Device and method for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen

Abstract

The embodiment of the present application relates to a device and method for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide, belonging to the technical fields of germanium metallurgy and preparation of high-purity germanium materials. The device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide in the embodiment of the present application includes a furnace body. A furnace tube is penetrated through the furnace body, and both ends of the furnace tube extend outside the furnace body and are fixed by a furnace tube support. The furnace tube support is fixedly arranged on the furnace body. Inside the furnace tube, a graphite crucible assembly and a furnace plug are sequentially arranged from bottom to top, and there is a gap between the graphite crucible assembly and the furnace plug. The present application greatly reduces the usage amount of hydrogen, significantly improves the hydrogen utilization rate, and shortens the production cycle.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of germanium metallurgy and the preparation of high-purity germanium materials, and particularly to a device and method for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide. Background Art

[0002] High-purity germanium is an important raw material for growing single-crystal germanium, which is obtained by hydrogen reduction of germanium dioxide at high temperature. The reaction formula is as follows:

[0003]

[0004] At present, the process of hydrogen reduction of germanium dioxide mainly uses a traditional horizontal tube furnace. When hydrogen reacts with high-purity germanium dioxide powder, the contact area is relatively small. Especially during the reduction process, the high-purity germanium dioxide powder is loaded in a graphite boat. When the reaction occurs, hydrogen flows through the upper layer of the graphite boat and contacts the surface of the germanium dioxide powder to undergo a reduction reaction, generating a germanium powder product layer. In order to further reduce, hydrogen must diffuse through the product layer. As the reaction progresses, the formed germanium powder product layer adheres to the surface of the germanium dioxide powder. As the germanium powder product layer gradually thickens, the hindrance to the diffusion of hydrogen into the germanium dioxide powder increases. This not only increases the reduction reaction time, resulting in a long reduction cycle and difficult improvement of production efficiency, but also causes a large amount of hydrogen consumption and waste, increasing costs (the schematic diagram of the hydrogen reduction of germanium dioxide by a traditional horizontal tube furnace is as Figure 1 )). In addition, the current horizontal tube furnace reduction system also has uneven temperature, which leads to the formation of intermediate product germanium monoxide during the reduction reaction. If the supply of hydrogen participating in the reduction reaction is insufficient at this time, when the temperature exceeds 710 °C, germanium monoxide cannot be reduced to germanium powder in time and directly sublimes and volatilizes, resulting in the loss of germanium and a decrease in the recovery rate of germanium. Part of the volatilized germanium monoxide will adhere to the furnace wall of the tube furnace and the gas pipeline, and the other part will be discharged with the tail gas, resulting in the pollution of the reduction equipment and the loss of raw materials. Due to the limitations of factors such as the horizontal tube furnace of the existing equipment, the diameter of the quartz tube, and the density of the germanium dioxide powder, as the amount of germanium dioxide loaded in the graphite boat increases and thickens, the reduction efficiency will be significantly reduced.

[0005] Currently, the main problems of the existing solutions are: large hydrogen consumption, insufficient contact with germanium dioxide powder, serious waste, low reduction efficiency, long production cycle, and reduced recovery rate of the reduction product germanium due to the volatilization of intermediate products. Chinese Patent No. CN115627371A discloses a cyclone purification system for the reduction and purification of germanium dioxide. The germanium dioxide powder is in full contact with hydrogen in the cyclone separation cylinder, significantly improving the efficiency of reducing germanium dioxide powder to prepare germanium ingots and reducing the preparation cost; however, there are problems such as complex device structure, difficult control of temperature uniformity, and limited output. Summary of the Invention

[0006] In view of this, the embodiments of the present application provide a device and a method for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide, enabling hydrogen to directly enter the interior of the graphite crucible, fully contact with germanium dioxide and react. The unconsumed hydrogen undergoes reflux under the blockage of the gas diversion cover and reacts with germanium dioxide again, achieving full utilization of hydrogen. At the same time, the intermediate product germanium monoxide generated during the reduction reaction is volatile and refluxes under the blockage of the upper gas diversion cover and continues to react with hydrogen, reducing germanium loss. The present application significantly reduces the usage amount of hydrogen in the production process of preparing high-purity germanium powder by hydrogen reduction of germanium dioxide, remarkably improves the utilization rate of hydrogen, and shortens the reduction production cycle, solving the problems of low efficiency, high cost, large germanium loss, and long reduction cycle existing in the prior art when using hydrogen to reduce high-purity germanium dioxide to prepare high-purity germanium powder.

