Preparation method and application of metal arsenide

Abstract

The invention provides a preparation method and application of a metal arsenide. The preparation method of the metal arsenide comprises the following steps: performing a melting reaction on metal arsenic and active metal in an environment with a vacuum degree of 0.001-1Pa and a temperature of 750-950 DEG C to obtain a reaction product; and cooling the reaction product to normal temperature, and crushing under the protection of inert gas to obtain the metal arsenide. According to the method, metal arsenic resources are effectively utilized, so that arsenic emission in the industrial process is remarkably reduced, and environmental protection is promoted; low-value metal arsenic and active metal are converted into a high-value metal arsenide product, so that the metal arsenide product is widely applied to semiconductor materials and electronic special gas; under the vacuum condition, the reaction temperature is remarkably reduced and the reaction speed is increased by reducing the triphase point of the arsenic and active metal reactants, meanwhile, the reaction conditions are easy to control, and the operation is simple, so that the overall preparation cost is reduced.

Description

Technical Field

[0001] The present invention relates to the field of preparation of metal arsenides, and in particular to a preparation method and application of metal arsenides. Background Art

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

[0003] As a physical preparation method, the melting method directly melts and mixes the raw materials at high temperature to achieve a more uniform distribution of components at the atomic scale; however, this method faces technical difficulties in actual operation, such as large differences in the melting points of the raw materials and easy oxidation during the melting process. In addition, although the use of technical means such as inert atmosphere protection alloy melting or high-pressure alloy melting can alleviate the oxidation problem to a certain extent, these methods often lead to uneven phase combination of the synthetic product, which ultimately affects the gas production of arsenic electronic specialty gas.

[0004] In view of this, it is necessary to provide a method for preparing metal arsenides and their application, so as to solve or at least alleviate the technical problems that residual oxygen in oxygen-containing crude arsenic raw materials and reoxidation during the melting process affect the purity of metal arsenide products. Summary of the invention

[0005] The main purpose of the present invention is to provide a preparation method and application of metal arsenide to solve the technical problem that the residual oxygen in the oxygen-containing crude arsenic raw material and the reoxidation during the melting process affect the purity of the metal arsenide product.

[0006] To achieve the above object, the present invention provides a method for preparing a metal arsenide, comprising: Mixing oxygen-containing crude arsenic and a metal material 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 arsenic metal mixture is placed in a sealed vacuum container, and the vacuum container is heated to 750-950° C. for 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.

[0007] Furthermore, the metal material includes active metal powder; the metal material includes one of magnesium material, zinc material and aluminum material.

[0008] Furthermore, the method further comprises: adding a reducing agent to the arsenic metal mixture before or during the melting reaction to control the reducing agent to participate in the melting reaction.

[0009] Furthermore, 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.

[0010] Furthermore, 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%; and the purity of the metal material is not less than 3N.

[0011] Furthermore, the method further comprises: cooling the metal arsenide melt obtained by the melting reaction to obtain a metal arsenide block, and then successively crushing and screening the metal arsenide block in an inert atmosphere environment to obtain the metal arsenide.

[0012] Furthermore, the crushing method includes ball milling; the duration of the ball milling is 6 to 12 hours.

[0013] Furthermore, the temperature of the melting reaction is 800-950° C., and the duration of the melting reaction is 6-10 hours.

[0014] Furthermore, the vacuum degree in the vacuum container is 0.001~0.01Pa.

[0015] The present invention also provides an application of a metal arsenide prepared by the method for preparing a metal arsenide as described in any one of the above in the production of arsenic electronic specialty gas.

