A method and dedicated apparatus for preparing highly dispersible spherical germanium dioxide

Abstract

This invention relates to the field of germanium oxide preparation technology, specifically to a method and dedicated apparatus for preparing highly dispersed spherical germanium dioxide. The preparation method includes: using a carrier gas to carry germanium tetrachloride vapor into a reactor, and also introducing water vapor into the reactor; controlling the temperature to allow the germanium tetrachloride vapor and water vapor to undergo a chemical vapor deposition reaction to generate germanium dioxide. The dedicated apparatus includes: a carrier gas supply device, a germanium tetrachloride evaporator, a fluidized bed chemical vapor deposition reactor, and a water vapor generator. This invention employs fluidized bed chemical vapor deposition, achieving stable preparation of highly dispersed spherical germanium dioxide through precise control of chemical vapor deposition process parameters, overcoming the technical difficulties of severe product agglomeration, uneven morphology, and low purity in existing germanium oxide preparation methods.

Description

Technical Field

[0001] This invention relates to the field of germanium oxide preparation technology, specifically to a method and dedicated apparatus for preparing highly dispersed spherical germanium dioxide using fluidized bed chemical vapor deposition. Background Technology

[0002] Germanium dioxide is an important semiconductor material with excellent optical transmittance, electron mobility, and chemical stability, making it promising for applications in optical glass, catalyst supports, lithium-ion battery anode materials, and gas sensors. Its performance is highly dependent on particle size, morphology, and dispersibility. Highly dispersed germanium oxide particles provide a larger specific surface area and more active surface sites, significantly improving its performance in these applications.

[0003] Methods for preparing germanium oxide particles mainly include hydrolysis precipitation, hydrothermal methods, microemulsion methods, vapor phase growth methods, and electrodeposition methods. However, these methods have some limitations.

[0004] Hydrolysis-precipitation method: CN119240780A discloses a precipitation method for preparing ultra-high purity germanium dioxide. This method involves grinding germanium ingots into germanium powder, chlorinating the powder with high-purity chlorine gas to germanium tetrachloride, purifying it by distillation, adding ultrapure water, stirring thoroughly, allowing it to stand, and filtering to obtain germanium dioxide precipitate. The germanium dioxide precipitate is then washed, dried, and calcined to obtain ultra-high purity germanium dioxide with a purity of 7N or higher. This method yields germanium dioxide with high purity and high yield, and a chlorine content below 0.003%. However, the process is complex, generates a large amount of toxic waste gas, and the product has uneven morphology, poor dispersibility, severe agglomeration, and poor control over particle morphology.

[0005] CN119528208A discloses a precipitation method for preparing high-purity germanium dioxide. Germanium tetrafluoride is repeatedly purified by distillation, then hydrolyzed. Dilute sulfuric acid is added to the hydrolysate to generate germanium sulfate solution; sodium hydroxide solution is then added to generate sodium germanate solution; concentrated hydrochloric acid is added to the sodium germanate solution, followed by chlorination distillation to obtain germanium tetrachloride fraction. After cooling, the fraction is hydrolyzed, filtered, and dried to obtain high-purity germanium dioxide. This method yields high-purity germanium dioxide, but the product exhibits poor dispersibility, severe agglomeration, and is difficult to control, and the process route is cumbersome.

[0006] Hydrothermal Method: CN121573705A discloses a tetragonal germanium dioxide and its hydrothermal synthesis method. This method uses hexagonal germanium dioxide as raw material, first calcining the raw material at 500-600℃ for 4-8 hours, then carrying out a hydrothermal reaction in an acidic aqueous solution. The reaction temperature is controlled at 120℃-240℃, the reaction time at 24-48 hours, and the pH value at 1-3 to achieve the transformation from hexagonal to tetragonal crystals. The germanium oxide prepared by this method has a relatively regular morphology and few impurities. When used for the catalytic synthesis of PET, the product performance is slightly better than that produced using hexagonal germanium dioxide. However, the product produced by this method has poor dispersibility and severe agglomeration.

