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

Abstract

The invention provides a method and a device for preparing high-purity arsenic by extracting arsenic-containing hazardous waste. The method comprises the following steps: S1, purifying the arsenic-containing hazardous waste to obtain crude arsenic with first purity; s2, mixing the first-purity crude arsenic, a first reducing agent and a purifying agent, and sublimating in a high-vacuum environment to obtain second-purity crude arsenic; s3, mixing the second-purity crude arsenic with a metal material, and carrying out a melting reaction under a high vacuum condition 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; and S6, performing pyrolysis and condensation on the electronic-grade gaseous arsenide to obtain high-purity arsenic. According to the method, the arsenic-containing dangerous waste is utilized, so that the problem of environmental arsenic pollution in the nonferrous industry is relieved, the purity and economic value of an arsenic product are remarkably improved, and the method has huge economic value and application prospect.

Description

Technical Field

[0001] The invention relates to the field of treatment of arsenic-containing hazardous waste and preparation of high-purity arsenic, and in particular to a complete preparation method and device from arsenic sulfide slag to high-purity arsenic. Background Art

[0002] As an important semiconductor material, arsenic 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 influence on its performance. However, the traditional arsenic preparation process has many limitations, especially in terms of purity, environmental protection and economic benefits.

[0003] First, 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 the device. Existing arsine preparation processes, such as direct extraction from arsenic ore or preparation by chemical synthesis, are often accompanied by complex side reactions and the introduction of impurities, resulting in insufficient purity of the final product. The treatment and utilization of arsenic-containing hazardous waste has become an urgent problem to be solved. In the process of non-ferrous metal smelting, a large amount of arsenic-containing waste residues, such as arsenic sulfide slag, are produced. If these waste residues are not properly treated, they will cause serious pollution to the environment. 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, the existing arsenic preparation process also has shortcomings 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 cost. In addition, the complex process flow also increases the investment and maintenance costs of equipment, limiting 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 high-purity arsenic from arsenic-containing hazardous waste. The method can effectively extract high-purity arsenic from arsenic-containing hazardous waste such as arsenic sulfide slag, which not only alleviates the environmental arsenic pollution problem in the non-ferrous industry, but also significantly improves the purity of arsenic products and enhances the recycling efficiency of resources.

[0005] The present application provides a method for extracting high-purity arsenic from arsenic-containing hazardous waste, comprising the following steps: S1, purifying arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0006] S2, mixing the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimating them in a high vacuum environment to obtain the second purity crude arsenic.

[0007] 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.

[0008] S4, reacting the metal arsenide with the acid solution to generate a gaseous arsenide.

[0009] S5, deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide.

[0010] S6, pyrolyzing and condensing the electronic grade gaseous arsenic to obtain high purity arsenic.

[0011] The present application also provides a device for extracting high-purity arsenic from arsenic-containing hazardous waste, which is used to implement the above-mentioned method for extracting high-purity arsenic from arsenic-containing hazardous waste. The device for extracting high-purity arsenic from arsenic-containing hazardous waste comprises: The first purity crude arsenic preparation mechanism is used to purify arsenic-containing hazardous waste to obtain first purity crude arsenic.

[0012] The second purity arsenic preparation mechanism is used for mixing the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimating them in a high vacuum environment to obtain the second purity crude arsenic.

[0013] The metal arsenide preparation mechanism is used for mixing the second purity crude arsenic with the metal material and performing a melting reaction under high vacuum conditions to prepare the metal arsenide.

[0014] The gaseous arsenide preparation mechanism is used for reacting metal arsenide with acid solution to generate gaseous arsenide.

[0015] The electronic grade gaseous arsenide preparation mechanism is used for deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain the electronic grade gaseous arsenide.

[0016] The high-purity arsenic preparation mechanism is used to pyrolyze and condense electronic-grade gaseous arsenic to obtain high-purity arsenic.

[0017] Beneficial effects of the present invention: In the above-mentioned method for extracting high-purity arsenic from arsenic-containing hazardous waste, arsenic sulfide slag is sequentially prepared to obtain first purity crude arsenic, second purity crude arsenic, metal arsenide, gaseous arsenide, and electronic grade gaseous arsenide, and finally high purity arsenic is obtained. The process adopted by 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 the preparation of high-purity arsenide semiconductor material products and other fields, meeting the urgent demand for high-quality raw materials in industries such as semiconductor electronic devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0019] Figure 1 This is a diagram showing the elemental quantitative analysis results of crude arsenic of the first purity in Example 1 of the present invention; Figure 2 This is a graph showing the determination of all element contents of crude arsenic of the first purity in Example 1 of the present invention; Figure 3 is an XRD phase analysis diagram of crude arsenic of the first purity in Example 1 of the present invention; Figure 4 This is a graph showing the total element content of the second purity crude arsenic obtained in Example 6 of the present invention; Figure 5 This is a phase diagram of metal arsenides prepared in some embodiments and comparative examples of the present invention, wherein: Figure 5 (a) is a phase analysis diagram of the metal arsenide product obtained in Example 7, Figure 5 (b) is a phase analysis diagram of the metal arsenide product obtained in Comparative Example 5, Figure 5 (c) is a phase analysis diagram of the metal arsenide product obtained in Example 9, Figure 5 (d) is a phase analysis diagram of the metal arsenide product obtained in Example 10; Figure 6 Schematic diagram of the liquid inlet device (metering pump + pneumatic ball valve) in Examples 15 to 17 of the present invention and Comparative Examples 11 to 13, wherein 10 is a first pneumatic ball valve, 20 is a metering pump, and 30 is a second pneumatic ball valve; Figure 7 This is a schematic flow chart of the method for extracting high-purity arsenic from arsenic-containing hazardous waste of the present invention; Figure 8 It is a schematic diagram of the operation flow of Examples 19 to 27 of the present application; Fig. 9 It is a structural schematic diagram of the distillation mechanism of the present application; Fig.10 Schematic diagram of the operation flow of Examples 28 to 35.

[0020] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0023] To achieve the above object, the present invention provides a method for extracting and preparing high-purity arsenic from arsenic-containing hazardous waste, the specific steps of which include: The present application provides a method for extracting high-purity arsenic from arsenic-containing hazardous waste. Figure 7 , including the following steps: S1, purifying arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0024] S2, mixing the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimating them in a high vacuum environment to obtain the second purity crude arsenic.

[0025] 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.

[0026] S4, reacting the metal arsenide with the acid solution to generate a gaseous arsenide.

[0027] S5, deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide.

[0028] S6, pyrolyzing and condensing the electronic grade gaseous arsenic to obtain high purity arsenic.

[0029] In the above-mentioned method for extracting high-purity arsenic from arsenic-containing hazardous waste, arsenic sulfide slag is sequentially prepared to obtain first purity crude arsenic, second purity crude arsenic, metal arsenide, gaseous arsenide, and electronic grade gaseous arsenide, and finally high-purity arsenic is obtained. The process adopted by 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 the fields of gas phase doping, preparation of high-purity arsenic products, etc., to meet the urgent needs of industries such as electronic devices and semiconductor materials for high-quality raw materials.

[0030] The following is a detailed description of each step S1 to S6.

[0031] The first part describes the S1 step in detail.

[0032] S1, purifying arsenic-containing hazardous waste to obtain crude arsenic of the first purity.

[0033] There are many ways to purify arsenic-containing hazardous waste, such as purifying arsenic-containing hazardous waste by mixing it with iron powder and roasting it.

[0034] The arsenic-containing hazardous waste includes arsenic sulfide slag, and also includes arsenic fly ash, arsenic alkali slag and other arsenic-containing waste slag. The following mainly takes arsenic sulfide slag as an example for explanation.

[0035] In order to improve the purification effect, arsenic-containing hazardous waste is subjected to some pretreatment before roasting, such as drying and crushing.

[0036] In some embodiments, the arsenic sulfide slag has a moisture content of 40% to 80%, and the temperature of the drying step is controlled between 70° C. and 110° C. to remove free water and bound water in the arsenic sulfide slag.

[0037] In some embodiments, the arsenic sulfide slag is dried at 90°C to optimize water removal efficiency.

[0038] 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.

[0039] The roasting step is carried out in a closed container, which has a reaction zone and a receiving zone. The reaction zone is the reaction zone of the mixture of arsenic-containing hazardous waste and iron powder. The receiving zone is the generation zone of first purity crude arsenic. The roasting temperature of the reaction zone is 550-700°C, and the roasting temperature of the receiving zone is 300-500°C, so as to remove organic sulfur and other volatile impurities in the arsenic sulfide slag.

[0040] The second part explains the S2 step in detail.

[0041] S2, mixing the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimating them in a high vacuum environment to obtain the second purity crude arsenic.

[0042] In some embodiments, the step of mixing crude arsenic of first purity, a first reducing agent, and a purifying agent, and sublimating the mixture in a high vacuum environment to obtain crude arsenic of second purity specifically includes the following steps: S21. The first purity crude arsenic, the first reducing agent and the purifying agent are mixed to obtain a mixed arsenic material.

[0043] 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 2N grade. 2N grade first purity crude arsenic is crude arsenic with an impurity content of ≤0.1% and >0.01%. In some embodiments, the first purity crude arsenic is subjected to elemental quantitative analysis. 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, and the contents can be 40-60 ppm, 4-5 ppm, and 1-2 ppm, respectively.

[0044] The first purity crude arsenic also includes a certain content of oxygen. In some embodiments, the oxygen content (mass fraction) of the first purity crude arsenic is 5-10%.

[0045] In some embodiments, the first reducing agent includes one or more of zinc powder, iron powder, and carbon powder. The amount of the first reducing agent added is 1% to 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.

[0046] In some embodiments, the purifying agent includes one or more of copper powder, cadmium powder, lead powder and sulfuric acid. The amount of the purifying agent added can be 2-10% of the mass of the first purity crude arsenic.

[0047] In some embodiments of the present invention, when the purifying agent is sulfuric acid, the concentration of the sulfuric acid may be 90-95%.

[0048] In other embodiments of the present invention, the purifying agent may include copper powder and / or sulfuric acid.

[0049] The combination of some purifying agents and the first reducing agent has a synergistic effect and has a better effect than the general purifying agent 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 purifying agent can be one of copper powder and sulfuric acid.

[0050] In some preferred embodiments, the first reducing agent may be one of carbon powder and iron powder, and the purifying agent may be copper powder.

[0051] In some more preferred embodiments, the first reducing agent is carbon powder, and the purifying agent is copper powder.

[0052] In some more preferred embodiments, the first reducing agent is carbon powder, and the purifying agent is sulfuric acid.

[0053] The present invention mixes the first purity crude arsenic with the first reducing agent, which, on the one hand, avoids the negative impact of oxidized impurities (such as high-valent arsenic oxides) 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-valent arsenic that is easier to sublimate, thereby making the purification of arsenic relatively thorough. On the other hand, the first reducing agent can create a reducing atmosphere to ensure that the arsenic is not oxidized during the sublimation process.

