through acidification and niobium extraction, the target metal is separated under high acidity conditions, ultimately yielding a clean anti-niobium solution. In general, existing technical routes are cumbersome and complex in operation. They mainly obtain pure niobium liquid by repeatedly extracting / adsorbing the main element niobium. However, the concentration of niobium liquid in metallurgy can generally reach 60~90g / L. The extraction process will result in a large consumption of organic phase / adsorption resin, increasing energy consumption and reducing impurity removal efficiency. Some patented technologies also require additional expensive reducing agents, complexing agents and foam stabilizers, which are difficult to recycle and reuse. This not only greatly increases the cost of impurity removal, but also easily causes pollution and seriously affects product quality. Summary of the Invention

[0004] To address the technical problems of difficulty and high cost in separating and removing impurities such as antimony and tantalum from niobium-containing solutions using existing technologies, the present invention aims to propose a method for deep removal of antimony and tantalum from niobium-containing solutions. This method can improve the removal efficiency of antimony and tantalum, shorten the separation process, reduce costs and pollution, and facilitate the subsequent acquisition of high-purity niobium pentoxide.

[0005] To achieve the above-mentioned technical objectives, the present invention provides a method for deep removal of antimony and tantalum from a niobium-containing solution. The method involves first oxidizing and complexing the niobium solution containing antimony, tantalum, and fluorine with an inorganic peroxide, followed by acid adjustment and extraction to remove impurities, thereby obtaining a niobium-containing purified solution.

[0006] The key to this invention lies in the oxidative complexation treatment of a niobium solution containing antimony, tantalum, and fluorine using inorganic peroxides, utilizing peroxide ions to oxidize and complex the niobium solution containing NbOF5. 2- Niobium in ionic form is selectively converted to Nb(O2)F5 2- (pH≤1), Nb(O2)2F4 3- (1≤pH≤5) ions, which are difficult to extract with conventional oxygen-containing extractants, while tantalum and antimony in niobium solutions mainly exist in the form of fluoride complex anions, which are easily extracted by conventional oxygen-containing extractants. This facilitates the extraction and separation of antimony, tantalum, and niobium. More specifically, due to TaF7 2- TaF6 - SbF7 2- SbF6 - The differences in ion size and charge-to-mass ratio between niobium and fluoride ions result in a greater affinity between oxygen-containing extractants and the fluoride complexes of tantalum and antimony than for niobium fluoride ions. Existing technologies primarily utilize this characteristic to achieve the extraction and separation of tantalum and antimony from niobium solutions using oxygen-containing extractants. However, existing oxygen-containing extractants still cannot achieve deep separation of tantalum and antimony in niobium solutions. The key to this invention lies in using inorganic peroxides to convert niobium fluoride ions into niobium fluoride peroxide anions. Since the extraction ability of oxygen-containing extractants for niobium fluoride peroxide anions is lower than that for niobium fluoride ions, this further enhances the extraction and separation capabilities of oxygen-containing extractants for tantalum, antimony, and niobium, improving the extraction and separation efficiency. Simultaneously, given that antimony in typical tantalum-niobium concentrates may exist at valences of +3 and +5, the added peroxide ions can, to some extent, oxidize +3 antimony to +5. The fluoride complex anions of +5 antimony are more easily extracted than +3 antimony, further increasing the antimony extraction rate. In summary, this invention alters the form of niobium ions in a niobium solution through an oxidative complexation reaction, which is more conducive to the extraction and separation of tantalum, antimony, and niobium.

[0007] As a preferred embodiment, the niobium solution contains 60-70 g / L Nb, 0.01-0.12 g / L Sb, 0.2-0.4 g / L Ta, 1-6 mol / L hydrogen ions, and 1-4 mol / L fluoride ions. Specifically, the niobium solution of this invention is exemplified by the niobium solution produced in the back-extraction stage of a tantalum-niobium metallurgical production process. Under acidic conditions and in the presence of fluoride ions, the main forms of niobium, tantalum, and antimony in the niobium solution are NbOF5, respectively. 2- TaF7 2- TaF6 - SbF7 2- SbF6 - The extraction of tantalum and niobium is generally considered to be a "pseudo" salt extraction. Regardless of whether the extractant is a ketone, alcohol, amide, phosphine oxide, or phosphonate ester, they are all oxygen-containing extractants. These oxygen-containing extractants can attract positively charged hydrogen ions or hydrated hydrogen ions to form "pseudo" cations, which then combine with complex anions such as tantalum, niobium, and antimony in the aqueous phase via electrostatic attraction to form "pseudo" salts, thus achieving extraction. However, when peroxide ions are introduced into the niobium solution, the niobium oxyfluorine complex anion is selectively converted into a niobium fluorine peroxide complex anion, which is more difficult to extract with oxygen-containing extractants, such as Nb(O2)F5. 2- (pH≤1), Nb(O2)2F4 3- (1≤pH≤5) plasma, which is more conducive to the extraction and separation of niobium from tantalum and antimony.

