A method for purifying and removing potassium from ammonium perrhenate

Abstract

The present invention discloses a method for purifying and removing potassium from ammonium perrhenate, comprising the following steps: mixing the ammonium perrhenate filtrate to be extracted with an organic phase, extracting to obtain a deeply depotassiumized ammonium perrhenate raffinate; wherein the organic phase is an organic matter after diluting the extractant; and extracting solid ammonium perrhenate from the ammonium perrhenate raffinate. The present invention uses a phosphorus extractant for solvent extraction, can quickly and selectively identify potassium ions in a complex system, deeply remove potassium ions from ammonium perrhenate, and reduce potassium ions in high-concentration ammonium perrhenate to the level of PPb, ensuring that the solution after potassium removal can evaporate and crystallize 99.99% or higher level of ammonium perrhenate, meeting the purity and low impurity requirements of various industries for ammonium perrhenate. The method provided by the present invention has the characteristics of short process flow, high product qualification rate, low production cost, simple operation, and easy industrial promotion.

Description

Technical Field

[0001] The invention relates to the field of separation and purification of scattered metals, and in particular to a method for purifying and removing potassium from ammonium perrhenate. Background Art

[0002] Metal rhenium has high melting point, high strength, high density, good plasticity and excellent mechanical stability. It has good creep resistance under high temperature and rapid cooling and heating conditions, and is suitable for ultra-high temperature and strong thermal shock working environment; it has very good thermal shock resistance at high temperature. At a high temperature of 2200℃, the engine nozzle made of rhenium can withstand 100,000 thermal fatigue cycles without failure. In addition, rhenium has very good wear resistance and corrosion resistance. Its wear resistance is second only to metal osmium, and it can maintain good chemical inertness for most fuel gases except oxygen. Due to its series of excellent properties, rhenium and its alloys are widely used in industries such as petrochemicals, aerospace and electronics, especially in some high-tech fields related to national security and national development strategies. It plays an irreplaceable role. It is precisely because of the rarity, irreplaceability and strategic nature of rhenium that it has received more and more attention. In the above-mentioned application of rhenium in various fields, high-purity ammonium perrhenate is generally used as raw material to produce various primary products such as high-purity rhenium powder, high-purity rhenium granules and high-purity rhenium bars, which are used to further produce various intermediate or terminal products containing rhenium. Since the main raw material for the preparation of 99.99% high-purity metallic rhenium is ammonium perrhenate with a purity of >99.99%, the preparation of high-purity ammonium perrhenate is an important prerequisite for the widespread application of rhenium. The efficient preparation of high-purity ammonium perrhenate from crude ammonium perrhenate or 99% ammonium perrhenate is of great significance for the application of rhenium. On April 30, 2018, the Chinese Nonferrous Industry Standard - Ammonium Perrhenate (YS / T894-2018) was issued. The standard stipulates that ammonium perrhenate is divided into three product types: qualified products, first-class products and superior products. Qualified products require an ammonium perrhenate content of no less than 99.0%; first-class products require an ammonium perrhenate content of no less than 99.90%, Pb and K contents no more than 40PPm, Ca, Fe, W and Na contents no more than 20PPm, Mo, Cu, Mg and Ni contents no more than 10PPm. It can be seen that this type of ammonium perrhenate has the lowest requirement for K in the monovalent ion phase, and potassium is one of the most difficult metal ions to remove; superior products increase the impurity content of six of K, Pb, Ca, Fe, W, Na and Mo to no more than 10PPm, and add two elements Sn and Mn. The contents of Sn, Mn, Ca, Mg and Ni do not exceed 5PPm.

[0003] When producing high-purity ammonium perrhenate, a small amount of K forms potassium perrhenate during the crystallization and evaporation process, and precipitates along with the ammonium perrhenate crystals, thereby increasing the difficulty of removing K from ammonium perrhenate, extending the process flow, increasing production costs, reducing product qualification rates, and increasing the loss of valuable element rhenium, making it one of the impurity elements that is difficult to remove in ammonium perrhenate products, thereby greatly increasing the difficulty of preparing high-purity ammonium perrhenate.

