Method for preparing high-purity germanium through reduction of hydrogen and germanium tetrachloride

Abstract

The invention relates to a method for preparing high-purity germanium through reduction of hydrogen and germanium tetrachloride, and belongs to the technical field of high-purity metal material preparation. The method comprises the following steps: introducing vaporized germanium tetrachloride and preheated hydrogen from the top of a vertical quartz reaction tube, and mixing; the mixed gas downwards passes through a reaction zone, a concentric quartz ring tube bundle is arranged in the reaction zone, and the reaction zone is divided into an upper high-temperature reaction zone (1000-1150 DEG C), a middle medium-temperature deposition zone (600-850 DEG C) and a lower high-temperature melting zone (940-1000 DEG C) in the gas flow direction; gaseous germanium is condensed in the ring tube bundle in the middle deposition area to form solid germanium, and the solid germanium grows downwards to the lower melting area to be melted into liquid to drop and be collected; and treating the tail gas to recover germanium tetrachloride and hydrogen for recycling. Through the design of the annular tube bundle carrier and the temperature field, the deposition-melting dynamic process is achieved, reaction balance is broken, and the conversion per pass of germanium tetrachloride is increased to 70% or above.

Description

Technical Field

[0001] This application relates to the field of high-purity metal material preparation technology, and in particular to a method for preparing high-purity germanium by reducing it with hydrogen and germanium tetrachloride. Background Technology

[0002] High-purity germanium is a key material for the fabrication of germanium detectors, high-end infrared optical devices, and semiconductor substrates. Currently, the mainstream industrial process for producing high-purity germanium is "chlorination distillation to purify GeCl4 → hydrolysis to generate GeO2 → hydrogen reduction of GeO2 to obtain crude germanium → zone melting to obtain high-purity germanium." This traditional process has inherent drawbacks: The hydrolysis process has serious drawbacks: GeCl4 hydrolysis produces a large amount (about 20 times its volume) of strongly acidic germanium-containing wastewater, which has high treatment costs and great environmental pressure; the hydrolysis product GeO2 contains water and chlorine and needs to go through multiple processes such as filtration, washing, drying and calcination, which is a long process and results in material loss during turnover (such as about 1% loss due to airborne particles during screening) and a high risk of pollution.

[0003] The reduction process is inefficient and highly polluting: the reduction of GeCl4 to prepare germanium powder or the reduction of GeO2 using a bell-type furnace are both intermittent operations, resulting in low germanium conversion rates (10-15% for the former and requiring subsequent purification for the latter). When the furnace is opened after the reaction, residual GeCl4, HCl, and other highly corrosive gases escape, causing equipment corrosion, environmental pollution, and secondary contamination of the products.

[0004] High energy consumption and low purity in direct production: The resistivity of metallic germanium obtained by traditional methods is only 1~10 Ω·cm. It is necessary to rely on high-energy-consuming regional smelting for multiple purifications (the purification rate of a single purification is about 70%) to obtain high-purity germanium with a resistivity >50 Ω·cm. The overall material utilization rate is low.

[0005] To address the aforementioned issues, existing technologies have introduced a direct reduction method that skips the hydrolysis step and directly prepares germanium from GeCl4 and H2 (GeCl4 + 2H2 → Ge + 4HCl). However, this direct reduction of germanium tetrachloride using hydrogen suffers from a low single-pass germanium tetrachloride conversion rate.

[0006] For example, the method disclosed in CN116555597A, "A Short-Process Preparation of High-Purity Germanium Tetrachloride and Tail Gas Recycling Treatment Method," involves using high-purity hydrogen to carry high-purity germanium tetrachloride into a reduction furnace for reaction, depositing germanium metal on a germanium rod, and then performing zone melting purification as needed based on purity requirements. The unreacted gas is then subjected to subsequent distillation and chlorination systems to obtain high-purity hydrogen and germanium tetrachloride again, achieving tail gas recycling treatment. In this method, the single-pass germanium tetrachloride conversion rate is no higher than 32%.

[0007] How to improve the single-pass conversion rate of germanium tetrachloride in the process of reducing germanium tetrachloride with hydrogen has always been a problem that needs to be solved by those skilled in the art. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the low single-pass germanium tetrachloride conversion rate in the existing direct reduction technology, and to provide a method for producing high-purity germanium by hydrogen reduction of germanium tetrachloride with high single-pass germanium tetrachloride conversion rate.