[0007] In the first aspect of the embodiments of the present application, a device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide is provided. The device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide includes a furnace body, a furnace tube is disposed through the furnace body, and both ends of the furnace tube extend outside the furnace body and are fixed by a furnace tube support, and the furnace tube support is fixedly arranged on the furnace body; a graphite crucible assembly and a furnace plug are sequentially arranged in the furnace tube from bottom to top, and there is a gap between the graphite crucible assembly and the furnace plug.

[0008] In some embodiments that may include the above embodiments, the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide further includes a hollow support column, the hollow support column is used to support the graphite crucible assembly and fix it in the furnace tube, and the hollow support column is also used to introduce reaction gas into the graphite crucible assembly.

[0009] In some embodiments that may include the above embodiments, the graphite crucible assembly includes a graphite crucible, the graphite crucible has a cylindrical structure with openings at both ends, and gas diversion covers are arranged at both ends of the graphite crucible, and dense sieve-shaped through holes are arranged on the gas diversion covers.

[0010] In some embodiments that may include the above embodiments, the hollow support column is flush with the bottom of the graphite crucible.

[0011] In some embodiments that may include the above embodiments, the gas diversion cover protrudes inwardly towards the interior of the graphite crucible, the protrusion is adapted to the port of the graphite crucible, the protruding part is communicated with the gas diversion cover, and dense sieve-shaped through holes are also arranged around the protruding part.

[0012] In some embodiments that may include the above embodiments, external threads are further arranged around the protruding part, and internal threads adapted to the external threads are arranged at the port of the graphite crucible, and the protrusion and the graphite crucible are threadedly connected.

[0013] In some embodiments that may include the above embodiments, the diameter of the through hole is less than 10 mm.

[0014] In some embodiments that may include the above embodiments, the hollow strut is a stainless steel strut.

[0015] In some embodiments that may include the above embodiments, the furnace tube is a quartz tube, and a vacuum gauge is further provided on the furnace body.

[0016] In the second aspect of the embodiments of the present application, a method for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide is further provided. Using the above device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide, the method includes the following steps:

[0017] Step 1: Place germanium dioxide powder in a graphite crucible, cover both ends of the graphite crucible with a gas diversion cover, and then place the covered graphite crucible into the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide containing hollow struts;

[0018] Step 2: Horizontally place the lower end of the graphite crucible on the hollow strut, evacuate the furnace chamber, and displace the air in the furnace chamber with an inert gas;

[0019] Step 3: After the inert gas displacement in Step 2 is completed, introduce the reducing gas H2 into the graphite crucible through the hollow strut, and at the same time, turn on the heating system of the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide to reach a certain temperature and then keep it warm for a reduction reaction;

[0020] Step 4: Pour out and collect the germanium powder obtained by reduction in Step 3 from the graphite crucible to obtain the product.

[0021] It should be noted that this application is different from the conventional way of the reducing gas first entering the furnace tube and then infiltrating into the crucible to react with the material in a tube furnace, effectively increasing the production capacity and improving the production efficiency; this application can adjust the reaction temperature, heating rate, and hydrogen gas flow rate according to the weight of the germanium dioxide powder to be reduced; by controlling process parameters such as the reduction temperature and gas flow rate, the particle size of the reduced high-purity germanium powder can be controlled.

[0022] Compared with the prior art, the embodiments of the present application have the following beneficial effects:

[0023] 1. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen in the embodiment of the present application allows hydrogen to directly enter the graphite crucible and fully contact with germanium dioxide to undergo a reduction reaction, thereby ensuring that hydrogen is fully in contact with germanium dioxide, improving the reduction efficiency, and shortening the reduction production cycle. At the same time, due to the obstruction of the gas guide cover on the graphite crucible, the unreacted hydrogen is further fully utilized by reflux in the graphite crucible, greatly improving the utilization rate of hydrogen, and solving the problems of large hydrogen flow, serious waste, and high cost in the traditional industrial production of preparing germanium powder by reducing high-purity germanium dioxide with hydrogen;

