Method for preparing low-antimony high-purity fluorine tantalic acid solution by adopting tantalum-containing and antimony-containing solution

Abstract

The invention relates to the technical field of chemical production, in particular to a method for preparing a low-antimony high-purity fluorine tantalic acid solution by adopting a tantalum-containing and antimony-containing solution, which comprises the following steps: S101, adding inorganic acid into the antimony-containing and tantalum-containing solution for modulation; s102, extracting the prepared antimony-containing and tantalum-containing solution by using an organic solvent to obtain an organic phase I; s103, removing impurities in the organic phase I by using a pickling agent to obtain an organic phase II; s104, washing the organic phase II by using an anti-niobium agent to obtain an organic phase III and a fluorine niobic acid water phase; s105, carrying out tantalum extraction organic extraction operation on the fluorine niobic acid water phase to obtain an organic phase IV; s106, the organic phase III and the organic phase IV are converged in an extraction tank, and then a low-antimony high-purity fluorine tantalic acid solution is obtained through reverse extraction of an anti-tantalum agent; therefore, by adjusting the acidity gradient and the phase ratio of the organic phase to the reagent in each step, the distribution ratio of the impurity antimony in the organic phase and the water phase is changed, so that the content of the impurity antimony is reduced in the extraction process, and the purity of the high-purity fluotantalic acid solution is improved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical production, and in particular to a method for preparing a low-antimony high-purity fluorotantalate solution by using a tantalum- and antimony-containing solution. Background Art

[0002] With the increasingly stringent demand for high-quality tantalum products in high-tech fields such as electronic technology, microelectronics technology and communication technology, high-purity fluorotantalate solution, as the raw material for producing high-quality tantalum products, has an important influence on the performance and quality of tantalum products. High-purity fluorotantalate solution can reduce impurities, make the tantalum powder purer and more uniform in particle size, thereby increasing the capacitance of the manufactured tantalum capacitor and reducing the loss of tantalum capacitors.

[0003] Common impurities in fluorotantalate solution include antimony, iron and chromium. Antimony, as a hazardous impurity, will cause subsequent tantalum products to have problems such as increased brittleness, reduced corrosion resistance and changes in physical properties. Therefore, the antimony content is particularly important to the quality of high-purity fluorotantalate solution. However, when producing high-purity fluorotantalate solution from complex mineral raw materials such as tantalite-niobium ore with a high antimony content, it is difficult to control the impurity antimony. The antimony content in the high-purity fluorotantalate solution prepared in this way is mostly above 10ppm. At the same time, the chemical properties of tantalum and antimony are similar under the extraction system, making it difficult to separate antimony from the high-purity fluorotantalate solution, resulting in a decrease in the purity of the fluorotantalate solution. Summary of the invention

[0004] In view of this, it is necessary to provide a method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution, which can reduce the content of antimony impurities in the prepared fluorotantalate solution, thereby improving the purity of the fluorotantalate solution.

[0005] The present invention provides a method for preparing a low-antimony high-purity fluorotantalate solution by using a tantalum-containing and antimony-containing solution, comprising the following steps: S101, adding an inorganic acid to the antimony-containing tantalum-containing solution in an extraction tank for modulation to adjust the acidity of the antimony-containing tantalum-containing solution so that the acidity gradient distribution in the extraction tank is the same as the predetermined acidity gradient distribution; S102, extracting the modulated antimony-containing and tantalum-containing solution with an organic solvent to allow metal ions to enter the organic phase to obtain an organic phase I, wherein the ratio of the organic solvent to the antimony-containing and tantalum-containing solution is a first predetermined ratio; S103, using a pickling agent to remove impurities in the organic phase I to obtain an organic phase II, wherein the ratio of the organic phase I to the pickling agent is a second predetermined ratio; S104, washing the organic phase II with a reverse niobium agent to obtain an organic phase III and a fluoroniobate aqueous phase, wherein the ratio of the organic phase II to the reverse niobium agent is a third predetermined ratio; S105, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum to obtain an organic phase IV; S106, combining organic phase III and organic phase IV in an extraction tank to obtain organic phase V, and then stripping organic phase V with a reverse tantalum agent to obtain a low-antimony high-purity fluorotantalate solution, wherein the ratio of organic phase V to the reverse tantalum agent is a fourth predetermined ratio.

[0006] Preferably, in the antimony-containing tantalum-containing solution in step S101, the total amount of tantalum oxide and niobium oxide is 50-120 g / L, and the antimony content is 7×10 -3 ~12×10 -3 g / L.

