Method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen

Abstract

The invention discloses a method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen. The method comprises the following steps: step 1, charging; 2, replacing air in the furnace; step 3, heating reduction; 4, performing reduction gas-liquid separation; and 5, cooling and discharging. According to the method, by designing a new reduction method and a new reduction reaction device, the actual consumption amount of hydrogen is close to the theoretical demand amount, the utilization efficiency, reduction efficiency and germanium recovery rate of hydrogen are improved, the time required by the whole reduction process is shortened, the power consumption is reduced, the daily productivity of single equipment is improved, the operation is simple, and the cost is low. The acidic water vapor is recycled after being condensed, more than 1% of germanium metal is recycled, and no waste gas is discharged to influence the environment.

Description

Technical Field

[0001] The invention belongs to the technical field of high-purity semiconductor germanium material preparation, and in particular relates to a method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen. Background Art

[0002] High-purity metallic germanium powder, whose purity usually reaches or exceeds 5N (99.999%), is the raw material for producing high-purity germanium materials. Due to its excellent semiconductor and optoelectronic properties, it has important applications in high-tech fields such as aerospace, medical, national defense, and optical communications. In emerging technology fields such as quantum computing and artificial intelligence, the demand for high-performance semiconductor materials continues to increase, thereby driving the market demand and price increases for high-purity germanium materials. At present, the main production method of high-purity germanium is to reduce germanium dioxide with hydrogen to obtain high-purity germanium powder, and then regionally smelt and purify the high-purity germanium powder to obtain high-purity germanium metal.

[0003] The main process for reducing high-purity germanium dioxide is hydrogen reduction. The chemical reaction equation is as follows: 2H 2 +GeO 2 =2H 2 O+Ge, this reduction method has outstanding advantages and good selectivity. It can efficiently convert germanium dioxide into single germanium metal, and the product purity can reach a high purity level (above 99.999%). According to specific process requirements, the reaction parameters can be flexibly adjusted to meet different product quality requirements. This process has a wide range of applications, whether it is large-scale industrial production or small-scale experimental research.

[0004] At present, conventional methods for reducing high-purity germanium dioxide with hydrogen include intermittent horizontal quartz tube furnace reduction method and continuous horizontal quartz tube furnace reduction method.

[0005] Whether it is intermittent tubular furnace reduction or continuous tubular furnace reduction, the actual consumption of hydrogen is quite different from the theoretical consumption. The main reason for this difference is that it is difficult for hydrogen to fully contact germanium dioxide. Since the flow direction of hydrogen is parallel to the surface of germanium dioxide in the graphite boat, hydrogen will react with the uppermost germanium dioxide first. The germanium powder generated by the reaction adheres to the germanium dioxide, which hinders the further reaction of hydrogen with the germanium dioxide below. At the same time, hydrogen is constantly flowing, and part of the hydrogen moves to the tail of the furnace before it can react or is taken away by the generated water vapor, resulting in a prolonged reduction reaction time and increased hydrogen consumption. Summary of the invention

[0006] In view of the problems of long reaction time, high power consumption, low yield, failure to recover germanium-containing water vapor, and affecting germanium recovery rate in the current horizontal quartz tubular furnace hydrogen reduction method of high-purity germanium dioxide, a method for preparing high-purity germanium powder by using vertical stainless steel tubular furnace hydrogen reduction of high-purity germanium dioxide was invented. By designing a new reduction method and reduction furnace, the purpose of increasing the processing capacity of a single furnace, shortening the production time, reducing power consumption, and improving the germanium recovery rate is achieved.

