Method and device for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste

Abstract

The present invention provides a method and device for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste. The method comprises the following steps: S1, purifying the arsenic-containing hazardous waste to obtain crude arsenic of the first purity; S2, mixing the crude arsenic of the first purity, a first reducing agent and a purifying agent, and performing sublimation in a high-vacuum environment to obtain crude arsenic of the second purity; S3, mixing the crude arsenic of the second purity with a metal material and performing a melting reaction under high-vacuum conditions to prepare a metal arsenide; S4, reacting the metal arsenide with an acid solution to generate a gaseous arsenide; S5, performing deep purification on the gaseous arsenide through multi-stage impurity removal to obtain an electronic-grade gaseous arsenide; S6, pyrolyzing and condensing the electronic-grade gaseous arsenide to obtain high-purity arsenic. This method utilizes arsenic-containing hazardous waste, not only reducing the environmental arsenic pollution problem in the non-ferrous industry, but also significantly improving the purity and economic value of arsenic products, having great economic value and application prospects.

Description

Technical Field

[0001] The present invention relates to the field of treatment of arsenic-containing hazardous waste and preparation of high-purity arsenic, and particularly to a complete set of preparation methods and devices for preparing high-purity arsenic from arsenic sulfide slag. Background Art

[0002] Arsenic, as an important semiconductor material, plays an indispensable role in the electronics industry. Especially in the fields of semiconductor devices, optoelectronic materials, gas-phase doping, and preparation of high-purity arsenic products, the purity of arsenic has a decisive impact on its performance. However, traditional arsenic preparation processes have many limitations, especially in terms of purity, environmental protection, and economic benefits.

[0003] First of all, traditional arsenic preparation methods often fail to meet the high-purity requirements of electronic-grade arsine. In the semiconductor manufacturing process, high-purity arsine (AsH3) is a key doping source, and its purity directly affects the performance and reliability of devices. Existing arsine preparation processes, such as direct extraction from arsenic ores or preparation by chemical synthesis methods, are often accompanied by complex side reactions and introduction of impurities, resulting in insufficient purity of the final product. The treatment and utilization of arsenic-containing hazardous waste have become an urgent problem to be solved. During the smelting process of non-ferrous metals, a large amount of arsenic-containing waste slag, such as arsenic sulfide slag, is generated. If these waste slags are not properly treated, they will cause serious environmental pollution. Therefore, developing a method for extracting high-purity arsenic from arsenic-containing hazardous waste can not only reduce environmental pollution but also realize the recycling of resources. In addition, existing arsenic preparation processes also have deficiencies in energy consumption and equipment requirements. Many processes require harsh conditions such as high temperature and high pressure, resulting in high energy consumption and high costs. In addition, complex process flows also increase the equipment investment and maintenance costs, restricting the large-scale production and application of arsenic products. Summary of the Invention

[0004] The present invention aims to provide a method and device for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste. This method can effectively extract high-purity arsenic from arsenic-containing hazardous waste such as arsenic sulfide slag, not only reducing the environmental arsenic pollution problem in the non-ferrous industry but also significantly improving the purity of arsenic products and enhancing the resource recycling efficiency.

[0005] The present application provides a method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, comprising the following steps:

[0006] S1, purifying the arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0007] S2, mixing the crude arsenic of the first purity, a first reducing agent, and a purifying agent, and performing sublimation in a high-vacuum environment to obtain crude arsenic of the second purity.

[0008] S3. Mix the second-purity crude arsenic with metal materials and conduct a melting reaction under high vacuum conditions to prepare metal arsenide.

[0009] S4. React the metal arsenide with an acid solution to generate gaseous arsenide.

[0010] S5. Deeply purify the gaseous arsenide through multi-stage impurity removal to obtain electronic-grade gaseous arsenide.

[0011] S6. Pyrolyze and condense the electronic-grade gaseous arsenide to obtain high-purity arsenic.

[0012] This application also provides a device for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, which is used to implement the method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste. The device for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste includes:

[0013] The first-purity crude arsenic preparation mechanism is used to purify the arsenic-containing hazardous waste to obtain the first-purity crude arsenic.

[0014] The second-purity arsenic preparation mechanism is used to mix the first-purity crude arsenic, the first reducing agent, and the purification agent, and conduct sublimation in a high-vacuum environment to obtain the second-purity crude arsenic.

[0015] The metal arsenide preparation mechanism is used to mix the second-purity crude arsenic with metal materials and conduct a melting reaction under high vacuum conditions to prepare metal arsenide.

[0016] The gaseous arsenide preparation mechanism is used to react the metal arsenide with an acid solution to generate gaseous arsenide.

[0017] The electronic-grade gaseous arsenide preparation mechanism is used to deeply purify the gaseous arsenide through multi-stage impurity removal to obtain electronic-grade gaseous arsenide.

[0018] The high-purity arsenic preparation mechanism is used to pyrolyze and condense the electronic-grade gaseous arsenide to obtain high-purity arsenic.

[0019] Advantages of the present invention:

[0020] In the above method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, arsenic sulfide slag is successively prepared to obtain the first-purity crude arsenic, the second-purity crude arsenic, metal arsenide, gaseous arsenide, and electronic-grade gaseous arsenide, and finally high-purity arsenic is obtained. The process flow adopted by the present invention is not only simple in operation and easy to realize industrial production, but also reduces material loss and energy consumption. The obtained high-purity arsenic can be widely used in the preparation of high-purity arsenide semiconductor material products and other fields, meeting the urgent needs of industries such as semiconductor electronic devices for high-quality raw materials. Description of the Drawings

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0022] Figure 1 It is a diagram of the elemental quantitative analysis results of the first-purity crude arsenic in Embodiment 1 of the present invention;

[0023] Figure 2 It is a diagram of the determination of the total elemental content of the first-purity crude arsenic in Embodiment 1 of the present invention;

[0024] Figure 3 It is an XRD phase analysis diagram of the first-purity crude arsenic in Embodiment 1 of the present invention;

[0025] Figure 4 It is a diagram of the determination of the total elemental content of the second-purity crude arsenic prepared in Embodiment 6 of the present invention;

[0026] Figure 5 It is a phase result diagram of the metal arsenide prepared in some embodiments and comparative examples of the present invention. Among them, Figure 5 (a) is a phase analysis diagram of the metal arsenide product prepared in Embodiment 7, Figure 5 (b) is a phase analysis diagram of the metal arsenide product prepared in Comparative Example 5, Figure 5 (c) is a phase analysis diagram of the metal arsenide product prepared in Embodiment 9, Figure 5 (d) is a phase analysis diagram of the metal arsenide product prepared in Embodiment 10;

[0027] Figure 6 It is a schematic diagram of the liquid inlet device (metering pump + pneumatic ball valve) in Embodiments 15-17 and Comparative Examples 11-13 of the present invention. Among them, 10 is the first pneumatic ball valve, 20 is the metering pump, and 30 is the second pneumatic ball valve;

[0028] Figure 7 It is a schematic flow diagram of the method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste of the present invention;

[0029] Figure 8 It is a schematic operation flow diagram of Embodiments 19-27 of this application;

[0030] Figure 9 It is a schematic structural diagram of the rectification mechanism of this application;

[0031] Figure 10 It is a schematic operation flow diagram of Embodiments 28-35.

[0032] The realization, functional features, and advantages of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific Embodiments

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

[0034] Moreover, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0035] To achieve the above object, the present invention provides a method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, and the specific steps include:

[0036] This application provides a method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, referring to Figure 7 , including the following steps:

[0037] S1. Purify the arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0038] S2. Mix the crude arsenic of the first purity, the first reducing agent, and the purifying agent, and perform sublimation in a high-vacuum environment to obtain crude arsenic of the second purity.

[0039] S3. Mix the crude arsenic of the second purity with metal materials and perform a melting reaction under high-vacuum conditions to prepare metal arsenide.

[0040] S4. React the metal arsenide with an acid solution to generate gaseous arsenide.

[0041] S5. Deeply purify the gaseous arsenide through multi-stage impurity removal to obtain electronic-grade gaseous arsenide.

[0042] S6. Pyrolyze and condense the electronic-grade gaseous arsenide to obtain high-purity arsenic.

[0043] In the above method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, arsenic sulfide slag is successively prepared into crude arsenic of the first purity, crude arsenic of the second purity, metal arsenide, gaseous arsenide, and electronic-grade gaseous arsenide, and finally high-purity arsenic is obtained. The technological process adopted in the present invention is not only simple to operate and easy to realize industrial production, but also reduces material loss and energy consumption. The obtained high-purity arsenic can be widely used in fields such as gas-phase doping and the preparation of high-purity arsenic products, meeting the urgent needs of industries such as electronic devices and semiconductor materials for high-quality raw materials.

[0044] The following will respectively give a detailed description of each step of S1~S6.

[0045] The first part gives a detailed description of step S1.

[0046] S1. Purify the arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0047] There are various ways to purify the arsenic-containing hazardous waste. For example, the arsenic-containing hazardous waste can be purified by mixing it with iron powder and roasting.

[0048] The arsenic-containing hazardous waste includes arsenic sulfide slag, and also includes arsenic-containing waste residues such as arsenic soot and arsenic alkali slag. The following mainly takes arsenic sulfide slag as an example for description.

[0049] To improve the purification effect, the arsenic-containing hazardous waste is subjected to some pretreatment before roasting, such as drying and crushing.

[0050] In some embodiments, the moisture content of the arsenic sulfide slag is 40%~80%, and the drying step controls the temperature between 70°C and 110°C to remove the free water and bound water in the arsenic sulfide slag.

[0051] In some embodiments, the arsenic sulfide slag is dried at 90°C to optimize the moisture removal efficiency.

[0052] The dried arsenic sulfide slag is crushed to 100~200 meshes to increase the reaction surface area. In some embodiments, the arsenic sulfide slag is crushed to 150 meshes to balance the reaction efficiency and energy consumption.

[0053] Among them, the roasting step is carried out in a closed container, and the closed container has a reaction zone and a material receiving zone. The reaction zone is the reaction area of the mixture of arsenic-containing hazardous waste and iron powder. The material receiving zone is the generation area of crude arsenic of the first purity. The roasting temperature in the reaction zone is 550~700°C, and the roasting temperature in the material receiving zone is 300~500°C to remove the organic sulfur and other volatile impurities in the arsenic sulfide slag.

[0054] The second part gives a detailed description of step S2.

[0055] S2. Mix the crude arsenic of the first purity, the first reducing agent, and the purification agent, and carry out sublimation in a high-vacuum environment to obtain crude arsenic of the second purity.

[0056] In some embodiments, the step of mixing the first-purity crude arsenic, the first reducing agent, and the purification agent and performing sublimation in a high-vacuum environment to obtain the second-purity crude arsenic specifically includes the following steps:

[0057] S21. Mix and proportion the first-purity crude arsenic, the first reducing agent, and the purification agent to obtain a mixed arsenic material.

[0058] In some embodiments, the particle size of the first-purity crude arsenic can be 0.5 - 3 cm, and the purity of the first-purity crude arsenic can be of 2N grade. The 2N-grade first-purity crude arsenic is crude arsenic with an impurity content ≤ 0.1% and > 0.01%. In some embodiments, elemental quantitative analysis is performed on the first-purity crude arsenic. In the first-purity crude arsenic, the Sb content can reach 1000 - 1500 ppm, which is the impurity element with the highest content. Other impurity elements include Si, S, and B, with contents of 40 - 60 ppm, 4 - 5 ppm, and 1 - 2 ppm respectively.

[0059] The first-purity crude arsenic also includes a certain content of oxygen element. In some embodiments, the oxygen content (mass fraction) of the first-purity crude arsenic is 5 - 10%.

[0060] In some embodiments, the first reducing agent includes one or more of zinc powder, iron powder, and carbon powder. The addition amount of the first reducing agent is 1% - 5% of the mass of the first-purity crude arsenic. In some embodiments, the particle size of the first reducing agent can be 200 mesh.

[0061] In some embodiments, the purification agent includes one or more of copper powder, cadmium powder, lead powder, and sulfuric acid. The addition amount of the purification agent can be 2 - 10% of the mass of the first-purity crude arsenic.

[0062] In some embodiments of the present invention, when the purification agent is sulfuric acid, the concentration of sulfuric acid can be 90 - 95%.

[0063] In some other embodiments of the present invention, the purification agent can include copper powder and / or sulfuric acid.

[0064] When some purification agents and the first reducing agent are used in combination, they have a synergistic effect and have a better effect than general purification agents and the first reducing agent. In some embodiments, the first reducing agent can be one of carbon powder, zinc powder, and iron powder, and the purification agent can be one of copper powder and sulfuric acid.

[0065] In some preferred embodiments, the first reducing agent can be one of carbon powder and iron powder, and the purification agent can be copper powder.

[0066] In some more preferred embodiments, the first reducing agent is carbon powder and the purification agent is copper powder.

[0067] In some more preferred embodiments, the first reducing agent is carbon powder and the purifying agent is sulfuric acid.

[0068] In the present invention, the first-purity crude arsenic is mixed and proportioned with the first reducing agent. On the one hand, it avoids the negative impact of oxidized impurities (such as arsenic oxides in high valence states) on the sublimation efficiency of arsenic and the purity of the product. The addition of an appropriate amount of the first reducing agent can reduce these oxidized impurities to low-valence arsenic that is more easily sublimated, so that the purification of arsenic is relatively thorough. On the other hand, the first reducing agent can create a reducing atmosphere to ensure that arsenic is not oxidized during the sublimation process.

[0069] And purifying agents such as copper powder and cadmium powder effectively separate these impurities from arsenic by forming non-volatile compounds with sulfur. These compounds remain in the solid residue during the sublimation process, preventing the volatilization of impurities. The use of the purifying agent also enhances the chemical stability of the system, avoids the occurrence of side reactions, and ensures the specificity and efficiency of the purification process.

[0070] In some embodiments, the addition amount of the first reducing agent can be 1% - 5% of the mass of the first-purity crude arsenic.

[0071] S22. Place the mixed arsenic material in a closed first high-vacuum environment. The first high-vacuum environment includes a hot end and a cold end. The mixed arsenic material sublimes at the hot end and condenses at the cold end, and the second-purity crude arsenic is collected. The vacuum pressure in the first high-vacuum environment is not greater than 1 Pa.

[0072] It should be noted that in the present invention, the vacuum pressure and the degree of vacuum have the same meaning, that is, it represents the specific pressure value of the gas in the vacuum environment.

[0073] In some embodiments, the degree of vacuum in the first high-vacuum environment is 0.001 - 0.1 Pa.

[0074] The main impurity of the first-purity crude arsenic is antimony. Since arsenic and antimony belong to Group VA elements and have similar chemical properties, it is difficult to separate them under conventional conditions. However, by controlling the reaction temperature under high-vacuum conditions and using the significant difference in the saturated vapor pressure and the maximum evaporation rate between arsenic and antimony under high-vacuum and low-temperature conditions, the residual amount of antimony can be effectively reduced. At a suitable reaction temperature, the evaporation rate of arsenic is significantly higher than that of antimony, so that arsenic can preferentially sublime to the cold end, improving the purity of the product, which reflects the innovation of the present invention.

[0075] The calculation formula for the saturated vapor pressure of each metal is:

[0076] log 10 P = A T -1 + B log 10 T+ C T + D

[0077] The saturated vapor pressures of various metals calculated according to the above formula are shown in Table 1 as follows:

[0078] Table 1 Saturated Vapor Pressures of Various Metals

[0079]

[0080] The present invention adopts a high-vacuum technology. For example, the vacuum degree in the vacuum environment is controlled to be no greater than 1 Pa, and the separation of arsenic and the main impurity antimony is achieved by utilizing the differences in saturated vapor pressure, volatilization rate and boiling point between them, effectively alleviating the problem of difficult separation of impurities during the sublimation process of first-purity crude arsenic, thereby obtaining high-purity arsenic, i.e., second-purity crude arsenic.