[0007] CN104310461A discloses a hydrothermal method for preparing germanium oxide. The method involves adding an appropriate amount of ethylenediamine to a cobalt nitrate solution containing a certain amount of germanium oxide, and reacting the mixture under hydrothermal conditions for 1-5 days. After the reaction, an initial product is obtained, which is then washed multiple times with ethanol and water and dried to obtain the germanium oxide product. This method offers good control over the product morphology, and the prepared germanium oxide nanowires exhibit good fluorescence activity and a large specific surface area. However, impurities are introduced during the reaction, leading to a decrease in product purity.

[0008] Microemulsion method: Michael H. Huang first mixed 1.56 g Triton X-100 (4-octylphenol polyethoxylate), 5.60 mL cyclohexane (99.9%), 1.48 mL n-hexanol (98.9%), and 0.60 mL hydrochloric acid (37%). The pH of the solution was adjusted to 1.0 ± 0.1. The mixture was stirred for about 1 hour until the solution became clear. Then, under a nitrogen atmosphere, 0.50 mL of 0.56 M germanium(IV) ethoxylate solution (99.995%) was added dropwise using a 1.0 mL syringe. The final reagent molar ratio was 1.0:118.9:0.2:8.9:52.3:185.0 Ge(OEt)4 / H2O / HCl / TX-100 / n-hexanol / cyclohexane. The mixture was stirred vigorously at room temperature for 3 hours, and the resulting particles were immediately centrifuged at 7000 r / min for 7 minutes and then redispersed in 2-propanol in an ultrasonic bath. The centrifugation process was repeated six times to completely remove surfactants and unreacted reagents. Although this method can obtain germanium oxide particles with good monodispersity, the process is complex, and the reaction introduces organic phase impurities, leading to a decrease in product purity.

[0009] Vapor phase growth method: Peng Mingfa used germanium powder as the germanium source and Au film as the catalyst. Under a vacuum of 10 Pa and an Ar atmosphere, he controlled the reaction temperature in the central region of a tube furnace at 930℃ and the deposition temperature between 475℃ and 580℃ to prepare hexagonal GeO2 nanowires with high density, lengths of tens of micrometers, and diameters of approximately 50-100 nm. This method produces well-dispersed germanium oxide products. However, the large number of high aspect ratio nanowires are prone to entanglement and agglomeration during collection and transfer. Furthermore, the use of Au film as a catalyst may introduce impurities, affecting product purity.

[0010] Electrodeposition: Youcef A. Bioud employed a traditional three-electrode, single-chamber electrochemical electrolytic cell, using a platinum sheet as the counter electrode, a saturated calomel electrode as the reference electrode, and a 10% GeCl4 solution (GeCl4:H2O2, volume ratio 1:9) as the electrolyte. Hexagonal GeO2 nanoparticles of different morphologies and sizes were prepared on Ge wafers via constant potential deposition using this method. This method is simple to operate and offers strong control over the product morphology; however, the deposition process may be uneven, and the product may contain oxygen vacancy defects. While these defects contribute to blue and green light emission, excessive defects can also lead to unstable optical properties of the material.

[0011] The preparation methods for germanium dioxide still need further improvement. Summary of the Invention

[0012] To address at least one of the aforementioned problems in the prior art, this invention provides a method for preparing highly dispersed germanium dioxide. The method employs fluidized bed chemical vapor deposition (CVD) and achieves stable preparation of highly dispersed spherical germanium dioxide through precise control of CVD process parameters. This overcomes the technical difficulties in existing germanium dioxide preparation methods, such as severe product agglomeration, uneven morphology, and low purity.

[0013] A method for preparing highly dispersible spherical germanium dioxide includes:

[0014] 1) The fluidized bed chemical vapor deposition reactor is purged with carrier gas to fill the reactor with the carrier gas;

[0015] 2) Germanium tetrachloride is evaporated and vaporized at 100-145℃, and the carrier gas carries the germanium tetrachloride vapor into the reactor; deionized water is vaporized, and the water vapor enters the reactor; wherein, the flow rate of the carrier gas is 0.1-1 L / min; and the flow rate of the water vapor is 0.1-5.4 L / min.

[0016] The temperature of the reactor is controlled so that the germanium tetrachloride vapor and the water vapor undergo a chemical vapor deposition reaction at 300-750°C to generate germanium dioxide.