[0008] As a preferred embodiment, the inorganic peroxide includes at least one of hydrogen peroxide, sodium peroxide, and barium peroxide. The preferred inorganic peroxide primarily provides peroxide ions in the solution system to achieve NbOF5… 2- The oxidative complexation of ions forms Nb(O2)F5, which is more difficult to extract with oxygen-containing extractants. 2- Nb(O2)2F4 3- Plasma. A further preferred inorganic peroxide is hydrogen peroxide, which avoids the introduction of impurity metal ions. Simultaneously, under acidic conditions, these inorganic peroxides exhibit oxidizing properties, capable of oxidizing trivalent antimony, thereby improving the extraction efficiency of antimony by oxygen-containing extractants.

[0009] As a preferred embodiment, the amount of inorganic peroxide added to the niobium solution is 2-20 g / L. More preferably, the amount of inorganic peroxide added to the niobium solution is 10-16 g / L. If the amount of inorganic peroxide added is too low, it will be difficult for the niobium fluoride oxide anion to be completely converted into the niobium fluoride peroxide oxide anion.

[0010] As a preferred embodiment, the oxidative complexation conditions are: a temperature of 5~40℃ and a time of 0.5~2h. Under these preferred oxidative complexation conditions, niobium fluoride oxide anions can be fully converted into niobium fluoride peroxide anions.

[0011] As a preferred embodiment, the acid-adjusting reagent used in the acid-adjusting process includes at least one selected from hydrofluoric acid, sulfuric acid, nitric acid, and hydrochloric acid. As a preferred embodiment, the acid concentration of the solution system is adjusted to 6-10 mol / L during the acid-adjusting process. The acid-adjusting reagent is further preferably a combination of sulfuric acid and hydrofluoric acid. During the acid-adjusting process, the sulfuric acid concentration in the solution system is adjusted to 1-6 mol / L, and the hydrofluoric acid concentration is between 1-6 mol / L. The sulfuric acid concentration is further preferably 4-6 mol / L, and the hydrofluoric acid concentration is further preferably 3-5 mol / L. This preferred acid system facilitates the extraction and separation of fluorine complex anions of tantalum and antimony by oxygen-containing extractants.

[0012] As a preferred embodiment, the extractant used in the extraction process includes at least one of ketone extractants, alcohol extractants, amide extractants, phosphine oxide extractants, and phosphonate extractants. As a more preferred embodiment, the ketone extractant includes at least one of methyl isobutyl ketone and methyl isopropyl ketone. As a more preferred embodiment, the alcohol extractant includes at least one of 2-octanol, isooctanol, and pentanol. As a more preferred embodiment, the amide extractant includes at least one of N,N-dimethylheptylacetamide, N,N-di-n-mixed acetamide, and N-phenyl-N-octylacetamide. As a more preferred embodiment, the phosphine oxide extractant includes at least one of tributylphosphine oxide, trioctylphosphine oxide, and trialkylphosphine oxide. As a preferred embodiment, the phosphonate extractant includes at least one of tributyl phosphate, trioctyl phosphate, and dibutyl butylphosphonate. The preferred extractants are all conventional extractants used in fluorine-containing solution systems for extracting tantalum and antimony.

[0013] As a preferred embodiment, the extraction process employs a multi-stage extraction method with 1 to 7 extraction stages. The volume percentage of the extractant in the organic phase is not less than 20%, the O / W phase volume ratio is 1.3 to 0.95:1, the extraction temperature is 0 to 40°C, and the extraction time is 5 to 10 minutes. The number of extraction stages is further preferably 3 to 6.

[0014] As a preferred embodiment, the extractable organic phase includes a diluent; the diluent includes at least one of sulfonated kerosene, 260# solvent oil, paraffin oil, and n-octane; the volume percentage of the diluent in the extractable organic phase is less than 20%.