[0024] 2. In the embodiment of the present application, the graphite crucible is cylindrical, and high-purity germanium dioxide is placed inside the graphite crucible. Hydrogen flows through the inside of the graphite crucible, fully contacts and reacts with the germanium dioxide, and the unconsumed hydrogen refluxes under the obstruction of the gas guide cover and reacts with the germanium dioxide again, so that the hydrogen is fully utilized; at the same time, the volatile intermediate product (germanium monoxide) produced in the reduction reaction is prevented from being directly discharged with the tail gas under the obstruction of the upper gas guide cover, and remains in the graphite crucible to continue to react with the hydrogen, thereby reducing the loss of the product germanium powder; in the production process of reducing germanium dioxide to prepare germanium powder, the amount of hydrogen used is greatly reduced, the reduction production cycle is shortened, the utilization efficiency of hydrogen is significantly improved, and the pollution and loss of equipment and high-purity germanium in the process of reducing high-purity germanium dioxide to prepare germanium powder by hydrogen are effectively reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a schematic diagram of the process of reducing germanium dioxide with hydrogen in a traditional horizontal tube furnace;

[0027] Figure 2 Schematic diagram of gas flow dispersion in the furnace tube of the embodiment of the present application;

[0028] Figure 3 A cross-sectional view of a device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen in an embodiment of the present application;

[0029] Figure 4 A schematic diagram of the side structure of the gas guide cover according to an embodiment of the present application;

[0030] Figure 5 A schematic diagram of the front structure of the gas guide cover according to an embodiment of the present application;

[0031] Figure 6A sample of metal Ge powder prepared by reducing GeO2 with hydrogen in Example 2 of the present application;

[0032] Figure 7 XRD pattern of the metal Ge powder sample prepared by hydrogen reduction of GeO2 in Example 2 of the present application.

[0033] Description of reference numerals:

[0034] 1. Furnace tube; 2. Furnace tube bracket; 3. Graphite crucible; 4. Gas guide cover; 5. Furnace plug; 6. Hollow pillar; 7. Through hole. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0036] Unless otherwise specified, the experimental methods used in the examples of this application are all conventional methods.

[0037] In the following examples, unless otherwise specified, all raw materials can be obtained by commercial purchase or conventional methods.

[0038] Example 1

[0039] like Figure 2-5 As shown, an embodiment of the present application provides a device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen, comprising a furnace body, a furnace tube 1 is penetrated in the furnace body, both ends of the furnace tube 1 extend outside the furnace body and are fixed by furnace tube brackets 2, and the furnace tube brackets 2 are fixedly arranged on the furnace body; a graphite crucible assembly and a furnace plug 5 are sequentially arranged in the furnace tube 1 from bottom to top, a stainless steel pipe is connected to the air outlet at the upper end of the furnace tube 1, and the furnace plug 5 is threadedly fixedly connected to the stainless steel pipe to realize the fixation of the furnace plug 5 in the furnace tube 1, and there is a gap between the graphite crucible assembly and the furnace plug 5.

[0040] Furthermore, it also includes a hollow pillar 6, which is used to support the graphite crucible assembly to be fixed in the furnace tube 1, and the hollow pillar 6 is also used to introduce reaction gas into the graphite crucible assembly; illustratively, the hollow pillar 6 is a stainless steel pillar.

[0041] Specifically, the graphite crucible assembly includes a graphite crucible 3, which is a cylindrical structure with openings at both ends. The height of the graphite crucible 3 is adjusted according to the charge mass and the heating temperature zone of the tubular furnace, and is preferably 300 mm or 500 mm; gas guide covers 4 are provided at both ends of the graphite crucible 3, and dense sieve-like through holes 7 are provided on the gas guide covers 4.

[0042] Exemplarily, the hollow support column 6 is arranged flush with the bottom of the graphite crucible 3, which can effectively ensure that hydrogen enters the graphite crucible 3 dispersedly through the through holes 7 on the gas diversion cover 4 at the bottom of the graphite crucible 3.

