Preparation Method and Application of Metal Arsenide

Abstract

The present invention provides a method for preparing a metal arsenide and its application; the method for preparing the metal arsenide includes: performing a melting reaction on metal arsenic and an active metal in an environment with a vacuum degree of 0.001~1 Pa and a temperature of 750~950 °C to obtain a reaction product; cooling the reaction product to room temperature and pulverizing it under the protection of an inert gas to obtain the metal arsenide. The present invention effectively utilizes metal arsenic resources, significantly reduces arsenic emissions in the industrial process, and promotes environmental protection; by converting low-value metal arsenic and active metals into high-value metal arsenide products, it has a wide range of applications in semiconductor materials and electronic special gases; under vacuum conditions, the present invention significantly reduces the reaction temperature by lowering the triple point of arsenic and active metal reactants, improves the reaction rate, and at the same time, the reaction conditions are easy to control and the operation is simple, thereby reducing the overall preparation cost.

Description

Technical Field

[0001] The present invention relates to the field of preparation of metal arsenides, and particularly to a method for preparing metal arsenides and its application. Background Art

[0002] Metal arsenide is a compound semiconductor material with a direct bandgap and a high electron mobility, which makes it have broad application prospects in optoelectronic devices, arsenic electronic special gases and other fields. As a potential arsenic source, metal arsenide can be converted into arsenic electronic special gas through a controllable chemical process, and reducing impurities in the preparation process can effectively improve the purity of arsenic electronic special gas.

[0003] As a physical preparation method, the melting method directly melts and mixes raw materials at high temperature to achieve a more uniform composition distribution at the atomic scale; however, this method faces technical problems such as large differences in the melting points of raw materials and easy oxidation during the melting process. In addition, although technical means such as protecting alloy melting with an inert atmosphere or high-pressure alloy melting can alleviate the oxidation problem to a certain extent, these methods often lead to non-uniform phase combination of the synthesized products, ultimately affecting the gas production of arsenic electronic special gas.

[0004] In view of this, it is necessary to provide a method for preparing metal arsenides and its application to solve or at least alleviate the technical problems of residual oxygen in the raw material of crude arsenic containing oxygen and re-oxidation during the melting process affecting the purity of metal arsenide products. Summary of the Invention

[0005] The main object of the present invention is to provide a method for preparing metal arsenides and its application to solve the technical problems of residual oxygen in the raw material of crude arsenic containing oxygen and re-oxidation during the melting process affecting the purity of metal arsenide products.

[0006] To achieve the above object, the present invention provides a method for preparing metal arsenides, including:

[0007] Mixing and proportioning crude arsenic containing oxygen and metal materials to obtain an arsenic-metal mixture; the mass ratio of the crude arsenic containing oxygen to the metal materials is 1:1.3 to 1:1.8;

[0008] Placing the arsenic-metal mixture in a sealed vacuum container, heating the vacuum container to 750-950°C for a melting reaction to obtain metal arsenide; the vacuum container has a high-vacuum environment, and the vacuum degree of the high-vacuum environment is 0.001-1 Pa.

[0009] Further, the metal materials include active metal powder; the metal materials include one of magnesium material, zinc material, and aluminum material.

[0010] Further, it also includes: adding a reducing agent to the arsenic-metal mixture before or during the melting reaction to control the participation of the reducing agent in the melting reaction.

[0011] Further, the reducing agent includes one or more of activated carbon, carbon black, and graphite powder; the addition amount of the reducing agent is 1% to 5% of the mass of the oxygen-containing crude arsenic.

[0012] Further, the duration of the melting reaction is 5 to 12 hours; the purity of the oxygen-containing crude arsenic is 1N to 3N; the oxygen content of the oxygen-containing crude arsenic is not less than 5%; the purity of the metal material is not less than 3N.

[0013] Further, it also includes: after the metal arsenide melt obtained from the melting reaction is cooled to obtain a metal arsenide block, and then the metal arsenide block is sequentially crushed and screened in an inert gas atmosphere to obtain the metal arsenide.

[0014] Further, the crushing method includes ball milling; the duration of the ball milling is 6 to 12 hours.

[0015] Further, the temperature of the melting reaction is 800 to 950 °C, and the duration of the melting reaction is 6 to 10 hours.

[0016] Further, the vacuum degree in the vacuum container is 0.001 to 0.01 Pa.

[0017] The present invention also provides an application of the metal arsenide prepared by the preparation method of the metal arsenide described in any one of the above in the production of arsenic electronic special gases.

