A method for removing silicon from ammonium perrylate

Abstract

This application relates to the technical field of ammonium perrylate purification, specifically disclosing a method for removing silicon from ammonium perrylate. The method includes the following steps: S1, electrifying a solution containing ammonium perrylate to obtain a primary perrylate solution in the region between the positive electrode and the anion exchange membrane; S2, heating the primary perrylate solution to 40-70°C, adding ammonia water or ammonia gas, stirring at high speed, then rapidly cooling to 0-4°C, and passing it through a filter membrane to obtain a secondary perrylate solution; S3, evaporating and concentrating the secondary perrylate solution, then adding ammonia water or ammonia gas to obtain a purified ammonium perrylate solution, and then freezing, crystallizing, filtering, and drying the purified ammonium perrylate solution to obtain high-purity ammonium perrylate. The ammonium perrylate obtained by the method of this application has the advantages of high purity and a silicon impurity content of less than 2 ppm.

Description

Technical Field

[0001] This application relates to the technical field of ammonium perrylate purification, and more specifically, it relates to a method for removing silicon from ammonium perrylate. Background Technology

[0002] Rhenium (Re) is a rare and dispersed metal with an extremely high melting point of 3180℃. Due to its high heat resistance, high corrosion resistance, and high hardness, rhenium has been widely used, such as in the manufacture of high-temperature alloys for aerospace and as reforming catalysts for petroleum catalytic cracking in the petrochemical industry. Since 2010, global rhenium resources have experienced a situation where demand exceeds supply, with the demand for rhenium resources increasing year by year.

[0003] Industrially, ammonium perrylate (NH4ReO4) is the main raw material for preparing metallic rhenium. It appears as white hexagonal bipyramidal crystals. The purity of ammonium perrylate plays a decisive role in the purity of rhenium products, and the purity of metallic rhenium directly affects its application performance; products prepared from low-purity ammonium perrylate cannot meet the requirements of aerospace and other fields. Currently, the main purification methods for crude ammonium perrylate include ion exchange and extraction.

[0004] Existing technologies also disclose some techniques for purifying high-purity ammonium perrylate. For example, application CN 106745293 A discloses a method for preparing high-purity ammonium perrylate. This method involves adding 5-20% ammonia water to crude ammonium perrylate for evaporation and concentration, resulting in a perrylate concentration of 15-25 g / L. Then, 0.5-5 g of ammonium perrylate seed crystals are added to the concentrated solution, and the solution is centrifuged at 500-2000 rpm. The centrifuged ammonium perrylate solution is then placed in a crystallizer, and 0.5-5 mg of ammonia is added simultaneously. 2 Glass beads were collected and placed at room temperature for 20-30 hours; the above solution was then subjected to solid-liquid separation to obtain ammonium perrylate product; the above process was repeated 2-3 times to obtain the product.

[0005] However, the above method has a problem: the silicon in the ammonium rhenium oxide solution exists in the forms of colloidal silicon and active silicon. Silicate compounds existing in water in ionic or monomolecular form are called active silicon, while those existing in water in a multimolecular aggregate state are called colloidal silicon due to their colloidal properties. Colloidal silicon in water exists as a polymer; these long-chain compounds do not possess charged ionic properties and therefore cannot be removed by ion exchange or other purification methods. Consequently, the silicon content in the resulting ammonium rhenium oxide solution is difficult to reduce to below 2 ppm.

[0006] Therefore, it is necessary to purify ammonium perrylate to obtain a significantly reduced silicon content, and it is very important to prepare ammonium perrylate by a method that reduces the introduction of impurities and significantly reduces the silicon content in ammonium perrylate. Summary of the Invention

[0007] In order to obtain ammonium perrylate with a silicon content of less than 2 ppm, this application provides a method for removing silicon from ammonium perrylate. This method can effectively remove silicon impurities without introducing additional impurities, so that the silicon impurity content in the obtained ammonium perrylate is not higher than 2 ppm.

[0008] This application provides a method for removing silicon from ammonium perlite, which employs the following technical solution:

[0009] A method for removing silicon from ammonium perrylate includes the following steps:

[0010] S1. Electrolyze the solution containing ammonium perrylate and allow the anions moving towards the positive electrode in the ammonium perrylate solution to pass through the anion exchange membrane to obtain a primary perrylate solution. At the same time, add perrylate to the area where the solution is to be treated to maintain the pH of the solution at 4-8.

