Method and device for purifying gaseous arsenic compounds

Abstract

The present invention provides a method and device for purifying gaseous arsenide, wherein the gaseous arsenide is arsine gas. The gaseous arsenide is placed under the conditions of a first temperature and a first pressure for rectification, and the gaseous substance is collected to obtain arsine of first purity; the first purity arsine is passed into an adsorbent of a second temperature to remove gas impurities and dry to obtain arsine of second purity; and the second purity arsine is then heated at a third temperature to purify the gas to obtain electronic grade gaseous arsenide. The first temperature is ‑80°C to ‑10°C; the first pressure is 0.1MPa to 0.6MPa; the second temperature is 50 to 80°C, and the third temperature is 100°C to 200°C. The purity of the final product reaches the electronic grade standard, which meets the industrial production requirements of high-purity arsenic products. The process flow adopted by the present invention is simple to operate, easy to realize industrial production, and can also reduce production costs.

Description

Technical Field

[0001] The present invention relates to the field of electronic special gas purification, and in particular to a method and device for purifying gaseous arsenide. Background Art

[0002] Arsenic (AsH 3 ) is an important chemical raw material, widely used in semiconductor manufacturing, optoelectronic materials, gas phase doping and the preparation of high-purity arsenic products. Arsane is not only an important precursor of arsenide semiconductor materials (such as gallium arsenide and indium arsenide), but also a key intermediate in the synthesis of other arsenic compounds. Therefore, the purity of arsine directly affects the performance, stability and reliability of semiconductor devices, and is an indispensable basic raw material in the semiconductor industry.

[0003] However, the requirements for material purity of electronic devices are increasing day by day. Traditional methods for preparing and purifying arsine often have long process cycles and require multiple stages of condensation, adsorption and impurity removal. For example, in some technical solutions disclosed in related technologies, crude arsine is first generated, and then the crude arsine is subjected to two-stage condensation, multiple cold traps, two-stage distillation, and three-stage adsorption to obtain ultra-pure arsine.

[0004] Therefore, simplifying the process steps and improving the purity of arsine have become the key links to enhance its industrial application value. Based on this, it is necessary to provide a method and device for purifying gaseous arsenide 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 purifying gaseous arsenide to solve the technical problems of complicated process steps and high production cost in the existing preparation of high-purity arsine.

[0006] To achieve the above object, the present invention provides a method for purifying gaseous arsenic compounds, the specific steps of which include:

[0007] The gaseous arsenide is placed under the conditions of a first temperature and a first pressure for distillation, and the gaseous substance is collected to obtain arsine with a first purity.

[0008] The first purity arsine is passed into an adsorbent at a second temperature to remove gas impurities and dry the arsine to obtain arsine of second purity.

[0009] The second purity arsine is then heated at a third temperature to purify the gas to obtain electronic grade gaseous arsenide.

[0010] Wherein, the second temperature is 50-80°C; the third temperature is 100-200°C.

[0011] According to an implementation manner of the present application, the first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

[0012] According to the above-mentioned method for purifying gaseous arsenide, the step of subjecting the gaseous arsenide to distillation under the conditions of a first temperature and a first pressure comprises:

[0013] The gaseous arsenide is placed in a light-removal tower under the conditions of a first temperature and a first pressure for rectification, wherein the bottom temperature of the light-removal tower is 20-40° C. higher than the top temperature of the tower.

[0014] The bottom material after distillation in the light-removal tower is placed in a heavy-removal tower under the conditions of a first temperature and a first pressure for distillation, and the material at the top of the tower is collected to obtain arsine with a first purity; wherein, in the heavy-removal tower, the bottom temperature is 20-40° C. higher than the top temperature; the top temperature of the light-removal tower, the bottom temperature of the light-removal tower, the top temperature of the heavy-removal tower, and the bottom temperature of the heavy-removal tower are all within the temperature range of the first temperature, and the top temperature of the heavy-removal tower is 5-10° C. higher than the top temperature of the light-removal tower.

[0015] According to the implementation mode of the present application, the top temperature of the lightness removal tower is -80~-60°C, the bottom temperature is -40~-20°C; and the first pressure is 0.1MPa~0.6MPa.

[0016] The top temperature of the deweighting tower is -70 to -50°C, and the bottom temperature is -30 to -10°C.

[0017] According to an embodiment of the present application, the adsorbent is at least one of pore-adjusting carbon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve and activated alumina.

[0018] According to an embodiment of the present application, in the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 120°C to 180°C.