[0018] The beneficial effects of the present invention are as follows:

[0019] The present invention provides a method for preparing metal arsenide. The arsenic-metal mixture is melted by using a vacuum technology with a vacuum degree of 0.001~1 Pa. On the one hand, by adding a reducing agent, the oxidation and hydrolysis problems of crude arsenic containing oxygen during the preparation process are effectively avoided, the introduction of impurities is reduced, and the chemical purity and crystal quality of the metal arsenide are significantly improved, providing a higher-quality raw material for the subsequent manufacture of arsenic electronic special gases. On the other hand, the vacuum environment can further inhibit the oxidation of arsenic caused by external oxygen, and cooperate with the temperature control to control the activity of the residual oxygen in the crude arsenic containing oxygen, jointly inhibiting the formation of arsenic oxide with a higher saturated vapor pressure and a faster evaporation rate, reducing the loss of arsenic while increasing the vapor pressure of arsenic, enhancing the reaction tendency between arsenic and metal, controlling the reaction selectivity and maintaining the gaseous arsenic and metal metering in the reaction system, and generating a metal arsenide with uniform purity and composition. Moreover, the surface tension of the molten system changes in the vacuum environment, and the uniform mixing effect of melting effectively reduces the phase separation phenomenon caused by the difference in the melting points of the system raw materials, further ensuring the uniformity of the metal arsenide product.

[0020] The present invention controls the temperature of the melting reaction at 750~950 °C, and optimizes the reaction process by using the transformation between the α-phase and β-phase of Zn3As2 within this temperature range. The β-phase has higher stability and stronger reaction activity than the α-phase, which can effectively increase the reaction rate between arsenic and zinc and promote the formation of metal arsenide. In addition, due to the β-phase having a more compact crystal structure, the doping of impurity elements (such as oxygen elements) is reduced, and the temperature control at 750~950 °C also effectively improves the purity of the metal arsenide. Description of the Drawings

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

[0022] Figure 1 It is a flowchart for the preparation of metal arsenide in an embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of the element content of the crude arsenic containing oxygen raw material in Examples 1~11 and Comparative Examples 1~9 of the present invention.

[0024] Figure 3 It is a schematic SEM morphology diagram of the crude arsenic containing oxygen raw material in Examples 1~11 and Comparative Examples 1~9 of the present invention. Among them, Figure 3 (a) is the SEM image of the crude arsenic containing oxygen at a scale of 20 microns, Figure 3 (b) is the SEM image of the crude arsenic containing oxygen at a scale of 1 micron.

[0025] The realization, functional features and advantages of the present invention will be further described in conjunction with the embodiments with reference to the accompanying drawings. Specific embodiments

[0026] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0027] Moreover, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0028] Those skilled in the art should know that, as an explanation of this application document, without affecting the actual understanding of the technical solutions of this application, 2 Theta can be expressed as twice the diffraction angle, Intensity can be expressed as intensity or saturation, XRD can be expressed as X-ray diffraction, SEM can be expressed as scanning electron microscope, ICP can be expressed as inductively coupled plasma, and ICP-OES can be expressed as inductively coupled plasma emission spectrometer.

[0029] In order to solve the technical problems such as the residual oxygen in the existing oxygen-containing crude arsenic raw materials and the re-oxidation during the melting process, which affect the purity of metal arsenide products, the uneven metal arsenide phases, and the large amount of by-products, and the large difference in the melting points of raw materials and the easy oxidation during the melting process in the preparation process of metal arsenides, as Figure 1 shown, the present invention provides a method for preparing metal arsenide, including the steps of:

[0030] S1, mixing and proportioning oxygen-containing crude arsenic and metal materials to obtain an arsenic-metal mixture.

[0031] In some embodiments, the mass ratio of oxygen-containing crude arsenic to the metal materials is 1:1.3 to 1:1.8.

[0032] In the case where the metal material is zinc material, by precisely controlling the arsenic-to-metal ratio and combining with the application of a vacuum environment, the efficient generation of Zn3As2 can be promoted, and the formation of by-products As2O3 and ZnAs2 can be avoided. The vacuum condition (0.001 - 1 Pa) significantly reduces the oxygen content in the environment, inhibits the formation of oxides such as As2O3, and at the same time enhances the vapor pressure of arsenic, making it easier for arsenic to react with active metals to form Zn3As2. The appropriate arsenic-to-metal ratio can fully play its role in the vacuum environment, effectively control the reaction selectivity, improve the formation rate and purity of Zn3As2, so as to achieve the purpose of optimizing product quality.

