Method for preparing sodium hexafluoroantimonate by using antimony trioxide one-step method

Abstract

The invention discloses a method for preparing sodium hexafluoroantimonate by using an antimony trioxide one-step method, which comprises the following steps: slurrying and dissolving raw materials including antimony trioxide, sodium fluoride and hydrofluoric acid, and slowly adding hydrogen peroxide for reaction to obtain a sodium hexafluoroantimonate crude product; and concentrating, cooling and crystallizing the sodium hexafluoroantimonate crude product to obtain a sodium hexafluoroantimonate refined product. According to the method, sodium fluoride is used as a sodium source and a fluorine source, sodium hexafluoroantimonate can be obtained only through one-step reaction with an antimony source, no new substance is introduced into a system, the reaction process is greatly shortened, experimental errors and generation of intermediate products and by-products are reduced, and the method has the advantages of being high in reaction degree and the like.

Description

Technical Field

[0001] The invention belongs to the field of preparation of fine chemicals, and specifically relates to a process for preparing sodium hexafluoroantimonate by utilizing antimony trioxide in a one-step process. Background Art

[0002] my country is the country with the richest antimony resources in the world, with antimony reserves accounting for more than 55% of the global total. It is also the country with the highest antimony product production in the world. However, my country's antimony product exports are mainly concentrated in primary products such as antimony concentrate, metallic antimony and ordinary antimony trioxide, and the foreign exchange earning benefits of these products are relatively low. In contrast, most advanced antimony compounds need to rely on imports. Sodium hexafluoroantimonate, as a widely used antimony salt, is considered to be a fine chemical product with development potential. In-depth research and production of sodium hexafluoroantimonate can not only promote the deep processing and development and utilization of my country's rich antimony resources, but also have important significance for enhancing the added value and market competitiveness of antimony products.

[0003] Sodium hexafluoroantimonate (NaSbF6) is a deep-processed product of antimony. The pentavalent antimony and fluoride ions in sodium hexafluoroantimonate are combined by strong coordination bonds. This coordination makes the fluoride ions in a relatively stable state. Since the fluorine atom is similar in size to the hydrogen atom but has a stronger electronegativity, the introduction of fluorine will not significantly change the stereo configuration of the molecule, but will greatly change the electronegativity of the molecule, which makes it widely used in the chemical industry and the pharmaceutical field. In the chemical industry, sodium hexafluoroantimonate is mainly used to synthesize new catalysts, participate in the preparation of iron-aromatic compounds and initiation systems for active polymerization, synthesize thermally stable cationic photoinitiators, and serve as a raw material for synthesizing sulfonium salts and iodonium salts. In the pharmaceutical field, NaSbF6 can replace organic fluorides and has important commercial value. In addition, since the coordination of pentavalent antimony with fluoride ions is very stable and has biological inertness that does not participate in biological conversion, it will not have any adverse effects on organisms when used as a pharmaceutical intermediate, which makes NaSbF6 very suitable for drug conversion.

[0004] There are many methods for preparing sodium hexafluoroantimonate, such as preparing by reacting hexafluoroantimonic acid and antimony pentoxide, and preparing by sodium antimonate and sodium fluoride. According to the difference between the antimony source and the fluorine source, the preparation method of sodium hexafluoroantimonate is also different. The traditional process technology of preparing sodium hexafluoroantimonate using antimony trioxide, such as Chinese patent CN113072097A, first prepares sodium pyroantimonate using antimony trioxide and sodium hydroxide solution, and then prepares hexafluoroantimonic acid by mixing antimony trioxide, hydrofluoric acid and hydrogen peroxide, and finally prepares sodium hexafluoroantimonate using sodium pyroantimonate, hexafluoroantimonic acid and sodium carbonate. Since in this process, in order to ensure that each reaction can fully react, each reactant is excessive, which makes the remaining reactant impurities in the product more. And because the reaction process is more complicated, the impurities and by-products produced during the experiment are also more, and repeated tests may cause the prepared product purity to be lower. Summary of the invention

[0005] In view of the problems existing in the prior art, the purpose of the present invention is to provide a method for preparing sodium hexafluoroantimonate by using antimony trioxide in a one-step process. The method uses sodium fluoride as a sodium source and a fluorine source, and can obtain sodium hexafluoroantimonate only by reacting with an antimony source in a one-step process. No new substances are introduced into the system, the reaction process is greatly shortened, experimental errors, the generation of intermediates and by-products are reduced, and the method has the advantages of high reaction degree.