[0054] Purifiers 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 purifiers also enhances the chemical stability of the system, avoids the occurrence of side reactions, and ensures the specificity and efficiency of the purification process.

[0055] In some embodiments, the amount of the first reducing agent added may be 1% to 5% of the mass of the first purity crude arsenic.

[0056] S22. Place the mixed arsenic material in a sealed first high vacuum environment, wherein the first high vacuum environment includes a hot end and a cold end, wherein the mixed arsenic material sublimates at the hot end and condenses at the cold end, and crude arsenic of second purity is collected. The vacuum pressure in the first high vacuum environment is not greater than 1Pa.

[0057] It should be noted that in the present invention, vacuum pressure and vacuum degree are equivalent in meaning, that is, they express the specific apparent pressure value of gas in a vacuum environment.

[0058] In some embodiments, the vacuum degree in the first high vacuum environment is 0.001-0.1 Pa.

[0059] The main impurity of the first purity crude arsenic is antimony. Since arsenic and antimony belong to the VA group elements and have similar chemical properties, they are difficult to separate under normal conditions. However, by controlling the reaction temperature under high vacuum conditions and utilizing the significant difference in saturated vapor pressure and maximum volatilization rate between arsenic and antimony under high vacuum and low temperature conditions, the residual amount of antimony can be effectively reduced. When the appropriate reaction temperature is selected, the volatilization rate of arsenic is significantly higher than that of antimony, so that arsenic can be sublimated to the cold end first, which improves the purity of the product and reflects the innovation of the present invention.

[0060] The calculation formula for the saturated vapor pressure of each metal is: log 10 P = A T -1 + Blog 10 T + C T + D The saturated vapor pressure of each metal calculated according to the above formula is shown in Table 1: Table 1 Saturated vapor pressure of each metal The present invention adopts high vacuum technology, for example, the vacuum degree in the vacuum environment is controlled to be no more than 1Pa, and the difference between the saturated vapor pressure, volatilization rate and boiling point between arsenic and the main impurity antimony is utilized to separate the two, thereby effectively alleviating the problem of difficulty in separating impurities during the sublimation process of first-purity crude arsenic, thereby obtaining high-purity arsenic, i.e., second-purity crude arsenic.

[0061] 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 solid substances are directly converted into gas without passing through the liquid state; in a high vacuum environment, the sublimation process can be carried out more efficiently because the interference of gas molecules on the sublimation process is reduced.

[0062] During the purification process, elemental arsenic is heated to the sublimation point, and the arsenic molecules will detach from the solid surface and enter the vacuum environment. Since arsenic and antimony have different sublimation temperatures, the separation of arsenic and antimony can be achieved by precisely controlling the temperature of the hot end. In addition, the high vacuum environment also helps to reduce the oxidation and hydrolysis of arsenic during the sublimation process, thereby ensuring the chemical purity of the second-purity crude arsenic. High vacuum sublimation purification technology combined with precise temperature control and atmosphere management provides a new way to prepare high-purity elemental arsenic, which can not only improve the purity of elemental arsenic, but also reduce by-products and operational risks in the preparation process, which is of great significance for promoting the development of semiconductor material technology.

[0063] In some specific embodiments, the first purity crude arsenic, the first reducing agent, and the purifying agent can be placed in an inert atmosphere in proportion and fully ground and mixed in a mixer to obtain a mixed arsenic material. The mixed arsenic material is then placed in a vacuum container, evacuated to 0.001~0.1Pa through sealing, and then placed in a furnace structure with a hot end and a cold end for sublimation.

[0064] 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. 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.

[0065] In some specific embodiments, the temperature of the hot end may be 600-800° C., and the temperature of the cold end may be 400-600° C. In some more specific embodiments, the temperature of the hot end may be 600-700° C., and the temperature of the cold end may be 400-500° C.

[0066] For example, when the vacuum degree is 0.001 Pa, the hot end temperature can be set to 650° C. and the cold end temperature can be set to 450° C.

[0067] In the present invention, the duration of the hot end sublimation is not less than 2 hours; further, the duration of the hot end sublimation can be 2 to 8 hours; illustratively, the duration of the hot end sublimation can be 6 to 8 hours.

[0068] The mixed arsenic material is sublimated at the hot end and condensed at the cold end to collect the second purity crude arsenic, and the step also includes transferring the second purity crude arsenic to an inert atmosphere and crushing the second purity crude arsenic in turn; wherein the crushing time is 5 to 30 minutes, and the particle size of the screening treatment is 200 to 400 meshes.

[0069] The inert atmosphere can be nitrogen or argon. The crushing process is to crush the material with a crushing mill and sieve to obtain purified arsenic powder.

[0070] The crushing process can be to use a crushing mill to crush the material, and sieve to obtain purified arsenic powder. The crushing time is 5 to 30 minutes, and the sieved particle size can be 200 to 400 meshes.

[0071] The method of step S2 of the present invention has high impurity removal efficiency and deoxidation performance. By accurately 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 easy to implement in industrial production, ensuring the consistency and reliability of product quality.

[0072] The third section introduces the S3 step in detail.

[0073] 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.

[0074] In some embodiments, the second purity crude arsenic is mixed with a metal material and subjected to a melting reaction under high vacuum conditions to prepare the metal arsenide, comprising: S31: Mixing the second purity crude arsenic with the metal material to obtain an arsenic metal mixed material.

[0075] The metal material is an active metal powder, and the metal material includes one of magnesium powder, zinc powder and aluminum powder. The following description is made by taking the metal material being zinc powder as an example.

[0076] In some embodiments, the mass ratio of the second purity crude arsenic to the metal material is 1:1.3~1:1.8. Exemplarily, the mass ratio of the second purity crude arsenic to the zinc material is 1:1.3~1:1.8. In the case where the metal material is a zinc material, by precisely controlling the arsenic-metal ratio and combining the application of a vacuum environment, the efficient generation of Zn3As2 can be promoted, and the generation of byproducts As2O3 and ZnAs2 can be avoided. Vacuum conditions (0.001~1 Pa) significantly reduce the oxygen content in the environment, inhibit the formation of oxides such as As2O3, and at the same time enhance the vapor pressure of arsenic, making it easier for arsenic to react with active metals to generate Zn3As2. The appropriate arsenic-metal ratio can be fully utilized in a vacuum environment, effectively controlling the reaction selectivity, and improving the generation rate and purity of Zn3As2, thereby achieving the purpose of optimizing product quality.

[0077] In some specific embodiments, the mass ratio of the second purity crude arsenic to the zinc material may be 1:1.3.

[0078] In some specific embodiments, the second purity crude arsenic and zinc material can be placed in an inert atmosphere in proportion, and fully ground and mixed in a mixer to obtain an arsenic-zinc mixture.

[0079] 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 a metal arsenide; the vacuum degree in the vacuum container is 0.001~1Pa (i.e., the second vacuum environment); and the reaction time of the melting reaction is not less than 5 hours.

[0080] In the present invention, a second reducing agent can be added to the arsenic metal mixture before or during the melting reaction to control the second reducing agent to participate in the melting reaction; specifically, the second reducing agent can be added to the arsenic metal mixture before the melting reaction; for example, the second reducing agent and the arsenic metal mixture are mixed and placed together in the vacuum container to carry out the melting reaction.

[0081] In some embodiments of the present invention, the second reducing agent includes one or more of activated carbon, carbon black, and graphite powder; the added amount of the second reducing agent is 0.1-0.5% of the mass of the crude arsenic.

[0082] In some specific embodiments of the present invention, the second reducing agent may include activated carbon and / or graphite powder.

[0083] For example, the vacuum container may be heated to 600-1000° C. to perform a melting reaction to obtain the metal arsenide.

[0084] In some embodiments, the vacuum degree in the second vacuum environment can be 0.001~1Pa, which is a vacuum environment.

[0085] In some embodiments, the vacuum degree of the vacuum container in the second vacuum environment may be 0.001-0.01 Pa to further reduce the oxygen content and improve the purity of the product.

[0086] In the present invention, the temperature of the melt reaction in the second vacuum environment is not less than 750° C. In some embodiments, the temperature of the melt reaction may be 750° C. to 1200° C.; in some specific embodiments, the temperature of the melt reaction may be 750° C. to 1100° C.; in some more specific embodiments, the temperature of the melt reaction may be 750° C. to 1050° C.

[0087] In some preferred embodiments of the present invention, the temperature of the melt reaction can also be controlled at 750-950°C. It can be seen from thermodynamic analysis that when the temperature of the melt reaction is 750-950°C, the phase structure of the Zn3As2 system changes significantly. Especially at a temperature of around 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 reactivity than the α phase, which can effectively increase the reaction rate of arsenic and zinc and promote the formation of metal arsenides. In addition, because the β phase has a tighter crystal structure and reduces the doping of impurities, the preparation of metal arsenides using the phase transformation process near this temperature can also effectively improve its purity. Taking into account the temperature, reaction rate and phase change characteristics in the phase diagram, the reaction efficiency is low at too low a temperature (<750°C), and it is difficult to prepare high-quality zinc arsenide products without a phase change effect.

[0088] In some other preferred embodiments of the present invention, the temperature of the melting reaction can be controlled at 750°C to 850°C, and the significant difference in the saturated vapor pressure and maximum volatilization rate between arsenic and antimony is used to achieve the maximum separation of 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 belong to the same VA group elements and have similar chemical properties, they are difficult to separate under conventional conditions, which increases the complexity of purification.

[0089] Exemplarily, the temperature of the melt reaction can be controlled at 770-830°C; and further exemplary, the temperature of the melt reaction can be controlled at 780-820°C.

[0090] The reaction time of the melting reaction in step S3 is not less than 5 hours, for example, the melting reaction time can be 5 to 12 hours.

[0091] According to the morphology of the metal arsenide throughout the process, the metal arsenide includes a metal arsenide melt, a metal arsenide block and a metal arsenide particle product. Specifically: in step S3, the metal arsenide melt obtained by the melting reaction is cooled to obtain a metal arsenide block, and the metal arsenide block is crushed and sieved in an inert atmosphere to obtain a metal arsenide particle product; the particle size of the metal arsenide particle product can be 200~400 mesh.

[0092] Exemplarily, the crushing method includes ball milling, the ball milling time is 6 to 12 hours, and the sieving particle size is 200 to 400 meshes.

[0093] Also illustratively, the inert atmosphere includes one of nitrogen or argon.

[0094] 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.

[0095] Section 4 introduces the S4 step in detail.

[0096] S4, reacting the metal arsenide with the acid solution to generate a gaseous arsenide.

[0097] In some embodiments, the step of reacting the metal arsenide with the acid solution to generate the gaseous arsenide comprises: The metal arsenide is mixed with sulfuric acid in a third vacuum environment to obtain gaseous arsenide through a gas generation reaction. The gaseous arsenide includes arsine.

[0098] The sulfuric acid used in the present invention is in the form of a sulfuric acid solution, and its concentration can be 5-20%; in the embodiments and comparative examples, the sulfuric acid is provided in the form of a sulfuric acid solution, and its concentration is basically 9-11%.

