Short-process preparation method of ultra-pure fluorine tantalic acid solution

Abstract

The invention provides a short-process preparation method of an ultra-high-purity fluorine tantalic acid solution, which utilizes a hydrofluoric acid-sulfuric acid-MIBK combined system, adopts a tantalum-containing solution as a raw material, and realizes efficient preparation of the high-purity fluorine tantalic acid solution through the process steps of acid adjustment, extraction, acid pickling and tantalum removal. According to the preparation method, the production efficiency is improved, the production cost is reduced, the product quality and purity are remarkably improved, and reliable technical support and application prospects are provided for industrial production of the high-purity fluorine tantalic acid solution.

Description

Technical Field

[0001] The invention relates to the technical field of chemical engineering, and in particular to a short-process preparation method for an ultra-high purity fluorotantalate solution. Background Art

[0002] Fluorotantalate solution is an important tantalum compound, widely used in the fields of chemistry, electronics, aerospace, etc. Its purity and stability have a crucial impact on the quality and performance of subsequent products. However, there are many shortcomings in the preparation method of high-purity fluorotantalate solution in the prior art. The traditional process mainly relies on tantalum metal waste as raw material. After dissolving tantalum metal with hydrofluoric acid, high-purity fluorotantalate solution is prepared through multiple steps such as acid adjustment, extraction, pickling, reverse niobium extraction of tantalum, and reverse tantalum. This method has problems such as lengthy process, long production cycle, single source of raw materials, high production cost, unstable purity, etc., which limits its wide application and promotion in actual production.

[0003] The existing process for preparing high-purity fluorotantalate solution generally includes the following steps: first, tantalum metal waste is added to hydrofluoric acid for leaching to obtain a tantalum-containing leachate; then the acid is adjusted to obtain a tantalum stock solution, and an organic solvent (such as MIBK) is used to extract tantalum into the organic phase to form a tantalum-loaded organic solution. Then, after acid washing, reverse niobium extraction of tantalum, reverse tantalum and other steps, repeated extraction is performed to finally prepare a high-purity fluorotantalate solution. However, the presence of reverse niobium extraction of tantalum and reverse tantalum steps in the traditional method not only increases the number of equipment and energy consumption, but also leads to a complex process flow and high production costs. In addition, when tantalum metal reacts with inorganic acid, hydrogen is easily generated, which poses certain safety hazards. These factors have put forward higher requirements for actual production. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a short-process method for preparing a high-purity fluorotantalate solution based on a hydrofluoric acid-sulfuric acid-MIBK (including but not limited to MIBK) system.

[0005] The preparation method of the present invention comprises the following steps:

[0006] A short-process preparation method for an ultra-high purity fluorotantalate solution comprises the following steps:

[0007] (1) Acidity adjustment: using a tantalum-containing solution as a raw material, adjusting the molar concentrations of hydrofluoric acid and sulfuric acid in the initial tantalum-containing solution, and adjusting the molar concentration of hydrofluoric acid to 2.0 mol / L and the molar concentration of sulfuric acid to 0.5 mol / L by adding concentrated hydrofluoric acid and concentrated sulfuric acid, to obtain a prepared tantalum stock solution;

[0008] (2) Extraction and separation: The prepared tantalum stock solution is subjected to multi-stage extraction with the MIBK extractant to form a tantalum-loaded organic phase, which is then washed and removed with an acid wash agent to obtain an acid-washed tantalum-loaded organic phase, which is then subjected to multi-stage stripping with a high-purity stripping agent to finally obtain a high-purity fluorotantalate solution;

[0009] (3) Testing process: The obtained high-purity fluorotantalate solution is added to ammonia water to precipitate tantalum into tantalum hydroxide powder, and the purity and impurity tests are performed according to the standards.

[0010] The initial total oxide concentration of the tantalum-containing solution is 70-90 g / L, and the initial total oxide is calculated as (Ta+Nb)2O5.

[0011] The extraction and separation step includes two extraction tanks, in which the prepared tantalum stock solution and MIBK are subjected to 6-stage extraction, and in the second extraction tank, the tantalum-containing loaded organic phase after acid washing and the anti-tantalum agent are subjected to 20-stage back extraction.

[0012] In the first extraction tank, the flow ratio of MIBK to tantalum stock solution is 1:1, and the flow ratio of pickling agent to tantalum stock solution is 0.6.

[0013] In the second extraction tank, the flow ratio of the anti-tantalum agent to the tantalum-containing loaded organic phase is 1:1.2.