[0033] Exemplarily, the mass ratio of oxygen-containing crude arsenic to the metal material can be 1:1.3 - 1:1.7; Exemplarily, the mass ratio of oxygen-containing crude arsenic to the metal material can be 1:1.3 - 1:1.5; Exemplarily, the mass ratio of oxygen-containing crude arsenic to the metal material can be 1:1.3 - 1:1.4.

[0034] Oxygen-containing crude arsenic is the product of the reduction section of arsenic oxide products and preliminary purification. Its main source is the arsenic-containing waste residues such as arsenic soot in non-ferrous metal smelting processes through recovery and processing. Its main impurity is antimony (Sb), with a content between 10 - 1500 ppm, and it also contains impurities such as silicon (Si), sulfur (S), and boron (B). Its physical properties are similar to those of crude arsenic, but because it contains arsenic oxide components, it has higher chemical toxicity. The recycling of oxygen-containing crude arsenic can reduce environmental pollution, realize resource reuse, reduce costs, and meet the needs of different industries for high-purity arsenic through further purification. Its production cost is low, the raw material source is wide and the cost is low, the recycling process is simple, and it can also bring environmental benefits. Currently, the price of 2N crude arsenic on the market is about 30 - 200 yuan per kilogram, and because of its high oxygen content, oxygen-containing crude arsenic is difficult to be directly applied as elemental arsenic. Currently, the price is only 10 - 20 yuan per kilogram, which has significant cost advantages and broad application prospects for the reduction and reuse of oxygen-containing crude arsenic.

[0035] Exemplarily, the purity of oxygen-containing crude arsenic is not less than 1N grade; Exemplarily, the purity grade of oxygen-containing crude arsenic can be 1N - 3N grade.

[0036] In the present invention, the oxygen content of oxygen-containing crude arsenic is not less than 5%; In some embodiments, the oxygen content of oxygen-containing crude arsenic can be 5 - 10%.

[0037] It should be noted that the purity of oxygen-containing crude arsenic is obtained by measuring the impurity content through ICP full-element determination, excluding the oxygen content; the oxygen content is listed separately through an oxygen content analyzer test.

[0038] Exemplarily, the crude arsenic containing oxygen can be obtained by crushing, and the particle size of the crude arsenic containing oxygen can be 200-400 mesh. For example, the initial particle size of the crude arsenic containing oxygen is 0.5-3 cm; the crude arsenic containing oxygen is sieved after the crushing, and the particle size after the sieving is 200-400 mesh.

[0039] The utilization of the crude arsenic containing oxygen has important environmental significance. Arsenic is a toxic heavy metal element. If directly discharged into the environment without treatment, it will cause serious damage to the soil, water source and ecosystem. Secondly, the reuse of the crude arsenic containing oxygen helps to reduce the exploitation of natural resources, promotes the recycling of resources, and conforms to the concept of sustainable development. In addition, by converting the crude arsenic containing oxygen into valuable metal arsenide products, it can bring economic benefits to relevant enterprises, and at the same time promotes the development and application of environmental protection technologies.

[0040] In the embodiments and comparative examples of the present invention, the purity of the metal material is not less than 3N grade.

[0041] Exemplarily, the particle size of the metal material can be 200-400 mesh.

[0042] In some specific embodiments, the crude arsenic containing oxygen and the metal material can be placed in an inert atmosphere in proportion and sufficiently ground and mixed by a mixer to obtain an arsenic-metal mixture.

[0043] In the present invention, the metal material includes one of magnesium material, zinc material and aluminum material. In some embodiments, the magnesium material, zinc material and aluminum material can be magnesium powder, zinc powder and aluminum powder respectively.

[0044] S2, placing the arsenic-metal mixture in a vacuum container, heating the vacuum container to 750-950 °C for a melting reaction to obtain a metal arsenide; the vacuum degree in the vacuum container is 0.001-1 Pa.

[0045] In the present invention, the temperature of the melting reaction can be controlled within 750~950°C. Through thermodynamic analysis, it can be seen that when the temperature of the melting reaction is in the range of 750°C to 950°C, the phase structure of the Zn3As2 in the system changes significantly. Especially at a temperature near 800°C, the α-phase and β-phase of Zn3As2 will transform, thus 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, due to the β-phase having a more compact crystal structure, the doping of other impurity elements (such as oxygen element) is reduced. Therefore, using the phase transformation process near this temperature to prepare metal arsenides can also effectively improve its purity. Considering the temperature, reaction rate and phase transformation characteristics in the phase diagram comprehensively, too low temperature (<750°C) results in low reaction efficiency and it is difficult to prepare high-quality zinc arsenide products without phase change effect; while too high temperature (>950°C) leads to high energy consumption. Based on the oxygen-containing characteristics of the oxygen-containing crude arsenic in this application, when the melting temperature is higher than 950°C, the saturated vapor pressure of the oxidized impurity is large and the volatilization rate is fast, making it difficult to be fully reduced. In addition, too high temperature also poses challenges to the selection of the heating equipment material, so it is not the preferred temperature range for industrialization either; the upper limit of the melting reaction temperature in the present invention is set at 950°C, and the ideal temperature is near 800°C, which can effectively avoid the formation of arsenic oxide from the residual oxygen in the oxygen-containing crude arsenic, contribute to the preparation of high-quality zinc arsenide products, and make the oxygen content of the final arsenide product <1%.

