Gaseous arsenide catalytic cracking method and device

Abstract

The invention provides a gaseous arsenide catalytic cracking method and device, and the method comprises the following steps: carrying out the catalytic cracking of gaseous arsenide through a catalyst, then condensing and collecting the gaseous arsenide, enabling the condensate formed by condensation to be high-purity arsenic, and enabling the catalytic cracking temperature to be 100-300 DEG C; the gaseous arsenide is arsine gas; the catalyst is one of oxides corresponding to transition metal / noble metal. The total content of the high-purity arsenic impurities is 1t; and 0.1 ppm. The catalytic cracking time is 1-2 hours. In a closed protective gas environment, the high-purity arsenic is packaged, so that the pollution of oxygen and water in the air is avoided. By means of catalytic cracking of gaseous arsenide, a novel high-purity arsenic preparation process is developed, the production difficulty is reduced, a high-purity arsenic product with high yield and purity can be prepared, and the purity of the high-purity arsenic product reaches 7N or higher level.

Description

Technical Field

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

[0002] As an important basic raw material for 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 make it highly valued in the fields of microelectronics and optoelectronics. However, the preparation of high-purity arsenic faces the problems of difficult impurity control and easy contamination during storage, which directly affects the quality and performance of semiconductor devices.

[0003] At present, the preparation of high-purity arsenic mainly includes chlorination and distillation. The chlorination method is to generate arsenic chloride by reacting arsenic with chlorine, and then obtain arsenic by reduction. However, this method has major problems, especially the chloride generated during the reaction often contains more metal impurities, and the equipment is prone to corrosion during the chlorination process, which increases the complexity of the operation. Distillation is another commonly used preparation method, which purifies arsenic by distillation. However, the disadvantage of the distillation method is that its operating temperature is high, and due to the difficulty of temperature control, it is easy to cause equipment damage, residual pollutants and energy waste, thereby limiting its application in the preparation of high-purity arsenic.

[0004] Although high-temperature pyrolysis can decompose arsine and release high-purity arsenic, in actual applications, incomplete decomposition occurs during the high-temperature pyrolysis process, the yield of arsine converted into high-purity arsenic is low, and the generated high-temperature byproducts 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 arsenic under low-temperature conditions to alleviate or solve the above problems. Summary of the invention

[0005] The main purpose of the present invention is to provide a method and device for catalytic cracking of gaseous arsenic compounds, so as to solve the technical problems of low yield of high-purity arsenic due to residual impurities in high-temperature pyrolysis affecting purity during the preparation process.

[0006] To achieve the above object, the present invention provides a method for catalytic cracking of gaseous arsenic compounds, comprising the following steps: The gaseous arsenide is catalytically cracked by a catalyst, and then condensed and collected. The condensate formed by the 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 the transition metal / noble metal.

[0007] 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.

[0008] 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 hours.

[0009] According to an embodiment of the present application, the condensation temperature is 50-150° C. lower than the catalytic cracking temperature; and the condensation time is 1-2 hours.

[0010] 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 0.001~0.02 MPa.

[0011] According to an embodiment of the present application, in the step of subjecting the gaseous arsenic compound to catalytic cracking by a catalyst, the gaseous arsenic compound flows in a gas stream and is heated along a flow path.

[0012] According to the embodiment of the present application, the flow rate of the gaseous arsenide flowing in the form of a gas stream is 1-2 L / min / cm 2 .

[0013] According to an embodiment of the present application, the added amount of the catalyst is 5% to 10% of the mass of the gaseous arsenide gas.

[0014] According to an embodiment of the present application, the high-purity arsenic is packaged in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0015] The present invention also provides a device for catalytic cracking of gaseous arsenide, comprising: The catalytic cracking device comprises a heater with adjustable temperature, a condenser and a collector.

[0016] The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein the temperature of the catalytic cracking is 100°C to 300°C; and the duration of the catalytic cracking is 1 to 2 hours.

[0017] The condenser is connected to the heater and is used to condense the arsine pyrolysis product in the pyrolysis gas to form a condensate; the condensation time is 1 to 2 hours.

