Preparation method of potassium fluozirconate
By using zirconium alkoxide precursors and choline glycine-based ionic liquids in the preparation of potassium fluorozirconate, the problems of difficulty in controlling particle size and using toxic substances in traditional methods are solved, and efficient and environmentally friendly preparation of potassium fluorozirconate is achieved.
Patent Information
- Application Number
- CN202510274261.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-10
- Publication Date
- 2025-04-25
AI Technical Summary
The traditional preparation method for potassium fluorozirconate has problems such as difficulty in controlling particle size, harsh reaction conditions and the use of toxic hydrogen fluoride, making it difficult to achieve efficient, environmentally friendly and precisely regulate nanoparticle size preparation.
The zirconium alkoxide precursor is mixed with ethanol, and the deionized water of the catalyst is added to hydrolyze to form a stable sol. Then potassium fluoride is added to dissolve in the ionic liquid and the reaction is heated up, and the reaction conditions are controlled to obtain nano-sized potassium fluorozirconate.
The formation of potassium fluorozirconate at a lower temperature is achieved, and a high purity (≥99%) potassium fluorozirconate with a particle size of ≤100nm is obtained, reducing production costs and environmental pollution, and no need to use toxic hydrogen fluoride.
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Figure CN119873885A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of inorganic synthesis, in particular to a method for preparing potassium fluorozirconate. Background Art
[0002] Potassium fluorozirconate is an important inorganic functional material, which is widely used in fireworks manufacturing, ceramic industry, nuclear energy protection, optical coating and catalyst carrier. Traditional preparation methods of potassium fluorozirconate mainly include hydrothermal method, molten salt method and direct precipitation method. However, these methods have the following shortcomings: Particle size control is difficult, and traditional processes easily lead to coarse product particle size (micrometer level) and uneven distribution, affecting performance; reaction conditions are harsh, and some methods require high-temperature sintering, which has high equipment requirements and high energy consumption; some methods require the use of hydrofluoric acid as a reaction raw material, and its strong corrosiveness, toxicity and potential environmental risks place high demands on operational safety.
[0003] Therefore, there is an urgent need to develop an efficient, environmentally friendly method for preparing potassium fluorozirconate that can precisely control the nanoparticle size. Summary of the invention
[0004] Purpose of the invention: In view of the above technical problems, the present invention proposes a method for preparing potassium fluorozirconate.
[0005] The technical solutions adopted are as follows: A method for preparing potassium fluorozirconate is as follows: (1) mixing a zirconium alkoxide precursor with ethanol, then adding deionized water containing a catalyst, stirring and hydrolyzing to form a stable sol; (2) dissolving potassium fluoride in an ionic liquid and adding the solution to the sol, sealing the solution, heating the solution to 110-130° C., stirring and reacting the solution for 1-10 hours; (3) After the reaction is completed, return to room temperature and centrifuge, collect the precipitate, wash it, and dry it to obtain potassium fluorozirconate.
[0006] Furthermore, the zirconium alkoxide precursor is tetrapropyl zirconate or tetrabutyl zirconate.
[0007] Furthermore, the catalyst is any one of nitric acid, acetic acid or citric acid.
[0008] Furthermore, the hydrolysis temperature is 10-40°C.
[0009] Furthermore, the ionic liquid is a choline amino acid ionic liquid.
[0010] Furthermore, the choline amino acid ionic liquid is prepared from choline hydroxide and glycine.
[0011] Furthermore, the preparation method of the choline amino acid ionic liquid is as follows: Glycine is dissolved in deionized water, and then choline hydroxide is added. After stirring for 10-20 hours, water is removed by vacuum distillation. Subsequently, a mixed solvent consisting of methanol and acetonitrile is added, and after sufficient stirring, the precipitate is filtered out and the filtrate is vacuum distilled to obtain a choline amino acid ionic liquid.
[0012] Furthermore, the reaction temperature is 10-40°C.
[0013] Furthermore, the mass ratio of the zirconium alkoxide precursor, ethanol, deionized water and ionic liquid is 2-4:20-30:5-10:10-15.
[0014] Furthermore, the particle size of the potassium fluorozirconate is ≤100 nm.