[0007] In order to solve the above problems, the present invention provides a method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen, characterized in that it comprises the following steps: The first step is to load materials; weigh 10kg-15kg of high-purity germanium dioxide and load it into a cleaned stainless steel reduction reactor, then put the stainless steel reduction reactor into a vertical stainless steel tubular furnace from the upper end, and close the tubular furnace; the vertical stainless steel tubular furnace consists of a tubular furnace, a heating furnace body, a thermal insulation layer, a high-purity hydrogen gas supply pipe, an air-cooled cooler, a water-cooled cooler and a gas-liquid separator; the tubular furnace is vertically arranged in the heating furnace body, and a thermal insulation layer is arranged outside the heating furnace body; the high-purity hydrogen gas supply pipe passes through the heating furnace body and is connected to the top of the tubular furnace; an air outlet pipe is arranged at the bottom of the heating furnace body, and the air outlet pipe is connected to the air-cooled cooler; the air-cooled cooler is connected to the gas-liquid separator through the water-cooled cooler; the high-purity hydrogen gas supply pipe is provided with a ball valve and a metal rotor flowmeter; the lower part of the water-cooled cooler is provided with a coolant inlet, and the upper part is provided with a coolant outlet; the lower part of the gas-liquid separator is provided with a drain port, the upper part is provided with an air outlet, and the air outlet is provided with a back pressure valve; The second step is to replace the air in the furnace; open the first ball valve, adjust the metal rotor flowmeter, introduce hydrogen, and replace the air in the entire reduction furnace system; The third step is heating reduction; the hydrogen flow rate is set to 1L / min-5L / min, the preheating time is set to 2h-3h, and after the temperature is raised to 640℃-680℃, the metal rotor flowmeter is adjusted to set the hydrogen flow rate to 10L / min-15L / min, and then the reduction is carried out at this temperature for 6h-8h; The fourth step is to reduce the gas-liquid separation; Step 5: Cool and remove from the oven.

[0008] Furthermore, the reducing gas-liquid separation is that the coolant enters from the water inlet and flows out from the water outlet, and the reducing water vapor generated by the reaction is water-cooled. The reducing water vapor is condensed into water by the cooler and flows into the gas-liquid separator along the pipeline, and the uncondensed unreacted hydrogen enters the gas-liquid separator through the pipeline; the gas in the gas-liquid separator can be discharged through the back pressure valve for recycling, and the water generated by the cooling and collection of the reduction can be discharged from the drain outlet for recycling.

[0009] Furthermore, after the reduction reaction is completed, the product is cooled for 2h-3h, and a certain amount of nitrogen is introduced to completely replace the hydrogen in the reduction furnace system. When the temperature of the stainless steel tubular furnace is cooled to 25°C, the furnace door is opened, the stainless steel reduction reactor is taken out, and the high-purity reduced germanium powder is collected.

[0010] The method of the present invention makes the actual consumption of hydrogen close to the theoretical required amount by designing a new reduction method and reaction device, improves the utilization efficiency, reduction efficiency and germanium recovery rate of hydrogen, shortens the time required for the entire reduction process, reduces power consumption, and increases the daily production capacity of a single device. The operation is simple, and the acidic water vapor is condensed and recycled, and more than 1% of germanium metal is recovered, and no waste gas is emitted to affect the environment. In addition, the reduction furnace of the method of the present invention is made of 316L and 310 stainless steel materials as a whole, which further improves the durability, safety and process stability of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 The present invention is a flow chart of a method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen; Figure 2 It is a structural diagram of a vertical stainless steel tubular furnace.

[0012] Reference numerals: 1: High-purity hydrogen supply pipe; 2: Ball valve; 3: Metal rotor flowmeter; 4: Tubular furnace; 5: Insulation layer; 6: Heating furnace body; 7: Air-cooled cooler; 8: Coolant outlet; 9: Coolant inlet; 10: Water-cooled cooler; 11: Back pressure valve; 12: Gas-liquid separator; 13: Drain outlet. DETAILED DESCRIPTION

