Preparation method of high-purity germanium dioxide
By first acidifying the germanium tetrafluoride hydrolysate and adding alkali to convert it into germanium acid salt, combined with the chlorination and distillation method, the problems of large hydrolysis loss of germanium tetrachloride and low yield in the prior art were solved, and the preparation of germanium dioxide with high purity and high yield was achieved, which significantly improved the purity and yield of the product.
Patent Information
- Application Number
- CN202411695574.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-02-28
AI Technical Summary
In the prior art, when preparing high-purity germanium dioxide, the hydrolysis loss of germanium tetrachloride is large, the yield is low, and the product purity is insufficient, which affects the research and application of the detector.
The germanium tetrafluoride hydrolysate is first acidified, and then the alkali is added to convert all the germanium elements into germanium salts, and high-purity germanium dioxide is obtained by chlorination and distillation. This method removes fluorine when acidizing the hydrolysate, reduces the loss of hydrolysis of germanium tetrachloride and improves the yield and purity of germanium dioxide.
The yield of germanium dioxide was improved from about 70% to 85%, and the purity of the product was increased to >99.99%, which was one order of magnitude higher than the purity of germanium dioxide prepared by the original chlorination distillation method and the ammonia water neutralization method.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of preparation and research of detectors, and in particular to a method for preparing high-purity germanium dioxide. Background Art
[0002] Germanium is a Group IV element in the periodic table and is a metal element. Germanium is widely used in semiconductor materials, optoelectronic materials, thermoelectric materials, and infrared optical materials. At present, the industrial methods for preparing metallic germanium at home and abroad are almost the same, which is to use hydrogen to reduce germanium dioxide. Therefore, germanium dioxide is the most important raw material for preparing metallic germanium.
[0003] In the preparation and research of detectors, the isotope of germanium, germanium-76, is used. Germanium tetrafluoride is the working fluid for the separation of germanium isotopes. Germanium tetrafluoride-76 can be obtained by separating natural germanium tetrafluoride. Therefore, to obtain the single substance of germanium-76, it is first necessary to prepare germanium dioxide-76 using germanium tetrafluoride-76 as the raw material, and then reduce germanium dioxide-76 with hydrogen. Since the reduction of germanium dioxide with hydrogen to prepare metallic germanium is a very mature process, the process of converting germanium tetrafluoride to germanium dioxide has become a key technology in this research field. The state, purity and other properties of its products directly affect the research and application of detectors and are of great significance. Summary of the invention
[0004] In view of this, an embodiment of the present application provides a method for preparing high-purity germanium dioxide, which uses germanium tetrafluoride as a raw material to prepare high-purity and high-yield germanium dioxide.
[0005] The present application provides the following technical solution: a method for preparing high-purity germanium dioxide, comprising the following steps: S1, hydrolyzing germanium tetrafluoride gas, adding dilute sulfuric acid to the generated germanium tetrafluoride hydrolyzate to generate germanium sulfate solution; S2, adding sodium hydroxide solution to the germanium sulfate solution, stirring, to generate a sodium germanate solution; S3. Add concentrated hydrochloric acid to the sodium germanate solution to carry out chlorination distillation. When the distillation temperature of the fraction is ≥110°C, stop the distillation to obtain a germanium tetrachloride fraction, cool it and hydrolyze it, and then filter and dry it to obtain high-purity germanium dioxide.
[0006] According to an embodiment of the present application, in S1, germanium tetrafluoride gas is subjected to a hydrolysis reaction at 10-20°C.
[0007] According to an embodiment of the present application, S1 also includes: adding dilute sulfuric acid to the generated germanium tetrafluoride hydrolyzate to react to generate a germanium sulfate solution, heating and continuing the reaction for 20-30 minutes, and removing the hydrogen fluoride gas generated during the reaction.
[0008] According to an embodiment of the present application, in S1, the mass ratio of germanium tetrafluoride gas to dilute sulfuric acid is 1:1.35-1.50.
[0009] According to an embodiment of the present application, in S2, sodium hydroxide solution is slowly added dropwise to the germanium sulfate solution while stirring, and the reaction temperature is controlled not to exceed 20° C. After the addition is completed, stirring is continued for 10 to 20 minutes.
[0010] According to an embodiment of the present application, in S2, the mass percentage concentration of the sodium hydroxide solution is 28.5-29.5%.
[0011] According to an embodiment of the present application, in S3, concentrated hydrochloric acid is added to the sodium germanate solution, the oil bath temperature is controlled to 115-120°C, chlorination distillation is performed, and the distillation rate of the fraction is controlled at 1-2 drops / second by the oil bath temperature.
[0012] According to an embodiment of the present application, in S3, a germanium tetrachloride fraction having a distillation temperature between 105 and 110° C. is collected, and the distillation is stopped when the distillation temperature of the germanium tetrachloride fraction is ≥110° C.