[0099] In some embodiments, the vacuum degree of the third vacuum environment is 1-100 Pa.

[0100] In some embodiments, forming the third vacuum environment comprises the steps of: S41, evacuating the gas production reaction device, and then introducing inert gas into the device to normal pressure.

[0101] S42, repeat step S41 at least 2 times, such as 2 to 4 times.

[0102] S43, evacuating the device at normal pressure to 1-100 Pa to obtain the third vacuum environment. The inert gas may include nitrogen or argon.

[0103] After evacuating the system, nitrogen or argon is filled to normal pressure and the 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, so that the gas production reaction can proceed under the most ideal conditions and the occurrence of side reactions can be effectively suppressed.

[0104] For example, the vacuum degree in the gas production reaction device can be drawn to 1-50Pa.

[0105] In some embodiments, the rate of addition of sulfuric acid during the gas production reaction is 50-200 mL / min, and the rate of generation of arsine is 1-3 L / min; during implementation, the duration of the gas production reaction can be 30-120 min, preferably 40-80 min.

[0106] In other embodiments, sulfuric acid may be added into the third vacuum environment through a liquid inlet device.

[0107] The liquid inlet device may include a metering pump, and the amount of sulfuric acid added can be adjusted by controlling the stroke length of the metering pump, and the rate of sulfuric acid addition can be 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.

[0108] like Figure 6 As shown, the liquid inlet device can also be a combination of a metering pump and a pneumatic ball valve, wherein 10 is a first pneumatic ball valve, 20 is a metering pump, and 30 is a second pneumatic ball valve.

[0109] In some embodiments, the arsine generated by the gas production reaction is subjected to a dehydration treatment, comprising the steps of: passing the arsine into a drying and dehydration device, wherein the temperature of the drying and dehydration device is set to 0-100° C., and further to 50-100° C. The drying and dehydration device effectively reduces the moisture content in the arsine to a minimum, and obtains a relatively pure crude arsine gas, which is suitable for subsequent purification to prepare electronic grade high-purity arsine.

[0110] In other embodiments, a negative pressure device is provided between the third vacuum environment and the drying and dehydrating device, and the arsine gas in the third vacuum environment is sucked by the negative pressure device to maintain the vacuum degree of the third vacuum environment. The negative pressure device is used to enhance the gas production reaction trend, so that the gas production reaction can proceed to the end. Exemplarily, the negative pressure device can be a Venturi negative pressure device.

[0111] In comparison, the traditional process cannot maintain the vacuum state during the gas production reaction, which inhibits the forward progress of the gas production reaction.

[0112] In some embodiments, the gas production reaction parameters are controlled as shown in Table 2: Table 2 Parameter control during gas production reaction That is, in some embodiments, in the gas production 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 production reaction can be 20~40°C, the pH in the gas production reaction system can be 0.2~1, the duration of the gas production reaction can be 30~120min, and the reaction pressure of the gas production reaction can be 1~100Pa.

[0113] In summary, step S4 of the present invention partially and innovatively uses vacuum environment maintenance, precise control of reaction parameters and drying and water removal technology to synergistically optimize the reaction process of metal arsenide and sulfuric acid.

[0114] Specifically, first of all, a low vacuum environment is conducive to the volatilization of arsine gas. Arsine has a low boiling point and is easy to decompose or react with other substances under normal pressure. Low vacuum can reduce the partial pressure of the gas in the reactor, so that arsine can volatilize quickly 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), reducing the occurrence of side reactions. And low vacuum helps to reduce the generation of impurities. When the reaction is carried out under low vacuum, the outside air is effectively isolated, preventing arsine from undergoing oxidation reaction with oxygen in the air during the generation process, thereby reducing the formation of arsenic oxide or other oxides and ensuring the purity of arsine.

[0115] In addition, low vacuum is conducive to accelerating the reaction rate. Under low vacuum, collisions between gas molecules are more frequent, and the exchange of reactants and products is faster, thereby improving the reaction efficiency. That is, the third vacuum environment significantly reduces the concentration of moisture and oxygen in the reaction environment, reduces unnecessary side reactions, and ensures that the reaction between metal arsenide and sulfuric acid can be fully and effectively carried out. Based on this, the maintenance of the third vacuum environment ensures the positive trend of the gas production reaction. Secondly, precise control of reaction parameters can regulate the reaction process and improve the yield and purity of arsine.

[0116] Finally, the setting of the drying and dehydration device further reduced the moisture content in the generated arsine, laying the foundation for the subsequent preparation of high-purity arsine. This new and efficient preparation method can overcome many drawbacks of the traditional process, significantly improve the yield and purity of arsine, and effectively improve the quality and reaction efficiency of arsine. It is particularly suitable for large-scale production needs in the semiconductor industry, and thus has a high industrial application value, providing a more economical and efficient way for the production of electronic-grade arsine.

[0117] Section 5 introduces step S5 in detail.

[0118] S5, deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide.

[0119] In some embodiments, the step of deeply purifying the gaseous arsenide through multi-stage impurity removal to obtain electronic grade gaseous arsenide includes: S51: placing the gaseous arsenide at a first temperature and a first pressure in a distillation mechanism for distillation, collecting the gaseous substance, and obtaining arsine with a first purity.

[0120] For example, the first temperature is -80°C to -10°C. The first pressure is 0.1MPa to 0.6MPa. For example, the pressure range of the first pressure is 0.4MPa to 0.6MPa.

[0121] In some embodiments, a low-pressure condensation and rectification device is used, which contains a light-removal tower and a heavy-removal tower. By adjusting the top and bottom temperatures of the light-removal tower, the light-component gaseous substance is easily volatile and exists at the top of the light-removal tower because the boiling point of the light-component gaseous substance is lower than that of arsine. The light-component gaseous substance is separated to obtain a liquid substance, which is collected by a first gaseous recovery device. The liquid substance is collected at the bottom of the light-removal tower by a first liquid recovery device.

[0122] In some other embodiments, the light gaseous component has a boiling point lower than that of arsine, also known as a low-boiling impurity, and includes methane, ethane, or silane.

[0123] In some embodiments, a light component gas is separated out through a light removal tower to obtain a liquid. The liquid is then sent to a de-weighting tower, and by regulating the top and bottom temperatures of the de-weighting tower, the heavy component material is liquefied into a heavy component liquid because the boiling point of the heavy component material is higher than the boiling point of arsine, and is present at the bottom of the de-weighting tower. The heavy component liquid is separated to obtain arsine gas of first purity. The first purity arsine gas is at the top of the de-weighting tower and is collected by a first collector. The heavy component liquid is at the bottom of the de-weighting tower and is collected by a second liquid recovery device.

[0124] In yet other embodiments, the heavy components having a boiling point higher than that of arsine, also referred to as high-boiling impurities, include antimonane.

[0125] S52: Passing the first purity arsine into an adsorbent at a second temperature to remove gas impurities and drying to obtain second purity arsine.

[0126] In some embodiments, in the step of passing the first purity arsine into an adsorbent at a second temperature, the second temperature is 50°C to 80°C.

[0127] In some embodiments, 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. The microporous structure of the adsorbent selectively adsorbs different molecules, effectively removing small molecular kinetic diameter impurities (such as hydrogen sulfide, hydrogen, etc.) in arsine, and significantly reducing the residual impurity content in arsine.

[0128] Hydrogen sulfide and arsine have similar boiling points, but their molecular dynamic diameters are greatly different. Therefore, by passing the first-purity arsine into the adsorbent at the second temperature, impurities in the first-purity arsine, such as hydrogen sulfide and volatile organic compounds, are removed to prevent impurities from clogging the pipeline in subsequent steps and affecting the efficiency of gaseous arsine purification. 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 simultaneously activate other thermodynamically unstable impurities.

[0129] 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 be reduced. This is 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, so that the thermodynamically unstable impurities can be activated so that they are easy to decompose in S53, such as using a relatively low heating temperature or heating time; and they will not be decomposed in advance in the adsorption step, thereby avoiding the antimony generated by the premature decomposition of antimony alkane from clogging the pores of the adsorbent, reducing the adsorption effect of the adsorbent, or reducing the regeneration efficiency of the adsorbent.

[0130] S53: The second purity arsine is then heated at a third temperature to purify the gas, thereby obtaining electronic grade gaseous arsenide. In the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 100°C to 200°C.

[0131] In some embodiments, in the step of purifying the gas by heating the second purity arsine at a third temperature, the antimonane impurity is mainly removed. The gaseous arsenide is distilled to remove low-boiling impurities and most high-boiling impurities, and then introduced into the adsorbent at the second temperature to remove hydrogen sulfide and simultaneously activate other thermodynamically unstable impurities, so that the second purity arsine contains only a small amount of thermodynamically unstable impurities. Therefore, after purifying the gas by adjusting the third temperature, electronic grade gaseous arsenide is obtained.

[0132] If the third temperature is too high, arsine will be thermally decomposed, while if it is too low, antimonane impurities cannot be effectively removed. Therefore, the third temperature is adjusted to 100 ℃~200 ℃, and antimonane impurities can be removed by thermal decomposition.

[0133] In some specific embodiments, in the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 120°C to 180°C.

[0134] In general, the gas obtained by purifying the second purity arsine by heating at the third temperature is electronic grade gaseous arsenide. The specific separation principle of antimonane and electronic grade gaseous arsenide in the second purity arsine is as follows: According to DFT theoretical calculations, the arsenic-hydrogen bond dissociation energy of the main component of electronic-grade gaseous arsenide, arsine (AsH3), is 80.3 kcal / mol, and the antimony-hydrogen bond dissociation energy of antimony (SbH3) is 67.7 kcal / mol.

[0135] Convert bond breaking energy from kcal / mol to J / mol (thermal decomposition formula in SI units): 1kcal / mol=4184 J / mol.

[0136] That is, the bond breaking energy of arsenic: ΔH (AsH3) = 80.3 kcal / mol × 4184 = 336779.2 J / mol.

[0137] Antimony bond breaking energy: ΔH (SbH3) = 67.7 kcal / mol × 4184 = 283236.8 J / mol.

[0138] The pyrolysis temperature T can be approximately estimated by the formula: T=ΔH / ΔS.

[0139] Where ΔH is the enthalpy change of the reaction, corresponding to the bond breaking energy, usually expressed in kcal / mol. ΔS is the entropy increase of the molecule during the decomposition process, here expressed as 20 cal / (mol·K).

[0140] By calculating with thermodynamic formula, it can be deduced that the theoretical temperature for bond breaking in arsine is 4024 K, and the theoretical temperature for bond breaking in antimonane is 3384 K. Among them, the temperature required for breaking the antimony hydrogen bond in antimonane is lower.

[0141] It should be noted that the theoretical calculation value ignores the influence of factors such as catalyst and decomposition pressure, so the theoretical calculation temperature required for bond breaking is too high. In 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 by relevant experiments.

[0142] Although the theoretical calculation of the temperature required for bond breaking is much higher than the experimental pyrolysis temperature, it still shows that antimony hydrogen bonds are easier to decompose than arsenic hydrogen bonds at relatively lower temperatures.