[0007] Preferably, the inorganic acid in step S101 is at least one of hydrofluoric acid and sulfuric acid.

[0008] Preferably, the organic solvent used in step S102 is methyl isobutyl ketone or 2-octanol.

[0009] Preferably, the pickling agent used in step S103 is a 1.0-2.5 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

[0010] Preferably, the anti-niobium agent used in step S104 is a 0.4-0.9 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

[0011] Preferably, the anti-tantalum agent used in step S106 is secondary pure water.

[0012] The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution is provided with the following steps: S101, adding an inorganic acid to the antimony-containing and tantalum-containing solution in an extraction tank for modulation to adjust the acidity of the antimony-containing and tantalum-containing solution so that the acidity gradient distribution in the extraction tank is the same as the predetermined acidity gradient distribution; S102, extracting the modulated antimony-containing and tantalum-containing solution with an organic solvent so that metal ions enter the organic phase to obtain an organic phase I, wherein the ratio of the organic solvent to the antimony-containing and tantalum-containing solution is a first predetermined ratio; S103, removing impurities in the organic phase I with an acid wash agent to obtain Organic phase II, wherein the ratio of organic phase I to the pickling agent is the second predetermined ratio; S104, washing organic phase II with an anti-niobium agent to obtain organic phase III and a fluoroniobate aqueous phase, wherein the ratio of organic phase II to the anti-niobium agent is the third predetermined ratio; S105, performing a tantalum organic extraction operation on the fluoroniobate aqueous phase to obtain an organic phase IV; S106, combining organic phase III and organic phase IV in an extraction tank to obtain an organic phase V, and then back-extracting organic phase V with an anti-tantalum agent to obtain a low-antimony high-purity fluorotantalate solution, wherein the ratio of organic phase V to the anti-tantalum agent is the fourth predetermined ratio. In this way, by adjusting the acidity gradient of the antimony-containing and tantalum-containing solution and the ratio of the organic phase to the corresponding reagent in each step, the distribution ratio of the impurity antimony is changed, so that the impurity antimony enters the aqueous phase from each organic phase, so as to reduce the content of the impurity antimony in the process of extracting and separating each organic phase and the aqueous phase, thereby reducing the content of the impurity antimony in the prepared high-purity fluorotantalate solution and improving the purity of the high-purity fluorotantalate solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the method of the present application for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution. DETAILED DESCRIPTION

[0014] The technical solutions and technical effects of the embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings of the present invention.

[0015] The present invention provides a method for preparing a low-antimony high-purity fluorotantalate solution by using a tantalum-containing and antimony-containing solution, comprising the following steps: S101, adding an inorganic acid to the antimony-containing tantalum-containing solution in an extraction tank for modulation to adjust the acidity of the antimony-containing tantalum-containing solution so that the acidity gradient distribution in the extraction tank is the same as the predetermined acidity gradient distribution; S102, extracting the modulated antimony-containing and tantalum-containing solution with an organic solvent to allow metal ions to enter the organic phase to obtain an organic phase I, wherein the ratio of the organic solvent to the antimony-containing and tantalum-containing solution is a first predetermined ratio; S103, using a pickling agent to remove impurities in the organic phase I to obtain an organic phase II, wherein the ratio of the organic phase I to the pickling agent is a second predetermined ratio; S104, washing the organic phase II with a reverse niobium agent to obtain an organic phase III and a fluoroniobate aqueous phase, wherein the ratio of the organic phase II to the reverse niobium agent is a third predetermined ratio; S105, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum to obtain an organic phase IV; S106, combining organic phase III and organic phase IV in an extraction tank to obtain organic phase V, and then stripping organic phase V with a reverse tantalum agent to obtain a low-antimony high-purity fluorotantalate solution, wherein the ratio of organic phase V to the reverse tantalum agent is a fourth predetermined ratio.

[0016] In this way, by adjusting the acidity gradient of the antimony-containing and tantalum-containing solutions and the ratio of the organic phase to the corresponding reagent in each step, the distribution ratio of the antimony impurity is changed, so that the antimony impurity enters the aqueous phase from each organic phase, so as to reduce the content of the antimony impurity in the process of extracting and separating the organic phase and the aqueous phase, thereby reducing the content of the antimony impurity in the prepared high-purity fluorotantalate solution and improving the purity of the high-purity fluorotantalate solution.