[0013] According to an embodiment of the present application, in S3, the mass ratio of sodium germanate to concentrated hydrochloric acid is 1:13-14.
[0014] According to an embodiment of the present application, in S3, the mass percentage concentration of the concentrated hydrochloric acid is 37-38%.
[0015] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification include at least: the embodiment of the present invention adopts a method of first acidifying the germanium tetrafluoride hydrolyzate, and then adding alkali to convert all the germanium elements into germanate, which effectively reduces the loss of germanium tetrachloride hydrolysis, improves the yield of germanium tetrachloride distillation, and thus improves the yield of germanium dioxide, and increases the yield of germanium dioxide prepared by the original chlorination distillation method from about 70% to 85%. The method removes the fluorine element when acidifying the hydrolyzate, and no other volatile substances are introduced during the reaction process, and other impurities will not be introduced during the distillation of germanium tetrachloride, which effectively improves the purity of the germanium dioxide product, and the product purity is greater than 99.99%, which is an order of magnitude higher than the purity of germanium dioxide prepared by the original chlorination distillation method and the ammonia neutralization method. The germanium dioxide product obtained by the method of the present invention is a white crystalline solid, which is visually whiter than the product prepared by the ammonia neutralization method, and is light in weight, and the bulk density is 1 / 4 to 1 / 5 of the product prepared by the ammonia neutralization method. The product has a large specific surface area, which is more conducive to the subsequent hydrogenation reduction step. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0017] Figure 1 Schematic diagram of hydrolysis and acidification of germanium tetrafluoride in an embodiment of the present invention; Figure 2 is a schematic diagram of the conversion of germanate in an embodiment of the present invention; Figure 3 Schematic diagram of chlorination distillation in an embodiment of the present invention; Figure 4 is a reaction flow chart of a method for preparing high-purity germanium dioxide according to an embodiment of the present invention; Among them, 1- low temperature constant temperature bath, 2- ultrapure water, 3- dilute sulfuric acid, 4- alkali solution, 5- germanium sulfate solution, 6- sodium hydroxide solution, 7- germanium hydroxide solid, 8- temperature controller, 9- concentrated hydrochloric acid, 10- oil bath, 11- germanium tetrachloride fraction. DETAILED DESCRIPTION
[0018] The embodiments of the present application are described in detail below with reference to the accompanying drawings.
[0019] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.
[0020] like Figure 1-Figure 4 As shown, the embodiment of the present invention provides a method for preparing high-purity germanium dioxide, comprising the following steps: S1, hydrolyzing germanium tetrafluoride gas, adding dilute sulfuric acid to the generated germanium tetrafluoride hydrolyzate to generate germanium sulfate solution; S2, adding sodium hydroxide solution to the germanium sulfate solution, stirring, to generate a sodium germanate solution; S3. Add concentrated hydrochloric acid to the sodium germanate solution to carry out chlorination distillation. When the distillation temperature of the fraction is ≥110°C, stop the distillation to obtain a germanium tetrachloride fraction, cool it and hydrolyze it, and then filter and dry it to obtain high-purity germanium dioxide.
[0021] The embodiment of the present invention relates to a new process for preparing high-purity germanium dioxide from germanium tetrafluoride as a raw material under alkaline conditions. The whole reaction process is as follows: Figure 4 As shown, the preparation method specifically comprises the following steps: Step 1: Figure 1 As shown, the hydrolysis and acidification process of germanium tetrafluoride.
[0022] Add a certain amount of ultrapure water 2 to the polytetrafluoroethylene reactor, and place the reactor in a low-temperature thermostatic bath 1, control the temperature at 10~20℃, slowly introduce germanium tetrafluoride gas under stirring, and continue stirring for 20~30min after the gas is introduced to ensure that the gas dissolves and reacts completely. Then slowly add a certain amount of dilute sulfuric acid 3 to the germanium tetrafluoride hydrolyzate to convert all the germanium tetrafluoride hydrolysis products into germanium sulfate solution, heat for a period of time to remove the generated hydrogen fluoride gas, and the hydrogen fluoride gas is treated with alkali solution 4 and discharged to meet the standards. The specific reaction process is as follows: 3GeF4+2H2O=GeO2+2H2GeF6 GeO2+2H2SO4=Ge(SO4)2+2H2O 2H2GeF6+2H2SO4=Ge(SO4)2+6HF↑ Step 2: Figure 2 As shown, the process of converting germanate by adding alkali.