[0019] According to an embodiment of the present application, the gaseous arsenide is prepared by uniformly mixing a metal arsenide and a sulfuric acid solution at a temperature of 20-40° C. and a vacuum pressure of 1-100 Pa.

[0020] Wherein, the metal arsenide is one of zinc arsenide, magnesium arsenide and aluminum arsenide.

[0021] The mass concentration of the sulfuric acid solution is 5-20%, and the mass ratio of the metal arsenide to the sulfuric acid solution is (5-15):100.

[0022] According to an embodiment of the present application, the first purity arsine contains arsine and impurities; wherein the impurities contain at least one of antimonane, silane, phosphine, hydrogen sulfide, and germane.

[0023] According to an embodiment of the present application, the second purity arsine contains arsine and thermodynamically unstable substances; the thermodynamically unstable substances contain at least one of oxygen, carbon dioxide, nitrogen, germane, and antimone.

[0024] The present application also provides a gaseous arsenic purification device, comprising:

[0025] The distillation mechanism is used to distill the gaseous arsenide under the conditions of a first temperature and a first pressure, collect the gaseous substance, and obtain arsine of a first purity; the first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

[0026] An adsorption mechanism has an adsorbent inside, the adsorption mechanism is connected to the distillation mechanism, and the adsorption mechanism is used to pass the first purity arsine into the adsorbent at a second temperature to remove gas impurities and dry it to obtain the second purity arsine; the second temperature is 50~80℃.

[0027] A heating mechanism is connected to the adsorption mechanism, and is used to pass the second purity arsine into the heating mechanism and heat it at a third temperature to purify the gas to obtain electronic grade gaseous arsenide; the third temperature is 100°C to 200°C.

[0028] Beneficial effects:

[0029] In the above-mentioned method for purifying gaseous arsenide, the gaseous arsenide is placed in an atmosphere of a first temperature and a first pressure, and low-boiling impurities and most high-boiling impurities are removed by utilizing the difference in boiling points, and the gaseous substances obtained by distillation are collected to obtain arsine of first purity; the first-purity arsine is passed into a heated adsorbent, which is used not only to remove hydrogen sulfide, hydrogen and water, but also to simultaneously activate other thermodynamically unstable impurities to obtain arsine of second purity; and then pyrolysis is performed by heating to remove the thermodynamically unstable impurities. Through the above multi-stage impurity removal, gaseous alkane impurities are deeply removed, especially the content of antimony alkane impurities in the same family as arsine is greatly reduced, and high-purity arsine of extremely high purity is obtained, which provides extremely high-quality raw materials for the subsequent preparation of high-purity metallic arsenic and arsenide.

[0030] The above-mentioned method for purifying gaseous arsenide adopts a three-stage impurity removal process flow which is not only simple to operate and easy to realize industrial production, but also can reduce production costs. It is an efficient and economical method for purifying gaseous arsenide. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] 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.

[0032] Figure 1 It is a schematic diagram of the operation flow of Examples 1 to 9 of the present application;

[0033] Figure 2 It is a schematic diagram of the distillation mechanism of the present application.

[0034] 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

[0035] 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.

[0036] 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.

[0037] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0038] After extensive research, the applicant found that in the related technology pointed out in the background technology, crude arsine is produced by reacting arsenic zinc compounds with acids; then, after low-temperature freezing and impurity removal by two-stage condensation, multiple cold traps alternately collect and compress the gas to provide a stable gas source for the subsequent arsine refining process. Next, a combination of two-stage low-temperature and low-pressure distillation and multi-stage adsorption is used to remove impurities in the crude arsine to obtain ultra-pure arsine. However, the process steps are complicated, and the high and low boiling point impurities separated have not been specifically reported.

[0039] The applicant also found that the reaction of arsenic zinc compounds with acids to prepare arsine produces a variety of impurities, such as hydride impurities containing metal elements such as antimony, lead, and cadmium. These impurities have similar chemical properties to arsine and are difficult to remove by traditional methods. In particular, antimony alkane (SbH 3 ) impurities, which are similar to arsine in chemical structure, make the removal process more complicated. If they cannot be removed as much as possible in ultrapure arsine, the purity of arsine will fail to meet the electronic grade requirements, which will not only affect the physical and chemical properties of arsine, but also may cause instability in subsequent applications, thereby reducing the performance of electronic devices. Therefore, although the purity of ultrapure arsine in the related art is also very high, it is difficult to predict whether it can reduce the antimonane impurities to a suitable concentration and whether it is suitable for subsequent applications.

