Method and device for catalytic cracking of gaseous arsenide

Abstract

The present invention provides a method and apparatus for catalytic cracking of gaseous arsenide, comprising the following steps: After catalytically cracking the gaseous arsenide through a catalyst, it is condensed and collected, and the condensate formed by condensation is high-purity arsenic. The temperature of the catalytic cracking is 100 °C to 300 °C; the gaseous arsenide is arsine gas; the catalyst is one of the oxides corresponding to transition metals / noble metals. The total impurity content of the high-purity arsenic is <0.1 ppm. The duration of the catalytic cracking is 1 to 2 h. In a closed protective gas environment, the high-purity arsenic is encapsulated to avoid contamination by oxygen and water in the air. By means of catalytically cracking gaseous arsenide, a new process for preparing high-purity arsenic is developed, which reduces the production difficulty and can prepare high-purity arsenic products with high yield and purity. Among them, the purity of the high-purity arsenic product reaches 7N or higher grade.

Description

Technical Field

[0001] The present invention relates to the field of high-purity metal preparation, and particularly to a method and device for catalytic cracking of gaseous arsenides. Background Art

[0002] As an important basic raw material in semiconductors and electronic materials, high-purity arsenic is mainly used to prepare arsenide semiconductors such as gallium arsenide (GaAs) and indium arsenide (InAs). These materials play an irreplaceable role in high-frequency applications such as integrated circuits and optical communications. The high mobility and unique electronic properties of high-purity arsenic have made it highly regarded in the fields of microelectronics and optoelectronics. However, the preparation of high-purity arsenic faces problems such as difficult impurity control and easy contamination during storage, which directly affect the quality and performance of semiconductor devices.

[0003] Currently, the preparation of high-purity arsenic mainly includes the chlorination method and the distillation method. In the chlorination method, arsenic reacts with chlorine to form arsenic chloride, which is then reduced to obtain arsenic. However, this method has significant problems. In particular, the chlorides generated during the reaction often carry a large amount of metal impurities, and the equipment is prone to corrosion during the chlorination process, increasing the complexity of operation. The distillation method is another commonly used preparation method, which purifies arsenic by distillation. However, the disadvantage of the distillation method is that its operating temperature is relatively high, and due to the difficulty in controlling the temperature, it is prone to equipment damage, pollutant residues, and energy waste, thus limiting its application in the preparation of high-purity arsenic.

[0004] Although high-temperature pyrolysis can decompose arsine and release high-purity arsenic, in practical applications, incomplete decomposition occurs during the high-temperature pyrolysis process. The yield of arsine converted to high-purity arsenic is low, and the high-temperature by-products generated are difficult to remove, introducing new impurities and ultimately affecting the purity of the product. Based on this, it is necessary to provide a method and device for catalytic cracking of gaseous arsenides under low-temperature conditions to alleviate or solve the above problems. Summary of the Invention

[0005] The main object of the present invention is to provide a method and device for catalytic cracking of gaseous arsenides to solve the technical problems of impurity residues in the preparation process affecting purity and low yield of high-purity arsenic due to high-temperature pyrolysis.

[0006] To achieve the above object, the present invention provides a method for catalytic cracking of gaseous arsenides, including the following steps:

[0007] After catalytic cracking of the gaseous arsenide through a catalyst, it is condensed and collected. The condensate formed is high-purity arsenic. The temperature of the catalytic cracking is 100 °C to 300 °C; the gaseous arsenide is arsine gas; the catalyst is one of the oxides corresponding to transition metals / noble metals.

[0008] According to an embodiment of the present application, the transition metal includes cobalt, nickel, copper or manganese; the noble metal includes gold, silver or platinum.

[0009] According to an embodiment of the present application, the temperature of the catalytic cracking is 120 °C to 250 °C; the duration of the catalytic cracking is 1 to 2 h.

[0010] According to an embodiment of the present application, the temperature of the condensation is 50 to 150 °C lower than the temperature of the catalytic cracking; the duration of the condensation is 1 to 2 h.

[0011] According to an embodiment of the present application, the gaseous arsenide gas is catalytically cracked under a slightly positive pressure condition, and the pressure of the slightly positive pressure is 0.001 to 0.02 MPa.

[0012] According to an embodiment of the present application, in the step of catalytically cracking the gaseous arsenide through a catalyst, the gaseous arsenide flows in the form of an air flow bundle and is heated along the flow path.

