Preparation method of ultra-pure germanium dioxide

Abstract

The invention relates to the technical field of preparation of germanium dioxide, in particular to a preparation method of ultra-pure germanium dioxide, which comprises the following steps: grinding a germanium ingot to obtain germanium powder; transferring the germanium powder into a closed reactor, introducing high-purity chlorine into the closed reactor, and fully reacting to obtain germanium tetrachloride; distilling and purifying germanium tetrachloride; adding ultrapure water into the purified germanium tetrachloride, fully stirring, standing, and filtering to obtain germanium dioxide precipitate; and cleaning, drying and calcining the germanium dioxide precipitate to obtain the ultra-high-purity germanium dioxide with the purity of 7N or above. Germanium dioxide obtained by the preparation method of ultra-pure germanium dioxide is high in purity and high in yield, the chlorine content is lower than 0.003%, and the preparation requirements of BGO crystals are met.

Description

Technical Field

[0001] The invention relates to the technical field of germanium dioxide preparation, in particular to a method for preparing ultra-high purity germanium dioxide. Background Art

[0002] Germanium dioxide (GeO2) is a white powder or colorless crystal. It is mainly used to make metallic germanium, and is also used as a spectral analysis and semiconductor material. In the electronics industry, it can be used as a semiconductor material, to make optical glass phosphors, and as a catalyst in processes such as oil refining. Germanium dioxide is also a commonly used material in scientific research, especially in the fields of analytical chemistry and semiconductor materials.

[0003] The current national standard for high-purity germanium dioxide (GB / T 11069-2006) stipulates that its purity should not be less than 99.999% and its chlorine content should not be greater than 0.05%. However, high-purity germanium dioxide used to prepare special germanium crystal materials, such as the use of high-purity germanium dioxide to prepare bismuth germanate crystals (BGO), involves the growth of crystals in a platinum crucible. If the chloride ions in germanium dioxide are too high, when germanium dioxide is melted at high temperature, the chlorine in the germanium dioxide will be released to corrode the platinum crucible and the preparation equipment. Therefore, in the field of preparing BGO, there are higher requirements for germanium dioxide and its chlorine content.

[0004] After searching, the Chinese patent publication number CN109534388A discloses a method for preparing high-purity germanium dioxide, including mixing metal germanium powder with water and heating; adding hydrogen peroxide for oxidation reaction, filtering to obtain filtrate; concentrating the filtrate and crystallizing to obtain germanic acid crystals; and the germanic acid crystals undergo cracking reaction under the condition of passing inert gas to obtain high-purity germanium dioxide. The purity of the germanium dioxide obtained in the above patent can only reach 99.99%, which is difficult to meet the preparation requirements of BGO crystals. In view of this, we propose a method for preparing ultra-high purity germanium dioxide. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing ultra-high purity germanium dioxide to obtain high-purity germanium dichloride of more than 7N and reduce its chlorine content to meet the preparation requirements of BGO crystals.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The method for preparing ultra-high purity germanium dioxide comprises the following steps:

[0008] S1, grinding the germanium ingot to obtain germanium powder;

[0009] S2, transferring the germanium powder to a closed reactor, introducing high-purity chlorine gas thereinto, reacting sufficiently to obtain germanium tetrachloride;

[0010] S3, distilling and purifying germanium tetrachloride;

[0011] S4, adding ultrapure water to the purified germanium tetrachloride, stirring thoroughly and letting stand, filtering to obtain germanium dioxide precipitation;

[0012] S5. Wash, dry and calcine the germanium dioxide precipitate to obtain ultra-high purity germanium dioxide of 7N or above.

[0013] Preferably, in step S1, the particle size of the germanium powder is less than 10 μm.

[0014] Preferably, in step S2, the temperature in the closed reactor is controlled at 60-70° C., the molar ratio of germanium powder to chlorine is 1:1.5-1.8, and the reaction time is 1-6 hours.

