Preparation method of anhydrous beryllium chloride and anhydrous beryllium chloride

Abstract

The present application relates to the technical field of inorganic material, and more particularly to a preparation method of anhydrous beryllium chloride and the anhydrous beryllium chloride, which comprises the following steps: preparing the anhydrous beryllium chloride by chlorination reaction of the natural state metal beryllium after surface treatment by hydrogen and chlorine, greatly shortening the process flow and simplifying the operation; meanwhile, the new impurities are avoided, the defects of poor reactivity of beryllium and low yield of beryllium chloride are improved, the purity and yield of the anhydrous beryllium chloride are improved, and the water content is reduced; the yield of the anhydrous beryllium chloride after chlorination can reach 58.2% to 85.3%, and the content of the beryllium chloride can reach 80.3% to 94.6%; meanwhile, the chlorides generated by the reaction of the metal impurities and the chlorine are purified by steps according to the different boiling points, the purity of the anhydrous beryllium chloride is further improved, and the rare metal tantalum in the beryllium ore is recovered; the content of the beryllium chloride after purification is greater than or equal to 99.6%, and the water content of the anhydrous beryllium chloride is less than or equal to 0.2%.

Description

Technical Field

[0001] This invention relates to the field of beryllium industry technology, and in particular to a method for preparing anhydrous beryllium chloride and anhydrous beryllium chloride. Background Technology

[0002] Beryllium chloride is a colorless solid with a melting point of approximately 399°C. It is highly hygroscopic and readily soluble in many polar solvents, making it an important precursor for the electrolytic preparation of high-purity metallic beryllium, commonly used in molten salt electrolysis. However, existing techniques (such as the hydrochloric acid-beryllium oxide method) produce beryllium chloride containing water of crystallization. This presents several challenges: firstly, beryllium chloride containing water of crystallization is unsuitable for use as a raw material in molten salt electrolysis for metallic beryllium; secondly, beryllium chloride is prone to sublimation, making it difficult to remove the water of crystallization through drying. Furthermore, during heating, some beryllium chloride containing water of crystallization inevitably hydrolyzes to form the more stable beryllium oxide (melting point approximately 2350°C), which cannot be used in molten salt electrolysis for high-purity metallic beryllium, resulting in significant waste of beryllium chloride. Therefore, there is an urgent market need for an efficient method to prepare high-purity anhydrous beryllium chloride. Summary of the Invention

[0003] Based on the above analysis, the present invention aims to provide a method for preparing anhydrous beryllium chloride and anhydrous beryllium chloride, thereby solving at least one of the problems of low purity and difficulty in purification in the preparation of anhydrous beryllium chloride in the prior art.

[0004] The objective of this invention is mainly achieved through the following technical solutions:

[0005] An anhydrous beryllium chloride preparation method involves surface-treating naturally occurring metallic beryllium with hydrogen and then reacting it with chlorine to prepare anhydrous beryllium chloride.

[0006] Preferably, the method for preparing the anhydrous beryllium chloride includes the following steps:

[0007] Step 1: Place beryllium metal in its natural state inside a sealed reactor and introduce inert gas to create an inert atmosphere;

[0008] Step 2: Hydrogenation treatment of naturally occurring metallic beryllium by introducing hydrogen gas into a sealed reactor;

[0009] Step 3: Inert gas is introduced into the sealed reactor again to form an inert atmosphere;

[0010] Step 4: Introduce chlorine gas into a closed reactor and obtain beryllium chloride through a chlorination reaction.

[0011] Preferably, in step 2, the ratio of the mass of naturally occurring beryllium to the flow rate of hydrogen gas is 1 g: (10-80) ccm, and / or the hydrogenation reaction temperature is 200°C to 800°C.

[0012] Preferably, in step 4, the ratio of the mass of naturally occurring beryllium to the flow rate of chlorine gas is 1 g:(100~200)ccm, the chlorination reaction temperature in step 4 is 500℃~1200℃, and / or, the chlorination reaction heating rate in step 4 is ≤15℃ / min.

[0013] Preferably, in step 1, the particle size of the naturally occurring beryllium metal is 15 μm to 250 μm, and / or the purity of the naturally occurring beryllium metal is ≥98%.

[0014] An anhydrous beryllium chloride, prepared by the above method, has a beryllium chloride purity ≥99.6% and a water content ≤0.2%.

[0015] An active beryllium element is obtained by hydrogenating naturally occurring metallic beryllium to remove surface beryllium oxide using the method described above. The active beryllium element can react directly with water, chlorine, or dilute acid.

[0016] A method for preparing active beryllium, comprising: using hydrogen to treat the surface of naturally occurring metallic beryllium to obtain active beryllium.

[0017] Preferably, the particle size of the naturally occurring beryllium metal is 15μm to 250μm, and / or the purity of the naturally occurring beryllium metal is ≥98%.

[0018] Preferably, the ratio of the mass of naturally occurring beryllium to the flow rate of hydrogen is 1 g:(10-80)ccm, and / or the temperature for surface treatment using hydrogen is 200°C to 800°C.

[0019] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0020] (1) This invention uses hydrogen to hydrogenate the beryllium oxide on the surface of metallic beryllium, and then reacts the hydrogenated metallic beryllium with chlorine. On the one hand, this greatly shortens the process flow and simplifies the operation; on the other hand, it improves the defects of poor reactivity of elemental beryllium with chlorine and low yield of beryllium chloride. The yield of anhydrous beryllium chloride after chlorination can reach 58.2% to 85.3%, and the beryllium chloride content can reach 80.3% to 94.6%.