[0011] S2. Heat the primary rhenium acid solution to 40-70℃, add ammonia gas or ammonia water, and stir at a high speed of 7000-1000 rpm. Then, pass the solution through a filter membrane to obtain a primary ammonium rhenium acid solution.

[0012] S3. The primary ammonium perrylate solution is evaporated and concentrated, and the concentrated solution is crystallized, filtered and dried to obtain high-purity ammonium perrylate.

[0013] The target compound, ammonium perrylate, is in an ionic state in solution. Therefore, removing colloidal silicon through solid-liquid separation is a viable approach when the silicon impurity is colloidal. Using the above technical solution, this application first applies an electric current to the ammonium perrylate solution, causing the cations in the solution to move towards the negative electrode (cathode) and the anions towards the positive electrode (anode). However, colloidal silicon does not contain any charge and can therefore be separated from the ammonium perrylate. In specific implementation, while treating the solution with electricity, the anions moving towards the positive electrode simultaneously pass through an anion exchange membrane; the use of this anion exchange membrane can remove ReO4... - To avoid secondary contamination of the resulting rhenium acid solution, it is separated from the liquid to be treated. During this process, due to continuous energization and continuous ion movement and ion exchange, the pH value of the area where the liquid to be treated is located increases significantly. When the pH is higher than 8, colloidal silica will directly exist in ionic form, making it difficult to separate the impurity silica and ammonium rhenium acid in this way. Therefore, rhenium acid is added to maintain the pH of the liquid to be treated at 4-8.

[0014] However, it should also be noted that electrolysis alone is not enough to reduce silicon impurities in the obtained ammonium perrylate to below 2 ppm. Therefore, further steps are needed to remove silicon impurities.

[0015] In subsequent processing steps, the rhenium acid passing through the anion exchange membrane has a pH of approximately 2.5. At this point, some silicon impurities still exist in the rhenium acid in an ionic state. After adding ammonia gas or ammonia water, an ammonium rheniumate solution is obtained. At this point, due to the pH change, the ionic silicon impurities in the ammonium rheniumate solution exist as colloidal silicon again, thus requiring further removal of silicon impurities. In step S2, this application first heats the solution to ensure that as many silicon impurities as possible exist in an ionic state, then adds ammonia water or ammonia gas, followed by high-speed stirring and cooling, causing the ionic silicon impurities to transform into colloidal silicon. It is important to note that the cooling and adding ammonia water or ammonia gas steps must be performed simultaneously with high-speed stirring to achieve the goal of reducing the silicon impurity content. The reason for this is that the cooling and adding ammonia water or ammonia gas steps, combined with high-speed stirring, require the dual effects of pH and temperature adjustment to convert ionic silicon impurities into colloidal silicon. High-speed stirring is a necessary auxiliary condition to promote the rapid and complete conversion of ionic silicon impurities into colloidal silicon, thereby significantly improving the silicon impurity removal rate.

[0016] This method does not introduce new ionic impurities, such as K and Na ions, during the purification of ammonium rhenium. Therefore, it can effectively control the subsequent crystallization process and prepare high-purity ammonium rhenium with a purity of at least 99.99% and a silicon impurity content of no more than 2 ppm.

[0017] Optionally, the anion exchange membrane is selected from amino-based anion exchange membranes or aromatic amino-based anion exchange membranes.

[0018] Optionally, the heating temperature in S2 is 40-50℃.

[0019] By adopting the above technical solution, the temperature is further optimized, at which the silicon impurities in the ammonium rheniumate solution exist in an ionic state; and at this temperature, it is convenient to rapidly cool to 0-4°C later, causing the silicon impurities to quickly transform into colloidal silicon. Optional rapid cooling methods, such as liquid nitrogen quenching, can achieve this.

[0020] Optionally, the stirring speed in S2 is 8000-1000 rpm.

[0021] Optionally, the temperature in S2 can be lowered to 0-4℃.

[0022] Optionally, the cooling time in S2 is 3-6 minutes.

[0023] By adopting the above technical solution and reducing the temperature to 0-4℃, the rapid cooling combined with the addition of ammonia water or ammonia gas and high-speed stirring of the ammonium rheniumate solution can significantly reduce the silicon impurity content, thereby significantly improving the silicon impurity removal rate.