[0016] The beneficial effects of the present invention are as follows: The invention provides a method for preparing metal arsenide, which utilizes a vacuum technology with a vacuum degree of 0.001-1Pa to melt-treat an arsenic metal mixture. On the one hand, the oxidation and hydrolysis problems of oxygen-containing crude arsenic in the preparation process are effectively avoided by adding an external reducing agent, the introduction of impurities is reduced, the chemical purity and crystal quality of the metal arsenide are significantly improved, and a higher-quality raw material is provided 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 the activity of residual oxygen in the oxygen-containing crude arsenic is controlled by coordinated temperature control, so as to jointly inhibit the formation of arsenic oxide with higher saturated vapor pressure and faster volatilization rate, reduce the loss of arsenic and increase the vapor pressure of arsenic at the same time, enhance the reaction trend of arsenic and metal, control the reaction selectivity and maintain the measurement of gaseous arsenic and metal in the reaction system, and generate metal arsenide with uniform purity and composition. Moreover, the surface tension of the molten system changes under the vacuum environment, and the melting effect of uniform mixing effectively reduces the phase separation phenomenon caused by the difference in melting points of the system raw materials, and further ensures the uniformity of the metal arsenide product.

[0017] The present invention controls the temperature of the melting reaction at 750-950°C, and optimizes the reaction process by utilizing the transformation between the Zn3As2α phase and the β phase within this temperature range. 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 arsenide. In addition, because the β phase has a tighter crystal structure, the doping of impurity elements (such as oxygen) is reduced, and the temperature control of 750-950°C also effectively improves the purity of the metal arsenide. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0019] Figure 1 1 is a flow chart for preparing metal arsenide in one embodiment of the present invention.

[0020] Figure 2 It is a schematic diagram of the element content of the oxygen-containing crude arsenic raw material in Examples 1 to 11 of the present invention and Comparative Examples 1 to 9.

[0021] Figure 3 Schematic diagram of SEM morphology of oxygen-containing crude arsenic raw materials in Examples 1 to 11 of the present invention and Comparative Examples 1 to 9, wherein: Figure 3 (a) is the SEM image of oxygen-containing crude arsenic at a scale of 20 microns. Figure 3 (b) is the SEM image of oxygen-containing crude arsenic at a scale of 1 μm.

[0022] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with the implementation methods and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] 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 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.

[0025] Those skilled in the art should know that, as an explanation of the present application documents, without affecting the actual understanding of the technical solution of the present application, 2 Theta can be expressed as 2 times 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.

[0026] In order to solve the problems of the residual oxygen in the oxygen-containing crude arsenic raw material and the reoxidation during the melting process affecting the purity of the metal arsenide product, the uneven phase of the metal arsenide, the large number of by-products, the large difference in the melting point of the raw materials and the easy oxidation during the melting process in the preparation process of the metal arsenide, etc. Figure 1 As shown, the present invention provides a method for preparing metal arsenide, comprising the steps of: S1, mixing oxygen-containing crude arsenic and metal materials to obtain arsenic metal mixed material.

[0027] In some embodiments, the mass ratio of the oxygen-containing crude arsenic to the metal material is 1:1.3 to 1:1.8.

[0028] In the case where the metal material is zinc material, by precisely controlling the ratio of arsenic to metal and combining the application of a vacuum environment, the efficient generation of Zn3As2 can be promoted, and the generation of byproducts As2O3 and ZnAs2 can be avoided. 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 generate Zn3As2. The appropriate ratio of arsenic to metal can be fully utilized in a vacuum environment, effectively controlling the reaction selectivity, and improving the generation rate and purity of Zn3As2, thereby achieving the purpose of optimizing product quality.

[0029] Exemplarily, the mass ratio of the oxygen-containing crude arsenic to the metal material can be 1:1.3~1:1.7; exemplary, the mass ratio of the oxygen-containing crude arsenic to the metal material can be 1:1.3~1:1.5; exemplary, the mass ratio of the oxygen-containing crude arsenic to the metal material can be 1:1.3~1:1.4.

