Process for preparing electronic-grade monosilane by magnesium silicide method

Abstract

The invention discloses a process for preparing electronic-grade monosilane by a magnesium silicide method, which comprises the following steps: crushing a prepared silicon-magnesium alloy to a proper particle size, fully mixing with dried magnesium chloride, adding liquid ammonia, and reacting in a reaction kettle to obtain products such as monosilane, disilane, ammonia gas, hydrogen, phosphorane, arsine and the like; then introducing the process gas into an ammonia recovery tank to cool ammonia components in the process gas, and removing impurities such as residual ammonia, phosphorane and arsine in the process gas through a purification device; a by-product magnesium chloride hexammoniate obtained at the bottom of the reaction kettle is discharged to a rake dryer through a bottom valve of the reaction kettle, free ammonia in the magnesium chloride hexammoniate is removed by heating, and recovered ammonia gas is subjected to pressurized cooling separation to obtain liquid ammonia which can be used for feeding liquid ammonia in the reaction kettle, so that effective utilization of resources is realized, and the production cost is reduced; efficient utilization of ammonia gas is ensured, and waste is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of monosilane production, and in particular to a process for preparing electronic-grade monosilane by a magnesium silicide method. Background Art

[0002] When preparing electronic grade monosilane, silicon powder and magnesium powder are generally mixed and placed in a fixed bed heating furnace to prepare silicon-magnesium alloy. The prepared silicon-magnesium alloy is mixed with dried magnesium chloride and reacted in a liquid ammonia environment system to obtain the main product monosilane and by-products disilane and trisilane, as well as impurities such as H2, PH3, AsH3, etc.

[0003] The main overall reaction is as follows:

[0004]

[0005] For a long time, people believed that the by-product of the silicon-magnesium method was anhydrous magnesium chloride, which led to most people not treating the by-product separately. However, the actual by-product is magnesium chloride hexaammine, which is a complex formed by anhydrous magnesium chloride and ammonia. It has excellent reversible ammonia absorption and release properties and is a good ammonia fixing material.

[0006] However, during the reaction, the solubility of the by-product magnesium chloride hexammoniate in liquid ammonia is low, which makes it difficult to continuously discharge the solid magnesium chloride hexammoniate during the reaction. At the same time, during the preparation process, the by-product ammonia gas is generated. For every portion of monosilane generated, four portions of ammonia gas are produced. This characteristic not only increases the difficulty of ammonia treatment, but also affects the cost and efficiency of the production line. Summary of the invention

[0007] The purpose of the present invention is to provide a process for preparing electronic grade monosilane by magnesium silicide method, so as to solve the above-mentioned shortcomings in the prior art.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A process for preparing electronic grade monosilane by magnesium silicide method, the process for preparing electronic grade monosilane by magnesium silicide method comprising the following steps:

[0010] S1: silicon powder and magnesium powder are put into an alloy in a mass ratio of 1:1 to prepare a furnace, and the preparation is carried out at 500-600°C, and then the prepared silicon-magnesium alloy is put into an alloy crusher, crushed to 50-80 mesh, and mixed with dried ammonium chloride to generate a reaction raw material;

[0011] S2: The reaction raw materials are put into a reactor and reacted in a liquid ammonia system to obtain reaction products such as monosilane, disilane, ammonia and hydrogen. The stirring speed of the reactor is 30-50r / min.

[0012] S3: The process gas obtained by the reaction is introduced into an ammonia recovery tank, and the ammonia component in the process gas is recovered through a condenser device at the top of the ammonia recovery tank.

[0013] S4: The crude process gas with the ammonia component is recovered and then passed through a purification device to adsorb the residual ammonia and impurities such as phosphine and arsine to obtain crude silane gas.