[0009] The method for preparing high-purity germanium by reduction of germanium tetrachloride with hydrogen in this application includes the following steps: S1. Raw material pretreatment and vaporization: Germanium tetrachloride liquid is vaporized to obtain germanium tetrachloride vapor, and hydrogen is preheated to above 550°C; S2. Co-current reduction and dynamic deposition-melting reaction: First, an inert gas is introduced into the vertical quartz reaction tube to replace the gas inside the tube. Then, preheated hydrogen and germanium tetrachloride vapor are introduced from the top of the vertical quartz reaction tube and mixed in the mixing zone at the top of the tube. The mixed gas flows downward into the reaction zone, which contains a ring-shaped tube bundle extending axially along the vertical quartz reaction tube. The ring-shaped tube bundle consists of multiple concentrically arranged quartz tubes. The reaction zone is divided into three temperature zones from top to bottom along the gas flow direction: a) Upper high-temperature reaction zone: The temperature is 1000℃ ~ 1150℃, which causes the mixed gas to undergo a reduction reaction to generate gaseous germanium; b) Mid-temperature deposition zone in the middle: The temperature is 600℃ ~ 850℃, which causes gaseous germanium to condense and deposit as solid germanium on the surface of the ring tube bundle; c) Lower high-temperature melting zone: temperature 940℃ ~ 1000℃; The ring tube bundle penetrates the middle medium-temperature deposition zone from top to bottom and extends into the lower high-temperature melting zone, so that the solid germanium deposited on the ring tube bundle is melted into liquid at its end in the lower high-temperature melting zone during the downward growth process. S3. Product collection: At the bottom of the lower high-temperature melting zone, the dripping liquid germanium is collected to form a molten pool, which is then discharged continuously or intermittently; S4. Tail gas treatment and recycling: The tail gas discharged from the bottom of the vertical quartz reaction tube is condensed to separate and recover germanium tetrachloride and return it to step S1; the hydrogen chloride in the tail gas is absorbed by hydrochloric acid absorption solution; the remaining hydrogen gas after separation is partially or completely returned to step S1 for recycling.

[0010] Furthermore, the molar ratio of hydrogen gas to germanium tetrachloride vapor is 5-10:1.

[0011] Furthermore, the purity of the hydrogen gas is not less than 99.999%, and the purity of the germanium tetrachloride is not less than 99.99999%.

[0012] Furthermore, the vertical quartz tube has a diameter of 150-200mm and a length of 1-1.5m.

[0013] The working principle and beneficial effects of this application are as follows: The ring-shaped tube bundle in this application serves as a deposition carrier for solid germanium. Its enormous specific surface area greatly promotes the condensation and deposition of gaseous germanium. This process is essentially equivalent to continuously removing the product germanium from the reaction gas phase, thereby disrupting the reaction equilibrium and driving the reaction (GeCl4 + 2H2 = Ge + 4HCl) continuously to the right. This is the fundamental reason why the single-pass germanium tetrachloride conversion rate is significantly higher than that of the traditional direct reduction method. Experiments show that using the method of this invention, the single-pass germanium tetrachloride conversion rate can stably reach over 70%, which is more than double that of the conventional method.

[0014] Furthermore, this application ingeniously utilizes the temperature gradient to achieve an automated "upper deposition, lower melting" process by extending the annular tube bundle to the lower high-temperature melting zone. The deposited solid germanium is melted into droplets in the lower part and detaches from the annular tube bundle, allowing the deposition surface to "self-clean," thereby ensuring long-term continuous operation of the reactor and fundamentally solving the industry problem of easy clogging in fixed-bed deposition.

[0015] Furthermore, in this application, gaseous germanium is selectively condensed and deposited into a solid state in the medium temperature range (600-850℃), which is itself a distillation and purification process. Many volatile impurities, such as chlorides, are difficult to condense at this temperature and are thus discharged with the tail gas, resulting in a high purity of the directly produced germanium melt. Attached Figure Description

[0016] The above and other objects, features and advantages of this application will become more apparent from the more detailed description of exemplary embodiments thereof in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments thereof.

[0017] Figure 1 This is a schematic diagram of the vertical quartz reaction tube structure in this application.

[0018] In the figure, 1-ring tube bundle; 2-hydrogen inlet pipe; 3-GeCl4 vapor inlet pipe; 4-premixing zone; 5-upper high-temperature reaction zone; 6-middle medium-temperature deposition zone; 7-lower high-temperature melting zone; 8-tail gas outlet; 9-melt outlet. Detailed Implementation

[0019] The embodiments of this application will now be described in more detail with reference to the examples. While embodiments of this application are shown in the examples, it should be understood that this application can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to make this application more thorough and complete, and to fully convey the scope of this application to those skilled in the art.

