Method for separating metallic beryllium from cathode product of fluoride molten salt electrolysis reaction

Abstract

The present invention relates to the field of inorganic materials technology, and in particular to a method for separating metallic beryllium from the cathode product of a fluoride molten salt electrolysis reaction. The method comprises: adding a refluxing agent to the cathode electrolysis product of the fluoride molten salt electrolysis reaction and remelting the product to obtain agglomerated metallic beryllium; the melting density of the refluxing agent is greater than the density of the metallic beryllium, and the melting point of the refluxing agent is less than the melting point of the metallic beryllium. The addition of the refluxing agent during remelting improves the separation of elemental beryllium and entrained molten salt in the cathode electrolysis product during remelting, thereby resolving the problems of the prior art of preparing metallic beryllium by electrolyzing beryllium oxide in fluoride molten salts, such as the difficulty in separating beryllium and molten salt, and the low purity of the finished beryllium product.

Description

Technical Field

[0001] The invention relates to the technical field of beryllium industry, and in particular to a method for separating metallic beryllium from cathode products of a fluoride molten salt electrolysis reaction. Background Art

[0002] Beryllium is an important and indispensable material in atomic energy, rockets, missiles, aviation, and the metallurgical industry. In the existing technology, the preparation of high-purity beryllium mainly adopts molten salt electrolysis. On the one hand, the representative is the beryllium chloride molten salt electrolysis method. For example, Materion in the United States uses the beryllium chloride molten salt electrolysis method to produce 4N high-purity metallic beryllium on a large scale. On the other hand, under the strict blockade of related technologies, this field is also actively developing new molten salt electrolysis methods, such as the beryllium fluoride molten salt electrolysis method. Chinese patent CN114182301A discloses a method for preparing metallic beryllium by electrolyzing beryllium oxide in a fluoride molten salt. The electrolysis can obtain high-purity flake beryllium, but the flake metallic beryllium is dispersed in the fluoride molten salt that is insoluble in water, and the beryllium and the molten salt are difficult to separate. Therefore, the market is in urgent need of a method for separating the cathode electrolysis product metallic beryllium from the fluoride molten salt electrolyte. Summary of the Invention

[0003] In view of the above analysis, the present invention aims to provide a method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction, which solves at least one of the problems in the prior art of preparing flake metallic beryllium by electrolyzing beryllium oxide in fluoride molten salt, which is dispersed in the fluoride molten salt that is insoluble in water, making it difficult to separate beryllium and the molten salt, and the low purity of the finished beryllium product.

[0004] The purpose of the present invention is mainly achieved through the following technical solutions:

[0005] A method for separating metallic beryllium from a cathode product of a fluoride molten salt electrolysis reaction comprises: adding a refluxing agent to the cathode electrolysis product of the fluoride molten salt electrolysis and remelting the resultant to obtain agglomerated metallic beryllium;

[0006] The melting density of the refluxing agent is greater than the density of the metal beryllium, and the melting point of the refluxing agent is less than the melting point of the metal beryllium;

[0007] The method comprises:

[0008] Step 1: Product collection:

[0009] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is a fluoride molten salt containing beryllium cations;

[0010] Step 2: Remelting:

[0011] adding the collected cathode electrolysis products into a remelting agent for remelting to obtain agglomerated metallic beryllium;

[0012] Step 3: Metal Beryllium Solidification

[0013] The agglomerated metallic beryllium is solidified by cooling to obtain solid metallic beryllium element.

[0014] Preferably, the mass proportion of beryllium in the cathode electrolysis product is in the range of 3% to 5%.

[0015] Preferably, the remelting agent in step 2 is one or more of alkali metal chloride, alkaline earth metal chloride, alkali metal fluoride, and alkaline earth metal fluoride.

[0016] Preferably, the refluxing agent in step 2 is one or more of magnesium chloride, calcium chloride, barium chloride, lithium fluoride, potassium fluoride, rubidium fluoride, etc.

[0017] Preferably, the remelting temperature in step 2 is greater than 1285°C, and the boiling point of the remelting agent is greater than or equal to 1400°C.

[0018] Preferably, in step 2, the remelting requires the addition of an additional electrolyte, and the mass ratio of the electrolyte to the cathode electrolysis product and the remelting agent in the remelting system satisfies the following conditions: 1:1 to 7:1 to 10.