[0030] Oxygen-containing crude arsenic is the product of the reduction section of arsenic oxide products and preliminary purification. It is mainly obtained by recycling and processing arsenic-containing waste slag such as arsenic soot in the process of non-ferrous metal smelting. Its main impurity is antimony (Sb), with a content between 10 and 1500 ppm. 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 recycling, reduce costs, and meet the needs of different industries for high-purity arsenic through further purification. It has low production costs, a wide range of raw material sources and low costs, a simple recycling process, and can also bring environmental benefits. At present, the price of 2N crude arsenic on the market ranges from about 30 to 200 yuan / kg, while oxygen-containing crude arsenic is difficult to be directly used as a single arsenic substance due to its high oxygen content. The current price is only 10 to 20 yuan / kg, which has significant cost advantages and broad application prospects for the reduction and recycling of oxygen-containing crude arsenic.

[0031] Exemplarily, the purity of the oxygen-containing crude arsenic is not less than 1N grade; exemplary, the purity grade of the oxygen-containing crude arsenic can be 1N~3N grade.

[0032] In the present invention, the oxygen content of the oxygen-containing crude arsenic is not less than 5%; in some embodiments, the oxygen content of the oxygen-containing crude arsenic may be 5-10%.

[0033] It should be noted that the purity of oxygen-containing crude arsenic is obtained by ICP full-element determination of impurity content, excluding oxygen content; the oxygen content is listed separately through oxygen content analyzer testing.

[0034] As another example, the oxygen-containing crude arsenic can be obtained by crushing, and the particle size of the oxygen-containing crude arsenic can be 200-400 mesh. For example, the initial particle size of the oxygen-containing crude arsenic is 0.5-3 cm; the oxygen-containing crude arsenic is sieved after the crushing, and the particle size after the sieving is 200-400 mesh.

[0035] The utilization of oxygenated crude arsenic has important environmental significance. Arsenic is a toxic heavy metal element. If it is discharged directly into the environment without treatment, it will cause serious damage to the soil, water sources and ecosystems. Secondly, the reuse of oxygenated crude arsenic helps to reduce the exploitation of natural resources, promotes the recycling of resources, and is in line with the concept of sustainable development. In addition, by converting oxygenated crude arsenic into valuable metal arsenide products, it can bring economic benefits to related companies and also promote the development and application of environmental protection technologies.

[0036] In the embodiments and comparative examples of the present invention, the purity of the metal material is not less than 3N grade.

[0037] As another example, the particle size of the metal material may be 200-400 mesh.

[0038] In some specific embodiments, the oxygen-containing crude arsenic and the metal material can be placed in an inert atmosphere in proportion, and fully ground and mixed in a mixer to obtain an arsenic metal mixture.

[0039] 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.

[0040] S2, placing the arsenic metal mixture in a vacuum container, heating the vacuum container to 750-950° C. for melting reaction to obtain metal arsenide; the vacuum degree in the vacuum container is 0.001-1 Pa.

[0041] In the present invention, the temperature of the melt reaction can 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, the doping of other impurity elements (such as oxygen elements) is reduced, so 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, too low a temperature (<750°C) has low reaction efficiency, and it is difficult to prepare high-quality zinc arsenide products without a phase change effect; while too high a temperature (>950°C) has 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 impurities is large, the volatilization rate is fast, and it is difficult to fully reduce. In addition, too high a temperature also poses challenges to the selection of heating equipment materials, so it is not the preferred temperature range for industrialization; the present invention sets the upper limit of the melting reaction temperature to 950°C, and the ideal temperature is around 800°C, which can effectively avoid the formation of arsenic oxide derived from residual oxygen in the oxygen-containing crude arsenic, and is conducive to the preparation of high-quality zinc arsenide products, so that the oxygen content of the final arsenide product is <1%.

[0042] 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 used 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.

[0043] Exemplarily, the temperature of the melt reaction can be controlled at 770-830°C or 800-950°C; and further exemplary, the temperature of the melt reaction can be controlled at 780-820°C.