[0013] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0014] like Figure 1 As shown, a method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen is provided, characterized in that it comprises the following steps: The first step is to load the material; weigh 10kg-15kg of high-purity germanium dioxide and put it into a clean stainless steel reduction reactor, then put the stainless steel reduction reactor into a vertical stainless steel tubular furnace from the top and close the tubular furnace; Figure 2As shown, the vertical stainless steel tubular furnace consists of a tubular furnace 4, a heating furnace body 6, an insulation layer 5, a high-purity hydrogen gas supply pipe 1, an air-cooled cooler 7, a water-cooled cooler 10 and a gas-liquid separator 12; the tubular furnace 4 is vertically arranged in the heating furnace body 6, and an insulation layer 5 is arranged outside the heating furnace body 6; the high-purity hydrogen gas supply pipe 1 passes through the heating furnace body 6 and is connected to the top of the tubular furnace 4; an outlet pipe is arranged at the bottom of the heating furnace body 6, and the outlet pipe is connected to the air-cooled cooler 7; the air-cooled cooler 7 is connected to the gas-liquid separator 12 through the water-cooled cooler 10; the high-purity hydrogen gas supply pipe 1 is provided with a ball valve 2 and a metal rotor flowmeter 3; the water-cooled cooler 10 is provided with a coolant water inlet 9 at the bottom, and a coolant water outlet 8 at the top; the gas-liquid separator 12 is provided with a drain 13 at the bottom, and an outlet at the top, and the outlet is provided with a back pressure valve 11; The second step is to replace the air in the furnace; open the first ball valve 2, adjust the metal rotor flowmeter 3, and introduce hydrogen to replace the air in the entire reduction furnace system; The third step is heating reduction; the hydrogen flow rate is set to 1L / min-5L / min, the preheating time is set to 2h-3h, after the temperature is raised to 640℃-680℃, the metal rotor flowmeter 2 is adjusted, the hydrogen flow rate is set to 10L / min-15L / min, and then the temperature is kept constant for 6h-8h; The fourth step is to separate the reduction gas and liquid; the coolant enters from the water inlet 9 and flows out from the water outlet 8, and the reduction water vapor generated by the reaction is water-cooled. The reduction water vapor is condensed into water by the cooler and flows into the gas-liquid separator 12 along the pipeline, and the uncondensed unreacted hydrogen enters the gas-liquid separator 12 through the pipeline; the gas in the gas-liquid separator 12 can be discharged through the back pressure valve 11 for recycling, and the water generated by the cooling and collection of the reduction can be discharged from the drain port 13 for recycling; The fifth step is cooling and taking out of the furnace; after the reduction reaction is completed, the temperature is lowered and cooled for 2h-3h, and a certain amount of nitrogen is introduced to completely replace the hydrogen in the reduction furnace system. When the temperature of the stainless steel tubular furnace is cooled to 25°C, the furnace door is opened, the stainless steel reduction reactor is taken out, and the high-purity reduced germanium powder is collected.

[0015] The comparison between the method of the present invention and the currently used process is shown in Table 1.

[0016] Table 1 Comparison between the method of the present invention and the currently used process Method Name Vertical stainless steel tubular furnace reduction method of the present invention Horizontal quartz tube furnace reduction method Continuous horizontal quartz tube furnace reduction method Germanium dioxide reduction amount per furnace (kg) 10-13 2.0-2.5 5-6 Rated power (kW) 25 15 / Error between set temperature and actual temperature (℃) ±1 ±10 ±10 Actual consumption ratio of hydrogen Approximately 1.1 times the theoretical requirement About 10 times the theoretical requirement About 9 times the theoretical requirement Hydrogen source Hydrogen production by water electrolysis Photocatalysis <![CDATA[The mixed gas produced by the decomposition of liquid ammonia (25% N 2 + 75% H 2 ).]]> <![CDATA[The mixed gas generated by the decomposition of liquid ammonia (25% N 2 + 75% H 2 ).]]> Process time (h) 15 22 25 Tubular furnace material Stainless steel pipe sleeve Quartz tube Quartz tube Acidic water vapor generated by reduction Acidic water vapor is condensed and recycled, recovering 1% more germanium without affecting the environment Acidic water vapor is not recycled, germanium loss is about 1%, and it is directly discharged, which affects the environment Acidic water vapor is not recycled, germanium loss is about 1%, and it is directly discharged, which affects the environment

[0017] Compared with the currently used process methods, the method of the present invention adopts a vertical arrangement of the tubular furnace, and the hydrogen flows in a way of entering from the top and exiting from the bottom. Before the hydrogen enters the tubular furnace, it passes through the heating furnace body along the pipeline for preheating, so as to avoid the cold hydrogen entering the tubular furnace and causing loss of reduction temperature. When the hydrogen enters from the upper end of the tubular furnace, it diffuses rapidly due to its low density, forming a certain airflow pattern. During the flow of hydrogen, it gradually penetrates the gaps between the germanium dioxide through the interaction with the high-purity germanium dioxide. In this process, the airflow promotes the movement of the high-purity germanium dioxide particles. Since the particles of the high-purity germanium dioxide are small and have a certain fluidity, the powder will be suspended, thereby increasing the contact area between the hydrogen and the high-purity germanium dioxide and the chance of effective reaction. The flow of the gas can also cause vibration and collision of the small particles, further promoting the acceleration of the reaction. The reducing water vapor generated by the reaction will naturally deposit at the lower end of the reduction furnace because its density is greater than that of hydrogen, and will be discharged out of the reduction furnace from the outlet at the lower end of the tubular furnace. This method can make the hydrogen and high-purity germanium dioxide contact more fully. Compared with the current reduction method, the utilization rate and reduction efficiency of hydrogen become higher, and the actual consumption of hydrogen is closer to the theoretical requirement.