[0006] In order to achieve the above technical purpose, the present invention provides a method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide, wherein the raw materials including antimony trioxide, sodium fluoride and hydrofluoric acid are slurried and dissolved, and then hydrogen peroxide is slowly added to react to obtain a crude sodium hexafluoroantimonate product; the crude sodium hexafluoroantimonate product is concentrated, cooled and crystallized to obtain a fine sodium hexafluoroantimonate product.

[0007] The method quantitatively adds antimony trioxide (Sb2O3), sodium fluoride (NaF), hydrogen fluoride (HF), hydrogen peroxide (H2O2) and other raw materials into a reactor, stirs by a rotor, obtains a saturated solution containing sodium hexafluoroantimonate, and then obtains a sodium hexafluoroantimonate product through cooling crystallization, washing, filtering and drying. The technical scheme of the present invention has only one-step reaction, can accurately control each stage, ensure that the reaction is carried out completely, is conducive to reducing the error in the experiment, reduces the generation of intermediates and by-products, has high reaction degree and production efficiency, and the obtained sodium hexafluoroantimonate fine product has high purity. In addition, the present invention reduces the usage of hydrogen fluoride in hydrofluoric acid to a certain extent.

[0008] The reaction equation of the present invention is as follows:

[0009] Sb2O3+2NaF+2H2O2+10HF=2NaSbF6+7H2O;

[0010] Formula I.

[0011] The specific reaction equation for preparing hexafluoroantimonic acid in the prior art is as follows:

[0012] Sb2O3+2NaOH=2NaSbO2+H2O;

[0013] NaSbO2+H2O2=NaSbO3+H2O;

[0014] Sb2O3+2H2O2+12HF=2HSbF6+7H2O;

[0015] HSbF6+NaSbO3=NaSbF6+HSbO3;

[0016] 2HSbO3+Na2CO3=2NaSbO3+H2O+CO2;

[0017] Formula II.

[0018] Comparing the reaction formula, it can be seen that there are multiple continuous reaction processes in the prior art, and the generated by-products and excess reactants will affect the purity of the product sodium hexafluoroantimonate. Although the present invention uses antimony trioxide, hydrofluoric acid and hydrogen peroxide, the key difference of the present invention is that NaF is used instead of sodium hydroxide. In comparison, the advantage is that on the one hand, the one-step preparation of hexafluoroantimonic acid effectively reduces the by-products present in the reaction process, provides aspects for subsequent crystal purification, and improves the purity of the product; on the other hand, the use of NaF instead of sodium hydroxide reduces the corrosion of the reactants to the reactor during the reaction to a certain extent, and because the fluorine source comes from two substances, NaF and HF, the use of HF is reduced to a certain extent, and the safety of production is improved.

[0019] At the same time, the inventors found that by dissolving sodium fluoride, antimony trioxide and hydrofluoric acid and then slowly adding H2O2 to the slurry, it is possible to effectively ensure that the sodium fluoride and antimony trioxide react fully and improve the uniformity of the reaction. At the same time, it is possible to effectively prevent the local H2O2 concentration from being too high to produce other oxide byproducts, and to prevent the decomposition of H2O2 from causing waste.

[0020] As a preferred solution, the reaction conditions are: temperature of 90-100°C and time of 1-3h. r Gm Θ <0, the reaction can proceed spontaneously, and the reactants can be fully dissolved and slurried; and within the time of the present invention, the reaction can be fully carried out. The inventors found that within the temperature reaction of the present invention, the reaction temperature is appropriately increased, the degree of reaction is more complete, the remaining antimony trioxide content is less, and the purity of the prepared sodium hexafluoroantimonate is increased. The further preferred temperature is 95-100°C.