[0023] Slowly add a certain concentration of sodium hydroxide solution 6 to the germanium sulfate solution 5, stirring while adding, controlling the dropping speed, and monitoring the temperature of the reaction solution at the same time, and controlling it not to exceed 20°C through the temperature controller 8. After the addition is completed, continue stirring for 10-20 minutes to convert all the germanium elements into sodium germanate. The reaction process is as follows: Ge(SO4)2+6NaOH=Na2GeO3+2Na2SO4+3H2O The reason why sodium hydroxide is used to convert germanium sulfate into sodium germanate in this process is that the oxyacid salts, chlorides, bromides and other substances of Ge (IV) cannot exist stably in aqueous solution, and will undergo violent hydrolysis to generate germanium hydroxide solid 7. This substance is solid and cannot be distilled out during the chlorination distillation process, resulting in loss of germanium element and reduced yield. Therefore, the embodiment of the present invention utilizes the amphoteric properties of germanium hydroxide and can use alkali to convert it into germanate. The reaction process is as follows: Ge(SO4)2+4H2O⇋Ge(OH)4+2H2SO4 Ge(OH)4+2NaOH=Na2GeO3+3H2O Step 3: Figure 3 As shown, the chlorination distillation and hydrolysis process of germanium tetrachloride.
[0024] Concentrated hydrochloric acid 9 is added to the reaction kettle in proportion, and a certain amount of concentrated hydrochloric acid is also added to the dropping funnel. The temperature of the oil bath 10 is adjusted to 115-120°C, and chlorination distillation is started. The distillation rate of the fraction is controlled at 1-2 drops / second by the oil bath temperature, and the fraction between 105-110°C is collected. When the distillation rate of the fraction slows down, a small amount of concentrated hydrochloric acid is added, and distillation is continued for a period of time. When the distillation temperature of the fraction is ≥110°C, the distillation is stopped. A certain amount of ultrapure water is added to the germanium tetrachloride fraction 11 under cooling and stirring conditions to hydrolyze it, and after precipitation, it is filtered and dried.
[0025] When hydrochloric acid is added to the reactor, sodium germanate reacts with hydrochloric acid to regenerate germanium tetrachloride. Germanium tetrachloride is distilled out in time with heating, which reduces the degree of hydrolysis, increases the amount of distilled germanium tetrachloride, and significantly improves the yield of germanium dioxide. In addition, due to the discharge of hydrogen fluoride during the acidification process of the germanium tetrafluoride hydrolyzate, the interference of fluoride ions is removed. During the distillation process, sodium sulfate, sodium chloride, etc. in the solution are all high-boiling salts and will not be distilled out during the distillation process. They always remain in the solution, effectively avoiding the contamination of the distillate germanium tetrachloride and improving the purity of the product. The specific reaction process is as follows: Na2GeO3+6HCl=2NaCl+GeCl4+3H2O GeCl4+2H2O=GeO2↓+4HCl The embodiment of the present invention adopts a method of first acidifying the germanium tetrafluoride hydrolyzate, and then adding alkali to convert all the germanium elements into germanate, which effectively reduces the loss of germanium tetrachloride hydrolysis, improves the yield of germanium tetrachloride distillation, and thus improves the yield of germanium dioxide, and increases the yield of germanium dioxide prepared by the original chlorination distillation method from about 70% to 85%. The method removes the fluorine element when the hydrolyzate is acidified, and no other volatile substances are introduced during the reaction process. No other impurities are introduced during the distillation of germanium tetrachloride, which effectively improves the purity of the germanium dioxide product, and the product purity is greater than 99.99%, which is an order of magnitude higher than the purity of germanium dioxide prepared by the original chlorination distillation method and the ammonia neutralization method. The germanium dioxide product obtained by the method of the present invention is a white crystalline solid, which is visually whiter than the product prepared by the ammonia neutralization method, and is light in weight, and the bulk density is 1 / 4 to 1 / 5 of the product prepared by the ammonia neutralization method. The product has a large specific surface area, which is more conducive to the subsequent hydrogenation reduction step.
[0026] The preparation method of the present invention is further described below using specific examples.
[0027] Embodiment 1: The preparation method of the present embodiment comprises: adding 78.8g of ultrapure water to a 500ml polytetrafluoroethylene reactor, placing the reactor in a low temperature tank, controlling the temperature at 10°C, starting stirring, slowly introducing 11.7g of germanium tetrafluoride gas, continuing stirring for 20min after the introduction is completed, slowly dripping 16.85g of sulfuric acid, heating for 20min to remove the generated hydrogen fluoride gas. Dissolve 20g of sodium hydroxide in 50g of water to form a 28.6% sodium hydroxide solution, slowly drip it into the reactor with a dropping funnel, stir while adding, and continue stirring for 15min after the addition is completed. Add 184g of 37.5% concentrated hydrochloric acid to the reactor, add 20g of concentrated hydrochloric acid to the dropping funnel, adjust the oil bath temperature to 115℃ to start chlorination distillation, collect the fraction between 105 and 110℃, add 10g of concentrated hydrochloric acid when the fraction distillation speed slows down, continue distillation for a while, stop heating when the fraction distillation temperature is ≥110℃, and obtain 15.3g of fraction, with a chlorination distillation yield of 90.6%. Add 100g of ultrapure water to the germanium tetrachloride fraction under cooling and stirring conditions to hydrolyze, filter and dry after leaving overnight, and obtain 7.10g of white germanium dioxide crystals with an overall yield of 86.1%.