[0004] At present, the main processes for producing high-purity ammonium perrhenate include ion exchange purification, recrystallization purification and solvent extraction purification. In the related art, one method is to add crude ammonium perrhenate into ultrapure water to dissolve it, and then filter it through three-stage sieves in sequence to obtain a crude ammonium perrhenate solution, then add hydrogen peroxide and ammonia water, stir it, and then pass it through two series-connected gel acrylic cationic resins and gel sulfonic acid polystyrene cationic resins for adsorption to obtain a clean ammonium perrhenate solution, evaporate and concentrate, freeze crystallize, filter, and dry to obtain more than 99.99% ammonium perrhenate.

[0005] In another method, qualified (99.0%) ammonium perrhenate is used as the test raw material, and high-purity ammonium perrhenate is prepared by direct recrystallization and 732# and D001 ion exchange methods. However, the quality of the ammonium perrhenate products in the raw materials used can meet the standards of this batch of raw materials. 99.99% ammonium perrhenate can also be obtained by direct recrystallization process. However, if the product quality fluctuates greatly, ion exchange is required in the later stage, and the removal effect of K by this type of process cannot be confirmed. In the prior art, strong alkaline anion exchange resin is also used for ion exchange purification and impurity removal. Although it has strong adsorption capacity and high impurity removal rate, it is difficult to desorb rhenium and has poor selectivity.

[0006] In another method, the solution obtained by back-extraction of the N235 organic phase with hydrochloric acid is used as a raw material, chlorine is used to oxidize the low-valent rhenium element, and then saturated ammonium chloride is added to form a rhenium precipitate, and then the ammonium rhenate is purified. Since rhenium generally exists in the highest-valent state perrhenate in smelting waste acid, the use of chlorine oxidation technology narrows the application scope of this method. At the same time, the addition of ammonium chloride will introduce more chloride ions, which can easily lead to excessive anion chloride, making it difficult for the ammonium perrhenate content to meet the standard requirements.

[0007] It can be seen that the current industrial methods for producing high-purity ammonium perrhenate have the following main defects: (1) The product quality fluctuates greatly, and ion exchange is required in the later stage. It is impossible to confirm the removal effect of this type of process on K, so that qualified high-purity ammonium perrhenate cannot be obtained; (2) New impurity ions are introduced, making it difficult for the ammonium perrhenate content to meet the standard requirements (the preparation of 99.99% high-purity metallic rhenium requires ammonium perrhenate with a purity of >99.99%).

[0008] Considering that the commonly used industrial methods for producing high-purity ammonium perrhenate cannot meet our needs, the technical problem that technicians in this field need to solve urgently is: it is impossible to obtain high-purity ammonium perrhenate efficiently and effectively. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a method for purifying and removing potassium from ammonium perrhenate, comprising the following steps:

[0010] The ammonium perrhenate filtrate to be extracted is mixed with an organic phase, and extracted to obtain an ammonium perrhenate raffinate after potassium removal; wherein the organic phase is an organic matter after dilution of an extractant; wherein the extractant is any one of 2-ethylhexyl mono-2-ethylhexyl phosphate, di(2-ethylhexyl) phosphate or bis(2,4,4-trimethylpentyl) phosphoric acid;

[0011] Solid ammonium perrhenate is extracted from the ammonium perrhenate raffinate.

[0012] Preferably, the ammonium perrhenate filtrate is obtained by dissolving crude ammonium perrhenate with excessive potassium and then vacuum filtering it.

[0013] Preferably, extracting solid ammonium perrhenate from the ammonium perrhenate raffinate comprises:

[0014] performing an adsorption deoiling treatment on the ammonium perrhenate raffinate to obtain an ammonium perrhenate solution;

[0015] The ammonium perrhenate solution is evaporated and crystallized to obtain the solid ammonium perrhenate; wherein the crystallization temperature is 0-30°C.

[0016] Preferably, the volume percentage of the extractant to the organic phase is 5%-30%.

[0017] Preferably, the diluent used to dilute the extractant is kerosene.

[0018] Preferably, the volume ratio O / A of the organic phase to the ammonium perrhenate filtrate is 0.5-3.

[0019] Preferably, the crude ammonium perrhenate with excessive potassium has a purity of 99.0% qualified ammonium perrhenate or 99.9% first-class ammonium perrhenate.