[0024] By adopting the above technical solution, the high-speed stirring speed combined with rapid cooling can result in small colloidal silica particle size, thereby achieving a better adsorption effect on other metal impurities and reducing the content of other metal impurities in rhenium acid.

[0025] Optionally, the pore size of the filter membrane selected in S2 is 0.1-10 μm, and the membrane is selected from one or more of reverse osmosis membranes, ultrafiltration membranes, microporous filter membranes, etc.

[0026] Alternatively, in S2, when the solution is passed through the filter membrane, a multi-stage permeation membrane is used, employing 2 to 4 stages in series, with each stage having an effective membrane area ≥ 0.01 m². 2 .

[0027] Further optionally, when the multi-stage permeation membrane is a two-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥1μm, and the pore size of the second-stage permeation membrane is ≥0.1μm;

[0028] When the multi-stage permeation membrane is a three-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥5μm, the pore size of the second-stage permeation membrane is ≥1μm, and the pore size of the third-stage permeation membrane is ≥0.1μm.

[0029] When the multi-stage permeation membrane is a 4-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥10μm, the pore size of the second-stage permeation membrane is ≥5μm, the pore size of the third-stage permeation membrane is ≥1μm, and the pore size of the fourth-stage permeation membrane is ≥0.1μm.

[0030] Alternatively, the flow rate of the rhenium acid solution can be 1 L / h to 50 L / h, and the volume of a single filtration can be 20 L to 500 L.

[0031] Optionally, the mass ratio of crude ammonium permanganate to water in the solution to be treated in S1 is 1:(20-50).

[0032] Optionally, the purity of crude ammonium perrylate is 99-99.99 wt%.

[0033] Optionally, the silicon impurity content in the crude ammonium perrylate is ≥10 ppm; further optionally, the silicon impurity content in the crude ammonium perrylate is 10-1000 ppm.

[0034] Optionally, when S1 applies electricity to the liquid to be treated containing ammonium perrylate, the temperature of the liquid to be treated is maintained at 0-10℃.

[0035] By adopting the above technical solution, it is ensured that the silicon impurities in ammonium rhenium acid exist as colloidal silicon as much as possible when electricity is applied; otherwise, if a large number of silicon impurities escape into the rhenium acid in ionic form, it will be difficult to remove them effectively through subsequent steps.

[0036] Optionally, the purity of the added rhenium acid in S1 is 99-99.99 wt%.

[0037] In summary, this application has the following beneficial effects:

[0038] 1. In removing silicon impurities from ammonium permanganate, this application pre-removes some silicon and metal impurities by electrolysis, followed by heating a permanganate solution, adding ammonia, rapidly cooling, and high-speed stirring to significantly remove colloidal silicon impurities from ammonium permanganate.

[0039] 2. The heating temperature setting in this application fully considers the subsequent rapid cooling operation, and sets an appropriate and reasonable heating temperature, specifically 40-70℃, and further 40-50℃; and sets an appropriate stirring speed of 7000-10000rpm; so as to achieve the purpose of significantly reducing silicon impurities in ammonium rhenium through the cooperation of each step. Detailed Implementation

[0040] The present application will be further described in detail below with reference to the embodiments.

[0041] In this application, the electrostatic operation of treating a solution containing ammonium perrylate can be performed within a battery. The battery has a positive and a negative electrode on opposite sides, and an anion exchange membrane is located near the positive electrode. An inlet is provided between the anion exchange membrane and the negative electrode to allow the ammonium perrylate solution to enter. An outlet is provided between the anion exchange membrane and the positive electrode to allow the electrotreated perrylate to flow out. When the ammonium perrylate solution is introduced into the battery and energized, the anions (such as perrylate ions) in the ammonium perrylate solution move towards the positive electrode, while the cations (such as ammonium ions and other metal cations) move towards the negative electrode.

[0042] Example

[0043] Example 1

[0044] A method for removing silicon from ammonium perrylate includes the following steps:

[0045] S1, ammonium perrylate solution electrolysis

[0046] Preparation of the treatment solution containing ammonium perrylate: Take crude ammonium perrylate with a purity of 99.99 wt% and a silicon impurity content of 10 ppm. Mix the crude ammonium perrylate and water at a weight ratio of 1:20 to obtain the treatment solution containing ammonium perrylate. Cool the treatment solution to obtain a treatment solution with a temperature of 8±1℃.