[0014] S5: The crude silane gas passes through the top condenser of the distillation tower 1 to intercept the heavy components such as disilane, phosphine and arsine in the silane gas, allowing monosilane and light components such as hydrogen and nitrogen to enter the distillation tower 2. Then, by adjusting the temperature of the condenser of the second tower, the light components such as hydrogen and nitrogen are discharged from the top of the tower in the form of non-condensable steam.

[0015] S6: After the receiving is completed, the kettle of the first distillation tower is heated, and the monosilane of the first distillation tower is distilled out at the top of the tower to the second distillation tower for the first distillation.

[0016] S7: The monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower. When the pressure of the second distillation tower drops rapidly, the material transfer stage is considered to be completed.

[0017] S8: Establish reflux in the three distillation towers and start discharging light components to obtain electronic grade monosilane.

[0018] S9: After the reaction is completed, the by-product obtained by the reaction - magnesium chloride hexaamine is transferred to a rake dryer for heating and deammoniation. The gas phase is pressurized by a compressor and passed into a condenser for cooling and recovery of ammonia components. The rake dryer includes a spreading component, which is used to spread the magnesium chloride hexaamine while stirring it to increase its heating area.

[0019] Preferably, in step S3, the condenser is set at a temperature of -50 to -60° C. This can reduce liquid ammonia consumption and extend the time of the purification device.

[0020] 3. According to the process for preparing electronic grade monosilane by magnesium silicide method as described in claim 1, in said step S4, the air inlet speed of the purification device is 10-30 kg / h.

[0021] Preferably, in the step S5, after the reaction in S5 stops, the monosilane receiving stage ends, the pressure of the first tower and the second tower is maintained at normal pressure, the temperature of the condenser of the first tower is -90±10°C, and the temperature of the condenser of the second tower is -130±10°C.

[0022] Preferably, in step S6, the kettle temperature of the first distillation tower is evaporated to -60°C, the first distillation is completed, the pressure of the first distillation tower is atmospheric pressure, and the condenser is set to a temperature of -110±10°C.

[0023] Preferably, in step S7, the monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower through a bottom pipe, so that heavy components such as disilane entrained in the first distillation or receiving stage can be removed.

[0024] Preferably, in step S8, the three distillation towers are set up for full reflux for two hours.

[0025] Preferably, it comprises a bracket, a warehouse body is fixedly arranged on the bracket, a rotating shaft is rotatably arranged on the warehouse body, a reciprocating tube is slidably arranged on the rotating shaft, a rake rod is fixedly arranged on the reciprocating tube, and a rake head is rotatably arranged on the rake rod;

[0026] A power storage rod and an ejection rod are slidably provided on the rake rod, a second spring is provided between the power storage rod and the ejection rod, two ends of the second spring are respectively fixedly connected to the power storage rod and the ejection rod, a second convex block is fixedly provided on the ejection rod, a spiral groove is provided on the rake head, and the second convex block is provided in the spiral groove;

[0027] It also includes a force storage assembly, which is used to make the force storage rod slide and the second spring compress during the rotation of the shaft to store force on the ejection rod;

[0028] The release assembly is used to release the ejection rod of the second spring after the second spring is compressed.

[0029] Preferably, the power storage assembly comprises a fixed ring fixedly arranged on the rotating shaft, a telescopic block is slidably arranged on the fixed ring, a cross bar is fixedly arranged on the telescopic block, and the rake rod and the power storage rod are both slidably connected to the cross bar;

[0030] A first spring is arranged between the telescopic block and the fixed ring, and two ends of the first spring are fixedly connected to the telescopic block and the fixed ring respectively;

[0031] An arc-shaped rod is fixedly arranged on the warehouse body, and the cross bar abuts against the outer side surface of the arc-shaped rod.

[0032] Preferably, the release assembly comprises a block slidably arranged on the rake rod, a slot is arranged on the ejection rod, and the block is engaged with the slot;

[0033] A push rod is slidably arranged on the rake rod, a round rod is fixedly arranged on the push rod, an inclined groove is arranged on the pull block, and the round rod is slidably arranged in the inclined groove;

[0034] A third spring is arranged between the push rod and the rake rod, two ends of the third spring are respectively fixedly connected to the push rod and the rake rod, and the push rod is in contact with the cross bar.

