阅读说明：本技术 一种利用氟锗酸钡热分解制备高纯四氟化锗的方法 (Method for preparing high-purity germanium tetrafluoride by thermal decomposition of barium fluorogermanate ) 是由 柴皓茗 普世坤 张红萧 熊浩 邵雨萌 尹国文 罗中旭 王东 于 2021-07-07 设计创作，主要内容包括：本发明属于四氟化锗制备技术领域,具体公开一种利用氟锗酸钡热分解制备高纯四氟化锗的方法,包括以下步骤：将可溶性二氧化锗溶解于氢氟酸溶液,制成氟锗酸溶液,所述氢氟酸的浓度为25mol/L,氢氟酸溶液和可溶性二氧化锗的摩尔比为6～6.25：1；在氟锗酸溶液中加入钡盐生成氟锗酸钡沉淀；将生成的氟锗酸钡沉淀使用无水乙醇清洗去除氟化氢残留,放入模具中压成块状,进行烘干,本发明使用氟锗酸钡在600℃～700℃可快速分解生成四氟化锗,锗的收率高,其固体副产物氟化钡具有非常广泛的应用领域和科学应用研究价值。其反应不需要氟气参与,对反应装置的要求低,配置简单,容易控制,其热分解生产的四氟化锗纯度高,杂质少。(The invention belongs to the technical field of germanium tetrafluoride preparation, and particularly discloses a method for preparing high-purity germanium tetrafluoride by utilizing thermal decomposition of barium fluogermanate, which comprises the following steps: dissolving soluble germanium dioxide in a hydrofluoric acid solution to prepare a fluorogermanic acid solution, wherein the concentration of hydrofluoric acid is 25mol/L, and the molar ratio of the hydrofluoric acid solution to the soluble germanium dioxide is 6-6.25: 1; adding barium salt into the fluogermanic acid solution to generate a fluogermanic acid barium precipitate; the generated barium fluorogermanate precipitate is cleaned by absolute ethyl alcohol to remove hydrogen fluoride residues, and is put into a die to be pressed into blocks for drying. The reaction does not need fluorine gas, the requirement on a reaction device is low, the configuration is simple, the control is easy, and the germanium tetrafluoride produced by thermal decomposition has high purity and less impurities.)

1. The preparation method of barium fluorogermanate is characterized by comprising the following steps of:

s1: dissolving soluble germanium dioxide in a hydrofluoric acid solution to prepare a fluorogermanic acid solution, wherein the molar ratio of the hydrofluoric acid solution to the soluble germanium dioxide is 6-6.25: 1;

s2: adding soluble barium salt into the fluogermanic acid solution to generate a fluogermanic acid barium precipitate;

s3: and cleaning the generated barium fluorogermanate precipitate by using absolute ethyl alcohol to remove residual hydrogen fluoride, putting the precipitate into a die, pressing the precipitate into blocks, and drying the blocks.

2. The method of claim 1, wherein the concentration of hydrofluoric acid in step S1 is 25 mol/L.

3. The method according to claim 1, wherein the barium salt in step S2 is BaCl₂Or Ba (NO)₃)₂。

4. The method of claim 3, wherein the barium salt is BaCl₂，BaCl₂And the mol ratio of the fluorine germanic acid solution to the fluorine germanic acid solution is 1.2-1.5: 1.

5. The method of claim 1, wherein the germanium dioxide is 6N high purity germanium dioxide.

6. The application of the barium fluorogermanate prepared by the preparation method of the barium fluorogermanate according to the claim 1, 2, 3, 4 or 5 in preparing high-purity germanium tetrafluoride.

7. Use according to claim 6, characterized in that it comprises the following steps: and putting the dried barium fluorogermanate into a quartz tube, wherein one end of the quartz tube is closed, the other end of the quartz tube is connected with a cooling collector, heating to 600-800 ℃ under the protection of dry nitrogen, reacting for 1-2 h, thermally decomposing the barium fluorogermanate to generate germanium tetrafluoride, cooling and collecting for many times, and then vacuumizing to obtain the high-purity germanium tetrafluoride.

8. The high-purity germanium tetrafluoride preparation device is characterized by comprising a quartz tube, a multistage cooling collector and a collecting bottle which are sequentially connected by using a pipeline, wherein the quartz tube is further connected with a nitrogen supply device and a tail gas absorption device, a dried barium fluogermanate block is arranged in the quartz tube, treatment liquid is arranged in the tail gas absorption device and is water, and the multistage cooling collector is provided with a vacuum suction port and a pressure gauge.