[0015] The niobium-containing solution of the present invention is subjected to deep antimony and tantalum removal to obtain a high-purity niobium-containing purification solution, and then conventional neutralization precipitation and roasting are carried out to prepare a high-purity niobium oxide product. Preferably, the alkaline solution reagent used for neutralization precipitation includes at least one of sodium hydroxide, potassium hydroxide, and ammonia water, and ammonia water is further preferred. The pH value of the neutralization precipitation is controlled between 7 and 11, and further preferably 8 < pH < 9. Preferably, the roasting temperature is controlled between 700 and 1000 °C, the further preferred roasting temperature is 850 °C, and the roasting time is preferably 4 to 6 hours, and further preferably 5 hours.

[0016] Compared with the prior art, the technical solution of the present invention has the following obvious technical advantages:

[0017] (1) The present invention can achieve deep removal of antimony and tantalum in the niobium solution, and the obtained clean niobium solution can be used to prepare 4N-grade high-purity niobium oxide products.

[0018] (2) Before extraction and impurity removal, the present invention does not need to add special reagents such as hydrazine, triethanolamine or sulfurized ethanolamine, antimony organic complexing agent, foam stabilizer, etc., only consumes part of the peroxide ions, has low cost, good operating environment, and is conducive to improving product quality.

[0019] (3) In the extraction and impurity removal process of the present invention, mainly impurities antimony and tantalum in the niobium solution are extracted, and the separation efficiency is high, the amount of extractant used is small, and the equipment investment is small; compared with the ion exchange method, the mass transfer rate in the extraction process is fast, the wastewater discharge is reduced, and it is conducive to environmental protection.

[0020] (4) The extraction and separation process flow of the present invention is short, easy to realize continuous operation, and easy to realize industrialization. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a process flow diagram for deep antimony and tantalum removal in the niobium-containing solution of the present invention and the preparation of high-purity niobium oxide. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The content of the present invention will be specifically described below through examples. It should be noted that these examples are only for better understanding the content of the present invention rather than further limiting the protection scope of the present invention.

[0023] The following examples adopt Figure 1 the described process flow diagram for implementation.

[0024] Example 1

[0025] First, 1.2 times the theoretical amount of hydrogen peroxide was added to a niobic acid solution (Nb 68.20 g / L, Ta 3.02 mg / L, Sb 4.15 mg / L, hydrogen ion concentration 5.60 mol / L, fluoride ion concentration 2.02 mol / L) containing tantalum and antimony impurities in the back-extraction section provided by a tantalum and niobium smelter for oxidation / complexation, with a total added amount of 16.74 g / L. Then, the niobium solution was acidified using a combination of sulfuric acid and hydrofluoric acid solutions, controlling the sulfuric acid concentration at 4.62 mol / L and the hydrofluoric acid concentration at 4.52 mol / L. Next, a mixed extraction system of tributyl phosphate and 2-octanol (extractant component accounting for 80% by volume) was selected and mixed with the acidified niobium extraction solution in a separatory funnel at a volume ratio of 1:1 for organic phase / aqueous phase. Five-stage countercurrent extraction was carried out, with the shaking time controlled at 10 min, to obtain a clean raffinate niobium solution after tantalum and antimony removal. The antimony removal rate was 94%, the tantalum removal rate was as high as 98%, and the niobium loss rate was about 5%. Ammonia was then slowly added to the clean niobium solution while continuously stirring. The pH value at the precipitation endpoint was controlled at around 8.5. After a large amount of white solid precipitated, the solution was filtered and vacuum dried. The completely dried niobium solid was then oxidized and calcined at 850°C for 6 hours to obtain high-purity niobium oxide. The antimony content in the niobium oxide was tested to be less than 3 ppm and the tantalum content was less than 2 ppm, meeting the requirements for 4N grade high-purity niobium oxide products.

[0026] Example 2

[0027] A niobic acid solution containing tantalum and antimony impurities (Nb 68.20 g / L, Ta 3.02 mg / L, Sb 4.15 mg / L, hydrogen ion concentration 5.60 mol / L, fluoride ion concentration 2.02 mol / L) was supplied to a tantalum and niobium smelter. 1.05 times the theoretical amount of hydrogen peroxide was added for oxidation / complexation, with a total added amount of 14.65 g / L. Then, a combination of sulfuric acid and hydrofluoric acid solutions was used to adjust the niobium solution, controlling the sulfuric acid concentration at 4.01 mol / L and the hydrofluoric acid concentration at 4.42 mol / L. Next, a methyl isobutyl ketone (MIBK) extraction system (100% extractant by volume) was used to mix the acidified niobium extraction solution with the organic phase / aqueous phase at a volume ratio of 0.95:1.0 in a separatory funnel. Five stages of countercurrent extraction were performed, with shaking time controlled at 10 min, to obtain a clean niobium residue solution after tantalum and antimony removal. The antimony removal rate was 92%, the tantalum removal rate was 96.7%, and the niobium loss rate was approximately 6.5%. Ammonia was then slowly added to the clean niobium solution with continuous stirring, controlling the pH at the precipitation endpoint to approximately 9.0. After a large amount of white solid precipitated, the solution was filtered and vacuum dried. The completely dried niobium solid was then calcined at 850℃ for 6 hours to obtain a high-purity niobium oxide product. Testing showed that the antimony content in the niobium oxide was less than 2.5 ppm and the tantalum content was less than 2 ppm, meeting the requirements for 4N grade high-purity niobium oxide products.