[0040] To achieve the above object, the present invention provides a method for purifying gaseous arsenic compounds, the specific steps of which include:

[0041] S100: placing gaseous arsenide in a distillation mechanism under the conditions of a first temperature and a first pressure for distillation, collecting gaseous substances, and obtaining arsine of a first purity. The first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

[0042] In some embodiments, a low-pressure condensation and rectification device is used, which contains a light-removal tower and a heavy-removal tower. By adjusting the top and bottom temperatures of the light-removal tower, the light-component gaseous substance is easily volatile and exists at the top of the light-removal tower because the boiling point of the light-component gaseous substance is lower than that of arsine. The light-component gaseous substance is separated to obtain a liquid substance, which is collected by a first gaseous recovery device. The liquid substance is collected at the bottom of the light-removal tower by a first liquid recovery device.

[0043] In some other embodiments, the light gaseous component has a boiling point lower than that of arsine, also known as a low-boiling impurity, and includes methane, ethane, or silane.

[0044] In some embodiments, a light component gas is separated out through a light removal tower to obtain a liquid. The liquid is then sent to a de-weighting tower, and by regulating the top and bottom temperatures of the de-weighting tower, the heavy component material is liquefied into a heavy component liquid because the boiling point of the heavy component material is higher than the boiling point of arsine, and is present at the bottom of the de-weighting tower. The heavy component liquid is separated to obtain arsine gas of first purity. The first purity arsine gas is at the top of the de-weighting tower and is collected by a first collector. The heavy component liquid is at the bottom of the de-weighting tower and is collected by a second liquid recovery device.

[0045] In yet other embodiments, the heavy components having a boiling point higher than that of arsine, also referred to as high-boiling impurities, include antimonane.

[0046] S200: passing the first purity arsine into an adsorbent at a second temperature to remove gas impurities and drying to obtain second purity arsine.

[0047] In some embodiments, in the step of passing the first purity arsine into an adsorbent at a second temperature, the second temperature is 50°C to 80°C.

[0048] In some embodiments, the adsorbent is at least one of pore-adjusting carbon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve and activated alumina. The microporous structure of the adsorbent selectively adsorbs different molecules, effectively removing small molecular kinetic diameter impurities (such as hydrogen sulfide, hydrogen, etc.) in arsine, and significantly reducing the residual impurity content in arsine.

[0049] Hydrogen sulfide and arsine have similar boiling points, but their molecular dynamic diameters are greatly different. Therefore, by passing the first-purity arsine into the adsorbent at the second temperature, impurities in the first-purity arsine, such as hydrogen sulfide and volatile organic compounds, are removed to prevent the impurities from clogging the pipeline in the subsequent steps and affecting the efficiency of gaseous arsine purification. The gas can also be dried to obtain the second-purity arsine. At the same time, by passing the first-purity arsine into the adsorbent at the second temperature, other thermodynamically unstable impurities can also be activated simultaneously.

[0050] Under the condition of the second temperature within the above temperature range, on the one hand, the adsorption effect of the adsorbent is improved and energy consumption can be reduced. This is because the molecules adsorbed on the adsorbent are more likely to escape into the gas phase due to the intensified thermal motion, thereby increasing the adsorption rate of the adsorbent. On the other hand, this temperature has a suitable temperature difference from the third temperature, so that the thermodynamically unstable impurities can be activated so that they are easy to decompose in S300, such as using a relatively low heating temperature or heating time; and they will not be decomposed in advance in the adsorption step, thereby avoiding the antimony generated by the premature decomposition of antimony alkane from clogging the pores of the adsorbent, reducing the adsorption effect of the adsorbent, or reducing the regeneration efficiency of the adsorbent.

[0051] S300: The second purity arsine is then heated at a third temperature to purify the gas, thereby obtaining electronic grade gaseous arsenide. In the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 100°C to 200°C.

[0052] In some embodiments, in the step of purifying the gas by heating the second purity arsine at a third temperature, the antimonane impurity is mainly removed. The gaseous arsenide is distilled to remove low-boiling impurities and most high-boiling impurities, and then introduced into the adsorbent at the second temperature to remove hydrogen sulfide and simultaneously activate other thermodynamically unstable impurities, so that the second purity arsine contains only a small amount of thermodynamically unstable impurities. Therefore, after purifying the gas by adjusting the third temperature, electronic grade gaseous arsenide is obtained.

[0053] If the third temperature is too high, arsine will be thermally decomposed, while if it is too low, antimonane impurities cannot be effectively removed. Therefore, the third temperature is adjusted to 100 ℃~200 ℃, and antimonane impurities can be removed by thermal decomposition.

[0054] In some specific embodiments, in the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 120°C to 180°C.