[0015] Preferably, step S2 further comprises transferring the germanium powder to a closed reaction container, adding a catalyst, and then introducing high-purity chlorine gas therein, wherein the catalyst is any one of ferric chloride and manganese chloride, and the molar ratio of the catalyst to the germanium powder is 1:10-40.

[0016] Preferably, in step S3, the distillation purification comprises transferring germanium tetrachloride into a distillation flask, heating it, and collecting a fraction at 90-120° C.

[0017] Preferably, in step S4, the volume ratio of germanium tetrachloride to ultrapure water is 1:6-8, and the standing time is 4-20 hours.

[0018] Preferably, in step S5, the cleaning comprises washing the germanium dioxide precipitate with ultrapure water for multiple times, and vacuum filtering the germanium dioxide after washing;

[0019] Drying includes vacuum drying the washed germanium dioxide precipitate at a temperature of 80 to 100° C. for a drying time of 4 to 8 hours;

[0020] The calcination temperature is 600-800° C., the calcination time is 2-8 hours, and the calcination atmosphere is high-purity argon or high-purity nitrogen.

[0021] Preferably, a vacuum drying oven is used to vacuum dry the washed germanium dioxide precipitate, the vacuum drying oven comprising a box body, a box door is hinged on the front side of the box body, a first motor is fixedly arranged at the bottom of the box body, a rotating column is rotatably arranged at the bottom of the inner side of the box body through a bearing, an output end of the first motor passes through the bottom wall of the box body and is fixedly connected to the bottom of the rotating column, and a discharge tray is sleeved on the top of the rotating column;

[0022] A second motor is fixedly arranged above the box body, an output end of the second motor passes through the top wall of the box body and is fixedly connected to a rotating shaft, a U-shaped frame is fixedly connected to the bottom of the rotating shaft, a fixed column is symmetrically arranged at the bottom end of the U-shaped frame, a telescopic rod is connected to the bottom of the fixed column, a stirring paddle is fixedly connected to the bottom end of the telescopic rod, a spring is sleeved on the outer side of the telescopic rod, two ends of the spring are fixedly connected to the fixed column and the stirring paddle respectively, and when the spring is in a normal state, the bottom of the stirring paddle is in clearance with the discharge tray;

[0023] A heating block is arranged inside the box body, a through hole is opened on the side wall of the box body, and the box body is sealed and connected with the vacuum pump pipeline through the through hole.

[0024] Preferably, a support plate is provided on the fixed sleeve on the upper side of the rotating column, and a baffle is fixedly provided on the edge of the discharge tray.

[0025] Preferably, a plurality of support columns are evenly arranged on the bottom of the box body, and the height of the plurality of support columns is greater than the height of the first motor.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] 1. The preparation method of ultra-high purity germanium dioxide comprises the following steps: grinding a germanium ingot to obtain germanium powder, directly gasifying it with chlorine to obtain germanium tetrachloride, and then distilling and purifying the germanium tetrachloride, hydrolyzing, drying, and calcining to obtain high-purity germanium dioxide above 7N, with a chlorine content of less than 0.003%, which meets the preparation requirements of BGO crystals.

[0028] 2. The method for preparing ultra-high purity germanium dioxide can effectively increase the yield of germanium tetrachloride and thus the yield of germanium dioxide by adding a catalyst of ferric chloride or manganese dichloride during the reaction of germanium powder and chlorine.

[0029] 3. The preparation method of ultra-high purity germanium dioxide can remove impurities in germanium dioxide and ensure the purity of germanium dioxide by distilling and purifying germanium tetrachloride, adding ultra-pure water during the hydrolysis process of germanium dioxide, and washing, drying and calcining the germanium dioxide precipitate for multiple times.