[0015] The present invention provides a method for preparing potassium fluorozirconate, which has the following beneficial effects: (1) Choline amino acid ionic liquids can catalyze the formation of potassium fluorozirconate at lower temperatures. The carboxyl and amino groups of the glycine anion can form coordination complexes with the zirconium ion, stabilize the intermediate state, and reduce the activation energy of the fluoride ion inserting into the zirconium oxygen bond. The hydroxyl group of the choline cation may interact with the fluoride ion through hydrogen bonds, enhancing its nucleophilicity and promoting its binding with the zirconium center, so that the reactants are in close contact on a microscopic scale and the catalytic reaction proceeds. (2) The choline glycine ionic liquid is composed of polar choline cations and glycine anions, which highly match the polarity of ionic potassium fluoride. The carboxyl group of the glycine anion and the hydroxyl group of the choline cation can form a hydrogen bond network with the fluoride ion, weakening the ionic bond between the potassium ion and the fluoride ion, improving the degree of dissociation, and increasing the solubility of potassium fluoride in the ionic liquid. The high polarity and low interfacial tension of the ionic liquid can form a nano-confinement effect, so that the prepared potassium fluorozirconate has a nano-sized particle size; (3) The choline amino acid ionic liquid used is non-toxic and highly biodegradable. It can replace traditional toxic solvents and reduce environmental pollution. After the reaction, the ionic liquid can be recovered and reused by distillation, which reduces the production cost. It does not require complex equipment or multiple purification steps. After centrifugation, a high-purity product (purity ≥ 99%) can be directly obtained. It does not need to use toxic hydrogen fluoride, which is safer, more environmentally friendly, and more suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 This is the SEM image of potassium fluorozirconate prepared in Example 1. DETAILED DESCRIPTION
[0017] If the specific conditions are not specified in the examples, the experiments were carried out under conventional conditions or the conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments is not specified, they are all conventional products that can be purchased commercially. The techniques not mentioned in the present invention are all referenced to the prior art. Unless otherwise specified, the following examples and comparative examples are parallel experiments, using the same processing steps and parameters.
[0018] Embodiment 1: A method for preparing potassium fluorozirconate: ZrO2 sol + 6KF + 2H2O → K2ZrF6 + 4KOH 3.84g of tetrabutyl zirconate was mixed with 25ml of ethanol to obtain solution A, 0.01g of citric acid was added to 8ml of deionized water to obtain solution B, solution B was slowly added dropwise to solution A, and then stirred and hydrolyzed at 30°C for 30min to form a stable sol, 3.48g of potassium fluoride was dissolved in 15g of choline glycine ionic liquid and then added dropwise to the above sol after appropriate heating, and after the addition, it was transferred to a hydrothermal reactor, sealed, heated to 110°C, stirred and reacted for 8h, and after the reaction was completed, it was restored to room temperature and centrifuged, the precipitate was collected, washed with deionized water and acetone, and then vacuum dried to obtain potassium fluorozirconate. The maximum particle size (D100) was measured by a laser image particle size analyzer and was ≤100nm. Its SEM image is shown in FIG. Figure 1 , yield 84.3%, purity ≥99%, and the product was confirmed to be potassium fluorozirconate by matching the diffraction peak position and intensity with the standard card.
[0019] The preparation method of choline glycine ionic liquid is as follows: 8 g of glycine was dissolved in 100 ml of deionized water, and then 12.1 g of choline hydroxide was added. After stirring at 25 °C for 15 h, water was removed by vacuum distillation. Subsequently, a mixed solvent consisting of 50 ml of methanol and 50 ml of acetonitrile was added and stirred thoroughly to precipitate the unreacted glycine. The mixture was filtered and the filtrate was again vacuum distilled to obtain choline glycine ionic liquid.
[0020] Embodiment 2: A method for preparing potassium fluorozirconate: ZrO2 sol + 6KF + 2H2O → K2ZrF6 + 4KOH 3.84 g of tetrabutyl zirconate was mixed with 25 ml of ethanol to obtain solution A, 0.01 g of citric acid was added to 8 ml of deionized water to obtain solution B, solution B was slowly added dropwise to solution A, and then stirred and hydrolyzed at 30°C for 30 min to form a stable sol, 3.48 g of potassium fluoride was dissolved in 15 g of cholineglycine ionic liquid and then added dropwise to the above sol after appropriate heating, and after the dropwise addition, the solution was transferred to a hydrothermal reactor, sealed, heated to 115°C, and stirred for reaction for 8 h. After the reaction was completed, the solution was centrifuged at room temperature, and the precipitate was collected, washed with deionized water and acetone, and then vacuum dried to obtain potassium fluorozirconate with a yield of 86.9% and a purity of ≥99%. The maximum particle size (D100) was ≤100 nm as measured by a laser image particle size analyzer, and the product was confirmed to be potassium fluorozirconate by matching the diffraction peak position and intensity with a standard card.