[0047] The obtained solution to be treated is passed into a battery, and electricity is applied. Anions moving towards the positive electrode in the ammonium permanganate solution pass through an AMI-7001S anion exchange membrane to obtain a primary permanganate solution. Simultaneously, permanganate is added to the area containing the solution to be treated to maintain the pH of the solution within the range of 4-8. Furthermore, during the energizing process, the temperature of the solution to be treated in the energizing tank is maintained at 8±1℃ by placing the battery in cold water.

[0048] S2. After heating the primary rhenium acid solution to 40°C, ammonia water is added, and the mixture is stirred at a high speed of 7000 rpm for 5 minutes. Then, the temperature is lowered to 3±1°C within 3 minutes. The solution is then passed through a filter membrane at this temperature to obtain a primary ammonium rhenium acid solution. In this embodiment, a microporous filter membrane with a pore size of 0.1 μm and an effective membrane area of ​​0.01 m² is selected. 2 The flow rate of the primary rhenium acid solution is 1 L / h, and the volume of a single filtration is 20 L.

[0049] S3. The primary ammonium perrylate solution is evaporated and concentrated at normal pressure to 1 / 3 of the original volume. The concentrated solution is then frozen to crystallize, filtered, and dried to obtain high-purity ammonium perrylate.

[0050] Example 2

[0051] A method for removing silicon from ammonium perrylate includes the following steps:

[0052] S1, ammonium perrylate solution electrolysis

[0053] Preparation of the treatment solution containing ammonium perrylate: Take crude ammonium perrylate with a purity of 99.28 wt% and a silicon impurity content of 758 ppm. Mix the crude ammonium perrylate and water at a weight ratio of 1:35 to obtain the treatment solution containing ammonium perrylate. Cool the treatment solution to obtain a treatment solution with a temperature of 10 ± 1℃.

[0054] The obtained solution to be treated is passed into a battery, and electricity is applied. Anions moving towards the positive electrode in the ammonium perrylate solution pass through the Piperion electrode. TM An anion exchange membrane (Versogen brand) was used to obtain a primary rhenium acid solution. Simultaneously, rhenium acid was added to the area containing the solution to be treated to maintain the pH of the solution within the range of 4-8. Furthermore, during the energizing process, the temperature of the solution in the energizing tank was maintained at 10±1℃ by placing the battery in cold water.

[0055] S2. The primary rhenium acid solution is heated to 45°C, then ammonia gas is introduced, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes. The temperature is then lowered to 1±1°C within 4 minutes. The solution is then passed through a filter membrane at this temperature to obtain a primary ammonium rhenium acid solution. In this embodiment, a microporous filter membrane with a pore size of 0.1 μm and an effective membrane area of ​​0.1 m² is selected. 2 The flow rate of the primary rhenium acid solution is 25 L / h, and the volume of a single filtration is 350 L.

[0056] S3. The primary ammonium perrylate solution is evaporated and concentrated at normal pressure to 1 / 3 of the original volume. The concentrated solution is then frozen to crystallize, filtered, and dried to obtain high-purity ammonium perrylate.

[0057] Example 3

[0058] A method for removing silicon from ammonium perrylate includes the following steps:

[0059] S1, ammonium perrylate solution electrolysis

[0060] Preparation of the treatment solution containing ammonium perrylate: Take crude ammonium perrylate with a purity of 99.02 wt% and a silicon impurity content of 1000 ppm. Mix the crude ammonium perrylate and water at a weight ratio of 1:50 to obtain the treatment solution containing ammonium perrylate. Cool the treatment solution to obtain a treatment solution with a temperature of 0±1℃.

[0061] The obtained solution to be treated is passed into a battery, and electricity is applied. Anions moving towards the positive electrode in the ammonium perrylate solution pass through the Piperion electrode. TM An anion exchange membrane was used to obtain a primary rhenium acid solution. Simultaneously, rhenium acid was added to the area containing the solution to be treated to maintain the pH of the solution within the range of 4-8. Furthermore, during the energizing process, the temperature of the solution to be treated in the energizing tank was maintained at 0±1℃ by placing the battery in an ice-water mixture.