[0143] According to molecular dynamics simulation calculations, at 200K, the bond length of arsine is 1.59Å; the bond length of antimonane is 1.80Å. At 700K, the bond length of arsine is 1.70Å; the bond length of antimonane is 1.95Å. Molecular dynamics simulation calculations also show that antimonane has a longer bond length than arsine and is relatively easy to decompose.

[0144] Therefore, the method of regulating the third temperature is adopted, mainly to control the decomposition and removal of antimonane to obtain electronic grade gaseous arsenide products.

[0145] In the above-mentioned method for purifying gaseous arsenide, the gaseous arsenide is placed under the conditions of a first temperature and a first pressure, and the gaseous substance obtained by distillation is collected by utilizing the difference in boiling points, which is the first purity arsine; the first purity arsine is passed into an adsorbent at a second temperature, and in addition to removing hydrogen sulfide, hydrogen and water, other thermodynamically unstable impurities are simultaneously activated to obtain the second purity arsine; and the second purity arsine is then heated at a third temperature to purify the gas, which is the electronic grade gaseous arsenide. Among them, the second purity arsine is heated at the third temperature to break the antimony hydrogen bond in antimony, thereby achieving the thermal decomposition and removal of the antimony impurities. In some embodiments, the above-mentioned impurity removal method can effectively reduce the impurity content in the gaseous arsenide to a minimum, and obtain a deeply purified ultra-high purity electronic grade gaseous arsenide.

[0146] The purity of the electronic-grade gaseous arsenide product prepared by the above-mentioned gaseous arsenide purification method reaches the electronic-grade standard, which meets the industrial production requirements of high-quality and 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 gaseous arsenide purification method.

[0147] The distillation step can be carried out by using a single distillation tower or a combination of multiple distillation towers. Exemplarily, the distillation mechanism includes a light removal tower and a heavy removal tower; the light removal tower and the heavy removal tower are connected in series. The distillation mechanism mainly separates the components by the difference in boiling points, and the low-boiling point (light) impurities and the high-boiling point (heavy) impurities are mainly separated by two-stage tower tops and tower bottoms.

[0148] Accordingly, in some embodiments, the step of subjecting the gaseous arsenide to distillation at 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 the bottom temperature of the light-removal tower is 20-60° C. higher than the top temperature of the tower.

[0149] In this step, the light-removal tower is mainly used to remove lighter impurities (such as methane, ethane, silane and other low-boiling impurities). Since the temperature at the top of the tower is relatively low, the light components can be more volatile and separated.

[0150] 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 of a first purity. Wherein, in the heavy removal tower, the tower bottom temperature is 20-60°C higher than the tower top temperature; the tower top temperature of the light removal tower, the tower bottom temperature of the light removal tower, the tower top temperature of the heavy removal tower, and the tower bottom temperature of the heavy removal tower are all within the first temperature range, and the tower top temperature of the heavy removal tower is 5-30°C higher than the tower top temperature of the light removal tower.

[0151] In this step, the deweighting tower is mainly used to remove high-boiling impurities (such as water, antimony 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 precipitation and reflux separation of the heavy components.

[0152] In some embodiments, the top temperature of the light removal tower is -80~-60°C, the bottom temperature is -40~-20°C; and the first pressure is 0.1MPa~0.6MPa.

[0153] The top temperature of the deweighting tower is -70 to -50°C, the bottom temperature is -30 to -10°C; the first pressure is 0.1 MPa to 0.6 MPa.

[0154] In some embodiments, the gaseous arsenide is prepared by uniformly mixing a metal arsenide and a sulfuric acid solution at a temperature of 20-40° C. and a vacuum pressure of 1-100 Pa.

[0155] Wherein, the metal arsenide is one of zinc arsenide, magnesium arsenide and aluminum arsenide.

[0156] 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.

[0157] In some embodiments, the first purity arsine comprises arsine and impurities; wherein the impurities contain at least one of antimonane, silane, phosphine, hydrogen sulfide, and germane.

[0158] In some embodiments, the second purity arsine contains arsine and thermodynamically unstable substances; the thermodynamically unstable substances contain at least one of oxygen, carbon dioxide, nitrogen, germane, and antimonane.

[0159] The present application also provides a gaseous arsenic purification device, comprising: The distillation mechanism is used to distill the gaseous arsenide under the conditions of a first temperature and a first pressure, collect the gaseous substance, and obtain arsine of a first purity; the first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

[0160] See also Fig. 9 , Fig. 9 The distillation mechanism of the present application is shown in the figure. The distillation mechanism includes a light removal tower top A; a light removal tower body (packing section) B; a light removal tower bottom C; a heavy removal tower top D; a heavy removal tower body (packing section) E; a heavy removal tower bottom F; number 1 is the gaseous arsenide inlet; number 2 is the low boiling point impurity outlet; number 3 is the path for the liquid to enter the heavy removal tower from the light removal tower bottom; number 4 is the first purity arsine outlet; number 5 is the high boiling point impurity outlet.

[0161] In some embodiments, the gaseous arsenide is placed in a distillation mechanism, and the light component gaseous substance is separated into a liquid substance through a light removal tower; and the heavy component liquid substance is then separated into the first purity arsine through a heavy removal tower.

[0162] In some embodiments, the distillation mechanism is a low-pressure condensation distillation device capable of regulating temperature and pressure.

[0163] In some embodiments, the gaseous arsenide is prepared by a reactor, and the reactor is directly connected to the distillation mechanism. For example, a condenser is not required between the two. The adsorption mechanism has an adsorbent inside, and the adsorption mechanism is connected to the distillation mechanism. The adsorption mechanism is used to pass the first purity arsine into the adsorbent at the second temperature to remove gas impurities and dry it to obtain the second purity arsine.

[0164] In some embodiments, the adsorption mechanism may be a straight tower filled with an adsorbent. The first purity arsine passes through the straight tower, and the adsorbent removes hydrogen sulfide and dries the gas to obtain second purity arsine.

[0165] A heating mechanism is connected to the adsorption mechanism, and is used to pass the second purity arsine into the adsorption mechanism for heating at a third temperature to obtain purified gas; the third temperature is 100°C to 200°C.

[0166] In some embodiments, the heating mechanism uses a heating kettle to remove thermodynamically unstable impurities in arsine, such as oxygen, carbon dioxide, nitrogen, germane, or antimony remaining after the distillation mechanism and adsorption mechanism steps, by heating in a closed atmosphere. Arsine exists and is collected in a gaseous state, thereby achieving the purpose of separation and impurity removal. At the same time, the control of the third temperature of the heating mechanism also avoids the thermal decomposition of arsine, further improving the purity and content of arsine.

[0167] In some embodiments, the above-mentioned gaseous arsenic purification device further includes: The first purifier includes a first gas recovery device, a first liquid recovery device, a second liquid recovery device and a first collector.

[0168] The first gas recovery device is connected to the top of the light-removing tower; the first liquid recovery device is connected to the bottom of the light-removing tower; the second liquid recovery device is connected to the bottom of the heavy-removing tower, and the first collector is connected to the top of the heavy-removing tower and the adsorption mechanism respectively.

[0169] In some embodiments, the first gaseous recoverer is used to collect the light component gaseous material; the first liquid recoverer is used to collect the liquid material; the second liquid recoverer is used to collect the heavy component liquid material; and the first collector is used to collect the first purity arsine gas.

[0170] The second purifier includes a second collector; the second collector is connected to the adsorption mechanism and the heating mechanism respectively.

[0171] In some embodiments, the second purity arsine is collected using a second collector.

[0172] The third purifier includes a second gas recovery device and a third collector.

[0173] The second gaseous recovery device is connected to the bottom outlet of the heating mechanism and is used to collect antimony or arsenic-antimony mixture, which is the product of antimonane pyrolysis; the third collector is connected to the gas phase outlet of the heating mechanism and is used to collect electronic grade gaseous arsenic.

[0174] In some embodiments, the devices in the first purifier, the second purifier and the third purifier are connected by pipelines; and the interfaces between the pipelines are connected in a sealing manner.

[0175] Exemplarily, the various devices are connected by pipelines, so that arsine and impurities can flow through the pipelines, thereby facilitating the removal of impurities.

[0176] As another example, the interfaces between the pipelines are connected in a sealed manner to ensure that the arsine gas is not lost and foreign impurities are not introduced.

[0177] Section 6 introduces step S6 in detail.

[0178] S6, pyrolyzing and condensing the electronic grade gaseous arsenic to obtain high purity arsenic.

[0179] In some embodiments, the steps include: The gaseous arsenide is condensed and collected after catalytic cracking. The condensate formed by condensation is high-purity arsenic. The temperature of the catalytic cracking is 100°C to 300°C. The gaseous arsenide is arsine gas.

[0180] After the gaseous arsenide is catalytically cracked, arsine is pyrolyzed into gaseous high-purity arsenic, and the gaseous high-purity arsenic is converted into solid high-purity arsenic through condensation, and is separated from other gaseous substances (such as unreacted gaseous arsenide, hydrogen produced by catalytic cracking, and trace impurities that may exist in the gaseous arsenide). The total impurity content of the high-purity arsenic is <0.1ppm.

[0181] In some embodiments, the gaseous arsenic compound can be used to remove impurities such as hydrogen after catalytic cracking and condensation.

[0182] The catalyst can effectively promote the cracking of arsine due to its special electronic structure and surface activity. These catalysts form coordination bonds with arsine to reduce the energy barrier of the reaction and increase the reaction rate, thereby obtaining high-purity arsenic, effectively reducing the reaction temperature and increasing the rate of arsine thermal decomposition.

[0183] In some embodiments, the catalyst is one of the oxides corresponding to transition metals / noble metals.

[0184] In some embodiments, the transition metal comprises cobalt, nickel, copper or manganese; and the noble metal comprises gold, silver or platinum.

[0185] In some specific embodiments, the catalyst is copper oxide, silver oxide or nickel oxide. In particular, copper oxide is preferred as it has shown good results in the process of catalytic cracking of arsine to produce high-purity arsenic, mainly due to its unique electronic state regulation ability. 2+ and Cu + Two different chemical electronic states, Cu 2+ It can participate in the reaction as an oxidation source, promoting the dehydrogenation reaction of arsine to produce high-purity arsenic; and Cu + Copper in a reduced state helps to promote the release of elemental arsenic and reduce the formation of by-products. Similarly, the surfaces of silver oxide and nickel oxide have similar electron transfer capabilities, which can promote the adsorption and dehydrogenation of arsine, and ultimately catalyze the cracking of arsine to produce elemental arsenic. In summary, the dynamic regulation of electrons on the surfaces of these metal catalysts makes the reaction have good selectivity and efficiency, thereby significantly improving the yield of arsine converted to high-purity arsenic and ensuring that the final product is high-purity arsenic.

[0186] In some embodiments, catalytic cracking of arsine can be 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, and promoting the decomposition of arsine at a lower temperature, thereby preparing high-purity arsenic.