[0021] The preparation method of choline glycine ionic liquid is as follows: 8 g of glycine was dissolved in 100 ml of deionized water, and then 12.1 g of choline hydroxide was added. After stirring at 25 °C for 15 h, water was removed by vacuum distillation. Subsequently, a mixed solvent consisting of 50 ml of methanol and 50 ml of acetonitrile was added and stirred thoroughly to precipitate the unreacted glycine. The mixture was filtered and the filtrate was again vacuum distilled to obtain choline glycine ionic liquid.
[0022] Embodiment 3: A method for preparing potassium fluorozirconate: ZrO2 sol + 6KF + 2H2O → K2ZrF6 + 4KOH 3.84 g of tetrabutyl zirconate was mixed with 25 ml of ethanol to obtain solution A, 0.01 g of citric acid was added to 8 ml of deionized water to obtain solution B, solution B was slowly added dropwise to solution A, and then stirred and hydrolyzed at 30°C for 30 min to form a stable sol, 3.48 g of potassium fluoride was dissolved in 15 g of cholineglycine ionic liquid and then added dropwise to the above sol after appropriate heating, and after the dropwise addition, the solution was transferred to a hydrothermal reactor, sealed, heated to 120°C, and stirred for reaction for 8 h. After the reaction, the solution was centrifuged at room temperature, and the precipitate was collected, washed with deionized water and acetone, and then vacuum dried to obtain potassium fluorozirconate with a yield of 89.1% and a purity of ≥99%. The maximum particle size (D100) was ≤100 nm as measured by a laser image particle size analyzer, and the product was confirmed to be potassium fluorozirconate by matching the diffraction peak position and intensity with a standard card.
[0023] The preparation method of choline glycine ionic liquid is as follows: 8 g of glycine was dissolved in 100 ml of deionized water, and then 12.1 g of choline hydroxide was added. After stirring at 25 °C for 15 h, water was removed by vacuum distillation. Subsequently, a mixed solvent consisting of 50 ml of methanol and 50 ml of acetonitrile was added and stirred thoroughly to precipitate the unreacted glycine. The mixture was filtered and the filtrate was again vacuum distilled to obtain choline glycine ionic liquid.
[0024] Embodiment 4: A method for preparing potassium fluorozirconate: ZrO2 sol + 6KF + 2H2O → K2ZrF6 + 4KOH 3.84 g of tetrabutyl zirconate was mixed with 25 ml of ethanol to obtain solution A, 0.01 g of citric acid was added to 8 ml of deionized water to obtain solution B, solution B was slowly added dropwise to solution A, and then stirred and hydrolyzed at 30°C for 30 min to form a stable sol, 3.48 g of potassium fluoride was dissolved in 15 g of cholineglycine ionic liquid and then added dropwise to the above sol after appropriate heating, and after the dropwise addition, the solution was transferred to a hydrothermal reactor, sealed, heated to 125°C, and stirred for reaction for 8 h. After the reaction was completed, the solution was centrifuged at room temperature, and the precipitate was collected, washed with deionized water and acetone, and then vacuum dried to obtain potassium fluorozirconate with a yield of 91.2% and a purity of ≥99%. The maximum particle size (D100) was ≤100 nm as measured by a laser image particle size analyzer, and the product was confirmed to be potassium fluorozirconate by matching the diffraction peak position and intensity with a standard card.
[0025] The preparation method of choline glycine ionic liquid is as follows: 8 g of glycine was dissolved in 100 ml of deionized water, and then 12.1 g of choline hydroxide was added. After stirring at 25 °C for 15 h, water was removed by vacuum distillation. Subsequently, a mixed solvent consisting of 50 ml of methanol and 50 ml of acetonitrile was added and stirred thoroughly to precipitate the unreacted glycine. The mixture was filtered and the filtrate was again vacuum distilled to obtain choline glycine ionic liquid.