[0046] In the present invention, the temperature of the melting reaction can be controlled within 750°C~850°C, and the arsenic-antimony separation can be maximally achieved by utilizing the significant difference in the saturated vapor pressure and the maximum volatilization rate between arsenic and antimony, making the antimony content in the metal arsenide product infinitely close to zero. It should be noted that since arsenic and antimony both belong to Group V A elements and have similar chemical properties, it is difficult to separate them under conventional conditions, increasing the complexity of purification.

[0047] Exemplarily, the temperature of the melting reaction can be controlled within 770~830°C or 800~950°C; additionally exemplarily, the temperature of the melting reaction can also be controlled within 780~820°C.

[0048] In the present invention, a reducing agent can be added to the arsenic-metal mixture before or during the melting reaction to control the participation of the reducing agent in the melting reaction; specifically, a reducing agent can be added to the arsenic-metal mixture before the melting reaction; for example: after mixing the reducing agent and the arsenic-metal mixture, they are placed together in the vacuum container for the melting reaction.

[0049] In some embodiments of the present invention, the reducing agent includes one or more of activated carbon, carbon black, and graphite powder; the addition amount of the reducing agent is 1~5% of the mass of the oxygen-containing crude arsenic.

[0050] In some specific embodiments of the present invention, the reducing agent may include activated carbon and / or graphite powder.

[0051] In the present invention, the duration of the melting reaction may be 5 to 12 h; for example, the duration of the melting reaction may be 6 to 10 h, and further may be 6 to 8 h.

[0052] In some embodiments, the vacuum degree of the vacuum container may be 0.001 to 0.01 Pa to further reduce the oxygen content and improve the product purity.

[0053] It should be understood that a high-vacuum environment can effectively inhibit the occurrence of oxidation reactions, avoid the reaction of oxygen and water vapor with arsenic, thereby reducing the generation of oxidation by-products. In addition, in a high-vacuum environment with extremely low pressure, the melting point of metal arsenide can be significantly reduced, further improving the uniformity and purity of metal arsenide. High vacuum can also promote the efficient evaporation and deposition process of metal arsenide by reducing the influence of impurities in the air, and improve the efficiency of converting arsenic source into arsenic electronic special gas. When an external reducing agent enters the reaction system, it can react with the oxygen in the oxide to effectively remove the oxygen from the metal arsenide, thereby further purifying the metal arsenide.

[0054] In some specific embodiments, the arsenic-metal mixture can be added to a vacuum container, sealed and evacuated, and then placed in a furnace body. After setting the temperature at 750 to 950 °C and melting for more than 5 h, it is cooled to obtain a metal arsenide block.

[0055] According to the morphology of the whole-process metal arsenide, the metal arsenide includes metal arsenide melt, metal arsenide block, and metal arsenide particle product. Specifically: in step S2, the metal arsenide block is obtained after the metal arsenide melt obtained by the melting reaction is cooled. The metal arsenide block is crushed and screened in an inert gas atmosphere to obtain the particle product of metal arsenide; the particle size of the particle product of metal arsenide can be 0.6 to 8 mm.

[0056] For example, the crushing method includes ball milling, the duration of the ball milling is 6 to 12 h, and the particle size of the screening is 200 to 400 mesh.

[0057] Another example is that the inert gas includes one of nitrogen or argon.

[0058] The present invention also provides an application of the metal arsenide prepared by the preparation method of the metal arsenide described in any one of the above in the production of arsenic electronic special gas.

[0059] As an important semiconductor electronic gas for growing gallium arsenide (GaAs) and other arsenic-based compound semiconductor materials in the chemical vapor deposition (CVD) process, arsenic electronic special gas is a class of important semiconductor electronic gases. As a potential arsenic source, metal arsenide can be converted into arsenic electronic special gas through a controllable chemical process, and reducing impurities in the preparation process can effectively improve the purity of arsenic electronic special gas.