9. The apparatus of claim 8, wherein the material used in the apparatus is monel or hastelloy.

Technical Field

The invention belongs to the technical field of germanium tetrafluoride preparation, and particularly relates to a method for preparing high-purity germanium tetrafluoride by thermal decomposition of barium fluorogermanate.

Background

The high-purity germanium tetrafluoride is mainly used as an intermediate for separating germanium isotopes in the nuclear industry field, can be used as a doping agent and an ion implantation agent in the semiconductor industry, and mainly comprises the following preparation methods:

(a) reacting elemental metal germanium with fluorine gas:

Ge+2F₂→GeF₄

(b) reacting germanium dioxide with bromine trifluoride:

3GeO₂+4BrF₃→3GeF₄+3O₂+2Br₂

the method (a) of manufacturing germanium tetrafluoride is disclosed in application No. 200980138501.3, which is a method of manufacturing germanium tetrafluoride in which diluted fluorine gas is reacted with a germanium block heated to a certain temperature on a rack, and the germanium tetrafluoride is condensed and collected. The reaction is rapid and accompanied by a large exotherm, the rate of which is difficult to control. In its embodiment, there is an example of a local burn reactor by the reaction heat of the germanium lump. The reaction using diluted fluorine gas can effectively control the reaction rate, but is not favorable for high-efficiency production. And the reaction container needs to be opened for feeding materials each time, so that the safety risk is increased, and the resource waste is increased by condensing the fluorine gas-germanium tetrafluoride mixed gas containing the diluent gas.

In actual production, the germanium tetrafluoride manufacturing process of process (a) is limited by the purity of the fluorine gas. The highest purity of GB/T26251-2010 for fluorine gas execution in China is 99.0%, and fluorine gas is filled in a fluorine-nitrogen mixed gas mode because the nature of the fluorine gas is active, so that the fluorine gas for producing high-purity germanium tetrafluoride is difficult to obtain in the market.

Although process (b) can be produced quantitatively, the byproduct can introduce excessive impurities into germanium tetrafluoride.

Electronic grade germanium tetrafluoride as an ion implantation agent has great application value in the semiconductor industry, but the purity is required to be more than 7N, so that the quantitative and stable production of high-purity germanium tetrafluoride is urgent.

Disclosure of Invention

The invention mainly aims to provide a method for preparing high-purity germanium tetrafluoride by utilizing thermal decomposition of barium fluorogermanate, so as to solve the technical problem of preparation of the germanium tetrafluoride and obtain high-purity electronic grade germanium tetrafluoride.

In order to achieve the above purpose, the invention provides the following technical scheme:

s1: dissolving soluble germanium dioxide in a hydrofluoric acid solution to prepare a fluorogermanic acid solution, wherein the molar ratio of the hydrofluoric acid solution to the soluble germanium dioxide is 6-6.25: 1;

s2: adding soluble barium salt into the fluogermanic acid solution to generate a fluogermanic acid barium precipitate;

s3: and cleaning the generated barium fluorogermanate precipitate by using absolute ethyl alcohol to remove residual hydrogen fluoride, putting the precipitate into a die, pressing the precipitate into blocks, and drying the blocks.

The technical scheme comprises the following steps:

(1) dissolving soluble germanium dioxide in hydrofluoric acid solution to obtain fluorogermanic acid solution.

Germanium dioxide is white powder and can be obtained by hydrolysis reaction of germanium tetrachloride, and has three different forms: amorphous glass, hexagonal system, tetragonal system, amorphous glass and hexagonal system germanium dioxide are soluble in water and hydrofluoric acid, and tetragonal system germanium dioxide is insoluble in hydrofluoric acid. The tetragonal system can be melted by heating to above 1086 +/-5 ℃ and then rapidly cooled to obtain amorphous vitreous germanium dioxide. The hexagonal germanium dioxide obtained by hydrolyzing germanium tetrachloride can be directly used for production.

The mol ratio of the soluble germanium dioxide in the hydrofluoric acid solution to the soluble germanium dioxide is 6: 1 can be completely dissolved in the solution, and the following reactions can occur:

GeO₂+6HF＝H₂GeF₆+2H₂O

GeO₂+H₂O＝H₂GeO₃

GeO₂+2H₂O＝H₄GeO₄

5GeO₂+H₂O＝H₂Ge₅O₁₁

7GeO₂+2H₂O＝H₄Ge₇O₁₆

wherein H₂GeO₃、H₄GeO₄、H₂Ge₅O₁₁、H₄Ge₇O₁₆In the case of an excess of hydrofluoric acid. In order to improve the recovery and utilization rate of germanium, the hydrofluoric acid is excessive.