[0030] 4. The method for preparing ultra-high purity germanium dioxide uses a vacuum drying oven to vacuum dry the cleaned germanium dioxide precipitate, and controls the stirring paddle and the discharge tray to rotate in opposite directions through the first motor and the second motor, so that the germanium dioxide precipitate is heated evenly and its drying process is accelerated. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a flow chart of the method for preparing ultra-high purity germanium dioxide;

[0032] Figure 2 It is a schematic diagram of the overall structure of the vacuum drying oven in the present invention;

[0033] Figure 3 This is a schematic diagram of the internal structure of the vacuum drying oven in the present invention from a first viewing angle;

[0034] Figure 4 for Figure 3 A magnified view of the structure at center;

[0035] Figure 5 It is a schematic diagram of the internal structure of the vacuum drying box in the present invention from another perspective;

[0036] Figure 6 for Figure 5 Enlarged view of the structure at point B in the middle.

[0037] In the figure: 1. box body; 2. box door; 3. first motor; 4. rotating column; 41. support plate; 5. discharge tray; 51. baffle; 6. second motor; 7. rotating shaft; 8. U-shaped frame; 9. fixed column; 10. telescopic rod; 11. stirring paddle; 12. spring; 13. heating block; 14. through hole; 15. support column. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] The method for preparing ultra-high purity germanium dioxide comprises the following steps:

[0041] S1. Grinding a 6N germanium ingot to obtain germanium powder, wherein the particle size of the germanium powder is less than 10 μm;

[0042] S2, transfer the germanium powder to a closed reactor, add a catalyst of ferric chloride, the molar ratio of the catalyst to the germanium powder is 1:10, the temperature in the closed reactor is controlled at 60°C, high-purity chlorine is introduced therein, the molar ratio of the germanium powder to the chlorine is 1:1.5, the reaction time is 1h, and the reaction is fully reacted to obtain germanium tetrachloride;

[0043] S3, distilling and purifying germanium tetrachloride, including transferring germanium tetrachloride to a distillation flask, heating it, and collecting a fraction at 90° C.;

[0044] S4, adding ultrapure water to the purified germanium tetrachloride, the volume ratio of germanium tetrachloride to ultrapure water being 1:6, stirring thoroughly and letting stand for 4 hours, filtering to obtain germanium dioxide precipitate;

[0045] S5. The germanium dioxide precipitate is cleaned, dried and calcined. The cleaning comprises cleaning the germanium dioxide precipitate with ultrapure water for multiple times. After cleaning, the germanium dioxide is vacuum filtered. The drying comprises vacuum drying the cleaned germanium dioxide precipitate. The drying temperature is 80° C. and the drying time is 8 hours. The calcination temperature is 600° C. and the calcination time is 8 hours. The calcination atmosphere is high-purity argon gas. Germanium dioxide is obtained. Detection by inductively coupled plasma mass spectrometer (ICP-MS) shows that the germanium dioxide is 7N ultra-high purity germanium dioxide. The yield of ultra-high purity germanium dioxide is greater than 98.5%, and the chlorine content is less than 0.003%.

[0046] Example 2

[0047] The method for preparing ultra-high purity germanium dioxide comprises the following steps:

[0048] S1. Grinding a 6N germanium ingot to obtain germanium powder, wherein the particle size of the germanium powder is less than 10 μm;

[0049] S2, transfer the germanium powder to a closed reactor, add a catalyst of ferric chloride, the molar ratio of the catalyst to the germanium powder is 1:20, the temperature in the closed reactor is controlled at 63°C, high-purity chlorine is introduced therein, the molar ratio of the germanium powder to the chlorine is 1:1.6, the reaction time is 2h, and the reaction is fully reacted to obtain germanium tetrachloride;

[0050] S3, distilling and purifying germanium tetrachloride, including transferring germanium tetrachloride to a distillation flask, heating it, and collecting a fraction at 100° C.;

[0051] S4, adding ultrapure water to the purified germanium tetrachloride, the volume ratio of germanium tetrachloride to ultrapure water being 1:6.5, stirring thoroughly and letting stand for 8 hours, filtering to obtain germanium dioxide precipitate;

[0052] S5. The germanium dioxide precipitate is cleaned, dried and calcined. The cleaning comprises washing the germanium dioxide precipitate with ultrapure water for multiple times. After cleaning, the germanium dioxide is vacuum filtered. The drying comprises vacuum drying the cleaned germanium dioxide precipitate. The drying temperature is 85° C. and the drying time is 6 h. The calcination temperature is 650° C. and the calcination time is 6 h. The calcination atmosphere is high-purity argon gas. Germanium dioxide is obtained. Detection by inductively coupled plasma mass spectrometer (ICP-MS) shows that the result is 7N ultra-high purity germanium dioxide. The yield of ultra-high purity germanium dioxide is greater than 98.8%, and the chlorine content is less than 0.003%.