[0035] In the above technical scheme, the process for preparing electronic grade monosilane by magnesium silicide method provided by the present invention has the beneficial effects as follows:

[0036] 1. The prepared silicon-magnesium alloy is crushed into a suitable particle size, fully mixed with the dried magnesium chloride, and liquid ammonia is added to react in a reactor to obtain products such as monosilane, disilane, ammonia, hydrogen, phosphine and arsine, and then introduced into an ammonia recovery tank to cool the ammonia component in the process gas, and then the residual ammonia and impurities such as phosphine and arsine in the process gas are removed by a purification device; the by-product hexaammine magnesium chloride obtained at the bottom of the reactor tower is discharged to a rake dryer through the bottom valve of the reactor, and the free ammonia in the hexaammine magnesium chloride is removed by heating. The recovered ammonia is then pressurized, cooled and separated to obtain liquid ammonia, which can be used for liquid ammonia feeding in the reactor, so as to achieve effective utilization of resources and reduce production costs, ensure efficient utilization of ammonia and reduce waste.

[0037] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

[0038] This application document provides an overview of various implementations or examples of the technology described in the present disclosure, and is not a comprehensive disclosure of the entire scope or all features of the disclosed technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0040] Figure 1 A process flow chart of preparing electronic grade monosilane by the magnesium silicide method provided in an embodiment of the present invention;

[0041] Figure 2 A schematic diagram of the overall structure of a warehouse provided in an embodiment of the present invention;

[0042] Figure 3 A schematic diagram of the internal structure of a warehouse provided in an embodiment of the present invention;

[0043] Figure 4 A schematic diagram of the reciprocating tube and rake rod structure provided in an embodiment of the present invention;

[0044] Figure 5 A schematic diagram of the structure of a rotating shaft and a reciprocating rod provided in an embodiment of the present invention;

[0045] Figure 6 A schematic diagram of a fixed tube deployment structure provided by an embodiment of the present invention;

[0046] Figure 7 A cross-sectional view of a rake rod provided by an embodiment of the present invention;

[0047] Figure 8 A schematic diagram of the structure of a rake head and a release assembly provided in an embodiment of the present invention;

[0048] Fig. 9 A side cross-sectional view of a warehouse body provided in an embodiment of the present invention.

[0049] Description of reference numerals:

[0050] 1. Bracket; 11. Bin body; 2. Rotating shaft; 21. Fixed ring; 22. Telescopic block; 23. Cross bar; 24. First spring; 3. Reciprocating tube; 31. First protrusion; 4. Rake rod; 41. Block; 42. Bevel groove; 5. Rake head; 51. Spiral groove; 6. Power storage rod; 61. Pop-up rod; 62. Second spring; 63. Slot; 64. Second protrusion; 7. Push rod; 71. Round rod; 72. Third spring; 8. Fixed tube; 81. Reciprocating groove; 9. Arc rod. DETAILED DESCRIPTION

[0051] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0052] Please refer to 1-9, a process for preparing electronic grade monosilane by magnesium silicide method, the process for preparing electronic grade monosilane by magnesium silicide method comprises the following steps:

[0053] S1: silicon powder and magnesium powder are put into an alloy in a mass ratio of 1:1 to prepare a furnace, and the preparation is carried out at 500-600°C, and then the prepared silicon-magnesium alloy is put into an alloy crusher, crushed to 50-80 mesh, and mixed with dried ammonium chloride to generate a reaction raw material;

[0054] S2: The reaction raw materials are put into a reactor and reacted in a liquid ammonia system to obtain reaction products such as monosilane, disilane, ammonia and hydrogen. The stirring speed of the reactor is 30-50r / min.