[0013] According to an embodiment of the present application, the flow rate of the gaseous arsenide flowing in the form of an air flow bundle is 1 to 2 L / min / cm 2 。

[0014] According to an embodiment of the present application, the addition amount of the catalyst is 5% to 10% of the mass of the gaseous arsenide gas.

[0015] According to an embodiment of the present application, the high-purity arsenic is encapsulated in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0016] The present invention also provides a device for catalytic cracking of gaseous arsenide, including:

[0017] The catalytic cracking device includes a heater, a condenser and a collector with adjustable temperature.

[0018] The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein, the temperature of the catalytic cracking is 100 °C to 300 °C; the duration of the catalytic cracking is 1 to 2 h.

[0019] The condenser is connected to the heater and is used to condense the arsine pyrolyzate in the pyrolysis gas to form condensate; the duration of the condensation is 1 to 2 h.

[0020] The collector is connected to the condensation outlet of the condenser and is used to collect the condensate.

[0021] The recycler is connected to the gas phase outlet of the condenser and is used to collect the gas phase material.

[0022] Beneficial effects:

[0023] In the above method for catalytic cracking of gaseous arsenide, after the gaseous arsenide is catalytically cracked by a catalyst, it is then condensed and collected. The condensate formed by condensation is high-purity arsenic. The temperature of the catalytic cracking is 100 °C to 300 °C; by introducing a catalyst, the decomposition reaction of arsine can be achieved at a lower temperature. Low-temperature catalytic pyrolysis can not only effectively reduce the energy consumption and equipment pressure of the reaction, but also significantly improve the selectivity of the reaction. In addition, the introduction of the catalyst avoids the common problem of impurity residues in high-temperature pyrolysis, thereby effectively improving the purity and yield of high-purity arsenic. Therefore, the low-temperature pyrolysis technology provides a more efficient, economical and environmentally friendly way for the preparation of high-purity arsenic, especially suitable for meeting the strict purity requirements of the semiconductor industry for arsenic sources. Moreover, the method for catalytic cracking of gaseous arsenide provided by the present invention has a simple process and is convenient to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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 the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the structures shown in these drawings.

[0025] Figure 1 It is a schematic diagram of the operation process for Examples 1 to 8.

[0026] The realization, functional features and advantages of the object of the present invention will be further described in conjunction with the embodiments with reference to the drawings. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0028] In addition, in the present invention, descriptions such as "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features.

[0029] Moreover, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those skilled 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 scope of protection required by the present invention.

[0030] To achieve the above object, the present invention provides a method for catalytic cracking of gaseous arsenide, comprising the following steps:

[0031] After catalytic cracking of the gaseous arsenide through a catalyst, it is then condensed and collected. The condensate formed by condensation is high-purity arsenic. The temperature of the catalytic cracking is 100 °C to 300 °C; the gaseous arsenide is arsine gas.

[0032] After catalytic cracking of the gaseous arsenide through a catalyst, arsine is pyrolyzed into gaseous high-purity arsenic. Through condensation, the gaseous high-purity arsenic is converted into solid high-purity arsenic and separated from other gaseous substances (such as unreacted gaseous arsenide, hydrogen generated by catalytic cracking, and trace impurities that may exist in the gaseous arsenide). Among them, the total impurity content of the high-purity arsenic is <0.1 ppm.

[0033] In some embodiments, after catalytic cracking and condensation of the gaseous arsenide through a catalyst, it can be used to remove impurities such as hydrogen.

[0034] Due to its special electronic structure and surface activity, the catalyst can effectively promote the cracking of arsine. These catalysts form coordination bonds with arsine to lower the energy barrier of the reaction, increase the reaction rate, thereby obtaining high-purity arsenic, effectively reducing the reaction temperature, and increasing the pyrolysis rate of arsine.

[0035] In some embodiments, the catalyst is one of the oxides corresponding to transition metals / noble metals.

[0036] In some embodiments, the transition metals include cobalt, nickel, copper or manganese; the noble metals include gold, silver or platinum.