[0020] Example 1 This embodiment describes a method for producing high-purity germanium by reducing germanium tetrachloride with hydrogen. The main equipment is a vertical quartz reaction tube, the structure of which is as follows: Figure 1 As shown, the quartz reaction tube has a diameter of 150 mm and a length of 1 m, and is arranged vertically. Multiple bundles of annular tubes 1 are arranged in parallel inside the quartz reaction tube. The annular tube bundle 1 is composed of multiple concentrically arranged quartz tubes. The top of the quartz reaction tube is connected to a hydrogen inlet pipe 2 and a GeCl4 vapor inlet pipe 3, respectively. The upper end face of the annular tube bundle 1 is left with a certain distance from the top of the quartz reaction tube, so that this area serves as a pre-mixing zone 4 for hydrogen and GeCl4 vapor. The method specifically includes the following steps: Preheat hydrogen gas with a purity of 5N1 to 550℃; heat GeCl4 to make it boil and form a gaseous state; Then, inert gas is first introduced into the vertical quartz reaction tube to replace the gas inside the tube. Next, H2 with a purity of 5N1 and GeCl4 vapor with a purity of 7N2 are introduced into the premixing zone 4 of the quartz tube at a molar ratio of 10:1 for mixing.

[0021] The mixed gas descends into the main reaction zone under the influence of gravity and airflow. This main reaction zone contains multiple ring tube bundles extending axially along the reaction tube axis. The main reaction zone is divided into three temperature zones from top to bottom along the downward direction of the airflow: a) Upper high-temperature reaction zone 5: The temperature is 1000℃ ~ 1150℃. At this high temperature, the mixed gas undergoes a violent reduction reaction, mainly producing gaseous germanium. In this embodiment, the temperature of this zone is 1050℃. b) Middle-temperature deposition zone 6: The temperature is 600℃ ~ 850℃. High-temperature gaseous germanium from the upper part reaches a supersaturated state in this region, thus selectively condensing and depositing on the large surface of the ring tube bundle to form a solid germanium layer or whiskers; in this embodiment, the temperature of this zone is 750℃. c) Lower high-temperature melting zone 7: temperature is 940℃ ~ 1000℃ (this temperature is higher than the melting point of germanium); in this embodiment, the temperature of this zone is 985℃; The solid germanium layer grows downwards and melts when its end enters the lower high-temperature zone at 985°C. The annular tube bundle 1 runs from top to bottom through the entire middle medium-temperature deposition zone and extends into the lower high-temperature melting zone.

[0022] It should be noted that the structural design in this application enables the solid germanium deposited on the surface of the ring tube bundle to be melted into a liquid state once its end (root) enters the lower high-temperature melting zone during the process of growing downward along the tube bundle. S3. Product collection: At the bottom of the lower high-temperature melting zone, the collected liquid germanium droplets form a high-purity germanium melt pool, which is continuously discharged to the ingot casting process through the bottom melt outlet 9. S4. Tail Gas Treatment and Recirculation: The tail gas discharged from the bottom of the vertical reaction tube (mainly containing HCl, excess H2, unreacted GeCl4 and a small amount of GeCl2, etc.) is cooled by the condensation system and then absorbed by pure concentrated hydrochloric acid absorbent. The GeCl4 is returned to step S1 for recycling. The HCl in the tail gas is treated by absorption with pure concentrated hydrochloric acid absorbent. The unreacted hydrogen does not react with concentrated hydrochloric acid and is directly discharged into the air.

[0023] According to measurements, the method for producing high-purity germanium by reducing germanium tetrachloride with hydrogen in this embodiment has a single-pass conversion rate of 71.5% for germanium tetrachloride.

[0024] It should be noted that "single-pass conversion rate" is a core concept in chemical reaction engineering, specifically referring to the proportion of reactants that are converted into the target product in a single pass through the reactor in a continuous flow reaction system.

[0025] Single-pass conversion rate = (Amount of feed consumed in the reaction / Total amount of feed entering the reactor) × 100% Specifically, in this embodiment, hydrogen and germanium tetrachloride vapor are introduced from the top in one pass, flowing downwards and reacting. In this single pass, not all of the germanium tetrachloride reacts to form germanium. The single-pass conversion rate refers to the percentage of germanium tetrachloride consumed and converted into germanium in this single pass relative to the total amount introduced.