[0187] In addition, the introduction of the catalyst avoids the common problem of impurity residues in high-temperature pyrolysis, thereby effectively improving the purity and yield of high-purity arsenic. It should be noted that pyrolysis or catalytic cracking refers to the destruction of the gaseous molecular bonds of arsine, achieving the pyrolysis of arsine into gaseous high-purity arsenic, and then condensing it into solid high-purity arsenic through a condenser.

[0188] In some embodiments, the temperature of the catalytic cracking is 120° C. to 250° C.; and the duration of the catalytic cracking is 1 to 2 hours.

[0189] In some embodiments, the condensation temperature is 50-150° C. lower than the catalytic cracking temperature; and the condensation time is 1-2 hours.

[0190] In some specific embodiments, the catalytic cracking temperature is 200° C., the condensing temperature is 100° C., and the catalytic cracking time and the condensing time are both 1 hour. The heating time needs to be controlled. If the heating time is too short, the impurities will not be completely removed. If the heating time is too long, the preparation efficiency of high-purity arsenic will be affected.

[0191] In some embodiments, the gaseous arsenide gas is catalytically cracked under a slightly positive pressure condition, and the pressure of the slightly positive pressure is 0.001-0.02 MPa. By catalytically cracking arsine under a slightly positive pressure condition to prepare high-purity arsenic, the catalytic conversion process can be effectively maintained to prevent the arsine gas from being too high in pressure and quickly escaping to the condensation outlet.

[0192] In some embodiments, in the step of catalytically cracking the gaseous arsenic compound, the arsine flows in a gas stream and is heated along a flow path.

[0193] In some embodiments, the catalytic cracking and condensing steps include pipelines with different diameters and lengths to directional guide the flow of arsine gas and control the pyrolysis rate. Arsine flows in the corresponding pipelines, that is, flows along the corresponding flow paths in the form of gas streams.

[0194] In some embodiments, the tube diameter is 2-6 cm, and the tube length is 8-12 cm. Under the coordination of the tube diameter and the tube length, the gaseous molecular airflow is controlled, and the arsine is thermally decomposed into gaseous high-purity arsenic.

[0195] In some embodiments, the flow rate of the arsine in the form of a gas stream is 1-2 L / min / cm 2 .

[0196] In some embodiments, the catalyst is added in an amount of 0.005% to 0.01% g / L of the arsine gas flow rate.

[0197] In some embodiments, the amount of catalyst added is 5-10% of the mass of the gaseous arsenide. When the gaseous arsenide is added in a gas stream, the amount of the gaseous arsenide added remains unchanged, and the catalyst is added in a manner of 0.005%-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%-0.01% g.

[0198] In some embodiments, the high purity arsenic is packaged in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0199] In some embodiments, the sealing is achieved through a sealed interface. The sealed interface method is a face seal (VCR) joint connected to a ball valve, a VCR connected to a VCR, or a VCR connected to a ferrule; wherein the sealed interface method is not specifically limited, as long as the sealing and reliability of the connection are ensured.

[0200] In some embodiments, in a closed protective gas environment, high-purity arsenic is transferred to a glove box and packaged in electronic-grade packaging bags to ensure that the high-purity arsenic is not contaminated by oxygen and moisture in the outside air during the transfer and packaging process, thereby further reducing the impurity content and ensuring the stability of product quality.

[0201] The above-mentioned method for catalytic cracking of gaseous arsenide is to condense and collect the gaseous arsenide 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; the total impurity content of the high-purity arsenic is <0.1ppm. By strictly controlling the temperature of catalytic cracking and utilizing the catalytic effect of the catalyst, the gaseous arsenide is catalytically cracked into gaseous high-purity arsenic at low temperature, which is converted into solid high-purity arsenic after condensation and collected. The method for catalytic cracking of gaseous arsenide provided by the present invention is simple in process, easy to operate, and the prepared high-purity arsenic product has high purity and yield.

[0202] The present invention also provides a device for catalytic cracking of gaseous arsenide, comprising: The catalytic cracking device comprises a heater with adjustable temperature, a condenser and a collector.

[0203] 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; and the duration of the catalytic cracking is 1 to 2 hours.

[0204] In some embodiments, the temperature of the catalytic cracking is 200° C., and the duration of the catalytic cracking is 1 hour.

[0205] In some embodiments, the heater can be a pyrolysis tower, which can heat within the temperature control range and return to room temperature after the heating stops. The heating temperature control range of the heater is 100°C to 300°C. It is used for catalytic pyrolysis of arsine.

[0206] In some embodiments, gaseous arsenide is introduced into a catalytic cracking device, first heated by a heater in which a catalyst is placed, and the temperature is adjusted to break the arsenic hydrogen bonds due to thermal decomposition, thereby achieving thermal decomposition of arsine into gaseous high-purity arsenic, which is then condensed into solid high-purity arsenic through a condenser.

[0207] The condenser is connected to the heater and is used to condense the arsine pyrolysis products in the pyrolysis gas to form a condensate; the condensation time is 1 to 2 hours.

[0208] The collector is connected to the condensation outlet of the condenser and is used to collect condensate to obtain the high-purity arsenic.

[0209] The recovery device is connected to the gas phase outlet of the condenser and is used for collecting the gas phase.

[0210] In some embodiments, impurities such as hydrogen and oxygen are collected in the recycler.

[0211] In some embodiments, the collector is used to collect the condensate as solid high-purity arsenic.

[0212] In some embodiments, the heater is sealedly connected to the condenser and the collector in sequence.

[0213] Wherein, the collector is located below the condenser.

[0214] In some embodiments, on the same horizontal plane, from left to right, the heater is sealedly connected to the condenser and the collector in sequence, wherein the collector is located below the condenser.

[0215] In some embodiments, the heater is connected to the condenser, the collector and the recovery device in sequence.

[0216] Wherein, the condenser is connected to the heater.

[0217] The collector is located below the condenser.

[0218] In some embodiments, on the same horizontal plane, from left to right, the heater is connected to the condenser, the collector and the recovery device, wherein the connection mode is a sealed connection.

[0219] In some embodiments, the condenser is connected to the heater; the collector is located below the condenser; the recovery device is located above the condenser. The position of the recovery device is not specifically limited, and any position that can achieve the purpose of recovering gas can be used.

[0220] 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; a high-purity arsenic product with a purity of 7N or higher is obtained.

[0221] The device for preparing high-purity arsenic by catalytic cracking of gaseous arsenic provided in the present application has a simple process, is easy to operate, simplifies the preparation process, reduces the difficulty of production, realizes the thermal decomposition of arsine and the removal of impurities, and obtains a high-purity arsenic product with a purity of 7N or higher.

[0222] The pressure in the pyrolysis device of the embodiment and comparative example corresponding to this part is 0.01 MPa. The yield is the actual yield, and the yield = the mass of high-purity arsenic divided by the mass of arsine × 100%.

[0223] For further understanding of the present invention, examples are given below: Among them, Example 1 and Example 2 correspond to the technical solution description of step S1.

[0224] Example 1 1. Microwave drying of arsenic sulfide slag (As2S3) with a moisture content of 60%, and after drying for 1 hour, crushing into 200 mesh powder in a crusher. Use an electronic balance to weigh a certain amount of iron powder and arsenic sulfide slag powder as raw materials, and add them into a dual-temperature roasting furnace according to a molar ratio of iron element to arsenic element of 3:1.

[0225] 2. Set the temperature of the dual temperature zones and then conduct calcination and purification reaction; the calcination temperature is: 650°C in the reaction zone and 450°C in the receiving zone. After keeping warm for 4 hours, both are naturally cooled to room temperature.

[0226] 3. The first purity crude arsenic is obtained by collecting in the receiving area. ICP analysis shows that the main impurity is Sb with a content of 1326 mg / g. Finally, the first purity crude arsenic is obtained with a purity of 2N.

[0227] Specifically, the elemental quantitative analysis results of the first purity crude arsenic are as follows: Figure 1 As shown, according to Figure 1Analysis shows that the Sb content is as high as 1326.2ppm, which is the impurity element with the highest content. Other impurity elements include Si, S, B, etc., with concentrations of 52.3ppm, 4.6ppm, and 1.5ppm respectively. In addition, the oxygen content is as high as 7.4%. The purity of the first purity crude arsenic sample is analyzed, which is 2N grade oxygen-containing crude arsenic. The purity of the first purity crude arsenic is obtained by ICP full element determination of impurity content, excluding oxygen content. The oxygen content is listed separately through the oxygen content analyzer test.

[0228] The element content of the first purity crude arsenic is scanned as follows Figure 2 As shown, the first purity crude arsenic is subjected to a full element content scan, and the purity is analyzed by difference method. Figure 2 The results of elemental quantitative analysis show that Sb is the most important impurity in the first purity crude arsenic, with an impurity content of up to 0.18%. Other important impurities include Ca, Fe, K, Na, Se, etc., which are 0.0019%, 0.0053%, 0.0010%, 0.0038%, and 0.0037%, respectively.

[0229] The XRD phase analysis diagram of the first purity crude arsenic is as follows: Figure 3 As shown, according to Figure 3 It can be observed that the mineral composition of the first purity crude arsenic mainly contains a large amount of arsenic oxide in addition to elemental arsenic.

[0230] Example 2 Compared with Example 1, only the calcination temperatures of the reaction zone and the receiving zone in step 2 are changed: 1. Microwave drying of arsenic sulfide slag (As2S3) with a moisture content of 60%, and after drying for 1 hour, crushing into 200 mesh powder in a crusher. Use an electronic balance to weigh a certain amount of iron powder and arsenic sulfide slag powder as raw materials, and add them into a dual-temperature roasting furnace according to a molar ratio of iron element to arsenic element of 3:1.

[0231] 2. Set the temperature of the dual temperature zones and then conduct the calcination and purification reaction; the calcination temperature of the reaction zone is 700°C and that of the receiving zone is 500°C. After keeping the temperature for 4 hours, both are naturally cooled to room temperature.

[0232] 3. The first purity crude arsenic is obtained by collecting in the receiving area. ICP analysis shows that the main impurity is Sb with a content of 1791 mg / g. Finally, the first purity crude arsenic is obtained with a purity of 2N.

[0233] Example 3 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 fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0234] 2. Evacuate the vacuum container, seal it after the vacuum degree is 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0235] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0236] 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%.

[0237] Example 4 Compared with Example 3, only the dosage of the first reducing agent in step 1 is changed: 1. First, 100 g of the first purity crude arsenic prepared in Example 1, 3 g of carbon powder, and 10 g of copper powder are placed in an inert atmosphere, and fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0238] 2. Evacuate the vacuum container, seal it after the vacuum degree is 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0239] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0240] 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%.

[0241] Example 5 Compared with Example 3, only the dosage of the first reducing agent in step 1 is changed: 1. First, 100 g of the first purity crude arsenic prepared in Example 1, 1 g of carbon powder, and 10 g of copper powder are placed in an inert atmosphere, and fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0242] 2. Evacuate the vacuum container, seal it after the vacuum degree is 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0243] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0244] 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%.