[0017] 3) Cool down to obtain highly dispersed spherical germanium dioxide.

[0018] This invention employs fluidized bed chemical vapor deposition (CVD) to prepare highly dispersible germanium dioxide for the first time, with an average particle size of 5-20 μm, by controlling the evaporation temperature of germanium tetrachloride, the carrier gas flow rate, the water vapor flow rate, and the CVD reaction temperature. The germanium dioxide particles prepared by this method exhibit uniform morphology, no agglomeration, high dispersibility, and high purity.

[0019] The method of the present invention first purges the reactor with carrier gas, which can fill the reactor with carrier gas and remove impurities in the reactor, thereby improving the purity of the product germanium dioxide.

[0020] In some embodiments, the reactor may be heated to the reaction temperature before a carrier gas is introduced for purging.

[0021] According to embodiments of the present invention, the vaporization temperature of germanium tetrachloride is 100-145°C, preferably 100-140°C, and more preferably 110-130°C. Specifically, examples include 100°C, 110°C, 120°C, 130°C, or 140°C. Studies have found that when the vaporization temperature of germanium tetrachloride is too high (e.g., equal to or higher than 150°C), the generated germanium dioxide is prone to agglomeration, which is detrimental to the preparation of highly dispersed germanium dioxide. If the temperature is too low, germanium tetrachloride is difficult to vaporize.

[0022] According to embodiments of the present invention, the carrier gas flow rate is 0.1-1 L / min, for example, 0.1 L / min, 0.2 L / min, 0.3 L / min, 0.4 L / min, 0.5 L / min, 0.6 L / min, 0.7 L / min, 0.8 L / min, 0.9 L / min, or 1 L / min. Studies have found that when the carrier gas flow rate is too low, it is difficult to uniformly introduce the vaporized germanium tetrachloride into the reactor. Simultaneously, the diffusion kinetics of germanium tetrachloride are insufficient, resulting in uneven mixing of reactants and uneven concentration distribution of reactants within the system. The reaction occurs in localized areas with higher concentrations of gaseous germanium tetrachloride, leading to product agglomeration. When the carrier gas flow rate is too high, the product dispersibility is not significantly improved; instead, defects appear in the particle surface morphology.

[0023] According to embodiments of the present invention, the flow rate of the water vapor is 0.1-5.4 L / min, preferably 0.18-1.8 L / min. Specific examples include 0.1 L / min, 0.126 L / min, 0.18 L / min, 0.54 L / min, 0.9 L / min, 1 L / min, 1.26 L / min, 1.8 L / min, 2 L / min, 3 L / min, 3.6 L / min, 4 L / min, 5 L / min, or 5.4 L / min.

[0024] This invention has found that the flow rate of water vapor affects the dispersibility of germanium dioxide; within a certain flow rate range, the dispersibility of germanium dioxide is improved. If the flow rate is too low (e.g., equal to or below 0.05 L / min), the water vapor concentration in the reactor is too low, resulting in fewer nuclei, product adhesion, and poor product dispersibility. If the flow rate is too high, the gas flow rate in the system is too high, and a large amount of reactants are discharged from the reactor before reacting, resulting in extremely low reaction efficiency.

[0025] According to embodiments of the present invention, the temperature of the chemical vapor deposition reaction is 300-750°C, preferably 300-700°C. Specifically, examples include 300°C, 350°C, 400°C, 500°C, 600°C, or 700°C. Studies have found that if the temperature is too low, sufficient activation energy cannot be provided, making the reaction difficult to occur; if the temperature is too high (e.g., equal to or above 800°C), interparticle collisions become more intense, leading to sintering and poor product dispersibility.

[0026] According to an embodiment of the present invention, the carrier gas is nitrogen (N2).

[0027] According to an embodiment of the present invention, the cooling can be reduced to room temperature. During cooling, the carrier gas can be kept circulating, and a highly dispersible germanium dioxide product is obtained after cooling.

[0028] Based on common knowledge in the field, the above-mentioned preferred conditions can be combined with each other to obtain various preferred embodiments of the present invention.

[0029] The present invention also includes germanium dioxide prepared by the above method.

[0030] According to an embodiment of the present invention, the germanium dioxide purity can reach 99.9%.