[0021] (2) The present invention uses hydrogenated beryllium metal to react directly with chlorine gas, which makes it easy to separate the raw materials and products. At the same time, it avoids the introduction of new impurities and avoids the defects of water and other impurities that are difficult to remove in the prior art. It improves the purity and yield of anhydrous beryllium chloride and reduces the water content.

[0022] (3) In this invention, the prepared beryllium chloride is sublimated and purified at different temperature stages. The stepwise purification is carried out by utilizing the different boiling points of the chlorides generated by the reaction of metal impurities and chlorine gas. This achieves the separation of beryllium chloride from impurities such as silicon, aluminum and iron, which are present in small amounts. This improves the purity of anhydrous beryllium chloride and recovers the rare metal tantalum from beryllium ore. After purification, the beryllium chloride content is ≥99.6% and the water content of anhydrous beryllium chloride is ≤0.2%;

[0023] (4) This invention uses high density (0.48-0.72 g / cm³) 3 Using beryllium metal powder as raw material, compared to the low bulk density of beryllium oxide (0.18-0.27 g / cm³), 3 It has advantages such as being less likely to generate dust and being easier to operate in a vacuum, thus reducing the risk of beryllium poisoning.

[0024] Other features and advantages of the invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained from what is particularly pointed out in the embodiments described herein. Detailed Implementation

[0025] This invention discloses a method for preparing anhydrous beryllium chloride, comprising:

[0026] Anhydrous beryllium chloride is prepared by reacting naturally occurring beryllium metal treated with hydrogen with chlorine gas.

[0027] It should be noted that beryllium is covered with a thin layer of oxide during storage and transportation, which prevents it from being further oxidized, chlorinated, or corroded by air and acid. Removing the surface beryllium oxide helps the reactive beryllium to participate in the reaction.

[0028] It should be noted that beryllium oxide on the surface of elemental beryllium is difficult to remove by mechanical polishing or chemical etching. This is because: the oxide layer on the surface of elemental beryllium is nanometer-thick and cannot be removed by ordinary mechanical processing without losing elemental beryllium; at the same time, both beryllium oxide and elemental beryllium are obvious amphoteric substances—they can react with both acids and bases, and beryllium oxide exhibits stronger stability than elemental beryllium and is less susceptible to corrosion by acids, bases and other chemical agents. This makes the beryllium oxide layer difficult to remove by chemical methods and prevents elemental beryllium from reacting further with the external environment. As a result, elemental beryllium with a rich surface oxide layer exhibits strong chemical inertness.

[0029] It should be noted that beryllium, being a metal more reactive than hydrogen, has oxides that are difficult to react with hydrogen to form elemental beryllium. The applicant's research found that after hydrogenation treatment of the oxide layer on the surface of metallic beryllium in a hydrogen environment, the beryllium oxide layer is destroyed, and the internal elemental beryllium can further react with chlorine to prepare beryllium chloride. Although the underlying mechanism is not yet clear, the yield of anhydrous beryllium chloride prepared by the reaction of hydrogenated metallic beryllium with chlorine is increased from 12.4% to over 58% compared to the untreated sample.

[0030] Compared with the prior art, the present invention uses hydrogen as the hydrogenation gas, which overcomes the defect that beryllium oxide naturally forms on the outer surface of elemental beryllium, making it unable to react with chlorine. Compared with the prior art scheme of preparing beryllium chloride by reacting beryllium or beryllium oxide with hydrogen chloride and its aqueous solution, the present invention overcomes the defects of high water content and difficulty in purification of the product of the prior art scheme, and can prepare high-purity anhydrous beryllium chloride.

[0031] Compared with existing technologies, this invention uses hydrogen as the hydrogenation treatment gas to remove the nano-beryllium oxide layer on the surface of metallic beryllium. Compared with the traditional "beryllium oxide + carbon + chlorine" one-step preparation of beryllium chloride system, this invention avoids the introduction of carbon impurities and side reactions while removing surface beryllium oxide, thus improving the purity of the prepared anhydrous beryllium chloride.

[0032] Specifically, the method for preparing anhydrous beryllium chloride includes the following steps:

[0033] Step 1: Place beryllium metal in its natural state inside a sealed reactor and introduce inert gas to create an inert atmosphere;

[0034] Step 2: Hydrogenation treatment of naturally occurring metallic beryllium by introducing hydrogen gas into a sealed reactor;

[0035] Step 3: Inert gas is introduced into the sealed reactor again to form an inert atmosphere;

[0036] Step 4: Introduce chlorine gas into a closed reactor and obtain beryllium chloride through a chlorination reaction.

[0037] Compared with the prior art, the present invention destroys the inert beryllium oxide layer by hydrogenating the surface of naturally occurring beryllium metal, allowing the beryllium metal to react with chlorine gas, which greatly shortens the process flow, simplifies the operation, and results in a high yield of anhydrous beryllium chloride after the chlorination reaction.

[0038] Specifically, in step 1, the naturally occurring metallic beryllium is preferably in powder form with a particle size of 15μm to 250μm and a purity of ≥98%.

