Method for preparing gaseous arsenide from metal arsenide

Abstract

The present invention provides a method for preparing gaseous arsenide from metal arsenide, comprising the steps of: S1, mixing crude arsenic with a first reducing agent to obtain a mixed arsenic material; placing the mixed arsenic material at the hot end of a closed first vacuum environment for sublimation, collecting condensate at the cold end of the first vacuum environment to obtain elemental arsenic; mixing elemental arsenic with an active metal material to obtain an arsenic metal mixture; placing the arsenic metal mixture in a second vacuum environment for melting reaction to obtain metal arsenide; S2, mixing the metal arsenide with sulfuric acid in a third vacuum environment, and maintaining the temperature of sulfuric acid in the environment at 20-40°C, and obtaining gaseous arsenide through a gas production reaction. The present invention utilizes a triple vacuum environment to achieve the preparation of high-purity gaseous arsenide, and can efficiently achieve industrial production.

Description

Technical Field

[0001] The invention belongs to the field of electronic special gas preparation, and in particular relates to a method for preparing gaseous arsenide from metal arsenide. Background Art

[0002] Arsine (AsH3) is an efficient doping source as an electron gas. It is used to adjust the conductivity of semiconductor materials in the gas phase doping process, especially in the preparation of semiconductor materials such as gallium arsenide (GaAs) and indium arsenide (InAs). In addition, arsenine is also widely used in the manufacture of solar cells, infrared optical materials and organic optoelectronic devices. However, the existing arsenic preparation process faces many challenges, especially in the industrial production process.

[0003] The traditional method for preparing arsine usually uses a metal arsenide (such as zinc arsenide) to react with sulfuric acid to generate arsine gas; although this method has been widely studied and used, its reaction efficiency is low, there is a slow reaction rate, and the side reactions are serious, resulting in poor purity of the product. During the reaction process, moisture and oxygen are often introduced, which not only contaminates the generated arsine, but also makes the subsequent purification steps more complicated and difficult. In addition, due to the existence of side reactions, the energy efficiency in the preparation process is low and the reaction process is difficult to control, so it is difficult to meet the requirements of large-scale industrial production. The dynamic optimization of the reaction system is often ignored in traditional processes. The changes in temperature, pressure and airflow during the reaction process have a direct impact on the generation and purity of arsine; especially at lower temperatures, the reaction rate is often limited, resulting in low and unstable yields of arsine. Therefore, the existing process has significant bottlenecks in practical applications, which limits the further development of arsine in high-purity applications.

[0004] Based on this, it is necessary to provide a method for preparing gaseous arsenide from metal arsenide to alleviate or solve the above problems. Summary of the invention

[0005] In order to solve the technical problems of slow reaction rate and many side reactions in the process of producing arsine in the above-mentioned common technology, the present invention provides a method for preparing gaseous arsenide from metal arsenide, comprising the steps of:

[0006] S1, crude arsenic, a first reducing agent, and a purifying agent are mixed to obtain a mixed arsenic material; then the mixed arsenic material is placed at the hot end of a closed first vacuum environment for sublimation, and condensates at the cold end of the first vacuum environment are collected to obtain elemental arsenic; the elemental arsenic is mixed with an active metal material to obtain an arsenic metal mixture; then the arsenic metal mixture is placed in a second vacuum environment for melting reaction to obtain metal arsenide; the vacuum pressure of the first vacuum environment is not greater than 1Pa, the temperature of the hot end of the first vacuum environment 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 melting reaction in the second vacuum environment is not less than 750°C;

[0007] S2, the metal arsenide is mixed with sulfuric acid in a third vacuum environment, and the temperature of the sulfuric acid in the environment is maintained at 20-40° C., and gaseous arsenide is obtained through a gas production reaction; wherein the sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 5-20%.

[0008] Furthermore, the vacuum degree of the third vacuum environment is 1-100 Pa;

[0009] The formation of the third vacuum environment includes the following steps: S21, evacuating the device for the gas production reaction, and then introducing an inert gas into the device to normal pressure; S22, repeating step S21 at least twice; S23, evacuating the device at normal pressure to 1~100Pa to obtain the third vacuum environment.

[0010] Furthermore, in the third vacuum environment, in the reaction solution formed by mixing the metal arsenide with the sulfuric acid, the concentration of the metal arsenide is 0.1-0.5 mol / L.