[0044] In the present invention, a reducing agent can be added to the arsenic metal mixture before or during the melting reaction to control the reducing agent to participate in the melting reaction; specifically, the reducing agent can be added to the arsenic metal mixture before the melting reaction; for example, the reducing agent and the arsenic metal mixture are mixed and placed together in the vacuum container to carry out the melting reaction.

[0045] In some embodiments of the present invention, 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.

[0046] In some specific embodiments of the present invention, the reducing agent may include activated carbon and / or graphite powder.

[0047] In the present invention, the duration of the melting reaction may be 5 to 12 hours; illustratively, the duration of the melting reaction may be 6 to 10 hours, and further may be 6 to 8 hours.

[0048] In some embodiments, the vacuum degree of the vacuum container can be 0.001-0.01 Pa to further reduce the oxygen content and improve the product purity.

[0049] It should be understood that a high vacuum environment can effectively inhibit the occurrence of oxidation reactions, prevent oxygen and water vapor from reacting with arsenic, and thus reduce the generation of oxidation by-products. In addition, the melting point of metal arsenides can be significantly reduced in a high vacuum environment with extremely low pressure, further improving the uniformity and purity of metal arsenides. High vacuum can also promote the efficient evaporation and deposition process of metal arsenides by reducing the impact of impurities in the air, and improve the efficiency of converting arsenic sources into arsenic electronic special gases. When external reducing agents enter the reaction system, they can react with oxygen in the oxide to effectively remove oxygen from the metal arsenide, thereby further purifying the metal arsenide.

[0050] In some specific embodiments, the arsenic metal mixture can be added into a vacuum container, which is sealed and evacuated and then placed into a furnace. The temperature is set at 750-950° C., and the mixture is melted for more than 5 hours and then cooled to obtain a metal arsenide block.

[0051] 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 granular product. Specifically: in step S2, 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 granular product; the particle size of the metal arsenide granular product can be 0.6~8mm.

[0052] 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.

[0053] Also illustratively, the inert atmosphere includes one of nitrogen or argon.

[0054] The present invention also provides an application of a metal arsenide prepared by the method for preparing a metal arsenide as described in any one of the above in the production of arsenic electronic specialty gases.

[0055] Arsenic electronic special gases are an important class of semiconductor electronic gases used in the chemical vapor deposition (CVD) process to grow gallium arsenide (GaAs) and other arsenic-based compound semiconductor materials. Metallic arsenide, as a potential arsenic source, can be converted into arsenic electronic special gases through a controllable chemical process, and reducing impurities in the preparation process can effectively improve the purity of arsenic electronic special gases.

[0056] For further understanding of the present invention, examples are given below: Example 1 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 through a mixer, and add the arsenic metal mixture into a vacuum container.

[0057] 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.

[0058] 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, the metal arsenide particle product that meets the requirements is obtained. In terms of mass fraction, the oxygen content in the metal arsenide is 0.53%, the antimony content is 0.04%, the total content of arsenic + zinc is >99%, the product purity reaches 99.9%, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0059] Example 2 Compared with Example 1, only the melting reaction temperature in step 2 is changed: 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 through a mixer, and add the arsenic metal mixture into a vacuum container.

[0060] 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.

[0061] 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.

[0062] Calculated by mass fraction, the oxygen content in the metal arsenide is 0.49%, the antimony content is 0.07%, and the total content of arsenic + zinc is >99%.

[0063] Example 3 Compared with Example 1, only the melting reaction temperature in step 2 is changed: 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 through a mixer, and add the arsenic metal mixture into a vacuum container.

[0064] 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 820°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0065] 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.

[0066] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.67%, the antimony content is 0.03%, and the total content of arsenic + zinc is >99%.

[0067] Example 4 Compared with Example 1, only the melting reaction temperature in step 2 is changed: 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.

[0068] 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.

[0069] 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.