[0053] Example 3

[0054] The method for preparing ultra-high purity germanium dioxide comprises the following steps:

[0055] S1. Grinding a 7N germanium ingot to obtain germanium powder, wherein the particle size of the germanium powder is less than 10 μm;

[0056] S2, transfer the germanium powder to a closed reactor, add a catalyst manganese dichloride, the molar ratio of the catalyst to the germanium powder is 1:30, the temperature in the closed reactor is controlled at 65°C, high-purity chlorine is introduced therein, the molar ratio of the germanium powder to the chlorine is 1:1.7, the reaction time is 4h, and the reaction is fully reacted to obtain germanium tetrachloride;

[0057] S3, distilling and purifying germanium tetrachloride, including transferring germanium tetrachloride to a distillation flask, heating it, and collecting a fraction at 110° C.;

[0058] S4, adding ultrapure water to the purified germanium tetrachloride, the volume ratio of germanium tetrachloride to ultrapure water being 1:7, stirring thoroughly and letting stand for 15 hours, filtering to obtain germanium dioxide precipitate;

[0059] S5. The germanium dioxide precipitate is cleaned, dried and calcined. The cleaning comprises cleaning the germanium dioxide precipitate with ultrapure water for multiple times. After cleaning, the germanium dioxide is vacuum filtered. The drying comprises vacuum drying the cleaned germanium dioxide precipitate. The drying temperature is 90° C. and the drying time is 5 h. The calcination temperature is 700° C. and the calcination time is 4 h. The calcination atmosphere is high-purity nitrogen. Germanium dioxide is obtained. Detection by inductively coupled plasma mass spectrometer (ICP-MS) shows that the germanium dioxide is 8N ultra-high purity germanium dioxide. The yield of ultra-high purity germanium dioxide is greater than 99.2%, and the chlorine content is less than 0.003%.

[0060] Example 4

[0061] The method for preparing ultra-high purity germanium dioxide comprises the following steps:

[0062] S1. Grinding a 7N germanium ingot to obtain germanium powder, wherein the particle size of the germanium powder is less than 10 μm;

[0063] S2, transfer the germanium powder to a closed reactor, add a catalyst manganese dichloride, the molar ratio of the catalyst to the germanium powder is 1:40, the temperature in the closed reactor is controlled at 70°C, high-purity chlorine is introduced therein, the molar ratio of the germanium powder to the chlorine is 1:1.8, the reaction time is 6h, and fully react to obtain germanium tetrachloride;

[0064] S3, distilling and purifying germanium tetrachloride, including transferring germanium tetrachloride to a distillation flask, heating it, and collecting a fraction at 120° C.;

[0065] S4, adding ultrapure water to the purified germanium tetrachloride, the volume ratio of germanium tetrachloride to ultrapure water being 1:8, stirring thoroughly and letting stand for 20 hours, filtering to obtain germanium dioxide precipitate;

[0066] S5. The germanium dioxide precipitate is cleaned, dried and calcined. The cleaning comprises cleaning the germanium dioxide precipitate with ultrapure water for multiple times. After cleaning, the germanium dioxide is vacuum filtered. The drying comprises vacuum drying the cleaned germanium dioxide precipitate. The drying temperature is 100° C. and the drying time is 4 h. The calcination temperature is 800° C. and the calcination time is 2 h. The calcination atmosphere is high-purity nitrogen. Germanium dioxide is obtained. Detection by inductively coupled plasma mass spectrometer (ICP-MS) shows that the germanium dioxide is 8N ultra-high purity germanium dioxide. The yield of the ultra-high purity germanium dioxide is greater than 99.4%, and the chlorine content is less than 0.003%.