[0055] In general, the gas obtained by purifying the second purity arsine by heating at the third temperature is electronic grade gaseous arsenide. The specific separation principle of antimonane and electronic grade gaseous arsenide in the second purity arsine is as follows:

[0056] According to DFT theoretical calculations, electronic grade gaseous arsenide, the main component of which is arsine (AsH 3 ) has an arsenic-hydrogen bond dissociation energy of 80.3 kcal / mol, and antimonane (SbH 3 ) has an antimony hydrogen bond dissociation energy of 67.7 kcal / mol.

[0057] Convert bond breaking energy from kcal / mol to J / mol (thermal decomposition formula in SI units):

[0058] 1kcal / mol=4184 J / mol.

[0059] Arsenic bond breaking energy: ΔH(AsH 3 )=80.3 kcal / mol×4184=336779.2 J / mol.

[0060] Antimonane bond breaking energy: ΔH(SbH 3 )=67.7kcal / mol×4184=283236.8 J / mol.

[0061] The pyrolysis temperature T can be approximately estimated by the formula: T=ΔH / ΔS.

[0062] Where ΔH is the enthalpy change of the reaction, corresponding to the bond breaking energy, usually expressed in kcal / mol. ΔS is the entropy increase of the molecule during the decomposition process, here expressed as 20 cal / (mol·K).

[0063] By calculating with thermodynamic formula, it can be deduced that the theoretical temperature for bond breaking in arsine is 4024 K, and the theoretical temperature for bond breaking in antimonane is 3384 K. Among them, the temperature required for breaking the antimony hydrogen bond in antimonane is lower.

[0064] It should be noted that the theoretical calculation value ignores the influence of factors such as catalyst and decomposition pressure, so the theoretical calculation temperature required for bond breaking is too high. In actual pyrolysis temperature, it may be as low as half of the theoretical temperature or even lower. The third temperature involved in this application is the actual temperature determined by relevant experiments.

[0065] Although the theoretical calculation of the temperature required for bond breaking is much higher than the experimental pyrolysis temperature, it still shows that antimony hydrogen bonds are easier to decompose than arsenic hydrogen bonds at relatively lower temperatures.

[0066] According to molecular dynamics simulation calculations, at 200K, the bond length of arsine is 1.59Å; the bond length of antimonane is 1.80Å. At 700K, the bond length of arsine is 1.70Å; the bond length of antimonane is 1.95Å. Molecular dynamics simulation calculations also show that antimonane has a longer bond length than arsine and is relatively easy to decompose.

[0067] Therefore, the method of regulating the third temperature is adopted, mainly to control the decomposition and removal of antimonane to obtain electronic grade gaseous arsenide products.

[0068] In the above-mentioned method for purifying gaseous arsenide, the gaseous arsenide is placed under the conditions of a first temperature and a first pressure, and the gaseous substance obtained by distillation is collected by utilizing the difference in boiling points, which is the first purity arsine; the first purity arsine is passed into an adsorbent at a second temperature, and in addition to removing hydrogen sulfide, hydrogen and water, other thermodynamically unstable impurities are simultaneously activated to obtain the second purity arsine; and the second purity arsine is then heated at a third temperature to purify the gas, which is the electronic grade gaseous arsenide. Among them, the second purity arsine is heated at the third temperature to break the antimony hydrogen bond in antimony, thereby achieving the thermal decomposition and removal of the antimony impurities. In some embodiments, the above-mentioned impurity removal method can effectively reduce the impurity content in the gaseous arsenide to a minimum, and obtain a deeply purified ultra-high purity electronic grade gaseous arsenide.

[0069] The purity of the electronic-grade gaseous arsenide product prepared by the above-mentioned gaseous arsenide purification method reaches the electronic-grade standard, which meets the industrial production requirements of high-quality and high-purity arsenic products. At the same time, the process flow adopted by the present invention is not only simple to operate and easy to realize industrial production, but also can reduce production costs, and is an efficient and economical gaseous arsenide purification method.

[0070] The distillation step can be carried out by using a distillation mechanism of a single distillation tower for distillation separation, or by using a combination of multiple distillation towers for distillation separation. Exemplarily, the distillation mechanism includes a light removal tower and a heavy removal tower; the light removal tower and the heavy removal tower are connected in series. Among them, the distillation mechanism mainly separates the components by the difference in boiling points, and the low boiling point (light) impurities and the high boiling point (heavy) impurities are mainly separated by two-stage tower tops and tower bottoms.