[0014] The purity of the MIBK is not less than 99.5 wt %.

[0015] The pickling agent is a 1.8 mol / L sulfuric acid solution.

[0016] The anti-tantalum agent is four-times exchange water, wherein Si≤0.1ppm, and Fe, Al, K, Na, Ca, and Mg are all≤0.01ppm.

[0017] The total oxide concentration of the high-purity fluorotantalate solution is 75.6-80.6 g / L, where the total oxide is calculated as Ta2O5.

[0018] The detection process adds ammonia water to the high-purity fluorotantalate solution to precipitate the tantalum into tantalum hydroxide powder, and performs purity and impurity detection and analysis in accordance with the JY-T0567-2020 standard.

[0019] As described above, the present invention provides a new method for preparing a high-purity fluorotantalate solution, which is based on a combined system of hydrofluoric acid-sulfuric acid-MIBK (including but not limited to MIBK), and uses a tantalum-containing solution as a raw material, replacing the traditional process of using tantalum metal waste as a raw material. This method can effectively simplify the process flow and reduce production costs by removing the reverse niobium tantalum extraction stage in the traditional process and using a combined process of acid adjustment, extraction, pickling and reverse tantalum. At the same time, the present invention not only reduces the use of extractants and stripping agents, reduces the investment and energy consumption of equipment in the production process, but also avoids the generation of hydrogen during the leaching process, significantly improving the safety and controllability of the production process.

[0020] The present invention provides a method for preparing a high-purity fluorotantalate solution in a short process, which has the following beneficial effects compared with the traditional preparation process:

[0021] 1. Shorten the process flow and improve production efficiency: The present invention uses tantalum-containing solution as raw material, simplifies the complicated steps of inverse niobium extraction of tantalum and inverse tantalum in the traditional process, and makes the production process more concise and efficient. Compared with the 5-6 day production cycle of the traditional preparation method, the process of the present invention can shorten the cycle to 1 day, greatly improving production efficiency and meeting the demand for fast and efficient production in industrial production.

[0022] 2. Reduce production costs: The present invention reduces the use of extractants and stripping agents by eliminating multiple extraction steps in the traditional process, and reduces the consumption of chemicals in the production process. At the same time, the simplified process reduces the number of equipment, reduces equipment investment and energy consumption, and significantly reduces the overall production cost.

[0023] 3. Expand the scope of raw material application: Traditional preparation methods usually rely on a single tantalum metal waste as raw material, while the present invention can be widely applied to a variety of tantalum-niobium-containing materials, including tantalum-niobium ore, tantalum-niobium waste, discarded tantalum-niobium electronic components, etc. This diversified raw material selection not only broadens the source of raw materials, but also alleviates the dependence of production on a single raw material, and improves the applicability and flexibility of the process.

[0024] 4. Improve production safety: In the traditional process, tantalum metal easily generates hydrogen when reacting with inorganic acid, which poses certain safety hazards. The present invention effectively avoids the generation of hydrogen by using tantalum-containing solution as raw material, reduces the safety risk in the leaching process, and improves the controllability of production.

[0025] 5. High product purity and stable quality: The present invention adopts advanced separation and purification technology, which can effectively enrich tantalum elements, ensure the high purity of fluorotantalate solution, and meet the stringent requirements of different industries for the quality of fluorotantalate solution. At the same time, the process flow of the present invention is stable, which can realize continuous production and ensure the consistency and stability of product quality.

[0026] 6. Improve enterprise competitiveness: The simplified process, shortened production cycle and reduced costs of the present invention not only improve production efficiency, but also enhance the economic benefits and market competitiveness of production, and can better meet the market's increasingly stringent quality requirements for high-end tantalum products, thus bringing greater competitive advantages to enterprises.

[0027] In summary, the present invention not only effectively solves the key problems in the prior art through innovations in process flow, raw material selection and safety, but also significantly improves the production efficiency of high-purity fluorotantalate solution and reduces costs, providing important technical support for the production of high-end tantalum products. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a flow chart of acidity adjustment in the present invention.

[0029] Figure 2 It is the extraction separation flow chart of the present invention. DETAILED DESCRIPTION

[0030] The present invention is described in detail below through specific examples. Those skilled in the art will appreciate that these examples are only used to illustrate the present invention and do not limit the scope of the present invention in any way.