[0043] Further, the gas diversion cover 4 protrudes towards the inside of the graphite crucible 3, and the protrusion is adapted to the port of the graphite crucible 3. Preferably, the protruding part is cylindrical, and more preferably the height of the protruding part is 8 - 30 mm; the protruding part is communicated with the gas diversion cover 4, and a dense sieve-shaped through hole 7 is also arranged around the protruding part; Exemplarily, the diameter of the through hole 7 is less than 10 mm, preferably less than 5 mm, and more preferably less than 3 mm. While the graphite crucible 3 functions as a charging container and a heating element during the smelting process, through the design of the protruding part and the sieve-shaped through hole gas diversion cover, the airflow entering the graphite crucible 3 can be dispersed in the graphite crucible 3, fully reacting with the material; at the same time, the graphite crucible 3 can make the reaction gas passing through the graphite crucible 3 flow back, prolonging the contact time between the gas and the material and reducing the waste of raw material gas; during the reaction process, the volatile intermediate product germanium monoxide generated will not be directly discharged with the tail gas under the blockage of the upper gas diversion cover 4, effectively reducing the pollution of the equipment and high-purity germanium and the loss of raw materials in the process of preparing germanium powder by hydrogen reduction of germanium dioxide.

[0044] Specifically, an external thread is further arranged around the protruding part, and an internal thread adapted to the external thread is arranged at the port of the graphite crucible 3. The protruding part and the graphite crucible 3 are threadedly connected, which is convenient for disassembly and assembly for operations such as charging and discharging.

[0045] Further, the furnace tube 1 is a quartz tube, and a vacuum gauge is also arranged on the furnace body. The vacuum gauge is a prior art and will not be elaborated herein in this application.

[0046] In addition, the hollow support column 6 and the graphite crucible assembly can be detachably replaced as the use time extends, which can effectively avoid equipment pollution and reduce equipment maintenance costs.

[0047] Example 2

[0048] The method for preparing high-purity germanium powder by hydrogen reduction of high-purity germanium dioxide in this example uses the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide in Example 1, and includes the following steps:

[0049] Step 1: Place 10 g of GeO2 powder to be reduced in the graphite crucible, cover the gas diversion cover at both ends of the graphite crucible, and then put the covered graphite crucible into the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide containing the hollow support column;

[0050] Step 2: Horizontally place the lower end of the graphite crucible on the hollow support, evacuate the furnace chamber, and when the vacuum gauge of the furnace body shows less than 800 Pa, replace the air in the furnace chamber with high-purity nitrogen, and cycle the replacement 5 times;

[0051] Step 3: After the replacement with high-purity nitrogen in Step 2 is completed, introduce the reducing gas H2 with a flow rate of 50 ml / min. At the same time, turn on the heating system of the hydrogen reduction germanium dioxide to prepare high-purity germanium powder device (i.e., the tube furnace) at a rate of 10 °C / min. When the required reduction temperature of 650 °C is reached, keep it warm for 90 min. When all the germanium dioxide is reduced, the actual hydrogen consumption is 4500 ml, which is 1.1 times the theoretically calculated hydrogen consumption under standard conditions;

[0052] Step 4: Take out and collect the germanium powder reduced in Step 3 from the graphite crucible, and after vibrating particle size screening, high-purity germanium powder meeting the required particle size requirements can be obtained. Figure 6 Sample diagram of the metal Ge powder prepared by hydrogen reduction of GeO2 in this example; Figure 7 XRD diagram of the metal Ge powder sample prepared by hydrogen reduction of GeO2 in this example.

[0053] Example 3

[0054] The method for preparing high-purity germanium powder by hydrogen reduction of high-purity germanium dioxide in this example uses the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide in Example 1, and includes the following steps:

[0055] Step 1: Place 3 kg of GeO2 powder to be reduced in the graphite crucible, cover both ends of the graphite crucible with the gas diversion cover, and then place the covered graphite crucible into the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide with a hollow support;

[0056] Step 2: Horizontally place the lower end of the graphite crucible on the hollow support, evacuate the furnace chamber, and when the vacuum gauge of the furnace body shows less than 800 Pa, replace the air in the furnace chamber with high-purity nitrogen, and cycle the replacement 5 times;

[0057] Step 3: After the replacement with high-purity nitrogen in Step 2 is completed, introduce the reducing gas H2 with a flow rate of 100 L / h. At the same time, turn on the heating system of the hydrogen reduction germanium dioxide to prepare high-purity germanium powder device (i.e., the tube furnace) at a rate of 10 °C / min. When the required reduction temperature of 650 °C is reached, keep it warm for 15 h. When all the germanium dioxide is reduced, the actual hydrogen consumption is 1500 L, and the actual hydrogen consumption is 1.2 times the theoretically calculated hydrogen consumption under standard conditions;

[0058] Step 4: Take out and collect the germanium powder reduced in Step 3 from the graphite crucible, and after vibrating particle size screening, high-purity germanium powder meeting the required particle size requirements can be obtained.