[0019] Preferably, in step 3, the temperature for cooling and solidifying the agglomerated metallic beryllium is 800° C. to 1250° C.

[0020] Preferably, the cathode electrolysis product collected in step 1 needs to be crushed and sieved.

[0021] Preferably, the method for separating the cathode electrolysis product metallic beryllium from the fluoride molten salt electrolyte further comprises:

[0022] Step 4, post-processing: remove the remelting agent and other impurities remaining on the surface of the beryllium beads, and obtain beryllium bead powder through water washing and drying.

[0023] A metallic beryllium element is prepared by the above-mentioned method for separating metallic beryllium from cathode products of fluoride molten salt electrolysis reaction, and the purity of the metallic beryllium element is ≥98%.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] (1) The present invention adds a refluxing agent during the remelting of the cathode electrolysis product of beryllium oxide prepared by electrolysis of fluoride molten salt to metal beryllium, thereby improving the separation effect of beryllium element and entrained molten salt in the cathode electrolysis product (flake metal beryllium) during remelting, and solves the problems of difficulty in separating beryllium and molten salt and low purity of finished beryllium products in the prior art of preparing metal beryllium by electrolysis of beryllium oxide by fluoride molten salt;

[0026] (2) The present invention screens beryllium and entrained molten salt in the cathode product at a controlled temperature, so that the beryllium is in a solid state and the molten salt is in a molten state during screening, thereby effectively removing the entrained molten salt.

[0027] Other features and advantages of the present invention will be described in the following description, and some advantages may become apparent from the description or be understood through practice of the present invention. The purposes and other advantages of the present invention may be realized and obtained through the embodiments of the description and the contents particularly pointed out in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 :A process flow chart of the present invention for preparing metallic beryllium by electrolysis of fluoride molten salt;

[0029] Figure 2 : raw material of cathode electrolysis product of fluoride molten salt electrolysis used in Example 1;

[0030] Figure 3 : The solid beryllium metal beryllium elemental substance in the form of beryllium beads prepared in Example 1;

[0031] Figure 4 : raw material of cathode electrolysis product of fluoride molten salt electrolysis used in Example 7;

[0032] Figure 5 : The cathode electrolysis product raw material of the fluoride molten salt electrolysis after screening in Example 7;

[0033] Figure 6 : The solid beryllium metal beryllium bead-like substance prepared in Example 7;

[0034] Figure 7 : The ground beryllium beads prepared in Example 7. DETAILED DESCRIPTION

[0035] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0036] In one aspect, the present invention discloses a method for separating metallic beryllium from a cathode product of a fluoride molten salt electrolysis reaction, comprising: adding a remelting agent to a cathode electrolysis product of the fluoride molten salt electrolysis reaction and remelting the resultant to obtain agglomerated metallic beryllium;

[0037] The melting density of the refluxing agent is greater than the density of metal beryllium, and the melting point of the refluxing agent is less than the melting point of metal beryllium.

[0038] It should be noted that the melting density of the refluxing agent is greater than the melting point of metallic beryllium, thereby ensuring that the liquid metallic beryllium can be suspended on the surface of the refluxing agent and agglomerated; the melting point of the refluxing agent is lower than the melting point of beryllium, thereby ensuring that the agglomerated beryllium balls can be easily removed during the cooling process.

[0039] Compared with the prior art, the present invention adds a refluxing agent during remelting, thereby improving the separation effect of beryllium element and entrained molten salt in the cathode electrolysis product during remelting, and solving the problems of difficulty in separating beryllium and molten salt and low purity of finished beryllium products in the prior art of preparing metallic beryllium by electrolyzing beryllium oxide with fluoride molten salt.

[0040] Specifically, the method for separating metallic beryllium from the cathode product of a fluoride molten salt electrolysis reaction comprises:

[0041] Step 1: Product collection:

[0042] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is a fluoride molten salt containing beryllium cations;

[0043] Step 2: Remelting:

[0044] adding the collected cathode electrolysis products into a remelting agent for remelting to obtain agglomerated metallic beryllium;

[0045] Step 3: Metal Beryllium Solidification

[0046] The agglomerated metallic beryllium is solidified by cooling to obtain solid metallic beryllium element.