[0031] The experimental methods in the following examples are conventional methods unless otherwise specified. The various solutions used in the following examples are commercially available products unless otherwise specified. Among them, concentrated hydrofluoric acid is chemically pure with a molar concentration of 36 mol / L; concentrated sulfuric acid is chemically pure with a molar concentration of 18 mol / L.

[0032] Example 1: Preparation of high purity fluorotantalate solution

[0033] 1. Acidity adjustment, the process is as follows Figure 1 Shown

[0034] Tantalum solution volume: 600L

[0035] Total oxide concentration of initial tantalum-containing solution (calculated as (Ta+Nb)2O5): 90 g / L

[0036] Hydrofluoric acid molar concentration: 0.86 mol / L

[0037] Molar concentration of sulfuric acid: 0mol / L

[0038] Mixed acid solution molar concentration test: The total molar concentration of free acid is titrated with sodium hydroxide (NaOH) standard solution using a mixed solution of methyl orange and methylene blue as an indicator. According to the equivalent law N1V1=N2V2, the total molar concentration of free hydrofluoric acid (HF) and sulfuric acid (H2SO4) can be calculated; after evaporating the hydrofluoric acid on a water bath, titrate with methyl orange as an indicator to calculate the molar concentration of free sulfuric acid. The difference between the total free molar concentration and the free sulfuric acid molar concentration is the molar concentration of hydrofluoric acid;

[0039] Add 21.17L of concentrated hydrofluoric acid and 17.75L of concentrated sulfuric acid

[0040] The molar concentration of hydrofluoric acid after preparation is 2.0 mol / L, and the molar concentration of sulfuric acid is 0.5 mol / L

[0041] The final total volume of tantalum stock solution is 638.11L, and the total oxide concentration is 84.6g / L

[0042] 2. Extraction and separation, the process is as follows Figure 2 Shown

[0043] Extraction reagents:

[0044] Tantalum stock solution: total oxide concentration is 84.6g / L

[0045] Extractant: MIBK (content ≥ 99.5wt%)

[0046] Pickling agent: 1.8 mol / L sulfuric acid solution

[0047] Tantalum anti-agent: Four times water exchange, extremely low impurity content (Si≤0.1ppm, Fe, Al, K, Na, Ca, Mg are all ≤0.01ppm)

[0048] Operation process:

[0049] The first extraction tank: the tantalum stock solution is subjected to 6-stage extraction with MIBK to obtain the tantalum-loaded organic phase I; then the tantalum-loaded organic phase II is obtained by 14-stage acid washing with an acid washing agent.

[0050] Second stage extraction tank: Tantalum-loaded organic phase II is subjected to 20-stage back extraction with the anti-tantalum agent to obtain ultra-high purity fluorotantalate solution

[0051] Flow rate ratio of each reagent into the tank:

[0052] The first stage: MIBK: Tantalum stock solution: Pickling agent = 1:1:0.6

[0053] The second stage: Tantalum-containing organic phase II: anti-tantalum agent = 1: 1.2

[0054] The total oxide concentration of the final fluorotantalate solution was 79.54 g / L

[0055] 3. Inspection process

[0056] The tantalum in the high-purity fluorotantalate solution is precipitated by analytical pure ammonia water, and the obtained high-purity tantalum hydroxide powder is tested and analyzed according to the JY-T0567-2020 standard.

[0057] Example 2: Preparation of high purity fluorotantalate solution

[0058] 1. Acidity adjustment

[0059] Tantalum solution volume: 800L

[0060] Total oxide concentration of initial tantalum-containing solution (calculated as (Ta+Nb)2O5): 80 g / L

[0061] Hydrofluoric acid molar concentration: 0.72 mol / L

[0062] Molar concentration of sulfuric acid: 0mol / L

[0063] Add 33.52L of chemically pure concentrated hydrofluoric acid and 23.76L of chemically pure concentrated sulfuric acid

[0064] The molar concentration of hydrofluoric acid after preparation is 2.0 mol / L, and the molar concentration of sulfuric acid is 0.5 mol / L

[0065] The final total volume of tantalum stock solution is 854.8L, and the total oxide concentration is 74.82g / L

[0066] 2. Extraction and separation

[0067] Extraction reagent: Same as Example 1

[0068] Operation process:

[0069] The first extraction tank: the tantalum stock solution is subjected to 6-stage extraction with MIBK to obtain the tantalum-loaded organic phase I; then the tantalum-loaded organic phase II is obtained by 14-stage acid washing with an acid washing agent.