[0081] The high-vacuum environment provides a preparation condition with almost no interference from gas molecules, which helps to reduce the introduction of impurities and improve the purification efficiency. Under high-vacuum conditions, elemental arsenic can be purified through the sublimation process, in which the solid substance directly transforms into a gaseous state without passing through the liquid state; in the high-vacuum environment, due to the reduction of the interference of gas molecules on the sublimation process, the sublimation process can proceed more effectively.

[0082] During the purification process, elemental arsenic is heated to the sublimation point, and arsenic molecules will detach from the solid surface and enter the vacuum environment. Due to the different sublimation temperatures of arsenic and antimony, by precisely controlling the temperature of the hot end, the separation of arsenic and antimony can be achieved. In addition, the high-vacuum environment also helps to reduce the oxidation and hydrolysis of arsenic during the sublimation process, thus ensuring the chemical purity of the second-purity crude arsenic. The high-vacuum sublimation purification technology combined with precise temperature control and atmosphere management provides a new approach for the preparation of high-purity elemental arsenic, which can not only improve the purity of elemental arsenic, but also reduce the by-products and operation risks during the preparation process, and is of great significance for promoting the development of semiconductor material technology.

[0083] In some specific embodiments, the first-purity crude arsenic, the first reducing agent, and the purification agent can be placed in an inert atmosphere in proportion and sufficiently ground and mixed by a mixer to obtain a mixed arsenic material, and then the mixed arsenic material is placed in a vacuum container, evacuated to 0.001 - 0.1 Pa by sealing and then placed in a furnace body structure with a hot end and a cold end for sublimation.

[0084] In some embodiments, the temperature of the hot end is 600 - 900 °C, and the temperature difference between the hot end and the cold end is not less than 200 °C; the temperature of the cold end is 400 - 700 °C. Among them, when the temperature of the cold end is lower than 300 °C, the adsorption energy is too low, and it is difficult for arsenic gas molecules to adhere to the cold-end medium.

[0085] In some specific embodiments, the temperature of the hot end can be 600 - 800 °C, and the temperature of the cold end can be 400 - 600 °C. In some more specific embodiments, the temperature of the hot end can be 600 - 700 °C, and the temperature of the cold end can be 400 - 500 °C.

[0086] Exemplarily, in a situation where the vacuum degree is 0.001 Pa, the temperature of the hot end is set to 650 °C, and the temperature of the cold end is 450 °C.

[0087] In the present invention, the sublimation duration of the hot end is not less than 2 h; further, the sublimation duration of the hot end can be 2 - 8 h; exemplarily, the sublimation duration of the hot end can be 6 - 8 h.

[0088] The step of sublimating the mixed arsenic material at the hot end and condensing it at the cold end, and collecting the second - purity crude arsenic further includes transferring the second - purity crude arsenic to an inert atmosphere and successively performing crushing treatment on the second - purity crude arsenic; wherein, the duration of the crushing treatment is 5 - 30 min, and the particle size for screening is 200 - 400 mesh.

[0089] The inert atmosphere can be one of nitrogen or argon. The crushing process is to crush the material using a crushing and grinding machine to obtain purified arsenic powder through screening.

[0090] The crushing process can be to crush the material using a crushing and grinding machine to obtain purified arsenic powder through screening. The crushing time is 5 - 30 min, and the particle size for screening can be 200 - 400 mesh.

[0091] The method in step S2 of the present invention has high impurity - removal efficiency and deoxidation performance. By precisely controlling the ratio of additives and reaction conditions, high - purity second - purity crude arsenic can be prepared on a large scale to meet the market demand for high - quality arsenic products. At the same time, the standardized process of this method is also convenient for implementation in industrial production, ensuring the consistency and reliability of product quality.

[0092] The third part introduces step S3 in detail.

[0093] S3: Mix the second - purity crude arsenic with metal materials and carry out a melting reaction under high - vacuum conditions to prepare metal arsenide.

[0094] In some embodiments, the step of mixing the second - purity crude arsenic with metal materials and carrying out a melting reaction under high - vacuum conditions to prepare metal arsenide includes:

[0095] S31: Mix and proportion the second - purity crude arsenic with metal materials to obtain an arsenic - metal mixture.

[0096] Among them, the metal material is active metal powder, and the metal material includes one of magnesium powder, zinc powder, and aluminum powder. Hereinafter, taking the metal material as zinc powder as an example for illustration.

[0097] In some embodiments, the mass ratio of the second-purity crude arsenic to the metal material is 1:1.3 to 1:1.8. Exemplarily, the mass ratio of the second-purity crude arsenic to the zinc material is 1:1.3 to 1:1.8. In the case where the metal material is zinc material, by precisely controlling the arsenic-to-metal ratio and combining with the application of a vacuum environment, the efficient generation of Zn3As2 can be promoted, and the generation of by-products As2O3 and ZnAs2 can be avoided. The vacuum condition (0.001 - 1 Pa) significantly reduces the oxygen content in the environment, inhibits the formation of oxides such as As2O3, and at the same time enhances the vapor pressure of arsenic, making it easier for arsenic to react with active metals to form Zn3As2. The appropriate arsenic-to-metal ratio can fully play its role in the vacuum environment, effectively controlling the reaction selectivity, improving the generation rate and purity of Zn3As2, so as to achieve the purpose of optimizing product quality.

[0098] In some specific embodiments, the mass ratio of the second-purity crude arsenic to the zinc material can be 1:1.3.

[0099] In some specific embodiments, the second-purity crude arsenic and the zinc material can be placed in an inert atmosphere in proportion, and the arsenic-zinc mixture can be obtained by fully grinding and mixing through a mixer.

[0100] S32. Place the arsenic-metal mixture in a vacuum container, heat the vacuum container to not less than 750 °C for a melting reaction to obtain metal arsenide; the vacuum degree in the vacuum container is 0.001 - 1 Pa (i.e., the second vacuum environment), and the reaction time of the melting reaction is not less than 5 hours.

[0101] In the present invention, before or during the melting reaction, a second reducing agent can be added to the arsenic-metal mixture to control the participation of the second reducing agent in the melting reaction; specifically, the second reducing agent can be added to the arsenic-metal mixture before the melting reaction; for example: after mixing the second reducing agent and the arsenic-metal mixture, they are placed in the vacuum container together for the melting reaction.

[0102] In some embodiments of the present invention, the second reducing agent includes one or more of activated carbon, carbon black, and graphite powder; the addition amount of the second reducing agent is 0.1 - 0.5% of the mass of the crude arsenic.

[0103] In some specific embodiments of the present invention, the second reducing agent can include activated carbon and / or graphite powder.

[0104] Exemplarily, the vacuum container can be heated to 600-1000°C for the melting reaction to obtain metal arsenide.

[0105] In some embodiments, the degree of vacuum in the second vacuum environment can be 0.001-1 Pa, belonging to a vacuum environment.

[0106] In some embodiments, the degree of vacuum of the vacuum container in the second vacuum environment can be 0.001-0.01 Pa to further reduce the oxygen content to improve the product purity.

[0107] In the present invention, the temperature of the melting reaction carried out in the second vacuum environment is not lower than 750°C. In some embodiments, the temperature of the melting reaction can be 750-1200°C; in some specific embodiments, the temperature of the melting reaction can be 750-1100°C; in some more specific embodiments, the temperature of the melting reaction can be 750-1050°C.

[0108] In some preferred embodiments of the present invention, the temperature of the melting reaction can also be controlled at 750-950°C. Through thermodynamic analysis, it can be seen that when the temperature of the melting reaction is 750-950°C, the phase structure of the Zn3As2 system changes significantly. Especially at a temperature near 800°C, the α-phase and β-phase of Zn3As2 will transform, thereby optimizing the reaction process. The β-phase has higher stability and stronger reaction activity than the α-phase, which can effectively increase the reaction rate of arsenic and zinc and promote the formation of metal arsenide. In addition, due to the β-phase having a more compact crystal structure, the doping of impurities is reduced. Therefore, using the phase transformation process near this temperature to prepare metal arsenide can also effectively improve its purity. Considering the temperature, reaction rate, and phase transformation characteristics in the phase diagram comprehensively, too low a temperature (<750°C) results in low reaction efficiency and no phase change effect, making it difficult to prepare high-quality zinc arsenide products.

[0109] In some other preferred embodiments of the present invention, the temperature of the melting reaction can be controlled at 750-850°C to maximize the separation of arsenic and antimony by taking advantage of the significant difference in the saturated vapor pressure and maximum evaporation rate between arsenic and antimony, so that the antimony content in the metal arsenide product is close to zero. It should be noted that since arsenic and antimony both belong to Group V A elements and have similar chemical properties, it is difficult to separate them under conventional conditions, increasing the complexity of purification.

[0110] Exemplarily, the temperature of the melting reaction can be controlled at 770-830°C; additionally exemplarily, the temperature of the melting reaction can also be controlled at 780-820°C.

[0111] The reaction time of the melting reaction in step S3 is not less than 5 hours. For example, the duration of the melting reaction can be 5-12 h.

[0112] According to the morphological distinction of the whole-process metal arsenide, the metal arsenide includes a metal arsenide melt, a metal arsenide bulk, and a metal arsenide particulate product. Specifically: in step S3, the metal arsenide melt obtained from the melting reaction is cooled to obtain a metal arsenide bulk, and the metal arsenide bulk is crushed and screened in an inert gas atmosphere to obtain a particulate product of the metal arsenide; the particle size of the particulate product of the metal arsenide can be 200-400 mesh.

[0113] Exemplarily, the crushing method includes ball milling, the duration of the ball milling is 6-12 h, and the particle size of the screening is 200-400 mesh.

[0114] Also exemplarily, the inert gas includes one of nitrogen or argon.

[0115] The purity of the metal arsenide product prepared by the present invention is 3N, the antimony content is not detected by energy spectrum, and the crystal structure conforms to the standard Zn3As2 sample card.

[0116] The fourth part details step S4.

[0117] S4, reacting the metal arsenide with an acid solution to generate a gaseous arsenide.

[0118] In some embodiments, the step of reacting the metal arsenide with an acid solution to generate a gaseous arsenide includes:

[0119] The metal arsenide is mixed with sulfuric acid in a third vacuum environment, and a gaseous arsenide is obtained through a gas generation reaction. The gaseous arsenide includes arsine.

[0120] The sulfuric acid used in the present invention exists in the form of a sulfuric acid solution, and its concentration can be 5-20%; in the examples and comparative examples, the sulfuric acid is provided in the form of a sulfuric acid solution, and the concentration is basically 9-11%.

[0121] In some embodiments, the vacuum degree of the third vacuum environment is 1-100 Pa.

[0122] In some embodiments, the formation of the third vacuum environment includes the steps of:

[0123] S41, evacuating the device for the gas generation reaction, and then introducing an inert gas into the device to normal pressure.

[0124] S42, repeating step S41 at least 2 times, such as 2-4 times.

[0125] S43, evacuating the device at normal pressure to 1-100 Pa to obtain the third vacuum environment. The inert gas can include nitrogen or argon.

[0126] After evacuation, nitrogen or argon is filled until the normal pressure is reached, and this process is repeated several times to ensure the stability of the reaction system. Finally, the system is evacuated to a vacuum environment of 1 - 100 Pa, enabling the gas generation reaction to proceed under the most ideal conditions and effectively suppressing the occurrence of side reactions.

[0127] Exemplarily, the vacuum degree in the device for the gas generation reaction can be evacuated to 1 - 50 Pa.

[0128] In some embodiments, during the gas generation reaction, the addition rate of sulfuric acid is 50 - 200 mL / min, and the generation rate of arsine is 1 - 3 L / min; during the implementation process, the duration of the gas generation reaction can be 30 - 120 min, preferably 40 - 80 min.

[0129] In some other embodiments, sulfuric acid can be added to the third vacuum environment through a liquid inlet device.

[0130] The liquid inlet device can include a metering pump. The amount of sulfuric acid added can be adjusted by controlling the stroke length of the metering pump, and the addition rate of sulfuric acid is controlled between 50 - 200 mL / min, thereby achieving precise control of the reaction rate and adjusting the generation rate of arsine (gaseous arsenic compound) to 1 - 3 L / min.

[0131] As Figure 6 shown, the liquid inlet device can also be a combined device of a metering pump and a pneumatic ball valve. Among them, 10 is the first pneumatic ball valve, 20 is the metering pump, and 30 is the second pneumatic ball valve.

[0132] In some embodiments, the generated arsine in the gas generation reaction is subjected to water treatment, including the steps of: passing the arsine into a drying and water removal device, where the temperature of the drying and water removal device is set at 0 - 100 °C, further 50 - 100 °C. Through the drying and water removal device, the water content in the arsine is effectively reduced to the lowest level, obtaining relatively pure crude arsine gas, which is suitable for subsequent purification to prepare electronic-grade high-purity arsine.

[0133] In some other embodiments, a negative pressure device is provided between the third vacuum environment and the drying and water removal device. The negative pressure device is used to suck the arsine gas in the third vacuum environment to maintain the vacuum degree of the third vacuum environment. The negative pressure device is used to enhance the gas generation reaction trend, enabling the gas generation reaction to proceed to completion. Exemplarily, the negative pressure device can be a Venturi negative pressure device.

[0134] In comparison, in the traditional process, the vacuum state during the gas generation reaction cannot be maintained, which inhibits the forward progress of the gas generation reaction.

[0135] In some embodiments, the gas generation reaction parameters are controlled as shown in Table 2:

[0136] Table 2 Parameter Control during the Gas Generation Reaction

[0137]

[0138] That is, in some embodiments, in the gas generation reaction system of metal arsenide and sulfuric acid (i.e., the reaction solution formed by sulfuric acid and metal arsenide), the concentration of metal arsenide can be 0.1 - 0.5 mol / L; the temperature of the gas generation reaction can be 20 - 40 °C, the pH in the gas generation reaction system can be 0.2 - 1, the duration of the gas generation reaction can be 30 - 120 min, and the reaction pressure of the gas generation reaction can be 1 - 100 Pa.

[0139] In summary, in step S4 of the present invention, the reaction process of metal arsenide and sulfuric acid is synergistically optimized by uniquely adopting vacuum environment maintenance, precise control of reaction parameters, and drying and water removal techniques.

[0140] Specifically, first, a low vacuum environment is conducive to the volatilization of arsine gas. Arsine has a low boiling point and is prone to decomposition or reaction with other substances under normal pressure. A low vacuum can reduce the partial pressure of gas in the reactor, enabling arsine to volatilize rapidly and escape from the reaction area, avoiding the mixing of arsine with other components in the reaction system (such as sulfuric acid gas or other impurity gases) and reducing the occurrence of side reactions. Moreover, a low vacuum helps reduce the generation of impurities. When the reaction is carried out under a low vacuum, external air is effectively isolated, preventing the oxidation reaction of arsine with oxygen in the air during generation, thereby reducing the formation of arsenic oxide or other oxides and ensuring the purity of arsine.

[0141] In addition, a low vacuum is conducive to accelerating the reaction rate. Under a low vacuum, the collisions between gas molecules are more frequent, and the exchange of reactants and products is more rapid, thus enhancing the reaction efficiency. That is, the third vacuum environment significantly reduces the moisture and oxygen concentrations in the reaction environment, reduces unnecessary side reactions, and ensures that the reaction between metal arsenide and sulfuric acid can proceed fully and effectively. Based on this, maintaining the third vacuum environment ensures the positive trend of the gas generation reaction. Secondly, precise control of reaction parameters can regulate the reaction process and improve the yield and purity of arsine.

[0142] Finally, the setting of the drying and water removal device further reduces the moisture content in the generated arsine, laying a foundation for the subsequent preparation of high-purity arsine. This new type of efficient preparation method can overcome many drawbacks in traditional processes, significantly improve the yield and purity of arsine, effectively improve the quality and reaction efficiency of arsine, and is particularly suitable for the large-scale production requirements of the semiconductor industry, thus having high industrial application value and providing a more economical and efficient route for the production of electronic-grade arsine.