[0028] Example 3

[0029] Similarly, the niobic acid solution containing tantalum and antimony impurities (Nb 68.20 g / L, Ta 3.02 mg / L, Sb 4.15 mg / L, hydrogen ion concentration 5.60 mol / L, fluoride ion concentration 2.02 mol / L) from Example 1 was used, and 1.2 times the theoretical amount of hydrogen peroxide was added for oxidation / complexation, with a total added amount of 16.74 g / L; then, the niobic solution was acidified using a combination of sulfuric acid and hydrofluoric acid solutions, controlling the sulfuric acid concentration at 4.62 mol / L and the hydrofluoric acid concentration at 4.52 mol / L. Next, a mixed extraction system of N,N-dimethylheptylacetamide and 2-octanol (60% by volume of the extractant component) was selected and mixed with the acidified niobium extraction solution at an organic phase / aqueous phase volume ratio of 1.05:1.0 in a separatory funnel for five-stage countercurrent extraction. The shaking time was controlled at 10 min to obtain a clean niobium residue solution after removing tantalum and antimony. The antimony removal rate was 93%, the tantalum removal rate was 98.5%, and the niobium loss rate was about 7.1%. Then, ammonia water was slowly added to the clean niobium solution while stirring continuously. The pH value at the precipitation endpoint was controlled at about 8.5. After a large amount of white solid precipitated, the solution was filtered and vacuum dried. The completely dried niobium solid was then calcined at 850℃ for 6 hours to obtain a high-purity niobium oxide product. The antimony content in the niobium oxide was tested to be less than 2.5 ppm and the tantalum content was less than 2 ppm, meeting the requirements of 4N grade high-purity niobium oxide product.

[0030] Example 4

[0031] A niobic acid solution containing 1.2 g / L Ta and 20 mg / L Sb (28 g / L Nb) was prepared. The sulfuric acid concentration was controlled at approximately 6.0 mol / L and the fluoride ion concentration at approximately 5.5 mol / L. 1.2 times the theoretical volume of hydrogen peroxide was added for oxidation / complexation, with a total added volume of 6.87 g / L. Then, a mixed extraction system of tributyl phosphate and 2-octanol (80% by volume of the extractant) was used. The acidified niobium extraction solution was mixed with this system in a separatory funnel at a 1:1 organic / aqueous phase volume ratio and subjected to a 7-stage countercurrent extraction. The shaking time was controlled at 10 min to obtain clean niobium residue after the removal of tantalum and antimony. The antimony removal rate was 91%, the tantalum removal rate was 98.5%, and the niobium loss rate was about 6.8%. Then, ammonia water was slowly added to the clean niobium solution while stirring continuously. The pH value at the precipitation endpoint was controlled at about 9.0. After a large amount of white solid precipitated, it was filtered and vacuum dried. The completely dried niobium solid was then oxidized and calcined at 850℃ for 5 hours to obtain high-purity niobium oxide. The antimony content and tantalum content in the niobium oxide were tested to be less than 3 ppm, which also met the requirements of 4N grade high-purity niobium oxide products.