[0037] In some specific embodiments, the catalyst is selected from copper oxide, silver oxide or nickel oxide. In particular, the preferred catalyst is copper oxide, which shows good results in the process of catalytic cracking of arsine into high-purity arsenic, mainly due to its unique ability to regulate electronic states. The surface of copper oxide contains Cu 2+ and Cu + two different chemical electronic states. Cu 2+ can participate in the reaction as an oxidation source to promote the dehydrogenation reaction of arsine to generate high-purity arsenic; while Cu +Reductive copper helps to promote the release of elemental arsenic and reduce the formation of by-products. Similarly, silver oxide and nickel oxide surfaces have similar electron transfer capabilities, which can promote the adsorption and dehydrogenation of arsine and finally catalytically crack arsine into elemental arsenic. In summary, the dynamic regulation of electrons on the surfaces of these metal catalysts makes the reaction have good selectivity and high efficiency, thus significantly improving the yield of converting arsine into high-purity arsenic and ensuring that the final product is high-purity arsenic.

[0038] In some embodiments, the catalytic cracking of arsine is achieved by adding an external catalyst, which can significantly reduce the activation energy and reaction temperature of the cracking reaction, thereby accelerating the decomposition of macromolecular compounds such as arsine gas into gaseous arsenic and hydrogen, promoting the decomposition of arsine at a lower temperature, and thus preparing high-purity arsenic.

[0039] In addition, the introduction of the catalyst avoids the common problem of impurity residues in high-temperature pyrolysis, thereby effectively improving the purity and yield of high-purity arsenic. It should be noted that both pyrolysis and catalytic cracking refer to the destruction of the gaseous molecular bonds of arsine to achieve the pyrolysis of arsine into gaseous high-purity arsenic, and then the gaseous high-purity arsenic is condensed into solid high-purity arsenic by a condenser.

[0040] In some embodiments, the temperature of catalytic cracking is 120 °C to 250 °C; the duration of catalytic cracking is 1 to 2 h.

[0041] In some embodiments, the temperature of condensation is 50 to 150 °C lower than the temperature of the catalytic cracking; the duration of condensation is 1 to 2 h.

[0042] In some specific embodiments, the temperature of the catalytic cracking is 200 °C, the temperature of condensation is 100 °C, and the duration of both catalytic cracking and condensation is 1 h. Among them, the heating duration needs to be controlled. If the heating duration is too short, the impurities will not be completely removed; if the heating duration is too long, the preparation efficiency of high-purity arsenic will be affected.

[0043] In some embodiments, the catalytic cracking of the gaseous arsenide gas is carried out under a slightly positive pressure condition, and the pressure of the slightly positive pressure is 0.001 to 0.02 MPa. By catalytically cracking arsine to prepare high-purity arsenic under a slightly positive pressure condition, the continuous progress of the catalytic conversion process can be effectively maintained, preventing the arsine gas from rapidly escaping to the condensation outlet due to excessive pressure.

[0044] In some embodiments, in the step of catalytically cracking the gaseous arsenide through a catalyst, the arsine flows in the form of an air flow bundle and is heated along the flow path.

[0045] In some embodiments, in the steps of catalytic cracking and condensation, pipelines with different pipe diameters and pipe lengths are included, which can direct the flow of arsine gas and control the pyrolysis rate. Arsine flows in the corresponding pipeline, that is, it flows in the form of an air flow bundle along the corresponding flow path.

[0046] In some embodiments, the pipe diameter is 2 - 6 cm and the pipe length is 8 - 12 cm. With the mutual cooperation of the pipe diameter and the pipe length, the control of the gaseous molecular gas flow is realized, and the pyrolysis of arsine into gaseous high-purity arsenic is achieved.

[0047] In some embodiments, the flow rate of the arsine flowing in the form of a gas flow beam is 1 - 2 L / min / cm 2 。

[0048] In some embodiments, the addition amount of the catalyst is 0.005% - 0.01% g / L of the arsine gas flow rate.

[0049] In some embodiments, the addition amount of the catalyst is 5 - 10% of the mass of the gaseous arsenide. When the gaseous arsenide is added in the form of a gas flow beam, correspondingly, the addition amount of the gaseous arsenide remains unchanged, and the catalyst is added in the manner of 0.005% - 0.01% g / L of the arsine gas flow rate. For example, when the arsine gas flow rate is 1 L, the corresponding addition amount of the catalyst is 0.005% - 0.01% g.