[0143] The fifth part introduces step S5 in detail.

[0144] S5. Deeply purify the gaseous arsenide through multi-stage impurity removal to obtain electronic-grade gaseous arsenide.

[0145] In some embodiments, the step of deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic-grade gaseous arsenide includes:

[0146] S51: Place the gaseous arsenide under the conditions of a first temperature and a first pressure and perform rectification in a rectification mechanism, collect the gaseous substance to obtain arsine with a first purity.

[0147] Exemplarily, the first temperature is -80°C to -10°C. The first pressure is 0.1 MPa to 0.6 MPa. For example, the pressure range of the first pressure is 0.4 MPa to 0.6 MPa.

[0148] In some embodiments, a low-pressure condensation rectification device is used. This device contains a de-light tower and a de-heavy tower. By regulating the top and bottom temperatures of the de-light tower, since the boiling point of the light-component gaseous substance is lower than that of arsine, the light-component gaseous substance is volatile and exists at the top of the de-light tower. Separate the light-component gaseous substance to obtain a liquid substance, and collect it through a first gaseous recovery device. The liquid substance is at the bottom of the de-light tower and is collected through a first liquid recovery device.

[0149] In still other embodiments, the boiling point of the light-component gaseous substance is lower than that of arsine, and it is also called low-boiling-point impurities, including methane, ethane or silane.

[0150] In some embodiments, after separating the light-component gaseous substance through the de-light tower, a liquid substance is obtained. Then, the liquid substance is sent into the de-heavy tower. By regulating the top and bottom temperatures of the de-heavy tower, since the boiling point of the heavy-component substance is higher than that of arsine, the heavy-component substance is liquefied into a heavy-component liquid substance and exists at the bottom of the de-heavy tower. Separate the heavy-component liquid substance to obtain arsine gas with a first purity. Among them, the arsine gas with a first purity is at the top of the de-heavy tower and is collected with a first collector. The heavy-component liquid substance is at the bottom of the de-heavy tower and is collected through a second liquid recovery device.

[0151] In still other embodiments, the boiling point of the heavy-component substance is higher than that of arsine, and it is also called high-boiling-point impurities, including stibine.

[0152] S52: Pass the arsine with the first purity through an adsorbent at a second temperature to remove gas impurities and dry it to obtain arsine with a second purity.

[0153] In some embodiments, in the step of passing the arsine with the first purity through an adsorbent at a second temperature, the second temperature is 50°C to 80°C.

[0154] In some embodiments, the adsorbent is at least one of a pore-adjusted carbon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve, and activated alumina. By selectively adsorbing different molecules through the microporous structure of the adsorbent, small-molecule kinetic diameter impurities (such as hydrogen sulfide, hydrogen, etc.) in arsine can be effectively removed, significantly reducing the residual impurity content in arsine.

[0155] The boiling points of hydrogen sulfide and arsine are close, but their molecular kinetic diameters differ greatly. Therefore, by passing the first-purity arsine through the adsorbent at the second temperature, impurities in the first-purity arsine, such as hydrogen sulfide and volatile organic compounds, are removed to prevent the impurities from clogging the pipeline in subsequent steps and affecting the purification efficiency of gaseous arsine substances. In addition, this operation can also dry the gas to obtain the second-purity arsine. At the same time, the adsorbent at the second temperature can also synchronously activate other thermodynamically unstable impurities.

[0156] Under the condition of the second temperature within the above temperature range, on the one hand, the adsorption effect of the adsorbent is improved, and energy consumption can also be reduced. Because the molecules adsorbed on the adsorbent are more likely to escape into the gas phase due to the intensified thermal motion, thereby increasing the adsorption rate of the adsorbent. On the other hand, this temperature has a suitable temperature difference from the third temperature, enabling the thermodynamically unstable impurities to be activated so that they can be easily decomposed in S53, such as using a relatively low heating temperature or heating duration; and not decomposing prematurely in the adsorption step, thus avoiding the pores of the adsorbent being blocked by antimony generated from the premature decomposition of stibine, reducing the adsorption effect of the adsorbent, or reducing the regeneration efficiency of the adsorbent.

[0157] S53: Then heat the second-purity arsine at the third temperature to purify the gas, obtaining an electronic-grade gaseous arsenide. In the step of heating the second-purity arsine at the third temperature to purify the gas, the third temperature is 100 °C to 200 °C.

[0158] In some embodiments, in the step of heating the second-purity arsine at the third temperature to purify the gas, stibine impurities are mainly removed. Among them, the gaseous arsenide is rectified to remove low-boiling-point impurities and most high-boiling-point impurities, and then passed through the adsorbent at the second temperature to remove hydrogen sulfide and synchronously activate other thermodynamically unstable impurities. Therefore, only a small amount of thermodynamically unstable impurities are contained in the second-purity arsine. Therefore, by regulating the third temperature to purify the gas, an electronic-grade gaseous arsenide is obtained.

[0159] Too high a third temperature will cause the pyrolysis of arsine, while too low a temperature cannot effectively remove stibine impurities. Therefore, regulating the third temperature to 100 °C to 200 °C can achieve the removal of stibine impurities through pyrolysis.

[0160] In some specific embodiments, in the step of purifying the gas by heating the second-purity arsine at a third temperature, the third temperature is 120 °C to 180 °C.

[0161] Overall, the gas after purifying the gas by heating the second-purity arsine at a third temperature is an electronic-grade gaseous arsenide. Among them, the specific separation principle of stibine and electronic-grade gaseous arsenide in the second-purity arsine is as follows:

[0162] According to DFT theoretical calculations, for the electronic-grade gaseous arsenide, the dissociation energy of the arsenic-hydrogen bond in the main component arsine (AsH3) is 80.3 kcal / mol, and the dissociation energy of the antimony-hydrogen bond in stibine (SbH3) is 67.7 kcal / mol.

[0163] Convert the bond dissociation energy from kcal / mol to J / mol (calculated by the pyrolysis formula under the International System of Units):

[0164] 1 kcal / mol = 4184 J / mol.

[0165] That is, the bond dissociation energy of arsine: ΔH(AsH3) = 80.3 kcal / mol × 4184 = 336779.2 J / mol.

[0166] The bond dissociation energy of stibine: ΔH(SbH3) = 67.7 kcal / mol × 4184 = 283236.8 J / mol.

[0167] The pyrolysis temperature T can be approximately estimated by the formula: T = ΔH / ΔS.

[0168] Among them, ΔH is: the enthalpy change of the reaction, corresponding to the bond dissociation energy, usually in kcal / mol. ΔS is: the entropy increase of the molecules during the decomposition process, which is calculated as 20 cal / (mol·K) here.

[0169] Through thermodynamic formula calculations, it can be deduced that the theoretical temperature at which bond breakage occurs in arsine is 4024 K, and the theoretical temperature at which bond breakage occurs in stibine is 3384 K. Among them, the temperature required for the antimony-hydrogen bond to break in stibine is lower.

[0170] It should be noted that since the theoretical calculation value ignores the influence of factors such as catalysts and decomposition pressure, the temperature required for bond breakage in the theoretical calculation is on the high side. In the actual pyrolysis temperature, it may be as low as half of the theoretical temperature or even lower. The third temperature involved in this application is the actual temperature determined through relevant experiments.

[0171] Although the temperature required for bond breakage in the theoretical calculation is much higher than the experimental pyrolysis temperature, it still shows that the antimony-hydrogen bond is more easily decomposed than the arsenic-hydrogen bond at a relatively lower temperature.

[0172] According to molecular dynamics simulation calculations, at 200K, the bond length of arsine is 1.59 Å; the bond length of stibine is 1.80 Å. At 700K, the bond length of arsine is 1.70 Å; the bond length of stibine is 1.95 Å. Molecular dynamics simulation calculations also show that the bond length of stibine is longer than that of arsine, and it is relatively easy to decompose.

[0173] Therefore, by adjusting the third temperature, the decomposition and removal of stibine are mainly controlled to obtain an electronic-grade gaseous arsenide product.

[0174] In the above purification method of gaseous arsenide, the gaseous arsenide is placed under the conditions of the first temperature and the first pressure. Utilizing the different boiling points, the distilled gaseous substances are collected, which is arsine of the first purity; the arsine of the first purity is passed into an adsorbent at the second temperature. In addition to removing hydrogen sulfide, hydrogen, and moisture, other thermodynamically unstable impurities are also activated simultaneously to obtain arsine of the second purity; then the arsine of the second purity is heated at the third temperature for purifying the gas, which is the electronic-grade gaseous arsenide. Among them, when the arsine of the second purity is heated at the third temperature, the Sb-H bond in stibine is broken, realizing the pyrolysis and removal of stibine impurities. In some embodiments, through the above impurity removal method, the impurity content in the gaseous arsenide can be effectively reduced to the lowest level, and an ultra-high purity electronic-grade gaseous arsenide with deep purification can be obtained.

[0175] The above purification method of gaseous arsenide prepares an electronic-grade gaseous arsenide product with a purity meeting the electronic-grade standard, meeting the industrial production requirements of high-quality high-purity arsenic products. At the same time, the process flow adopted by the present invention is not only simple to operate and easy to realize industrial production, but also can reduce production costs, and is an efficient and economical purification method of gaseous arsenide.

[0176] The rectification step can be carried out by the rectification mechanism of a single rectification tower for rectification separation, or by a combination of multiple rectification towers for distillation separation. Exemplarily, the rectification mechanism includes a light component removal tower and a heavy component removal tower; the light component removal tower and the heavy component removal tower are connected in series. Among them, the rectification mechanism mainly separates through the boiling point differences between different components, and low-boiling (light) impurities and high-boiling (heavy) impurities are mainly separated through the top and bottom of the two towers.

[0177] Therefore, correspondingly, in some embodiments, the step of rectifying the gaseous arsenide under the conditions of the first temperature and the first pressure includes:

[0178] Rectifying the gaseous arsenide in the light component removal tower under the conditions of the first temperature and the first pressure. Among them, in the light component removal tower, the bottom temperature is 20 - 60 °C higher than the top temperature.

[0179] In this step, the light-end tower is mainly used to remove lighter impurities (such as low-boiling impurities like methane, ethane, silane, etc.). Since the temperature at the top of the tower is relatively low, it can promote the easier volatilization and separation of light components.

[0180] Place the bottom product after rectification in the light-end tower under the conditions of the first temperature and the first pressure for rectification in the heavy-end tower, and collect the substances at the top of the tower to obtain arsine with the first purity. Among them, inside the heavy-end tower, the temperature at the bottom of the tower is 20 - 60 °C higher than the temperature at the top of the tower; the temperature at the top of the light-end tower, the temperature at the bottom of the light-end tower, the temperature at the top of the heavy-end tower, and the temperature at the bottom of the heavy-end tower are all within the first temperature range, and the temperature at the top of the heavy-end tower is 5 - 30 °C higher than the temperature at the top of the light-end tower.

[0181] In this step, the heavy-end tower is mainly used to remove high-boiling impurities (such as water, stibane, or other high-boiling substances). The temperature at the bottom of the tower is higher than the temperature at the top of the tower, which promotes the liquid deposition and reflux separation of heavy components.

[0182] In some embodiments, the temperature at the top of the light-end tower is -80 ~ -60 °C, and the temperature at the bottom of the tower is -40 ~ -20 °C; the first pressure is 0.1 MPa ~ 0.6 MPa.

[0183] The temperature at the top of the heavy-end tower is -70 ~ -50 °C, and the temperature at the bottom of the tower is -30 ~ -10 °C; the first pressure is 0.1 MPa ~ 0.6 MPa.

[0184] In some embodiments, the gaseous arsenide is prepared by uniformly mixing a metal arsenide and a sulfuric acid solution under the conditions of a temperature of 20 ~ 40 °C and a vacuum pressure of 1 ~ 100 Pa.

[0185] Among them, the metal arsenide is one of zinc arsenide, magnesium arsenide, and aluminum arsenide.

[0186] The mass concentration of the sulfuric acid solution is 5 ~ 20%, and the mass ratio of the metal arsenide to the sulfuric acid solution is (5 ~ 15) : 100.

[0187] In some embodiments, the arsine with the first purity contains arsine and impurities; among them, the impurities contain at least one of stibane, silane, phosphine, hydrogen sulfide, and germanane.

[0188] In some embodiments, the arsine with the second purity contains arsine and thermodynamically unstable substances; the thermodynamically unstable substances contain at least one of oxygen, carbon dioxide, nitrogen, germanane, and stibane.

[0189] This application also provides a purification device for gaseous arsenide, including:

[0190] The rectification mechanism is used to rectify gaseous arsenide under the conditions of the first temperature and the first pressure, collect the gaseous substance, and obtain arsine with the first purity; the first temperature is -80°C to -10°C; the first pressure is 0.1 MPa to 0.6 MPa.

[0191] See Figure 9 , Figure 9 is a schematic diagram of the rectification mechanism of this application. Among them, the rectification mechanism includes the top A of the light removal tower; the tower body (packing section) B of the light removal tower; the bottom C of the light removal tower; the top D of the heavy removal tower; the tower body (packing section) E of the heavy removal tower; the bottom F of the heavy removal tower; label 1 is the inlet of gaseous arsenide; label 2 is the outlet of low-boiling impurities; label 3 is the path for the liquid substance to enter the heavy removal tower from the bottom of the light removal tower; label 4 is the outlet of arsine with the first purity; label 5 is the outlet of high-boiling impurities.

[0192] In some embodiments, the gaseous arsenide is placed in the rectification mechanism, and the light component gaseous substance is separated by the light removal tower to obtain a liquid substance; then the heavy component liquid substance is separated by the heavy removal tower to obtain the arsine with the first purity.

[0193] In some embodiments, the rectification mechanism is a low-pressure condensation rectification device that can adjust the temperature and pressure.

[0194] In some embodiments, the gaseous arsenide is prepared by a reaction kettle, and the reaction kettle is directly connected to the rectification mechanism. For example, there is no need to set a condenser between the two. The adsorption mechanism has an adsorbent inside, and the adsorption mechanism is connected to the rectification mechanism. The adsorption mechanism is used to pass the arsine with the first purity through the adsorbent at the second temperature to remove gas impurities and dry it, obtaining arsine with the second purity.

[0195] In some embodiments, the adsorption mechanism can be selected as a straight tower filled with an adsorbent. The arsine with the first purity passes through the straight tower, and the adsorbent can remove hydrogen sulfide and dry the gas, obtaining arsine with the second purity.

[0196] The heating mechanism is connected to the adsorption mechanism. The heating mechanism is used to pass the arsine with the second purity through it for heating at the third temperature to obtain a purified gas; the third temperature is 100 °C to 200 °C.

[0197] In some embodiments, the heating mechanism uses a heating kettle to achieve the removal of thermodynamically unstable impurities in arsine, such as oxygen, carbon dioxide, nitrogen, germane or stibine remaining after the rectification mechanism and adsorption mechanism steps, in a closed atmosphere. Arsine exists in a gaseous state and is collected to achieve the purpose of separation and impurity removal. At the same time, the control of the third temperature of the heating mechanism also avoids the pyrolysis of arsine, further improving the purity and content of arsine.

[0198] In some embodiments, the above purification device for gaseous arsenide further includes:

[0199] The first purifier includes a first gaseous recycler, a first liquid recycler, a second liquid recycler, and a first collector.

[0200] The first gaseous recycler is communicated with the top of the light component removal tower; the first liquid recycler is communicated with the bottom of the light component removal tower; the second liquid recycler is communicated with the bottom of the heavy component removal tower, and the first collector is communicated with the top of the heavy component removal tower and the adsorption mechanism respectively.

[0201] In some embodiments, the first gaseous recycler is used to collect the light component gaseous substances; the first liquid recycler is used to collect the liquid substances; the second liquid recycler is used to collect the heavy component liquid substances; the first collector is used to collect the first purity arsine gas.