[0018] The collector is connected to the condensation outlet of the condenser and is used to collect condensate.

[0019] The recovery device is connected to the gas phase outlet of the condenser and is used for collecting the gas phase.

[0020] Beneficial effects: In the above-mentioned method for catalytic cracking of gaseous arsenide, gaseous arsenide is catalytically cracked by a catalyst, and then condensed and collected. The condensate formed by condensation is high-purity arsenic, and the temperature of the catalytic cracking is 100°C~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 of high-purity arsenic and the yield of high-purity arsenic. Therefore, low-temperature pyrolysis technology provides a more efficient, economical and environmentally friendly way for the preparation of high-purity arsenic, which is particularly suitable for meeting the strict purity requirements of the semiconductor industry for arsenic sources. And the method for catalytic cracking of gaseous arsenide provided by the present invention is simple in process and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 This is a schematic diagram of the operation flow of Examples 1 to 8.

[0023] 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

[0024] 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.

[0025] In addition, in the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0026] 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.

[0027] To achieve the above object, the present invention provides a method for catalytic cracking of gaseous arsenic compounds, comprising the following steps: The gaseous arsenide is catalytically cracked by a catalyst, and then condensed and collected. The condensate formed by the condensation is high-purity arsenic. The temperature of the catalytic cracking is 100°C to 300°C. The gaseous arsenide is arsine gas.

[0028] After the gaseous arsenide is catalytically cracked by a catalyst, arsine is pyrolyzed into gaseous high-purity arsenic, and the gaseous high-purity arsenic is converted into solid high-purity arsenic by condensation, and is 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). The total impurity content of the high-purity arsenic is <0.1ppm.

[0029] In some embodiments, the gaseous arsenic compound may be used to remove impurities such as hydrogen after being catalytically cracked and condensed by a catalyst.

[0030] The catalyst can effectively promote the cracking of arsine due to its special electronic structure and surface activity. These catalysts form coordination bonds with arsine to reduce the energy barrier of the reaction and increase the reaction rate, thereby obtaining high-purity arsenic, effectively reducing the reaction temperature and increasing the rate of arsine thermal decomposition.

[0031] In some embodiments, the catalyst is one of the oxides corresponding to transition metals / noble metals.

[0032] In some embodiments, the transition metal comprises cobalt, nickel, copper or manganese; and the noble metal comprises gold, silver or platinum.

[0033] In some specific embodiments, the catalyst is copper oxide, silver oxide or nickel oxide. In particular, copper oxide is preferred as it has shown good results in the process of catalytic cracking of arsine to produce high-purity arsenic, mainly due to its unique electronic state regulation ability. 2+ and Cu + Two different chemical electronic states, Cu 2+ It can participate in the reaction as an oxidation source, promoting the dehydrogenation reaction of arsine to produce high-purity arsenic; and Cu +Reduced copper helps to promote the release of elemental arsenic and reduce the formation of by-products. Similarly, the surfaces of silver oxide and nickel oxide have similar electron transfer capabilities, which can promote the adsorption and dehydrogenation of arsine, and ultimately catalyze the cracking of arsine to produce elemental arsenic. In summary, the dynamic regulation of electrons on the surfaces of these metal catalysts makes the reaction have good selectivity and efficiency, thereby significantly improving the yield of arsine converted to high-purity arsenic and ensuring that the final product is high-purity arsenic.

[0034] In some embodiments, catalytic cracking of arsine can be achieved by adding an external catalyst, which can significantly reduce the activation energy and reaction temperature of the cracking reaction, thereby accelerating the decomposition of macromolecular compounds such as arsine gas into gaseous arsenic and hydrogen, and promoting the decomposition of arsine at a lower temperature, thereby preparing high-purity arsenic.

[0035] In addition, the introduction of the catalyst avoids the common problem of impurity residues in high-temperature pyrolysis, thereby effectively improving the purity and yield of high-purity arsenic. It should be noted that pyrolysis or catalytic cracking refers to the destruction of the gaseous molecular bonds of arsine, achieving the pyrolysis of arsine into gaseous high-purity arsenic, and then condensing it into solid high-purity arsenic through a condenser.