[0020] Preferably, the obtained ammonium perrhenate raffinate is subjected to an adsorption deoiling treatment, comprising:

[0021] The obtained ammonium perrhenate raffinate is subjected to adsorption and oil removal treatment by resin column and / or activated carbon powder.

[0022] Preferably, the ammonium perrhenate solution is evaporated and crystallized to obtain ammonium perrhenate, comprising:

[0023] Concentrating the obtained ammonium perrhenate solution by liquid film evaporation;

[0024] The concentrated ammonium perrhenate solution is crystallized at low temperature to obtain the solid ammonium perrhenate.

[0025] Preferably, the obtained ammonium perrhenate solution is concentrated, comprising:

[0026] The volume of the ammonium perrhenate solution is concentrated to 5-20 times the volume of the original ammonium perrhenate solution.

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] The present invention discloses a method for purifying and removing potassium from ammonium perrhenate, comprising the following steps: mixing the ammonium perrhenate filtrate to be extracted with an organic phase, extracting to obtain a deeply depotassiumized ammonium perrhenate raffinate; wherein the organic phase is an organic matter after diluting the extractant; and extracting solid ammonium perrhenate from the ammonium perrhenate raffinate. The present invention uses a phosphorus extractant for solvent extraction, can quickly and selectively identify potassium ions in a complex system, deeply remove potassium ions from ammonium perrhenate, and reduce potassium ions in high-concentration ammonium perrhenate to the level of PPb, ensuring that the solution after potassium removal can evaporate and crystallize 99.99% or higher level of ammonium perrhenate, meeting the purity and low impurity requirements of various industries for ammonium perrhenate. The method provided by the present invention has the characteristics of short process flow, high product qualification rate, low production cost, simple operation, and easy industrial promotion.

[0029] The invention adopts phosphorus extractant 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P507) or di(2-ethylhexyl) phosphate (P204) or di(2,4,4-trimethylpentyl) phosphate (Cyanex272) to extract the solution. According to the cation exchange extraction theory, potassium ions in a complex system can be quickly and selectively identified, potassium ions in ammonium perrhenate can be deeply removed, and potassium ions in ammonium perrhenate can be reduced to the level of PPb (content of several parts per billion). In addition, the process and process parameters are optimized (extraction parameters, concentration multiples and adsorption oil removal treatment, etc.), so as to ensure that the solution after potassium removal can be evaporated and crystallized to produce ammonium perrhenate of 99.99% or higher level, meet the requirements of various industries for the purity and low impurities of ammonium perrhenate, meet the industrial demand for potassium removal of ammonium perrhenate, and adopt the method provided by the invention, which has the characteristics of short process flow, high product qualification rate, low production cost, simple operation, easy industrial promotion and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 The figure is a flow chart of the steps of the method for purifying and removing potassium from ammonium perrhenate in an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific examples, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the examples are conventional means well known to those skilled in the art. Unless otherwise specified, the examples, methods and equipment used in the present invention are conventional reagents, methods and equipment in the art.

[0032] At present, in the process of low-temperature crystallization to form ammonium rhenate in industry, a small amount of low-solubility potassium rhenate precipitates with the ammonium perrhenate crystals and is doped into the ammonium perrhenate product, thereby increasing the difficulty of removing impurities from the ammonium perrhenate, prolonging the process flow, increasing production costs, reducing product qualification rates, and increasing the loss of the valuable element rhenium, making it one of the most difficult impurity elements to remove in the ammonium perrhenate product, thereby greatly increasing the difficulty of preparing high-purity ammonium perrhenate.

[0033] Based on the above problems, the present invention proposes a solution for purifying and removing potassium from ammonium perrhenate, specifically: the present invention adopts a phosphorus extractant to perform cation exchange solvent extraction to remove potassium ions in the ammonium perrhenate, so that potassium ions in a complex system can be quickly and selectively identified, and potassium ions in high-concentration ammonium perrhenate can be reduced to the PPb level, thereby solving the current problems of difficulty in removing K from ammonium perrhenate, long process flow, low product qualification rate, high production cost, and high loss of valuable element rhenium.