[0067] Example 5

[0068] The germanium dioxide precipitates after cleaning in the above examples 1 to 4 were vacuum dried in a vacuum drying oven. Figures 2 to 6 As shown, the vacuum drying box includes a box body 1, a box door 2 is hinged on the front side of the box body 1, a first motor 3 is fixedly arranged at the bottom of the box body 1, a rotating column 4 is rotatably arranged at the bottom of the inner side of the box body 1 through a bearing, an output end of the first motor 3 penetrates the bottom wall of the box body 1 and is fixedly connected to the bottom of the rotating column 4, a discharge tray 5 is sleeved on the top of the rotating column 4, and the rotation of the rotating column 4 is controlled by the first motor 3, thereby driving the discharge tray 5 to rotate, so that the germanium dioxide precipitate is heated evenly;

[0069] A second motor 6 is fixedly arranged above the box body 1, and the output end of the second motor 6 passes through the top wall of the box body 1 and is fixedly connected to a rotating shaft 7, and a U-shaped frame 8 is fixedly connected to the bottom of the rotating shaft 7, and a fixed column 9 is symmetrically arranged at the bottom of the U-shaped frame 8, and a telescopic rod 10 is connected to the bottom of the fixed column 9, and a stirring paddle 11 is fixedly connected to the bottom of the telescopic rod 10, and a spring 12 is sleeved on the outer side of the telescopic rod 10, and the two ends of the spring 12 are respectively fixedly connected to the fixed column 9 and the stirring paddle 11, and when the spring 12 is in a normal state, the stirring paddle 11 is fixedly connected to the bottom of the stirring paddle 11. The stirring paddle 11 is rotated in the opposite direction to the rotation direction of the discharge tray 5, so that the stirring paddle 11 can fully stir the germanium dioxide precipitate on the discharge tray 5; by moving the stirring paddle 11 upward, the telescopic rod 10 is compressed, and the spring 12 is compressed, so that the vertical distance between the stirring paddle 11 and the top of the rotating column 4 is increased, which is convenient for taking and placing the discharge tray 5. After the discharge tray 5 is placed, the stirring paddle 11 can be reset.

[0070] A heating block 13 is arranged inside the box 1, and a through hole 14 is opened on the side wall of the box 1. The box 1 is sealedly connected to a vacuum pump (not shown) pipeline through the through hole 14. The vacuum pump is used to evacuate the inside of the box 1 to accelerate the drying of the germanium dioxide precipitate.

[0071] In this embodiment, a support plate 41 is fixedly sleeved on the upper side of the rotating column 4, and the discharge tray 5 is supported by the support plate 41. A baffle 51 is fixedly provided on the edge of the discharge tray 5, and the baffle 51 can prevent the germanium dioxide precipitate from dispersing during the stirring process.

[0072] In this embodiment, a plurality of support columns 15 are evenly arranged at the bottom of the box body 1 , and the height of the plurality of support columns 15 is greater than the height of the first motor 6 , so as to facilitate the installation of the first motor 6 .

[0073] When the vacuum drying oven of the present embodiment is in use, the cleaned germanium dioxide is placed on the discharge tray 5, the stirring paddle 11 is moved upward, the telescopic rod 10 is compressed, and the spring 12 is compressed to increase the vertical distance between the stirring paddle 11 and the top of the rotating column 4, the discharge tray 5 is sleeved on the support column 4, and supported and fixed by the support plate 41, and then the stirring paddle 11 is reset; the box door 2 is closed, the interior of the box body 1 is heated by the heating block 13, the box body 1 is evacuated by the vacuum pump, and the first motor 3 and the second motor 6 are started at the same time, so that the stirring paddle 11 and the discharge tray 5 rotate in the opposite direction, so that the germanium dioxide precipitate is heated evenly, thereby accelerating its drying process.