[0050] In some embodiments, the high-purity arsenic is encapsulated in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0051] In some embodiments, the enclosure is achieved through a sealing interface. The sealing interface methods include a face seal (VCR) joint connected to a ball valve, VCR connected to VCR, and VCR connected to a ferrule; among them, the sealing interface method is not specifically limited, as long as the connection tightness and reliability can be ensured.

[0052] In some embodiments, in the closed protective gas environment, the high-purity arsenic is transferred to a glove box and encapsulated with an electronic-grade packaging bag to ensure that the high-purity arsenic is not contaminated by oxygen and moisture in the outside air during the transfer and encapsulation processes, thereby further reducing the impurity content and ensuring the stability of the product quality.

[0053] For the above method for catalytic cracking of gaseous arsenide, after the gaseous arsenide is catalytically cracked by a catalyst, it is then condensed and collected, and the condensate formed by condensation is high-purity arsenic; the temperature of the catalytic cracking is 100 °C - 300 °C; the gaseous arsenide is arsine gas; the total impurity content of the high-purity arsenic is <0.1 ppm. By using the method of strictly controlling the temperature of the catalytic cracking and utilizing the catalytic action of the catalyst, the catalytic cracking of gaseous arsenide into gaseous high-purity arsenic at low temperature is realized, and after condensation, it is converted into solid high-purity arsenic and collected. Moreover, the method for catalytic cracking of gaseous arsenide provided by the present invention has a simple process, convenient operation, and high purity and yield of the prepared high-purity arsenic product.

[0054] The present invention also provides a device for catalytic cracking of gaseous arsenide, comprising:

[0055] The catalytic cracking device includes a heater, a condenser and a collector, the temperature of which can be regulated.

[0056] The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein, the temperature of the catalytic cracking is 100 °C to 300 °C; the duration of the catalytic cracking is 1 to 2 h.

[0057] In some embodiments, the temperature of the catalytic cracking is 200 °C and the duration of the catalytic cracking is 1 h.

[0058] In some embodiments, the heater can be a pyrolysis tower, which only needs to be able to achieve temperature regulation within a certain range and can return to room temperature after heating stops. The temperature regulation range of the heater is 100 °C to 300 °C. It is used for catalytic pyrolysis of arsine.

[0059] In some embodiments, gaseous arsenide is introduced into the catalytic cracking device, first heated by the heater, in which there is a catalyst. By regulating the temperature, the arsenic-hydrogen bond is broken by pyrolysis, realizing the pyrolysis of arsine into gaseous high-purity arsenic, and then condensed into solid high-purity arsenic by the condenser.

[0060] The condenser is connected to the heater and is used to condense the arsine pyrolyzate in the pyrolysis gas to form condensate; the duration of the condensation is 1 to 2 h.

[0061] The collector is connected to the condensation outlet of the condenser and is used to collect the condensate to obtain the high-purity arsenic.

[0062] The recycler is connected to the gas phase outlet of the condenser and is used to collect the gas phase substances.

[0063] In some embodiments, impurities such as hydrogen and oxygen are collected in the recycler.

[0064] In some embodiments, the collector is used to collect the condensate as solid high-purity arsenic.

[0065] In some embodiments, the heater is hermetically connected to the condenser and the collector in sequence.

[0066] Wherein, the collector is located below the condenser.

[0067] In some embodiments, on the same horizontal plane, from left to right, the heater is hermetically connected to the condenser and the collector in sequence. Wherein, the collector is located below the condenser.

[0068] In some embodiments, the heater is connected to the condenser, the collector and the recycler in sequence.

[0069] Among them, the condenser is connected to the heater.

[0070] The collector is located below the condenser.

[0071] In some embodiments, on the same horizontal plane, from left to right, the heater is connected to the condenser, the collector, and the recycler. Among them, the connection method is a sealed connection.

[0072] In some embodiments, the condenser is connected to the heater; the collector is located below the condenser; the recycler is located above the condenser, and the position of the recycler is not specifically limited, and any position that can achieve the purpose of recycling gas is acceptable.

[0073] In some embodiments, during the process of pyrolyzing arsine in the heater and condensing to obtain solid high-purity arsenic, the total impurity content of the high-purity arsenic is <0.1 ppm; a high-purity arsenic product with a purity of 7N or higher grade is obtained.