[0039] Understandably, if the beryllium metal particles are too large, the reaction will be incomplete, resulting in a decrease in the purity and yield of anhydrous beryllium chloride; if the beryllium metal particles are too small, the reaction will be too vigorous, which is not conducive to controlling the reaction process.

[0040] Specifically, step 1 also includes multiple vacuuming operations to remove air and introducing inert gas to further reduce the oxygen content in the sealed reactor.

[0041] Specifically, the inert gas is introduced for 10 to 40 minutes.

[0042] Specifically, the vacuum level for each evacuation is controlled between 0.01 MPa and 0.3 MPa.

[0043] Specifically, in step 2, the ratio of the mass of naturally occurring beryllium added to the closed reactor to the flow rate of hydrogen is 1g:(10-80)ccm, for example, 1g:10ccm, 1g:12ccm, 1g:15ccm, 1g:20ccm, 1g:25ccm, 1g:30ccm, 1g:35ccm, 1g:40ccm, 1g:45ccm, 1g:50ccm, 1g:55ccm, 1g:60ccm, 1g:65ccm, 1g:70ccm, 1g:75ccm, 1g:80ccm.

[0044] It can be understood that the relative flow rate of hydrogen relative to the mass of added beryllium is kinetically related to the partial pressure of hydrogen. Selecting the above relative flow rate can adjust the reaction rate and the oxide film removal effect: a larger relative flow rate results in a larger relative reaction rate and poorer uniformity of the surface beryllium oxide reaction; a smaller relative flow rate results in a smaller relative reaction rate, more uniform and complete surface beryllium oxide reaction, and improved anhydrous beryllium chloride yield.

[0045] Preferably, the optimal ratio of the mass of naturally occurring beryllium added in step 2 to the flow rate of hydrogen gas is 1g: 20-60ccm.

[0046] Specifically, in step 2, the hydrogen gas introduction time is 30 to 150 minutes, for example, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, 120 minutes, 125 minutes, 130 minutes, 135 minutes, 140 minutes, 145 minutes, and 150 minutes.

[0047] It can be understood that the time for hydrogen to be introduced is the reaction time for hydrogen deoxygenation. If the time is too short, the reaction will be incomplete and some oxide film will not be removed; if the time is too long, it may waste hydrogen and further reduce efficiency.

[0048] Specifically, in step 2, the hydrogenation reaction temperature is controlled between 200℃ and 800℃, for example, 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, and 800℃.

[0049] It is understandable that the above hydrogenation reaction temperatures were selected because: below 200℃, the hydrogenation reaction is basically impossible; above 800℃, the hydrogenation reaction is too vigorous, which not only further increases energy consumption, but also intensifies the corrosion of the inert layer on the inner surface of the reactor by hydrogen, reducing the reactor's lifespan; and at high temperatures, the hydrogen's ability to permeate the reactor's inner material is too high, which will also affect the reactor's sealing and safety.

[0050] Preferably, the optimal range of hydrogenation reaction temperature in step 2 is 400℃~700℃.

[0051] Specifically, the inert gas in steps 1 and 3 is any one of helium (He), neon (Ne), or argon (Ar).

[0052] Specifically, step 3 also includes multiple vacuuming operations to remove empty hydrogen gas and introducing inert gas. The advantages of this operation are: on the one hand, it can further reduce the oxygen content in the closed reactor and prevent beryllium oxide from being generated again on the surface of beryllium; on the other hand, it can use inert gas to remove hydrogen gas and avoid hydrogen residue, which will react with chlorine gas during the chlorination reaction.

[0053] Specifically, the inert gas is introduced for 10 to 40 minutes.

[0054] Specifically, the vacuum level for each evacuation is controlled between 0.01 MPa and 0.3 MPa.

[0055] Specifically, in step 4, the ratio of the mass of naturally occurring beryllium to the flow rate of chlorine gas is 1g:(100~200)ccm, for example, 1g:100ccm, 1g:110ccm, 1g:120ccm, 1g:130ccm, 1g:140ccm, 1g:150ccm, 1g:160ccm, 1g:170ccm, 1g:180ccm, 1g:190ccm, 1g:200ccm.

[0056] It can be understood that the relative flow rate of chlorine gas relative to the mass of added beryllium is reflected kinetically as the partial pressure of chlorine gas. Selecting the above relative flow rate can adjust the reaction rate and reaction uniformity: a larger relative flow rate results in a larger relative reaction rate and poorer uniformity of the reaction between surface beryllium and chlorine gas; a smaller relative flow rate results in a smaller reaction rate, better uniformity of the reaction between surface beryllium and chlorine gas, a reduction in unreacted beryllium in some areas, and a higher beryllium chloride yield.

[0057] Compared with existing technologies, this invention uses beryllium to react directly with chlorine, which avoids the formation of a second product compared with the reaction of beryllium with hydrochloric acid. It does not produce flammable and explosive hydrogen gas, and at the same time avoids the introduction of water, which is beneficial for obtaining anhydrous beryllium chloride and reduces the loss of beryllium chloride during drying. The product beryllium chloride and the raw material gas are also easier to separate.

[0058] Specifically, in step 4, the chlorine gas is introduced for a period of 3 to 16 hours, for example, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, 10.5h, 11h, 11.5h, 12h, 12.5h, 13h, 13.5h, 14h, 14.5h, 15h, 15.5h, and 16h.