[0060] For a further understanding of the present invention, the following is an example for illustration:

[0061] Example 1

[0062] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of oxygen-containing crude arsenic, mix well through a mixer, and add the arsenic metal mixture into a vacuum container.

[0063] 2. Evacuate the vacuum container containing the arsenic metal mixture, seal it after the vacuum degree reaches 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature at 800 °C, and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0064] 3. Take out the metal arsenide block in an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. By mass fraction, the oxygen element content in the metal arsenide is 0.53%, the antimony element content is 0.04%, the total content of arsenic + zinc elements > 99%, the product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0065] Example 2

[0066] Compared with Example 1, only change the melting reaction temperature in Step 2:

[0067] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of oxygen-containing crude arsenic, mix well through a mixer, and add the arsenic metal mixture into a vacuum container.

[0068] 2. Evacuate the vacuum container with the arsenic metal mixture, seal it after the vacuum degree reaches 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature at 780 °C, and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0069] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time to 6 h and the mesh number of the sieve to 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0070] By mass fraction, the oxygen element content in the metal arsenide is 0.49%, the antimony element content is 0.07%, and the total content of arsenic + zinc elements > 99%.

[0071] Example 3

[0072] Compared with Example 1, only change the melting reaction temperature in Step 2:

[0073] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, fully mix through a mixer, and add the arsenic metal mixture into a vacuum container.

[0074] 2. Evacuate the vacuum container with the arsenic metal mixture, seal it after the vacuum degree reaches 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature to 820 °C, the reaction time to 6 h, and cool it after the melting reaction ends to obtain a metal arsenide bulk.

[0075] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time to 6 h and the mesh number of the sieve to 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0076] By mass fraction, the oxygen element content in the metal arsenide is 0.67%, the antimony element content is 0.03%, and the total content of arsenic + zinc elements > 99%.

[0077] Example 4

[0078] Compared with Example 1, only change the melting reaction temperature in Step 2:

[0079] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, fully mix through a mixer, and add the mixture into a vacuum container.

[0080] 2. Evacuate the vacuum container with the mixture, seal it after the vacuum degree reaches 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature to 900 °C, the reaction time to 6 h, and cool it after the melting reaction ends to obtain a metal arsenide bulk.

[0081] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then sieve it. Set the ball milling time to 6 h and the sieve mesh size to 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0082] By mass fraction, the oxygen element content in the metal arsenide is 0.98%, the antimony element content is 0.48%, and the total content of arsenic + zinc elements > 99%.

[0083] Example 5

[0084] Compared with Example 1, only change the ratio of arsenic to metal materials in Step 1:

[0085] 1. First, place 100 g of oxygen-containing crude arsenic and 150 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture to a vacuum container.

[0086] 2. Evacuate the vacuum container with the mixture. After the vacuum degree is pumped to 0.001 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature to 800 °C and the reaction time to 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide bulk.

[0087] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then sieve it. Set the ball milling time to 6 h and the sieve mesh size to 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%, the crystal structure conforms to the standard Zn3As2 card configuration, and only contains a small amount of elemental active metal.

[0088] By mass fraction, the oxygen element content in the metal arsenide is 0.51%, the antimony element content is 0.07%, and the total content of arsenic + zinc elements > 99%.

[0089] Example 6

[0090] Compared with Example 1, only change the ratio of arsenic to metal materials in Step 1:

[0091] 1. First, place 100 g of oxygen-containing crude arsenic and 170 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture to a vacuum container.

[0092] 2. Evacuate the vacuum container with the mixture. After the vacuum degree is pumped to 0.001 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature to 800 °C and the reaction time to 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide bulk.

[0093] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time to 6 h and the mesh number of the sieve to 6 mesh. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%, the crystal structure conforms to the standard Zn3As2 card configuration, and it only contains a certain amount of elemental active metal.

[0094] By mass fraction, the oxygen element content in the metal arsenide is 0.34%, the antimony element content is 0.09%, and the total content of arsenic + zinc elements > 99%.

[0095] Example 7

[0096] Compared with Example 1, only change the vacuum condition in Step 2:

[0097] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0098] 2. Evacuate the vacuum container with the mixture. After the vacuum degree is pumped to 1 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature to 800 °C and the reaction time to 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide bulk, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0099] 3. Take out the metal arsenide bulk under an inert atmosphere, crush it through a ball milling device and then screen it. Set the ball milling time to 6 h and the mesh number of the sieve to 6 mesh. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%.