[0021] As a preferred solution, the molar ratio of antimony trioxide, sodium fluoride and hydrofluoric acid is 1: (2-2.25): (10-11.5); wherein the amount of hydrofluoric acid is calculated as hydrogen fluoride. The hydrofluoric acid of the present invention needs to be strictly controlled. When the amount is too low, the reaction cannot be fully carried out. When the amount is too high, it will volatilize in large quantities and cause corrosion to the reaction equipment. Sodium fluoride plays the role of providing fluorine and sodium sources in the reaction process. It has little effect on the final synthesis effect of sodium hexafluoroantimonate, but excessive use will affect the subsequent purification process of sodium hexafluoroantimonate. Too low an amount will lead to insufficient reaction. Therefore, the amount of sodium fluoride added should be appropriately excessive. It is further preferred that the molar ratio of antimony trioxide, sodium fluoride and hydrofluoric acid is 1: (2.15-2.25): (11-11.5).

[0022] As a preferred solution, the amount of hydrogen peroxide added is 2 to 2.25 times the molar amount of antimony trioxide. In the present invention, hydrogen peroxide is the key to oxidizing trivalent antimony to pentavalent antimony. When the amount is too low, oxidation cannot be completely achieved, resulting in a low yield of sodium hexafluoroantimonate; and when the amount is too high, the amount of sodium hydroxide solution used in the concentration process will be increased, and because H2O2 has a decomposition problem (the specific decomposition equation is as Formula III), the decomposed H2O2 cannot play an oxidizing role, so the amount of H2O2 added should be appropriately excessive. It is further preferred that the amount of hydrogen peroxide added is 2.15 to 2.25 times the molar amount of antimony trioxide.

[0023] 2H2O2=2H2O+O2;

[0024] Formula III.

[0025] As a preferred solution, the concentration of the hydrogen peroxide is 30-50% by mass, and the hydrogen peroxide is slowly added by dropwise addition, which is beneficial for controlling the degree of reaction.

[0026] As a preferred solution, the concentration temperature is 100-120° C. and the time is 3-5 hours.

[0027] As a preferred solution, sodium hydroxide solution is used to absorb the evaporated gas during the concentration process. The gas mainly absorbed is the HF gas volatilized during the reaction process, and the generated sodium fluoride can be recycled as a reaction reagent. The reaction equation is as shown in Formula IV.

[0028] HF+NaOH=NaF+H2O;

[0029] Formula IV.

[0030] As a preferred solution, the concentration of the sodium hydroxide solution is 1-2 mol / L.

[0031] As a preferred solution, the cooling crystallization time is 12 to 24 hours.

[0032] As a preferred solution, the purity of the refined sodium hexafluoroantimonate is greater than 90%, and the remaining amount of the reactant antimony trioxide accounts for less than 1.3%.

[0033] The present invention provides a one-step method for preparing sodium hexafluoroantimonate, which specifically comprises the following steps:

[0034] Step 1: Accurately weigh sodium fluoride and antimony trioxide according to the reaction ratio and transfer them into a polytetrafluoroethylene reactor.

[0035] Step 2: Accurately measure the hydrofluoric acid solution into the reaction kettle.

[0036] Step 3: Place the polytetrafluoroethylene reactor in an oil bath filled with glycerol, set the heating temperature, and keep the rotor stirring to ensure that all the reactants are slurried and dissolved.

[0037] Step 4: After the internal temperature of the reactor rises to the heating temperature, keep the system temperature unchanged, slowly add H2O2 solution to the reaction system, and continue stirring the reaction.

[0038] Step 5: After the stirring reaction is completed, the reaction system is heated up further, the reaction solution is concentrated, and the evaporated gas is absorbed multiple times using a NaOH solution.

[0039] Step 6: After cooling the concentrated reaction solution, the obtained solution containing hexafluoroantimonic acid crystals is filtered.