[0071] Accordingly, in some embodiments, the step of subjecting the gaseous arsenide to distillation under the conditions of a first temperature and a first pressure includes:

[0072] The gaseous arsenide is placed in a light-removal tower under the conditions of a first temperature and a first pressure for rectification, wherein the bottom temperature of the light-removal tower is 20-40° C. higher than the top temperature of the tower.

[0073] In this step, the light-removal tower is mainly used to remove lighter impurities (such as methane, ethane, silane and other low-boiling impurities). Since the top temperature of the tower is relatively low, the light components can be more volatile and separated.

[0074] The bottom material after distillation in the light-removal tower is placed in a heavy-removal tower under the conditions of a first temperature and a first pressure for distillation, and the material at the top of the tower is collected to obtain arsine of a first purity. Wherein, in the heavy-removal tower, the tower bottom temperature is 20-40°C higher than the tower top temperature; the tower top temperature of the light-removal tower, the tower bottom temperature of the light-removal tower, the tower top temperature of the heavy-removal tower, and the tower bottom temperature of the heavy-removal tower are all within the first temperature range, and the tower top temperature of the heavy-removal tower is 5-30°C higher than the tower top temperature of the light-removal tower.

[0075] In this step, the deweighting tower is mainly used to remove high-boiling impurities (such as water, antimony or other high-boiling substances). The temperature at the bottom of the tower is higher than the temperature at the top of the tower, which promotes the liquid precipitation and reflux separation of the heavy components.

[0076] In some embodiments, the top temperature of the light removal tower is -80~-60°C, the bottom temperature is -40~-20°C; and the first pressure is 0.1MPa~0.6MPa.

[0077] The top temperature of the deweighting tower is -70 to -50°C, and the bottom temperature is -30 to -10°C.

[0078] In some embodiments, the gaseous arsenide is prepared by uniformly mixing a metal arsenide and a sulfuric acid solution at a temperature of 20-40° C. and a vacuum pressure of 1-100 Pa.

[0079] Wherein, the metal arsenide is one of zinc arsenide, magnesium arsenide and aluminum arsenide.

[0080] The mass concentration of the sulfuric acid solution is 5-20%, and the mass ratio of the metal arsenide to the sulfuric acid solution is (5-15):100.

[0081] In some embodiments, the first purity arsine comprises arsine and impurities; wherein the impurities contain at least one of antimonane, silane, phosphine, hydrogen sulfide, and germane.

[0082] In some embodiments, the second purity arsine contains arsine and thermodynamically unstable substances; the thermodynamically unstable substances contain at least one of oxygen, carbon dioxide, nitrogen, germane, and antimonane.

[0083] The present application also provides a gaseous arsenic purification device, comprising:

[0084] The distillation mechanism is used to distill the gaseous arsenide under the conditions of a first temperature and a first pressure, collect the gaseous substance, and obtain arsine of a first purity; the first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

[0085] See also Figure 2 , Figure 2 The distillation mechanism of the present application is shown in the figure. The distillation mechanism includes a light removal tower top A; a light removal tower body (packing section) B; a light removal tower bottom C; a heavy removal tower top D; a heavy removal tower body (packing section) E; a heavy removal tower bottom F; number 1 is the gaseous arsenide inlet; number 2 is the low boiling point impurity outlet; number 3 is the path for the liquid to enter the heavy removal tower from the light removal tower bottom; number 4 is the first purity arsine outlet; number 5 is the high boiling point impurity outlet.

[0086] In some embodiments, the gaseous arsenide is placed in a distillation mechanism, and the light component gaseous substance is separated into a liquid substance through a light removal tower; and the heavy component liquid substance is then separated into the first purity arsine through a heavy removal tower.

[0087] In some embodiments, the distillation mechanism is a low-pressure condensation distillation device capable of regulating temperature and pressure.

[0088] In some embodiments, the gaseous arsenide is prepared by a reactor, and the reactor is directly connected to the distillation mechanism, for example, without a condenser being provided between the two.

[0089] The adsorption mechanism has an adsorbent inside, and the adsorption mechanism is connected to the distillation mechanism. The adsorption mechanism is used to pass the first purity arsine into the adsorbent at the second temperature to remove gas impurities and dry it to obtain the second purity arsine.

[0090] In some embodiments, the adsorption mechanism may be a straight tower filled with an adsorbent. The first purity arsine passes through the straight tower, and the adsorbent removes hydrogen sulfide and dries the gas to obtain second purity arsine.

[0091] A heating mechanism is connected to the adsorption mechanism, and is used to pass the second purity arsine into the adsorption mechanism for heating at a third temperature to obtain purified gas; the third temperature is 100°C to 200°C.