[0055] S3: The process gas obtained by the reaction is introduced into an ammonia recovery tank, and the ammonia component in the process gas is recovered through a condenser device at the top of the ammonia recovery tank.

[0056] S4: The crude process gas with the ammonia component is recovered and then passed through a purification device to adsorb the residual ammonia and impurities such as phosphine and arsine to obtain crude silane gas.

[0057] S5: The crude silane gas passes through the top condenser of the distillation tower 1 to intercept the heavy components such as disilane, phosphine and arsine in the silane gas, allowing monosilane and light components such as hydrogen and nitrogen to enter the distillation tower 2. Then, by adjusting the temperature of the condenser of the second tower, the light components such as hydrogen and nitrogen are discharged from the top of the tower in the form of non-condensable steam.

[0058] S6: After the receiving is completed, the kettle of the first distillation tower is heated, and the monosilane of the first distillation tower is distilled out at the top of the tower to the second distillation tower for the first distillation.

[0059] S7: The monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower. When the pressure of the second distillation tower drops rapidly, the material transfer stage is considered to be completed.

[0060] S8: Establish reflux in the three distillation towers and start discharging light components to obtain electronic grade monosilane.

[0061] S9: After the reaction is completed, the byproduct magnesium chloride hexaamine obtained by the reaction is transferred to a rake dryer for heating and deammoniation, and the obtained gas phase is pressurized by a compressor and passed into a condenser for cooling and recovery of ammonia components. The rake dryer includes a spreading component, which is used to spread the magnesium chloride hexaamine while stirring it to increase its heating area;

[0062] The invention comprises the following steps: crushing the prepared silicon-magnesium alloy into suitable particle sizes, fully mixing the mixture with dried magnesium chloride, adding liquid ammonia to react in a reactor, obtaining products such as monosilane, disilane, ammonia, hydrogen, phosphine and arsine, and then introducing the products into an ammonia recovery tank to cool ammonia components in process gas, and removing residual ammonia and impurities such as phosphine and arsine in the process gas through a purification device; and discharging the byproduct hexaammine magnesium chloride obtained at the bottom of the reactor tower to a rake dryer through a bottom valve of the reactor, heating the magnesium chloride hexaammine to remove free ammonia in the magnesium chloride hexaammine, and separating the recovered ammonia gas through pressurization cooling to obtain liquid ammonia, which can be used for adding liquid ammonia to the reactor.

[0063] The purified process gas is received by the silane tower 1 and tower 2. During the receiving process, part of the monosilane, disilane, trisilane, phosphine and other heavy component impurities are retained in the kettle of the first tower; the temperature of the condenser of the second tower is adjusted to cool the received crude monosilane to the liquid phase and leave it at the bottom of the kettle. Light component impurities such as H2, N2 and other impurities are removed in the form of non-condensable gas. After the receiving is completed, the first tower is heated and distilled, and the monosilane remaining at the bottom of the kettle of the first tower is distilled to the second tower. The monosilane in the second tower is then transferred to the third tower to remove the heavy components entrained during the receiving and distillation. Finally, the electronic grade monosilane is obtained by distillation in the third tower.

[0064] In an embodiment further provided by the present invention, in step S3, the condenser is set at a temperature of -50 to -60° C. This can reduce the consumption of liquid ammonia and extend the time of the purification device.

[0065] In an embodiment further provided by the present invention, in step S4, the air intake rate of the purification device is 10-30 kg / h.

[0066] In an embodiment further provided by the present invention, in step S5, after the S5 reaction stops, the monosilane receiving stage ends, the pressure of the first tower and the second tower is maintained at normal pressure, the temperature of the condenser of the first tower is -90±10°C, and the temperature of the condenser of the second tower is -130±10°C.

[0067] In an embodiment further provided by the present invention, in step S6, the kettle temperature of the first distillation tower is evaporated to -60°C, the first distillation is completed, the pressure of the first distillation tower is atmospheric pressure, and the condenser is set to a temperature of -110±10°C.