[0202] The second purifier includes a second collector; the second collector is communicated with the adsorption mechanism and the heating mechanism respectively.

[0203] In some embodiments, the second purity arsine is collected by the second collector.

[0204] The third purifier includes a second gaseous recycler and a third collector.

[0205] The second gaseous recycler is communicated with the bottom outlet of the heating mechanism and is used to collect the product antimony or arsenic-antimony mixture from the pyrolysis of stibine; the third collector is communicated with the gas phase outlet of the heating mechanism and is used to collect the electronic grade gaseous arsenide.

[0206] In some embodiments, each device in the first purifier, the second purifier, and the third purifier is connected by pipelines; the interfaces between the pipelines are connected in a sealed manner.

[0207] Exemplarily, each device is connected by pipelines for the arsine and impurities to flow through the pipelines, facilitating the removal of impurities.

[0208] Exemplarily again, the interfaces between the pipelines are connected in a sealed manner to ensure that the arsine gas is not lost and no foreign impurities are introduced.

[0209] The sixth part introduces the S6 step in detail.

[0210] S6, pyrolyze and condense the electronic grade gaseous arsenide to obtain high-purity arsenic.

[0211] In some embodiments, it includes the following steps:

[0212] The gaseous arsenide is catalytically cracked and then condensed and collected. The condensate formed is high-purity arsenic. The temperature of the catalytic cracking is 100 °C to 300 °C; the gaseous arsenide is arsine gas.

[0213] After the gaseous arsenide undergoes catalytic cracking, arsine thermally decomposes into gaseous high-purity arsenic. Through condensation, the gaseous high-purity arsenic is converted into solid high-purity arsenic and separated from other gaseous substances (such as unreacted gaseous arsenide, hydrogen generated by catalytic cracking, and trace impurities that may exist in the gaseous arsenide). Among them, the total impurity content of the high-purity arsenic is <0.1 ppm.

[0214] In some embodiments, after the gaseous arsenide undergoes catalytic cracking and condensation, it can be used to remove impurities such as hydrogen.

[0215] Due to its special electronic structure and surface activity, the catalyst can effectively promote the cracking of arsine. These catalysts form coordination bonds with arsine to lower the energy barrier of the reaction, increase the reaction rate, thereby obtaining high-purity arsenic, effectively reducing the reaction temperature, and increasing the rate of arsine pyrolysis.

[0216] In some embodiments, the catalyst is one of the oxides corresponding to transition metals / noble metals.

[0217] In some embodiments, the transition metals include cobalt, nickel, copper, or manganese; the noble metals include gold, silver, or platinum.

[0218] In some specific embodiments, the catalyst is selected from copper oxide, silver oxide, or nickel oxide. In particular, the preferred catalyst is copper oxide, which shows good performance in the process of catalytic cracking of arsine to high-purity arsenic, mainly due to its unique ability to regulate electronic states. The surface of copper oxide contains Cu 2+ and Cu + two different chemical electronic states. Cu 2+ can participate in the reaction as an oxidation source to promote the dehydrogenation reaction of arsine to generate high-purity arsenic; while Cu + as reduced copper helps to promote the release of elemental arsenic and reduce the generation of by-products. Similarly, silver oxide and nickel oxide surfaces have similar electron transfer capabilities, which can promote the adsorption and dehydrogenation of arsine, and finally catalytically crack arsine into elemental arsenic. In summary, the dynamic regulation of electrons on the surface of these metal catalysts makes the reaction have good selectivity and high efficiency, thus significantly increasing the yield of arsine converted to high-purity arsenic and ensuring that the final product is high-purity arsenic.

[0219] In some embodiments, the catalytic cracking of arsine is achieved by adding an external catalyst, which can significantly reduce the activation energy and reaction temperature of the cracking reaction, thereby accelerating the decomposition of macromolecular compounds such as arsine gas into gaseous arsenic and hydrogen, promoting the decomposition of arsine at a lower temperature, and thus preparing high-purity arsenic.

[0220] In addition, the introduction of the catalyst avoids the problem of impurity residues commonly found in high-temperature pyrolysis, thus effectively improving the purity and yield of high-purity arsenic. It should be noted that both pyrolysis and catalytic pyrolysis refer to the destruction of the gaseous molecular bonds of arsine, the pyrolysis of arsine into gaseous high-purity arsenic, and then the condensation of the gaseous high-purity arsenic into solid high-purity arsenic by a condenser.

[0221] In some embodiments, the temperature of catalytic pyrolysis is 120 °C to 250 °C; the duration of catalytic pyrolysis is 1 to 2 h.

[0222] In some embodiments, the temperature of condensation is 50 to 150 °C lower than the temperature of the catalytic pyrolysis; the duration of condensation is 1 to 2 h.

[0223] In some specific embodiments, the temperature of the catalytic pyrolysis is 200 °C, the temperature of condensation is 100 °C, and the duration of both the catalytic pyrolysis and the condensation is 1 h. Among them, the heating duration needs to be controlled. If the heating duration is too short, the impurities will not be completely removed; if the heating duration is too long, the preparation efficiency of high-purity arsenic will be affected.

[0224] In some embodiments, the gaseous arsenide gas is catalytically pyrolyzed under a slightly positive pressure condition, and the pressure of the slightly positive pressure is 0.001 to 0.02 MPa. By catalytically pyrolyzing arsine to prepare high-purity arsenic under a slightly positive pressure condition, the continuous progress of the catalytic conversion process can be effectively maintained, and the arsine gas can be prevented from rapidly escaping to the condensation outlet due to excessive pressure.

[0225] In some embodiments, in the step of catalytically pyrolyzing the gaseous arsenide, the arsine flows in the form of an air flow bundle and is heated along the flow path.

[0226] In some embodiments, in the steps of catalytic pyrolysis and condensation, there are pipelines with different pipe diameters and pipe lengths, which can directionally guide the flow of arsine gas and control the pyrolysis rate. Arsine flows in the corresponding pipeline, that is, it flows along the corresponding flow path in the form of an air flow bundle.

[0227] In some embodiments, the pipe diameter is 2 to 6 cm and the pipe length is 8 to 12 cm. With the mutual cooperation of the pipe diameter and the pipe length, the control of the gaseous molecular air flow is realized, and the pyrolysis of arsine into gaseous high-purity arsenic is realized.

[0228] In some embodiments, the flow rate of the arsine flowing in the form of an air flow bundle is 1 to 2 L / min / cm 2 。

[0229] In some embodiments, the addition amount of the catalyst is 0.005% to 0.01% g / L of the arsine gas flow rate.

[0230] In some embodiments, the amount of catalyst added is 5% to 10% of the mass of the gaseous arsenide. When the gaseous arsenide is added in the form of an air flow beam, correspondingly, the amount of the gaseous arsenide added remains unchanged, and the catalyst is added in the manner of 0.005% to 0.01% g / L of the arsine gas flow rate. For example, when the arsine gas flow rate is 1 L, the corresponding amount of catalyst added is 0.005% to 0.01% g.

[0231] In some embodiments, the high-purity arsenic is encapsulated in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0232] In some embodiments, the enclosure is achieved through a sealed interface. The sealed interface methods include a face seal (VCR) joint connected to a ball valve, a VCR connected to a VCR, and a VCR connected to a ferrule; among them, the sealed interface method is not specifically limited, as long as the connection tightness and reliability can be ensured.

[0233] In some embodiments, in a closed protective gas environment, the high-purity arsenic is transferred to a glove box and encapsulated with an electronic-grade packaging bag to ensure that the high-purity arsenic is not contaminated by oxygen and moisture in the outside air during the transfer and encapsulation processes, thereby further reducing the impurity content and ensuring the stability of the product quality.

[0234] For the above method for catalytic cracking of gaseous arsenide, after the gaseous arsenide is catalytically cracked and then condensed and collected, the condensate formed is high-purity arsenic; the temperature of the catalytic cracking is 100 °C to 300 °C; the gaseous arsenide is arsine gas; the total impurity content of the high-purity arsenic is <0.1 ppm. By adopting the method of strictly controlling the temperature of the catalytic cracking and utilizing the catalytic action of the catalyst, the gaseous arsenide is catalytically cracked into gaseous high-purity arsenic at a low temperature, and after condensation, it is converted into solid high-purity arsenic and collected. Moreover, the method for catalytic cracking of gaseous arsenide provided by the present invention has a simple process, convenient operation, and high purity and yield of the prepared high-purity arsenic product.

[0235] The present invention also provides a device for catalytic cracking of gaseous arsenide, comprising:

[0236] A catalytic cracking device, comprising a heater with adjustable temperature, a condenser and a collector.

[0237] The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein, the temperature of the catalytic cracking is 100 °C to 300 °C; the duration of the catalytic cracking is 1 to 2 h.

[0238] In some embodiments, the temperature of the catalytic cracking is 200 °C and the duration of the catalytic cracking is 1 h.

[0239] In some embodiments, the heater can be a pyrolysis tower, which only needs to be able to achieve temperature control within a certain range and can return to room temperature after heating stops. The heating temperature control range of the heater is 100 °C to 300 °C. It is used to catalytically pyrolyze arsine.

[0240] In some embodiments, the gaseous arsenide is introduced into the catalytic cracking device. First, it is heated by the heater, where a catalyst is placed. By adjusting the temperature, the arsenic-hydrogen bond is broken due to pyrolysis, realizing the pyrolysis of arsine into gaseous high-purity arsenic, and then it is condensed into solid high-purity arsenic by the condenser.

[0241] The condenser is connected to the heater and is used to condense the pyrolyzate of arsine in the pyrolysis gas to form condensate; the condensation time is 1 to 2 hours.

[0242] The collector is connected to the condensation outlet of the condenser and is used to collect the condensate to obtain the high-purity arsenic.

[0243] The recycler is connected to the gas-phase outlet of the condenser and is used to collect the gas-phase substances.

[0244] In some embodiments, hydrogen, oxygen and other impurities are collected in the recycler.

[0245] In some embodiments, the collector is used to collect the condensate as solid high-purity arsenic.

[0246] In some embodiments, the heater is hermetically connected to the condenser and the collector in sequence.

[0247] Among them, the collector is located below the condenser.

[0248] In some embodiments, on the same horizontal plane, from left to right, the heater is hermetically connected to the condenser and the collector in sequence. Among them, the collector is located below the condenser.

[0249] In some embodiments, the heater is connected to the condenser, the collector and the recycler in sequence.

[0250] Among them, the condenser is connected to the heater.

[0251] The collector is located below the condenser.

[0252] In some embodiments, on the same horizontal plane, from left to right, the heater is connected to the condenser, the collector and the recycler. Among them, the connection method is hermetic connection.

[0253] In some embodiments, the condenser is connected to the heater; the collector is located below the condenser; the recycler is located above the condenser, and the position of the recycler is not specifically limited, as long as it can achieve the purpose of recycling gas.

[0254] In some embodiments, in the heater, during the process of pyrolyzing arsine and condensing to obtain solid high-purity arsenic, the total impurity content of the high-purity arsenic is <0.1 ppm; high-purity arsenic products with a purity of 7N or higher grade are obtained.

[0255] The preparation device for catalytic cracking of gaseous arsenide into high-purity arsenic provided by this application has a simple process, convenient operation, simplifies the preparation process, reduces the production difficulty, realizes the pyrolysis of arsine and the removal of impurities, and obtains high-purity arsenic products with a purity of 7N or higher grade.

[0256] The pressure in the pyrolysis device corresponding to this part in the examples and comparative examples is 0.01 MPa. The yield is the actual yield, and the yield = (mass of high-purity arsenic / mass of arsine) × 100%.

[0257] For a further understanding of the present invention, examples are given below for illustration:

[0258] Among them, Example 1 and Example 2 correspond to the technical solution description of step S1.

[0259] Example 1

[0260] 1. Microwave-dry the arsenic sulfide slag (As2S3) with a moisture content of 60%. After drying for 1 h, put it into a crusher and crush it into 200-mesh powder. Weigh a certain amount of iron powder and arsenic sulfide slag powder as raw materials using an electronic balance, and add them to a two-temperature zone roasting furnace according to a molar ratio of iron element to arsenic element of 3:1.

[0261] 2. Set the two-temperature zone temperature and then carry out the roasting and purification reaction; among them, the roasting temperature: the reaction zone is 650 °C, the material receiving zone is 450 °C, and after keeping warm for 4 h, both are naturally cooled to room temperature.

[0262] 3. Obtain the first-purity crude arsenic by collecting in the material receiving zone, and perform ICP analysis. Its main impurity is Sb, with a content of 1326 mg / g, and finally the purity of the first-purity crude arsenic is 2N.

[0263] Specifically, the elemental quantitative analysis results of the first-purity crude arsenic are as Figure 1 shown, according to Figure 1Analysis shows that the Sb content reaches 1326.2 ppm, which is the impurity element with the highest content. Other impurity elements include Si, S, B, etc., and their concentrations are 52.3 ppm, 4.6 ppm, 1.5 ppm respectively. In addition, the oxygen element content is relatively high, reaching 7.4%. The purity of the first-purity crude arsenic sample is analyzed, and it is oxygen-containing crude arsenic of 2N grade. The purity of the first-purity crude arsenic is obtained by measuring the impurity content through ICP full-element determination, excluding the oxygen content. The oxygen content is listed separately through an oxygen content analyzer.

[0264] Full scan of the elemental content of the first-purity crude arsenic is as Figure 2 shown. The elemental content of the first-purity crude arsenic is fully scanned, and the purity analysis is carried out by the difference method. According to Figure 2 the results of elemental quantitative analysis, Sb is the main impurity in the first-purity crude arsenic, and the impurity content is as high as 0.18%. Other important impurities include Ca, Fe, K, Na, Se, etc., which are 0.0019%, 0.0053%, 0.0010%, 0.0038%, 0.0037% respectively.

[0265] The XRD phase analysis diagram of the first-purity crude arsenic is as Figure 3 shown. According to Figure 3 observation, the mineral composition of the first-purity crude arsenic mainly contains a large amount of arsenic oxide in addition to elemental arsenic.

[0266] Example 2

[0267] Compared with Example 1, only the roasting temperatures in the reaction zone and the material collection zone in Step 2 are changed:

[0268] 1. The arsenic sulfide slag (As2S3) with a moisture content of 60% is dried by microwave for 1 h and then put into a crusher to be crushed into 200-mesh powder. A certain amount of iron powder and arsenic sulfide slag powder are weighed by an electronic balance as raw materials and added into a double-temperature zone roasting furnace according to a molar ratio of iron element to arsenic element of 3:1.

[0269] 2. After setting the double-temperature zone temperatures, the roasting and purification reaction is carried out. Among them, the roasting temperature in the reaction zone is 700 °C and in the material collection zone is 500 °C. After keeping warm for 4 h, it is naturally cooled to room temperature.

[0270] 3. The first-purity crude arsenic is obtained by collecting in the material collection zone, and its main impurity analyzed by ICP is Sb, with a content of 1791 mg / g. Finally, the purity of the first-purity crude arsenic obtained is 2N.

[0271] Example 3

[0272] 1. First, 100 g of the first-purity crude arsenic prepared in Example 1, 5 g of carbon powder, and 10 g of copper powder are placed in an inert atmosphere, and the mixed arsenic material is fully mixed by a mixer and then added into a vacuum container.

[0273] 2. Evacuate the vacuum container until the vacuum degree reaches 0.001 Pa, then seal it. Place the sealed vacuum container in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature is 700 °C, the cold end temperature is 500 °C, and the sublimation time is 6 h. After the sublimation reaction is completed, cool it to obtain purified arsenic bulk.

[0274] 3. Take out the purified arsenic bulk under an inert atmosphere, crush it through a grinding machine and then screen it. Set the crusher time to 10 minutes and the mesh number of the sieve to 200 mesh. Finally, obtain arsenic single - element powder products that meet the requirements, namely the second - purity crude arsenic.