[0092] In some embodiments, the heating mechanism uses a heating kettle to remove thermodynamically unstable impurities in arsine, such as oxygen, carbon dioxide, nitrogen, germane, or antimony remaining after the distillation mechanism and adsorption mechanism steps, by heating in a closed atmosphere. Arsine exists and is collected in a gaseous state, thereby achieving the purpose of separation and impurity removal. At the same time, the control of the third temperature of the heating mechanism also avoids the thermal decomposition of arsine, further improving the purity and content of arsine.

[0093] In some embodiments, the above-mentioned gaseous arsenic purification device further includes:

[0094] The first purifier includes a first gas recovery device, a first liquid recovery device, a second liquid recovery device and a first collector.

[0095] The first gas recovery device is connected to the top of the light-removing tower; the first liquid recovery device is connected to the bottom of the light-removing tower; the second liquid recovery device is connected to the bottom of the heavy-removing tower, and the first collector is connected to the top of the heavy-removing tower and the adsorption mechanism respectively.

[0096] In some embodiments, the first gaseous recoverer is used to collect the light component gaseous material; the first liquid recoverer is used to collect the liquid material; the second liquid recoverer is used to collect the heavy component liquid material; and the first collector is used to collect the first purity arsine gas.

[0097] The second purifier includes a second collector; the second collector is connected to the adsorption mechanism and the heating mechanism respectively.

[0098] In some embodiments, the second purity arsine is collected using a second collector.

[0099] The third purifier includes a second gas recovery device and a third collector.

[0100] The second gaseous recovery device is connected to the bottom outlet of the heating mechanism and is used to collect antimony or arsenic-antimony mixture, which is the product of antimonane pyrolysis; the third collector is connected to the gas phase outlet of the heating mechanism and is used to collect electronic grade gaseous arsenic.

[0101] In some embodiments, the devices in the first purifier, the second purifier and the third purifier are connected by pipelines; and the interfaces between the pipelines are connected in a sealing manner.

[0102] Exemplarily, the various devices are connected by pipelines, so that arsine and impurities can flow through the pipelines, thereby facilitating the removal of impurities.

[0103] As another example, the interfaces between the pipelines are connected in a sealed manner to ensure that the arsine gas is not lost and foreign impurities are not introduced.

[0104] For further understanding of the present invention, examples are given below:

[0105] Example 1

[0106] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0107] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves, the temperature of the adsorption device (i.e., the second temperature, the same below) is 80°C, and the adsorption operation is performed for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed, and the trace impurities that have not been removed are activated.

[0108] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism (i.e., the third temperature, the same below) is 150° C., and the heating time of the heating mechanism is 2 hours to obtain an electronic grade gaseous arsenide product with a purity of 7N.

[0109] Example 2

[0110] Among them, compared with Example 1, Example 2 changed the top and bottom temperatures of the light removal tower and the heavy removal tower.

[0111] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -76~-72℃, the bottom temperature is -40~-35℃, the top temperature of the heavy removal tower is -70~-63℃, the bottom temperature is -30~-23℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0112] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0113] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0114] Example 3

[0115] Compared with Example 1, Example 3 changes the first pressure.

[0116] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.4MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0117] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0118] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0119] Example 4

[0120] Compared with Example 1, Example 4 changes the first pressure.

[0121] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.2MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0122] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0123] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0124] Example 5

[0125] Compared with Example 1, Example 5 changes the adsorbent type.

[0126] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0127] The first purity arsine is fed into an adsorption device filled with pore-adjusting activated carbon at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The impurities with small molecular kinetic diameter are effectively removed, and trace impurities that have not been removed are activated.

[0128] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0129] Example 6

[0130] Compared with Example 1, Example 6 changes the temperature of the heating mechanism.

[0131] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0132] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0133] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 100° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0134] Example 7

[0135] In particular, compared with Example 1, Example 7 changes the adsorbent type.

[0136] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0137] The first purity arsine is fed into an adsorption device filled with 4A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The impurities with small molecular kinetic diameter are effectively removed, and trace impurities that have not been removed are activated.

[0138] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0139] Example 8

[0140] Compared with Example 1, Example 8 changes the adsorbent type.

[0141] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0142] The first purity arsine is fed into an adsorption device filled with 5A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0143] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0144] Example 9

[0145] Compared with Example 1, Example 9 changes the temperature of the adsorption device.

[0146] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0147] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 50°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The impurities with small molecular kinetic diameter are effectively removed, and trace impurities that have not been removed are activated.

[0148] The second purity arsine is introduced into a heating mechanism, the temperature of the heating mechanism is 150° C., and the heating time of the heating mechanism is 2 hours, to obtain an electronic grade gaseous arsenide product, and the purity of the product meets the standard of 7N.