[0034] The present invention provides a method for purifying and removing potassium from ammonium perrhenate, referring to Figure 1 As shown, a flow chart of the steps of the method for purifying and removing potassium from ammonium perrhenate of the present invention is shown, comprising the following steps:

[0035] Step S1: mixing the ammonium perrhenate filtrate to be extracted with an organic phase, and extracting to obtain an ammonium perrhenate raffinate after potassium removal; wherein the organic phase is an organic matter after diluting the extractant; wherein the extractant is any one of 2-ethylhexyl phosphate mono-2-ethylhexyl ester, di(2-ethylhexyl) phosphate or bis(2,4,4-trimethylpentyl) phosphoric acid;

[0036] Step S2: extracting solid ammonium perrhenate from the ammonium perrhenate raffinate.

[0037] In the embodiments of the present invention, the extractants 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P507), di(2-ethylhexyl) phosphate (P204) or di(2,4,4-trimethylpentyl) phosphate (Cyanex272) can be recycled, and the selected extractants are all common extractants in industry. Among them, di(2-ethylhexyl) phosphate (P204) can not only remove potassium, but also remove other cationic impurities.

[0038] In the embodiment of the present invention, the pH value of the solution to be extracted does not need to be adjusted because the pH of the original solution is about 5, and since the cation exchange extraction process has the best effect when pH ≥ 4, the pH value does not need to be adjusted during the exchange extraction process.

[0039] The steps of the method provided in the embodiment of the present invention are: preparation of ammonium perrhenate solution, selective deep extraction and removal of potassium in the ammonium perrhenate solution, deoiling of the purified liquid and evaporation crystallization. The invention adopts phosphorus extractant 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P507) or di(2-ethylhexyl) phosphate (P204) or di(2,4,4-trimethylpentyl) phosphate (Cyanex272) to extract the solution. According to the cation exchange extraction theory, potassium ions in a complex system can be rapidly and selectively identified, potassium ions in ammonium perrhenate can be deeply extracted and removed, potassium ions in high-concentration ammonium perrhenate can be reduced to the level of PPb (content of several parts per billion), and the process and process parameters of potassium removal (adsorption degreasing treatment, diluent, volume ratio and concentration multiple, etc.) are optimized to ensure that the solution after potassium removal can evaporate and crystallize to produce ammonium perrhenate of 99.99% or higher level, thereby reducing the loss of valuable element rhenium, and obtaining high-purity ammonium perrhenate efficiently (rapid selective identification) and effectively (deep removal after identification), thereby meeting the requirements of various industries for the purity and low impurities of ammonium perrhenate. In addition, the method provided by the present invention also has the characteristics of short process flow, high product qualification rate, low production cost, simple operation, and easy industrial promotion.

[0040] Preferably, the ammonium perrhenate filtrate is obtained by dissolving crude ammonium perrhenate with excessive potassium and then vacuum filtering it.

[0041] In the embodiment of the present invention, crude ammonium perrhenate with excessive potassium content is dissolved to prepare an ammonium perrhenate solution containing rhenium at a concentration of 10-40 g / L, and the solution is vacuum filtered to remove fine solid impurities (insoluble particles) to obtain an ammonium perrhenate filtrate.

[0042] In the embodiment of the present invention, high-purity water is used to dissolve the crude ammonium perrhenate product.

[0043] Preferably, extracting solid ammonium perrhenate from the ammonium perrhenate raffinate comprises:

[0044] performing an adsorption deoiling treatment on the ammonium perrhenate raffinate to obtain an ammonium perrhenate solution;

[0045] The ammonium perrhenate solution is evaporated and crystallized to obtain the solid ammonium perrhenate; wherein the crystallization temperature is 0-30°C.

[0046] In the embodiment of the present invention, the clean ammonium perrhenate solution is obtained by oil removal through adsorption.

[0047] Preferably, the volume percentage of the extractant to the organic phase is 5%-30%.

[0048] Preferably, the diluent used to dilute the extractant is kerosene.

[0049] In the embodiment of the present invention, adding a certain proportion of kerosene can change the concentration of the extractant, thereby adjusting the extraction performance of the extractant, so that potassium ions in ammonium perrhenate can be extracted and removed more efficiently during the extraction process.