(2) Adding soluble barium salt (Ba) into the fluogermanic acid solution²⁺) And generating a barium fluogermanate precipitate.

Adding BaCl into the fluorogermanic acid solution₂Or Ba (NO)₃)₂Will form white granular BaGeF₆Precipitation, stirring can accelerate the formation of the precipitate, and the following reactions occur:

Ba²⁺+H₂GeF₆＝BaGeF₆+2H²⁺

barium salt (Ba) is added to improve the recovery rate of germanium and reduce the difficulty of waste liquid treatment²⁺) It should be in excess.

(3) Filtering, washing, briquetting and drying the barium fluorogermanate precipitate to obtain anhydrous barium fluorogermanate

Filtering to obtain barium fluorogermanate precipitate, and cleaning with anhydrous ethanol to remove hydrogen fluoride residue. The blocky barium fluogermanate can reduce the introduction of solid impurities and improve the product purity in the thermal decomposition reaction for producing germanium tetrafluoride. And (4) drying after briquetting, setting the drying temperature at 70 ℃, drying for 10h, and removing crystal water to ensure that the caking is firmer. If the crystal water in the barium fluogermanate is not completely removed, the crystal water can react with germanium tetrafluoride to generate HF to corrode the device in the thermal decomposition reaction process.

(4) Thermally decomposing anhydrous barium fluorogermanate to obtain germanium tetrafluoride

And putting the dried barium fluogermanate into a quartz tube, wherein one end of the quartz tube is closed, and the other end of the quartz tube is connected with a cooling collector. Heating to 600-800 ℃ under the protection of dry nitrogen, and reacting for 1-2 h, wherein the higher the temperature is, the faster the reaction rate is.

BaGeF₆→BaF₂+GeF₄

(5) Cooling and collecting the generated germanium tetrafluoride to obtain the germanium tetrafluoride

Germanium tetrafluoride generated in the quartz tube quickly overflows to the cooling collector due to its high vapor pressure. The temperature of the cooling and collecting device is-80 to-50 ℃, germanium tetrafluoride is desublimated at the temperature of-36.5 ℃ under normal pressure, and the collection rate can be improved by reducing the cooling temperature. After the reaction is finished, the cooling collector containing the germanium tetrafluoride crystal is vacuumized to-0.1 to-0.09 MPa.

(6) Purification of germanium tetrafluoride to prepare high-purity germanium tetrafluoride

And cooling and collecting the collected germanium tetrafluoride for multiple times, vacuumizing, and removing light impurities to obtain the high-purity germanium tetrafluoride. And then raising the temperature of the collector to volatilize the germanium tetrafluoride, opening a valve of a steel cylinder for collection, controlling the temperature of the steel cylinder to be minus 30-0 ℃, stopping filling until the pressure of the steel cylinder is obviously changed, and obtaining the finished product of the high-purity germanium tetrafluoride.

The method can rapidly decompose the barium fluorogermanate at 600-700 ℃ to generate germanium tetrafluoride, the yield of germanium is high, and the solid by-product barium fluoride has very wide application fields and scientific application and research values. The reaction does not need fluorine gas, the requirement on a reaction device is low, the configuration is simple, the control is easy, and the germanium tetrafluoride produced by thermal decomposition has high purity and less impurities.

Drawings

FIG. 1 is a flow chart of the process for preparing barium fluorogermanate in accordance with the present invention;

FIG. 2 is a flow chart of the method of the present invention for preparing high purity germanium tetrafluoride by thermal decomposition of barium fluorogermanate;

wherein:

1. blocky barium fluorogermanate; 2. an oven; 3. a quartz tube; 4. drying nitrogen; 5. a primary cooling collector; 6. a secondary cooling collector; 7. a third stage cooling collector; 8. collecting the gas cylinder; 9. and a tail gas outlet.

Detailed Description

The method for preparing high-purity germanium tetrafluoride by thermal decomposition of barium fluorogermanate according to the present invention will be described in detail below with reference to the accompanying drawings and examples, and the chemical reagents used in the present invention are superior pure reagents and can be purchased from the market without any particular description.