[0100] By mass fraction, the oxygen element content in the metal arsenide is 0.67%, the antimony element content is 0.23%, and the total content of arsenic + zinc elements > 99%.

[0101] Example 8

[0102] Compared with Example 1, only change the type of active metal material in Step 1:

[0103] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of magnesium powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0104] 2. Evacuate the vacuum container containing the mixture 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 whose crystal structure conforms to the standard Mg3As2 card configuration.

[0105] 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%.

[0106] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.77%, the antimony content is 0.26%, and the total content of arsenic + magnesium is >99%.

[0107] Example 9

[0108] Compared with Example 1, only the type of active metal material in step 1 is changed:

[0109] 1. First, place 100g of oxygen-containing crude arsenic and 130g of aluminum powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0110] 2. Evacuate the vacuum container containing the 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, and the crystal structure conforms to the standard AlAs card configuration.

[0111] 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%.

[0112] In terms of mass fraction, the oxygen content in the metal arsenide is 0.68%, the antimony content is 0.33%, and the total content of arsenic + aluminum is >99%.

[0113] Example 10

[0114] Compared with Example 1, only the type of reducing agent in step 1 is changed:

[0115] 1. First, place 100g of oxygen-containing crude arsenic and 130g of zinc powder in an inert atmosphere, add 1% graphite powder of the mass of oxygen-containing crude arsenic, mix them thoroughly through a mixer, and add the mixture into a vacuum container.

[0116] 2. Evacuate the vacuum container containing the 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, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0117] 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%.

[0118] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.78%, the antimony content is 0.27%, and the total content of arsenic + zinc is >99%.

[0119] Embodiment 11

[0120] Compared with Example 1, only the type of reducing agent in step 1 is changed:

[0121] 1. First, place 100g of oxygen-containing crude arsenic and 130g of zinc powder in an inert atmosphere, add carbon black powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0122] 2. Evacuate the vacuum container containing the 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, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0123] 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%.

[0124] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.50%, the antimony content is 0.31%, and the total content of arsenic + zinc is >99%.

[0125] Comparative Example 1

[0126] Compared with Example 1, only the melting temperature in step 2 is changed:

[0127] 1. First, place 100g of oxygen-containing crude arsenic and 130g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0128] 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.

[0129] 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.

[0130] In terms of mass fraction, the oxygen content of the metal arsenide is 0.50%, the antimony content is 0.47%, and the total content of arsenic + zinc is >99%. At this temperature, arsenic has begun to volatilize and is densely coated on 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 and metal ratio in the subsequent metal arsenide. The product crystal structure of As:Zn=93.07:6.32 tends to be a card configuration of single arsenic.

[0131] Comparative Example 2

[0132] Compared with Comparative Example 1, only the vacuum conditions in step 2 were changed:

[0133] 1. First, place 100g of oxygen-containing crude arsenic and 130g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0134] 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.

[0135] Comparative Example 3

[0136] Compared with Example 1, the reaction time and vacuum conditions in step 2 are changed:

[0137] 1. First, place 100g of oxygen-containing crude arsenic and 130g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix them thoroughly with a mixer, and add the mixture into a vacuum container.

[0138] 2. The vacuum container with the mixed materials is not evacuated (i.e., at normal pressure) and then sealed. The sealed vacuum container is placed in a high-temperature furnace for a melting reaction. The reaction temperature is set at 800 °C and the reaction time is 2 h. The final product is not completely reacted and presents a two-phase structure of separate elemental arsenic and zinc, so the metal arsenide bulk after the reaction cannot be obtained.

[0139] Comparative Example 4

[0140] Compared with Example 1, only the reaction time in Step 2 is changed:

[0141] 1. First, 100 g of oxygen-containing crude arsenic and 130 g of zinc powder are placed in an inert atmosphere, and 1% of the mass of the oxygen-containing crude arsenic of activated carbon powder is added. They are fully mixed by a mixer, and the mixed materials are added into a vacuum container.

[0142] 2. The vacuum container with the arsenic-metal mixed materials is evacuated. After the vacuum degree reaches 0.001 Pa, it is sealed. The sealed vacuum container is placed in a high-temperature furnace for a melting reaction. The reaction temperature is set at 800 °C and the reaction time is 4 h. Due to the too short reaction duration, the final product is not completely reacted and presents a two-phase structure of separate elemental arsenic and zinc, so the metal arsenide bulk after the reaction cannot be obtained.