[0017] Furthermore, in the antimony-containing tantalum-containing solution in step S101, the total amount of tantalum oxide and niobium oxide is 50-120 g / L, and the antimony content is 7×10 -3 ~12×10 -3 g / L.

[0018] Furthermore, the inorganic acid in step S101 is at least one of hydrofluoric acid and sulfuric acid.

[0019] Furthermore, the organic solvent used in step S102 is methyl isobutyl ketone or 2-octanol.

[0020] Furthermore, the pickling agent used in step S103 is a 1.0-2.5 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

[0021] Furthermore, the anti-niobium agent used in step S104 is a 0.4-0.9 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

[0022] Furthermore, the anti-tantalum agent used in step S106 is secondary pure water.

[0023] The following examples are the process of preparing low antimony high purity fluorotantalate solution using reagents of different concentrations. Embodiment 1:

[0024] S201, adjusting the high antimony tantalum-containing solution (the total amount of tantalum oxide and niobium oxide is 90 g / L, and the antimony content is 9×10-3 g / L) with hydrofluoric acid and sulfuric acid to a hydrofluoric acid concentration of 1.8 mol / L and a sulfuric acid concentration of 0.6 mol / L to obtain a tantalum-containing stock solution; S202, using MIBK as an extractant to perform countercurrent extraction with the tantalum-containing stock solution in an 8-stage extraction tank, with the volume ratio of the organic phase to the aqueous phase being 1:1.2, to obtain a tantalum-containing organic phase I; S203, 1.5 mol / L pickling agent is prepared with 98% analytical pure sulfuric acid, the volume ratio of organic phase I to pickling agent is 1:0.7, and the organic phase II is obtained by countercurrent washing in an 8-stage extraction tank; S204, using 0.5 mol / L reverse niobium agent prepared with 98% analytical pure sulfuric acid, the organic phase II and the reverse niobium agent are subjected to countercurrent extraction in a 10-stage extraction tank, the volume ratio of the organic phase II to the reverse niobium agent is 1:0.65, and an organic phase III and a fluoroniobate aqueous phase are obtained; S205, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum, and obtaining an organic phase IV through countercurrent extraction in a 10-stage extraction tank; S206, combining organic phase III with organic phase IV in an extraction tank to obtain organic phase V, and extracting with an anti-tantalate agent to obtain a high-purity fluorotantalate solution containing low antimony. The extraction stage is 16, and the volume ratio of organic phase V to anti-tantalate agent is 1:0.85. Embodiment 2:

[0025] S301, adjusting the high antimony tantalum-containing solution (the total amount of tantalum oxide and niobium oxide is 95 g / L, and the antimony content is 8.6×10-3 g / L) with hydrofluoric acid and sulfuric acid to a hydrofluoric acid concentration of 2.0 mol / L and a sulfuric acid concentration of 0.5 mol / L to obtain a tantalum-containing stock solution; S302, using MIBK as an extractant to perform countercurrent extraction with the tantalum-containing stock solution in an 8-stage extraction tank, with the volume ratio of the organic phase to the aqueous phase being 1:1.2, to obtain a tantalum-containing organic phase I; S303, 1.6 mol / L pickling agent is prepared with 98% analytical pure sulfuric acid, the volume ratio of organic phase I to pickling agent is 1:0.7, and the organic phase II is obtained by countercurrent washing in an 8-stage extraction tank; S304, using 0.55 mol / L reverse niobium agent prepared with 98% analytical pure sulfuric acid, the organic phase II and the reverse niobium agent are subjected to countercurrent extraction in a 10-stage extraction tank, the volume ratio of the organic phase II to the reverse niobium agent is 1:0.65, and an organic phase III and a fluoroniobate aqueous phase are obtained; S305, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum, and obtaining an organic phase IV through countercurrent extraction in a 10-stage extraction tank; S306, in an extraction tank, the organic phase III is combined with the organic phase IV to obtain an organic phase V, which is subjected to back extraction with a reverse tantalum agent to obtain a high-purity fluorotantalate solution containing low antimony. The extraction stage is 16, and the volume ratio of the organic phase V to the reverse tantalum agent is 1:0.85. Embodiment 3:

[0026] S401, adjusting the high antimony tantalum-containing solution (the total amount of tantalum oxide and niobium oxide is 85 g / L, and the antimony content is 9.5×10-3 g / L) with hydrofluoric acid and sulfuric acid to a hydrofluoric acid concentration of 2.2 mol / L and a sulfuric acid concentration of 0.4 mol / L to obtain a tantalum-containing stock solution; S402, using MIBK as an extractant to perform countercurrent extraction with the tantalum-containing stock solution in an 8-stage extraction tank, with the volume ratio of the organic phase to the aqueous phase being 1:1.2, to obtain a tantalum-containing organic phase I; S403, 1.7 mol / L pickling agent is prepared with 98% analytical pure sulfuric acid, the volume ratio of organic phase I to pickling agent is 1:0.7, and the organic phase II is obtained by countercurrent washing in an 8-stage extraction tank; S404, using 0.6 mol / L reverse niobium agent prepared with 98% analytical pure sulfuric acid, the organic phase II and the reverse niobium agent are subjected to countercurrent extraction in a 10-stage extraction tank, the volume ratio of the organic phase II to the reverse niobium agent is 1:0.65, and an organic phase III and a fluoroniobate aqueous phase are obtained; S405, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum, and obtaining an organic phase IV through countercurrent extraction in a 10-stage extraction tank; S406, in an extraction tank, the organic phase III is combined with the organic phase IV to obtain an organic phase V, which is stripped with a reverse tantalum agent to obtain a high-purity fluorotantalate solution containing low antimony. The extraction stage is 16, and the volume ratio of the organic phase V to the reverse tantalum agent is 1:0.85.

[0027] The high-purity fluorotantalate solutions obtained in the above three examples were respectively added with analytical pure ammonia water for precipitation to obtain three portions of high-purity tantalum hydroxide powder. The antimony content in the three portions of high-purity tantalum hydroxide powder was respectively analyzed and detected in accordance with the method described in T0567-2020. The results are as follows: Table 1 Sb / % Example 1 0.0003 Example 2 0.0002 Example 3 0.0004 By analyzing the detection data obtained in the above three groups of embodiments, it can be known that the high-purity fluorotantalate solution prepared by this method has a significantly reduced impurity content from 10 ppm to 2~4 ppm compared with the high-purity fluorotantalate solution prepared by the prior art.

[0028] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum- and antimony-containing solution, characterized in that: The following steps are involved: S101, adding an inorganic acid to the antimony-containing tantalum-containing solution in an extraction tank for modulation to adjust the acidity of the antimony-containing tantalum-containing solution so that the acidity gradient distribution in the extraction tank is the same as the predetermined acidity gradient distribution; S102, extracting the modulated antimony-containing and tantalum-containing solution with an organic solvent to allow metal ions to enter the organic phase to obtain an organic phase I, wherein the ratio of the organic solvent to the antimony-containing and tantalum-containing solution is a first predetermined ratio; S103, using a pickling agent to remove impurities in the organic phase I to obtain an organic phase II, wherein the ratio of the organic phase I to the pickling agent is a second predetermined ratio; S104, washing the organic phase II with a reverse niobium agent to obtain an organic phase III and a fluoroniobate aqueous phase, wherein the ratio of the organic phase II to the reverse niobium agent is a third predetermined ratio; S105, performing an organic extraction operation on the fluoroniobate aqueous phase to extract tantalum to obtain an organic phase IV; S106, combining organic phase III and organic phase IV in an extraction tank to obtain organic phase V, and then stripping organic phase V with a reverse tantalum agent to obtain a low-antimony high-purity fluorotantalate solution, wherein the ratio of organic phase V to the reverse tantalum agent is a fourth predetermined ratio.

2. The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution according to claim 1, characterized in that: In the antimony-containing tantalum-containing solution in step S101, the total amount of tantalum oxide and niobium oxide is 50-120 g / L, and the antimony content is 7×10 -3 ~12×10 -3 g / L.

3. The method for preparing a low-antimony high-purity fluorotantalate solution by using a tantalum-containing and antimony-containing solution as claimed in claim 1, characterized in that: The inorganic acid in step S101 is at least one of hydrofluoric acid and sulfuric acid.

4. The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution according to claim 1, characterized in that: The organic solvent used in step S102 is methyl isobutyl ketone or 2-octanol.

5. The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution according to claim 1, characterized in that: The pickling agent used in step S103 is a 1.0-2.5 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

6. The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution according to claim 1, characterized in that: The anti-niobium agent used in step S104 is a 0.4-0.9 mol / L sulfuric acid solution, wherein silicon and iron are ≤0.004 g / L.

7. The method for preparing a low-antimony high-purity fluorotantalate solution using a tantalum-containing and antimony-containing solution according to claim 1, characterized in that: The anti-tantalum agent used in step S106 is secondary pure water.

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