[0031] According to an embodiment of the present invention, the average particle size of the germanium dioxide is 5-20 μm.

[0032] According to an embodiment of the present invention, the germanium dioxide has a spherical morphology with good dispersibility.

[0033] According to an embodiment of the present invention, the germanium dioxide exhibits good dispersibility, high crystallinity, and narrow particle size distribution, which can meet the application requirements of conventional precision machining and catalysis fields.

[0034] The present invention also includes the application of the aforementioned germanium dioxide in precision machining and catalysis.

[0035] The present invention also provides a dedicated apparatus for preparing germanium dioxide by fluidized bed chemical vapor deposition, which is used to prepare highly dispersed spherical germanium dioxide by the above method.

[0036] Specifically, the dedicated device includes:

[0037] Carrier gas supply equipment, used to provide carrier gas;

[0038] Germanium tetrachloride evaporator is used to vaporize germanium tetrachloride into germanium tetrachloride vapor;

[0039] Fluidized bed chemical vapor deposition reactor, used for chemical vapor deposition reactions;

[0040] The carrier gas supply device is connected to the inlet of the germanium tetrachloride evaporator, and the outlet of the germanium tetrachloride evaporator is connected to the inlet at the bottom of the reactor, so that germanium tetrachloride vapor enters the interior of the reactor through the bottom of the reactor under the carrier gas.

[0041] A steam generator is used to vaporize deionized water into steam; the outlet of the steam generator is connected to the inlet at the bottom of the reactor so that the steam enters the interior of the reactor through the bottom of the reactor.

[0042] This invention is the first to use fluidized bed chemical vapor deposition (FCVD) to prepare germanium dioxide powder. By optimizing the process and precisely controlling the reaction parameters and mechanism, it solves the problems of severe product agglomeration and uneven morphology in existing preparation methods. Furthermore, the process is stable, simple, and fast. The germanium dioxide prepared by this method has the advantages of high dispersibility, good sphericity, and high purity. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the reaction apparatus according to an embodiment of the present invention.

[0044] Figure 2 The image shows the morphology of germanium dioxide prepared in Example 1 using scanning electron microscopy (SEM).

[0045] Figure 3 The image shows the morphology of germanium dioxide prepared in Example 2 using scanning electron microscopy (SEM).

[0046] Figure 4 The image shows the morphology of germanium dioxide prepared in Example 3 using scanning electron microscopy (SEM).

[0047] Figure 5 The image shows the morphology of germanium dioxide prepared in Example 4 using scanning electron microscopy (SEM).

[0048] Figure 6 The image shows the morphology of germanium dioxide prepared in Example 5 using scanning electron microscopy (SEM).

[0049] Figure 7 The image shows the morphology of germanium dioxide prepared in Example 6 using scanning electron microscopy (SEM).

[0050] Figure 8The image shows the morphology of germanium dioxide prepared in Example 7 using scanning electron microscopy (SEM).

[0051] Figure 9 The image shows the morphology of germanium dioxide prepared in Example 8 using scanning electron microscopy (SEM).

[0052] Figure 10 The image shows the morphology of germanium dioxide prepared in Example 9 using scanning electron microscopy (SEM).

[0053] Figure 11 The image shows the morphology of germanium dioxide prepared in Comparative Example 1 as detected by scanning electron microscopy (SEM).

[0054] Figure 12 The image shows the morphology of germanium dioxide prepared in Comparative Example 2 as detected by scanning electron microscopy (SEM).

[0055] Figure 13 The image shows the morphology of germanium dioxide prepared in Comparative Example 3 as detected by scanning electron microscopy (SEM).