[0028] Embodiment 2: The preparation method of the present embodiment comprises: adding 82g of ultrapure water to a 1000ml polytetrafluoroethylene reactor, placing the reactor in a low temperature tank, controlling the temperature at 15°C, turning on stirring, slowly introducing 23.2g of germanium tetrafluoride gas, continuing stirring for 30min after the introduction is completed, slowly dripping 31g of sulfuric acid, heating for 30min to remove the generated hydrogen fluoride gas. Dissolve 41.1g of sodium hydroxide in 100g of water to prepare a 29.1% sodium hydroxide solution, slowly drip it into the reactor with a dropping funnel, stir while dripping, and continue stirring for 20min after the addition is completed. Add 364g of 37.5% concentrated hydrochloric acid to the reactor, add 20g of concentrated hydrochloric acid to the dropping funnel, adjust the oil bath temperature to 120℃ to start chlorination distillation, collect the fraction between 105 and 110℃, add 15g of concentrated hydrochloric acid when the fraction distillation speed slows down, continue distillation for a while, stop heating when the fraction distillation temperature is ≥110℃, and obtain 29.6g of fraction, with a chlorination distillation yield of 88.5%. Add 195g of ultrapure water to the germanium tetrachloride fraction under cooling and stirring conditions to hydrolyze, filter and dry after leaving overnight, and obtain 14.0g of white germanium dioxide crystals with an overall yield of 85.4%.
[0029] The product qualities in the above-mentioned Embodiment 1 and Embodiment 2 of the present invention can both reach the following qualities, as specifically shown in Table 1 and Table 2.
[0030] Table 1 Test results of product of Example 1
[0031] Table 2 Example 2 product test results
[0032] The products of Example 1 and Example 2 were tested by XRD, and the products contained GeO2 (hexagonal system, ≥99%), with a crystallinity of ≥99%, and the total amount of 18 impurity elements was <0.006%, and the purity of the product was significantly improved.
[0033] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.
Claims
1. A method for preparing high-purity germanium dioxide, characterized in that: The following steps are involved: S1, hydrolyzing germanium tetrafluoride gas, adding dilute sulfuric acid to the generated germanium tetrafluoride hydrolyzate to generate germanium sulfate solution; S2, adding sodium hydroxide solution to the germanium sulfate solution, stirring, to generate a sodium germanate solution; S3. Add concentrated hydrochloric acid to the sodium germanate solution to carry out chlorination distillation. When the distillation temperature of the fraction is ≥110°C, stop the distillation to obtain a germanium tetrachloride fraction, cool it and hydrolyze it, and then filter and dry it to obtain high-purity germanium dioxide.
2. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S1, germanium tetrafluoride gas is subjected to a hydrolysis reaction at 10-20°C.
3. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: S1 also includes: adding dilute sulfuric acid to the generated germanium tetrafluoride hydrolyzate to react to generate a germanium sulfate solution, heating to continue the reaction for 20-30 minutes, and removing the hydrogen fluoride gas generated during the reaction.
4. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S1, the mass ratio of germanium tetrafluoride gas to dilute sulfuric acid is 1:1.35-1.
50.
5. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S2, slowly add sodium hydroxide solution to the germanium sulfate solution while stirring, and control the reaction temperature not to exceed 20°C. After the addition is completed, continue stirring for 10 to 20 minutes.
6. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S2, the mass percentage concentration of the sodium hydroxide solution is 28.5-29.5%.
7. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S3, concentrated hydrochloric acid is added to the sodium germanate solution, and the oil bath temperature is controlled to 115-120° C. to perform chlorination distillation, and the distillation rate of the fraction is controlled at 1-2 drops / second by the oil bath temperature.
8. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S3, the germanium tetrachloride fraction with a distillation temperature between 105 and 110° C. is collected, and the distillation is stopped when the distillation temperature of the germanium tetrachloride fraction is ≥110° C.
9. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S3, the mass ratio of sodium germanate to concentrated hydrochloric acid is 1:13-14.
10. The method for preparing high-purity germanium dioxide according to claim 1, characterized in that: In S3, the mass percentage concentration of the concentrated hydrochloric acid is 37-38%.
Citation Information
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