[0036] In some embodiments, the temperature of the catalytic cracking is 120° C. to 250° C.; and the duration of the catalytic cracking is 1 to 2 hours.

[0037] In some embodiments, the condensation temperature is 50-150° C. lower than the catalytic cracking temperature; and the condensation time is 1-2 hours.

[0038] In some specific embodiments, the catalytic cracking temperature is 200° C., the condensing temperature is 100° C., and the catalytic cracking time and the condensing time are both 1 hour. The heating time needs to be controlled. If the heating time is too short, the impurities will not be completely removed. If the heating time is too long, the preparation efficiency of high-purity arsenic will be affected.

[0039] In some embodiments, the gaseous arsenide gas is catalytically cracked under a slightly positive pressure condition, and the pressure of the slightly positive pressure is 0.001-0.02 MPa. By catalytically cracking arsine under a slightly positive pressure condition to prepare high-purity arsenic, the catalytic conversion process can be effectively maintained to prevent the arsine gas from being too high in pressure and quickly escaping to the condensation outlet.

[0040] In some embodiments, in the step of passing the gaseous arsenic compound through a catalyst for catalytic cracking, the arsine flows in a gas stream and is heated along a flow path.

[0041] In some embodiments, the catalytic cracking and condensing steps include pipelines with different diameters and lengths to directional guide the flow of arsine gas and control the pyrolysis rate. Arsine flows in the corresponding pipelines, that is, flows along the corresponding flow paths in the form of gas streams.

[0042] In some embodiments, the tube diameter is 2-6 cm, and the tube length is 8-12 cm. Under the coordination of the tube diameter and the tube length, the gaseous molecular gas flow is controlled, and the arsine is thermally decomposed into gaseous high-purity arsenic.

[0043] In some embodiments, the flow rate of the arsine in the form of a gas stream is 1-2 L / min / cm 2 .

[0044] In some embodiments, the catalyst is added in an amount of 0.005% to 0.01% g / L of the arsine gas flow rate.

[0045] In some embodiments, the amount of catalyst added is 5-10% of the mass of the gaseous arsenide. When the gaseous arsenide is added in a gas stream, the amount of the gaseous arsenide added remains unchanged, and the catalyst is added in a manner of 0.005%-0.01% g / L of the arsine gas flow rate. For example, when the arsine gas flow rate is 1 L, the corresponding amount of catalyst added is 0.005%-0.01% g.

[0046] In some embodiments, the high purity arsenic is packaged in a closed protective gas environment, and the protective gas is nitrogen, helium or argon.

[0047] In some embodiments, the sealing is achieved through a sealed interface. The sealed interface method is a face seal (VCR) joint connected to a ball valve, a VCR connected to a VCR, or a VCR connected to a ferrule; wherein the sealed interface method is not specifically limited, as long as the sealing and reliability of the connection are ensured.

[0048] In some embodiments, in a closed protective gas environment, high-purity arsenic is transferred to a glove box and packaged in electronic-grade packaging bags to ensure that the high-purity arsenic is not contaminated by oxygen and moisture in the outside air during the transfer and packaging process, thereby further reducing the impurity content and ensuring the stability of product quality.

[0049] In the above-mentioned method for catalytic cracking of gaseous arsenide, the gaseous arsenide is catalytically cracked by a catalyst, and 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 <0.1ppm. By strictly controlling the temperature of catalytic cracking, the catalytic effect of the catalyst is utilized to achieve catalytic cracking of gaseous arsenide into gaseous high-purity arsenic at low temperature, which is converted into solid high-purity arsenic after condensation and collected. The method for catalytic cracking of gaseous arsenide provided by the present invention is simple in process, easy to operate, and the prepared high-purity arsenic product has high purity and yield.

[0050] The present invention also provides a device for catalytic cracking of gaseous arsenide, comprising: The catalytic cracking device comprises a heater with adjustable temperature, a condenser and a collector.