[0062] S2. The primary rhenium acid solution is heated to 70°C, then ammonia gas is introduced, and the mixture is stirred at 10,000 rpm for 3 minutes. The temperature is then lowered to 3±1°C within 6 minutes. The solution is then passed through a filter membrane at this temperature to obtain a primary ammonium rhenium acid solution. In this embodiment, a microporous filter membrane is used. Multi-stage filtration is employed, using a three-stage membrane osmosis combination. The pore size of the first-stage microporous filter membrane is 10 μm, the second-stage microporous filter membrane is 1 μm, and the third-stage microporous filter membrane is 0.2 μm. The effective membrane area of ​​each stage of the reverse osmosis membrane is 0.3 m². 2 The flow rate of the primary rhenium acid solution is 50 L / h, and the volume of a single filtration is 500 L.

[0063] S3. The primary ammonium perrylate solution is evaporated and concentrated at normal pressure to 1 / 3 of the original volume. The concentrated solution is then frozen to crystallize, filtered, and dried to obtain high-purity ammonium perrylate.

[0064] Example 4

[0065] The difference between this embodiment and Embodiment 2 is that the heating temperature in step S2 is different in this embodiment. Specifically, in S2, the primary rhenium acid solution is heated to 40°C, ammonia is added, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes; then the temperature is lowered to 1±1°C within 4 minutes, and the solution is passed through a filter membrane at a temperature of 1±1°C to obtain a primary ammonium rhenium acid solution. Everything else is the same as in Embodiment 2.

[0066] Example 5

[0067] The difference between this embodiment and Embodiment 2 is that the heating temperature in step S2 is different in this embodiment. Specifically, in S2, the primary rhenium acid solution is heated to 50°C, ammonia is added, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes; then the temperature is lowered to 1±1°C within 4 minutes, and the solution is passed through a filter membrane at a temperature of 1±1°C to obtain a primary ammonium rhenium acid solution. The rest is the same as in Embodiment 2.

[0068] Comparative Example 1

[0069] The difference between this embodiment and Embodiment 2 is that the heating temperature in step S2 is different in this embodiment. Specifically, in S2, the primary rhenium acid solution is heated to 70°C, ammonia is added, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes; then the temperature is lowered to 1±1°C within 4 minutes, and the solution is passed through a filter membrane at a temperature of 1±1°C to obtain a primary ammonium rhenium acid solution. The rest is the same as in Embodiment 2.

[0070] Comparative Example 2

[0071] The difference between this embodiment and Embodiment 2 is that the cooling rate in step S2 of this comparative example is different. Specifically, in S2, the primary rhenium acid solution is heated to 45°C, ammonia is added, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes. Then, the temperature is cooled to 1±1°C within 10 minutes. When the solution temperature is 1±1°C, the solution is passed through a filter membrane to obtain a primary ammonium rhenium acid solution.

[0072] Comparative Example 3

[0073] The difference between this comparative example and Example 2 is that the cooling temperature in step S2 of this comparative example is different. Specifically, in S2, the primary rhenium acid solution is heated to 45°C, ammonia is added, and the mixture is stirred at a high speed of 9000 rpm for 4 minutes; then the temperature is lowered to 10±1°C within 4 minutes, and the solution is passed through a filter membrane when the solution temperature is 1±1°C to obtain a primary ammonium rhenium acid solution. Everything else is the same as in Example 2.

[0074] Comparative Example

[0075] Comparative Example 1

[0076] The difference between this comparative example and Example 2 is that the heating temperature in step S2 of this comparative example is different. Specifically, in S2, ammonia gas is added to the primary rhenium acid solution at room temperature (27±2℃), and the mixture is stirred at a high speed of 9000 rpm for 4 minutes; then the temperature is lowered to 1±1℃ within 4 minutes, and the solution is passed through a filter membrane at a temperature of 1±1℃ to obtain a primary ammonium rhenium acid solution. The rest is the same as in Example 2.

[0077] Comparative Example 2

[0078] The difference between this comparative example and Example 2 is that the stirring speed in step S2 of this comparative example is different. Specifically, in S2, the primary rhenium acid solution is heated to 45°C, ammonia is added, and the mixture is stirred at a high speed of 5000 rpm for 4 minutes. Then, the temperature is lowered to 1±1°C within 4 minutes, and the solution is passed through a filter membrane when the solution temperature is 1±1°C to obtain a primary ammonium rhenium acid solution.