[0275] The purity of the second - purity crude arsenic is 99.95%, the antimony content is 286.5 mg / kg, and the oxygen content is 0.31%.

[0276] Example 4

[0277] Compared with Example 3, only change the dosage of the first reducing agent in step 1:

[0278] 1. First, place 100 g of the first - purity crude arsenic prepared in Example 1, 3 g of carbon powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0279] 2. Evacuate the vacuum container until the vacuum degree reaches 0.001 Pa, then seal it. Place the sealed vacuum container in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature is 700 °C, the cold end temperature is 500 °C, and the sublimation time is 6 h. After the sublimation reaction is completed, cool it to obtain purified arsenic bulk.

[0280] 3. Take out the purified arsenic bulk under an inert atmosphere, crush it through a grinding machine and then screen it. Set the crusher time to 10 minutes and the mesh number of the sieve to 200 mesh. Finally, obtain arsenic single - element powder products that meet the requirements, namely the second - purity crude arsenic.

[0281] The purity of the second - purity crude arsenic is 99.95%, the antimony content is 265.2 mg / kg, and the oxygen content is 0.38%.

[0282] Example 5

[0283] Compared with Example 3, only change the dosage of the first reducing agent in step 1:

[0284] 1. First, place 100 g of the first - purity crude arsenic prepared in Example 1, 1 g of carbon powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0285] 2. Evacuate the vacuum container until the vacuum degree reaches 0.001 Pa, then seal it. Place the sealed vacuum container in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature is 700 °C, the cold end temperature is 500 °C, and the sublimation time is 6 h. After the sublimation reaction ends, cool it to obtain purified arsenic bulk.

[0286] 3. Take out the purified arsenic bulk under an inert atmosphere, crush it through a grinding machine and then screen it. Set the crusher time to 10 minutes and the mesh number of the sieve to 200 meshes, and finally obtain arsenic elemental powder products that meet the requirements, namely the second-purity crude arsenic.

[0287] The purity of the second-purity crude arsenic is 99.95%, the antimony content is 234.3 mg / kg, and the oxygen content is 0.47%.

[0288] Example 6

[0289] Compared with Example 3, only change the temperatures of the hot and cold ends in Step 2:

[0290] 1. First, place 100 g of the first-purity crude arsenic prepared in Example 1, 5 g of carbon powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Add the mixed arsenic material to a vacuum container.

[0291] 2. Evacuate the vacuum container until the vacuum degree reaches 0.001 Pa, then seal it. Place the sealed vacuum container in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature is 650 °C, the cold end temperature is 450 °C, and the sublimation time is 6 h. After the sublimation reaction ends, cool it to obtain purified arsenic bulk.

[0292] 3. Take out the purified arsenic bulk under an inert atmosphere, crush it through a grinding machine and then screen it. Set the crusher time to 10 minutes and the mesh number of the sieve to 200 meshes, and finally obtain arsenic elemental powder products that meet the requirements, namely the second-purity crude arsenic.

[0293] The purity of the second-purity crude arsenic is 99.99%, the antimony content is 180.7 mg / kg, and the oxygen content is 0.36%. Conduct a full-element determination on the prepared second-purity crude arsenic powder, and the results are as Figure 4 shown. It is found that after vacuum sublimation, the antimony content is reduced by more than 89% significantly, and the purity of the volatilized crude arsenic is increased from 2N to 4N. By vacuum sublimation in the first vacuum environment in cooperation with the first reducing agent and purifying agent, low-volatility impurities such as antimony are volatilized from the crude arsenic, further improving the purity of arsenic.

[0294] Example 7

[0295] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, and add activated carbon powder with a mass of 0.1% of the mass of the second-purity crude arsenic. Mix thoroughly through a mixer, and add the arsenic metal mixture into a vacuum container.

[0296] 2. Evacuate the vacuum container containing the arsenic metal mixture. After the vacuum degree is pumped to 0.001 Pa, seal it, and place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 800 °C and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0297] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration. The product phase analysis diagram of the metal arsenide prepared in this example is as Figure 5 shown in (a). The crystal structure completely conforms to the standard Zn3As2 card configuration, and no oxidized impurities are detected (that is, by comparing the measured XRD peaks with the standard PDF card, comparing the positions and heights of the main peaks, secondary main peaks, etc.).

[0298] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.09; Zn 67.02; As 31.89. Due to the difference between the saturated vapor pressure and the maximum evaporation rate between arsenic and antimony under vacuum conditions, no antimony is detected in the product; by adding a trace amount of reducing agent in the second vacuum environment, the impurities and oxygen content of the finally prepared metal arsenide are effectively controlled.

[0299] Example 8

[0300] Compared with Example 7, only change the melting reaction temperature in Step 2:

[0301] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, and add activated carbon powder with a mass of 0.1% of the mass of the second-purity crude arsenic. Mix thoroughly through a mixer, and add the arsenic metal mixture into a vacuum container.

[0302] 2. Evacuate the vacuum container with the arsenic metal mixture. After the vacuum degree is pumped to 0.001 Pa, seal it, and place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 780 °C and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0303] 3. Take out the metal arsenide block under an inert atmosphere, crush it through a ball mill and then sieve it. Set the ball milling time to 6 hours and the sieve mesh to 6 meshes. Finally, the metal arsenide particle product that meets the requirements is obtained. The product purity reaches 99.9% and the crystal structure conforms to the standard Zn3As2 card configuration.

[0304] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 0.74; Zn 66.28; As 32.93; Sb 0.05.

[0305] Example 9

[0306] Compared with Example 7, only the melting temperature in the step is changed:

[0307] 1. First, place 100 g of the second purity crude arsenic obtained in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the second purity crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0308] 2. Evacuate the vacuum container containing the mixed material, and seal it after the vacuum degree is reduced to 0.001Pa. Place the sealed vacuum container in a high-temperature furnace for melting reaction. Set the reaction temperature to 900°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0309] 3. Take out the metal arsenide block under an inert atmosphere, crush it with a ball mill and then sieve it. Set the ball milling time to 6 hours and the mesh size to 6 meshes to finally obtain a metal arsenide particle product that meets the requirements, and the product purity reaches 99%. The phase analysis diagram of the metal arsenide product prepared in this embodiment is as follows: Figure 5 As shown in (c), the crystal structure conforms to the standard Zn3As2 card configuration and contains a small amount of ZnO structure.

[0310] In terms of mass fraction, the chemical composition of metal arsenide includes (wt%): O 1.16; Zn 65.39; As 33.12; Sb 0.32.

[0311] Example 10

[0312] Compared with Example 7, only the melting temperature in the step is changed:

[0313] 1. First, place 100 g of the second purity crude arsenic obtained in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the second purity crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0314] 2. Evacuate the vacuum container containing the mixed material, and seal it after the vacuum degree is drawn to 0.001Pa. Place the sealed vacuum container in a high-temperature furnace for melting reaction. Set the reaction temperature to 1000°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0315] 3. Take out the metal arsenide block under an inert atmosphere, crush it with a ball mill and then sieve it. Set the ball milling time to 6 hours and the mesh size to 6. Finally, obtain the metal arsenide particle product that meets the requirements. The product purity reaches 99% and the crystal structure conforms to the standard Zn3As2 card configuration (that is, compare the measured XRD peak with the standard PDF card to compare the main peak, secondary main peak and other positions highly overlapped).

[0316] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 2.15; Zn 66.03; As 31.60; Sb 0.22.

[0317] Embodiment 11

[0318] Compared with Example 7, only the ratio of the arsenic active metal material in step 1 is changed:

[0319] 1. First, place 100 g of the second purity crude arsenic obtained in Example 3 and 150 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the second purity crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0320] 2. Evacuate the vacuum container containing the mixed material, and seal it after the vacuum degree is reduced to 0.001Pa. Place the sealed vacuum container in a high-temperature furnace for melting reaction. Set the reaction temperature to 800°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0321] 3. Take out the metal arsenide block under an inert atmosphere, crush it with a ball mill and then sieve it. Set the ball milling time to 6 hours and the sieve mesh to 6 meshes. Finally, the metal arsenide particle product that meets the requirements is obtained. The product purity reaches 99%, the crystal structure conforms to the standard Zn3As2 card configuration, and only contains a small amount of elemental zinc.

[0322] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.03; Zn 73.21; As 25.49; Sb 0.27.

[0323] Example 12

[0324] Compared with Example 7, only the vacuum conditions in step 2 were changed:

[0325] 1. First, place 100 g of the second-purity crude arsenic obtained in Example 3 and 130 g of zinc powder in an inert atmosphere, and add activated carbon powder with a mass of 0.1% of the mass of the second-purity crude arsenic. Mix thoroughly through a mixer, and add the mixture to a vacuum container.

[0326] 2. Evacuate the vacuum container with the mixture. After the vacuum degree reaches 1 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 800 °C and the reaction time at 6 h. After the melting reaction ends, cool it to obtain a metal arsenide block. The product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0327] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 mesh. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0328] By mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.21; Zn 68.27; As 30.19; Sb 0.33.

[0329] Example 13

[0330] Compared with Example 7, only change the type of active metal material in Step 1:

[0331] 1. First, place 100 g of the second-purity crude arsenic obtained in Example 3 and 130 g of magnesium powder in an inert atmosphere, and add activated carbon powder with a mass of 0.1% of the mass of the second-purity crude arsenic. Mix thoroughly through a mixer, and add the mixture to a vacuum container.

[0332] 2. Evacuate the vacuum container with the mixture. After the vacuum degree reaches 0.001 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 800 °C and the reaction time at 6 h. After the melting reaction ends, cool it to obtain a metal arsenide block. The product purity reaches 99.9%, and the crystal structure conforms to the standard Mg3As2 card configuration.

[0333] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 mesh. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%.

[0334] By mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.91; Mg 62.90; As 35.00; Sb 0.19.

[0335] Embodiment 14

[0336] Compared with Example 7, only the type of the second reducing agent in step 1 is changed:

[0337] 1. First, place 100 g of the second purity crude arsenic obtained in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% carbon black powder of the mass of the second purity crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0338] 2. Evacuate the vacuum container containing the mixed material, seal it after the vacuum degree is reduced to 0.001Pa, place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature to 800°C, and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block. The product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0339] 3. Take out the metal arsenide block under an inert atmosphere, crush it through a ball mill and then sieve it. Set the ball milling time to 6 hours and the sieve mesh to 6 meshes. Finally, obtain the metal arsenide particle product that meets the requirements, and the product purity reaches 99%.

[0340] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 0.87; Zn 63.82; As 35.06; Sb 0.26.

[0341] Embodiment 15

[0342] 1. First, 500 g of the metal arsenide prepared in Example 7 was placed in a reaction device, and the gas in the reaction device was replaced by vacuuming and supplementing nitrogen. The vacuum degree of the device was reduced to 100 Pa for the last vacuuming, and the temperature of the sulfuric acid in the environment was maintained at 30°C.

[0343] 2. The addition of sulfuric acid is controlled by a liquid inlet device, wherein the addition rate of sulfuric acid is controlled at 50 mL / min, the sulfuric acid is present in the form of a sulfuric acid solution, the mass concentration of the sulfuric acid solution is 10%, and the amount of arsine gas generated is about 1 L / min. During the reaction, arsine gas is continuously generated and enters the rear-end drying and dehydration device, and the reaction time is 60 min. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.3 mol / L.

[0344] 3. The temperature of the drying and dehydration device is set to 80°C, so that the moisture and other impurities in the arsine gas are dried and removed in the drying and dehydration device, thereby obtaining crude arsine gas (i.e., gaseous arsenide) with extremely low moisture content (<0.1%), and the product quality meets the requirements.

[0345] Example 16

[0346] Compared with Example 15, only step 2 is changed; that is, the addition rate of sulfuric acid is changed:

[0347] 1. First, place 500 g of the metal arsenide prepared in Example 7 in the reaction device, perform gas replacement on the reaction device by evacuating and replenishing nitrogen, and finally evacuate to reduce the vacuum degree of the device to 100 Pa, and maintain the temperature of the sulfuric acid in the environment at 30 °C.

[0348] 2. Control the addition of sulfuric acid through the liquid inlet device, where the addition rate of sulfuric acid is controlled at 100 mL / min. The sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 10%. The amount of arsine gas generated is about 2 L / min, and arsine gas is continuously generated during the reaction and enters the backend drying and water removal device. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.25 mol / L.

[0349] 3. Set the temperature of the drying and water removal device to 80 °C. Thus, moisture and other impurities in the arsine gas are dried and removed in the drying and water removal device, and the crude arsine gas (i.e., gaseous arsenide) with a very low moisture content (<0.1%) is obtained, and the product quality meets the requirements.

[0350] Example 17

[0351] Compared with Example 15, only step 1 is changed; that is, the dosage of the metal arsenide is changed:

[0352] 1. First, place 300 g of the metal arsenide prepared in Example 7 in the reaction device, perform gas replacement on the reaction device by evacuating and replenishing nitrogen, and finally evacuate to reduce the vacuum degree of the device to 100 Pa, and maintain the temperature of the sulfuric acid in the environment at 30 °C.

[0353] 2. Control the addition of sulfuric acid through the liquid inlet device, where the addition rate of sulfuric acid is controlled at 50 mL / min. The sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 10%. The amount of arsine gas generated is about 1 L / min, and arsine gas is continuously generated during the reaction and enters the backend drying and water removal device. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.5 mol / L.

[0354] 3. Set the temperature of the drying and water removal device to 80 °C. Thus, moisture and other impurities in the arsine gas are dried and removed in the drying and water removal device, and finally, the crude arsine gas (i.e., gaseous arsenide) with a very low moisture content (<0.1%) is obtained, and the product quality meets the requirements.

[0355] Example 18

[0356] Compared with Example 3, only the type of the first reducing agent in Step 1 is changed:

[0357] 1. First, place 100 g of the first-purity crude arsenic obtained in Example 1, 5 g of zinc powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0358] 2. Evacuate the vacuum container with the mixed material. After the vacuum degree reaches 0.001 Pa, seal it. Then place the sealed vacuum container in a multi-zone vacuum sublimation furnace for sublimation reaction. The hot-end temperature is 700 °C, the cold-end temperature is 500 °C, and the sublimation time is 6 h. After the sublimation reaction ends, cool it to obtain a purified arsenic block.

[0359] 3. Take out the purified arsenic block in an inert atmosphere, crush it through a grinding machine and then screen it. Set the crushing time of the crusher to 10 minutes and the mesh number of the sieve to 200 meshes. Finally, obtain an arsenic single-element powder product that meets the requirements, that is, the second-purity crude arsenic.

[0360] The purity of the second-purity crude arsenic is 99%, and the antimony content is 564.5 mg / kg.

[0361] Comparative Example 1

[0362] Compared with Example 3, only the type of the first reducing agent in Step 1 is changed:

[0363] 1. First, place 100 g of the first-purity crude arsenic obtained in Example 1, 5 g of aluminum powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0364] 2. Evacuate the vacuum container with the mixed material. After the vacuum degree reaches 0.001 Pa, seal it. Then place the sealed vacuum container in a multi-zone vacuum sublimation furnace for sublimation reaction. The hot-end temperature is 700 °C, the cold-end temperature is 500 °C, and the sublimation time is 6 h. After the sublimation reaction ends, cool it to obtain a purified arsenic block.

[0365] 3. Take out the purified arsenic block in an inert atmosphere, crush it through a grinding machine and then screen it. Set the crushing time of the crusher to 10 minutes and the mesh number of the sieve to 200 meshes. Finally, obtain an arsenic single-element powder product that meets the requirements, that is, the second-purity crude arsenic.

[0366] In this comparative example, the purity of the second-purity crude arsenic is 99%, the antimony content is 873.8 mg / kg, and the oxygen content is 1.21%. Due to the poor reduction performance of the first reducing agent, arsenic oxide and antimony oxide with high saturated vapor pressure are continuously generated and escape to the cold end, resulting in a significant increase in the concentration of antimony in the purified arsenic powder.