[0068] In an embodiment further provided by the present invention, in step S7, the monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower through a bottom pipe, so that heavy components such as disilane entrained in the first distillation or receiving stage can be removed.

[0069] In an embodiment further provided by the present invention, in step S8, the three distillation towers are set up with full reflux for two hours.

[0070] Further, it includes a bracket 1, a bin body 11 is fixedly arranged on the bracket 1, a rotating shaft 2 is rotatably arranged on the bin body 11, a reciprocating tube 3 is slidably arranged on the rotating shaft 2, a rake rod 4 is fixedly arranged on the reciprocating tube 3, a rake head 5 is rotatably arranged on the rake rod 4; a storage rod 6 and an ejection rod 61 are slidably arranged on the rake rod 4, a second spring 62 is arranged between the storage rod 6 and the ejection rod 61, the two ends of the second spring 62 are respectively fixedly connected to the storage rod 6 and the ejection rod 61, and the ejection rod 61 is fixedly arranged with a second spring 62. The second protrusion 64 is provided on the rake head 5 with a spiral groove 51, and the second protrusion 64 is provided in the spiral groove 51; it also includes a power storage component, which is used to make the power storage rod 6 slide during the rotation of the shaft 2, compress the second spring 62, and store power on the pop-up rod 61; a release component, which is used to release the pop-up rod 61 after the second spring 62 is compressed, and when the shaft 2 rotates, the reciprocating rod drives the rake rod 4 and the rake head 5 to rotate, so that the rake head 5 can remove the hexachlorobenzene located at the bottom of the warehouse body 11. After the magnesium chloride hexaamine is scooped up, during the rotation of the rake rod 4, the power storage rod 6 slides and compresses the second spring 62. After the power storage rod 6 completes the compression and power storage of the second spring 62, the release assembly releases the fixation of the ejection rod 61. Under the action of the second spring 62, the ejection rod 61 slides and pops out. Through the cooperation of the second protrusion 64 and the spiral groove 51, when the ejection rod 61 pops out, the rake head 5 rotates to scatter the magnesium chloride hexaamine on the rake head 5, so that the magnesium chloride hexaamine is Magnesium fully absorbs the heat in the warehouse body 11, and accelerates the deammoniation efficiency of magnesium chloride hexammine; further, the spiral grooves 51 arranged on the rake heads 5 on the reciprocating tubes 3 on both sides are in opposite directions, and when the pop-up rod 61 slides and the rake heads 5 rotate, the rake heads 5 arranged on the reciprocating tubes 3 on both sides scatter the magnesium chloride hexammine scooped up by the rake heads 5 to the other side, avoiding the accumulation of magnesium chloride hexammine on one side of the bottom of the warehouse body 11 after the rake heads 5 scatter the magnesium chloride hexammine, thereby improving the heating deammoniation efficiency of magnesium chloride hexammine.

[0071] The force storage component includes a fixed ring 21 fixedly arranged on the rotating shaft 2, a telescopic block 22 is slidably arranged on the fixed ring 21, a cross bar 23 is fixedly arranged on the telescopic block 22, and the rake rod 4 and the force storage rod 6 are both slidably connected with the cross bar 23; a first spring 24 is arranged between the telescopic block 22 and the fixed ring 21, and the two ends of the first spring 24 are respectively fixedly connected with the telescopic block 22 and the fixed ring 21; an arc rod 9 is fixedly arranged on the warehouse body 11, and the cross bar 23 abuts against the outer side surface of the arc rod 9. After the rake head 5 picks up the magnesium chloride hexammoniate, the cross bar 23 passes through the position of the arc rod 9 and abuts against the arc rod 9. In the process of rotation of the rake rod 4 and the rake head 5, under the action of the arc rod 9, the cross bar 23 slides relative to the rake rod 4, pushing the force storage rod 6 to slide and The second spring 62 is compressed, and after the cross bar 23 slides to complete the compression of the second spring 62, the fixation of the pop-up rod 61 is released by releasing the assembly, thereby completing the effect of scattering the magnesium chloride hexaamine on the rake head 5; and after the second spring 62 is compressed and stored, the initial velocity of the pop-up rod 61 when it pops out is relatively large, so that the magnesium chloride hexaamine on the rake head 5 can be scattered more dispersedly, and the contact area between the magnesium chloride hexaamine and the hot air in the warehouse body 11 is increased, so that the heating and deammoniation of the magnesium chloride hexaamine is more efficient; when the cross bar 23 pushes the power storage rod 6 to slide, the first spring 24 is stretched, and after the cross bar 23 is separated from the arc rod 9, under the resetting action of the first spring 24, the cross bar 23 slides and resets, and at the same time drives the power storage rod 6, the pop-up rod 61 and the rake head 5 to reset.