[0143] Comparative Example 5

[0144] Compared with Example 1, only the vacuum condition in Step 2 is changed:

[0145] 1. First, 100 g of oxygen-containing crude arsenic and 130 g of zinc powder are placed in an inert atmosphere, and 1% of the mass of the oxygen-containing crude arsenic of activated carbon powder is added. They are fully mixed by a mixer, and the mixed materials are added into a vacuum container.

[0146] 2. The vacuum container with the mixed materials is evacuated. After the vacuum degree reaches 100 Pa, it is sealed. The sealed vacuum container is placed in a high-temperature furnace for a melting reaction. The reaction temperature is set at 800 °C and the reaction time is 6 h. After the melting reaction is completed, it is cooled to obtain a metal arsenide bulk. Due to the relatively 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 gas production reaction for preparing high-purity arsenic from the product.

[0147] 3. The metal arsenide bulk is taken out under an inert atmosphere, crushed by a ball milling device and then sieved. The ball milling time is set at 6 h and the mesh number of the sieve is 6 meshes. Finally, metal arsenide particles are obtained. The product purity is 99% and the oxygen content is 2.62%.

[0148] Comparative Example 6

[0149] Compared with Example 1, only the vacuum condition in Step 2 is changed:

[0150] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0151] 2. Seal the vacuum container with the mixture without evacuating it (i.e., at normal pressure), place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature to 800 °C, and the reaction time to 6 h. After the melting reaction ends, cool to obtain a metal arsenide bulk. Since no vacuum condition is set, the Zn3As2 phase in the product is largely oxidized, and a large amount of arsenic oxide appears in the product, which has a very adverse effect on the subsequent gas-producing reaction for preparing high-purity arsenic.

[0152] 3. Take out the metal arsenide bulk in an inert atmosphere, crush it through a ball-milling device and then screen it. Set the ball-milling time to 6 h and the mesh number of the sieve to 6 mesh. Finally, obtain a metal arsenide / arsenic oxide mixed particle. The oxygen content of the product is 6.01%, and the product does not meet the requirements.

[0153] Comparative Example 7

[0154] Compared with Example 1, only change the ratio of arsenic and metal materials in Step 1:

[0155] 1. First, place 100 g of oxygen-containing crude arsenic and 100 g of zinc powder in an inert atmosphere, add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic, mix well through a mixer, and add the mixture into a vacuum container.

[0156] 2. Evacuate the vacuum container with the mixture, seal it after the vacuum degree is pumped to 0.001 Pa, place the sealed vacuum container in a high-temperature furnace for a melting reaction, set the reaction temperature to 800 °C, and the reaction time to 6 h. After the melting reaction ends, cool to obtain a metal arsenide bulk. Since the content of active metals in the raw materials is insufficient, in addition to Zn3As2, the phase structure of the product also contains some ZnAs2, which has a certain adverse effect on the subsequent gas-producing process for preparing high-purity arsenic, and the gas production decreases.

[0157] 3. Take out the metal arsenide bulk in an inert atmosphere, crush it through a ball-milling device and then screen it. Set the ball-milling time to 6 h and the mesh number of the sieve to 6 mesh. Finally, obtain a mixed particle product of Zn3As2 and ZnAs2. By mass fraction, the oxygen element content in the metal arsenide is 0.55%, the antimony element content is 0.26%, and the total content of arsenic + zinc elements > 99%.

[0158] Comparative Example 8

[0159] Compared with Example 1, only change the melting temperature in Step 2:

[0160] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, and add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic. Mix them thoroughly through a mixer, and then add the mixture into a vacuum container.

[0161] 2. Evacuate the vacuum container with the mixture. After the vacuum degree reaches 0.001 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 1000 °C and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0162] 3. Take out the metal arsenide block in an inert atmosphere. Crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a metal arsenide particle product that meets the requirements. The product purity reaches 99%, and the crystal structure conforms to the standard Zn3As2 card configuration (that is, by comparing the measured XRD peaks with the standard PDF card, comparing the positions and heights of the main peaks, secondary main peaks, etc. for coincidence).

[0163] By mass fraction, the oxygen element content in the metal arsenide is 2.90%, the antimony element content is 0.37%, and the total content of arsenic + zinc elements > 95%.

[0164] Comparative Example 9

[0165] Compared with Example 1, only change the melting temperature in Step 2:

[0166] 1. First, place 100 g of oxygen-containing crude arsenic and 130 g of zinc powder in an inert atmosphere, and add activated carbon powder with a mass of 1% of the mass of the oxygen-containing crude arsenic. Mix them thoroughly through a mixer, and then add the mixture into a vacuum container.