[0047] Specifically, the mass ratio of beryllium in the cathode electrolysis product ranges from 3% to 5%.

[0048] Preferably, the cathode electrolysis product collected in step 1 needs to be crushed and sieved.

[0049] Specifically, the mesh number of the sieve is ≤100 meshes, the sieving temperature is 500° C. to 900° C.; the sieve mesh can be tungsten, molybdenum, or nickel mesh.

[0050] It should be noted that the reason for screening in the range of 500℃ to 900℃ is that the melting point of beryllium-containing salts is relatively low, about 450℃, so the screening temperature should be greater than the melting point of beryllium-containing salts and lower than the melting point of metallic beryllium, thereby ensuring the removal of some of the salts; at the same time, the screening temperature should not be too high to prevent the entry of impurity metals.

[0051] Compared with the prior art, the present invention screens beryllium and entrained molten salt in the cathode electrolysis product at a suitable temperature, so that the beryllium is solid and the molten salt is molten during screening. The molten salt passes through the sieve holes, and the solid beryllium remains on the sieve, thereby effectively removing the entrained molten salt.

[0052] Further preferably, the crushing and screening processes are carried out under vacuum or inert gas atmosphere protection.

[0053] Specifically, the vacuum degree is 10-100 Pa, and the inert atmosphere is one or more of argon, nitrogen, and helium.

[0054] Specifically, the electrolyte in step 1 can be one or more of alkali metal fluoride, alkali metal chloride, alkaline earth metal fluoride, alkaline earth metal, and alkaline earth metal chloride.

[0055] Specifically, the remelting agent in step 2 is one or more of alkali metal chloride, alkaline earth metal chloride, alkali metal fluoride, and alkaline earth metal fluoride.

[0056] Preferably, the refluxing agent in step 2 is one or more of magnesium chloride, calcium chloride, barium chloride, lithium fluoride, potassium fluoride, rubidium fluoride, etc.

[0057] Preferably, the remelting temperature in step 2 is greater than 1285°C, and the boiling point of the remelting agent is greater than or equal to 1400°C.

[0058] It should be noted that the melting point of metallic beryllium is 1285°C, so the remelting temperature must be greater than 1285°C; at the same time, the volatilization of the remelting agent must be reduced as much as possible during remelting, and a molten salt with a boiling point above 1400°C should be selected for the remelting process after comprehensive consideration.

[0059] Specifically, the remelting in step 2 requires additional addition of electrolyte, and the mass ratio of the electrolyte, cathode electrolysis product, and remelting agent in the remelting system satisfies the following conditions: 1:1 to 7:1 to 10.

[0060] Preferably, in step 2, the remelting requires the addition of an additional electrolyte, and the mass ratio of the electrolyte to the cathode electrolysis product and the remelting agent in the remelting system satisfies the following conditions: 1:1 to 2:1 to 3.

[0061] Specifically, the additional electrolyte is the same as the original electrolyte of the system.

[0062] Specifically, in step 2, the remelting condition is heating in a stirring device.

[0063] Preferably, in step 3, the temperature for cooling and solidifying the agglomerated metallic beryllium is 800° C. to 1250° C.

[0064] It should be noted that metallic beryllium can solidify in the temperature range of 800°C to 1250°C, while the refluxing agent will not solidify. The difference in melting points can be used to separate metallic beryllium and molten salt.

[0065] Preferably, when the temperature of the metal beryllium drops below 1250° C., the metal beryllium and the molten salt are separated as quickly as possible.

[0066] It should be noted that timely removal of the metal beryllium beads reduces their immersion time in the molten salt to prevent further entry of impurities into the metal beryllium. The metal beryllium beads removed in time have a smoother metal surface and better gloss than those removed after cooling to room temperature.

[0067] Preferably, the method for separating the cathode electrolysis product metallic beryllium further comprises:

[0068] Step 4, post-processing: remove the remelting agent and other impurities remaining on the surface of the solid metal beryllium, and obtain beryllium bead powder through water washing and drying.

[0069] Specifically, methods for removing the refluxing agent and other impurities remaining on the surface of the solid metal beryllium include physical impurity removal and chemical cleaning.