[0149] Comparative Example 1

[0150] Compared with Example 1, in Comparative Example 1, the temperature of the heating mechanism is changed.

[0151] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3 ) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0152] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at a temperature of 80°C and subjected to an adsorption operation for 2 hours to obtain the second purity arsine. The small molecular kinetic diameter impurities are effectively removed and trace impurities that have not been removed are activated.

[0153] The second purity arsine is introduced into a heating mechanism at a temperature of 50° C. for 2 hours to obtain an arsine product with a purity of 4 N. Since the temperature of the heating mechanism is too low, the antimonane impurities are not completely removed, resulting in a decrease in product purity.

[0154] Comparative Example 2

[0155] In which, compared with Example 1, in Comparative Example 2, the temperature of the adsorption device was changed.

[0156] Arsine (mainly AsH) prepared by reacting metal arsenide with sulfuric acid solution 3) is sent to a low-pressure condensation distillation device, the first pressure is adjusted to 0.5MPa, the top temperature of the light removal tower is -66~-62℃, the bottom temperature is -40~-25℃, the top temperature of the heavy removal tower is -61~-52℃, the bottom temperature is -30~-15℃, and maintained for 2 hours to obtain the first purity arsine. This process effectively removes high-boiling point and low-boiling point impurities in arsine.

[0157] The first purity arsine is fed into an adsorption device filled with 3A molecular sieves at room temperature (25° C.), and an adsorption operation is performed for 2 hours to obtain second purity arsine.

[0158] The second purity arsine is introduced into a heating mechanism with a temperature of 150°C and a heating time of 2 hours to obtain an arsine product. Since the temperature of the adsorption device is relatively low, trace impurities are not fully activated, and the efficiency of the heating mechanism in pyrolyzing unactivated trace impurities is reduced, and the purity of the final product is 6N.

[0159] in, Figure 1 This is a schematic diagram of the operation flow of Examples 1 to 9 of the present application, Figure 2 Table 1 shows the boiling points of arsine and main impurities in arsine, and Table 2 shows the relevant parameters for the purification of gaseous arsenic compounds in Examples 1-9 and Comparative Examples 1-2.

[0160] Table 1 Boiling points of arsine and main impurities in arsine

[0161]

[0162] Table 2 Relevant parameters for purification of gaseous arsenide in Examples 1 to 9 and Comparative Examples 1 to 2

[0163]

[0164] Combining the data in Table 1 and Table 2, it can be seen that by regulating the light removal tower top temperature, the first pressure, the adsorbent type, the temperature of the adsorption device, and the temperature of the heating mechanism, and then controlling the light removal tower bottom temperature and the heavy removal tower top and bottom temperatures within a suitable range, all within the first temperature, the gaseous arsenide is purified to obtain electronic grade gaseous arsenide with a purity of about 7N. These key factors have a significant impact on the purity of arsine.

[0165] Wherein, the first temperature is -80°C~-10°C; the first pressure is 0.1MPa~0.6MPa.

[0166] Examples 1 to 4, through different light removal tower top temperatures and first pressure optimization, reflect the effectiveness of reaction conditions and device coordination in impurity removal. Among them, compared with Example 1, Example 2 has a lower light removal tower top temperature, but the antimony removal rate is not much different; compared with Example 1, Example 3 has a reduced first pressure, and the corresponding antimony removal rate is similar, while the silicon removal rate and sulfur removal rate are slightly increased, which all indicate that controlling the appropriate light removal tower top temperature and first pressure can effectively remove low-boiling impurities methane, ethane or silane and most of the high-boiling impurities antimonane at low temperature and low pressure.

[0167] Compared with Example 1, Examples 5 and Examples 7-8 change the adsorbent type. From the corresponding results in Table 2, the top temperature of the light removal tower, the first pressure, and the temperature of the heating mechanism are adjusted to a suitable range. The adsorbent types are 3A molecular sieve, 4A molecular sieve, and 5A molecular sieve, which can remove the impurity hydrogen sulfide and dry it to obtain the second purity arsine. At the same time, the temperature of the adsorption device is the second temperature of 50-80°C, and other thermodynamically unstable impurities can be activated simultaneously.

[0168] Compared with Example 1, although the temperature of the heating mechanism in Example 6 is reduced, the corresponding antimony removal rate is not much different, and the removal rates of sulfur and silicon are increased, which further illustrates that by regulating the temperature of the heating mechanism, the thermodynamically unstable impurities remaining in the distillation device and the adsorption device, such as a small amount of antimonane, oxygen, carbon dioxide, nitrogen or germane, can be effectively removed to obtain an electronic grade gaseous arsenide product with a purity of 7N.