[0167] 2. Evacuate the vacuum container with the mixture. After the vacuum degree reaches 0.001 Pa, seal it. Place the sealed vacuum container in a high-temperature furnace for a melting reaction. Set the reaction temperature at 1050 °C and the reaction time at 6 h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0168] 3. Take out the metal arsenide block in an inert atmosphere. Crush it through a ball milling device and then screen it. Set the ball milling time at 6 h and the mesh number of the sieve at 6 meshes. Finally, obtain a metal arsenide particle product, and the product purity reaches 99%.

[0169] By mass fraction, the oxygen element content in the metal arsenide is 4.19%, the antimony element content is 0.31%, and the total content of arsenic + zinc elements > 95%. However, due to the too high temperature, the vapor pressure of arsenic oxide increases significantly, the volatilization of arsenic oxide intensifies, and it volatilizes directly from the reaction system without undergoing a reduction process, resulting in an increase in the oxygen content of the product, which has an adverse effect on the gas production of the subsequent gaseous arsenide preparation process.

[0170] Analysis Example 1

[0171] Characterization analysis of the crude arsenic containing oxygen used in Examples 1 - 11 and Comparative Examples 1 - 9:

[0172] 1. Perform elemental quantitative analysis on the crude arsenic containing oxygen, and the analysis results are as Figure 2 shown. It can be observed from Figure 2 the results that the Sb content is as high as 1326.2 ppm, which is the impurity element with the highest content. Other impurity elements include Si, S, B, etc., and their concentrations are 52.3 ppm, 4.6 ppm, 1.5 ppm respectively. In addition, the oxygen element content is relatively high, reaching 7.4%. Analyze the purity of the crude arsenic containing oxygen sample, and it is a 2N - grade crude arsenic containing oxygen.

[0173] 2. Perform SEM morphology analysis on the crude arsenic containing oxygen, and the analysis results are as Figure 3 shown. Among them, Figure 3 (a) is the SEM image of the crude arsenic containing oxygen at a scale of 20 microns, Figure 3 and (b) is the SEM image of the crude arsenic containing oxygen at a scale of 1 micron. It is found that the crude arsenic containing oxygen is mainly micron - sized fine particles after being crushed. High - magnification morphology observation of the crude arsenic containing oxygen reveals that it is mainly an octahedral structure.

[0174] In the above technical solutions of the present invention, the above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural transformations made under the technical concept of the present invention by using the content of the specification and drawings 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 a metal arsenide, characterized in that: include: The oxygen-containing crude arsenic and the metal material are mixed to obtain an arsenic-metal mixed material; the mass ratio of the oxygen-containing crude arsenic to the metal material is 1:1.3-1:1.8; the purity of the oxygen-containing crude arsenic is 1N-3N; the oxygen content of the oxygen-containing crude arsenic is not less than 5%; the metal material includes one of magnesium material, zinc material and aluminum material; The arsenic metal mixture is placed in a sealed vacuum container, and the vacuum container is heated to 750-950° C. for a melting reaction to obtain a metal arsenide; the vacuum container has a high vacuum environment, and the vacuum degree of the high vacuum environment is 0.001-1 Pa; the melting reaction is performed for more than 5 hours.

2. The method for preparing metal arsenide according to claim 1, characterized in that: Also includes: Before the melting reaction or during the melting reaction, a reducing agent is added to the arsenic metal mixture to control the reducing agent to participate in the melting reaction.

3. The method for preparing metal arsenide according to claim 2, characterized in that: The reducing agent includes one or more of activated carbon, carbon black, and graphite powder; the amount of the reducing agent added is 1-5% of the mass of the oxygen-containing crude arsenic.

4. The method for preparing metal arsenide according to claim 1, characterized in that: The duration of the melting reaction is 5 to 12 hours.

5. The method for preparing metal arsenide according to claim 1, characterized in that: Also includes: The metal arsenide melt obtained by the melting reaction is cooled to obtain a metal arsenide block, and then the metal arsenide block is crushed and sieved in sequence under an inert atmosphere to obtain the metal arsenide.

6. The method for preparing metal arsenide according to claim 5, characterized in that: The crushing method includes ball milling; the duration of the ball milling is 6 to 12 hours.

7. The method for preparing metal arsenide according to claim 1, characterized in that: The temperature of the melting reaction is 800-950° C., and the duration of the melting reaction is 6-10 hours.

8. The method for preparing metal arsenide according to claim 1, characterized in that: The vacuum degree in the vacuum container is 0.001~0.01Pa.

9. Use of a metal arsenide obtained by the method for preparing a metal arsenide according to any one of claims 1 to 8 in the production of arsenic electronic specialty gases.

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