[0074] The preparation device for catalytic cracking of gaseous arsenide into high-purity arsenic provided by this application has a simple process, convenient operation, simplifies the preparation process, reduces the production difficulty, realizes the pyrolysis of arsine and the removal of impurities, and obtains a high-purity arsenic product with a purity of 7N or higher grade.

[0075] For a further understanding of the present invention, examples are given below for illustration:

[0076] Among them, the pressure in the pyrolysis device of each example and comparative example is 0.01 MPa. The yield is the actual yield, and the yield = (mass of high-purity arsenic / mass of arsine) × 100%.

[0077] Example 1

[0078] Feed 500 g of arsine into the pyrolysis device, add copper oxide accounting for 5% of the mass of arsine as a catalyst, the temperature of catalytic cracking is 200 °C, and the duration of catalytic cracking is 1 hour.

[0079] Among them, the flow rate of the gas flow in the pyrolysis device (that is, the flow rate of gaseous arsenide flowing in the form of a gas flow bundle, the same below) is 1 L / min / cm 2 .

[0080] Feed the arsine after catalytic cracking by the catalyst into the condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour, obtaining 286.2 g of high-purity arsenic, and the yield is 57.2%.

[0081] Transfer the high-purity arsenic to the glove box under argon airtight protection, and then encapsulate it with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm, and the purity of the high-purity arsenic is >7N.

[0082] Example 2

[0083] Among them, compared with Example 1, Example 2 changed the temperature of catalytic cracking.

[0084] 500 g of arsine was fed into the pyrolysis device, copper oxide accounting for 5% of the mass of arsine was added as a catalyst, the temperature of catalytic cracking was 150 °C, and the duration of catalytic cracking was 1 hour.

[0085] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0086] The arsine after catalytic cracking by the catalyst was fed into the condensation device, the condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 253.7 g of high-purity arsenic, with a yield of 50.7%.

[0087] The high-purity arsenic was transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic was <0.1 ppm, and the purity of the high-purity arsenic was >7N.

[0088] Example 3

[0089] Among them, compared with Example 1, Example 3 changed the temperature of catalytic cracking.

[0090] 500 g of arsine was fed into the pyrolysis device, copper oxide accounting for 5% of the mass of arsine was added as a catalyst, the temperature of catalytic cracking was 250 °C, and the duration of catalytic cracking was 1 hour.

[0091] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0092] The arsine after catalytic cracking by the catalyst was fed into the condensation device, the condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 289.2 g of high-purity arsenic, with a yield of 57.8%.

[0093] The high-purity arsenic was transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic was <0.1 ppm, and the purity of the high-purity arsenic was >7N.

[0094] Example 4

[0095] Among them, compared with Example 1, Example 4 changed the temperature of catalytic cracking.

[0096] 500 g of arsine was fed into the pyrolysis device, copper oxide accounting for 5% of the mass of arsine was added as a catalyst, the temperature of catalytic cracking was 300 °C, and the duration of catalytic cracking was 1 hour.

[0097] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0098] The arsine after catalytic cracking by a catalyst is sent to a condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 291.7 g of high-purity arsenic with a yield of 58.3%.

[0099] The high-purity arsenic is transferred into a glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm and the purity of the high-purity arsenic is >7N.

[0100] Example 5

[0101] Among them, compared with Example 1, Example 5 changes the flow rate of the gas stream.

[0102] 500 g of arsine is sent into a pyrolysis device, adding copper oxide accounting for 5% of the mass of arsine as a catalyst. The catalytic cracking temperature is 200 °C and the catalytic cracking duration is 1 hour.

[0103] The flow rate of the gas stream in the pyrolysis device is 2 L / min / cm 2 。

[0104] The arsine after catalytic cracking by a catalyst is sent to a condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 196.5 g of high-purity arsenic with a yield of 39.3%.

[0105] The high-purity arsenic is transferred into a glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm and the purity of the high-purity arsenic is >7N.

[0106] Example 6

[0107] Among them, compared with Example 1, Example 6 changes the type of catalyst.

[0108] 500 g of arsine is sent into a pyrolysis device, adding silver oxide accounting for 5% of the mass of arsine as a catalyst. The catalytic cracking temperature is 200 °C and the catalytic cracking duration is 1 hour.