[0018] It can be seen from Table 1 that, compared with the currently used process methods, the beneficial technical effects brought about by the technical solution of the present invention are: The method of the present invention makes the actual consumption of hydrogen close to the theoretical required amount by designing a new reduction method and reaction device, improves the utilization efficiency, reduction efficiency and germanium recovery rate of hydrogen, shortens the time required for the entire reduction process, reduces power consumption, and increases the daily production capacity of a single device. The operation is simple, and the acidic water vapor is condensed and recycled, and more than 1% of germanium metal is recovered, and no waste gas is emitted to affect the environment. In addition, the reduction furnace of the method of the present invention is made of 316L and 310 stainless steel materials as a whole, which further improves the durability, safety and process stability of the equipment.

[0019] Embodiment 1: The first step is loading: weigh 10 kg of high-purity germanium dioxide with a purity of 5 N, wipe the stainless steel reactor clean and load the weighed high-purity germanium dioxide into it, open the furnace door at the upper end of the tubular furnace, put the reactor in from the upper end of the tubular furnace, and close the sealed furnace door.

[0020] The second step is to replace the air: open the first ball valve 2, pass in high-purity hydrogen with a purity of 99.999%, adjust the metal rotor flowmeter 3 to set the hydrogen flow rate to 5 L / min, and continue to pass it in for 15 minutes to replace all the air in the reduction furnace system.

[0021] The third step is heating reduction: reduce the hydrogen flow rate, set the heating program, set the heating rate to 325 ℃ / h, and heat for 2 hours. When the temperature rises to 650 ℃, run the constant temperature reduction program for 6 hours. At the same time, adjust the metal rotor flowmeter 3 to set the hydrogen flow rate to 12.5 L / min.

[0022] The fourth step is the separation of reduction gas and liquid: the coolant is passed into the water-cooled cooler from the water inlet 9 and flows out from the water outlet 8 to cool the reduction water vapor generated by the reaction. The reduction water vapor is condensed into water by the cooler and flows into the gas-liquid separator 12 along the pipeline. The non-condensed gas (unreacted hydrogen) enters the gas-liquid separator 12 through the pipeline. The gas collected in the gas-liquid separator 12 is discharged through the back pressure valve 11 for recycling, and the water generated by the cooling and collection reduction is discharged from the drain outlet 13 for recycling.

[0023] The fifth step is cooling and taking out of the furnace: after the reduction reaction is completed, the temperature is lowered and cooled for 2 hours, and nitrogen is introduced at the same time, and the nitrogen flow rate is 5L / min to completely replace the hydrogen in the reduction furnace system. When the temperature of the stainless steel tubular furnace is cooled to 25°C, the tubular furnace door is opened, and the stainless steel reduction reactor is taken out from the upper end of the tubular furnace to collect the high-purity reduced germanium powder with a purity of 99.9992%.

[0024] Embodiment 2: The first step is charging: weigh 15 kg of high-purity germanium dioxide with a purity of 5 N, wipe the stainless steel reactor clean and load the weighed high-purity germanium dioxide into it, open the furnace door at the upper end of the tubular furnace, put the reactor in from the upper end of the tubular furnace, and close the sealed furnace door.

[0025] The second step is to replace the air in the furnace: open the first ball valve 2, pass high-purity hydrogen with a purity of 99.999%, adjust the metal rotor flowmeter 3 to set the hydrogen flow rate to 4 L / min, and continue to pass it for 20 minutes to replace all the air in the reduction furnace system.