[0032] Example 5

[0033] A niobic acid solution containing 1.2 g / L Ta and 20 mg / L Sb (Nb 28 g / L) was prepared. The sulfuric acid concentration was controlled at approximately 6.0 mol / L and the fluoride ion concentration at approximately 5.5 mol / L. Hydrogen peroxide (1.2 times the theoretical volume) was added for oxidation / complexation, with a total addition of 6.87 g / L. Then, a tributyl phosphate (TBP) extraction system (80% by volume) was used, and the acidified niobium extraction solution was mixed with the solution at an organic phase / aqueous phase volume ratio of 1.1:1 in a separatory funnel for a 7-stage countercurrent extraction. The shaking time was controlled at 10 min to obtain a clean raffinate after removing tantalum and antimony. The niobium solution had an antimony removal rate of 91.7%, a tantalum removal rate of 98.7%, and a niobium loss rate of approximately 8.0%. Ammonia was then slowly added to the clean niobium solution with continuous stirring, controlling the pH at the precipitation endpoint to approximately 9.0. After a large amount of white solid precipitated, the solution was filtered and vacuum dried. The completely dried niobium solid was then oxidized and calcined at 850℃ for 5 hours to obtain high-purity niobium oxide. Testing showed that the antimony content and tantalum content in the niobium oxide were less than 3 ppm, meeting the requirements for 4N-grade high-purity niobium oxide.

[0034] Comparative Example 1

[0035] The only difference from Example 3 is that the niobium solution was used for acid adjustment directly without adding hydrogen peroxide. All other operations and conditions were the same as in Example 3.

[0036] The final measured antimony removal rate in the solution after extraction equilibrium was 83%, tantalum removal rate was 92%, but niobium loss rate reached 18.8%.

[0037] Comparative Example 2

[0038] The only difference from Example 1 is that the niobium solution was used for acid adjustment directly without adding hydrogen peroxide. All other operations and conditions were the same as in Example 1.

[0039] The final measured antimony removal rate in the solution after extraction equilibrium was 80%, tantalum removal rate was 92.1%, but niobium loss rate was as high as 24.9%.

Claims

1. A method for deep removal of antimony and tantalum from a niobium-containing solution, characterized in that: A niobium solution containing antimony, tantalum, and fluorine is first oxidized and complexed with an inorganic peroxide, followed by acid adjustment and extraction to remove impurities, resulting in a niobium-containing purified solution. The oxidation and complexation conditions are: temperature of 5~40℃ and oxidation and complexation time of 0.5~2h. The amount of inorganic peroxide added to the niobium solution is 10~16g / L.

2. The method for deep deantimony and detantalation of niobium-containing solution according to claim 1, characterized in that: The niobium solution contains Nb at a concentration of 60-70 g / L, Sb at a concentration of 0.01-0.12 g / L, Ta at a concentration of 0.2-0.4 g / L, hydrogen ion at a concentration of 1-6 mol / L, and fluoride ion at a concentration of 1-4 mol / L.

3. The method for deep deantimony and detantalation of niobium-containing solution according to claim 1, characterized in that: The inorganic peroxide includes at least one of hydrogen peroxide, sodium peroxide, and barium peroxide.

4. The method for deep removal of antimony and tantalum from a niobium-containing solution according to claim 1, characterized in that: The acid-adjusting reagents used in the acid-adjusting process include at least one of hydrofluoric acid, sulfuric acid, nitric acid, and hydrochloric acid. During the acid adjustment process, the acid concentration of the solution system is adjusted to 6~10 mol / L.

5. The method for deep removal of antimony and tantalum from a niobium-containing solution according to claim 1, characterized in that: The extraction process uses at least one of the following extractants: ketone extractants, alcohol extractants, amide extractants, phosphine oxide extractants, and phosphonate extractants. The ketone extractant includes at least one of methyl isobutyl ketone and methyl isopropyl ketone; The alcohol extractant includes at least one of 2-octanol, isooctanol, and pentanol; The amide extractant includes at least one of N,N-dimethylheptylacetamide, N,N-di-n-mixed acetamide, and N-phenyl-N-octylacetamide; The phosphine oxide extractant includes at least one of tributylphosphine oxide, trioctylphosphine oxide, and trialkylphosphine oxide; The phosphonate extractant includes at least one of tributyl phosphate, trioctyl phosphate, and dibutyl butylphosphonate.

6. A method for deep removal of antimony and tantalum from a niobium-containing solution according to claim 1 or 5, characterized in that: The extraction process employs a multi-stage extraction method, with 1 to 7 extraction stages. The volume percentage of the extractant in the organic phase is not less than 20%, the O / W phase volume ratio is 1.3 to 0.95:1, the extraction temperature is 0 to 40°C, and the extraction time is 5 to 10 minutes.

7. The method for deep deantimony and detantalation of niobium-containing solutions according to claim 6, characterized by that: The extractable organic phase contains a diluent; the diluent includes at least one of sulfonated kerosene, 260# solvent oil, paraffin oil, and n-octane; the volume percentage of the diluent in the extractable organic phase is less than 20%.

Images