[0070] Specifically, the physical impurity removal can be grinding, and the particle size of the beryllium beads is controlled to be below 1 mm.

[0071] Specifically, the chemical cleaning may be cleaning with dilute nitric acid having a mass concentration of 5% to 10%.

[0072] The invention discloses a method for separating cathode electrolysis product metal beryllium from a fluoride molten salt electrolyte. By adopting the above steps, the yield is ≥97%.

[0073] On the other hand, the present invention discloses high-purity beryllium prepared by the above separation method, wherein the purity of metallic beryllium is ≥98%.

[0074] In order to further illustrate the technical solution of the present invention, the following examples and comparative examples are further provided:

[0075] Example 1

[0076] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0077] Step 1: Product collection:

[0078] Collect the cathode electrolysis products of the electrolysis reaction, such as Figure 2 The scaly beryllium shown has an electrolyte of calcium fluoride molten salt containing beryllium cations; the mass proportion of beryllium in the cathode electrolysis product is 3.2%; the cathode electrolysis product is crushed and sieved, the mesh size is ≤100 mesh, and the sieving temperature is 650°C; the sieving is performed under a vacuum of 10 Pa;

[0079] Step 2: Remelting:

[0080] The cathode electrolysis product that has been crushed and screened is added with additional electrolyte and remelting agent, and then heated to 1400°C in a pit furnace with argon gas. This atmosphere is maintained throughout the remelting process. After the temperature stabilizes, the beryllium liquid is observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. The remelting agent is lithium fluoride. The additional electrolyte is the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product and remelting agent is 1:7:10.

[0081] Step 3: Metal Beryllium Solidification

[0082] The temperature was slowly lowered to solidify the agglomerated metallic beryllium, obtaining solid metallic beryllium. The temperature was further lowered to 1000°C and kept at this temperature for 20 minutes to obtain pure metallic beryllium beads that were stably floating on the molten salt. The beads were then removed using crucible tongs.

[0083] Step 4, post-processing: The diameter of the pure metal beryllium beads floating on the molten salt is about 8mm, such as Figure 3 As shown, the beryllium beads are ground to a particle size of less than 1 mm, and are cleaned with 8% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads. Beryllium bead powder is obtained after water washing and drying.

[0084] The yield of metallic beryllium is calculated to be 97.6%, and the purity of the obtained metallic beryllium is 98.4%.

[0085] Example 2

[0086] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0087] Step 1: Product collection:

[0088] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is sodium fluoride molten salt containing beryllium cations; the mass ratio of beryllium in the cathode electrolysis products is 3.5%; the cathode electrolysis products are crushed and sieved, the mesh number of the sieve is ≤100 mesh, and the sieving temperature is 700° C.; the sieving is performed under an argon atmosphere;

[0089] Step 2: Remelting:

[0090] The screened cathode electrolysis product was remelted by adding additional electrolyte and refluxing agent, and then heated to 1350°C in a pit furnace with argon gas. This atmosphere was maintained throughout the remelting process. After the temperature stabilized, the beryllium liquid was observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. The refluxing agent was a mixture of potassium fluoride and magnesium fluoride (mass ratio 1:1). The additional electrolyte was the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product and refluxing agent was 1:1:4.

[0091] Step 3: Metal Beryllium Solidification

[0092] The agglomerated beryllium metal is solidified by cooling to obtain solid beryllium metal; the temperature is lowered to 950°C and kept at this temperature for 20 minutes, and the solid beryllium metal is removed with a crucible tongs to obtain pure beryllium metal beads stably floating on the molten salt, which are then clamped out;

[0093] Step 4, post-processing: grinding the beryllium beads to a particle size of less than 1 mm, and using 7% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads, and then washing and drying to obtain beryllium bead powder.

[0094] The yield of metallic beryllium is calculated to be 97.3%, and the purity of the obtained metallic beryllium is 98.6%.