[0026] The third step is heating reduction: reduce the hydrogen flow rate, set the heating program, set the heating rate to 270 ℃ / h, and heat for 2.5 hours. When the temperature rises to 675 ℃, run the constant temperature reduction program for 8 hours. At the same time, adjust the metal rotor flowmeter 3 to set the hydrogen flow rate to 13 L / min.

[0027] The fourth step is the separation of reduction gas and liquid: the coolant is passed into the water-cooled cooler from the water inlet 9 and flows out from the water outlet 8 to cool the reduction water vapor generated by the reaction. The reduction water vapor is condensed into water by the cooler and flows into the gas-liquid separator 12 along the pipeline. The non-condensed gas (unreacted hydrogen) enters the gas-liquid separator 12 through the pipeline. The gas collected in the gas-liquid separator 12 is discharged through the back pressure valve 11 for recycling, and the water generated by the cooling and collection reduction is discharged from the drain outlet 13 for recycling.

[0028] The fifth step is cooling and taking out of the furnace: after the reduction reaction is completed, the temperature is lowered and cooled for 3 hours, and nitrogen is introduced at the same time, and the nitrogen flow rate is 3L / min to completely replace the hydrogen in the reduction furnace system. When the temperature of the stainless steel tubular furnace is cooled to 25°C, the tubular furnace door is opened, and the stainless steel reduction reactor is taken out from the upper end of the tubular furnace to collect the high-purity reduced germanium powder with a purity of 99.9994%.

[0029] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the appended claims, or the equivalent forms of such scope and boundaries.

Claims

1. A method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen, characterized in that: The following steps are involved: The first step is to load materials; weigh 10kg-15kg of high-purity germanium dioxide and put it into a cleaned stainless steel reduction reactor, then put the stainless steel reduction reactor into a vertical stainless steel tubular furnace from the upper end, and close the tubular furnace; the vertical stainless steel tubular furnace consists of a tubular furnace, a heating furnace body, an insulation layer, a high-purity hydrogen gas supply pipe, an air-cooled cooler, a water-cooled cooler and a gas-liquid separator; the tubular furnace is vertically arranged in the heating furnace body, and an insulation layer is arranged outside the heating furnace body; the high-purity hydrogen gas supply pipe passes through the heating furnace body and is connected to the top of the tubular furnace; an outlet pipe is arranged at the bottom of the heating furnace body, and the outlet pipe is connected to the air-cooled cooler; the air-cooled cooler is connected to the gas-liquid separator through the water-cooled cooler; the high-purity hydrogen gas supply pipe is provided with a ball valve and a metal rotor flowmeter; the lower part of the water-cooled cooler is provided with a coolant water inlet, and the upper part is provided with a coolant water outlet; the lower part of the gas-liquid separator is provided with a drain port, the upper part is provided with an air outlet, and the air outlet is provided with a back pressure valve; The second step is to replace the air in the furnace; open the first ball valve, adjust the metal rotor flowmeter, introduce hydrogen, and replace the air in the entire reduction furnace system; The third step is heating reduction; the hydrogen flow rate is set to 1L / min-5L / min, the preheating time is set to 2h-3h, and after the temperature is raised to 640℃-680℃, the metal rotor flowmeter is adjusted to set the hydrogen flow rate to 10L / min-15L / min, and then the reduction is carried out at this temperature for 6h-8h; The fourth step is to reduce the gas-liquid separation; Step 5: Cool and remove from the oven.

2. The method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen according to claim 1, characterized in that: The reduction gas-liquid separation is to allow the coolant to enter from the water inlet and flow out from the water outlet, and water-cool the reduction water vapor generated by the reaction, and then enter the gas-liquid separator after cooling; the gas in the gas-liquid separator can be discharged through the back pressure valve for recycling, and the water generated by the cooling and collection of the reduction can be discharged from the drain outlet for recycling.

3. The method for producing high-purity germanium powder by reducing high-purity germanium dioxide with hydrogen according to claim 1, characterized in that: The cooling out of the furnace is to cool down for 2h-3h after the reduction reaction is completed, and at the same time, introduce a certain amount of nitrogen to completely replace the hydrogen in the reduction furnace system. When the temperature of the stainless steel tubular furnace is cooled to 25°C, open the furnace door, take out the stainless steel reduction reactor, and collect the high-purity reduced germanium powder.

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