[0011] Furthermore, the gaseous arsenide includes arsine; the step S2 further includes: performing a dehydration treatment on the gaseous arsenide; the dehydration treatment includes: passing the arsine into a drying dehydration device, wherein the temperature of the drying dehydration device is set to 0-100°C.

[0012] Furthermore, 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 in by the negative pressure device to maintain the vacuum degree of the third vacuum environment.

[0013] Furthermore, during the gas production reaction, the addition rate of the sulfuric acid solution is 50-200 mL / min; and the generation rate of the gaseous arsenide is 1-3 L / min.

[0014] Furthermore, the vacuum degree in the first vacuum environment is 0.001~0.1Pa; the vacuum degree in the second vacuum environment is 0.001~1Pa.

[0015] Furthermore, the first reducing agent includes one or more of zinc powder, iron powder, and carbon powder, and the amount of the first reducing agent added is 1-5% of the mass of the crude arsenic; the purifying agent includes one or more of copper powder, cadmium powder, lead powder, and sulfuric acid, and the amount of the purifying agent added is 2-10% of the mass of the crude arsenic.

[0016] Furthermore, a second reducing agent is added to the melting reaction, wherein the second reducing agent includes one or more of activated carbon, carbon black, and graphite powder, and the amount of the second reducing agent added is 0.1-0.5% of the mass of the elemental arsenic.

[0017] Furthermore, the mass ratio of the elemental arsenic to the active metal material is 1:1.3 to 1:1.8.

[0018] Compared with the prior art, the present invention has at least the following advantages:

[0019] The present invention provides a method for preparing gaseous arsenide from metal arsenide, and realizes the preparation of arsine by using a triple vacuum environment:

[0020] The first vacuum environment lowers the sublimation temperature of arsenic, and utilizes the difference in saturated vapor pressure, volatilization rate and boiling point between arsenic and the main impurity antimony at low sublimation temperature to separate the two, effectively alleviating the difficulty of impurity separation during the sublimation of crude arsenic and obtaining high-purity elemental arsenic.

[0021] The second vacuum environment avoids the oxidation and hydrolysis problems of crude arsenic during the preparation process, significantly improves the chemical purity and crystal quality of metal arsenide, reduces the formation of arsenic oxide with higher saturated vapor pressure and faster volatilization rate, enhances the arsenic-zinc reaction trend and maintains the arsenic-zinc dosage in the reaction system, and produces Zn3As2 with uniform purity and composition.

[0022] The third vacuum environment reduces the concentration of water and oxygen in the gas-producing reaction system. Combined with the improvement in the purity of the aforementioned metal arsenides and the uniformity of their composition, the high-purity alloy has a more uniform crystal structure and a cleaner surface, and the selectivity and rate of the main reaction (i.e., the reaction of metal arsenides with sulfuric acid to form arsine) are significantly optimized.

[0023] Specifically, the core idea of ​​the present invention is to use three-stage vacuum means to work together and maintain a negative pressure environment at the rear end during the reaction process to promote the efficient production of arsine. The generation process of arsine is synergistically optimized by three-stage vacuum environments, and the reaction efficiency and the purity of arsine are significantly improved by accurately controlling the vacuum environment in the reaction system, especially the negative pressure maintenance in the last reaction stage. While maintaining the negative pressure, the airflow and temperature control of the entire reaction system are more precise, further reducing the possible introduction of impurities and reducing the impact of changes in the external environment on the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 This is a diagram showing the elemental quantitative analysis results of crude arsenic in Example 1 of the present invention;

[0026] Figure 2 This is a graph showing the determination of all element contents of crude arsenic in Example 1 of the present invention;

[0027] Figure 3 is the XRD phase analysis diagram of crude arsenic in Example 1 of the present invention;

[0028] Figure 4 This is a graph showing the determination of the total element content of the purified arsenic obtained in Example 4 of the present invention;

[0029] 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 5 of the present invention, Figure 5 (b) is a phase analysis diagram of the metal arsenide product obtained in Comparative Example 5 of the present invention, Figure 5 (c) is a phase analysis diagram of the metal arsenide product obtained in Example 7 of the present invention, Figure 5 (d) is a phase analysis diagram of the metal arsenide product obtained in Example 8 of the present invention;

[0030] Figure 6 Schematic diagram of the liquid inlet device (metering pump + pneumatic ball valve) in Examples 13 to 15 of the present invention and Comparative Examples 11 to 13, wherein 1 is a first pneumatic ball valve, 2 is a metering pump, and 3 is a second pneumatic ball valve;

[0031] Figure 7It is a schematic diagram of a flow chart in an embodiment of the present invention. DETAILED DESCRIPTION

[0032] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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.