[0056] Figure 14 The image shows the morphology of germanium dioxide prepared in Comparative Example 4 as detected by scanning electron microscopy (SEM). Detailed Implementation

[0057] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0058] like Figure 1 As shown, this embodiment of the invention provides a dedicated apparatus for preparing germanium dioxide using fluidized bed chemical vapor deposition (CVD), used to prepare highly dispersed spherical germanium dioxide by the above-mentioned method. Specifically, the dedicated apparatus includes: a carrier gas supply device 100 for providing a carrier gas; a germanium tetrachloride evaporator 200 for vaporizing germanium tetrachloride into germanium tetrachloride vapor; and a fluidized bed CVD reactor 300 for conducting the CVD reaction. The carrier gas supply device 100 is connected to the inlet of the germanium tetrachloride evaporator 200, and the outlet of the germanium tetrachloride evaporator 200 is connected to the inlet at the bottom of the reactor 300, so that germanium tetrachloride vapor enters the interior of the reactor 300 via the bottom of the reactor under the carrier gas. A steam generator 400 is used for vaporizing deionized water into steam; the outlet of the steam generator 400 is connected to the inlet at the bottom of the reactor 300, so that steam enters the interior of the reactor 300 via the bottom of the reactor.

[0059] Furthermore, the reactor 300 also includes a heater 310 for supplying heat to the reactor 300.

[0060] In some specific embodiments, the heater 310 is a heating furnace, which is disposed on the outer wall of the reactor 300.

[0061] Furthermore, the reactor 300 also includes a porous gas distribution plate 320 disposed at the bottom of the reactor 300 for uniformly distributing the gas (carrier gas, germanium tetrachloride vapor and water vapor) to ensure stable fluidization.

[0062] Figure 1 The 330 in the text represents the reaction product, germanium dioxide particles.

[0063] Furthermore, the device also includes a product collector 500 for collecting germanium dioxide particles.

[0064] In some embodiments, the product collector 500 is connected to the top outlet of the reactor 300, and the reaction product germanium dioxide in the reactor 300 enters the product collector 500 under the carrier gas and is collected.

[0065] Furthermore, the apparatus also includes a tail gas absorption device 600, connected to the top outlet of the product collector 500, for absorbing tail gas. The tail gas mainly includes carrier gas, water vapor, byproduct HCl, and unreacted germanium tetrachloride.

[0066] In some embodiments, the carrier gas is nitrogen.

[0067] In some embodiments, the absorbent of the exhaust gas absorption device 600 is a sodium hydroxide solution.

[0068] In some embodiments, the reactor described in this invention may be a reactor commonly used in fluidized bed chemical vapor deposition.

[0069] It is understood that the components of the device described in this invention can be connected by pipes, and valves can be installed on the pipes to control the material flow rate.

[0070] In application, the apparatus of this invention first introduces a carrier gas into the reactor to purge it, removing impurities and filling the reactor with the carrier gas. Then, the germanium tetrachloride evaporator is turned on, allowing germanium tetrachloride vapor to enter the reactor from the bottom under the carrier gas.

[0071] The germanium tetrachloride evaporator has a heating function, which can vaporize liquid germanium tetrachloride into germanium tetrachloride vapor. As a preferred embodiment, the vaporization temperature of germanium tetrachloride is 100-140℃.

[0072] Specifically, the carrier gas output from the carrier gas supply device 100 is introduced into the germanium tetrachloride evaporator 200. The carrier gas carrying germanium tetrachloride vapor is introduced through a pipeline into the gas inlet located at the bottom of the reactor 300, thereby allowing the germanium tetrachloride vapor to enter the interior (reaction zone) of the reactor from the bottom upwards. The water vapor output from the steam generator (400) is introduced through a pipeline into the gas inlet located at the bottom of the reactor (300), thereby allowing the water vapor to enter the interior (reaction zone) of the reactor from the bottom upwards.

[0073] Unless otherwise specified, the following embodiments adopt Figure 1 The apparatus shown is used for preparation.

[0074] In the following examples, nitrogen was used as the carrier gas.

[0075] Example 1

[0076] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide: First, a fluidized bed chemical vapor deposition reactor is heated to 500°C, then a carrier gas is introduced at a rate of 0.3 L / min and purged for 30 min to remove other gases. Germanium tetrachloride is placed in a germanium tetrachloride evaporator, and the vaporization temperature is set to 110°C to vaporize the germanium tetrachloride into germanium tetrachloride vapor. The carrier gas is introduced into the germanium tetrachloride evaporator at a flow rate of 0.3 L / min, allowing the carrier gas to carry the germanium tetrachloride vapor into the reactor from the bottom. Deionized water is placed in a steam generator, and the vaporization temperature is set to 125°C to vaporize the deionized water into water vapor. The water vapor flow rate is controlled at 1.8 L / min, and the water vapor is introduced into the reactor from the bottom. The reactor temperature is controlled so that the germanium tetrachloride vapor and the water vapor undergo a chemical vapor deposition reaction at 500°C to generate germanium dioxide particles. The reaction time is 70 min. The particles are collected to obtain well-dispersed germanium dioxide powder.