[0074] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A method for preparing ultra-high purity germanium dioxide, characterized in that: The following steps are involved: S1, grinding the germanium ingot to obtain germanium powder; S2, transferring the germanium powder to a closed reactor, introducing high-purity chlorine gas thereinto, reacting sufficiently to obtain germanium tetrachloride; S3, distilling and purifying germanium tetrachloride; S4, adding ultrapure water to the purified germanium tetrachloride, stirring thoroughly and letting stand, filtering to obtain germanium dioxide precipitation; S5. Wash, dry and calcine the germanium dioxide precipitate to obtain ultra-high purity germanium dioxide of 7N or above.

2. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: In the step S1, the particle size of the germanium powder is less than 10 μm.

3. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: In step S2, the temperature in the closed reactor is controlled at 60-70° C., the molar ratio of germanium powder to chlorine is 1:1.5-1.8, and the reaction time is 1-6 hours.

4. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: The step S2 further includes transferring the germanium powder to a closed reaction container, adding a catalyst, and then introducing high-purity chlorine gas therein, wherein the catalyst is any one of ferric chloride and manganese chloride, and the molar ratio of the catalyst to the germanium powder is 1:10-40.

5. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: In the step S3, the distillation purification includes transferring the germanium tetrachloride into a distillation flask, heating it, and collecting a fraction at 90-120°C.

6. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: In the step S4, the volume ratio of germanium tetrachloride to ultrapure water is 1:6-8, and the standing time is 4-20 hours.

7. The method for preparing ultra-high purity germanium dioxide according to claim 1, characterized in that: In the step S5, the cleaning comprises washing the germanium dioxide precipitate with ultrapure water for multiple times, and vacuum filtering the germanium dioxide after washing; Drying includes vacuum drying the washed germanium dioxide precipitate at a temperature of 80 to 100° C. for a drying time of 4 to 8 hours; The calcination temperature is 600-800° C., the calcination time is 2-8 hours, and the calcination atmosphere is high-purity argon or high-purity nitrogen.

8. The method for preparing ultra-high purity germanium dioxide according to claim 7, characterized in that: A vacuum drying oven is used to vacuum dry the washed germanium dioxide precipitate, the vacuum drying oven comprising a box body (1), a box door (2) hingedly connected to the front side of the box body (1), a first motor (3) fixedly arranged at the bottom of the box body (1), a rotating column (4) rotatably arranged at the bottom of the inner side of the box body (1) via a bearing, an output end of the first motor (3) passes through the bottom wall of the box body (1) and is fixedly connected to the bottom of the rotating column (4), and a discharge tray (5) is sleeved on the top of the rotating column (4); A second motor (6) is fixedly arranged above the box body (1); an output end of the second motor (6) penetrates the top wall of the box body (1) and is fixedly connected to a rotating shaft (7); a U-shaped frame (8) is fixedly connected to the bottom of the rotating shaft (7); a fixed column (9) is symmetrically arranged at the bottom end of the U-shaped frame (8); a telescopic rod (10) is connected to the bottom of the fixed column (9); a stirring paddle (11) is fixedly connected to the bottom end of the telescopic rod (10); a spring (12) is sleeved on the outer side of the telescopic rod (10); two ends of the spring (12) are fixedly connected to the fixed column (9) and the stirring paddle (11) respectively; when the spring (12) is in a normal state, the bottom of the stirring paddle (11) is clearance-matched with the discharge tray (5); A heating block (13) is arranged inside the box body (1), a through hole (14) is opened on the side wall of the box body (1), and the box body (1) is sealedly connected to the vacuum pump pipeline through the through hole (14).

9. The method for preparing ultra-high purity germanium dioxide according to claim 8, characterized in that: A support plate (41) is fixedly sleeved on the upper side of the rotating column (4), and a baffle (51) is fixedly arranged on the edge of the discharge tray (5).

10. The method for preparing ultra-high purity germanium dioxide according to claim 8, characterized in that: A plurality of support columns (15) are evenly arranged at the bottom of the box body (1), and the height of the plurality of support columns (15) is greater than the height of the first motor (6).

Images