[0033] 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.

[0034] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0035] The present invention provides a method for preparing gaseous arsenide from metal arsenide, such as Figure 7 As shown, the steps include:

[0036] S1, crude arsenic, a first reducing agent, and a purifying agent are mixed and prepared to obtain a mixed arsenic material. The mixed arsenic material is placed in a sealed first vacuum environment, the first vacuum environment includes a hot end and a cold end, the mixed arsenic material is sublimated at the hot end and condensed at the cold end, and the condensate at the cold end is collected to obtain elemental arsenic; the elemental arsenic is mixed and prepared with an active metal material to obtain an arsenic metal mixed material. The arsenic metal mixed material is placed in a second vacuum environment for melting reaction to obtain a metal arsenide.

[0037] Crude arsenic is an arsenic product prepared from arsenic oxide through a carbon reduction process. It has a high impurity content and low economic value. It is usually derived from by-products in non-ferrous metal smelting processes, such as lead and zinc smelting, copper smelting, etc. These smelting processes will produce a large amount of arsenic-containing waste slag.

[0038] In some embodiments of the present invention, the particle size of the crude arsenic can be 0.5~3cm, and the purity of the crude arsenic can be 1N~3N. For example, the purity of the crude arsenic can be 1N~2N; for another example, the purity of the crude arsenic can be 2N; it should be noted that 2N-grade crude arsenic is an arsenic element with an impurity content ≤1% and >0.1%.

[0039] The crude arsenic is subjected to elemental quantitative analysis. The Sb content in the crude arsenic can reach 1~1500ppm, for example, the antimony content in the crude arsenic can be 500~1500ppm; for example, the antimony content in the crude arsenic can be 1000~1500ppm, antimony is the impurity element with the highest content in the crude arsenic, and other impurity elements include Si, S, and B, and the contents can be 40~60ppm, 4~5ppm, and 1~1.5ppm, respectively; the impurities in the crude arsenic can specifically include Sb and S, and the contents are described above; the oxygen content of the crude arsenic is >5% or ≤5%; further, the oxygen content in the crude arsenic can be 5~10%.

[0040] In the present invention, the vacuum pressure of the first vacuum environment may be no greater than 1 Pa; in some embodiments, the vacuum pressure in the first vacuum environment may be 0.001-0.1 Pa, which is a vacuum environment. It should be noted that the vacuum pressure in the present invention is equivalent to the vacuum degree, that is, it expresses the specific apparent pressure value of the gas in the vacuum environment.

[0041] The first vacuum environment has the following functions:

[0042] The main impurity of 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. The present invention adopts vacuum technology to control the vacuum degree in the vacuum environment to 0.001~0.1Pa, and uses the difference between the saturated vapor pressure, volatilization rate and boiling point between arsenic and the main impurity antimony to achieve separation of the two, effectively alleviating the problem of difficult impurity separation during the sublimation of crude arsenic, thereby obtaining high-purity elemental arsenic. The hot end temperature is set in coordination. At this temperature, the volatilization rate of arsenic is significantly higher than that of antimony, so that arsenic can be sublimated to the cold end first, further improving the purity of elemental arsenic.

[0043] The calculation formula for the saturated vapor pressure of each metal at room temperature is:

[0044] log 10 P = A T -1 + Blog 10 T + C T + D

[0045] According to the above formula, the saturated vapor pressure of each metal is calculated as:

[0046]

[0047] In addition, the vacuum environment provides a preparation condition with almost no interference from gas molecules to adapt to the high activity characteristics of gaseous arsenides, which helps to reduce the introduction of impurities and improve purification efficiency.

[0048] In summary, during the purification process, elemental arsenic is heated to the sublimation point, the arsenic molecules detach from the solid surface and enter the vacuum environment, the arsenic molecules escape to the cold end, and condense to obtain elemental arsenic. Vacuum sublimation purification technology combined with precise temperature control and atmosphere management 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.