[0367] Comparative Example 2

[0368] Compared with Example 3, only the temperatures of the hot and cold ends in Step 2 are changed:

[0369] 1. First, place 100 g of the first-purity crude arsenic obtained in Example 1, 5 g of carbon powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0370] 2. Evacuate the vacuum container with the mixed material. After the vacuum degree reaches 0.001 Pa, seal it. Place the sealed vacuum container in a multi-zone vacuum sublimation furnace for sublimation reaction. The temperature of the hot end is 450 °C, the temperature of the cold end is 250 °C, and the sublimation time is 6 h. Since the volatilization temperature is too low, arsenic is not completely volatilized.

[0371] Comparative Example 3

[0372] Compared with Example 3, only the vacuum degree in Step 2 is changed:

[0373] 1. First, place 100 g of the first-purity crude arsenic obtained in Example 1, 5 g of carbon powder, and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0374] 2. Evacuate the vacuum container with the mixed material. After the vacuum degree reaches 100 Pa, seal it. Place the sealed vacuum container in a multi-zone vacuum sublimation furnace for sublimation reaction. The temperature of the hot end is 700 °C, the temperature of the cold end is 500 °C, and the sublimation time is 6 h. Since the vacuum degree is too high, arsenic is not completely volatilized.

[0375] Comparative Example 4

[0376] Compared with Example 3, only a purification agent is added without adding a first reducing agent:

[0377] 1. First, place 100 g of the first-purity crude arsenic obtained in Example 1 and 10 g of copper powder in an inert atmosphere, and fully mix them through a mixer to obtain a mixed arsenic material. Then add the mixed arsenic material into a vacuum container.

[0378] 2. Evacuate the vacuum container. After the vacuum degree reaches 0.001 Pa, seal it. Place the sealed vacuum container in a multi-zone vacuum sublimation furnace for sublimation reaction. The temperature of the hot end is 700 °C, the temperature of the cold end is 500 °C, and the sublimation time is 6 h. After the sublimation reaction is completed, cool it to obtain a purified arsenic bulk.

[0379] In this comparative example, the purity of the purified arsenic powder is 99.3%, the antimony content is 853.52 mg / kg, and the oxygen content is 4.56%. Since no reducing agent is added, it is difficult to reduce the oxidized impurities to the lower-valence arsenic that is more prone to sublimation. Therefore, the purification effect of arsenic is poor, and most of the remaining oxidized arsenic in the crude arsenic is not reduced.

[0380] Comparative Example 5

[0381] Compared with Example 7, only the melting temperature in Step 2 is changed:

[0382] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder by mass of the first-purity crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0383] 2. Evacuate the vacuum container with the mixture. After the vacuum degree is pumped to 0.001 Pa, seal it, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature at 700 °C, and the reaction time at 6 h. After the melting reaction is completed, cool to obtain a metal arsenide block.

[0384] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, due to the relatively low melting temperature, the ratio of arsenic to metal does not conform to the dosage ratio of the metal arsenide, and the crystal structure of the product tends to be the elemental arsenic card configuration. The phase analysis diagram of the metal arsenide product prepared in this comparative example is as Figure 5 shown in (b), and the crystal structure is mainly the elemental As card configuration.

[0385] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 2.00; Zn 3.08; As 94.59; Sb 0.33. At this temperature, arsenic has started to volatilize and densely coat the outer surface of the oxygen-containing crude arsenic, affecting the formation of gaseous arsenic. In addition, the reaction activity of zinc is relatively low, and the reaction between arsenic and zinc is blocked, resulting in an imbalance in the ratio of arsenic to metal in the subsequent metal arsenide and the crystal structure of the product tending to be the elemental arsenic card configuration.

[0386] Comparative Example 6

[0387] Compared with Example 7, only the reaction time and vacuum conditions in Step 2 are changed:

[0388] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder by mass of the second-purity crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0389] 2. Seal the vacuum container with the mixture under normal pressure (i.e., without vacuum pumping), place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature at 800 °C and the reaction time at 2 h. At the end of the melting reaction, due to the too short reaction time, the final product was not completely reacted and presented a two-phase structure of separate elemental arsenic and zinc, so the metal arsenide bulk after the reaction was not obtained.

[0390] Comparative Example 7

[0391] Compared with Example 7, only the reaction time in Step 2 was changed:

[0392] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder by mass of the second-purity crude arsenic, mix well through a mixer, and add the mixture to a vacuum container.

[0393] 2. Vacuum pump the vacuum container with the mixture to 0.001 Pa and then seal it. Place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature at 800 °C and the reaction time at 4 h. At the end of the melting reaction, due to the too short reaction time, an obvious two-phase structure could be seen. Because the reaction time was too short, the final product was not completely reacted and presented a two-phase structure of separate elemental arsenic and zinc, so the metal arsenide bulk after the reaction was not obtained.

[0394] Comparative Example 8

[0395] Compared with Example 7, only the vacuum degree in Step 2 was changed:

[0396] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder by mass of the second-purity crude arsenic, mix well through a mixer, and add the mixture to a vacuum container.

[0397] 2. Vacuum pump the vacuum container with the mixture, seal it after pumping the vacuum degree to 100 Pa. Place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature at 800 °C and the reaction time at 6 h. After the melting reaction ended, cool it to obtain a metal arsenide bulk. Due to the relatively high vacuum degree of the reaction conditions, the Zn3As2 phase in the product was partially oxidized, and arsenic oxide appeared in the product, which had a certain adverse effect on the subsequent gas-producing reaction for preparing high-purity arsenic from the product.

[0398] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain metal arsenide particles. The product purity is 99%, the crystal structure conforms to the standard Zn3As2 card configuration, and the oxygen content is 2.78%.

[0399] Comparative Example 9

[0400] Compared with Example 7, only the vacuum degree in Step 2 is changed:

[0401] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 0.1% of the mass of the second-purity crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0402] 2. Seal the vacuum container with the mixture without evacuating (i.e., at normal pressure), place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature at 800 °C, and the reaction time at 6 h. After the melting reaction is completed, cool to obtain a metal arsenide block. Since no vacuum environment is set, the Zn3As2 phase in the product is largely oxidized, and a large amount of arsenic oxide appears in the product, which has an extremely adverse effect on the subsequent gas production reaction for preparing high-purity arsenic.

[0403] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a metal arsenide / arsenic oxide mixed particle, with the oxygen content of the product being 20.36%, and the product does not meet the requirements.

[0404] Comparative Example 10

[0405] Compared with Example 7, only the ratio of the arsenic active metal materials in Step 1 is changed:

[0406] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 100 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 0.1% of the second-purity crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0407] 2. Evacuate the vacuum container with the mixture, seal it after the vacuum degree is pumped to 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for melting reaction, set the reaction temperature at 800 °C, and the reaction time at 6 h. After the melting reaction is completed, cool to obtain a metal arsenide block. Since the zinc content in the raw materials is insufficient, in addition to Zn3As2, part of ZnAs2 is also contained in the phase structure of the product, which has a certain adverse effect on the subsequent gas production process for preparing high-purity arsenic, and the gas production amount decreases.

[0408] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a mixed particle product of Zn3As2 and ZnAs2.

[0409] Comparative Example 11

[0410] Compared with Example 15, only the vacuum condition in Step 1 is changed:

[0411] 1. First, place 500 g of the metal arsenide prepared in Example 7 in a reaction device. The inside of the reaction device is under normal pressure and in an air atmosphere.

[0412] 2. Control the addition of sulfuric acid through a liquid inlet device. The addition rate of sulfuric acid is controlled at 50 mL / min. The sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 10%. The amount of arsine gas generated is about 1 L / min. Arsine gas is continuously generated during the reaction and enters the backend drying and water removal device. The reaction time is 60 min. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.3 mol / L.

[0413] 3. Set the temperature of the drying and water removal device to 80°C. However, due to the lack of vacuum replacement, the moisture content of the finally obtained crude arsine gas (>1.3%) does not meet the requirements.

[0414] Comparative Example 12

[0415] Compared with Example 15, only Step 2 is changed; that is, the addition rate of sulfuric acid is changed:

[0416] 1. First, place 500 g of the metal arsenide prepared in Example 7 in a reaction device. Gas replacement of the reaction device is carried out by vacuum pumping and nitrogen supplementation. The vacuum degree of the device is reduced to 100 Pa during the last vacuum pumping.

[0417] 2. Control the addition of sulfuric acid through a liquid inlet device. The addition rate of sulfuric acid is controlled at 250 mL / min. The sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 10%. The amount of arsine gas generated is about 4 L / min. Arsine gas is continuously generated during the reaction and enters the backend drying and water removal device. The reaction time is 60 min. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.3 mol / L.

[0418] 3. Set the temperature of the drying and water removal device to 80°C. As a result, the generation rate of arsine gas is too fast, and impurities such as moisture cannot be dried and removed in the drying and water removal device. The moisture content of the finally obtained crude arsine gas (>0.6%) does not meet the requirements.

[0419] Comparative Example 13

[0420] Compared with Example 15, only Step 3 is changed; that is, the drying and water removal device is not started:

[0421] 1. First, place 500 g of the metal arsenide prepared in Example 7 in a reaction device. Conduct gas replacement on the reaction device by evacuating and replenishing nitrogen. The last evacuation reduces the vacuum degree of the device to 100 Pa.

[0422] 2. Control the addition of sulfuric acid through a liquid inlet device. The addition rate of sulfuric acid is controlled at 50 mL / min. Sulfuric acid exists in the form of a sulfuric acid solution with a mass concentration of 10%. The amount of arsine gas generated is approximately 1 L / min. Arsine gas is continuously generated during the reaction and enters the backend drying and water removal device. The reaction time is 60 min. In the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.3 mol / L.

[0423] 3. Do not turn on the drying and water removal device. As a result, moisture and other impurities in the arsine gas cannot be dried and removed in the drying and water removal device. The moisture content of the finally obtained crude arsine gas (>2.1%) does not meet the requirements.

[0424] Comparative Example 14

[0425] Compared with Comparative Example 5, only change the vacuum condition in Step 2:

[0426] 1. First, place 100 g of the second-purity crude arsenic prepared in Example 3 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder by mass of the second-purity crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0427] 2. Seal the vacuum container with the mixture without evacuating (i.e., at normal pressure), and place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 700 °C and the reaction time at 6 h. Since no vacuum environment is set, under these conditions, the melting and boiling points of the reactants are relatively high, and the melting reaction does not proceed completely due to too low a temperature, and the final product shows a two-phase structure of separate elemental arsenic and zinc, so the metal arsenide block after the reaction cannot be obtained.

[0428] Analysis Example 1

[0429] Analysis of the metal arsenide parameters used in Examples 15 - 17 and Comparative Examples 11 - 13. The total impurity content of the metal arsenide is <0.1%, and it is a 3N-grade metal arsenide. The oxygen content is less than 0.2%, the particle size is 30 mesh, the arsenic content in the main component is 30.2%, and the zinc content is 69.2%.

[0430] Analysis Example 2

[0431] The analysis of the parameters related to the preparation of arsine in Examples 15 to 17 and Comparative Examples 11 to 13 shows that the control of the reaction vacuum environment, the regulation of the addition rate of sulfuric acid, and the drying and dehydration device are crucial to the preparation of arsine. By controlling the vacuum environment of the reaction, it is possible to effectively prevent moisture and oxygen in the air from affecting the reaction process, thereby improving the purity of arsine. At the same time, regulating the addition rate of sulfuric acid can ensure the smooth progress of the reaction and avoid the increase of impurities caused by the too fast generation of arsine gas. In addition, the use of the drying and dehydration device is crucial for removing moisture and other impurities in the reaction generated gas, which directly affects the quality and qualified rate of the final product.

[0432] Embodiment 19

[0433] The gaseous arsenide (mainly arsine) prepared in Example 15 is fed into a low-pressure condensation and rectification device, and the first pressure is adjusted to 0.5 MPa, the top temperature of the light removal tower is -66 to -62°C, the bottom temperature is -40 to -25°C, the top temperature of the heavy removal tower is -61 to -52°C, the bottom temperature is -30 to -15°C, and maintained for 2 hours to obtain arsine of first purity. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0434] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves, the temperature of the adsorption device (i.e., the second temperature, the same below) is 80°C, and the adsorption operation is performed for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed, and the trace impurities that have not been removed are activated.

[0435] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism (i.e., the third temperature, the same below) is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0436] Embodiment 20

[0437] Among them, compared with Example 19, Example 20 changed the top and bottom temperatures of the light-removal tower and the heavy-removal tower.

[0438] The gaseous arsenide (mainly arsine) prepared in Example 15 is sent to a low-pressure condensation distillation device, and the first pressure is adjusted to 0.5 MPa, the top temperature of the light removal tower is -76 to -72°C, the bottom temperature is -40 to -35°C, the top temperature of the heavy removal tower is -70 to -63°C, the bottom temperature is -30 to -23°C, and maintained for 2 hours to obtain first purity arsine. This process effectively removes high boiling point and low boiling point impurities in arsine.

[0439] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0440] Introduce arsine with a second purity into a heating mechanism. The temperature of the heating mechanism is 150 °C, and the heating duration of the heating mechanism is 2 hours to obtain an electronic-grade gaseous arsenic compound product with a product purity reaching 7N.

[0441] Example 21

[0442] Among them, compared with Example 19, Example 21 changes the first pressure.

[0443] Feed the gaseous arsenic compound (mainly composed of arsine) prepared in Example 15 into a low-pressure condensation rectification device. Regulate the first pressure to 0.4 MPa, the top temperature of the de-light tower is -66~-62 °C, the bottom temperature is -40~-25 °C, the top temperature of the de-heavy tower is -61~-52 °C, and the bottom temperature is -30~-15 °C. Maintain for 2 hours to obtain arsine with a first purity. This process effectively removes high-boiling and low-boiling impurities in arsine.

[0444] Feed the arsine with a first purity into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device is 80 °C, and an adsorption operation is carried out for 2 hours to obtain arsine with a second purity. Effectively remove impurities with a small molecular kinetic diameter and activate trace impurities that have not been removed.

[0445] Introduce arsine with a second purity into a heating mechanism. The temperature of the heating mechanism is 150 °C, and the heating duration of the heating mechanism is 2 hours to obtain an electronic-grade gaseous arsenic compound product with a product purity reaching 7N.

[0446] Example 22

[0447] Among them, compared with Example 19, Example 22 changes the first pressure.

[0448] Feed the gaseous arsenic compound (mainly composed of arsine) prepared in Example 15 into a low-pressure condensation rectification device. Regulate the first pressure to 0.2 MPa, the top temperature of the de-light tower is -66~-62 °C, the bottom temperature is -40~-25 °C, the top temperature of the de-heavy tower is -61~-52 °C, and the bottom temperature is -30~-15 °C. Maintain for 2 hours to obtain arsine with a first purity. This process effectively removes high-boiling and low-boiling impurities in arsine.

[0449] Feed the arsine with a first purity into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device is 80 °C, and an adsorption operation is carried out for 2 hours to obtain arsine with a second purity. Effectively remove impurities with a small molecular kinetic diameter and activate trace impurities that have not been removed.

[0450] Introduce arsine with a second purity into a heating mechanism. The temperature of the heating mechanism is 150 °C, and the heating duration of the heating mechanism is 2 hours to obtain an electronic-grade gaseous arsenic compound product with a product purity reaching 7N.

[0451] Example 23

[0452] Among them, compared with Example 19, the adsorbent type was changed in Example 23.

[0453] The gaseous arsenide (mainly arsine) prepared in Example 15 was sent into a low-pressure condensation rectification device, the first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66 to -62 °C, the bottom temperature was -40 to -25 °C, the top temperature of the heavy component removal column was -61 to -52 °C, and the bottom temperature was -30 to -15 °C, and it was maintained for 2 hours to obtain arsine of the first purity. This process effectively removes high-boiling and low-boiling impurities in arsine.