[0026] Example 2 This embodiment describes a method for producing high-purity germanium by reducing hydrogen with germanium tetrachloride. The main equipment is a quartz reaction tube, which has a diameter of 180 mm and a length of 1.5 m. The quartz reaction tube is arranged vertically, and multiple bundles of parallel annular tubes are arranged inside the quartz reaction tube. The annular tube bundles are composed of multiple concentrically arranged quartz tubes. The top of the quartz reaction tube is connected to a hydrogen inlet pipe and a GeCl4 vapor inlet pipe. A certain distance is left between the upper end face of the annular tube bundle and the top of the quartz reaction tube, so that this area serves as a pre-mixing zone for hydrogen and GeCl4 vapor. The method specifically includes the following steps: Hydrogen gas with a purity of 5N1 is preheated to 560℃; GeCl4 is heated to boil and form a gaseous state; then, inert gas is first introduced into the vertical quartz reaction tube to replace the gas in the vertical quartz reaction tube; then, H2 with a purity of 5N1 and GeCl4 vapor with a purity of 7N2 are introduced into the premixing zone of the quartz tube at a molar ratio of 8:1 for mixing.

[0027] First, inert gas is introduced into the vertical quartz reaction tube to replace the gas inside the tube. Then... The mixed gas descends into the main reaction zone under the influence of gravity and airflow. This main reaction zone contains multiple ring tube bundles extending axially along the reaction tube axis. The main reaction zone is divided into three temperature zones from top to bottom along the downward direction of the airflow: a) Upper high-temperature reaction zone: The temperature is 1000℃ ~ 1150℃. At this high temperature, the mixed gas undergoes a violent reduction reaction, mainly producing gaseous germanium. In this embodiment, the temperature of this zone is 1150℃. b) Mid-temperature deposition zone: The temperature is 600℃ ~ 850℃. High-temperature gaseous germanium from the upper part reaches a supersaturated state in this region, thus selectively condensing and depositing on the large surface of the ring tube bundle to form a solid germanium layer or whiskers; in this embodiment, the temperature of this zone is 820℃. c) Lower high-temperature melting zone: temperature is 940℃ ~ 1000℃ (this temperature is higher than the melting point of germanium); in this embodiment, the temperature of this zone is 940℃; The solid germanium layer grows downwards and melts when its end enters the lower high-temperature zone at 940°C. The annular tube bundle runs from top to bottom through the entire middle medium-temperature deposition zone and extends into the lower high-temperature melting zone.

[0028] S3. Product collection: At the bottom of the lower high-temperature melting zone, the collected liquid germanium droplets form a high-purity germanium melt pool, which is continuously discharged to the ingot casting process through the bottom melt outlet. S4. Tail Gas Treatment and Recirculation: The tail gas discharged from the bottom of the vertical reaction tube (mainly containing HCl, excess H2, unreacted GeCl4 and a small amount of GeCl2, etc.) is cooled by the condensation system and then absorbed by pure concentrated hydrochloric acid absorbent. The GeCl4 is returned to step S1 for recycling. The HCl in the tail gas is treated by absorption with pure concentrated hydrochloric acid absorbent. The unreacted hydrogen does not react with concentrated hydrochloric acid and is directly discharged into the air.

[0029] According to measurements, the method for producing high-purity germanium by reducing germanium tetrachloride with hydrogen in this embodiment has a single-pass conversion rate of 70.8% for germanium tetrachloride.

[0030] Example 3 This embodiment describes a method for producing high-purity germanium by reducing hydrogen with germanium tetrachloride. The main equipment is a quartz reaction tube, which has a diameter of 180 mm and a length of 1.5 m and is arranged vertically. Multiple bundles of parallel-arranged annular tubes are arranged inside the quartz reaction tube. Each annular tube is composed of multiple concentrically arranged quartz tubes. The top of the quartz reaction tube is connected to a hydrogen inlet pipe and a GeCl4 vapor inlet pipe. A certain distance is left between the upper end face of the annular tube bundle and the top of the quartz reaction tube, so that this area serves as a pre-mixing zone for hydrogen and GeCl4 vapor. The method specifically includes the following steps: Hydrogen gas with a purity of 5N2 is preheated to 600℃; GeCl4 is heated to boil and form a gaseous state; then, inert gas is first introduced into the vertical quartz reaction tube to replace the gas in the vertical quartz reaction tube; then, H2 with a purity of 5N2 and GeCl4 vapor with a purity of 7N2 are introduced into the premixing zone of the quartz tube at a molar ratio of 5:1 for mixing.