[0026] Embodiment 5: A method for preparing potassium fluorozirconate: ZrO2 sol + 6KF + 2H2O → K2ZrF6 + 4KOH 3.84 g of tetrabutyl zirconate was mixed with 25 ml of ethanol to obtain solution A, 0.01 g of citric acid was added to 8 ml of deionized water to obtain solution B, solution B was slowly added dropwise to solution A, and then stirred and hydrolyzed at 30°C for 30 min to form a stable sol, 3.48 g of potassium fluoride was dissolved in 15 g of cholineglycine ionic liquid and then added dropwise to the above sol after appropriate heating, and after the dropwise addition, the solution was transferred to a hydrothermal reactor, sealed, heated to 130°C, and stirred for reaction for 8 h. After the reaction was completed, the solution was centrifuged at room temperature, and the precipitate was collected, washed with deionized water and acetone, and then vacuum dried to obtain potassium fluorozirconate with a yield of 84.7% and a purity of ≥99%. The maximum particle size (D100) was ≤100 nm as measured by a laser image particle size analyzer, and the product was confirmed to be potassium fluorozirconate by matching the diffraction peak position and intensity with a standard card.
[0027] The preparation method of choline glycine ionic liquid is as follows: 8 g of glycine was dissolved in 100 ml of deionized water, and then 12.1 g of choline hydroxide was added. After stirring at 25 °C for 15 h, water was removed by vacuum distillation. Subsequently, a mixed solvent consisting of 50 ml of methanol and 50 ml of acetonitrile was added and stirred thoroughly to precipitate the unreacted glycine. The mixture was filtered and the filtrate was again vacuum distilled to obtain choline glycine ionic liquid.
[0028] Comparative Example 1: It is basically the same as Example 1, except that the choline glycine ionic liquid is replaced by deionized water of the same mass, and it is detected that no potassium fluorozirconate is generated.
[0029] Comparative Example 2: The method is basically the same as Example 1, except that the choline glycine ionic liquid is replaced by 1-butyl-3-methylimidazolium bromide of the same mass. Since 1-butyl-3-methylimidazolium bromide is difficult to dissolve potassium fluoride, an appropriate amount of deionized water is added to dissolve it. After detection, no potassium fluorozirconate is generated.
[0030] Comparative Example 3: is basically the same as Example 1, except that the choline glycine ionic liquid is replaced by the same mass of 1-butyl-3-methylimidazolium tetrafluoroborate, and since 1-butyl-3-methylimidazolium bromide is difficult to dissolve potassium fluoride, an appropriate amount of deionized water is added to dissolve it. It is detected that no potassium fluorozirconate is generated.
[0031] Comparative Example 4: is basically the same as Example 1, except that the choline glycine ionic liquid is replaced by the same mass of 1-butyl-3-methylimidazolium hexafluorophosphate. Since 1-butyl-3-methylimidazolium bromide is difficult to dissolve potassium fluoride, an appropriate amount of deionized water is added to dissolve it. It is detected that no potassium fluorozirconate is generated.
[0032] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for preparing potassium fluorozirconate, characterized in that: The details are as follows: (1) mixing a zirconium alkoxide precursor with ethanol, then adding deionized water containing a catalyst, stirring and hydrolyzing to form a stable sol; (2) dissolving potassium fluoride in an ionic liquid and adding the solution to the sol, sealing the solution, heating the solution to 110-130° C., stirring and reacting the solution for 1-10 hours; (3) After the reaction is completed, return to room temperature and centrifuge, collect the precipitate, wash it, and dry it to obtain potassium fluorozirconate.
2. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The zirconium alkoxide precursor is tetrapropyl zirconate or tetrabutyl zirconate.
3. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The catalyst is any one of nitric acid, acetic acid or citric acid.
4. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The hydrolysis temperature is 10-40°C.
5. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The ionic liquid is a choline amino acid ionic liquid.
6. The method for preparing potassium fluorozirconate according to claim 5, characterized in that: The choline amino acid ionic liquid is prepared from choline hydroxide and glycine.
7. The method for preparing potassium fluorozirconate according to claim 6, characterized in that: The preparation method of the choline amino acid ionic liquid is as follows: Glycine is dissolved in deionized water, and then choline hydroxide is added. After stirring for 10-20 hours, water is removed by vacuum distillation. Subsequently, a mixed solvent consisting of methanol and acetonitrile is added, and after sufficient stirring, the precipitate is filtered out and the filtrate is vacuum distilled to obtain a choline amino acid ionic liquid.
8. The method for preparing potassium fluorozirconate according to claim 7, characterized in that: The reaction temperature is 10-40°C.
9. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The mass ratio of the zirconium alkoxide precursor, ethanol, deionized water and ionic liquid is 2-4:20-30:5-10:10-15.
10. The method for preparing potassium fluorozirconate according to claim 1, characterized in that: The particle size of the potassium fluorozirconate is ≤100 nm.