[0245] Example 6 Compared with Example 3, only the temperature of the hot and cold ends in step 2 is changed: 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 fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0246] 2. Evacuate the vacuum container, seal it after the vacuum degree is 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0247] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0248] 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%. The second purity crude arsenic powder is subjected to full element determination, and the results are as follows: Figure 4 As shown, it was found that the antimony content was greatly reduced by more than 89% after vacuum sublimation, and the purity of the crude arsenic after volatilization was increased from 2N to 4N. The low-volatile impurities such as antimony were volatilized from the crude arsenic by the vacuum sublimation of the first vacuum environment in coordination with the first reducing agent and the purifying agent, thereby further improving the purity of the arsenic.

[0249] Example 7 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 arsenic metal mixture into a vacuum container.

[0250] 2. Evacuate the vacuum container containing the arsenic metal mixture, 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.

[0251] 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. The product purity reaches 99.9% and the crystal structure conforms to the standard Zn3As2 card configuration. The phase analysis diagram of the metal arsenide product prepared in this embodiment is as follows: Figure 5 As shown in (a), the crystal structure completely conforms to the standard Zn3As2 card configuration, and no oxidized impurities are analyzed (that is, by comparing the measured XRD peaks with the standard PDF card, comparing the high overlap of the main peaks, secondary peaks, etc.).

[0252] Calculated by mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.09; Zn 67.02; As 31.89. The difference between the saturated vapor pressure and the maximum volatilization rate under vacuum conditions between arsenic and antimony is that antimony is not 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.

[0253] Example 8 Compared with Example 7, only the melting reaction temperature in step 2 was changed: 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 activated carbon powder with a mass of 0.1% of the mass of the second purity crude arsenic, mix them thoroughly with a mixer, and add the arsenic metal mixture into a vacuum container.

[0254] 2. Evacuate the vacuum container containing the arsenic metal mixture, 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 780°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0255] 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.

[0256] 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.

[0257] Example 9 Compared with Example 7, only the melting temperature in the step is changed: 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.

[0258] 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.

[0259] 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.

[0260] 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.

[0261] Example 10 Compared with Example 7, only the melting temperature in the step is changed: 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.

[0262] 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.

[0263] 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).

[0264] 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.

[0265] Embodiment 11 Compared with Example 7, only the ratio of the arsenic active metal material in step 1 is changed: 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] Example 12 Compared with Example 7, only the vacuum conditions in step 2 were changed: 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.

[0270] 2. Evacuate the vacuum container containing the mixture, seal it after the vacuum degree is reduced to 1Pa, 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.

[0271] 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% and the crystal structure conforms to the standard Zn3As2 card configuration.

[0272] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.21; Zn 68.27; As 30.19; Sb 0.33.

[0273] Embodiment 13 Compared with Example 7, only the type of active metal material in step 1 is changed: 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, 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.

[0274] 2. Evacuate the vacuum container containing the mixture to a vacuum degree of 0.001Pa and then seal it. 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 Mg3As2 card configuration.

[0275] 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%.

[0276] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 1.91; Mg 62.90; As 35.00; Sb 0.19.

[0277] Embodiment 14 Compared with Example 7, only the type of the second reducing agent in step 1 is changed: 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.

[0278] 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.

[0279] 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%.

[0280] 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.

[0281] Embodiment 15 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.

[0282] 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.

[0283] 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.

[0284] Example 16 Compared to Example 15, only step 2 is changed; that is, the rate of addition of sulfuric acid is changed: 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 in the last vacuuming, and the temperature of the sulfuric acid in the environment was maintained at 30°C.

[0285] 2. The addition of sulfuric acid is controlled by a liquid inlet device, wherein the addition rate of sulfuric acid is controlled at 100 mL / min, the sulfuric acid is 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 2 L / min. During the reaction, arsine gas is continuously generated and enters the rear-end drying and dehydration 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.

[0286] 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, and the crude arsine gas (i.e., gaseous arsenide) with extremely low moisture content (<0.1%) is produced, and the product quality meets the requirements.

[0287] Embodiment 17 Compared with Example 15, only step 1 is changed; that is, the dosage of the metal arsenide is changed: 1. First, 300 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 in the last vacuuming, and the temperature of the sulfuric acid in the environment was maintained at 30°C.

[0288] 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. 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.

[0289] 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, and finally the crude arsine gas (i.e., gaseous arsenide) with extremely low moisture content (<0.1%) is obtained, and the product quality meets the requirements.

[0290] Embodiment 18 Compared with Example 3, only the type of the first reducing agent in step 1 is changed: 1. First, 100 g of the first purity crude arsenic prepared in Example 1, 5 g of zinc powder, and 10 g of copper powder are placed in an inert atmosphere, and fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0291] 2. Evacuate the vacuum container containing the mixed material, seal it after the vacuum degree is drawn to 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0292] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0293] The purity of the second purity crude arsenic is 99%, and the antimony content is 564.5 mg / kg.

[0294] Comparative Example 1 Compared with Example 3, only the type of the first reducing agent in step 1 is changed: 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, fully mix them with a mixer to obtain a mixed arsenic material, and add the mixed arsenic material into a vacuum container.

[0295] 2. Evacuate the vacuum container containing the mixed material, seal it after the vacuum degree is drawn to 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0296] 3. Take out the purified arsenic block under an inert atmosphere, crush it with a grinding machine and then sieve it. Set the crusher time to 10 minutes and the sieve mesh to 200 meshes to finally obtain an arsenic element powder product that meets the requirements, i.e., second purity crude arsenic.

[0297] 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 dissipated to the cold end, resulting in a significant increase in the antimony content concentration in the purified arsenic powder.

[0298] Comparative Example 2 Compared with Example 3, only the temperature of the hot and cold ends in step 2 is changed: 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, fully mix them with a mixer to obtain a mixed arsenic material, and add the mixed arsenic material into a vacuum container.

[0299] 2. The vacuum container with the mixed material was evacuated to a vacuum degree of 0.001Pa and then sealed. The sealed vacuum container was placed in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature was 450°C, the cold end temperature was 250°C, and the sublimation time was 6 hours. As the volatilization temperature was too low, the arsenic was not completely volatilized.

[0300] Comparative Example 3 Compared with Example 3, only the vacuum degree in step 2 is changed: 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, fully mix them with a mixer to obtain a mixed arsenic material, and add the mixed arsenic material into a vacuum container.

[0301] 2. The vacuum container with the mixed material was evacuated to 100Pa and then sealed. The sealed vacuum container was placed in a vacuum sublimation furnace with multiple temperature zones for sublimation reaction. The hot end temperature was 700°C, the cold end temperature was 500°C, and the sublimation time was 6h. Due to the high vacuum degree, the arsenic was not completely volatilized.

[0302] Comparative Example 4 Compared with Example 3, only the purifying agent is added without the first reducing agent: 1. First, 100 g of the first purity crude arsenic prepared in Example 1 and 10 g of copper powder are placed in an inert atmosphere, and are fully mixed by a mixer to obtain a mixed arsenic material, and the mixed arsenic material is added into a vacuum container.

[0303] 2. Evacuate the vacuum container, seal it after the vacuum degree is 0.001Pa, and 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 6h. After the sublimation reaction is completed, cool it to obtain a purified arsenic block.

[0304] 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, the oxidized impurities are difficult to be reduced to low-valent arsenic that is easier to sublime, so the arsenic purification effect is poor, and most of the oxidized arsenic remaining in the crude arsenic is not reduced.

[0305] Comparative Example 5 Compared with Example 7, only the melting temperature in step 2 was changed: 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 first purity crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0306] 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 700°C, and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0307] 3. The metal arsenide block is taken out under an inert atmosphere, crushed by a ball mill and then sieved. The ball milling time is set to 6 hours and the mesh size is 6. Finally, due to the low melting temperature, the ratio of arsenic and metal does not meet the metal arsenide dosage ratio, and the product crystal structure tends to be a single arsenic card configuration. The phase analysis diagram of the metal arsenide product prepared in this comparative example is as follows: Figure 5 As shown in (b), the crystal structure is mainly a card configuration of single-element As.

[0308] In terms of mass fraction, the chemical composition of the metal arsenide includes (wt%): O 2.00; Zn 3.08; As 94.59; Sb0.33. At this temperature, arsenic has begun to volatilize and densely wraps around the outer surface of the oxygen-containing crude arsenic, affecting the formation of gaseous arsenic. In addition, the reaction activity of zinc is low, and the reaction between arsenic and zinc is hindered, resulting in an imbalance in the arsenic-metal ratio in the subsequent metal arsenide, and the product crystal structure tends to be a card configuration of single arsenic.

[0309] Comparative Example 6 Compared with Example 7, only the reaction time and vacuum conditions in step 2 were changed: 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.

[0310] 2. The vacuum container with the mixture is sealed without vacuuming (i.e., normal pressure), and the sealed vacuum container is placed in a high-temperature furnace for melting reaction. The reaction temperature is set at 800°C and the reaction time is 2 hours. The melting reaction ends. Because the reaction time is too short, the final product is not completely reacted and presents a separate two-phase structure of elemental arsenic and zinc. Therefore, the metal arsenide block after the reaction cannot be obtained.

[0311] Comparative Example 7 Compared to Example 7, only the reaction time in step 2 was changed: 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.

[0312] 2. The vacuum container with the mixture was evacuated to 0.001Pa and sealed, and the sealed vacuum container was placed in a high-temperature furnace for melting reaction. The reaction temperature was set to 800°C and the reaction time was 4h. At the end of the melting reaction, an obvious two-phase structure could be seen due to the short reaction time. The final product of the melting reaction was not completely reacted due to the short reaction time, presenting a separate two-phase structure of elemental arsenic and zinc. Therefore, the metal arsenide block after the reaction was not obtained.

[0313] Comparative Example 8 Compared with Example 7, only the vacuum degree in step 2 is changed: 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. The vacuum container with the mixed material is evacuated to a vacuum degree of 100 Pa and then sealed. The sealed vacuum container is placed in a high-temperature furnace for melting reaction. The reaction temperature is set to 800°C and the reaction time is 6 hours. After the melting reaction is completed, the metal arsenide block is obtained by cooling. Due to the high vacuum degree of the reaction conditions, the Zn3As2 phase in the product is partially oxidized, and arsenic oxide appears in the product, which has a certain adverse effect on the subsequent use of the product for high-purity arsenic preparation and gas production reaction.

[0315] 3. The metal arsenide block is taken out under an inert atmosphere, crushed by a ball mill and then sieved. The ball milling time is set to 6 hours and the mesh size is 6. Finally, metal arsenide particles are obtained. The product purity is 99%, the crystal structure conforms to the standard Zn3As2 card configuration, and the oxygen content is 2.78%.

[0316] Comparative Example 9 Compared with Example 7, only the vacuum degree in step 2 is changed: 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.

[0317] 2. The vacuum container with the mixture is sealed without evacuating the vacuum (i.e., at normal pressure), and the sealed vacuum container is placed in a high-temperature furnace for melting reaction. The reaction temperature is set at 800°C and the reaction time is 6 hours. After the melting reaction is completed, the metal arsenide block is obtained by cooling. Since no vacuum environment is set, the Zn3As2 phase in the product is oxidized in large quantities, and a large amount of arsenic oxide appears in the product, which has a very adverse effect on the subsequent use of the product for high-purity arsenic preparation and gas production reaction.