[0050] Preferably, the volume ratio O / A of the organic phase to the ammonium perrhenate filtrate is 0.5-3.

[0051] Preferably, the crude ammonium perrhenate with excessive potassium has a purity of 99.0% qualified ammonium perrhenate or 99.9% first-class ammonium perrhenate.

[0052] In the embodiment of the present invention, since the ammonium perrhenate product has a lower impurity content and a higher ammonium perrhenate content, it is beneficial to increase the sample processing volume per unit volume or unit time. Therefore, the method provided by the present invention is suitable for qualified ammonium perrhenate with an ammonium perrhenate content of 99.0% (potassium content exceeds 40PPm) or first-class ammonium perrhenate with an ammonium perrhenate content of 99.9% (potassium content is not more than 40PPm).

[0053] Preferably, the obtained ammonium perrhenate raffinate is subjected to an adsorption deoiling treatment, comprising:

[0054] The obtained ammonium perrhenate raffinate is subjected to adsorption and oil removal treatment by resin column and / or activated carbon powder.

[0055] In the embodiment of the present invention, the reasons for performing adsorption deoiling treatment on the ammonium perrhenate raffinate are: on the one hand, a small amount of oil (extractant residue) remains in the residual water after extraction, which easily causes the carbon content of the crystalline ammonium perrhenate solid to exceed the standard; on the other hand, recovering the organic extractant in the raffinate phase can reduce the loss of expensive extractant and reduce production costs. In the present invention, how to perform adsorption deoiling treatment can be selected according to the characteristics of the ammonium perrhenate raffinate.

[0056] Preferably, the ammonium perrhenate solution is evaporated and crystallized to obtain ammonium perrhenate, comprising:

[0057] Concentrating the obtained ammonium perrhenate solution by liquid film evaporation;

[0058] The concentrated ammonium perrhenate solution is crystallized at low temperature to obtain the solid ammonium perrhenate.

[0059] In the embodiment of the present invention, a liquid film evaporation-rotary evaporation crystallizer is used to obtain ammonium perrhenate. The crystallization needs to be carried out at a low temperature (0-30° C.) to obtain solid ammonium perrhenate.

[0060] In the embodiment of the present invention, the crystallization mother liquor needs to be returned to the original liquor for cyclic extraction treatment, thereby effectively reducing the loss of the valuable element rhenium and ensuring the recovery rate of the valuable element rhenium.

[0061] In the embodiment of the present invention, due to evaporation, concentration and crystallization, the potassium concentration in the ammonium perrhenate solution in the crystallization mother liquor will be too high, which may make the obtained product unqualified. Therefore, the mother liquor after evaporation and crystallization can also be returned to the extraction and impurity removal system, which specifically includes: the mother liquor after evaporation and crystallization is returned to the extraction system for re-purification, thereby improving the recovery rate of the valuable element rhenium.

[0062] Preferably, the obtained ammonium perrhenate solution is concentrated, comprising:

[0063] The volume of the ammonium perrhenate solution is concentrated to 5-20 times the volume of the original ammonium perrhenate solution.

[0064] In the embodiment of the present invention, in order to obtain qualified ammonium rhenate and consider the cost, it is necessary to optimize the parameters of each stage of the process, including extraction parameters, concentration multiples and adsorption oil removal treatment, etc., wherein the extraction parameters include parameters such as volume ratio and concentration (the process in the present invention includes extraction stage, concentration stage, oil removal stage and crystallization stage).

[0065] In order to enable those skilled in the art to better understand the present invention, the method for purifying and removing potassium from ammonium perrhenate provided by the present invention is described below through multiple specific embodiments.

[0066] Example 1

[0067] 30 g of 99.0% crude ammonium perrhenate with a potassium content of 44 ppm was dissolved in 1 L of high-purity water to prepare an ammonium perrhenate solution, and the solution was vacuum filtered to remove fine solid impurities to obtain an ammonium perrhenate filtrate; the obtained ammonium perrhenate filtrate was mixed with an organic phase for extraction, and the volume ratio O / A of the organic phase (5% P507 and 95% 260# oil) to the ammonium perrhenate filtrate was 2 / 1, and the extraction was performed for 3 minutes. After phase separation, an ammonium perrhenate raffinate after potassium removal was obtained.