[0049] In the present invention, the temperature of the hot end may be 600-900° C., and the temperature of the cold end may be 400-700° C. 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.

[0050] 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.

[0051] For example, when the vacuum degree is 0.001 Pa, the temperature of the hot end may be 700°C, and the temperature of the cold end may be 400°C.

[0052] In some embodiments, the first reducing agent may not include aluminum powder; illustratively, the first reducing agent may include one or more of zinc powder, iron powder, and carbon powder, and the amount of the first reducing agent added is 1% to 5% of the mass of the crude arsenic.

[0053] Exemplarily, the first reducing agent may be iron powder.

[0054] In some embodiments, the purifying agent includes one or more of copper powder, cadmium powder, lead powder, and sulfuric acid, and the amount of the purifying agent added is 2-10% of the mass of the crude arsenic.

[0055] In some embodiments of the present invention, when the purifying agent is sulfuric acid, the concentration of the sulfuric acid may be 90-95%.

[0056] 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; in some preferred embodiments, the first reducing agent is carbon powder, and the purifying agent is copper powder; in some preferred embodiments, the first reducing agent is carbon powder, and the purifying agent is sulfuric acid.

[0057] In the present invention, the duration of hot-end sublimation is not less than 2 hours; further, the duration of hot-end sublimation can be 2 to 8 hours; illustratively, the duration of hot-end sublimation can be 6 to 8 hours.

[0058] In some embodiments, the mass ratio of elemental arsenic to the active metal material may be 1:1.3 to 1:1.8. For example, the mass ratio of crude arsenic to the metal material may be 1:1.3 to 1:1.4; for example, the mass ratio of crude arsenic to the metal material may be 1:1.3.

[0059] In some embodiments, the purity level of elemental arsenic may be 3N5 or above; illustratively, the purity of elemental arsenic may be 99.5%.

[0060] In some embodiments, the elemental arsenic can be crushed and sieved to 200-400 meshes before being mixed with the active metal material. The particle size of the active metal material can be 200-400 meshes.

[0061] In the present invention, the active metal material may include zinc powder, magnesium powder, and aluminum powder. For example, the active metal material may be zinc powder.

[0062] In the present invention, a second reducing agent may be added to the melting reaction. The second reducing agent may include one or more of activated carbon, carbon black, and graphite powder. The amount of the second reducing agent added is 0.1-0.5% of the mass of elemental arsenic.

[0063] In some embodiments, the vacuum degree in the second vacuum environment can be 0.001~1Pa, which is a vacuum environment.

[0064] 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.

[0065] 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.

[0066] In 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 their 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.

[0067] In 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 utilized to achieve the maximum separation of arsenic and antimony, so that the antimony content in the metal arsenide product is infinitely 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.

[0068] 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.

[0069] In the present invention, the duration of the melting reaction can be 5 to 12 hours.

[0070] 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 S1, 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.

[0071] 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.

[0072] Also illustratively, the inert atmosphere includes one of nitrogen or argon.

[0073] S2, the metal arsenide is mixed with sulfuric acid in a third vacuum environment to obtain gaseous arsenide through a gas generation reaction.

[0074] The gaseous arsenic compound includes arsine.

[0075] 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%.

[0076] In some embodiments, the vacuum degree of the third vacuum environment is 1-100 Pa.

[0077] The formation of the third vacuum environment may include the following steps: S21, evacuating the gas production reaction device, and then introducing an inert gas into the device to normal pressure; S22, repeating the step S21 at least 2 times or 2 to 4 times; S23, evacuating the normal pressure device to 1 to 100 Pa to obtain the third vacuum environment. The inert gas may include nitrogen or argon. After evacuating, nitrogen or argon is filled to normal pressure, and the process is repeated several times to ensure the stability of the reaction system, and finally evacuating to a vacuum environment of 1 to 100 Pa, so that the gas production reaction is carried out under the most ideal conditions, effectively suppressing the occurrence of side reactions.

[0078] Exemplarily, in step S2, the vacuum degree in the gas production reaction device can be evacuated to 1-50 Pa.

[0079] In some embodiments, the rate of addition of sulfuric acid during the gas production reaction is 50~200mL / min, and the rate of generation of arsine is 1~3L / min; in some embodiments, the duration of the gas production reaction can be 30~120min; in some specific embodiments, the duration of the gas production reaction can be 40~80min.