[0059] Example 4

[0060] In the method for preparing high-purity germanium powder by hydrogen reduction of high-purity germanium dioxide in this embodiment, the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide in Embodiment 1 is used, and the method includes the following steps:

[0061] Step 1: Place 3 kg of GeO2 powder to be reduced in a graphite crucible, cover both ends of the graphite crucible with a gas diversion cover, and then place the covered graphite crucible into the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide with a hollow support column;

[0062] Step 2: Horizontally place the lower end of the graphite crucible on the hollow support column, evacuate the furnace chamber. When the vacuum gauge of the furnace body shows less than 800 Pa, replace the air in the furnace chamber with high-purity nitrogen, and circulate the replacement 5 times;

[0063] Step 3: After the replacement with high-purity nitrogen in Step 2 is completed, introduce the reducing gas H2 with a flow rate of 100 L / h. At the same time, start the heating system of the device for preparing high-purity germanium powder by hydrogen reduction of germanium dioxide (i.e., the tubular furnace) at a rate of 10 °C / min until the reduction temperature of 650 °C is reached, and keep it warm for 20 h. When all the germanium dioxide is reduced, the actual hydrogen consumption is 1500 L, and the actual hydrogen consumption is 1.2 times the theoretically calculated hydrogen consumption under standard conditions;

[0064] Step 4: Take out and collect the germanium powder reduced in Step 3 from the graphite crucible, and after vibrating particle size screening, high-purity germanium powder meeting the required particle size requirements can be obtained.

[0065] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen, characterized in that: The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen comprises a furnace body, a furnace tube is passed through the furnace body, both ends of the furnace tube extend outside the furnace body and are fixed by a furnace tube bracket, and the furnace tube bracket is fixedly arranged on the furnace body; a graphite crucible assembly and a furnace plug are arranged in sequence from bottom to top in the furnace tube, and there is a gap between the graphite crucible assembly and the furnace plug; The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen also includes a hollow support, which is used to support the graphite crucible assembly to be fixed in the furnace tube, and the hollow support is also used to introduce reaction gas into the graphite crucible assembly; The graphite crucible assembly comprises a graphite crucible, which is a cylindrical structure with openings at both ends. Both ends of the graphite crucible are provided with gas guide covers, and the gas guide covers are provided with dense sieve-like through holes.

2. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 1, characterized in that: The hollow pillar is arranged flush with the bottom of the graphite crucible.

3. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 1, characterized in that: The gas flow guide cover is protruded toward the inside of the graphite crucible, the protrusion is matched with the port of the graphite crucible, the protrusion is connected with the gas flow guide cover, and dense sieve-like through holes are also arranged around the protrusion.

4. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 3, characterized in that: The protrusion is also provided with an external thread around it, the port of the graphite crucible is provided with an internal thread matching the external thread, and the protrusion and the graphite crucible are threadedly connected.

5. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 3, characterized in that: The diameter of the through hole is less than 10 mm.

6. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 1, characterized in that: The hollow support is a stainless steel support.

7. The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to claim 1, characterized in that: The furnace tube is a quartz tube, and a vacuum gauge is also arranged on the furnace body.

8. A method for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen, characterized in that: The device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen according to any one of claims 1 to 7 comprises the following steps: Step 1, placing germanium dioxide powder in a graphite crucible, and covering both ends of the graphite crucible with gas guide covers, and then placing the covered graphite crucible into a device for preparing high-purity germanium powder by reducing germanium dioxide with hydrogen containing a hollow pillar; Step 2: The lower end of the graphite crucible is horizontally placed on a hollow support, the furnace is evacuated, and the air in the furnace is replaced with an inert gas; Step 3: After the inert gas replacement in step 2 is completed, the reducing gas H2 is introduced into the graphite crucible through the hollow pillar, and the heating system of the device for reducing germanium dioxide with hydrogen to prepare high-purity germanium powder is turned on and the temperature is kept at a certain temperature to perform a reduction reaction; Step 4: Pour the germanium powder obtained by reduction in step 3 out of the graphite crucible and collect it.

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