[0072] The release assembly includes a block 41 slidably arranged on the rake rod 4, a slot 63 is arranged on the pop-up rod 61, and the block 41 is engaged with the slot 63; a push rod 7 is slidably arranged on the rake rod 4, a round rod 71 is fixedly arranged on the push rod 7, an inclined groove 42 is arranged on the pull block, and the round rod 71 is slidably arranged in the inclined groove 42; a third spring 72 is arranged between the push rod 7 and the rake rod 4, and the two ends of the third spring 72 are respectively fixedly connected to the push rod 7 and the rake rod 4, and the push rod 7 is connected to the cross bar 2 3, under the engagement of the block 41 and the slot 63, the ejection rod 61 is fixed, and the force storage rod 6 slides to compress and store force on the second spring 62. During the sliding process of the force storage rod 6, it abuts against the push rod 7 and pushes the push rod 7 to slide. The push rod 7 cooperates with the round rod 71 and the inclined slot 42 to make the block 41 slide. After the force storage rod 6 slides to store force on the second spring 62, the block 41 slides to disengage from the slot 63, completing the release of the ejection rod 61. , and an inclined surface is provided on the block 41. Under the action of the inclined surface, when the pop-up rod 61 is reset, it will not be blocked by the block 41, so that the rake head 5 can periodically scatter the magnesium chloride hexaamine picked up by the rake head 5 under the rotation of the reciprocating tube 3, thereby improving the heating deammoniation efficiency of the magnesium chloride hexaamine; during the sliding process of the push rod 7, the third spring 72 is compressed. After the rake head 5 scatters the magnesium chloride hexaamine, under the reset action of the third spring 72, the push rod 7 can be better reset, and the engagement stability of the block 41 and the slot 63 is improved. At the same time, when the pop-up rod 61 is reset, the block 41 slides by abutting against the inclined surface, and is engaged with the slot 63 after sliding. When the block 41 slides, the push rod 7 will still slide through the cooperation of the inclined slot 42 and the round rod 71, and compress the third spring 72. When the block 41 is engaged with the slot 63, the third spring 72 pushes the push rod 7 to reset.

[0073] A first protrusion 31 is fixedly provided on the reciprocating tube 3, a fixed tube 8 is fixedly provided on the warehouse body 11, a reciprocating groove 81 is provided on the fixed tube 8, and the first protrusion 31 is slidably provided in the reciprocating groove 81. When the reciprocating tube 3 rotates along with the rotating shaft 2, under the cooperation of the first protrusion 31 and the reciprocating groove 81, the reciprocating tube 3 slides back and forth while rotating, so as to spread the magnesium hexachloroamine at the bottom of the warehouse body 11, prevent the magnesium hexachloroamine from accumulating at one place at the bottom of the warehouse body 11, which affects the heating effect of the magnesium hexachloroamine, and when the magnesium hexachloroamine is just added to the warehouse body 11, it is convenient to spread the magnesium hexachloroamine faster, thereby improving the heating efficiency of the magnesium hexachloroamine.