[0051] The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein the temperature of the catalytic cracking is 100°C to 300°C; and the duration of the catalytic cracking is 1 to 2 hours.

[0052] In some embodiments, the temperature of the catalytic cracking is 200° C., and the duration of the catalytic cracking is 1 hour.

[0053] In some embodiments, the heater can be a pyrolysis tower, which can heat within the temperature control range and return to room temperature after the heating stops. The heating temperature control range of the heater is 100°C to 300°C. It is used for catalytic pyrolysis of arsine.

[0054] In some embodiments, gaseous arsenide is introduced into a catalytic cracking device, first heated by a heater in which a catalyst is placed, and the temperature is adjusted to break the arsenic hydrogen bonds due to thermal decomposition, thereby achieving thermal decomposition of arsine into gaseous high-purity arsenic, which is then condensed into solid high-purity arsenic through a condenser.

[0055] The condenser is connected to the heater and is used to condense the arsine pyrolysis product in the pyrolysis gas to form a condensate; the condensation time is 1 to 2 hours.

[0056] The collector is connected to the condensation outlet of the condenser and is used to collect condensate to obtain the high-purity arsenic.

[0057] The recovery device is connected to the gas phase outlet of the condenser and is used for collecting the gas phase.

[0058] In some embodiments, impurities such as hydrogen and oxygen are collected in the recycler.

[0059] In some embodiments, the collector is used to collect the condensate as solid high-purity arsenic.

[0060] In some embodiments, the heater is sealedly connected to the condenser and the collector in sequence.

[0061] Wherein, the collector is located below the condenser.

[0062] In some embodiments, on the same horizontal plane, from left to right, the heater is sealedly connected to the condenser and the collector in sequence, wherein the collector is located below the condenser.

[0063] In some embodiments, the heater is connected to the condenser, the collector and the recovery device in sequence.

[0064] Wherein, the condenser is connected to the heater.

[0065] The collector is located below the condenser.

[0066] In some embodiments, on the same horizontal plane, from left to right, the heater is connected to the condenser, the collector and the recovery device, wherein the connection mode is a sealed connection.

[0067] In some embodiments, the condenser is connected to the heater; the collector is located below the condenser; the recovery device is located above the condenser. The position of the recovery device is not specifically limited, and any position that can achieve the purpose of recovering gas can be used.

[0068] In some embodiments, in the heater, during the process of pyrolyzing arsine and condensing to obtain solid high-purity arsenic, the total impurity content of the high-purity arsenic is <0.1 ppm; a high-purity arsenic product with a purity of 7N or higher is obtained.

[0069] The device for preparing high-purity arsenic by catalytic cracking of gaseous arsenic provided in the present application has a simple process, is easy to operate, simplifies the preparation process, reduces the difficulty of production, realizes the thermal decomposition of arsine and the removal of impurities, and obtains a high-purity arsenic product with a purity of 7N or higher.

[0070] For further understanding of the present invention, examples are given below: The pressure in the pyrolysis device of each embodiment and comparative example is 0.01 MPa. The yield is the actual yield, which is the mass of high-purity arsenic divided by the mass of arsine × 100%.

[0071] Example 1 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature of catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0072] The flow rate of the gaseous arsenic compound in the pyrolysis device (i.e., the flow rate of the gaseous arsenic compound in the form of a gas stream, the same below) is 1 L / min / cm 2 .

[0073] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 286.2 g of high-purity arsenic was obtained with a yield of 57.2%.

[0074] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0075] Example 2 Compared with Example 1, Example 2 changes the temperature of catalytic cracking.

[0076] 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of the arsine, was added as a catalyst. The temperature of catalytic cracking was 150° C., and the duration of catalytic cracking was 1 hour.

[0077] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0078] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 253.7 g of high-purity arsenic was obtained with a yield of 50.7%.

[0079] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0080] Example 3 Compared with Example 1, Example 3 changes the temperature of catalytic cracking.