[0080] In other embodiments, sulfuric acid may be added into the third vacuum environment through a liquid inlet device.

[0081] 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.

[0082] like Figure 6 As shown, the liquid inlet device can also be a combination of a metering pump and a pneumatic ball valve, wherein 1 is a first pneumatic ball valve, 2 is a metering pump, and 3 is a second pneumatic ball valve.

[0083] 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 arsine gas, which is suitable for subsequent purification to prepare electronic grade high-purity arsine.

[0084] 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.

[0085] Exemplarily, the negative pressure device may be a Venturi negative pressure device.

[0086] 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.

[0087] In some embodiments, the gas production reaction parameters in S2 are controlled as follows:

[0088] Table 1 Parameter control during gas production reaction

[0089]

[0090] 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.

[0091] In summary, in step S2 of the present invention, vacuum environment maintenance, precise control of reaction parameters and drying and dehydration technology are creatively used to coordinately optimize the reaction process of metal arsenide and sulfuric acid. Specifically, first, a low vacuum environment is conducive to the volatilization of arsine gas. Arsine has a low boiling point and is easily decomposed or reacted with other substances at normal pressure, and a low vacuum can reduce the partial pressure of the gas in the reactor, so that arsine quickly volatilizes and escapes from the reaction area, avoiding arsine from mixing with other components (such as sulfuric acid gas or other impurity gases) in the reaction system, and reducing the occurrence of side reactions. And low vacuum helps to reduce impurity generation. When the reaction is carried out under low vacuum, the outside air is effectively isolated to prevent arsine from oxidizing 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. 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 more rapid, thereby improving the reaction efficiency. That is, the third vacuum environment significantly reduces the moisture and oxygen concentrations in the reaction environment, reduces unnecessary side reactions, and ensures that the reaction between metal arsenide and sulfuric acid can 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, the precise control of the reaction parameters can regulate the reaction process and improve the yield and purity of arsine. Finally, the setting of the drying and dehydration device further reduces 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 in traditional processes, significantly improve the yield and purity of arsine, effectively improve the quality and reaction efficiency of arsine, and is particularly suitable for large-scale production needs in the semiconductor industry, thereby having a high industrial application value, and providing a more economical and efficient way for the production of electronic-grade arsine.

[0092] The present invention also provides an application of the method for preparing gaseous arsenide from metal arsenide as described above in the preparation of electronic grade arsine.

[0093] In order to facilitate those skilled in the art to further understand the present invention, examples are given below:

[0094] Example 1

[0095] 1. First, place 100g of crude arsenic, 5g of carbon powder, and 10g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and add the mixed arsenic material into a vacuum container. The elemental quantitative analysis results of crude arsenic are as follows: Figure 1 As shown, according to Figure 1Analysis shows that the Sb content in crude arsenic 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 oxygen-containing crude arsenic sample is analyzed, and it is 2N grade oxygen-containing crude arsenic.

[0096] The elemental content of crude arsenic is as follows Figure 2 As shown, the crude arsenic was fully scanned for element content and the purity was analyzed using the difference method. Figure 2 The results of elemental quantitative analysis show that Sb is the main impurity in crude arsenic, with an impurity content of up to 0.18%. Other important impurities include Ca, Fe, K, Na, Se, etc., with content of 0.0019%, 0.0053%, 0.0010%, 0.0038%, and 0.0037%, respectively;

[0097] XRD phase analysis of crude arsenic Figure 3 As shown, according to Figure 3 It can be observed that the mineral composition of crude arsenic mainly contains elemental arsenic as well as a large amount of arsenic oxide.

[0098] 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.

[0099] 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.

[0100] The purity of the purified arsenic powder is 99.95%, the antimony content is 286.5 mg / kg, and the oxygen content is 0.31%.

[0101] Example 2

[0102] Compared with Example 1, only the dosage of the first reducing agent in step 1 is changed:

[0103] 1. First, place 100 g of crude arsenic, 3 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.

[0104] 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.

[0105] 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 a purified arsenic powder product that meets the requirements.

[0106] The purity of the purified arsenic powder is 99.95%, the antimony content is 265.2 mg / kg, and the oxygen content is 0.38%.