[0109] The flow rate of the gas stream in the pyrolysis device is 1 L / min / cm 2 。

[0110] The arsine after catalytic cracking by a catalyst is sent to a condensation device. The condensation temperature is 100 °C and the condensation duration is 1 hour, obtaining 81.5 g of high-purity arsenic with a yield of 16.3%.

[0111] The high-purity arsenic is transferred into a glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic is <0.1 ppm and the purity of the high-purity arsenic is >7N.

[0112] Example 7

[0113] Among them, in Example 7 compared with Example 1, the catalyst type was changed.

[0114] 500 g of arsine was fed into the pyrolysis device, nickel oxide accounting for 5% of the mass of arsine was added as the catalyst, the catalytic pyrolysis temperature was 200 °C, and the catalytic pyrolysis duration was 1 hour.

[0115] where the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0116] The arsine after catalytic pyrolysis by the catalyst was fed into the condensation device, the condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 67.7 g of high-purity arsenic with a yield of 13.5%.

[0117] The high-purity arsenic was transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic was <0.1 ppm, and the purity of the high-purity arsenic was >7N.

[0118] Example 8

[0119] Among them, in Example 8 compared with Example 1, the mass of the catalyst was changed.

[0120] 500 g of arsine was fed into the pyrolysis device, copper oxide accounting for 10% of the mass of arsine was added as the catalyst, the catalytic pyrolysis temperature was 200 °C, and the catalytic pyrolysis duration was 1 hour.

[0121] where the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0122] The arsine after catalytic pyrolysis by the catalyst was fed into the condensation device, the condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 292.7 g of high-purity arsenic with a yield of 58.5%.

[0123] The high-purity arsenic was transferred into the glove box under the airtight protection of argon, and then packaged with an electronic-grade packaging bag. The total impurity content of the high-purity arsenic was <0.1 ppm, and the purity of the high-purity arsenic was >7N.

[0124] Comparative Example 1

[0125] Among them, in Comparative Example 1 compared with Example 1, the catalytic pyrolysis temperature was changed.

[0126] 500 g of arsine was fed into the pyrolysis device, copper oxide accounting for 5% of the mass of arsine was added as the catalyst, the catalytic pyrolysis temperature was 80 °C, and the catalytic pyrolysis duration was 1 hour.

[0127] where the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0128] The arsine after catalytic cracking by the catalyst is sent to a condensation device, the condensation temperature is 30 °C, and the condensation duration is 1 hour to obtain an arsenic product.

[0129] The high-purity arsenic is transferred into a glove box under the protection of argon sealing, and then packaged with an electronic-grade packaging bag.

[0130] However, due to the relatively low temperature of catalytic cracking, only 13.7 g of the final arsenic product is obtained finally, the yield is 2.7%, and the purity is only 5N.

[0131] Comparative Example 2

[0132] Among them, compared with Example 1, Comparative Example 2 omits the step of sending it into the pyrolysis device.

[0133] 500 g of arsine is directly sent to a condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain an arsenic product.

[0134] The arsenic product is transferred into a glove box under the protection of argon sealing, and then packaged with an electronic-grade packaging bag.

[0135] Due to the lack of a pyrolysis device, the arsine is not fully decomposed, and finally only 1.2 g of arsenic product is obtained, the yield is 0.24%, and the purity only reaches 4N level, which cannot meet the application requirements of high-purity arsenic.

[0136] Comparative Example 3

[0137] Among them, compared with Example 1, Comparative Example 3 omits the airtight atmosphere.

[0138] 500 g of arsine is sent into a pyrolysis device, and copper oxide accounting for 5% of the mass of arsine is added as a catalyst. The catalytic cracking temperature is 200 °C, and the catalytic cracking duration is 1 hour.

[0139] The flow rate of the gas flow in the pyrolysis device is 1 L / min / cm 2 .

[0140] The arsine after catalytic cracking by the catalyst is sent to a condensation device, the condensation temperature is 100 °C, and the condensation duration is 1 hour to obtain 279.2 g of high-purity arsenic, and the yield is 55.8%.

[0141] The arsenic product is directly transferred into a glove box, and then packaged with an electronic-grade packaging bag.

[0142] Since it is directly transferred into the glove box without an airtight atmosphere and contacts the external environment and oxygen during the transfer process, the product purity drops to 5N, the oxygen content > 1.5%, and the product quality does not meet the requirements.

[0143] Comparative Example 4

[0144] Among them, in Comparative Example 4, compared with Example 1, the catalyst type was changed.