[0318] 3. The metal arsenide block was taken out under an inert atmosphere, crushed by a ball mill and then sieved. The ball milling time was set to 6 hours and the mesh size was 6. The final metal arsenide / arsenic oxide mixed particles had an oxygen content of 20.36%, which did not meet the requirements.

[0319] Comparative Example 10 Compared with Example 7, only the ratio of the arsenic active metal material in step 1 is changed: 1. First, 100 g of the second purity crude arsenic obtained in Example 3 and 100 g of zinc powder are placed in an inert atmosphere, and activated carbon powder with a mass of 0.1% of the second purity crude arsenic is added, and the mixture is fully mixed by a mixer, and the mixture is added into a vacuum container.

[0320] 2. Evacuate the vacuum container with the mixed material to a vacuum degree of 0.001 Pa and then seal it. 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 6 hours. After the melting reaction is completed, cool it to obtain a metal arsenide block. Due to insufficient zinc content in the raw material, the phase structure of the product contains some ZnAs2 in addition to Zn3As2, which has a certain adverse effect on the subsequent preparation of high-purity arsenic gas production process, and reduces the gas production.

[0321] 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 to finally obtain a mixed particle product of Zn3As2 and ZnAs2.

[0322] Comparative Example 11 Compared with Example 15, only the vacuum conditions in step 1 were changed: 1. First, 500 g of the metal arsenide prepared in Example 7 is placed in a reaction device, and the reaction device is under normal pressure and air atmosphere.

[0323] 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, 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 rear-end drying and dehydration device. The reaction time is 60 minutes. 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.

[0324] 3. The temperature of the drying and dehydration device was set at 80°C, but since vacuum replacement was not performed, the moisture content of the crude arsine gas (>1.3%) did not meet the requirements.

[0325] Comparative Example 12 Compared to Example 15, only step 2 is changed; that is, the rate of addition of sulfuric acid is changed: 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 by the last vacuuming.

[0326] 2. The addition of sulfuric acid is controlled by a liquid inlet device, wherein the addition rate of sulfuric acid is controlled at 250 mL / min. The sulfuric acid is present 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 rear-end drying and dehydration 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.

[0327] 3. The temperature of the drying and dehydration device is set at 80°C, so the arsine gas generation rate is too fast, and impurities such as moisture cannot be dried and removed in the drying and dehydration device. The moisture content of the crude arsine gas finally obtained (>0.6%) does not meet the requirements.

[0328] Comparative Example 13 Compared with Example 15, only step 3 is changed; that is, the drying and water removal device is not started: 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 by the last vacuuming.

[0329] 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 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 rear-end drying and dehydration device. The reaction time is 60 min. 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.

[0330] 3. The drying and dehydration device is not turned on, so that the impurities such as moisture in the arsine gas cannot be dried out and removed in the drying and dehydration device, and the moisture content of the crude arsine gas (>2.1%) obtained finally does not meet the requirements.

[0331] Comparative Example 14 Compared with Comparative Example 5, only the vacuum conditions in step 2 were changed: 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.

[0332] 2. The vacuum container with the mixture is sealed without evacuating the vacuum (i.e., normal pressure), and the sealed vacuum container is placed in a high-temperature furnace for melting reaction. The reaction temperature is set to 700°C and the reaction time is 6 hours. Because no vacuum environment is set, the melting and boiling points of the reactants are relatively high under this condition. The final product of the melting reaction is not completely reacted due to the low temperature, presenting a separate two-phase structure of elemental arsenic and zinc. Therefore, the metal arsenide block after the reaction cannot be obtained.

[0333] Analysis example 1 The parameters of the metal arsenide used in Examples 15 to 17 and Comparative Examples 11 to 13 are analyzed, wherein the total impurity content of the metal arsenide is <0.1%, the purity is 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%.

[0334] Analysis example 2 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.

[0335] Embodiment 19 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.

[0336] 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.

[0337] 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.

[0338] Embodiment 20 Among them, compared with Example 19, Example 20 changed the top and bottom temperatures of the light-removal tower and the heavy-removal tower.

[0339] 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.

[0340] 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.

[0341] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0342] Embodiment 21 Compared with Example 19, Example 21 changes the first pressure.

[0343] 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 0.4 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.

[0344] 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.

[0345] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0346] Embodiment 22 Compared with Example 19, Example 22 changes the first pressure.

[0347] The gaseous arsenide (mainly arsine) prepared in Example 15 is fed into a low-pressure condensation distillation device, the first pressure is adjusted to 0.2 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 first purity arsine. This process effectively removes high boiling point and low boiling point impurities in arsine.

[0348] 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.

[0349] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0350] Embodiment 23 In which, compared with Example 19, Example 23 changes the adsorbent type.

[0351] 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.

[0352] The first purity arsine is fed into an adsorption device filled with pore-adjusting activated carbon at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The impurities with small molecular kinetic diameter are effectively removed, and trace impurities that have not been removed are activated.

[0353] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0354] Embodiment 24 Among them, compared with Example 19, Example 24 changes the temperature of the heating mechanism.

[0355] 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.

[0356] 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.

[0357] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 100° 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.

[0358] Embodiment 25 In which, compared with Example 19, Example 25 changes the adsorbent type.

[0359] 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.

[0360] The first purity arsine is fed into an adsorption device filled with 4A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The impurities with small molecular kinetic diameter are effectively removed, and trace impurities that have not been removed are activated.

[0361] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0362] Embodiment 26 In which, compared with Example 19, Example 26 changes the adsorbent type.

[0363] 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.

[0364] The first purity arsine is fed into an adsorption device filled with 5A 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.

[0365] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0366] Embodiment 27 In which, compared with Example 19, Example 27 changes the temperature of the adsorption device.

[0367] 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.

[0368] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 50°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.

[0369] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism 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.

[0370] Comparative Example 15 Among them, compared with Example 19, the temperature of the heating mechanism was changed in Comparative Example 15.

[0371] 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.

[0372] 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.

[0373] The second purity arsine is introduced into a heating mechanism at a temperature of 50° C. for 2 hours to obtain an arsine product with a purity of 4 N. Since the temperature of the heating mechanism is too low, the antimonane impurities are not completely removed, resulting in a decrease in product purity.

[0374] Comparative Example 16 Among them, compared with Example 19, the temperature of the adsorption device was changed in Comparative Example 16.

[0375] 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.

[0376] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at room temperature (25° C.), and an adsorption operation is performed for 2 hours to obtain second purity arsine.

[0377] The second purity arsine is introduced into a heating mechanism with a temperature of 150°C and a heating time of 2 hours to obtain an arsine product. Since the temperature of the adsorption device is relatively low, trace impurities are not fully activated, and the efficiency of the heating mechanism in pyrolyzing unactivated trace impurities is reduced, and the purity of the final product is 6N.

[0378] in, Figure 8 This is a schematic diagram of the operation flow of Examples 19 to 27 of the present application, Fig. 9 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 arsenic compounds in Examples 19-27 and Comparative Examples 15-16.

[0379] Table 3 Boiling points of arsine and main impurities in arsine Table 4 Relevant parameters for gaseous arsenide purification in Examples 19-27 and Comparative Examples 15-16 Combining the data in Table 3 and Table 4, it can be seen that by regulating the light removal tower top temperature, the first pressure, the adsorbent type, the temperature of the adsorption device, and the temperature of the heating mechanism, and then controlling the light removal tower bottom temperature and the heavy removal tower top and bottom temperatures within a suitable range, all within the first temperature, the gaseous arsenide is purified to obtain electronic grade gaseous arsenide with a purity of about 7N. These key factors have a significant impact on the purity of arsine.

[0380] Wherein, the first temperature is -80°C~-10°C; the first pressure is 0.1MPa~0.6MPa.

[0381] Examples 19 to 22, through different light removal tower top temperatures and first pressure optimization, reflect the effectiveness of reaction conditions and device coordination for impurity removal. Among them, compared with Example 19, Example 20 has a lower light removal tower top temperature, but the antimony removal rate is not much different; compared with Example 19, Example 21 has a reduced first pressure, and the corresponding antimony removal rate is similar, while the silicon removal rate and sulfur removal rate are slightly increased, all indicating that controlling the appropriate light removal tower top temperature and first pressure can effectively remove low-boiling impurities methane, ethane or silane and most of the high-boiling impurities antimonane at low temperature and low pressure.

[0382] Compared with Example 19, Examples 23 and Examples 25-26 change the adsorbent type. From the corresponding results in Table 4, the top temperature of the light removal tower, the first pressure, and the temperature of the heating mechanism are adjusted to a suitable range. The adsorbent types are 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve, which can remove the impurity hydrogen sulfide and dry it to obtain the second purity arsine. At the same time, the temperature of the adsorption device is the second temperature of 50-80°C, and other thermodynamically unstable impurities can be activated simultaneously.

[0383] Compared with Example 19, although the temperature of the heating mechanism in Example 24 is reduced, the corresponding antimony removal rate is not much different, and the removal rates of sulfur and silicon are increased, which further illustrates that by regulating the temperature of the heating mechanism, the thermodynamically unstable impurities remaining in the distillation device and the adsorption device, such as a small amount of antimonane, oxygen, carbon dioxide, nitrogen or germane, can be effectively removed to obtain an electronic grade gaseous arsenide product with a purity of 7N.

[0384] The results of Comparative Examples 15 and 16 show that when the optimal reaction conditions are not controlled, the impurity content in arsine increases significantly. For example, in Comparative Example 15, the temperature of the heating mechanism is too low to remove thermodynamically unstable impurities; in Comparative Example 16, the temperature of the adsorption device is only room temperature (25°C), so the trace impurities are not fully activated, resulting in a decrease in the efficiency of the pyrolysis device and a final product purity of 6N.

[0385] In summary, in Example 19, the first pressure is regulated to be 0.5MPa, the top temperature of the light tower is -66~-62°C, the bottom temperature is -40~-25°C, the top temperature of the heavy tower is -61~-52°C, the bottom temperature is -30~-15°C, maintained for 2 hours, the adsorbent uses 3A molecular sieve, the second temperature of MPa is 80°C and the adsorption operation is performed for 2 hours, the temperature of the heating mechanism is 150°C, and the heating time of the heating mechanism is 2 hours, and the relatively optimal electronic-grade gaseous arsenide product can be obtained, wherein the impurity antimony removal rate is 99.994%, the silicon removal rate is 99.2%, the sulfur removal rate is 87.2%, and the purity of the electronic-grade gaseous arsenide is 7N, showing an excellent de-impurity effect. This provides a strong basis for further optimizing the preparation process of electronic-grade arsine.

[0386] Embodiment 28 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0387] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0388] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 286.2 g of high-purity arsenic with a yield of 57.2%.

[0389] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0390] Embodiment 29 In which, compared with Example 28, Example 29 changes the temperature of catalytic cracking.