[0107] Example 3

[0108] Compared with Example 1, only the dosage of the first reducing agent in step 1 is changed:

[0109] 1. First, place 100g of crude arsenic, 1g of carbon powder and 10g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and add the mixed arsenic material into a vacuum container.

[0110] 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.

[0111] 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 a purified arsenic powder product that meets the requirements.

[0112] The purity of the purified arsenic powder is 99.95%, the antimony content is 234.3 mg / kg, and the oxygen content is 0.47%.

[0113] Example 4

[0114] Compared with Example 1, only the temperature of the hot and cold ends in step 2 is changed:

[0115] 1. First, place 100 g of crude arsenic, 5 g of carbon powder and 10 g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and then add the mixed arsenic material into a vacuum container.

[0116] 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.

[0117] 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 a purified arsenic powder product that meets the requirements.

[0118] The purity of the purified arsenic powder is 99.99%, the antimony content is 180.7 mg / kg, and the oxygen content is 0.36%. The purified 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-volatility impurities such as antimony were volatilized from the crude arsenic by the first vacuum environment in vacuum coordination with the first reducing agent (i.e., carbon powder in this embodiment) and the purifying agent sublimation, thereby further improving the purity of arsenic.

[0119] Example 5

[0120] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the arsenic metal mixture into a vacuum container.

[0121] 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.

[0122] 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.).

[0123] In terms of 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 the second reducing agent (i.e., the activated carbon powder in this embodiment) in the second vacuum environment, the impurities and oxygen content of the finally prepared metal arsenide are effectively controlled.

[0124] Example 6

[0125] Compared with Example 5, only the melting temperature in step 2 is changed:

[0126] 1. First, place 100 g of the elemental arsenic prepared in Example 1 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 elemental arsenic, mix them thoroughly with a mixer, and add the arsenic metal mixture into a vacuum container.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] Example 7

[0131] Compared with Example 5, only the melting temperature in the step is changed:

[0132] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0133] 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.

[0134] 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 (i.e., by comparing the measured XRD peaks with the standard PDF card, comparing the high degree of overlap between the main peaks, secondary peaks, etc.).

[0135] 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.

[0136] Example 8

[0137] Compared with Example 5, only the melting temperature in the step is changed:

[0138] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0139] 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.

[0140] 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 meshes. Finally, a metal arsenide particle product that meets the requirements is obtained. 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 (d), the crystal structure conforms to the standard Zn3As2 card configuration and contains a certain amount of ZnO structure (i.e., by comparing the measured XRD peaks with the standard PDF card, comparing the high overlap of the main peaks, secondary peaks, etc.).

[0141] 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.

[0142] Example 9

[0143] Compared with Example 5, only the ratio of the arsenic active metal material in step 1 is changed:

[0144] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 150 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the crude arsenic containing oxygen, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] Example 10

[0149] Compared with Example 5, only the vacuum conditions in step 2 are changed:

[0150] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] Embodiment 11

[0155] Compared with Example 5, only the type of active metal material in step 1 is changed:

[0156] 1. First, place 100g of oxygen-containing crude arsenic and 130g of magnesium powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of oxygen-containing crude arsenic, mix them thoroughly through a mixer, and add the mixture into a vacuum container.

[0157] 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.

[0158] 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%.

[0159] 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.

[0160] Example 12

[0161] Compared with Example 5, only the type of the second reducing agent in step 1 is changed:

[0162] 1. First, place 100g of crude arsenic and 130g of zinc powder in an inert atmosphere, add 0.1% carbon black powder of the mass of elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0163] 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.

[0164] 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%.

[0165] 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.

[0166] Embodiment 13

[0167] 1. First, 500 g of the metal arsenide prepared in Example 5 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.

[0168] 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 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.

[0169] 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 arsine gas with extremely low moisture content (<0.1%), and the product quality meets the requirements.

[0170] Embodiment 14

[0171] Compared to Example 13, only step 2 is changed; that is, the rate of addition of sulfuric acid is changed:

[0172] 1. First, 500 g of the metal arsenide prepared in Example 5 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.

[0173] 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.

[0174] 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. The arsine gas with extremely low moisture content (<0.1%) meets the product quality requirements.

[0175] Embodiment 15

[0176] Compared with Example 13, only step 1 is changed; that is, the dosage of the metal arsenide is changed:

[0177] 1. First, 300 g of the metal arsenide prepared in Example 5 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.