[0145] 500 g of arsine was fed into the pyrolysis device, and 5% of palladium metal by the mass of arsine was added as a catalyst. The catalytic pyrolysis temperature was 200 °C, and the catalytic pyrolysis duration was 1 hour.

[0146] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0147] The arsine after catalytic pyrolysis by the catalyst was fed into the condensation device. The condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 23.2 g of high-purity arsenic with a yield of 4.6%.

[0148] The high-purity arsenic was transferred into the glove box under the airtight protection of argon gas, and then packaged with an electronic-grade packaging bag.

[0149] Due to the poor catalytic pyrolysis effect of adding the catalyst, the catalytic pyrolysis of gaseous arsenic compounds was incomplete, and only a very small amount of 5N-grade arsenic products were obtained.

[0150] Comparative Example 5

[0151] Among them, in Comparative Example 5, compared with Example 1, the catalyst was omitted.

[0152] 500 g of arsine was fed into the pyrolysis device, and no catalyst was added. The pyrolysis temperature was 200 °C, and the pyrolysis duration was 1 hour.

[0153] Among them, the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 .

[0154] The arsine after pyrolysis was fed into the condensation device. The condensation temperature was 100 °C, and the condensation duration was 1 hour, obtaining 13.9 g of arsenic products with a yield of 2.9%.

[0155] The arsenic products were transferred into the glove box under the airtight protection of argon gas, and then packaged with an electronic-grade packaging bag.

[0156] Due to the omission of the catalyst, the pyrolysis of gaseous arsenic compounds was incomplete, and only a very small amount of 5N-grade arsenic products were obtained.

[0157] Comparative Example 6

[0158] Among them, in Comparative Example 6, compared with Example 1, the catalytic pyrolysis temperature was changed and the catalyst was omitted.

[0159] 500 g of arsine was fed into the pyrolysis device, and no catalyst was added. The pyrolysis temperature was 500 °C, and the pyrolysis duration was 1 hour.

[0160] Among them, the flow rate of the gas flow of the pyrolysis device is 1 L / min / cm 2 .

[0161] The arsine after pyrolysis is sent to a condensation device. The condensation temperature is 400 °C and the condensation duration is 1 hour, obtaining 238.5 g of arsenic product, and the yield is 47.7%.

[0162] The arsenic product is transferred into a glove box under the protection of argon tight seal, and then packaged with an electronic grade packaging bag.

[0163] Since no catalyst is added and the pyrolysis temperature is relatively high, although it can promote the pyrolysis of arsine, it is difficult to synchronously process other thermal impurities that are relatively stable at high temperatures, such as hydrogen sulfide. Finally, only a small amount of 6N grade arsenic product is obtained.

[0164] Among them, Figure 1 is the schematic diagram of the operation process of Examples 1 to 8 of this application. Table 1 shows the corresponding data of the industry-related standards for high-purity arsenic products; Table 2 shows the relevant parameter analysis of the high-purity arsenic prepared in Examples 1 to 8 and the arsenic products prepared in Comparative Examples 1 to 6.

[0165] Table 1 Corresponding data of industry-related standards for high-purity arsenic products

[0166]

[0167] Table 2 Relevant parameter analysis of the high-purity arsenic prepared in Examples 1 to 8 and the arsenic products prepared in Comparative Examples 1 to 6

[0168]

[0169] As shown in Table 1 and Table 2, it can be seen from the results of Examples 1 to 8 that the precise control of the catalytic cracking temperature has a significant impact on the purity of high-purity arsenic. In Example 1, at a catalytic cracking temperature of 200 °C and through a reasonable heating time, the catalytic cracking of arsine into gaseous high-purity arsenic was successfully achieved and converted into solid high-purity arsenic through a condensation device. Especially in Example 2, although the catalytic cracking temperature was reduced to 150 °C, the purity of the high-purity arsenic product could still be maintained, further proving the effectiveness of adding a suitable catalyst and at an appropriate catalytic cracking temperature for the full pyrolysis of arsine, and the purity of the arsine product > 7N. In addition, the type of catalyst has a significant impact on the yield of high-purity arsenic prepared by the catalytic cracking of arsine. Through the comparison of Examples 1, 6, and 7, it was found that when the catalyst was copper oxide and the catalytic cracking temperature was 200 °C, the highest yield of high-purity arsenic was shown, with a yield of 57.2%, which was significantly higher than the yields of high-purity arsenic obtained by the other two metal oxide catalyses, indicating that the selection of the catalyst type is crucial. In Example 8, compared with Example 1, the mass of the catalyst was increased, resulting in a yield of high-purity arsenic of 58.5%, indicating that adding an appropriate mass of catalyst, combined with factors such as the catalytic cracking temperature and the catalyst type, can improve the yield of high-purity arsenic.