[0068] Activated carbon powder is added to the ammonium perrhenate raffinate at a solid-liquid ratio of 1 / 1000, and the mixture is fully stirred for adsorption and oil removal, and a clean ammonium perrhenate solution is obtained by solid-liquid separation; the obtained clean ammonium perrhenate solution is concentrated 10 times by liquid film evaporation, and the ammonium perrhenate is crystallized at 0°C to obtain 99.99% grade ammonium perrhenate.

[0069] Since high-purity ammonium perrhenate is an important raw material for preparing high-purity rhenium powder, the K ion content of ammonium perrhenate is reduced to PPb level in this embodiment, which meets the requirements for impurities (mainly K in the present invention) in high-purity ammonium perrhenate. The content of metallic rhenium in the prepared ammonium perrhenate remains basically unchanged. It is worth noting that the rhenium recovery rate is relatively high.

[0070] Example 2

[0071] 60 g of 99.0% crude ammonium perrhenate with a potassium content of 44 ppm was dissolved in 1 L of high-purity water to prepare an ammonium perrhenate solution, and the solution was vacuum filtered to remove fine solid impurities to obtain an ammonium perrhenate filtrate; the obtained ammonium perrhenate filtrate was mixed with an organic phase for extraction, and the volume ratio O / A of the organic phase (20% P204 and 80% 260# oil) to the ammonium perrhenate filtrate was 1 / 1, and the extraction was performed for 3 minutes. After phase separation, an ammonium perrhenate raffinate after potassium removal was obtained.

[0072] Activated carbon powder is added to the ammonium perrhenate raffinate at a solid-liquid ratio of 1 / 1000, and the mixture is fully stirred for adsorption and deoiling treatment, and a clean ammonium perrhenate solution is obtained by solid-liquid separation; the clean ammonium perrhenate solution is concentrated 5 times by liquid film evaporation, and the ammonium perrhenate is crystallized at a low temperature of 0°C to obtain 99.99% ammonium perrhenate.

[0073] Since high-purity ammonium perrhenate is an important raw material for preparing high-purity rhenium powder, the K ion content of ammonium perrhenate is reduced to PPb level in this embodiment, which meets the requirements for impurities (mainly K in the present invention) in high-purity ammonium perrhenate. The content of metallic rhenium in the prepared ammonium perrhenate remains basically unchanged. It is worth noting that the rhenium recovery rate is relatively high.

[0074] Example 3

[0075] 30 g of 99.0% crude ammonium perrhenate with a potassium content of 44 ppm was dissolved in 1 L of high-purity water to prepare an ammonium perrhenate solution, and the solution was vacuum filtered to remove fine solid impurities to obtain an ammonium perrhenate filtrate; the obtained ammonium perrhenate filtrate was mixed with an organic phase for extraction, and the volume ratio O / A of the organic phase (30% Cyanex272 and 70% 260# oil) to the ammonium perrhenate filtrate was 1 / 1, and the extraction was performed for 3 minutes. After phase separation, an ammonium perrhenate raffinate after potassium removal was obtained.

[0076] Activated carbon powder is added to the ammonium perrhenate raffinate solution b at a solid-liquid ratio of 1 / 1000, and the mixture is fully stirred for adsorption and oil removal, and a clean ammonium perrhenate solution is obtained by solid-liquid separation; the obtained clean ammonium perrhenate solution is concentrated 10 times by liquid film evaporation, and the ammonium perrhenate is crystallized at a low temperature of 30°C to obtain 99.99% grade ammonium perrhenate.

[0077] Since high-purity ammonium perrhenate is an important raw material for preparing high-purity rhenium powder, the K ion content of ammonium perrhenate is reduced to PPb level in this embodiment, which meets the requirements for impurities (mainly K in the present invention) in high-purity ammonium perrhenate. The content of metallic rhenium in the prepared ammonium perrhenate remains basically unchanged. It is worth noting that the rhenium recovery rate is relatively high.