[0040] Step 7: Wash and dry the sodium hexafluoroantimonate crystals to obtain the final product.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] (1) The present invention optimizes experimental raw materials and experimental conditions, uses antimony trioxide as an antimony source, uses sodium fluoride as a sodium source and a fluorine source, and uses hydrogen fluoride as a fluorine source, thereby reducing the amount of hydrogen fluoride used to a certain extent, reducing the complexity of the experimental steps, improving the reaction efficiency while ensuring that the reactants react fully, simplifying the experimental steps, and achieving further economic and environmental protection.

[0043] (2) The present invention accurately controls the amount of hydrofluoric acid used in the reaction system, while ensuring that the reaction is fully carried out, reduces the volatilization of hydrofluoric acid and the corrosion of alkali solution to the reaction equipment, and effectively improves the cleanliness and environmental protection of the sodium hexafluoroantimonate production process.

[0044] (3) The one-step process for preparing sodium hexafluoroantimonate of the present invention significantly reduces the generation of by-products by precisely controlling the addition amount of reactants and reaction conditions, thereby ensuring efficient utilization of reactants. This process not only improves the purity of the product and reduces the impurity content, but also greatly improves the utilization rate of reactants, thereby optimizing the preparation process and improving product quality.

[0045] (4) The present invention has the advantages of stable effect, high production efficiency, simple process, etc. The raw materials involved in the process are simple and easy to obtain, and the prepared sodium hexafluoroantimonate product has high purity. The process is conducive to its large-scale industrial application.

[0046] (5) The sodium hexafluoroantimonate fine product prepared by the present invention can reach a purity of more than 90% without recrystallization. Under further preferred conditions, the purity can reach more than 93%. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a process flow chart for preparing sodium hexafluoroantimonate using antimony trioxide in one step.

[0048] Figure 2 XRD characterization of sodium hexafluoroantimonate prepared in Example 1.

[0049] Figure 3 XRD characterization of sodium hexafluoroantimonate prepared in Example 2. DETAILED DESCRIPTION

[0050] In order to better illustrate the embodiments of the present invention, the specific experimental schemes in the examples of the present invention are described clearly and completely below. The examples are only used to explain the present invention and do not constitute any limitation to the present invention. If no specific conditions are specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used without indicating the manufacturer are all conventional products that can be purchased commercially.

[0051] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0052] Example 1

[0053] This embodiment provides a one-step process for preparing sodium hexafluoroantimonate, and the specific steps are as follows:

[0054] Step 1: Transfer antimony trioxide, sodium fluoride and hydrofluoric acid accurately into a 500ml polytetrafluoroethylene reactor according to the reaction molar ratio of 1:2.15:11.

[0055] Step 2: Place the polytetrafluoroethylene reactor in an oil bath filled with glycerol, set the heating temperature to 90°C, and keep the rotor stirring to ensure that all the reactants are slurried and dissolved.

[0056] Step 3: After the internal temperature of the reactor rises to 90°C, keep the system temperature unchanged, slowly add a certain amount of 40% H2O2 solution to the reaction system, control Sb2O3:H2O2=1:2.15, and continue stirring the reaction for 2 hours.

[0057] Step 4: After the stirring reaction is completed, the reaction system is further heated to 110° C., the reaction solution is concentrated for 4 hours, and the evaporated waste gas is multiple-absorbed using a 1 mol / L NaOH solution.

[0058] Step 5: After cooling the concentrated reaction solution for 12 hours, the obtained solution containing hexafluoroantimonic acid crystals is filtered.

[0059] Step 6: Wash and dry the sodium hexafluoroantimonate crystals to obtain the final product.

[0060] Example 2

[0061] This embodiment provides a one-step process for preparing sodium hexafluoroantimonate, and the specific steps are as follows:

[0062] Step 1: Transfer antimony trioxide, sodium fluoride and hydrofluoric acid accurately into a 500ml polytetrafluoroethylene reactor according to the reaction molar ratio of 1:2.15:11.