[0077] The average particle size of germanium dioxide prepared in this embodiment was found to be 9 μm.

[0078] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 2 As shown. From Figure 2 It is evident that germanium dioxide consists of individual spherical particles, exhibiting high dispersibility and no agglomeration.

[0079] Example 2

[0080] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the water vapor flow rate is controlled at 1.26 L / min.

[0081] The average particle size of germanium dioxide prepared in this embodiment was found to be 10 μm.

[0082] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 3 As shown. From Figure 3 It is evident that germanium dioxide consists of individual spherical particles, exhibiting high dispersibility and no agglomeration.

[0083] Example 3

[0084] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the vaporization temperature of germanium tetrachloride is 140°C.

[0085] The average particle size of germanium dioxide prepared in this embodiment was found to be 29 μm.

[0086] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 4 As shown. From Figure 4 It is evident that germanium dioxide exhibits good dispersibility and no agglomeration.

[0087] Example 4

[0088] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the water vapor flow rate is controlled at 0.18 L / min.

[0089] The average particle size of germanium dioxide prepared in this embodiment was found to be 24 μm.

[0090] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 5 As shown. From Figure 5 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0091] Example 5

[0092] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the water vapor flow rate is controlled at 5.4 L / min.

[0093] The average particle size of germanium dioxide prepared in this embodiment was found to be 6 μm.

[0094] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 6 As shown. From Figure 6 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0095] Example 6

[0096] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that: the reactor is first heated to 300°C; the water vapor flow rate is controlled at 1.26 L / min, and the temperature at which the chemical vapor deposition reaction occurs is 300°C.

[0097] The average particle size of germanium dioxide prepared in this embodiment was found to be 8 μm.

[0098] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 7 As shown. From Figure 7 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0099] Example 7

[0100] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that: the reactor is first heated to 700°C; the water vapor flow rate is controlled at 1.26 L / min, and the temperature at which the chemical vapor deposition reaction occurs is 700°C.

[0101] The average particle size of germanium dioxide prepared in this embodiment was found to be 6 μm.

[0102] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 8 As shown. From Figure 8 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0103] Example 8

[0104] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the carrier gas flow rate is set to 0.1 L / min and the water vapor flow rate is controlled to be 1.26 L / min.

[0105] The average particle size of germanium dioxide prepared in this embodiment was found to be 8 μm.

[0106] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 9 As shown. From Figure 9 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0107] Example 9

[0108] This embodiment provides a method for preparing highly dispersible spherical germanium dioxide, which differs from Example 1 only in that the carrier gas flow rate is set to 1 L / min and the water vapor flow rate is controlled to be 1.26 L / min.

[0109] The average particle size of germanium dioxide prepared in this embodiment was found to be 8 μm.

[0110] Scanning electron microscope (SEM) images of germanium dioxide prepared in this embodiment are shown below. Figure 10 As shown. From Figure 10 It is evident that germanium dioxide exhibits good dispersibility and exhibits no agglomeration.

[0111] Comparative Example 1

[0112] Germanium dioxide was prepared by conventional hydrolysis: germanium tetrachloride and deionized water were mixed at a volume ratio of 1:7 and stirred at 25°C and 120 r / min for 10 h. After precipitation, filtration, washing and drying, germanium dioxide product was obtained.

[0113] Scanning electron microscope images of the germanium oxide prepared in this comparative example are shown below. Figure 11 As shown in the figure, the germanium oxide prepared by this method exhibits severe agglomeration.

[0114] Comparative Example 2

[0115] This comparative example provides a method for preparing germanium dioxide, which differs from Example 1 only in that the vaporization temperature of germanium tetrachloride is 150°C.

[0116] Scanning electron microscope images of germanium dioxide prepared in this comparative example are shown below. Figure 12 As shown. From Figure 12 It is evident that germanium dioxide exhibits poor dispersibility and severe agglomeration.