Example 1

At the temperature of 25 ℃, 100g of soluble germanium dioxide is put into 250mL of 25mol/L HF hydrofluoric acid solution, and the mixture is stirred for 10min, so that the prepared mixed solution of the germanium fluoacid and the hydrofluoric acid is clear and transparent. 205g of BaCl were added₂Stirring the powder for 10min to fully precipitate, and then, a white granular precipitate appears in the solution. After filtration, the crystals were washed once with pure water and three times with absolute ethanol. Pressing into 10 × 10mm blocks, placing into an oven, setting the drying temperature at 70 deg.C, and drying for 10 hr to obtain 311.7g product. The germanium dioxide and hydrofluoric acid completely react, and the molar ratio of the hydrofluoric acid solution to the soluble germanium dioxide is 6.53: 1, greater than 6-6.25: 1, after the germanium dioxide completely reacts, a large amount of hydrogen fluoride remains in the solution, barium chloride reacts with hydrofluoric acid after barium salt is added, and the generated barium fluoride slightly soluble in water is mixed in the barium fluorogermanate to influence the subsequent thermal decomposition yield.

Example 2

And (3) putting 100g of soluble germanium dioxide into 235mL of 25mol/L HF hydrofluoric acid solution at the temperature of 25 ℃, and stirring for 10min, so that the prepared mixed solution of the fluorogermanic acid and the hydrofluoric acid is clear and transparent. 205g of BaCl were added₂Stirring for 10min to precipitate. A white granular precipitate appeared in the solution. After filtration, the crystals were washed once with pure water and three times with absolute ethanol. Pressing into 10 × 10mm blocks, oven drying at 70 deg.C for 10 hr to obtain 307.9g product, and detecting by thermogravimetry to obtain barium fluorogermanate containingThe amount is 99.6%, and the comprehensive recovery rate of germanium is 99.0%.

And introducing dry nitrogen 4 into the quartz tube, performing gas replacement on the system, and putting the prepared 100.0g of blocky barium fluorogermanate into the quartz tube 3, wherein the pressure in the quartz tube is normal pressure. The temperature of the quartz tube is set to 700 ℃, the temperature of the primary cooling collector 5 is set to-70 ℃, and the pressure change of the quartz tube is observed to judge the reaction progress degree. After heating for about 40min, the pressure does not change obviously. In order to fully decompose the barium fluorogermanate, the heating temperature is kept to 1 h. The first-stage cooling collection time is consistent with the reaction time. After the reaction is finished, a connecting valve between the quartz tube and the primary cooling collector is closed, a tail gas outlet 9 is opened, dry nitrogen is introduced into the quartz tube, and germanium tetrafluoride is blown out. And the tail gas treatment liquid is water, the quartz tube is opened after the treatment is finished, and barium fluoride crystals in the tube are taken out and stored in a dry place.

And (3) closing a valve between the first-stage cooling collector, the second-stage cooling collector and the third-stage cooling collector 6 and 7, and vacuumizing the three cooling collectors to-0.1 MPa. And opening connecting valves of the first-stage cooling collector and the second-stage cooling collector, wherein the temperature of the second-stage cooling collector is-70 ℃, and the temperature of the first-stage cooling collector is slowly increased to 10 ℃. And observing the pressure gauge, reducing the pressure value after the pressure value is increased, finishing the secondary cooling collection when the pressure is not reduced, closing the connecting valves of the primary cooling collector and the secondary cooling collector, and vacuumizing the secondary cooling collector to-0.1 MPa. And (5) circulating operation until the third-stage cooling and collection are completed, setting the temperature of a filling steel cylinder to be-30 ℃, and filling the product. 45.0g of germanium tetrafluoride with the concentration of over 99.9 percent is obtained by detection and weighing, and the comprehensive germanium yield is 97.6 percent.

Example 3

At the temperature of 25 ℃, 500g of soluble germanium dioxide is put into 1.15L of 25mol/L HF hydrofluoric acid solution, and the mixture is stirred for 20min, so that the prepared mixed solution of the germanium fluoacid and the hydrofluoric acid is clear and transparent. 990.0g of BaCl was added₂Stirring the powder for 30min to fully precipitate. A white granular precipitate appeared in the solution. After filtration, the crystals were washed once with pure water and three times with absolute ethanol. Pressing into 10 × 10mm block, oven drying at 70 deg.C for 10 hr to obtain 1546.7g product, and detecting by thermogravimetry to obtain barium fluorogermanate with content of 99.7% and germanium contentThe recovery rate is 99.6%.