[0063] Step 2: Place the polytetrafluoroethylene reactor in an oil bath filled with glycerol, set the heating temperature to 100°C, and keep the rotor stirring to ensure that all the reactants are slurried and dissolved.

[0064] Step 3: After the internal temperature of the reactor rises to 100°C, keep the system temperature unchanged, slowly add a certain amount of H2O2 solution to the reaction system, control Sb2O3:H2O2=1:2.15, and continue stirring the reaction for 2 hours.

[0065] Step 4: After the stirring reaction is completed, the reaction system is further heated to 110° C., the reaction solution is concentrated for 4 hours, and the evaporated waste gas is multiple-absorbed using a 1 mol / L NaOH solution.

[0066] Step 5: After cooling the concentrated reaction solution for 12 hours, the obtained solution containing hexafluoroantimonic acid crystals is filtered.

[0067] Step 6: Wash and dry the sodium hexafluoroantimonate crystals to obtain the final product.

[0068] Example 3

[0069] This embodiment provides a one-step process for preparing sodium hexafluoroantimonate, and the specific steps are as follows:

[0070] Step 1: Transfer antimony trioxide, sodium fluoride and hydrofluoric acid accurately into a 500ml polytetrafluoroethylene reactor according to the reaction molar ratio of 1:2:10.

[0071] Step 2: Place the polytetrafluoroethylene reactor in an oil bath filled with glycerol, set the heating temperature to 90°C, and keep the rotor stirring to ensure that all the reactants are slurried and dissolved.

[0072] Step 3: After the internal temperature of the reactor rises to 90°C, keep the system temperature unchanged, slowly add a certain amount of H2O2 solution to the reaction system, control Sb2O3:H2O2=1:2, and continue stirring the reaction for 2 hours.

[0073] Step 4: After the stirring reaction is completed, the reaction system is further heated to 110° C., the reaction solution is concentrated for 4 hours, and the evaporated waste gas is multiple-absorbed using a 1 mol / L NaOH solution.

[0074] Step 5: After cooling the concentrated reaction solution for 12 hours, the obtained solution containing hexafluoroantimonic acid crystals is filtered.

[0075] Step 6: Wash and dry the sodium hexafluoroantimonate crystals to obtain the final product.

[0076] Comparative Example 1

[0077] This embodiment provides a process for preparing sodium hexafluoroantimonate by a step-by-step method, which mainly includes two stages: stage one: preparation of sodium pyroantimonate, and stage two: preparation of sodium hexafluoroantimonate using sodium pyroantimonate. The specific steps are as follows:

[0078] Step 1: Transfer antimony trioxide and sodium hydroxide accurately into a 500 ml three-necked flask according to the reaction molar ratio of 1:2.5, set the water bath reaction temperature to 80°C, and maintain condensation reflux.

[0079] Step 2: Use a magnetic stirrer to stir and thoroughly mix the two reactants into a slurry.

[0080] Step 3: After the system is stable, slowly add 40% H2O2 by mass into the reaction system, keeping the dropping rate at 5 ml / min, and the amount of H2O2 added is to maintain Sb2O3:H2O2=1:2.5.

[0081] Step 4: After the reaction is complete and the temperature drops to room temperature, the slurry is filtered and washed with pure water to remove residual NaOH. The sample obtained by filtration is placed in an oven and dried at 100°C for 4 hours to obtain sodium pyroantimonate.

[0082] Step 5: Transfer sodium pyroantimonate and 100 ml ultrapure water into a 500 ml polytetrafluoroethylene reactor.

[0083] Step 6: Place the polytetrafluoroethylene reactor in an oil bath filled with glycerol, set the heating temperature to 90°C, and keep the rotor stirring to ensure that the sodium antimonate is fully slurried.

[0084] Step 7: After the internal temperature of the reactor rises to 100°C, keep the system temperature unchanged, add a certain amount of HF solution to the reaction system, control NaSbO3:HF=1:6.5, and continue stirring the reaction for 2 hours.