[0074] Working principle: When adding and deammoniating magnesium chloride hexammine, the magnesium chloride hexammine is put into the bin body 11, and then the rotating shaft 2 rotates, driving the reciprocating tube 3 to rotate. During the rotation of the reciprocating tube 3, under the action of the reciprocating groove 81 and the first protrusion 31, the reciprocating tube 3 slides back and forth at the same time, and drives the rake rod 4 and the rake head 5 to slide. In this process, the magnesium chloride hexammine in the bin body 11 can be spread out to avoid the magnesium chloride hexammine being concentrated below the feed port of the bin body 11, which affects the addition effect of the magnesium chloride hexammine.

[0075] As the reciprocating tube 3 rotates with the rotating shaft 2, the multiple cross bars 23 periodically pass through the arc rod 9, and slide relative to the rake rod 4 under the abutment of the arc rod 9. During the sliding process of the cross bar 23, the force storage rod 6 is pushed to slide on the rake rod 4 and the second spring 62 is compressed. In this process, the cross bar 23 abuts against the push rod 7 and pushes the push rod 7 to slide and compress the third spring 72. After the force storage rod 6 completes the compression of the second spring 62, the round rod 71 fixedly connected to the push rod 7 cooperates with the inclined groove 42, and the block 4 1 slides and disengages from the card slot 63. At this time, the pop-up rod 61 loses the restriction of the card block 41, and the second spring 62 is released to push the pop-up rod 61 to slide. When the spring rod slides, the second protrusion 64 cooperates with the spiral groove 51 to make the rake head 5 rotate half a circle, so that the magnesium hexaammine chloride scooped up on the rake head 5 is sprinkled out, so that the magnesium hexaammine chloride and the heat in the warehouse body 11 are further contacted, and the deammoniation efficiency of the magnesium hexaammine chloride is improved. After the cross bar 23 is separated from the arc rod 9, the reset force of the first spring 24 drives the power storage rod 6 and the pop-up rod 61 to slide and reset, and the rake head 5 to rotate and reset.

[0076] The above description is only by way of illustration of certain exemplary embodiments of the present invention. It is undoubted that those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A process for preparing electronic grade monosilane by magnesium silicide method, characterized in that: The process for preparing electronic grade monosilane by magnesium silicide method comprises the following steps: S1: silicon powder and magnesium powder are put into an alloy in a mass ratio of 1:1 to prepare a furnace, and the preparation is carried out at 500-600°C, and then the prepared silicon-magnesium alloy is put into an alloy crusher, crushed to 50-80 mesh, and mixed with dried ammonium chloride to generate a reaction raw material; S2: The reaction raw materials are put into a reactor and reacted in a liquid ammonia system to obtain reaction products such as monosilane, disilane, ammonia and hydrogen. The stirring speed of the reactor is 30-50r / min. S3: The process gas obtained by the reaction is introduced into an ammonia recovery tank, and the ammonia component in the process gas is recovered through a condenser device at the top of the ammonia recovery tank. S4: The crude process gas with the ammonia component is recovered and then passed through a purification device to adsorb the residual ammonia and impurities such as phosphine and arsine to obtain crude silane gas. S5: The crude silane gas passes through the top condenser of the distillation tower 1 to intercept the heavy components such as disilane, phosphine and arsine in the silane gas, allowing monosilane and light components such as hydrogen and nitrogen to enter the distillation tower 2. Then, by adjusting the temperature of the condenser of the second tower, the light components such as hydrogen and nitrogen are discharged from the top of the tower in the form of non-condensable steam. S6: After the receiving is completed, the kettle of the first distillation tower is heated, and the monosilane of the first distillation tower is distilled out at the top of the tower to the second distillation tower for the first distillation. S7: The monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower. When the pressure of the second distillation tower drops rapidly, the material transfer stage is considered to be completed. S8: Establish reflux in the three distillation towers and start discharging light components to obtain electronic grade monosilane. S9: After the reaction is completed, the by-product obtained by the reaction - magnesium chloride hexaamine is transferred to a rake dryer for heating and deammoniation. The gas phase is pressurized by a compressor and passed into a condenser for cooling and recovery of ammonia components. The rake dryer includes a spreading component, which is used to spread the magnesium chloride hexaamine while stirring it to increase its heating area.

2. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In step S3, the condenser is set at a temperature of -50 to -60°C. It can reduce the consumption of liquid ammonia and extend the time of purification device.

3. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In step S4, the air intake rate of the purification device is 10-30 kg / h.

4. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In the step S5, after the reaction in S5 stops, the monosilane receiving stage ends, the pressures of the first tower and the second tower are maintained at normal pressure, the condenser temperature of the first tower is -90±10°C, and the condenser temperature of the second tower is -130±10°C.

5. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In the step S6, the kettle temperature of the first distillation tower is evaporated to -60°C, and the first distillation is completed. The pressure of the first distillation tower is atmospheric pressure, and the condenser is set to a temperature of -110±10°C.

6. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In the step S7, the monosilane enriched in the kettle of the second distillation tower is transferred to the third distillation tower through a bottom pipe, so that heavy components such as disilane entrained in the first distillation or receiving stage can be removed.

7. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: In step S8, the three distillation towers are set up with full reflux for two hours.

8. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 1, characterized in that: The invention comprises a support (1), a warehouse body (11) is fixedly arranged on the support (1), a rotating shaft (2) is rotatably arranged on the warehouse body (11), a reciprocating tube (3) is slidably arranged on the rotating shaft (2), a rake rod (4) is fixedly arranged on the reciprocating tube (3), and a rake head (5) is rotatably arranged on the rake rod (4); The sprinkling assembly comprises a power storage rod (6) and an ejection rod (61) slidably arranged on the rake rod (4); a second spring (62) is arranged between the power storage rod (6) and the ejection rod (61); two ends of the second spring (62) are respectively fixedly connected to the power storage rod (6) and the ejection rod (61); a second convex block (64) is fixedly arranged on the ejection rod (61); a spiral groove (51) is arranged on the rake head (5); and the second convex block (64) is arranged in the spiral groove (51); It also includes a force storage component, which is used to make the force storage rod (6) slide and the second spring (62) compress during the rotation of the rotating shaft (2) to store force on the ejection rod (61); A release assembly is used to release the ejection rod (61) of the second spring (62) after the second spring (62) has completed compression.

9. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 8, characterized in that: The power storage assembly comprises a fixed ring (21) fixedly arranged on the rotating shaft (2), a telescopic block (22) is slidably arranged on the fixed ring (21), a cross bar (23) is fixedly arranged on the telescopic block (22), and the rake rod (4) and the power storage rod (6) are both slidably connected to the cross bar (23); A first spring (24) is provided between the telescopic block (22) and the fixing ring (21), and two ends of the first spring (24) are fixedly connected to the telescopic block (22) and the fixing ring (21) respectively; An arc-shaped rod (9) is fixedly arranged on the bin body (11), and the cross bar (23) abuts against the outer side surface of the arc-shaped rod (9).

10. The process for preparing electronic grade monosilane by magnesium silicide method according to claim 8, characterized in that: The release assembly comprises a block (41) slidably arranged on the rake rod (4), a slot (63) is arranged on the ejection rod (61), and the block (41) is engaged and connected with the slot (63); A push rod (7) is slidably arranged on the rake rod (4), a round rod (71) is fixedly arranged on the push rod (7), an inclined groove (42) is arranged on the pull block, and the round rod (71) is slidably arranged in the inclined groove (42); A third spring (72) is provided between the push rod (7) and the rake rod (4), and two ends of the third spring (72) are respectively fixedly connected to the push rod (7) and the rake rod (4), and the push rod (7) is in contact with the cross bar (23).

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