[0454] The arsine of the first purity was sent into an adsorption device filled with pore-adjusted activated carbon. The temperature of the adsorption device was 80 °C, and an adsorption operation was carried out for 2 hours to obtain arsine of the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0455] The arsine of the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 150 °C, and the heating duration of the heating mechanism was 2 hours to obtain an electronic-grade gaseous arsenide product, and the product purity reached the standard of 7N.

[0456] Example 24

[0457] Among them, compared with Example 19, the temperature of the heating mechanism was changed in Example 24.

[0458] The gaseous arsenide (mainly arsine) prepared in Example 15 was sent into a low-pressure condensation rectification device, the first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66 to -62 °C, the bottom temperature was -40 to -25 °C, the top temperature of the heavy component removal column was -61 to -52 °C, and the bottom temperature was -30 to -15 °C, and it was maintained for 2 hours to obtain arsine of the first purity. This process effectively removes high-boiling and low-boiling impurities in arsine.

[0459] The arsine of the first purity was sent into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device was 80 °C, and an adsorption operation was carried out for 2 hours to obtain arsine of the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0460] The arsine of the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 100 °C, and the heating duration of the heating mechanism was 2 hours to obtain an electronic-grade gaseous arsenide product, and the product purity reached the standard of 7N.

[0461] Example 25

[0462] Among them, compared with Example 19, the adsorbent type was changed in Example 25.

[0463] The gaseous arsenide (mainly arsine) prepared in Example 15 was fed into a low-pressure condensation rectification device. The first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66~-62 °C, the bottom temperature was -40~-25 °C, the top temperature of the heavy component removal column was -61~-52 °C, and the bottom temperature was -30~-15 °C. This was maintained for 2 hours to obtain arsine of the first purity. This process effectively removed high-boiling and low-boiling impurities in the arsine.

[0464] The arsine of the first purity was fed into an adsorption device filled with 4A molecular sieve. The temperature of the adsorption device was 80 °C, and an adsorption operation was carried out for 2 hours to obtain arsine of the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0465] The arsine of the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 150 °C, and the heating duration of the heating mechanism was 2 hours to obtain an electronic-grade gaseous arsenide product, and the product purity reached the standard of 7N.

[0466] Example 26

[0467] Among them, compared with Example 19, Example 26 changed the type of adsorbent.

[0468] The gaseous arsenide (mainly arsine) prepared in Example 15 was fed into a low-pressure condensation rectification device. The first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66~-62 °C, the bottom temperature was -40~-25 °C, the top temperature of the heavy component removal column was -61~-52 °C, and the bottom temperature was -30~-15 °C. This was maintained for 2 hours to obtain arsine of the first purity. This process effectively removed high-boiling and low-boiling impurities in the arsine.

[0469] The arsine of the first purity was fed into an adsorption device filled with 5A molecular sieve. The temperature of the adsorption device was 80 °C, and an adsorption operation was carried out for 2 hours to obtain arsine of the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0470] The arsine of the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 150 °C, and the heating duration of the heating mechanism was 2 hours to obtain an electronic-grade gaseous arsenide product, and the product purity reached the standard of 7N.

[0471] Example 27

[0472] Among them, compared with Example 19, Example 27 changed the temperature of the adsorption device.

[0473] The gaseous arsenide (mainly arsine) prepared in Example 15 was fed into a low-pressure condensation rectification device. The first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66 to -62 °C, the bottom temperature was -40 to -25 °C, the top temperature of the heavy component removal column was -61 to -52 °C, and the bottom temperature was -30 to -15 °C. This was maintained for 2 hours to obtain arsine with the first purity. This process effectively removed high-boiling and low-boiling impurities in the arsine.

[0474] The arsine with the first purity was fed into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device was 50 °C, and an adsorption operation was carried out for 2 hours to obtain arsine with the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0475] The arsine with the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 150 °C, and the heating duration of the heating mechanism was 2 hours to obtain an electronic-grade gaseous arsenide product, and the product purity reached the standard of 7N.

[0476] Comparative Example 15

[0477] Among them, in Comparative Example 15 compared with Example 19, the temperature of the heating mechanism was changed.

[0478] The gaseous arsenide (mainly arsine) prepared in Example 15 was fed into a low-pressure condensation rectification device. The first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66 to -62 °C, the bottom temperature was -40 to -25 °C, the top temperature of the heavy component removal column was -61 to -52 °C, and the bottom temperature was -30 to -15 °C. This was maintained for 2 hours to obtain arsine with the first purity. This process effectively removed high-boiling and low-boiling impurities in the arsine.

[0479] The arsine with the first purity was fed into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device was 80 °C, and an adsorption operation was carried out for 2 hours to obtain arsine with the second purity. Small molecule kinetic diameter impurities were effectively removed, and trace impurities that were not removed were activated.

[0480] The arsine with the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 50 °C, and the heating duration of the heating mechanism was 2 hours to obtain an arsine product, and the product purity was 4N. Since the temperature of the heating mechanism was too low, the stibine impurities were not completely removed, resulting in a decrease in the product purity.

[0481] Comparative Example 16

[0482] Among them, in Comparative Example 16 compared with Example 19, the temperature of the adsorption device was changed.

[0483] The gaseous arsenide (mainly arsine) prepared in Example 15 was fed into a low-pressure condensation rectification device. The first pressure was regulated to 0.5 MPa, the top temperature of the light component removal column was -66~-62 °C, the bottom temperature was -40~-25 °C, the top temperature of the heavy component removal column was -61~-52 °C, and the bottom temperature was -30~-15 °C. This was maintained for 2 hours to obtain arsine of the first purity. This process effectively removed high-boiling and low-boiling impurities in the arsine.

[0484] The arsine of the first purity was fed into an adsorption device filled with 3A molecular sieve. The temperature of the adsorption device was at room temperature (25 °C), and an adsorption operation was carried out for 2 hours to obtain arsine of the second purity.

[0485] The arsine of the second purity was passed into a heating mechanism. The temperature of the heating mechanism was 150 °C, and the heating duration of the heating mechanism was 2 hours to obtain an arsine product. Since the temperature of the adsorption device was relatively low, trace impurities were not fully activated, resulting in a decrease in the efficiency of pyrolyzing the unactivated trace impurities by the heating mechanism. The final product purity was 6N.

[0486] Among them, Figure 8 is a schematic diagram of the operation process of Examples 19~27 of this application, Figure 9 is a schematic diagram of the rectification mechanism of this application. Table 3 shows the boiling points of arsine and main impurities in arsine, and Table 4 shows the relevant parameters for the purification of gaseous arsenides in Examples 19~27 and Comparative Examples 15~16.

[0487] Table 3 Boiling points of arsine and main impurities in arsine

[0488]

[0489] Table 4 Relevant parameters for the purification of gaseous arsenides in Examples 19~27 and Comparative Examples 15~16

[0490]

[0491] Combining the data in Table 3 and Table 4, it can be seen that by regulating the top temperature of the light component removal column, the first pressure, the type of adsorbent, the temperature of the adsorption device, and the temperature of the heating mechanism, and then coordinating to control the bottom temperature of the light component removal column and the top and bottom temperatures of the heavy component removal column within a suitable range, all within the first temperature range, the purification of gaseous arsenides was achieved, and an electronic-grade gaseous arsenide with a purity of about 7N was obtained. These key factors have a significant impact on the purity of arsine.

[0492] Among them, the first temperature is -80 °C~-10 °C; the first pressure is 0.1 MPa~0.6 MPa.

[0493] Examples 19 to 22 demonstrated the effectiveness of the reaction conditions and equipment coordination in impurity removal through optimization of the top temperature of the light removal tower and the first pressure. Among them, compared with Example 19, the top temperature of the light removal tower in Example 20 was lower, but the antimony removal rates were not significantly different; compared with Example 19, the first pressure in Example 21 decreased, and the corresponding antimony removal rates were similar, while the silicon and sulfur removal rates slightly increased. All these indicated that by controlling the appropriate top temperature of the light removal tower and the first pressure, low-boiling impurities such as methane, ethane, or silane and most high-boiling impurities such as stibine could be effectively removed at low temperature and low pressure.

[0494] Compared with Example 19, Examples 23 and 25 to 26 changed the type of adsorbent. From the corresponding results in Table 4, by adjusting the top temperature of the light removal tower, the first pressure, and the temperature of the heating mechanism to appropriate ranges, and using 3A molecular sieve, 4A molecular sieve, or 5A molecular sieve as the adsorbent, hydrogen sulfide impurities could be removed and drying could be achieved, resulting in second-purity arsine. At the same time, the temperature of the adsorption device was the second temperature of 50 - 80°C, and other thermodynamically unstable impurities could be simultaneously activated.

[0495] Compared with Example 19, in Example 24, although the temperature of the heating mechanism decreased, the corresponding antimony removal rates were not significantly different, and the sulfur and silicon removal rates increased. This further illustrated that by coordinating the adjustment of the temperature of the heating mechanism, thermodynamically unstable impurities remaining in the distillation device and the adsorption device, such as a small amount of stibine, oxygen, carbon dioxide, nitrogen, or germanium hydride, could be effectively removed, obtaining an electronic-grade gaseous arsenide product with a purity of 7N.

[0496] The results of Comparative Examples 15 to 16 showed that when the optimal reaction conditions were not controlled, the impurity content in arsine increased significantly. For example, in Comparative Example 15, the temperature of the heating mechanism was too low to remove thermodynamically unstable impurities; in Comparative Example 16, the temperature of the adsorption device was only at room temperature (25°C), so trace impurities were not fully activated, resulting in a decrease in the efficiency of the pyrolysis device and a final product purity of 6N.

[0497] In summary, in Example 19, by adjusting the first pressure to 0.5 MPa, the top temperature of the light removal tower to -66 to -62°C, the bottom temperature to -40 to -25°C, the top temperature of the heavy removal tower to -61 to -52°C, and the bottom temperature to -30 to -15°C, maintaining for 2 hours, using 3A molecular sieve as the adsorbent, the second temperature of 80°C and performing an adsorption operation for 2 hours, and the temperature of the heating mechanism being 150°C with a heating duration of 2 hours, a relatively optimal electronic-grade gaseous arsenide product could be obtained. Among them, the antimony removal rate was 99.994%, the silicon removal rate was 99.2%, the sulfur removal rate was 87.2%, and the purity of the electronic-grade gaseous arsenide was 7N, showing excellent impurity removal effects. This provided a strong basis for further optimizing the preparation process of electronic-grade arsine.

[0498] Example 28

[0499] Feed 500 g of electronic-grade arsine prepared in Example 19 into a pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the temperature of catalytic pyrolysis is 200 °C, and the duration of catalytic pyrolysis is 1 hour.

[0500] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0501] Feed the arsine after catalytic pyrolysis into a condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 286.2 g of high-purity arsenic, and the yield is 57.2%.

[0502] Transfer the high-purity arsenic to the glove box under the protection of argon gas tightness, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0503] Example 29

[0504] Among them, compared with Example 28, Example 29 changes the temperature of catalytic pyrolysis.

[0505] Feed 500 g of electronic-grade arsine prepared in Example 19 into a pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the temperature of catalytic pyrolysis is 150 °C, and the duration of catalytic pyrolysis is 1 hour.

[0506] Among them, the flow rate of the gas flow in the pyrolysis device (that is, the flow rate of the gaseous arsenic compound flowing in the form of a gas flow bundle, the same below) is 1 L / min / cm 2 .

[0507] Feed the arsine after catalytic pyrolysis into a condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 253.7 g of high-purity arsenic, and the yield is 50.7%.

[0508] Transfer the high-purity arsenic to the glove box under the protection of argon gas tightness, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0509] Example 30

[0510] Among them, compared with Example 28, Example 30 changes the temperature of catalytic pyrolysis.

[0511] Feed 500 g of electronic-grade arsine prepared in Example 19 into a pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the temperature of catalytic pyrolysis is 250 °C, and the duration of catalytic pyrolysis is 1 hour.

[0512] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0513] The arsine after catalytic cracking is sent into the condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 289.2 g of high-purity arsenic with a yield of 57.8%.

[0514] The high-purity arsenic is transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm and the purity of the high-purity arsenic is >7N.

[0515] Example 31

[0516] Among them, compared with Example 28, Example 31 changes the temperature of catalytic cracking.

[0517] 500 g of electronic-grade arsine prepared in Example 19 is sent into the pyrolysis device, adding 5% of the mass of arsine of copper oxide as a catalyst. The temperature of catalytic cracking is 300 °C and the duration of catalytic cracking is 1 hour.

[0518] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0519] The arsine after catalytic cracking is sent into the condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 291.7 g of high-purity arsenic with a yield of 58.3%.

[0520] The high-purity arsenic is transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm and the purity of the high-purity arsenic is >7N.

[0521] Example 32

[0522] Among them, compared with Example 28, Example 32 changes the flow rate of the gas flow.

[0523] 500 g of electronic-grade arsine prepared in Example 19 is sent into the pyrolysis device, adding 5% of the mass of arsine of copper oxide as a catalyst. The temperature of catalytic cracking is 200 °C and the duration of catalytic cracking is 1 hour.

[0524] Among them, the flow rate of the gas flow in the pyrolysis device is 2 L / min / cm 2 .

[0525] The arsine after catalytic cracking is sent into the condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 196.5 g of high-purity arsenic with a yield of 39.3%.

[0526] Transfer the high-purity arsenic to the glove box under the airtight protection of argon gas, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0527] Example 33

[0528] Among them, compared with Example 28, Example 33 changes the type of catalyst.

[0529] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add silver oxide accounting for 5% of the mass of arsine as the catalyst, set the temperature of catalytic pyrolysis to 200 °C, and the duration of catalytic pyrolysis to 1 hour.

[0530] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0531] Feed the arsine after catalytic pyrolysis into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 81.5 g of high-purity arsenic, and the yield is 16.3%.

[0532] Transfer the high-purity arsenic to the glove box under the airtight protection of argon gas, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0533] Example 34

[0534] Among them, compared with Example 28, Example 34 changes the type of catalyst.

[0535] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add nickel oxide accounting for 5% of the mass of arsine as the catalyst, set the temperature of catalytic pyrolysis to 200 °C, and the duration of catalytic pyrolysis to 1 hour.

[0536] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0537] Feed the arsine after catalytic pyrolysis into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 67.7 g of high-purity arsenic, and the yield is 13.5%.

[0538] Transfer the high-purity arsenic to the glove box under the airtight protection of argon gas, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0539] Example 35

[0540] Among them, compared with Example 1, Example 35 changes the mass of the catalyst.

[0541] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add copper oxide accounting for 10% of the mass of arsine as a catalyst, the temperature of catalytic pyrolysis is 200 °C, and the duration of catalytic pyrolysis is 1 hour.

[0542] The flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0543] Feed the arsine after catalytic pyrolysis by the catalyst into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 292.7 g of high-purity arsenic, and the yield is 58.5%.

[0544] Transfer the high-purity arsenic to the glove box under argon airtight protection, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0545] Comparative Example 17

[0546] Among them, compared with Example 28, Comparative Example 17 changed the temperature of catalytic pyrolysis.

[0547] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the temperature of catalytic pyrolysis is 80 °C, and the duration of catalytic pyrolysis is 1 hour.

[0548] The flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0549] Feed the arsine after catalytic pyrolysis into the condensation device, the condensation temperature is 30 °C, and the condensation duration is 1 hour to obtain an arsenic product.

[0550] Transfer the high-purity arsenic to the glove box under argon airtight protection, and then encapsulate it with an electronic-grade packaging bag.

[0551] However, due to the low temperature of catalytic pyrolysis, only 13.7 g of the final arsenic product is finally obtained, the yield is 2.7%, and the purity is only 5N.

[0552] Comparative Example 18

[0553] Among them, compared with Example 28, Comparative Example 18 omitted the step of feeding into the pyrolysis device.