[0078] Example 4

[0079] 50 g of 99.0% crude ammonium perrhenate with a potassium content of 44 ppm was dissolved in 1 L of high-purity water to prepare an ammonium perrhenate solution, and the solution was vacuum filtered to remove fine solid impurities to obtain an ammonium perrhenate filtrate; the obtained ammonium perrhenate filtrate was mixed with an organic phase for extraction, and the volume ratio O / A of the organic phase (30% P204 and 70% 260# oil) to the ammonium perrhenate filtrate was 1 / 1, and the extraction was performed for 3 minutes. After phase separation, an ammonium perrhenate raffinate after potassium removal was obtained.

[0080] Activated carbon powder is added to the ammonium perrhenate raffinate at a solid-liquid ratio of 1 / 1000, and the mixture is fully stirred for adsorption and oil removal, and a clean ammonium perrhenate solution is obtained by solid-liquid separation; the clean ammonium perrhenate solution is concentrated 20 times by liquid film evaporation, and the ammonium perrhenate is crystallized at a low temperature of 5°C to obtain 99.99% ammonium perrhenate.

[0081] Since high-purity ammonium perrhenate is an important raw material for preparing high-purity rhenium powder, the K ion content of ammonium perrhenate is reduced to PPb level in this embodiment, which meets the requirements for impurities (mainly K in the present invention) in high-purity ammonium perrhenate. The content of metallic rhenium in the prepared ammonium perrhenate remains basically unchanged. It is worth noting that the rhenium recovery rate is relatively high.

[0082] For the method embodiments, for the sake of simplicity, they are all described as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the order of the actions described, because according to the present invention, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and components involved are not necessarily required by the present invention.

[0083] The above is a detailed introduction to the method for purifying and removing potassium from ammonium perrhenate provided by the present invention. Specific examples are used herein to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for purifying ammonium perrhenate and removing potassium, characterized in that: The following steps are involved: The ammonium perrhenate filtrate to be extracted is mixed with an organic phase, and extracted to obtain an ammonium perrhenate raffinate after potassium removal; wherein the organic phase is an organic matter after diluting the extractant; wherein the extractant is any one of 2-ethylhexyl phosphate mono-2-ethylhexyl ester, di(2-ethylhexyl) phosphate or bis(2,4,4-trimethylpentyl) phosphoric acid; wherein the ammonium perrhenate filtrate is obtained by dissolving crude ammonium perrhenate with excessive potassium and vacuum filtering; the crude ammonium perrhenate with excessive potassium has a purity of 99.0% qualified ammonium perrhenate or 99.9% first-class ammonium perrhenate; the potassium content of the qualified ammonium perrhenate is greater than 40 PPm; the potassium content of the first-class ammonium perrhenate is not greater than 40 PPm; Solid ammonium perrhenate is extracted from the ammonium perrhenate raffinate; the solid ammonium perrhenate is 99.99% ammonium perrhenate; the potassium content in the solid ammonium perrhenate is PPb level; Extracting solid ammonium perrhenate from the ammonium perrhenate raffinate comprises: performing an adsorption deoiling treatment on the ammonium perrhenate raffinate to obtain an ammonium perrhenate solution; Evaporating and crystallizing the ammonium perrhenate solution to obtain the solid ammonium perrhenate; wherein the crystallization temperature is 0-30° C.; The obtained ammonium perrhenate raffinate is subjected to an adsorption deoiling treatment, comprising: The obtained ammonium perrhenate raffinate is subjected to adsorption and oil removal treatment by resin column and / or activated carbon powder; The ammonium perrhenate solution is evaporated and crystallized to obtain ammonium perrhenate, comprising: Concentrating the obtained ammonium perrhenate solution by liquid film evaporation; The concentrated ammonium perrhenate solution is crystallized at low temperature to obtain the solid ammonium perrhenate.

2. The method according to claim 1, characterized in that: The volume percentage of the extractant in the organic phase is 5%-30%.

3. The method according to claim 1, characterized in that The diluent for diluting the extractant is kerosene.

4. The method according to claim 1, characterized in that The volume ratio O / A of the organic phase to the ammonium perrhenate filtrate is 0.5-3.

5. The method according to claim 1, characterized in that The obtained ammonium perrhenate solution is concentrated, comprising: The volume of the ammonium perrhenate solution is concentrated to 5-20 times the volume of the original ammonium perrhenate solution.

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