[0085] Step 8: After the stirring reaction is completed, the reaction system is further heated to 110° C., the reaction solution is concentrated for 4 hours, and the evaporated waste gas is multiple-absorbed using a 1 mol / L NaOH solution.

[0086] Step 9: After cooling the concentrated reaction solution for 12 hours, the obtained solution containing hexafluoroantimonic acid crystals is filtered.

[0087] Step 10: Wash and dry the sodium hexafluoroantimonate crystals to obtain the final product.

[0088] The difference between Example 1 and Example 2 is that the reaction temperature condition of Example 1 is 90° C., and the reaction temperature condition of Example 2 is 100° C. The difference between Example 3 and Example 1 is that the addition ratio of the reactants is changed. Comparative Example 1 is a process for preparing sodium hexafluoroantimonate using a step-by-step method, that is, sodium pyroantimonate is first prepared and then sodium hexafluoroantimonate is prepared.

[0089] In order to check the completeness of the reaction, the trivalent antimony and pentavalent antimony in the sample were quantitatively analyzed by cerium sulfate titration; the sodium hexafluoroantimonate synthesized in Examples 1 and 2 was characterized by an X-ray diffractometer (Empyrean 2); and all elements in the samples of Examples 1 and 2 were analyzed by an inductively coupled plasma emission spectrometer (ICAP7400radial).

[0090] The principle of the cerium sulfate titration method for determining antimony is: using cerium sulfate as a strong oxidant, under acidic conditions, the cerium ion (Ce 4+ ) and antimony ions (Sb 3+ ) The following reaction occurs:

[0091] 2Ce 4+ +Sb 3+ =2Ce 3+ +Sb 5+

[0092] Ce in reaction 4+ Reduced to Ce 3+ , and Sb 3+ is oxidized to Sb 5+ In solution, Ce4+ It is orange-yellow, while Ce 3 + Then it is colorless. Using methyl orange as an indicator, when the orange-yellow color of the solution fades and becomes colorless, it indicates that the titration has reached the endpoint. By measuring the consumption of the cerium sulfate standard solution, the content of total antimony and trivalent antimony in the system can be calculated. The specific operation and calculation method are as follows:

[0093] (1) Analysis method of total antimony content

[0094] First, weigh 0.1g of sodium hexafluoroantimonate sample (denoted as M), then add the sample to 20mL of concentrated sulfuric acid and heat until dissolved. Add 0.2g of Na2S to reduce the pentavalent antimony in the solution, and continue heating until the yellow color in the solution disappears completely. After the solution cools to room temperature, add 15mL of concentrated sulfuric acid, 20mL of concentrated hydrochloric acid and 100mL of deionized water again, and then heat to 80°C again. Under this condition, use methyl orange as an indicator and titrate with cerium sulfate standard solution. The antimony content in the sample can be calculated by the consumption of cerium sulfate standard solution. The specific calculation formula for total antimony is as follows:

[0095]

[0096] Where: W Sb —Mass percentage of total antimony in the sample;

[0097] C Ce(SO4)2 —Concentration of cerium sulfate standard solution, mol / L;

[0098] V—volume of cerium sulfate standard solution consumed in determining antimony, L;

[0099] M Sb —Molar mass of antimony, g / mol.

[0100] (2) Analysis method of trivalent antimony content

[0101] First, weigh 0.4g of sample (recorded as m), then add the sample to 20mL of concentrated sulfuric acid and heat to dissolve. After complete dissolution, add 15mL of concentrated sulfuric acid, 20mL of concentrated hydrochloric acid and 100mL of deionized water, and then heat the solution to 80°C again. Under this condition, use methyl orange as an indicator and titrate with cerium sulfate standard solution. The specific calculation formula of trivalent antimony is as follows:

[0102]

[0103] Where: W Sb3+ —Mass percentage of trivalent antimony in the sample;

[0104] C Ce(SO4)2—Concentration of cerium sulfate standard solution, mol / L;

[0105] v—volume of cerium sulfate standard solution consumed in determining antimony, L;

[0106] M Sb —Molar mass of antimony, g / mol.