[0095] Example 3

[0096] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0097] Step 1: Product collection:

[0098] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is potassium fluoride molten salt containing beryllium cations; the mass proportion of beryllium in the cathode electrolysis products is 3.9%; the cathode electrolysis products are crushed and sieved, the mesh size of the sieve is ≤100 mesh, and the sieving temperature is 750° C.; the sieving is performed under a vacuum environment of 10 Pa;

[0099] Step 2: Remelting:

[0100] The screened cathode electrolysis product was added with additional electrolyte and remelting agent, and then heated to 1350°C in a pit furnace with argon gas. This atmosphere was maintained throughout the remelting process. After the temperature stabilized, the beryllium liquid was observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. The remelting agent was a mixture of magnesium fluoride and rubidium fluoride (mass ratio 1:1). The additional electrolyte was the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product and remelting agent was 1:1:4.

[0101] Step 3: Metal Beryllium Solidification

[0102] The agglomerated beryllium metal was solidified by slowly cooling down to obtain solid beryllium metal. The temperature was further lowered to 900°C and kept at this temperature for 20 minutes. The solid beryllium metal was removed with crucible tongs to obtain pure beryllium metal beads floating stably on the molten salt. The solid beryllium metal beads were then removed by clipping.

[0103] Step 4, post-processing: grinding the beryllium beads to a particle size of less than 1 mm, and using 10% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads, and then washing and drying to obtain beryllium bead powder.

[0104] The yield of metallic beryllium is calculated to be 97%, and the purity of the obtained metallic beryllium is 98.2%.

[0105] Example 4

[0106] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0107] Step 1: Product collection:

[0108] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is a lithium fluoride molten salt containing beryllium cations; the mass ratio of beryllium in the cathode electrolysis products is 4.5%; the cathode electrolysis products are crushed and sieved, the mesh size of the sieve is ≤100 mesh, and the sieving temperature is 800° C.; the sieving is performed under an argon atmosphere;

[0109] Step 2: Remelting:

[0110] The screened cathode electrolysis product was added to a remelting agent for remelting, and then heated to 1450°C in a pit furnace with argon gas. This atmosphere was maintained throughout the remelting process. After the temperature stabilized, the beryllium liquid was observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. The remelting agent was magnesium fluoride. The additional electrolyte was the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product to remelting agent was 1:3:5.

[0111] Step 3: Metal Beryllium Solidification

[0112] The temperature was slowly lowered to solidify the agglomerated beryllium metal, and solid beryllium metal was obtained. The temperature was further lowered to 1250°C and kept at this temperature for 15 minutes. The solid beryllium metal was removed with a crucible tongs to obtain pure beryllium metal beads that were stably floating on the molten salt and then clamped out.

[0113] Step 4, post-processing: grinding the beryllium beads to a particle size of less than 1 mm, and using 6% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads, and then washing and drying to obtain beryllium bead powder.

[0114] The yield of metallic beryllium is calculated to be 98.1%, and the purity of the obtained metallic beryllium is 98.3%.

[0115] Example 5

[0116] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0117] Step 1: Product collection:

[0118] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is a molten salt containing lithium fluoride and sodium fluoride in a mass ratio of 1:1 containing beryllium cations; the mass ratio of beryllium in the cathode electrolysis products is 3.7%; the cathode electrolysis products are crushed and sieved, the mesh size of the sieve is ≤100 mesh, and the sieving temperature is 850° C.; the sieving is performed under a vacuum of 50 Pa;

[0119] Step 2: Remelting:

[0120] The screened cathode electrolysis product was added to a remelting agent for remelting, and then heated to 1450°C in a pit furnace with argon gas. This atmosphere was maintained throughout the remelting process. After the temperature stabilized, the beryllium liquid was observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. The remelting agent was barium chloride. The additional electrolyte was the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product to remelting agent was 1:1:3.

[0121] Step 3: Metal Beryllium Solidification

[0122] The agglomerated beryllium metal was solidified by slowly cooling down to obtain solid beryllium metal. The temperature was further lowered to 900°C and kept at this temperature for 20 minutes. The solid beryllium metal was removed with crucible tongs to obtain pure beryllium metal beads floating stably on the molten salt. The solid beryllium metal beads were then removed by clipping.

[0123] Step 4, post-processing: grinding the beryllium beads to a particle size of less than 1 mm, and using 5% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads, and then washing and drying to obtain beryllium bead powder.

[0124] The yield of metallic beryllium is calculated to be 99%, and the purity of the obtained metallic beryllium is 99.1%.