[0070] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.98%, the antimony content is 0.48%, and the total content of arsenic + zinc is >99%.

[0071] Example 5 Compared with Example 1, only the ratio of arsenic and metal materials in step 1 is changed: 1. First, place 100g of oxygen-containing crude arsenic and 150g 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.

[0072] 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.

[0073] 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 single active metal.

[0074] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.51%, the antimony content is 0.07%, and the total content of arsenic + zinc is >99%.

[0075] Example 6 Compared with Example 1, only the ratio of arsenic and metal materials in step 1 is changed: 1. First, place 100g of oxygen-containing crude arsenic and 170g 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.

[0076] 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.

[0077] 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%, the crystal structure conforms to the standard Zn3As2 card configuration, and only contains a certain amount of single active metal.

[0078] Calculated by mass fraction, the oxygen content in the metal arsenide is 0.34%, the antimony content is 0.09%, and the total content of arsenic + zinc is >99%.

[0079] Example 7 Compared with Example 1, only the vacuum conditions in step 2 are changed: 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.

[0080] 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, and the crystal structure conforms to the standard Zn3As2 card configuration.

[0081] 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%.

[0082] Calculated by mass fraction, the oxygen content of the metal arsenide is 0.67%, the antimony content is 0.23%, and the total content of arsenic + zinc is >99%.

[0083] Example 8 Compared with Example 1, only the type of active metal material in step 1 is changed: 1. First, place 100g of oxygen-containing crude arsenic and 130g 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 them thoroughly with a mixer, and add the mixture into a vacuum container.

[0084] 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.

[0085] 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%.

[0086] 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%.

[0087] Example 9 Compared with Example 1, only the type of active metal material in step 1 is changed: 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.

[0088] 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.

[0089] 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%.

[0090] Calculated by 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 elements is >99%.

[0091] Example 10 Compared with Example 1, only the type of reducing agent in step 1 is changed: 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.

[0092] 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.

[0093] 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%.

[0094] 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%.

[0095] Embodiment 11 Compared with Example 1, only the type of reducing agent in step 1 is changed: 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.

[0096] 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.

[0097] 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%.

[0098] 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%.

[0099] Comparative Example 1 Compared with Example 1, only the melting temperature in step 2 is changed: 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] Comparative Example 2 Compared with Comparative Example 1, only the vacuum conditions in step 2 were changed: 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.

[0104] 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.

[0105] Comparative Example 3 Compared with Example 1, the reaction time and vacuum conditions in step 2 are changed: 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.

[0106] 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.

[0107] Comparative Example 4 Compared with Example 1, only the reaction time in step 2 was changed: 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.

[0108] 2. The vacuum container containing the arsenic metal mixture was evacuated to a vacuum degree of 0.001 Pa and then sealed. The sealed vacuum container was placed in a high-temperature furnace for a melting reaction. The reaction temperature was set at 800°C and the reaction time was 4 hours. The melting reaction was too short and the final product was not completely reacted and presented a separate two-phase structure of elemental arsenic and zinc. Therefore, the metal arsenide block after the reaction was not obtained.

[0109] Comparative Example 5 Compared with Example 1, only the vacuum conditions in step 2 are changed: 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.

[0110] 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.

[0111] 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 with a product purity of 99% and an oxygen content of 2.62%.

[0112] Comparative Example 6 Compared with Example 1, only the vacuum conditions in step 2 are changed: 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.

[0113] 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 the vacuum condition is not 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.

[0114] 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. The final metal arsenide / arsenic oxide mixed particles have an oxygen content of 6.01%, which does not meet the requirements.

[0115] Comparative Example 7 Compared with Example 1, only the ratio of arsenic and metal materials in step 1 is changed: 1. First, place 100g of oxygen-containing crude arsenic and 100g 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.

[0116] 2. Evacuate the vacuum container with the mixed material 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 6 hours. After the melting reaction, cool it to obtain a metal arsenide block. Due to insufficient active metal content in the raw materials, 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.