[0554] Directly feed 500 g of electronic-grade arsine prepared in Example 19 into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain an arsenic product.

[0555] Transfer the arsenic product to the glove box under argon airtight protection, and then encapsulate it with an electronic-grade packaging bag.

[0556] Due to the lack of a pyrolysis device, arsine was not fully decomposed, and finally only 1.2 g of arsenic product was obtained, with a yield of 0.24% and a purity reaching only 4N level, which could not meet the application requirements of high-purity arsenic.

[0557] Comparative Example 19

[0558] Among them, in Comparative Example 19 compared with Example 28, the airtight atmosphere was omitted.

[0559] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the catalytic pyrolysis temperature is 200 °C, and the catalytic pyrolysis duration is 1 hour.

[0560] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0561] Feed the arsine after catalytic pyrolysis into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 279.2 g of high-purity arsenic, with a yield of 55.8%.

[0562] Directly transfer the arsenic product into the glove box, and then encapsulate it with an electronic-grade packaging bag.

[0563] Since it was directly transferred to the glove box without an airtight atmosphere and contacted the external environment and oxygen during the transfer process, the product purity decreased to 5N, the oxygen content > 1.5%, and the product quality did not meet the requirements.

[0564] Comparative Example 20

[0565] Among them, in Comparative Example 20 compared with Example 28, the catalyst type was changed.

[0566] Feed 500 g of electronic-grade arsine prepared in Example 19 into the pyrolysis device, add palladium metal accounting for 5% of the mass of arsine as a catalyst, the catalytic pyrolysis temperature is 200 °C, and the catalytic pyrolysis duration is 1 hour.

[0567] Among them, the flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0568] Feed the arsine after catalytic pyrolysis into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 23.2 g of high-purity arsenic, with a yield of 4.6%.

[0569] Transfer the high-purity arsenic into the glove box under argon gas tight protection, and then encapsulate it with an electronic-grade packaging bag.

[0570] Due to the poor catalytic pyrolysis effect of adding the catalyst, the catalytic pyrolysis of gaseous arsenic compounds is incomplete, and only a very small amount of 5N-level arsenic product is obtained.

[0571] Comparative Example 21

[0572] Among them, compared with Example 28, the catalyst was omitted in Comparative Example 21.

[0573] 500 g of electronic-grade arsine prepared in Example 19 was fed into the pyrolysis device. Without adding a catalyst, the pyrolysis temperature was 200 °C, and the pyrolysis duration was 1 hour.

[0574] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 。

[0575] The arsine after pyrolysis was fed into the condensation device. The condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 13.9 g of arsenic product, and the yield was 2.9%.

[0576] The arsenic product was transferred into the glove box under the protection of argon tight seal, and then packaged with an electronic-grade packaging bag.

[0577] Due to the absence of a catalyst, the pyrolysis of gaseous arsenic compounds was incomplete, and only a very small amount of 5N-grade arsenic product was obtained.

[0578] Comparative Example 22

[0579] Among them, compared with Example 28, the catalytic pyrolysis temperature was changed and the catalyst was omitted in Comparative Example 22.

[0580] 500 g of electronic-grade arsine prepared in Example 19 was fed into the pyrolysis device. Without adding a catalyst, the pyrolysis temperature was 500 °C, and the pyrolysis duration was 1 hour.

[0581] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 。

[0582] The arsine after pyrolysis was fed into the condensation device. The condensation temperature was 400 °C, and the condensation duration was 1 hour, obtaining 238.5 g of arsenic product, and the yield was 47.7%.

[0583] The arsenic product was transferred into the glove box under the protection of argon tight seal, and then packaged with an electronic-grade packaging bag.

[0584] Due to the absence of a catalyst and the relatively high pyrolysis temperature, although it can promote the pyrolysis of arsine, it is difficult to synchronously process other thermal impurities that are relatively stable at high temperatures, such as hydrogen sulfide. Finally, only a small amount of 6N-grade arsenic product was obtained.

[0585] Among them, Figure 10Schematic diagram of the operation process for Embodiments 28 to 35 of the present application. Table 5 shows the corresponding data of the industry-related standards for high-purity arsenic products; Table 6 shows the analysis of relevant parameters of the high-purity arsenic prepared in Embodiments 28 to 35 and the arsenic products prepared in Comparative Examples 17 to 22.

[0586] Table 5 Corresponding data of the industry-related standards for high-purity arsenic products

[0587]

[0588] Table 6 Analysis of relevant parameters of the high-purity arsenic prepared in Embodiments 28 to 35 and the arsenic products prepared in Comparative Examples 17 to 22

[0589]

[0590] As shown in Table 5 and Table 6, it can be seen from the results of Embodiments 28 to 35 that the precise control of the catalytic cracking temperature has a significant impact on the purity of high-purity arsenic. In Embodiment 28, when the catalytic cracking temperature was 200 °C and with a reasonable heating time, the catalytic cracking of arsine into gaseous high-purity arsenic was successfully achieved and then converted into solid high-purity arsenic through a condensation device. Especially in Embodiment 29, although the catalytic cracking temperature was reduced to 150 °C, the purity of the high-purity arsenic product could still be maintained, further proving the effectiveness of adding a suitable catalyst and at an appropriate catalytic cracking temperature for the full pyrolysis of arsine, and the purity of the arsine product > 7N. In addition, the type of catalyst has a significant impact on the yield of high-purity arsenic prepared by the catalytic cracking of arsine. Through the comparison of Embodiment 28, Embodiment 33, and Embodiment 34, it was found that when the catalyst was copper oxide and the catalytic cracking temperature was 200 °C, the highest yield of high-purity arsenic was shown, with a yield of 57.2%, which was significantly higher than the yields of high-purity arsenic obtained by the other two metal oxide catalysts, indicating that the selection of the catalyst type is crucial. In Embodiment 35 compared with Embodiment 28, the mass of the catalyst was increased, resulting in a yield of high-purity arsenic of 58.5%, indicating that adding an appropriate mass of catalyst, combined with factors such as the catalytic cracking temperature and the catalyst type, can improve the yield of high-purity arsenic.

[0591] The results of Comparative Examples 17 to 19 showed that when the optimal catalytic pyrolysis temperature was not controlled, the purity of the arsenic product decreased significantly. In Comparative Example 17, the catalytic cracking temperature was 80 °C, but due to the too low temperature, the pyrolysis of gaseous arsenic compounds was insufficient, and the final product was only of 5N purity. And in Comparative Example 20, palladium metal was used as the catalyst, with poor catalytic effect, and the full pyrolysis of arsine and the effective removal of impurities could not be achieved, further demonstrating the importance of the selection of the catalyst type for the cracking of arsine into high-purity arsenic.

[0592] The results of Comparative Examples 21 to 22 show that without adding a catalyst, the pyrolysis rate is slow, resulting in incomplete decomposition of arsine and ineffective removal of impurities, and the purity of the final product is relatively low. Especially under the experimental conditions of not adding a catalyst at 200 °C, the pyrolysis reaction hardly occurs. Even when the temperature of catalytic pyrolysis is increased to 500 °C, the product purity also decreases significantly, indicating the importance of the choice of catalyst type and the temperature of catalytic pyrolysis in the pyrolysis of gaseous arsenides to high-purity arsenic. From the above-mentioned examples, it can be seen that in Example 28, the temperature of catalytic cracking is 200 °C, the condensation temperature is 100 °C, and the flow rate of the gas stream in the pyrolysis device is 1 L / min / cm 2 , high-purity arsenic products can be obtained, with the total impurity content <0.1 ppm and the purity of high-purity arsenic > 7N. This provides a strong basis for further optimizing the preparation process of high-purity arsenic, and at the same time emphasizes the importance of appropriate temperature control during pyrolysis and its effect on impurity removal.

[0593] In summary, in the above technical solutions of the present invention, the above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention. Any equivalent structural transformation made by using the content of the specification and drawings of the present invention under the technical concept of the present invention, or direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A method for extracting high-purity arsenic from arsenic-containing hazardous waste, characterized in that: The following steps are involved: S1, purifying the arsenic-containing hazardous waste to obtain crude arsenic of the first purity; S2, mixing crude arsenic of first purity, a first reducing agent and a purifying agent, and sublimating them in a high vacuum environment to obtain crude arsenic of second purity; wherein the first reducing agent includes one or more of zinc powder, iron powder, magnesium powder, and carbon powder; the purifying agent includes one or more of copper powder, cadmium powder, lead powder, and sulfuric acid; the high vacuum environment is a first vacuum environment, and the vacuum pressure of the first vacuum environment is not greater than 1Pa; S3, mixing the second purity crude arsenic with a metal material, and performing a melting reaction under a high vacuum condition to prepare a metal arsenide; S4, reacting the metal arsenide with the acid solution to generate a gaseous arsenide; S5, deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide; S6, pyrolyzing and condensing the electronic grade gaseous arsenic to obtain high purity arsenic.

2. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: In the step S1, the arsenic-containing hazardous waste is purified by mixing with iron powder and roasting; wherein the roasting temperature of the reaction zone is 550-700°C, and the roasting temperature of the receiving zone is 300-500°C.

3. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: The step S2 comprises: A mixed arsenic material of first purity crude arsenic, a first reducing agent and a purifying agent is placed in a hot end of a closed high vacuum environment for sublimation, and condensate at a cold end in the high vacuum environment is collected to obtain second purity crude arsenic.

4. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 3, characterized in that: In step S2, the temperature of the hot end is 600-900°C, and the temperature difference between the hot end and the cold end is not less than 200°C; the temperature of the cold end is 400-700°C.

5. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 3, characterized in that: The vacuum pressure of the first vacuum environment is 0.001~0.1Pa.

6. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: In step S3, the high vacuum condition is a second vacuum environment, the vacuum pressure of the second vacuum environment is 0.001-1 Pa, the temperature of the melting reaction is not less than 750° C., and the reaction time is not less than 5 hours.

7. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 6, characterized in that: The metal material includes one of magnesium material, zinc material and aluminum material, and the mass ratio of the second purity crude arsenic to the metal material is 1:1.3-1:1.

8.

8. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: The acid solution is sulfuric acid, and step S4 comprises: The metal arsenide is mixed with sulfuric acid in a third vacuum environment, the temperature of the sulfuric acid is maintained at 20-40° C. in the third vacuum environment, and gaseous arsenide is obtained through a gas generation reaction.

9. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 8, characterized in that: The vacuum pressure of the third vacuum environment is 1-100 Pa; in the reaction solution formed by mixing the metal arsenide and the acid solution, the concentration of the metal arsenide is 0.1-0.5 mol / L.

10. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 8, characterized in that: The step S4 further includes at least one of the following operations (1) to (2): (1) drying and removing water from the gaseous arsenide at a temperature of 0 to 100° C.; (2) Removing the gaseous arsenide to maintain the vacuum pressure of the third vacuum environment.

11. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: The step S5 comprises: placing gaseous arsenide under the conditions of a first temperature and a first pressure for distillation, collecting gaseous substances, and obtaining arsine of a first purity; Passing the first purity arsine into an adsorbent at a second temperature to remove gas impurities and drying to obtain second purity arsine; the second temperature is 50-80° C.; The second purity arsine is then heated at a third temperature to purify the gas, thereby obtaining electronic grade gaseous arsenide; the third temperature is 100-200°C.

12. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 11, characterized in that: In the step S5, at least one of the following conditions (1) to (2) is also included: (1) The adsorbent is at least one of pore-adjusting carbon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve and activated alumina; (2) The first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

13. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 11, characterized in that: The step of subjecting the gaseous arsenide to distillation under the conditions of a first temperature and a first pressure comprises: The gaseous arsenide is placed in a light-removal tower under the conditions of a first temperature and a first pressure for rectification; wherein, in the light-removal tower, the tower bottom temperature is 20-40° C. higher than the tower top temperature; The bottom material after distillation in the light-removal tower is placed in a heavy-removal tower under the conditions of a first temperature and a first pressure for distillation, and the material at the top of the tower is collected to obtain arsine with a first purity; wherein, in the heavy-removal tower, the bottom temperature is 20-40°C higher than the top temperature; the top temperature of the light-removal tower, the bottom temperature of the light-removal tower, the top temperature of the heavy-removal tower, and the bottom temperature of the heavy-removal tower are all within the first temperature range, and the top temperature of the heavy-removal tower is 5-10°C higher than the top temperature of the light-removal tower.

14. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 13, characterized in that: The first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa; The top temperature of the light removal tower is -80~-60°C, and the bottom temperature is -40~-20°C; The top temperature of the deweighting tower is -70 to -50°C, and the bottom temperature is -30 to -10°C.

15. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 1, characterized in that: The S6 step includes: The gaseous arsenide is condensed and collected after catalytic cracking, and the condensate formed by condensation is high-purity arsenic. The temperature of the catalytic cracking is 100°C~300°C; the gaseous arsenide is arsine gas; and the catalyst is one of the oxides corresponding to the transition metal / noble metal.

16. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 15, characterized in that: In the step S6, at least one of the following conditions (1) to (4) is also included: (1) The transition metal includes cobalt, nickel, copper or manganese; the noble metal includes gold, silver or platinum; (2) The amount of the catalyst added is 5% to 10% of the mass of the gaseous arsenic compound; (3) The temperature of the catalytic cracking is 120°C to 250°C; the duration of the catalytic cracking is 1 to 2 hours; (4) The condensation temperature is 50°C to 150°C lower than the catalytic cracking temperature; and the condensation time is 1 to 2 hours.

17. A device for extracting high-purity arsenic from hazardous waste containing arsenic, used for implementing the method for extracting high-purity arsenic from hazardous waste containing arsenic as claimed in any one of claims 1 to 16, characterized in that: The device for extracting high-purity arsenic from arsenic-containing hazardous waste comprises: A first purity crude arsenic preparation mechanism, used for purifying arsenic-containing hazardous waste to obtain first purity crude arsenic; A second purity arsenic preparation mechanism is used to mix the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimate them in a high vacuum environment to obtain the second purity crude arsenic; A metal arsenide preparation mechanism, used for mixing the second purity crude arsenic with a metal material and performing a melting reaction under a high vacuum condition to prepare the metal arsenide; A gaseous arsenide preparation mechanism, used for reacting metal arsenide with an acid solution to generate gaseous arsenide; An electronic grade gaseous arsenide preparation mechanism is used to deeply purify the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide; The high-purity arsenic preparation mechanism is used to pyrolyze and condense electronic-grade gaseous arsenic to obtain high-purity arsenic.

18. The device for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 17, characterized in that: The gaseous arsenide preparation mechanism comprises a gas reaction container, a vacuum pumping device, a protective gas source, and a drying and dehydrating device. The vacuum pumping device, the protective gas source, and the drying and dehydrating device are all connected to the gas reaction container.

19. The device for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 17, characterized in that: The electronic grade gaseous arsenide preparation mechanism comprises: A distillation mechanism, used for distilling the gaseous arsenide under the conditions of a first temperature, a first pressure and a vacuum atmosphere, collecting the gaseous substance, and obtaining a first gaseous arsenide; the temperature range of the first temperature is -80°C to 80°C; the pressure range of the first pressure is 0.4MPa to 0.6MPa; An adsorption mechanism, which has an adsorbent inside, the adsorption mechanism is connected to the distillation mechanism, and the adsorption mechanism is used to pass the first gaseous arsenide into the adsorbent to remove gas impurities and dry it to obtain a second gaseous arsenide; A catalytic pyrolysis mechanism, connected to the adsorption mechanism, the catalytic pyrolysis mechanism is used to introduce the second gaseous arsenic compound into the mechanism for catalytic pyrolysis to obtain pyrolysis gas; the duration of the catalytic pyrolysis is 1 h to 2 h; The condensation mechanism is connected to the catalytic pyrolysis mechanism, and the condensation mechanism is used to pass the pyrolysis gas into the condensation mechanism to condense and remove condensate, and the obtained gas is pure gaseous arsenide.

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