[0081] 500 g of arsine was fed into a pyrolysis device, and copper oxide was added as a catalyst at a rate of 5% by mass of arsine. The temperature of catalytic cracking was 250° C., and the duration of catalytic cracking was 1 hour.

[0082] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0083] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 289.2 g of high-purity arsenic was obtained with a yield of 57.8%.

[0084] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0085] Example 4 Compared with Example 1, Example 4 changes the temperature of catalytic cracking.

[0086] 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature of catalytic cracking was 300° C., and the duration of catalytic cracking was 1 hour.

[0087] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0088] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 291.7 g of high-purity arsenic was obtained with a yield of 58.3%.

[0089] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0090] Example 5 Compared with Example 1, Example 5 changes the flow rate of the airflow.

[0091] 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature of catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0092] The air flow rate of the pyrolysis device is 2L / min / cm 2 .

[0093] Arsine after catalytic cracking by the catalyst was sent to a condensation device at a condensation temperature of 100° C. for 1 hour to obtain 196.5 g of high-purity arsenic with a yield of 39.3%.

[0094] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0095] Example 6 Compared with Example 1, Example 6 changes the catalyst type.

[0096] 500 g of arsine was fed into a pyrolysis device, and silver oxide was added as a catalyst at a rate of 5% by mass of the arsine. The temperature of the catalytic cracking was 200° C., and the duration of the catalytic cracking was 1 hour.

[0097] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0098] Arsine after catalytic cracking by the catalyst was sent to a condensation device at a condensation temperature of 100° C. for 1 hour to obtain 81.5 g of high-purity arsenic with a yield of 16.3%.

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

[0100] Example 7 In which, compared with Example 1, Example 7 changes the catalyst type.

[0101] 500 g of arsine was fed into a pyrolysis device, and nickel oxide was added as a catalyst at a weight ratio of 5% of the mass of arsine. The temperature of catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0102] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0103] Arsine after catalytic cracking by the catalyst was sent to a condensation device at a condensation temperature of 100° C. for 1 hour to obtain 67.7 g of high-purity arsenic with a yield of 13.5%.

[0104] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0105] Example 8 Compared with Example 1, Example 8 changes the mass of the catalyst.

[0106] 500 g of arsine was fed into a pyrolysis device, and copper oxide was added as a catalyst at a concentration of 10% by mass of arsine. The temperature of catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0107] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0108] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100°C and the condensation time was 1 hour. 292.7 g of high-purity arsenic was obtained with a yield of 58.5%.

[0109] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag. The total impurity content of the high-purity arsenic is <0.1ppm, and the purity of the high-purity arsenic is >7N.

[0110] Comparative Example 1 Compared with Example 1, the temperature of catalytic cracking was changed in Comparative Example 1.

[0111] 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of the arsine, was added as a catalyst. The temperature for catalytic cracking was 80° C., and the duration of catalytic cracking was 1 hour.

[0112] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0113] The arsine after catalytic cracking by the catalyst is sent to a condensation device, the condensation temperature is 30° C., the condensation time is 1 hour, and the arsenic product is obtained.

[0114] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0115] However, due to the low temperature of catalytic cracking, only 13.7 g of final arsenic product was obtained, with a yield of 2.7% and a purity of only 5N.

[0116] Comparative Example 2 Compared with Example 1, in Comparative Example 2, the step of feeding into the pyrolysis device is omitted.

[0117] 500 g of arsine was directly fed into a condensation device at a condensation temperature of 100° C. for 1 hour to obtain an arsenic product.

[0118] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0119] Due to the lack of a pyrolysis device, arsine was not fully decomposed, and only 1.2 g of arsenic product was obtained in the end, with a yield of 0.24%. The purity only reached 4N level, which could not meet the application requirements of high-purity arsenic.

[0120] Comparative Example 3 Compared with Example 1, in Comparative Example 3, the enclosed atmosphere is omitted.

[0121] 500 g of arsine was fed into a pyrolysis device, and copper oxide, which was 5% by weight of arsine, was added as a catalyst. The temperature of catalytic cracking was 200° C., and the duration of catalytic cracking was 1 hour.