[0059] It is understandable that the above chlorine gas introduction time was selected because: if the chlorine gas introduction time is too short, the ratio of the added beryllium mass to the chlorine gas flow rate is within 1g:(100~200)ccm, which cannot meet the chlorine gas supply requirements for the reaction with beryllium; if the chlorine gas introduction time is too long, it will cause unnecessary waste in the post-processing of unreacted chlorine gas.

[0060] Specifically, in step 3, the chlorine gas introduction time and the chlorine gas flow rate should meet the ratio of the total amount of chlorine gas introduced to the total amount of chlorine gas theoretically required for complete reaction with naturally occurring beryllium metal, which is (3.6~39):1.

[0061] It can be understood that the total amount of chlorine introduced should be excessive, the flow rate of chlorine introduced should be small, and the chlorine introduction time should be appropriately extended to ensure that the ratio of the total amount of chlorine introduced to the theoretically required total amount of chlorine varies between (3.6 and 39):1.

[0062] Specifically, in step 4, the chlorination reaction temperature is controlled between 500℃ and 1200℃, for example, 500℃, 520℃, 550℃, 580℃, 600℃, 620℃, 650℃, 680℃, 700℃, 720℃, 750℃, 780℃, 800℃, 820℃, 850℃, 880℃, 900℃, 920℃, 950℃, 980℃, 1000℃, 1020℃, 1050℃, 1080℃, 1100℃, 1120℃, 1150℃, 1180℃, and 1200℃.

[0063] It is understandable that the above chlorination reaction temperature was selected because: below 500℃, the chlorination reaction is basically impossible; above 1200℃, the chlorination reaction is too vigorous. On the one hand, this increases the energy consumption of the subsequent beryllium chloride separation stage (such as condensation and collection of beryllium chloride). On the other hand, it is difficult to avoid the presence of trace amounts of water vapor in the reactor. Under the combined action of water vapor and chlorine, the corrosion of the inert layer on the surface of the reactor cavity is aggravated at high temperatures, reducing the life of the reactor.

[0064] Preferably, the optimal temperature range for the chlorination reaction in step 4 is 700℃ to 1000℃. Within this temperature range, the corrosion of the reactor's inner surface by chlorine gas and the introduction of impurities such as iron into the reactor can be reduced (e.g., iron impurities are introduced into steel reactors due to corrosion by chlorine gas), which helps maintain a high yield and purity of anhydrous beryllium chloride.

[0065] Specifically, in step 4, the chlorination reaction heating rate is ≤15℃ / min, for example, 1℃ / min, 2℃ / min, 3℃ / min, 4℃ / min, 5℃ / min, 6℃ / min, 7℃ / min, 8℃ / min, 9℃ / min, 10℃ / min, 11℃ / min, 12℃ / min, 13℃ / min, 14℃ / min, 15℃ / min.

[0066] It is understandable that the above heating rate was chosen because a rate higher than 15°C / min would cause beryllium to burn violently in chlorine, which would be detrimental to controlling the reaction rate.

[0067] Preferably, the heating rate of the chlorination reaction in step 4 is selected as 5℃ / min to 10℃ / min.

[0068] It is understandable that the reason for selecting a heating rate of 5℃ / min to 10℃ / min is that the heating rate is related to the particle size of metallic beryllium. When the particle size of metallic beryllium is 15μm to 250μm, a heating rate of 5℃ / min to 10℃ / min helps the metallic beryllium to be chlorinated gently and gradually from the outside to the inside.

[0069] Specifically, in step 4, beryllium chloride is discharged from the reactor in gaseous state and unreacted chlorine gas. Step 4 also includes: condensing beryllium chloride and unreacted chlorine gas to separate solid beryllium chloride.

[0070] Specifically, the exhaust gas, after condensation treatment, is passed into an alkaline solution for absorption.

[0071] Preferably, absorption is achieved by passing the solution through two or more alkaline solutions.

[0072] Preferably, a potassium hydroxide solution with a concentration of 1 mol / L to 2 mol / L is selected as the alkaline solution, which has a better effect on chlorine recovery.

[0073] Preferably, step 4 further includes a sublimation purification operation of beryllium chloride.

[0074] It should be noted that crude beryllium mainly originates from beryl, and in addition to common impurities such as aluminum, iron, silicon, magnesium, and calcium, it also contains the rare metal tantalum. During the preparation of beryllium chloride, tantalum generates easily sublimable chlorides.

[0075] Specifically, the sublimation purification of beryllium chloride includes three stages: low-temperature sublimation, medium-temperature sublimation, and high-temperature sublimation, including:

[0076] Low-temperature sublimation stage: The beryllium chloride prepared in step 4 is heated at the first temperature to complete the sublimation of aluminum and iron impurities and the separation of beryllium chloride;

[0077] Intermediate-temperature sublimation stage: The crude beryllium chloride, which has completed low-temperature and intermediate-temperature sublimation, is heated at a second temperature to complete the sublimation of tantalum impurities and the separation of beryllium chloride. The rare metal tantalum is then cooled and recovered.

[0078] High-temperature sublimation stage: The crude beryllium chloride, which has completed low-temperature and medium-temperature sublimation, is heated at a third temperature to complete the sublimation of beryllium chloride and the separation of beryllium chloride from magnesium, calcium, and silicon impurities.

[0079] Specifically, the low-temperature sublimation stage is sublimation at ambient pressure, with a temperature of 180℃~200℃.