[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 mesh size to 6 to finally obtain a mixed particle product of Zn3As2 and ZnAs2. In terms of mass fraction, the oxygen content in the metal arsenide is 0.55%, the antimony content is 0.26%, and the total content of arsenic + zinc is >99%.

[0118] Comparative Example 8 Compared with Example 1, only the melting temperature in step 2 is changed: 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.

[0119] 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.

[0120] 3. Take out the metal arsenide block under an inert atmosphere, crush it with a ball mill and then sieve it. Set the ball milling time to 6 hours and the mesh size to 6. Finally, obtain the metal arsenide particle product that meets the requirements. The product purity reaches 99% and the crystal structure conforms to the standard Zn3As2 card configuration (that is, compare the measured XRD peak with the standard PDF card to compare the main peak, secondary main peak and other positions highly overlapped).

[0121] Calculated by mass fraction, the oxygen content in the metal arsenide is 2.90%, the antimony content is 0.37%, and the total content of arsenic + zinc is >95%.

[0122] Comparative Example 9 Compared with Example 1, only the melting temperature in step 2 is changed: 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.

[0123] 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 1050°C and the reaction time to 6h. After the melting reaction is completed, cool it to obtain a metal arsenide block.

[0124] 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, a metal arsenide particle product is obtained with a product purity of 99%.

[0125] In terms of mass fraction, the oxygen content of the metal arsenide is 4.19%, the antimony content is 0.31%, and the total content of arsenic + zinc is >95%. However, due to the high temperature, the vapor pressure of arsenic oxide increases significantly, the volatilization of arsenic oxide intensifies, and it evaporates directly from the reaction system without the reduction process, resulting in an increase in the oxygen content in the product, which has an adverse effect on the gas production of the subsequent gaseous arsenide preparation process.

[0126] Analysis example 1 Characterization and analysis of the oxygen-containing crude arsenic used in Examples 1 to 11 and Comparative Examples 1 to 9: 1. Perform elemental quantitative analysis on the oxygen-containing crude arsenic. The analysis results are as follows: Figure 2 As shown. Figure 2 It can be observed that the Sb content is as high as 1326.2ppm, which is the impurity element with the highest content. Other impurity elements include Si, S, B, etc., with concentrations of 52.3ppm, 4.6ppm, and 1.5ppm respectively. In addition, the oxygen content is as high as 7.4%. The purity of the oxygen-containing crude arsenic sample was analyzed, and it was 2N grade oxygen-containing crude arsenic.

[0127] 2. The oxygen-containing crude arsenic was subjected to SEM morphology analysis. The analysis results are as follows: Figure 3 As shown, Figure 3 (a) is the SEM image of oxygen-containing crude arsenic at a scale of 20 microns. Figure 3 (b) is the SEM image of oxygen-containing crude arsenic at a scale of 1 micron. It is found that the oxygen-containing crude arsenic is mainly fine particles of micron size after crushing. High-magnification morphological observation of the oxygen-containing crude arsenic reveals that it is mainly an octahedral structure.

[0128] 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 a metal arsenide, characterized in that: include: Mixing oxygen-containing crude arsenic and a metal material 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 arsenic metal mixture is placed in a sealed vacuum container, and the vacuum container is heated to 750-950° C. for 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.

2. The method for preparing metal arsenide according to claim 1, characterized in that: The metal material includes active metal powder; the metal material includes one of magnesium material, zinc material and aluminum material.

3. 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.

4. The method for preparing metal arsenide according to claim 3, 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.

5. The method for preparing metal arsenide according to claim 1, characterized in that: The duration of the melting reaction is 5 to 12 hours; the purity of the oxygen-containing crude arsenic is 1N to 3N; and the oxygen content of the oxygen-containing crude arsenic is not less than 5%.

6. 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.

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

8. 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.

9. 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.

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

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