[0125] Example 6

[0126] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0127] Step 1: Product collection:

[0128] collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is calcium fluoride molten salt containing beryllium cations; the mass proportion of beryllium in the cathode electrolysis products is 4.3%; the cathode electrolysis products are crushed and sieved, the mesh size of the sieve is ≤100 mesh, and the sieving temperature is 900° C.; the sieving is performed under a helium atmosphere;

[0129] Step 2: Remelting:

[0130] The screened cathode electrolysis product was added to a remelting agent for remelting, and then heated to 1400°C in a pit furnace with argon gas. This atmosphere was maintained throughout the remelting process. After the temperature stabilized, the beryllium liquid was observed for agglomeration every 10 minutes to obtain agglomerated metallic beryllium. Calcium chloride was used as the remelting agent. The additional electrolyte was the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product to remelting agent was 1:3:7.

[0131] Step 3: Metal Beryllium Solidification

[0132] The temperature was slowly lowered to solidify the agglomerated metallic beryllium, and solid metallic beryllium was obtained. The temperature was further lowered to 1050°C and kept at this temperature for 20 minutes. The solid beryllium was removed with a crucible tongs to obtain pure metallic beryllium beads that were stably floating on the molten salt and then clipped out.

[0133] Step 4, post-processing: grinding the beryllium beads to a particle size of less than 1 mm, and using 8% dilute nitric acid to remove the residual refluxing agent and other impurities on the surface of the beryllium beads, and then washing and drying to obtain beryllium bead powder.

[0134] The yield of metallic beryllium is calculated to be 98.5%, and the purity of the obtained metallic beryllium is 98.8%.

[0135] Example 7

[0136] This embodiment discloses a method for separating metallic beryllium, a cathode electrolysis product, from a fluoride molten salt electrolyte, comprising the following steps:

[0137] Step 1: Product collection:

[0138] Collect the cathode electrolysis products of the electrolysis reaction (scattered in the molten salt and adhered to the cathode rod), such as Figure 3 The scale-like beryllium shown in the figure is an electrolyte containing lithium fluoride-beryllium fluoride molten salt containing beryllium cations; the mass ratio of beryllium in the cathode electrolysis product is 3.48%; the cathode electrolysis product is crushed and sieved as shown in the figure. Figure 4 As shown, the mesh number of the sieve is ≤100 mesh, the sieving temperature is 750°C, and the sieving is carried out under a vacuum degree of 10Pa.

[0139] Step 2: Remelting:

[0140] The cathode electrolysis product that has been crushed and screened is added with additional electrolyte and remelting agent, then heated to 1350°C in a pit furnace with argon gas. This atmosphere is maintained throughout the remelting process. After the temperature stabilizes, it is kept warm for 60 minutes. The agglomeration state of the beryllium liquid is observed every 10 minutes to obtain agglomerated metallic beryllium. The remelting agent is lithium fluoride. The additional electrolyte is the same as the original electrolyte in the system, and the mass ratio of electrolyte to cathode electrolysis product and remelting agent is 1:7:10.

[0141] Step 3: Metal Beryllium Solidification

[0142] Slowly cool the agglomerated beryllium to solidify, and obtain solid beryllium. Continue to cool to 1000℃ and keep warm for 20 minutes to obtain pure beryllium beads floating stably on the molten salt (such as Figure 6 ), then remove it with tweezers;

[0143] Step 4, post-processing: The diameter of the pure metal beryllium beads floating on the molten salt is about 8mm (such as Figure 6As shown), there are also a large number of very small beryllium beads, which are ground to a particle size of less than 1 mm (as shown Figure 7 As shown), 8% dilute nitric acid is used to remove the residual refluxing agent and other impurities on the surface of the beryllium bead, and the beryllium bead powder is obtained after water washing and drying.

[0144] The yield of metallic beryllium is calculated to be 97.8%, and the purity of the obtained metallic beryllium is 99.1%.

[0145] Comparative Example 1

[0146] In this comparative example, beryllium was prepared in the same manner as in Example 3, except that no remelting agent was added during remelting in step 2. The remaining steps and conditions were the same as in Example 3.

[0147] The yield of metallic beryllium is calculated to be 91%, and the purity of the metallic beryllium is 93%.