[0080] Specifically, the intermediate-temperature sublimation stage is sublimation at ambient pressure, with a temperature of 240℃~260℃.

[0081] Specifically, the high-temperature sublimation stage is depressurization sublimation, with a temperature of 350℃~430℃ and a pressure ≤2×10. -2 torr.

[0082] During implementation, aluminum and iron impurities exist in the form of chlorides. The sublimation temperature of aluminum and iron chlorides is lower than that of beryllium chloride, so they can be sublimated and separated at a lower temperature.

[0083] Tantalum chloride has a higher sublimation temperature than aluminum and iron chlorides, but lower than beryllium chloride. It can be sublimated and separated at a temperature lower than that of beryllium chloride, thus enabling the recovery of trace amounts of tantalum from beryllium chloride.

[0084] Magnesium, calcium, and silicon impurity compounds have boiling points or sublimation temperatures much higher than those of beryllium chloride. At temperatures above the sublimation temperature of beryllium chloride, beryllium chloride sublimates and separates from the impurities.

[0085] Understandably, sublimation is related to the relative magnitudes of the solid vapor pressure and the external pressure; reducing the external pressure can lower the sublimation temperature and increase the sublimation rate.

[0086] Compared with existing technologies, this invention achieves further separation of iron, aluminum and tantalum coexisting with beryllium in beryllium raw materials through multiple sublimation separations at multiple temperature stages, and realizes the recovery and utilization of rare metal tantalum.

[0087] This invention discloses a method for preparing active elemental beryllium, which involves removing surface beryllium oxide from naturally occurring metallic beryllium through hydrogenation treatment to obtain active elemental beryllium, comprising the following steps:

[0088] Step 1: Place beryllium metal in its natural state inside a sealed reactor and introduce inert gas to create an inert atmosphere;

[0089] Step 2: Hydrogenation treatment of naturally occurring beryllium metal is carried out by introducing hydrogen gas into a closed reactor.

[0090] Specifically, in step 1, the metallic beryllium is in powder form with a particle size of 15μm to 250μm and a purity of ≥98%.

[0091] Understandably, if the beryllium metal particles are too large, the reaction will be incomplete, resulting in a decrease in the purity and yield of anhydrous beryllium chloride; if the beryllium metal particles are too small, the reaction will be too vigorous, which is not conducive to controlling the reaction process.

[0092] Specifically, step 1 also includes multiple vacuuming operations to remove air and introducing inert gas to further reduce the oxygen content in the sealed reactor.

[0093] Specifically, the inert gas is introduced for 10 to 40 minutes.

[0094] Specifically, the vacuum level for each evacuation is controlled between 0.01 MPa and 0.3 MPa.

[0095] Specifically, in step 2, the ratio of the mass of naturally occurring beryllium added to the closed reactor to the flow rate of hydrogen is 1g:(10-80)ccm, for example, 1g:10ccm, 1g:12ccm, 1g:15ccm, 1g:20ccm, 1g:25ccm, 1g:30ccm, 1g:35ccm, 1g:40ccm, 1g:45ccm, 1g:50ccm, 1g:55ccm, 1g:60ccm, 1g:65ccm, 1g:70ccm, 1g:75ccm, 1g:80ccm.

[0096] It can be understood that the relative flow rate of hydrogen relative to the mass of added beryllium reacts kinetically, which is the partial pressure of hydrogen. Selecting the above relative flow rate can adjust the reaction rate and the oxide film removal effect: a larger relative flow rate results in a larger relative reaction rate and poorer uniformity of the surface beryllium oxide reaction; a smaller relative flow rate results in a smaller relative reaction rate and more uniform surface beryllium oxide reaction.

[0097] Preferably, the optimal range for the ratio of the mass of beryllium added in the hydrogenation reaction to the flow rate of hydrogen gas in step 2 is 1g: 20ccm to 60ccm.

[0098] Specifically, in step 2, the hydrogen gas introduction time is 30 min to 150 min, for example, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, 65 min, 70 min, 75 min, 80 min, 85 min, 90 min, 95 min, 100 min, 105 min, 110 min, 115 min, 120 min, 125 min, 130 min, 135 min, 140 min, 145 min, and 150 min.

[0099] It can be understood that the time for hydrogen to be introduced is the reaction time for hydrogen deoxygenation. If the time is too short, the reaction will be incomplete and some oxide film will not be removed; if the time is too long, it may waste hydrogen and further reduce efficiency.

[0100] Specifically, in step 2, the hydrogenation reaction temperature is controlled between 200℃ and 800℃, for example, 200℃, 250℃, 300℃, 350℃, 400℃, 450℃, 500℃, 550℃, 600℃, 650℃, 700℃, 750℃, and 800℃.

[0101] It is understandable that the above hydrogenation reaction temperature was selected because: below 200℃, the hydrogenation reaction is basically impossible; above 800℃, the hydrogenation reaction is too vigorous, further increasing energy consumption. On the one hand, hydrogen gas intensifies the corrosion of the inert layer on the inner surface of the reactor, reducing the reactor's lifespan; on the other hand, at high temperatures, hydrogen gas has an excessively high ability to penetrate the reactor's inner material, affecting the reactor's sealing and safety.

[0102] Preferably, the optimal range of hydrogenation reaction temperature in step 2 is 400℃~700℃.

[0103] Specifically, in step 1, the inert gas is any one of helium (He), neon (Ne), or argon (Ar).