[0178] 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.

[0179] 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 arsine gas with extremely low moisture content (<0.1%) is obtained, and the product quality meets the requirements.

[0180] Example 16

[0181] Compared with Example 1, only the type of the first reducing agent in step 1 is changed:

[0182] 1. First, place 100 g of crude arsenic, 5 g of zinc 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.

[0183] 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.

[0184] 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 a purified arsenic powder product that meets the requirements.

[0185] The purity of the purified arsenic powder is 99% and the antimony content is 564.5 mg / kg.

[0186] Comparative Example 1

[0187] Compared with Example 1, only the type of the first reducing agent in step 1 is changed:

[0188] 1. First, place 100 g of crude arsenic, 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 then add the mixed arsenic material into a vacuum container.

[0189] 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.

[0190] 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 a purified arsenic powder product that meets the requirements.

[0191] In this comparative example, the purity of the purified arsenic powder is 99.6%, 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.

[0192] Comparative Example 2

[0193] Compared with Example 1, only the temperature of the hot and cold ends in step 2 is changed:

[0194] 1. First, place 100 g of crude arsenic, 5 g of carbon powder and 10 g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and then add the mixed arsenic material into a vacuum container.

[0195] 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.

[0196] Comparative Example 3

[0197] Compared with Example 1, only the vacuum degree in step 2 is changed:

[0198] 1. First, place 100 g of crude arsenic, 5 g of carbon powder and 10 g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and then add the mixed arsenic material into a vacuum container.

[0199] 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.

[0200] Comparative Example 4

[0201] Compared with Example 1, only the purifying agent is added without adding the first reducing agent:

[0202] 1. First, place 100 g of crude arsenic and 10 g of copper powder in an inert atmosphere, mix them thoroughly with a mixer to obtain a mixed arsenic material, and then add the mixed arsenic material into a vacuum container.

[0203] 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.

[0204] 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.

[0205] Comparative Example 5

[0206] Compared to Example 5, only the melting temperature in step 2 was changed:

[0207] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the crude arsenic containing oxygen, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0208] 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.

[0209] 3. Take out the metal arsenide block under an inert atmosphere, crush it through a ball mill and then sieve it. 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 5As shown in (b), the crystal structure is mainly a single-element As configuration card configuration (that is, by comparing the measured XRD peak with the standard PDF card, comparing the high overlap of the main peak, secondary peak, etc.).

[0210] 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.

[0211] Comparative Example 6

[0212] Compared with Example 5, only the reaction time and vacuum conditions in step 2 were changed:

[0213] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0214] 2. The vacuum container containing the mixed material 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 at 800°C and the reaction time is 2 hours. 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.

[0215] Comparative Example 7

[0216] Compared to Example 5, only the reaction time in step 2 was changed:

[0217] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0218] 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.

[0219] Comparative Example 8

[0220] Compared with Example 5, only the vacuum degree in step 2 is changed:

[0221] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0222] 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.

[0223] 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%.

[0224] Comparative Example 9

[0225] Compared with Example 5, only the vacuum degree in step 2 is changed:

[0226] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0227] 2. The vacuum container with the mixed material 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 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.

[0228] 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.

[0229] Comparative Example 10

[0230] Compared with Example 5, only the ratio of the arsenic active metal material in step 1 is changed:

[0231] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 100 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0232] 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.

[0233] 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 to finally obtain a mixed particle product of Zn3As2 and ZnAs2. The chemical composition of the metal arsenide includes (wt%): O 2.33; Zn 49.01; As 48.93; Sb 0.22.

[0234] Comparative Example 11

[0235] Compared with Example 13, only the vacuum conditions in step 1 were changed:

[0236] 1. First, 500 g of the metal arsenide prepared in Example 5 was placed in a reaction device without vacuum replacement.

[0237] 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.

[0238] 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 arsine gas obtained (>1.3%) did not meet the requirements.

[0239] Comparative Example 12

[0240] Compared to Example 13, only step 2 is changed; that is, the rate of addition of sulfuric acid is changed:

[0241] 1. First, 500 g of the metal arsenide prepared in Example 5 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.

[0242] 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.

[0243] 3. The temperature of the drying and dehydration device is set to 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 arsine gas finally obtained (>0.6%) does not meet the requirements.