[0170] The results of Comparative Examples 1 to 3 showed that when the optimal catalytic pyrolysis temperature could not be controlled, the purity of the arsenic product decreased significantly. In Comparative Example 1, the catalytic cracking temperature was 80 °C, but due to the too low temperature, the pyrolysis of gaseous arsenic compounds was insufficient, and the final product was only of 5N purity. In Comparative Example 4, palladium metal was used as the catalyst, and the catalytic effect was poor, and the full pyrolysis of arsine and the effective removal of impurities could not be achieved, further illustrating the importance of the selection of the catalyst type for the cracking of arsine into high-purity arsenic.

[0171] The results of Comparative Examples 5 to 6 showed that without adding a catalyst, the pyrolysis rate was slow, resulting in incomplete decomposition of arsine and ineffective removal of impurities, and the purity of the final product was low. Especially under the experimental conditions of not adding a catalyst at 200 °C, the pyrolysis reaction was difficult to occur. Even when the catalytic pyrolysis temperature was increased to 500 °C, the product purity also decreased significantly, showing the importance of the selection of the catalyst type and the catalytic pyrolysis temperature in the pyrolysis of gaseous arsenic compounds into high-purity arsenic. From the above-mentioned examples, it can be seen that in Example 1, the catalytic cracking temperature was 200 °C, the condensation temperature was 100 °C, and the flow rate of the gas flow in the pyrolysis device was 1 L / min / cm 2 , high-purity arsenic products could be obtained, with a total impurity content < 0.1 ppm and a high-purity arsenic purity > 7N. This provides a strong basis for further optimizing the preparation process of high-purity arsenic and emphasizes the importance of appropriate temperature control during the pyrolysis process and its impact on impurity removal.

[0172] In the above technical solution of the present invention, the above is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structural transformation 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 to other related technical fields, is included in the patent protection scope of the present invention.

Claims

1. A method for catalytic cracking of gaseous arsenic compounds, characterized in that: The following steps are involved: After the gaseous arsenide is catalytically cracked by a catalyst, it is condensed and collected, and the condensate formed by the condensation is high-purity arsenic, and the temperature of the catalytic cracking is 100°C to 300°C; the gaseous arsenide is arsine gas; and the catalyst is one of the oxides corresponding to the transition metal / noble metal; The transition metal includes cobalt, nickel, copper or manganese; the noble metal includes gold, silver or platinum.

2. The method for catalytic cracking of gaseous arsenic compounds according to claim 1, characterized in that: The temperature of the catalytic cracking is 120°C to 250°C; the duration of the catalytic cracking is 1 to 2 hours.

3. The method for catalytic cracking of gaseous arsenide according to claim 1, characterized in that: The condensation temperature is 50-150° C. lower than the catalytic cracking temperature; the condensation time is 1-2 hours.

4. The method for catalytic cracking of gaseous arsenide according to any one of claims 1 to 3, characterized in that: The gaseous arsenide is catalytically cracked under a slightly positive pressure condition, wherein the pressure of the slightly positive pressure is 0.001-0.02 MPa.

5. The method for catalytic cracking of gaseous arsenic compounds according to claim 1, characterized in that: In the step of catalytically cracking the gaseous arsenic compound through a catalyst, the gaseous arsenic compound flows in a gas stream and is heated along a flow path.

6. The method for catalytic cracking of gaseous arsenic compounds according to claim 5, characterized in that: The gaseous arsenide flows in a stream of air at a flow rate of 1-2 L / min / cm 2 .

7. The method for catalytic cracking of gaseous arsenic compounds according to claim 1, characterized in that: The added amount of the catalyst is 5% to 10% of the mass of the gaseous arsenide gas.

8. The method for catalytic cracking of gaseous arsenic compounds according to claim 1, characterized in that: The high-purity arsenic is packaged in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

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