[0169] The results of Comparative Examples 1 and 2 show that when the optimal reaction conditions are not controlled, the impurity content in arsine increases significantly. For example, in Comparative Example 1, the temperature of the heating mechanism is too low to remove thermodynamically unstable impurities; in Comparative Example 2, the temperature of the adsorption device is only room temperature (25°C), so the trace impurities are not fully activated, resulting in a decrease in the efficiency of the pyrolysis device and a final product purity of 6N.

[0170] In summary, in Example 1, the first pressure is regulated to be 0.5MPa, the top temperature of the light tower is -66~-62°C, the bottom temperature is -40~-25°C, the top temperature of the heavy tower is -61~-52°C, the bottom temperature is -30~-15°C, and it is maintained for 2 hours. The adsorbent uses 3A molecular sieves, the second temperature is 80°C and the adsorption operation is performed for 2 hours. The temperature of the heating mechanism is 150°C, and the heating time of the heating mechanism is 2 hours. The relatively optimal electronic-grade gaseous arsenide product can be obtained, wherein the removal rate of antimony impurities is 99.994%, the silicon removal rate is 99.2%, the sulfur removal rate is 87.2%, and the purity of the electronic-grade gaseous arsenide is 7N, showing an excellent de-impurity effect. This provides a strong basis for further optimizing the preparation process of electronic-grade arsine.

[0171] In summary, 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 purifying gaseous arsenic compounds, characterized in that: The specific steps include: placing gaseous arsenide under the conditions of a first temperature and a first pressure for distillation, collecting gaseous substances, and obtaining arsine of a first purity; Passing the first purity arsine into an adsorbent at a second temperature to remove hydrogen sulfide gas impurities and drying to obtain second purity arsine; Then, the second purity arsine is heated at a third temperature to be purified to remove antimonane impurities, thereby obtaining electronic grade gaseous arsenide; Wherein, the second temperature is 50-80°C; the third temperature is 100-200°C.

2. The method for purifying gaseous arsenide according to claim 1, characterized in that: The first temperature is -80°C to -10°C; the first pressure is 0.1MPa to 0.6MPa.

3. The method for purifying gaseous arsenic compounds according to any one of claims 1 to 2, characterized in that: The step of subjecting the gaseous arsenide to distillation under the conditions of a first temperature and a first pressure comprises: The gaseous arsenide is placed in a light-removal tower under the conditions of a first temperature and a first pressure for distillation; wherein, in the light-removal tower, the tower bottom temperature is 20-40° C. higher than the tower top temperature; The bottom material after distillation in the light-removal tower is placed in a heavy-removal tower under the conditions of a first temperature and a first pressure for distillation, and the material at the top of the tower is collected to obtain arsine with a first purity; wherein, in the heavy-removal tower, the bottom temperature is 20-40° C. higher than the top temperature; the top temperature of the light-removal tower, the bottom temperature of the light-removal tower, the top temperature of the heavy-removal tower, and the bottom temperature of the heavy-removal tower are all within the first temperature range, and the top temperature of the heavy-removal tower is 5-10° C. higher than the top temperature of the light-removal tower.

4. The method for purifying gaseous arsenic compounds according to claim 3, characterized in that: The top temperature of the light removal tower is -80~-60°C, the bottom temperature is -40~-20°C; the first pressure is 0.1MPa~0.6MPa; The top temperature of the deweighting tower is -70 to -50°C, and the bottom temperature is -30 to -10°C.

5. The method for purifying gaseous arsenic compounds according to claim 1, characterized in that: The adsorbent is at least one of pore-adjusting carbon molecular sieve, 3A molecular sieve, 4A molecular sieve, 5A molecular sieve, 10X molecular sieve and activated alumina.

6. The method for purifying gaseous arsenic compounds according to claim 1, characterized in that: In the step of heating the second purity arsine at a third temperature to purify the gas, the third temperature is 120°C to 180°C.

7. The method for purifying gaseous arsenic compounds according to claim 1, characterized in that: The gaseous arsenide is prepared by uniformly mixing a metal arsenide and a sulfuric acid solution at a temperature of 20-40° C. and a vacuum pressure of 1-100 Pa; Wherein, the metal arsenide is one of zinc arsenide, magnesium arsenide and aluminum arsenide; The mass concentration of the sulfuric acid solution is 5-20%, and the mass ratio of the metal arsenide to the sulfuric acid solution is (5-15):100.

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