[0104] This invention discloses an active beryllium element, which is obtained by hydrogenating naturally occurring metallic beryllium to remove surface beryllium oxide using the method described above. This active beryllium element can react directly with water, chlorine, or dilute acid.

[0105] This invention discloses anhydrous beryllium chloride, prepared by the above-described method for preparing anhydrous beryllium chloride, wherein the beryllium chloride content is ≥99.6% and the water content of the anhydrous beryllium chloride is ≤0.2%.

[0106] This invention discloses a method for determining the purity of anhydrous beryllium chloride, referring to standard GJB2513A-2008 Chemical Analysis Methods for Beryllium, and the determination of moisture content refers to standard GB / T 13025.3-2012 General Test Methods for Salt Production Industry.

[0107] To further illustrate the technical solution of the present invention, the following embodiments and comparative examples are provided:

[0108] Example 1

[0109] This embodiment uses naturally occurring metallic beryllium (purity ≥98%) and chlorination with chlorine gas to prepare anhydrous beryllium chloride, including the following steps:

[0110] Step 1: Place metallic beryllium powder with a particle size of 15μm into a sealed reactor, evacuate twice to a vacuum degree of 0.01MPa, and introduce argon gas for 10min after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0111] Step 2: Hydrogen gas is introduced into a closed reactor to hydrogenate metallic beryllium powder, removing beryllium oxide from the surface of elemental beryllium to prepare active elemental beryllium; the mass ratio of metallic beryllium added to the closed reactor to the flow rate of hydrogen gas is 1g:10ccm; the introduction time is 30min; the hydrogenation reaction temperature is controlled at 200℃.

[0112] Step 3: Introduce argon gas into the sealed reactor again to form an inert atmosphere. Evacuate twice, and introduce argon gas for 10 minutes after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0113] Step 4: Introduce chlorine gas into a closed reactor. The ratio of the mass of beryllium powder added to the flow rate of chlorine gas is 1g:100ccm. The introduce gas for 3 hours. The chlorination reaction temperature is increased at a rate of 1℃ / min. Chlorination reaction is carried out at 500℃ to obtain beryllium chloride.

[0114] Step 5: The beryllium chloride crystals obtained in Step 4 are subjected to temperatures of 180℃ and 240℃ and pressures ≤2×10⁻⁶. -2 Anhydrous beryllium chloride and tantalum chloride were obtained by gradual sublimation and purification at 350℃.

[0115] Example 2

[0116] This embodiment uses naturally occurring metallic beryllium (purity ≥98%) and chlorination with chlorine gas to prepare anhydrous beryllium chloride, including the following steps:

[0117] Step 1: Place metallic beryllium with a particle size of 250μm in a sealed reactor, evacuate 2-3 times to a vacuum degree of 0.3MPa, and introduce neon gas for 40 minutes after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0118] Step 2: Hydrogen gas is introduced into a closed reactor to hydrogenate beryllium powder, removing beryllium oxide from the surface of elemental beryllium to prepare active elemental beryllium; the mass ratio of beryllium powder added to the closed reactor to the flow rate of hydrogen gas is 1g:80ccm; the hydrogenation time is 150min; the hydrogenation reaction temperature is controlled at 800℃.

[0119] Step 3: Introduce neon gas into the sealed reactor again to form an inert atmosphere, evacuate twice, and introduce argon gas for 40 minutes after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0120] Step 4: Introduce chlorine gas into a closed reactor. The ratio of the mass of beryllium powder added to the flow rate of chlorine gas is 1g:200ccm. The introduce gas for 16 hours. The chlorination reaction temperature is increased at a rate of 8℃ / min. The chlorination reaction is carried out at 1200℃ to obtain beryllium chloride.

[0121] Step 5: The beryllium chloride crystals obtained in Step 4 are subjected to temperatures of 200℃ and 250℃ and pressures ≤1×10⁻⁶. -2 Anhydrous beryllium chloride and tantalum chloride were obtained by gradual sublimation and purification at 430℃.

[0122] Example 3

[0123] This embodiment uses naturally occurring metallic beryllium (purity ≥98%) and chlorination with chlorine gas to prepare anhydrous beryllium chloride, including the following steps:

[0124] Step 1: Place metallic beryllium with a particle size of 100μm in a sealed reactor, evacuate twice to a vacuum degree of 0.1MPa, and introduce argon gas for 20min after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0125] Step 2: Hydrogen gas is introduced into a closed reactor to hydrogenate beryllium powder, removing beryllium oxide from the surface of elemental beryllium to prepare active elemental beryllium; the mass ratio of beryllium powder added to the closed reactor to the flow rate of hydrogen gas is 1g:50ccm; the hydrogenation time is 100min; the hydrogenation reaction temperature is controlled at 600℃.

[0126] Step 3: Introduce argon gas into the sealed reactor again to form an inert atmosphere. Evacuate twice, and introduce argon gas for 20 minutes after each evacuation. Repeat this process multiple times to form an inert atmosphere.

[0127] Step 4: Introduce chlorine gas into a closed reactor. The ratio of the mass of beryllium powder added to the flow rate of chlorine gas is 1g:150ccm. The introduce gas for 10 hours. The chlorination reaction temperature is increased at a rate of 15℃ / min. The chlorination reaction is carried out at 1000℃ to obtain beryllium chloride.