[0117] Comparative Example 3

[0118] This comparative example provides a method for preparing germanium dioxide, which differs from Example 1 only in that: the reactor is first heated to 800°C; the water vapor flow rate is controlled at 1.26 L / min, and the temperature at which the chemical vapor deposition reaction occurs is 800°C.

[0119] Scanning electron microscope images of germanium dioxide prepared in this comparative example are shown below. Figure 13 As shown. From Figure 13 It is evident that germanium dioxide exhibits poor dispersibility, severe agglomeration, and uneven particle size.

[0120] Comparative Example 4

[0121] This comparative example provides a method for preparing germanium dioxide, which differs from Example 1 only in that the water vapor flow rate is controlled at 0.05 L / min.

[0122] Scanning electron microscope images of germanium dioxide prepared in this comparative example are shown below. Figure 14 As shown. From Figure 14 It is evident that germanium dioxide exhibits poor dispersibility and severe agglomeration.

[0123] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing highly dispersible spherical germanium dioxide, characterized in that, include: 1) The fluidized bed chemical vapor deposition reactor is purged with carrier gas to fill the reactor with the carrier gas; 2) Germanium tetrachloride is evaporated and vaporized at 100-145℃, and the carrier gas carries the germanium tetrachloride vapor into the reactor; deionized water is vaporized, and the water vapor enters the reactor; wherein, the flow rate of the carrier gas is 0.1-1 L / min; and the flow rate of the water vapor is 0.1-5.4 L / min. The temperature of the reactor is controlled so that the germanium tetrachloride vapor and the water vapor undergo a chemical vapor deposition reaction at 300-750°C to generate germanium dioxide. 3) Cool down to obtain highly dispersed spherical germanium dioxide.

2. The method for preparing highly dispersible spherical germanium dioxide according to claim 1, characterized in that, The vaporization temperature of the germanium tetrachloride is 100-140℃, more preferably 110-130℃.

3. The method for preparing highly dispersible spherical germanium dioxide according to claim 1 or 2, characterized in that, The flow rate of the water vapor is 0.18-1.8 L / min.

4. The method for preparing highly dispersible spherical germanium dioxide according to any one of claims 1-3, characterized in that, The temperature of the chemical vapor deposition reaction is 300-700℃; preferably 300℃, 350℃, 400℃, 500℃, 600℃ or 700℃.

5. The method for preparing highly dispersible spherical germanium dioxide according to any one of claims 1-4, characterized in that, The carrier gas is nitrogen.

6. Germanium dioxide prepared by the method according to any one of claims 1-5; Preferably, the germanium dioxide has a purity of 99.9%; Preferably, the germanium dioxide has an average particle size of 5-20 μm.

7. A dedicated apparatus for preparing germanium dioxide by fluidized bed chemical vapor deposition, characterized in that, include: Carrier gas supply equipment, used to provide carrier gas; Germanium tetrachloride evaporator is used to vaporize germanium tetrachloride into germanium tetrachloride vapor; Fluidized bed chemical vapor deposition reactor, used for chemical vapor deposition reactions; The carrier gas supply device is connected to the inlet of the germanium tetrachloride evaporator, and the outlet of the germanium tetrachloride evaporator is connected to the inlet at the bottom of the reactor, so that germanium tetrachloride vapor enters the interior of the reactor through the bottom of the reactor under the carrier gas. A steam generator is used to vaporize deionized water into steam; the outlet of the steam generator is connected to the inlet at the bottom of the reactor so that the steam enters the interior of the reactor through the bottom of the reactor.

8. The special device according to claim 7, characterized in that, The reactor also includes a heater for supplying heat to the reactor; Preferably, the heater is a heating furnace, which is disposed on the outer wall of the reactor.

9. The special device according to claim 7 or 8, characterized in that, The reactor also includes a porous gas distribution plate disposed at the bottom of the reactor for uniformly distributing the gas.

10. The special device according to claim 7 or 8, characterized in that, The device also includes a product collector for collecting germanium dioxide particles; Preferably, the device further includes an exhaust gas absorption device connected to the top outlet of the product collector for absorbing exhaust gas.

Images