And introducing dry nitrogen 4 into the quartz tube, performing gas replacement on the system, and putting 1000.0g of the prepared blocky barium fluorogermanate into the quartz tube 3, wherein the pressure in the quartz tube is normal pressure. The temperature of the quartz tube is set to 650 ℃, the temperature of the primary cooling collector 5 is set to-70 ℃, and the reaction progress degree is judged by observing the pressure change of the quartz tube. After heating for about 60min, the pressure does not change obviously. Heating to 1.5h is kept for fully decomposing the barium fluorogermanate. The first-stage cooling collection time is consistent with the reaction time. After the reaction is finished, a connecting valve between the quartz tube and the primary cooling collector is closed, a tail gas outlet 9 is opened, dry nitrogen is introduced into the quartz tube, and germanium tetrafluoride is blown out. And the tail gas treatment liquid is water, the quartz tube is opened after the treatment is finished, and barium fluoride crystals in the tube are taken out and stored in a dry place.

And (3) closing a valve between the first-stage cooling collector, the second-stage cooling collector and the third-stage cooling collector 6 and 7, and vacuumizing the three cooling collectors to-0.1 MPa. And opening connecting valves of the first-stage cooling collector and the second-stage cooling collector, wherein the temperature of the second-stage cooling collector is-70 ℃, and the temperature of the first-stage cooling collector is slowly increased to 10 ℃. And observing the pressure gauge, reducing the pressure value after the pressure value is increased, finishing the secondary cooling collection when the pressure is not reduced, closing the connecting valves of the primary cooling collector and the secondary cooling collector, and vacuumizing the secondary cooling collector to-0.1 MPa. And (5) circulating operation until the third-stage cooling and collection are completed, setting the temperature of a filling steel cylinder to be-30 ℃, and filling the product. 433.5g of germanium tetrafluoride with the concentration of more than 99.9 percent is obtained by detection and weighing, and the comprehensive germanium yield is 96.0 percent.

Controlling the hydrofluoric acid excess increases the reaction level of germanium dioxide, and too much excess can result in barium fluoride contamination in the product.

Example 4

And (3) putting 100g of soluble germanium dioxide into 235mL of 25mol/L HF hydrofluoric acid solution at the temperature of 25 ℃, and stirring for 10min, so that the prepared mixed solution of the fluorogermanic acid and the hydrofluoric acid is clear and transparent. 260.0g of Ba (NO) was added₃)₂Stirring for 10min to precipitate. A white granular precipitate appeared in the solution. After filtration, the crystals were washed once with pure water and three times with absolute ethanol. Pressing into 10 × 10mm blocks, placing into oven,the drying temperature is set to be 70 ℃, the drying time is 10 hours, 305.6g of the product is obtained, the content of barium fluogermanate is 99.3 percent through thermogravimetric detection, and the comprehensive recovery rate of germanium is 98.0 percent.

And introducing dry nitrogen 4 into the quartz tube, performing gas replacement on the system, and putting the prepared 100.0g of blocky barium fluorogermanate into the quartz tube 3, wherein the pressure in the quartz tube is normal pressure. The temperature of the quartz tube is set to 700 ℃, the temperature of the primary cooling collector 5 is set to-70 ℃, and the pressure change of the quartz tube is observed to judge the reaction progress degree. After heating for about 40min, the pressure does not change obviously. In order to fully decompose the barium fluorogermanate, the heating temperature is kept to 1 h. The first-stage cooling collection time is consistent with the reaction time. After the reaction is finished, a connecting valve between the quartz tube and the primary cooling collector is closed, a tail gas outlet 9 is opened, dry nitrogen is introduced into the quartz tube, and germanium tetrafluoride is blown out. And the tail gas treatment liquid is water, the quartz tube is opened after the treatment is finished, and barium fluoride crystals in the tube are taken out and stored in a dry place.

And (3) closing a valve between the first-stage cooling collector, the second-stage cooling collector and the third-stage cooling collector 6 and 7, and vacuumizing the three cooling collectors to-0.1 MPa. And opening connecting valves of the first-stage cooling collector and the second-stage cooling collector, wherein the temperature of the second-stage cooling collector is-70 ℃, and the temperature of the first-stage cooling collector is slowly increased to 10 ℃. And observing the pressure gauge, reducing the pressure value after the pressure value is increased, finishing the secondary cooling collection when the pressure is not reduced, closing the connecting valves of the primary cooling collector and the secondary cooling collector, and vacuumizing the secondary cooling collector to-0.1 MPa. And (5) circulating operation until the third-stage cooling and collection are completed, setting the temperature of a filling steel cylinder to be-30 ℃, and filling the product. 44.1g of germanium tetrafluoride with the concentration of over 99.9 percent is obtained by detection and weighing, and the comprehensive germanium yield is 96.7 percent.

The present invention is explained based on the above embodiments, but the present invention is not limited by the above embodiments.

The method has the advantages of simple operation, easy control of reaction, high purity of the germanium tetrafluoride product and simple equipment requirement.