[0391] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 150° C., and the duration of catalytic cracking was 1 hour.

[0392] The flow rate of the gaseous arsenic compound in the pyrolysis device (i.e., the flow rate of the gaseous arsenic compound in the form of a gas stream, the same below) is 1 L / min / cm 2 .

[0393] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 253.7 g of high-purity arsenic with a yield of 50.7%.

[0394] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0395] Embodiment 30 In which, compared with Example 28, Example 30 changes the temperature of catalytic cracking.

[0396] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 250° C., and the duration of catalytic cracking was 1 hour.

[0397] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0398] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 289.2 g of high-purity arsenic with a yield of 57.8%.

[0399] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0400] Embodiment 31 In which, compared with Example 28, Example 31 changes the temperature of catalytic cracking.

[0401] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of the arsine, was added as a catalyst. The temperature for catalytic cracking was 300° C., and the duration of catalytic cracking was 1 hour.

[0402] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0403] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 291.7 g of high-purity arsenic with a yield of 58.3%.

[0404] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0405] Embodiment 32 Compared with Example 28, Example 32 changes the flow rate of the airflow.

[0406] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0407] The air flow rate of the pyrolysis device is 2L / min / cm 2 .

[0408] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 196.5 g of high-purity arsenic with a yield of 39.3%.

[0409] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0410] Embodiment 33 Among them, compared with Example 28, Example 33 changes the catalyst type.

[0411] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and silver oxide, which was 5% by weight of the arsine, was added as a catalyst. The temperature of catalytic cracking was set to 200° C., and the duration of catalytic cracking was 1 hour.

[0412] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0413] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 81.5 g of high-purity arsenic with a yield of 16.3%.

[0414] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0415] Embodiment 34 In which, compared with Example 28, Example 34 changes the catalyst type.

[0416] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and nickel oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature of catalytic cracking was set to 200° C., and the duration of catalytic cracking was 1 hour.

[0417] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0418] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 67.7 g of high-purity arsenic with a yield of 13.5%.

[0419] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0420] Embodiment 35 In which, compared with Example 1, Example 35 changes the mass of the catalyst.

[0421] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 10% by weight of the arsine, was added as a catalyst. The temperature for catalytic cracking was 200° C., and the catalytic cracking time was 1 hour.

[0422] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0423] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 292.7 g of high-purity arsenic was obtained with a yield of 58.5%.

[0424] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0425] Comparative Example 17 Among them, compared with Example 28, the temperature of catalytic cracking was changed in Comparative Example 17.

[0426] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 80° C., and the duration of catalytic cracking was 1 hour.

[0427] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0428] The arsine after catalytic cracking is sent to a condensation device at a condensation temperature of 30°C and a condensation time of 1 hour to obtain an arsenic product.

[0429] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0430] However, due to the low temperature of catalytic cracking, only 13.7 g of final arsenic product was obtained, with a yield of 2.7% and a purity of only 5N.

[0431] Comparative Example 18 Among them, compared with Example 28, the step of sending the material into the pyrolysis device is omitted in Comparative Example 18.

[0432] 500 g of electronic grade arsine prepared in Example 19 was directly fed into a condensation device at a condensation temperature of 100° C. for 1 hour to obtain an arsenic product.

[0433] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0434] Due to the lack of a pyrolysis device, arsine was not fully decomposed, and only 1.2 g of arsenic product was obtained in the end, with a yield of 0.24%. The purity only reached 4N level, which could not meet the application requirements of high-purity arsenic.

[0435] Comparative Example 19 Compared with Example 28, the enclosed atmosphere is omitted in Comparative Example 19.

[0436] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature for catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0437] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0438] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 279.2 g of high-purity arsenic with a yield of 55.8%.

[0439] The arsenic product was directly transferred into a glove box and then packaged in an electronic grade packaging bag.

[0440] Since the product was not directly transferred to the glove box in a closed atmosphere, it was exposed to the external environment and oxygen during the transfer process, causing the product purity to drop to 5N, the oxygen content >1.5%, and the product quality did not meet the requirements.

[0441] Comparative Example 20 Among them, compared with Example 28, the catalyst type was changed in Comparative Example 20.

[0442] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device, and metal palladium, which was 5% by weight of the arsine, was added as a catalyst. The temperature for catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0443] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0444] The arsine after catalytic cracking was sent to a condensation device at a condensation temperature of 100°C and a condensation time of 1 hour to obtain 23.2 g of high-purity arsenic with a yield of 4.6%.

[0445] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0446] Due to the poor catalytic pyrolysis effect of the added catalyst, the catalytic pyrolysis of the gaseous arsenic compound is incomplete, and only a very small amount of 5N grade arsenic product is obtained.

[0447] Comparative Example 21 Among them, compared with Example 28, the catalyst is omitted in Comparative Example 21.

[0448] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device without adding a catalyst. The cracking temperature was 200° C. and the cracking time was 1 hour.

[0449] The air flow rate of the pyrolysis device is 1L / min / cm2 .

[0450] The cracked arsine was sent to a condensation device at a condensation temperature of 100° C. for 1 hour to obtain 13.9 g of arsenic product with a yield of 2.9%.

[0451] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0452] Since no catalyst was added, the thermal decomposition of the gaseous arsenic compound was incomplete, and only a very small amount of 5N grade arsenic product was obtained.

[0453] Comparative Example 22 Among them, compared with Example 28, in Comparative Example 22, the temperature of catalytic cracking was changed and the catalyst was omitted.

[0454] 500 g of electronic grade arsine prepared in Example 19 was fed into a pyrolysis device without adding a catalyst. The cracking temperature was 500° C. and the cracking time was 1 hour.

[0455] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0456] The cracked arsine was sent to a condensation device at a condensation temperature of 400°C and a condensation time of 1 hour to obtain 238.5 g of arsenic product with a yield of 47.7%.

[0457] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0458] Since no catalyst is added and the cracking temperature is relatively high, although the thermal decomposition of arsine can be promoted, it is difficult to simultaneously treat other thermal impurities that are relatively stable at high temperatures, such as hydrogen sulfide, and ultimately only a small amount of 6N grade arsenic product is obtained.

[0459] in, Fig.10 Schematic diagram of the operation flow of Examples 28 to 35 of the present application. Table 5 is the corresponding data of the industry-related standards for high-purity arsenic products; Table 6 is the relevant parameter analysis of the high-purity arsenic prepared in Examples 28 to 35 and the arsenic products prepared in Comparative Examples 17 to 22.

[0460] Table 5 Corresponding data of relevant industry standards for high-purity arsenic products Table 6 Analysis of relevant parameters of high purity arsenic prepared in Examples 28 to 35 and arsenic products prepared in Comparative Examples 17 to 22 As shown in Table 5 and Table 6, it can be seen from the results of Examples 28 to 35 that the precise control of the temperature of catalytic cracking has a significant effect on the purity of high-purity arsenic. In Example 28, at a catalytic cracking temperature of 200°C, the catalytic cracking of arsine was successfully achieved through a reasonable heating time to form gaseous high-purity arsenic, which was converted into solid high-purity arsenic through a condensing device. In particular, in Example 29, although the temperature of catalytic cracking was reduced to 150°C, the purity of the high-purity arsenic product was still maintained, further proving the effectiveness of adding a suitable catalyst and fully pyrolyzing arsine at an appropriate catalytic cracking temperature, and the purity of the arsine product was >7N. In addition, the catalyst type has a significant effect on the yield of high-purity arsenic prepared by arsine catalysis. By comparing Examples 28, 33, and 34, it was found that when the catalyst was copper oxide, the highest high-purity arsenic yield was shown at a catalytic cracking temperature of 200°C, with a yield of 57.2%, which was significantly improved compared to the yield of high-purity arsenic catalyzed by the other two metal oxides, indicating that the selection of catalyst type is crucial. Compared with Example 28, in Example 35, the mass of the catalyst is increased, so that the yield of high-purity arsenic is 58.5%, which shows that adding an appropriate mass of catalyst, combined with factors such as the catalytic cracking temperature and catalyst type, can improve the yield of high-purity arsenic.

[0461] The results of Comparative Examples 17 to 19 show that when the optimal catalytic pyrolysis temperature is not controlled, the purity of the arsenic product decreases significantly. In Comparative Example 17, the temperature of catalytic cracking is 80°C, but due to the low temperature, the pyrolysis of the gaseous arsenic is not sufficient, and the final product is only 5N grade purity. Comparative Example 20 uses metal palladium as a catalyst, but the catalytic effect is poor, and the sufficient pyrolysis of arsine and the effective removal of impurities cannot be achieved, which once again illustrates the importance of catalyst type selection for the cracking of arsine into high-purity arsenic.

[0462] The results of Comparative Examples 21 and 22 show that without adding a catalyst, the pyrolysis rate is slow, resulting in incomplete decomposition of arsine, ineffective removal of impurities, and low purity of the final product. Especially under the experimental condition of 200°C without adding a catalyst, the pyrolysis reaction is difficult to occur. Even if the temperature of the catalytic pyrolysis is increased to 500°C, the purity of the product decreases significantly, showing the importance of the selection of catalyst type and the temperature of catalytic pyrolysis in the process of pyrolysis of gaseous arsenic to high-purity arsenic. Based on the above embodiments, it can be seen that in Example 28, the temperature of catalytic cracking is 200°C, the temperature of condensation is 100°C, and the flow rate of the airflow of the pyrolysis device is 1L / min / cm 2 , it is possible to obtain high-purity arsenic products with a total impurity content of <0.1ppm and a high-purity arsenic purity of >7N. This provides a strong basis for further optimizing the preparation process of high-purity arsenic, and also emphasizes the importance of proper temperature control and its removal of impurities during the pyrolysis process.

[0463] In summary, the above technical solutions of the present invention are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. All equivalent structural changes made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or directly / indirectly applied in other related technical fields, are 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 the first purity crude arsenic, the first reducing agent and the purifying agent, and sublimating them in a high vacuum environment to obtain the second purity crude arsenic; 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 at the hot end of a closed high vacuum environment for sublimation, and condensate at the cold end of the high vacuum environment is collected to obtain second purity crude arsenic, wherein the high vacuum environment is a first vacuum environment, and the vacuum pressure of the first vacuum environment is not greater than 1Pa.

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: The first reducing agent includes one or more of zinc powder, iron powder, magnesium powder, and carbon powder; and / or; The purifying agent includes one or more of copper powder, cadmium powder, lead powder and sulfuric acid.

7. 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.

8. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 7, 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.

9. 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.

10. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 9, 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.

11. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 9, 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.

12. 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.

13. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 12, 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.

14. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 12, 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.

15. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 14, 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.

16. 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.

17. The method for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 16, 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.

18. A device for extracting high-purity arsenic from arsenic-containing hazardous waste, used for implementing the method for extracting high-purity arsenic from arsenic-containing hazardous waste as claimed in any one of claims 1 to 17, 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.

19. The device for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 18, 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.

20. The device for extracting high-purity arsenic from arsenic-containing hazardous waste according to claim 18, 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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