[0148] Comparative Example 2

[0149] In this comparative example, beryllium was prepared by the same method as in Example 3, except that the temperature for cooling and solidifying the agglomerated metallic beryllium in step 3 was 700°C.

[0150] The yield of metallic beryllium is calculated to be 97%, and the purity of the obtained metallic beryllium is 90%.

[0151] Comparative Example 3

[0152] This comparative example adopts the method disclosed in CN114182301A for preparing metallic beryllium by electrolyzing beryllium oxide in a fluoride molten salt. Under the same method, the cathode flaky electrolysis product is dispersed in the fluoride molten salt and is difficult to separate.

[0153] It should be noted that the yield of metallic beryllium in the present invention refers to the mass ratio of the beryllium element in the metal product after treatment to that in the metal product before treatment.

[0154] The purity of metallic beryllium is measured using icp-oes equipment.

[0155] The results show:

[0156] The yield of metallic beryllium prepared in Examples 1 to 6 of the present invention is greater than 97%, and the purity of the metallic beryllium prepared is greater than 98%;

[0157] Comparing Example 7 with Comparative Example 1, it can be seen that in Comparative Example 1, no remelting agent was added, and the separation effect of beryllium and molten salt during remelting was poor, and the yield of metallic beryllium and the purity of metallic beryllium were significantly reduced (reduced to 91% and 93%, respectively);

[0158] By comparing Example 1 and Comparative Example 2, it can be seen that the temperature for cooling and solidifying the agglomerated metallic beryllium in step 3 in Comparative Example 2 is low, the separation effect of the beryllium element and the molten salt during remelting is poor, and the purity of the metallic beryllium element is significantly reduced (from 98.4% to 90%).

[0159] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A method for separating metallic beryllium from the cathode product of a fluoride molten salt electrolysis reaction, characterized in that: The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction comprises: adding a remelting agent to the cathode electrolysis product of the fluoride molten salt electrolysis and remelting the resultant to obtain agglomerated metallic beryllium; The melting density of the refluxing agent is greater than the density of the metal beryllium, and the melting point of the refluxing agent is less than the melting point of the metal beryllium; The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction comprises: Step 1: Product collection: collecting cathode electrolysis products of the electrolysis reaction, wherein the electrolyte is a fluoride molten salt containing beryllium cations; Step 2: Remelting: The collected cathode electrolysis product is added to a remelting agent for remelting to obtain agglomerated metallic beryllium; the remelting in step 2 requires additional addition of electrolyte, and the mass ratio of electrolyte to cathode electrolysis product and remelting agent in the remelting system satisfies the following requirements: 1:1 to 7:1 to 10; Step 3: Solidification of metal beryllium: The temperature of the agglomerated metal beryllium is lowered to solidify, thereby obtaining solid metal beryllium. In step 3, the temperature of the agglomerated metal beryllium is lowered to solidify at 800° C. to 1250° C.

2. The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction according to claim 1, characterized in that: The mass ratio of beryllium in the cathode electrolysis product is in the range of 3% to 5%.

3. The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction according to claim 1, characterized in that: In step 2, the remelting agent is one or more of alkali metal chloride, alkaline earth metal chloride, alkali metal fluoride, and alkaline earth metal fluoride.

4. The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction according to claim 3, characterized in that: In step 2, the refluxing agent is one or more of magnesium chloride, calcium chloride, barium chloride, lithium fluoride, potassium fluoride, rubidium fluoride, etc.

5. The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction according to claim 1, characterized in that: In step 2, the remelting temperature is greater than 1285° C., and the boiling point of the remelting agent is greater than or equal to 1400° C.

6. The method for separating metallic beryllium from the cathode product of a fluoride molten salt electrolysis reaction according to claim 1, characterized in that: The cathode electrolysis products collected in step 1 need to be crushed and sieved.

7. The method for separating metallic beryllium from the cathode product of a fluoride molten salt electrolysis reaction according to any one of claims 1 to 6, characterized in that: The method for separating metallic beryllium from the cathode product of the fluoride molten salt electrolysis reaction further comprises: Step 4, post-processing: remove the remelting agent and other impurities remaining on the surface of the beryllium beads, and obtain beryllium bead powder through water washing and drying.

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