[0128] Step 5: The beryllium chloride crystals obtained in Step 4 are subjected to temperatures of 190℃ and 250℃ and pressures ≤1.5×10⁻⁶. -2 torr, gradually sublimated and purified at 400℃ to obtain anhydrous beryllium chloride and tantalum chloride.

[0129] Example 4

[0130] In this embodiment, anhydrous beryllium chloride is prepared by chlorination of naturally occurring metallic beryllium (purity ≥98%) and chlorine gas. The only difference from Example 3 is that the hydrogenation reaction temperature is 400℃.

[0131] Example 5

[0132] In this embodiment, anhydrous beryllium chloride is prepared by chlorination of naturally occurring metallic beryllium (purity ≥98%) and chlorine gas. The only difference from Example 3 is that the hydrogenation reaction temperature is 700℃.

[0133] Example 6

[0134] In this embodiment, natural-state metallic beryllium (purity ≥98%) and chlorination with chlorine gas are used to prepare anhydrous beryllium chloride. The only difference from Example 3 is that the mass ratio of beryllium powder added to the hydrogenation reaction is 1g:20ccm.

[0135] Example 7

[0136] In this embodiment, natural-state metallic beryllium (purity ≥98%) and chlorination with chlorine gas are used to prepare anhydrous beryllium chloride. The only difference from Example 3 is that the mass of beryllium powder added in the hydrogenation reaction is 1g:60ccm.

[0137] Example 8

[0138] In this embodiment, natural-state metallic beryllium (purity ≥98%) and chlorine gas were used to prepare anhydrous beryllium chloride. The only difference from Example 3 is that the chlorination reaction temperature was increased at a rate of 10℃ / min.

[0139] Example 9

[0140] In this embodiment, anhydrous beryllium chloride is prepared by chlorination of naturally occurring metallic beryllium (purity ≥98%) and chlorine gas. The only difference from Example 3 is that the chlorination reaction temperature is 700℃.

[0141] Example 10

[0142] In this embodiment, anhydrous beryllium chloride is prepared by direct chlorination of naturally occurring metallic beryllium (purity ≥98%) and chlorine. The only difference from Example 3 is that the chlorination reaction temperature is 1200℃.

[0143] Comparative Example 1

[0144] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then chlorinating it with chlorine gas. The only difference from Example 3 is that the ratio of the mass of beryllium powder added to the flow rate of hydrogen gas during the hydrogenation reaction is 1g:5ccm.

[0145] Comparative Example 2

[0146] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring metallic beryllium (purity ≥98%) and then chlorinating it with chlorine gas. The only difference from Example 3 is that the ratio of the mass of beryllium powder added to the flow rate of hydrogen gas during the hydrogenation reaction is 1g:100ccm.

[0147] Comparative Example 3

[0148] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then chlorinating it with chlorine gas. The only difference from Example 3 is that the hydrogenation reaction temperature was 150°C.

[0149] Comparative Example 4

[0150] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the hydrogenation reaction temperature was 900℃.

[0151] Comparative Example 5

[0152] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring metallic beryllium (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the ratio of the mass of beryllium powder added to the flow rate of chlorine gas in the chlorination reaction is 1g:80ccm.

[0153] Comparative Example 6

[0154] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring metallic beryllium (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the ratio of the mass of beryllium powder added to the flow rate of chlorine gas in the chlorination reaction is 1g:250ccm.

[0155] Comparative Example 7

[0156] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the chlorination reaction temperature was 400℃.

[0157] Comparative Example 8

[0158] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the chlorination reaction temperature was 1300℃.

[0159] Comparative Example 9

[0160] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that the chlorination reaction heating rate was 18℃ / min.

[0161] Comparative Example 10

[0162] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring beryllium metal (purity ≥98%) and then directly chlorinating it with chlorine gas. The only difference from Example 3 is that no hydrogenation treatment was performed.

[0163] Comparative Example 11

[0164] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring metallic beryllium (purity ≥98%) and then directly chlorinating it with chlorine. The only difference from Example 3 is that the beryllium chloride prepared in step 4 was not subjected to low-temperature sublimation treatment.

[0165] Comparative Example 12

[0166] Anhydrous beryllium chloride was prepared by hydrogenating naturally occurring metallic beryllium (purity ≥98%) and then directly chlorinating it with chlorine. The only difference from Example 3 is that the beryllium chloride prepared in step 4 was not subjected to medium-temperature sublimation treatment.

[0167] Experimental Example

[0168] Examples 1-10 and Comparative Examples 1-12 were tested according to the disclosed method to determine the beryllium chloride purity in the product prepared in step 4, the anhydrous beryllium chloride yield in steps 1-4, and the beryllium chloride purity in the product prepared in step 5, the anhydrous beryllium chloride yield after sublimation purification in step 5, and the water content of anhydrous beryllium chloride. The results are shown in Table 1.

[0169] Table 1 Test data for anhydrous beryllium chloride

[0170]

[0171]

[0172] Results analysis:

[0173] This invention employs hydrogenation treatment of beryllium oxide on the surface of beryllium powder with hydrogen gas, and then reacts the hydrogenated beryllium powder directly with chlorine gas. After chlorination, the yield of anhydrous beryllium chloride can reach 58.2% to 85.3%, and the beryllium chloride content can reach 80.3% to 94.6%.

[0174] It should be noted that the yield of this invention refers to the ratio of the actual output of the product to the theoretical output of the product.