[0244] Comparative Example 13

[0245] Compared with Example 13, only step 3 is changed; that is, the drying and water removal device is not started:

[0246] 1. First, 500 g of the metal arsenide prepared in Example 5 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.

[0247] 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.

[0248] 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 arsine gas finally obtained (>2.1%) does not meet the requirements.

[0249] Comparative Example 14

[0250] Compared with Comparative Example 5, only the vacuum conditions in step 2 were changed:

[0251] 1. First, place 100 g of the elemental arsenic prepared in Example 1 and 130 g of zinc powder in an inert atmosphere, add 0.1% activated carbon powder of the mass of the elemental arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0252] 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.

[0253] Analysis example 1

[0254] The parameters of the metal arsenide used in Examples 13 to 15 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%.

[0255] Analysis example 2

[0256] The analysis of the parameters related to the preparation of arsine in Examples 13 to 15 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.

[0257] The above technical solutions of the present invention are only preferred embodiments of the present invention, and the patent scope of the present invention is not limited thereto. All equivalent structural changes made by using the contents of the present invention 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 preparing gaseous arsenide from metal arsenide, characterized in that: Includes steps: S1, crude arsenic, a first reducing agent, and a purifying agent are mixed to obtain a mixed arsenic material; then the mixed arsenic material is placed in a hot end of a closed first vacuum environment for sublimation, and condensates at a cold end of the first vacuum environment are collected to obtain elemental arsenic; the elemental arsenic is mixed with an active metal material to obtain an arsenic metal mixture; then the arsenic metal mixture is placed in a second vacuum environment for melting reaction to obtain metal arsenide; the vacuum pressure of the first vacuum environment is not greater than 1Pa, the temperature of the hot end of the first vacuum environment 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 melting reaction in the second vacuum environment is not less than 750°C, and the duration of the melting reaction is not less than 5h; the vacuum pressure in the second vacuum environment is 0.001-1Pa; the first reducing agent includes one or more of zinc powder, iron powder, and carbon powder; the purifying agent includes one or more of copper powder, cadmium powder, lead powder, and sulfuric acid; the mass ratio of the elemental arsenic to the active metal material is 1:1.3-1:1.8; S2, the metal arsenide is mixed with sulfuric acid in a third vacuum environment, and the temperature of the sulfuric acid in the environment is maintained at 20-40°C, and gaseous arsenide is obtained through a gas production reaction; wherein the sulfuric acid exists in the form of a sulfuric acid solution, and the mass concentration of the sulfuric acid solution is 5-20%; during the gas production reaction, the addition rate of the sulfuric acid solution is 50-200 mL / min.

2. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: The vacuum pressure of the third vacuum environment is 1-100 Pa; The formation of the third vacuum environment includes the following steps: S21, evacuating the device for the gas production reaction, and then introducing an inert gas into the device to normal pressure; S22, repeating step S21 at least twice; S23, evacuating the device at normal pressure to 1~100Pa to obtain the third vacuum environment.

3. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: In the third vacuum environment, in the reaction solution formed by mixing the metal arsenide and the sulfuric acid, the concentration of the metal arsenide is 0.1-0.5 mol / L.

4. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: The gaseous arsenic compound includes arsine; The step S2 further comprises: performing a dehydration treatment on the gaseous arsenide; the dehydration treatment comprises: passing the arsine into a drying dehydration device, wherein the temperature of the drying dehydration device is set to 0-100°C.

5. The method for preparing gaseous arsenide from metal arsenide according to claim 4, characterized in that: 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 in by the negative pressure device to maintain the vacuum pressure of the third vacuum environment.

6. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: The generation rate of the gaseous arsenide is 1-3 L / min.

7. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: The vacuum pressure in the first vacuum environment is 0.001-0.1 Pa.

8. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: The amount of the first reducing agent added is 1-5% of the mass of the crude arsenic; the amount of the purifying agent added is 2-10% of the mass of the crude arsenic.

9. The method for preparing gaseous arsenide from metal arsenide according to claim 1, characterized in that: A second reducing agent is added to the melting reaction, wherein the second reducing agent includes one or more of activated carbon, carbon black, and graphite powder, and the amount of the second reducing agent added is 0.1-0.5% of the mass of the elemental arsenic.

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