[0070] Second stage extraction tank: Tantalum-loaded organic phase II is subjected to 20-stage back extraction with the anti-tantalum agent to obtain ultra-high purity fluorotantalate solution

[0071] Flow rate ratio of each reagent into the tank:

[0072] The first stage: MIBK: Tantalum stock solution: Pickling agent = 1:1:0.6

[0073] The second stage: Tantalum-containing organic phase II: anti-tantalum agent = 1: 1.2

[0074] The total oxide concentration of the final fluorotantalate solution was 75.6 g / L

[0075] 3. Inspection process

[0076] The tantalum in the high-purity fluorotantalate solution is precipitated by analytical pure ammonia water, and the obtained high-purity tantalum hydroxide powder is tested and analyzed according to the JY-T0567-2020 standard.

[0077] Example 3: Preparation of high purity fluorotantalate solution

[0078] 1. Acidity adjustment

[0079] Tantalum solution volume: 800L

[0080] Total oxide concentration of initial tantalum-containing solution (calculated as (Ta+Nb)2O5): 70 g / L

[0081] Hydrofluoric acid molar concentration: 0.65 mol / L

[0082] Molar concentration of sulfuric acid: 0mol / L

[0083] Add 33.16L of chemically pure concentrated hydrofluoric acid and 23.8L of chemically pure concentrated sulfuric acid

[0084] The molar concentration of hydrofluoric acid after preparation is 2.0 mol / L, and the molar concentration of sulfuric acid is 0.5 mol / L

[0085] The final total volume of tantalum stock solution is 856.45L, and the total oxide concentration is 65.25g / L

[0086] 2. Extraction and separation

[0087] Extraction reagent: Same as Example 1

[0088] Operation process:

[0089] The first extraction tank: the tantalum stock solution is subjected to 6-stage extraction with MIBK to obtain the tantalum-loaded organic phase I; then the tantalum-loaded organic phase II is obtained by 14-stage acid washing with an acid washing agent.

[0090] Second stage extraction tank: Tantalum-loaded organic phase II is subjected to 20-stage back extraction with the anti-tantalum agent to obtain ultra-high purity fluorotantalate solution

[0091] Flow rate ratio of each reagent into the tank:

[0092] The first stage: MIBK: Tantalum stock solution: Pickling agent = 1:1:0.6

[0093] The second stage: Tantalum-containing organic phase II: anti-tantalum agent = 1: 0.8

[0094] The total oxide concentration of the final fluorotantalate solution is 80.6 g / L

[0095] Testing process

[0096] By adding analytical grade ammonia to the high-purity fluorotantalate solution, tantalum is precipitated in the solution as high-purity tantalum hydroxide powder. The obtained high-purity tantalum hydroxide powder is sampled and analyzed and tested according to the JY-T0567-2020 standard to obtain the main components and impurity content, ensuring that the purity of the high-purity fluorotantalate solution meets the standard requirements.

[0097] Table 1 Quality test results of high purity fluorotantalate prepared in Examples 1-3

[0098]

[0099]

[0100] Table 1 lists the main components and impurity element contents of the high-purity fluorotantalate solutions prepared in Examples 1 to 3 of the present invention:

[0101] Main component (Ta2O5):

[0102] The mass percentages of the main components in Examples 1, 2 and 3 are 99.9964%, 99.9970% and 99.9959% respectively.

[0103] This indicates that the high-purity fluorotantalate solution prepared by the present invention has extremely high purity and can meet the high-purity requirements of high-end tantalum products for fluorotantalate solution.

[0104] Impurity element content:

[0105] The impurity elements listed in the table include Nb (niobium), Al (aluminum), Bi (bismuth), Ca (calcium), Cr (chromium), Cu (copper), Fe (iron), Mg (magnesium), Mn (manganese), Mo (molybdenum), Ni (nickel), Pb (lead), Sb (antimony), Si (silicon), Sn (tin), Ti (titanium), Zr (zirconium), etc.

[0106] The content of each impurity element is within an extremely low range (mostly <0.0005%), which indicates that the preparation method of the present invention can effectively remove these impurities and ensure the purity of the high-purity fluorotantalate solution.

[0107] Differences in impurity element content:

[0108] There are slight differences in the contents of some impurity elements in various examples. For example, the Ca content (0.0008%) of Example 2 is lower than that of Example 1 (0.0012%), while the Bi content (0.00005%) of Example 3 is higher than that of Example 1 and Example 2 (<0.00001%). These differences may be caused by the effects of different concentrations and volumes of the initial tantalum-containing solutions on the separation process.