[0122] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0123] The arsine after catalytic cracking by the catalyst was sent to a condensation device. The condensation temperature was 100° C. and the condensation time was 1 hour. 279.2 g of high-purity arsenic was obtained with a yield of 55.8%.

[0124] The arsenic product was directly transferred into a glove box and then packaged in an electronic grade packaging bag.

[0125] Since the product was not directly transferred to the glove box in a closed atmosphere, it came into contact with the external environment and oxygen during the transfer process, causing the product purity to drop to 5N, the oxygen content >1.5%, and the product quality did not meet the requirements.

[0126] Comparative Example 4 In which, compared with Example 1, the catalyst type was changed in Comparative Example 4.

[0127] 500 g of arsine was fed into a pyrolysis device, and metal palladium was added as a catalyst at a rate of 5% by mass of the arsine. The temperature of the catalytic cracking was 200° C., and the duration of the catalytic cracking was 1 hour.

[0128] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0129] Arsine after catalytic cracking by the catalyst was sent to a condensation device at a condensation temperature of 100° C. and a condensation time of 1 hour to obtain 23.2 g of high-purity arsenic with a yield of 4.6%.

[0130] The high-purity arsenic is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0131] Due to the poor catalytic pyrolysis effect of the added catalyst, the catalytic pyrolysis of the gaseous arsenic compound is incomplete, and only a very small amount of 5N grade arsenic product is obtained.

[0132] Comparative Example 5 Compared with Example 1, the catalyst was omitted in Comparative Example 5.

[0133] 500 g of arsine was fed into a pyrolysis device without adding a catalyst. The cracking temperature was 200° C. and the cracking time was 1 hour.

[0134] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0135] The cracked arsine was sent to a condensation device at a condensation temperature of 100° C. for 1 hour to obtain 13.9 g of arsenic product with a yield of 2.9%.

[0136] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0137] Since no catalyst was added, the thermal decomposition of the gaseous arsenic compound was incomplete, and only a very small amount of 5N grade arsenic product was obtained.

[0138] Comparative Example 6 Compared with Example 1, in Comparative Example 6, the temperature of catalytic cracking was changed and the catalyst was omitted.

[0139] 500 g of arsine was fed into a pyrolysis device without adding a catalyst. The cracking temperature was 500° C. and the cracking time was 1 hour.

[0140] The air flow rate of the pyrolysis device is 1L / min / cm 2 .

[0141] The cracked arsine was sent to a condensation device at a condensation temperature of 400°C and a condensation time of 1 hour to obtain 238.5 g of arsenic product with a yield of 47.7%.

[0142] The arsenic product is transferred into a glove box under argon gas sealing protection, and then packaged in an electronic grade packaging bag.

[0143] Since no catalyst is added and the cracking temperature is relatively high, although the thermal decomposition of arsine can be promoted, it is difficult to simultaneously treat other thermal impurities that are relatively stable at high temperatures, such as hydrogen sulfide, and ultimately only a small amount of 6N grade arsenic product is obtained.

[0144] in, Figure 1 The schematic diagram of the operation flow of Examples 1 to 8 of the present application. Table 1 is the corresponding data of the industry-related standards of high-purity arsenic products; Table 2 is 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.

[0145] Table 1 Corresponding data of relevant industry standards for high-purity arsenic products

[0146] Table 2 Analysis of relevant parameters of high-purity arsenic prepared in Examples 1 to 8 and arsenic products prepared in Comparative Examples 1 to 6