[0079] Comparative Example 3

[0080] The difference between this comparative example and Example 2 is that, in this comparative example, the heating, high-speed stirring, and rapid cooling steps of S2 are omitted when treating the ammonium perrylate solution. Specifically:

[0081] A method for removing silicon from ammonium perrylate includes the following steps:

[0082] S1. Electrostatic treatment of ammonium perrylate solution: This operation is the same as in Example 2.

[0083] S2. Add ammonia gas to the primary rhenium acid solution to obtain a primary ammonium rhenium acid solution.

[0084] S3. The primary ammonium perrylate solution is evaporated and concentrated at normal pressure to 1 / 3 of the original volume. The concentrated solution is then frozen to crystallize, filtered, and dried to obtain high-purity ammonium perrylate.

[0085] Comparative Example 4

[0086] The difference between this comparative example and Example 2 is that, in this comparative example, the step of energizing S1 is omitted when treating the ammonium perrylate solution. Specifically:

[0087] A method for removing silicon from ammonium perrylate includes the following steps:

[0088] S1. Preparation of the treatment solution containing ammonium perrylate: Take crude ammonium perrylate with a purity of 99.28 wt% and a silicon impurity content of 758 ppm. Mix the crude ammonium perrylate and water at a weight ratio of 1:35 to obtain the treatment solution containing ammonium perrylate.

[0089] S2. The solution to be treated is heated to 45°C and stirred at a high speed of 9000 rpm for 4 minutes; then cooled to 1±1°C within 4 minutes, and the solution is passed through a filter membrane at a temperature of 1±1°C to obtain a primary ammonium perrylate solution. The filter membrane is selected the same as in Example 2.

[0090] S3. The primary ammonium perrylate solution is evaporated and concentrated at normal pressure to 1 / 3 of the original volume. The concentrated solution is then frozen to crystallize, filtered, and dried to obtain high-purity ammonium perrylate.

[0091] Performance testing

[0092] 1. Ammonium perrylate purity test

[0093] The purity of ammonium perrylate was determined by the difference method, where the purity W = 100% - the total content of all impurities.

[0094] The method for detecting the content of various metal ions in ammonium perrylate: referring to the standard YS / T 833-2020, the content of each metal element impurity is measured by inductively coupled plasma atomic emission spectrometry.

[0095] 2. Determination of silicon impurity content in ammonium rhenium oxide: Refer to standard YS / T 1017-2015 and determine the silicon content using inductively coupled plasma mass spectrometry (ICP-MS) according to the rhenium powder standard.

[0096] Table 1. Purity of ammonium rheniumate and silicon impurity content obtained from different implementation schemes.

[0097]

[0098] Table 2. Content of metallic impurities in ammonium perrylate obtained from different implementation schemes.

[0099]

[0100]

[0101] The data in Tables 1 and 2 show that the ammonium rhenium oxide prepared by the method of this application has high purity, significantly reduced silicon impurity content, and significantly reduced metal impurity content.

[0102] By comparing Examples 2 and 4-5, Comparative Example 1, and Comparative Example 1, it was found that the heating temperature is crucial when heating the primary rhenium acid solution in S2, and a heating temperature range of 40-50°C is recommended. This may be because if the heating temperature is too low or there is no heating (i.e., room temperature treatment in Comparative Example 1), a small amount of silicon impurities in the rhenium acid exist in an ionic state, while some exist in a colloidal state. When ammonia water or ammonia gas is added to the rhenium acid along with high-speed stirring, these small amounts of ionic silicon impurities are difficult to fully transform into a colloidal state, resulting in a higher silicon impurity content in the final ammonium rhenate. However, when heated to a sufficiently high temperature, i.e., 40-70°C, the silicon impurities are fully transformed into an ionic state under the acidic conditions of rhenium acid. When conditions change, the ionic silicon impurities have sufficient motivation to fully transform into colloidal silicon impurities. However, the heating temperature should not be too high. This is because this heating step requires subsequent rapid cooling to achieve its effect: if the heating temperature is too high, rapid cooling will be difficult to achieve, resulting in insufficient impurities in the ionic silicon to fully transform into colloidal silicon, thus hindering the significant reduction in silicon impurity content. Therefore, a heating temperature range of 40-50℃ is recommended.