[0031] The mixed gas descends into the main reaction zone under the influence of gravity and airflow. This main reaction zone contains multiple ring tube bundles extending axially along the reaction tube axis. The main reaction zone is divided into three temperature zones from top to bottom along the downward direction of the airflow: a) Upper high-temperature reaction zone: The temperature is 1000℃ ~ 1150℃. At this high temperature, the mixed gas undergoes a violent reduction reaction, mainly producing gaseous germanium. In this embodiment, the temperature of this zone is 1000℃. b) Mid-temperature deposition zone: The temperature is 600℃ ~ 850℃. High-temperature gaseous germanium from the upper part reaches a supersaturated state in this region, thus selectively condensing and depositing on the large surface of the ring tube bundle to form a solid germanium layer or whiskers; in this embodiment, the temperature of this zone is 850℃. c) Lower high-temperature melting zone: temperature is 940℃ ~ 1000℃; in this embodiment, the temperature of this zone is 955℃; The solid germanium layer grows downwards and melts when its end enters the lower high-temperature zone at 955°C. The annular tube bundle runs from top to bottom through the entire middle medium-temperature deposition zone and extends into the lower high-temperature melting zone.

[0032] S3. Product collection: At the bottom of the lower high-temperature melting zone, the collected liquid germanium droplets form a high-purity germanium melt pool, which is continuously discharged to the ingot casting process through the bottom melt outlet. S4. Tail Gas Treatment and Recirculation: The tail gas discharged from the bottom of the vertical reaction tube (mainly containing HCl, excess H2, unreacted GeCl4 and a small amount of GeCl2, etc.) is cooled by the condensation system and then absorbed by pure concentrated hydrochloric acid absorbent. The GeCl4 is returned to step S1 for recycling. The HCl in the tail gas is treated by absorption with pure concentrated hydrochloric acid absorbent. The unreacted hydrogen does not react with concentrated hydrochloric acid and is directly discharged into the air.

[0033] According to measurements, the method for producing high-purity germanium by reducing germanium tetrachloride with hydrogen in this embodiment has a single-pass conversion rate of 71.3% for germanium tetrachloride.

[0034] Example 4 This embodiment describes a method for producing high-purity germanium by reducing hydrogen with germanium tetrachloride. The main equipment is a quartz reaction tube, which has a diameter of 180 mm and a length of 1.2 m and is arranged vertically. Multiple bundles of parallel-arranged annular tubes are arranged inside the quartz reaction tube. Each annular tube is composed of multiple concentrically arranged quartz tubes. The top of the quartz reaction tube is connected to a hydrogen inlet pipe and a GeCl4 vapor inlet pipe. A certain distance is left between the upper end face of the annular tube bundle and the top of the quartz reaction tube, so that this area serves as a pre-mixing zone for hydrogen and GeCl4 vapor. The method specifically includes the following steps: Hydrogen gas with a purity of 5N1 is preheated to 580℃; GeCl4 is heated to boil and form a gaseous state; then, inert gas is first introduced into the vertical quartz reaction tube to replace the gas in the vertical quartz reaction tube; then, H2 with a purity of 5N1 and GeCl4 vapor with a purity of 7N2 are introduced into the premixing zone of the quartz tube at a molar ratio of 7:1 for mixing.

[0035] The mixed gas descends into the main reaction zone under the influence of gravity and airflow. This main reaction zone contains multiple ring tube bundles extending axially along the reaction tube axis. The main reaction zone is divided into three temperature zones from top to bottom along the downward direction of the airflow: a) Upper high-temperature reaction zone: The temperature is 1000℃ ~ 1150℃. At this high temperature, the mixed gas undergoes a violent reduction reaction, mainly producing gaseous germanium. In this embodiment, the temperature of this zone is 1050℃. b) Mid-temperature deposition zone: The temperature is 600℃ ~ 850℃. High-temperature gaseous germanium from the upper part reaches a supersaturated state in this region, thus selectively condensing and depositing on the large surface of the ring tube bundle to form a solid germanium layer or whiskers; in this embodiment, the temperature of this zone is 600℃. c) Lower high-temperature melting zone: temperature is 940℃ ~ 1000℃; in this embodiment, the temperature of this zone is 950℃; The solid germanium layer grows downwards and melts when its end enters the lower high-temperature zone at 950°C. The annular tube bundle runs from top to bottom through the entire middle medium-temperature deposition zone and extends into the lower high-temperature melting zone.