[0147] As shown in Table 1 and Table 2, it can be seen from the results of Example 1 to Example 8 that the precise control of the temperature of catalytic cracking has a significant effect on the purity of high-purity arsenic. Example 1 successfully achieved the catalytic cracking of arsine into gaseous high-purity arsenic through a reasonable heating time at a catalytic cracking temperature of 200°C, and converted it into solid high-purity arsenic through a condensing device. In particular, in Example 2, although the temperature of catalytic cracking was reduced to 150°C, the purity of the high-purity arsenic product was still maintained, which further proved the effectiveness of adding a suitable catalyst and fully pyrolyzing arsine at an appropriate catalytic cracking temperature, and the purity of the arsine product was >7N. In addition, the catalyst type has a significant effect on the yield of high-purity arsenic prepared by arsine catalysis. By comparing Example 1, Example 6, and Example 7, it was found that when the catalyst was copper oxide, the highest high-purity arsenic yield was shown at a catalytic cracking temperature of 200°C, with a yield of 57.2%, which was significantly improved compared to the yield of high-purity arsenic catalyzed by the other two metal oxides, indicating that the selection of catalyst type is crucial. In Example 8, compared with Example 1, the mass of the catalyst was increased, so that the yield of high-purity arsenic was 58.5%, indicating that adding an appropriate mass of catalyst, combined with factors such as the catalytic cracking temperature and catalyst type, can improve the yield of high-purity arsenic.

[0148] The results of Comparative Examples 1 to 3 show that when the optimal catalytic pyrolysis temperature is not controlled, the purity of the arsenic product decreases significantly. In Comparative Example 1, the temperature of catalytic cracking is 80°C, but due to the low temperature, the pyrolysis of the gaseous arsenic is not sufficient, and the final product is only 5N grade purity. Comparative Example 4 uses metal palladium as a catalyst, but the catalytic effect is poor, and the sufficient pyrolysis of arsine and the effective removal of impurities cannot be achieved, which once again illustrates the importance of catalyst type selection for the cracking of arsine into high-purity arsenic.

[0149] The results of Comparative Examples 5 to 6 show that without adding a catalyst, the pyrolysis rate is slow, resulting in incomplete decomposition of arsine, ineffective removal of impurities, and low purity of the final product. Especially under the experimental condition of 200°C without adding a catalyst, the pyrolysis reaction is difficult to occur. Even if the temperature of the catalytic pyrolysis is increased to 500°C, the purity of the product decreases significantly, showing the importance of the selection of catalyst type and the temperature of the catalytic pyrolysis in the process of pyrolysis of gaseous arsenic to high-purity arsenic. Based on the above embodiments, it can be seen that in Example 1, the temperature of catalytic cracking is 200°C, the temperature of condensation is 100°C, and the flow rate of the airflow of the pyrolysis device is 1L / min / cm 2 , it is possible to obtain high-purity arsenic products with a total impurity content of <0.1ppm and a high-purity arsenic purity of >7N. This provides a strong basis for further optimizing the preparation process of high-purity arsenic, and also emphasizes the importance of proper temperature control and its removal of impurities during the pyrolysis process.

[0150] 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 catalytic cracking of gaseous arsenic compounds, characterized in that: The following steps are involved: The gaseous arsenide is catalytically cracked by a catalyst, and then condensed and collected. The condensate formed by the 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 the transition metal / noble metal.

2. The method for catalytic cracking of gaseous arsenide according to claim 1, characterized in that: The transition metal includes cobalt, nickel, copper or manganese; the noble metal includes gold, silver or platinum.

3. 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.

4. The method for catalytic cracking of gaseous arsenic compounds 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.

5. The method for catalytic cracking of gaseous arsenide according to any one of claims 1 to 4, 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.

6. 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.

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

8. 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.

9. 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.

10. A device for catalytic cracking of gaseous arsenic compounds, characterized in that: include: A catalytic cracking device, including a temperature-controllable heater, a condenser and a collector; The heater is used to catalytically crack arsine to obtain pyrolysis gas; wherein the temperature of the catalytic cracking is 100°C to 300°C; and the duration of the catalytic cracking is 1 to 2 hours; The condenser is connected to the heater and is used to condense the arsine pyrolysis product in the pyrolysis gas to form a condensate; the condensation time is 1 to 2 hours; A collector, connected to the condensation outlet of the condenser, for collecting condensate; The recovery device is connected to the gas phase outlet of the condenser and is used for collecting the gas phase.

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