[0103] The results of Example 2 and Comparative Example 2 show that the cooling time is crucial during the cooling process. Rapid cooling provides sufficient impurities for ionic silicon impurities to fully transform into colloidal silicon impurities, thereby significantly reducing the silicon impurity content in ammonium rheniumate.

[0104] Furthermore, based on the data from Comparative Example 3, the recommended cooling temperature in S2 is 0-4°C; otherwise, it will significantly affect the silicon impurity content in ammonium rheniumate. The data from Comparative Example 2 also illustrates the importance of high-speed stirring during cooling. Therefore, the synergistic effect of heating the primary rhenium acid solution, high-speed stirring, adding ammonia water or ammonia gas, and rapid cooling is crucial. Only by combining these operations can a significant reduction in silicon impurity content be achieved.

[0105] The data from Comparative Examples 3 and 4 also reflect that simply applying an electric current or merely heating the liquid to be treated, followed by high-speed stirring and rapid cooling is insufficient to significantly reduce the silicon impurity content in ammonium rhenium oxide. In this application, the method first removes a large amount of metallic impurities and a certain amount of ionic silicon impurities through an electric current treatment, and then further removes the remaining silicon impurities through heating the liquid to be treated, high-speed stirring, and rapid cooling, in order to obtain ammonium rhenium oxide with a silicon impurity content of less than 2 ppm.

[0106] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.

Claims

1. A method for removing silicon from ammonium perrylate, characterized in that, Includes the following steps: S1. Electrolyze the solution containing ammonium perrylate and allow the anions moving towards the positive electrode in the ammonium perrylate solution to pass through the anion exchange membrane to obtain a primary perrylate solution. At the same time, add perrylate to the area where the solution is to be treated to maintain the pH of the solution at 4-8. S2. Heat the primary rhenium acid solution to 40-70℃, add ammonia gas or ammonia water, and stir at a high speed of 7000-10000 rpm. After the reaction, stir at a high speed to cool down to 0-4℃, and then let the solution pass through a filter membrane to obtain a primary ammonium rhenium acid solution. S3. The primary ammonium perrylate solution is evaporated and concentrated, and the concentrated solution is crystallized, filtered and dried to obtain high-purity ammonium perrylate.

2. The method for removing silicon from ammonium perrylate according to claim 1, characterized in that, The anion exchange membrane is selected from amino-based anion exchange membranes or aromatic amino-based anion exchange membranes.

3. The method for removing silicon from ammonium perrylate according to claim 1, characterized in that, The heating temperature in S2 is 40-50℃.

4. The method for removing silicon from ammonium perlite according to claim 1, characterized in that, The stirring speed in S2 is 8000-10000 rpm.

5. The method for removing silicon from ammonium perrylate according to claim 1, characterized in that, The pore size of the filter membrane selected in S2 is 0.1-10μm, and the membrane is selected from one or more of reverse osmosis membranes, ultrafiltration membranes, and microporous filter membranes.

6. The method for removing silicon from ammonium perrylate according to claim 1, characterized in that, In S2, the solution is filtered through a multi-stage permeable membrane, and 2-4 stages are combined in series, with a single-stage effective membrane area ≥ 0.01 m 2 ; When the multi-stage permeation membrane is a two-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥1μm, and the pore size of the second-stage permeation membrane is ≥0.1μm; When the multi-stage permeation membrane is a three-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥5μm, the pore size of the second-stage permeation membrane is ≥1μm, and the pore size of the third-stage permeation membrane is ≥0.1μm. When the multi-stage permeation membrane is a 4-stage membrane permeation combination, the pore size of the first-stage permeation membrane is ≥10μm, the pore size of the second-stage permeation membrane is ≥5μm, the pore size of the third-stage permeation membrane is ≥1μm, and the pore size of the fourth-stage permeation membrane is ≥0.1μm.

7. The method for removing silicon from ammonium perrylate according to claim 1, characterized in that, When S1 applies electricity to the solution containing ammonium perrylate, the temperature of the solution is maintained at 0-10℃.

8. The method for removing silicon from ammonium perlite according to claim 1, characterized in that, The rhenium acid added to S1 has a purity of 99-99.99 wt%.

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