[0036] S3. Product collection: At the bottom of the lower high-temperature melting zone, the collected liquid germanium droplets form a high-purity germanium melt pool, which is continuously discharged to the ingot casting process through the bottom melt outlet. S4. Tail Gas Treatment and Recirculation: The tail gas discharged from the bottom of the vertical reaction tube (mainly containing HCl, excess H2, unreacted GeCl4 and a small amount of GeCl2, etc.) is cooled by the condensation system and then absorbed by pure concentrated hydrochloric acid absorbent. The GeCl4 is returned to step S1 for recycling. The HCl in the tail gas is treated by absorption with pure concentrated hydrochloric acid absorbent. The unreacted hydrogen does not react with concentrated hydrochloric acid and is directly discharged into the air.

[0037] According to measurements, the method for producing high-purity germanium by reducing germanium tetrachloride with hydrogen in this embodiment has a single-pass conversion rate of 70.2% for germanium tetrachloride.

[0038] Those skilled in the art will know that improving one-way conversion rates has significant economic value, which can: 1. Reduced circulating load: A high single-pass conversion rate means less unreacted raw material in the tail gas exiting the reactor. This significantly reduces the equipment and energy burden of subsequent separation, recovery, and recompression cycles.

[0039] 2. Reduce equipment size and cost: For the same target output, a high single-pass conversion rate means that the amount of gas to be processed is smaller, and the reactor and related pipelines and equipment can be designed to be more compact.

[0040] As can be seen from Examples 1-4 of this application, the method in this application significantly improves the single-pass germanium tetrachloride conversion rate, which can stably reach more than 70%, which is more than double that of the conventional method.

[0041] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for producing high purity germanium by reduction of germanium tetrachloride with hydrogen, characterized by, The method comprises the following steps: S1. Raw material pretreatment and vaporization: vaporize germanium tetrachloride liquid to obtain germanium tetrachloride vapor, and preheat hydrogen to above 550℃; S2. Co-current and co-flow reduction and dynamic deposition-melting reaction: After gas replacement is performed in the vertical quartz reaction tube by introducing inert gas, the preheated hydrogen and germanium tetrachloride vapor are introduced from the top of the vertical quartz reaction tube and mixed in the mixing zone at the top of the vertical quartz reaction tube; The mixed gas flows downward into the reaction zone, and the reaction zone is provided with a ring tube bundle extending along the axial direction of the vertical quartz reaction tube, the ring tube bundle being composed of a plurality of concentrically arranged quartz tubes; the reaction zone is divided into three temperature zones from top to bottom along the gas flow direction: a) Upper high-temperature reaction zone: the temperature is 1000℃-1150℃, so that the mixed gas is reduced to generate gaseous germanium; b) Middle medium-temperature deposition zone: the temperature is 600℃-850℃, so that the gaseous germanium is condensed and deposited on the surface of the ring tube bundle to form solid germanium; c) Lower high-temperature melting zone: the temperature is 940℃-1000℃; The ring tube bundle extends through the middle medium-temperature deposition zone from top to bottom and extends into the lower high-temperature melting zone, so that the solid germanium deposited on the ring tube bundle is melted into liquid germanium at the end of the lower high-temperature melting zone during downward growth; S3. Product collection: at the bottom of the lower high-temperature melting zone, the liquid germanium dripping from the end of the lower high-temperature melting zone is collected to form a molten pool, and is continuously or intermittently discharged; S4. Tail gas treatment and circulation: the tail gas discharged from the bottom of the vertical quartz reaction tube is treated by condensation, and the germanium tetrachloride therein is separated and recovered and returned to step S1; the hydrogen chloride in the tail gas is absorbed by hydrochloric acid absorption liquid; the remaining hydrogen after separation is partially or entirely returned to step S1 for recycling.

2. The method for producing high purity germanium by reduction of germanium tetrachloride with hydrogen according to claim 1, wherein The molar ratio of the hydrogen to the germanium tetrachloride vapor is 5-10:

1.

3. The method for producing high purity germanium by reduction of germanium tetrachloride with hydrogen according to claim 1, wherein The purity of the hydrogen is not less than 99.999%, and the purity of the germanium tetrachloride is not less than 99.99999%.

4. The method for producing high purity germanium by reduction of germanium tetrachloride with hydrogen according to claim 1, wherein The diameter of the vertical quartz tube is 150-200mm, and the length is 1-1.5m.

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