[0175] This invention purifies beryllium chloride by sublimation at different temperature stages, utilizing the different boiling points of chlorides generated from the reaction of metallic impurities and chlorine gas for stepwise purification. The beryllium chloride sublimation process achieves separation and purification of beryllium chloride, and also separates beryllium chloride from metallic impurities such as silicon, aluminum, and iron, which are present in small amounts, thus improving the purity of anhydrous beryllium chloride. Simultaneously, it recovers the rare metal tantalum from beryllium ore. After purification, the beryllium chloride content is ≥99.6%, and the moisture content of anhydrous beryllium chloride is ≤0.2%.

[0176] Comparing Example 3 and Comparative Example 10, it can be seen that the yield of anhydrous beryllium chloride prepared by the initial condensation in step 4 is significantly improved after hydrogenation treatment, increasing from 12.4% to 85.3%. In fact, even without hydrogenation treatment, metallic beryllium will partially undergo chlorination. This is because the presence of metal impurities such as iron and aluminum destroys the dense structure of surface beryllium oxide, so some beryllium can undergo chlorination reaction like the impurities. The introduction of impurities will also have an adverse effect on the beryllium chloride content and the yield of anhydrous beryllium chloride in the sublimation purified in step 5.

[0177] Comparing Example 3 and Comparative Example 1, it is evident that reducing the hydrogen flow rate resulted in incomplete removal of beryllium oxide from the surface of metallic beryllium in Comparative Example 1 within the same gas flow time, thus significantly impacting the yield of anhydrous beryllium chloride (the yield of anhydrous beryllium chloride in steps 1-4 decreased from 85.3% in Example 3 to 15.2% in Comparative Example 1). This indicates that hydrogenation can remove beryllium oxide from the surface of elemental beryllium, allowing elemental beryllium and chlorine to react smoothly to obtain beryllium chloride. Furthermore, comparing Example 3 and Comparative Example 2, it is clear that an excessively high hydrogen flow rate has no effect on the beryllium chloride content or the water content of anhydrous beryllium chloride.

[0178] Comparing Example 3 with Comparative Examples 5-8, it can be seen that excessively high or low temperatures during the chlorination stage, or excessively small or large chlorination gas flow rates, have no effect on the beryllium chloride content or the moisture content of anhydrous beryllium chloride.

[0179] Comparing Example 3 with Comparative Examples 11 and 12, it can be seen that without low-temperature or medium-temperature sublimation treatment, the iron, aluminum, and tantalum impurities associated with beryllium were not separated, and the beryllium content in anhydrous beryllium chloride decreased.

[0180] Table 1 addresses the recovery of tantalum. Because the tantalum content in the beryllium used in the experiment was low, it could not be directly measured under the existing experimental conditions. A comparison between Example 3 and Comparative Example 12 shows that the yield and content of anhydrous beryllium chloride in the final product obtained without the sublimation separation step of tantalum chloride and beryllium chloride were both reduced.

[0181] The above description is only a preferred 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 conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A process for the preparation of anhydrous beryllium chloride, characterized in that, The natural state metal beryllium is treated on the surface by hydrogen, and then is chlorinated by chlorine to prepare anhydrous beryllium chloride; The preparation method comprises the following steps: Step 1: placing the natural state metal beryllium in a closed reactor, and introducing inert gas to form an inert atmosphere; Step 2: introducing hydrogen into the closed reactor to hydrogenate the natural state metal beryllium; in step 2, the mass of the natural state metal beryllium is 1g, and the flow rate of the introduced hydrogen is (10-80) ccm; the hydrogenation treatment reaction temperature is 200-800 DEG C; the particle size of the natural state metal beryllium is 15-250 microns; Step 3: introducing inert gas into the closed reactor again to form an inert atmosphere; Step 4: introducing chlorine into the closed reactor to obtain beryllium chloride through chlorination reaction; in step 4, the chlorination reaction temperature is 700-1000 DEG C; Step 5: sublimating and purifying the beryllium chloride obtained in step 4, which comprises three temperature stages of sublimation and purification, including: low-temperature sublimation stage: heating the beryllium chloride prepared in step 4 at 180-200 DEG C to complete the sublimation of aluminum, iron impurities and the separation of beryllium chloride; medium-temperature sublimation stage: heating the crude beryllium chloride after the low-temperature sublimation at 240-260 DEG C to complete the sublimation of tantalum impurities and the separation of beryllium chloride, and cooling to recover the rare metal tantalum; high-temperature sublimation stage: heating the crude beryllium chloride after the medium-temperature sublimation at 350-430 DEG C to complete the sublimation of beryllium chloride and the separation of beryllium chloride and magnesium, calcium and silicon impurities.

2. The method of claim 1, wherein the anhydrous beryllium chloride is prepared by, In step 4, the mass of the natural state metal beryllium is 1g, and the flow rate of the introduced chlorine is (100-200) ccm.

3. The method of claim 1, wherein the anhydrous beryllium chloride is prepared by the steps of: In step 4, the heating rate of the chlorination reaction is ≤15 DEG C / min.

4. The method of claim 1, wherein the anhydrous beryllium chloride is prepared by the steps of: The purity of the natural state metal beryllium is ≥98%.

5. The method of claim 1, wherein the anhydrous beryllium chloride is prepared by the steps of: The hydrogenation treatment reaction temperature is 400-700 DEG C.

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