[0109] Overall purity level and manufacturing consistency:

[0110] Table 1 shows that the main component content and impurity element content of the high-purity fluorotantalate solution in Examples 1 to 3 vary in a small range, indicating that the preparation method can stably prepare high-purity fluorotantalate solution under different conditions, with good production consistency and repeatability.

[0111] Examples 1 to 3 of the present invention use tantalum-containing solutions of different initial concentrations and volumes, and prepare high-purity fluorotantalate solutions through acid adjustment, extraction separation and detection processes. The final high-purity fluorotantalate solutions have total oxide concentrations of 79.54 g / L, 75.6 g / L and 80.6 g / L, respectively. This preparation method not only simplifies the traditional process flow, improves production efficiency, but also reduces production costs. After the detection process of the high-purity fluorotantalate solution, the effectiveness of the preparation method of the present invention and the purity of the product are verified, meeting the quality requirements of high-end tantalum products.

[0112] Through the above examples, the present invention demonstrates the versatility and stability of efficiently preparing high-purity fluorotantalate solution under different tantalum-containing solution raw materials and process parameters, providing a reliable technical guarantee for industrial production.

Claims

1. A short-process preparation method for ultra-high purity fluorotantalate solution, characterized in that: The following steps are involved: (1) Acidity adjustment: using a tantalum-containing solution as a raw material, adjusting the molar concentrations of hydrofluoric acid and sulfuric acid in the initial tantalum-containing solution, and adjusting the molar concentration of hydrofluoric acid to 2.0 mol / L and the molar concentration of sulfuric acid to 0.5 mol / L by adding concentrated hydrofluoric acid and concentrated sulfuric acid, to obtain a prepared tantalum stock solution; (2) Extraction and separation: The prepared tantalum stock solution is subjected to multi-stage extraction with the MIBK extractant to form a tantalum-loaded organic phase, which is then washed and removed with an acid wash agent to obtain an acid-washed tantalum-loaded organic phase, which is then subjected to multi-stage stripping with a high-purity stripping agent to finally obtain a high-purity fluorotantalate solution; (3) Testing process: The obtained high-purity fluorotantalate solution is added to ammonia water to precipitate tantalum into tantalum hydroxide powder, and the purity and impurity tests are performed according to the standards.

2. The method for preparing a high-purity fluorotantalate solution according to claim 1, characterized in that: The initial total oxide concentration of the tantalum-containing solution is 70-90 g / L, and the initial total oxide is calculated as (Ta+Nb)2O5.

3. The method for preparing a high-purity fluorotantalate solution according to claim 1 or 2, characterized in that: The extraction and separation step includes two extraction tanks, in which the prepared tantalum stock solution and MIBK are subjected to 6-stage extraction, and in the second extraction tank, the tantalum-containing loaded organic phase after acid washing and the anti-tantalum agent are subjected to 20-stage back extraction.

4. The method for preparing a high-purity fluorotantalate solution according to claim 3, characterized in that: In the first extraction tank, the flow ratio of MIBK to tantalum stock solution is 1:1, and the flow ratio of pickling agent to tantalum stock solution is 0.6:

1.

5. The method for preparing a high-purity fluorotantalate solution according to claim 3 or 4, characterized in that: In the second extraction tank, the flow ratio of the anti-tantalum agent to the tantalum-containing loaded organic phase is 1:1.

2.

6. The method for preparing a high-purity fluorotantalate solution according to any one of claims 1 to 5, characterized in that: The purity of the MIBK is not less than 99.5 wt %.

7. The method for preparing a high-purity fluorotantalate solution according to any one of claims 1 to 6, characterized in that: The pickling agent is a 1.8 mol / L sulfuric acid solution.

8. The method for preparing a high-purity fluorotantalate solution according to any one of claims 1 to 7, characterized in that: The anti-tantalum agent is four-times exchange water, wherein Si≤0.1ppm, and Fe, Al, K, Na, Ca, and Mg are all≤0.01ppm.

9. The method for preparing a high-purity fluorotantalate solution according to any one of claims 1 to 8, characterized in that: The total oxide concentration of the high-purity fluorotantalate solution is 75.6-80.6 g / L, where the total oxide is calculated as Ta2O5.

10. The method for preparing a high-purity fluorotantalate solution according to any one of claims 1 to 9, characterized in that: The detection process adds ammonia water to the high-purity fluorotantalate solution to precipitate the tantalum into tantalum hydroxide powder, and performs purity and impurity detection and analysis in accordance with the JY-T0567-2020 standard.

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