[0107] Table 1 shows the contents of various indicators in the samples prepared in Examples 1 to 3 and Comparative Example 1. By comparing the data, it is found that the comparative data of Example 1 and Example 2 show that when the temperature of the reaction system is appropriately increased, the degree of reaction is relatively complete, the remaining trivalent antimony is less, that is, the content of antimony trioxide is less, and the purity of the prepared sodium hexafluoroantimonate is increased.

[0108] Example 3 shows that when the excess coefficient of the reactant addition amount during the preparation process is small, the reaction process is incomplete due to the volatilization of HF and the decomposition of H2O2 in the reaction, resulting in an increase in the content of trivalent antimony and a slight decrease in product purity.

[0109] Comparative Example 1 uses sodium hexafluoroantimonate prepared by a step-by-step method, and the reactants are in excess in each step, so the total antimony content in the sodium hexafluoroantimonate decreases. In addition, sodium metaantimonite (NaSbO2) is produced as a byproduct during the preparation of sodium pyroantimonate, which increases the content of trivalent antimony in the final product, and the product yield decreases due to the cumbersome process of the step-by-step method.

[0110] Table 1 Purity analysis of sodium hexafluoroantimonate samples prepared in Examples 1 to 3 and Comparative Example 1

[0111] sample Total antimony content (%) Trivalent antimony content (%) purity(%) Yield (%) Example 1 46.32 0.043 93.41 99.91 Example 2 46.79 0.036 94.48 99.92 Example 3 46.06 1.262 90.42 97.26 Comparative Example 1 42.34 3.462 78.51 91.82

[0112] Figure 2 and Figure 3 The XRD analysis results of the sodium hexafluoroantimonate prepared in Example 1 and Example 2 respectively show that the peak shape of the prepared sodium hexafluoroantimonate crystals is relatively complete, the characteristic peaks are sharp, the impurity peaks are relatively few, and the degree of consistency with the standard peaks of sodium hexafluoroantimonate is relatively high.

[0113] Table 2 is the ICP full element analysis results of various elements in the samples prepared in Example 1 and Example 2. The data show that the prepared sodium hexafluoroantimonate has a low impurity content without recrystallization, and the purity of the prepared product is high.

[0114] Table 2 Full element analysis results of sodium hexafluoroantimonate samples prepared in Examples 1 and 2 (unit: mg / L)

[0115]

[0116]

[0117] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide, characterized in that: The raw materials including antimony trioxide, sodium fluoride and hydrofluoric acid are slurried and dissolved, and then hydrogen peroxide is slowly added to react to obtain a crude sodium hexafluoroantimonate product; the crude sodium hexafluoroantimonate product is concentrated, cooled and crystallized to obtain a fine sodium hexafluoroantimonate product.

2. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 1, characterized in that: The reaction conditions are: temperature of 90-100° C. and time of 1-3 h.

3. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 2, characterized in that: The molar ratio of antimony trioxide, sodium fluoride and hydrofluoric acid is 1:(2-2.25):(10-11.5); wherein the amount of hydrofluoric acid is calculated as hydrogen fluoride.

4. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 3, characterized in that: The amount of hydrogen peroxide added is 2 to 2.25 times the molar amount of antimony trioxide.

5. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 4, characterized in that: The mass concentration of the hydrogen peroxide is 30-50%, and the hydrogen peroxide is slowly added in a dropwise manner.

6. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 1, characterized in that: The concentration temperature is 100-120° C. and the concentration time is 3-5 hours.

7. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 6, characterized in that: In the concentration process, sodium hydroxide solution is used to absorb the evaporated gas.

8. The method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to claim 1, characterized in that: The cooling crystallization time is 12 to 24 hours.

9. A method for preparing sodium hexafluoroantimonate by one-step method using antimony trioxide according to any one of claims 1 to 8, characterized in that: The purity of the refined sodium hexafluoroantimonate is greater than 90%, and the remaining amount of the reactant antimony trioxide accounts for less than 1.3%.

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