A separation system for hexammine chloromagnesium from liquid ammonia

Abstract

The utility model discloses a kind of separation systems of magnesium hexacyanochloride and liquid ammonia, it is related to chemical separation technical field, and it includes: slurry storage tank, filter, liquid ammonia storage tank, first condensing unit, second condensing unit and drying unit;The inlet of filter is communicated with the outlet of slurry storage tank, and filter is equipped with liquid phase export, solid phase export and gas phase export;Liquid phase export is communicated with liquid ammonia storage tank, drying unit is set at solid phase export position, and gas phase export is sequentially communicated first condensing unit and second condensing unit.By the integrated design of gradient pressure filtration and two-stage condensation, the mixed slurry of magnesium hexacyanochloride and liquid ammonia is filtered by gradient pressure filtration, so as to separate the two;By the setting of two-stage condensation, the steam formed by liquid ammonia volatilization in filtration process can be condensed, the recovery rate of liquid ammonia is improved, the problems such as high energy consumption, solvent residue and equipment corrosion in prior art are avoided, and at the same time, the process flow is simplified.

Description

Technical Field

[0001] This utility model relates to the field of chemical separation technology, specifically a separation system for hexaammine magnesium chloride and liquid ammonia. Background Technology

[0002] In the process of preparing silane gas from silicon-magnesium alloy (Komatsu process), the bottom of the reactor contains a mixture of byproduct (hexaammine magnesium chloride) and liquid ammonia. This mixture needs to be separated, the liquid ammonia is recycled and reused, and the ammonia bound to magnesium chloride is further removed.

[0003] For example, the publication number CN211393878U, publication date September 1, 2020, entitled "System for Preparing Chlorosilanes Using Methylsilane," includes a reaction gas mixing device, a synthesis reaction device, a condensation device, and a separation device connected in sequence. The reaction gas mixing device includes a mixing container and a first heating device. The mixing container includes a container wall and a cavity formed by the container wall. A self-rotating agitator is movably disposed inside the cavity. The top of the mixing container is provided with a first air inlet and a second air inlet. The first air inlet is also connected to an air inlet pipe. The port of the air inlet pipe faces the agitator. The agitator can be driven to rotate by the airflow directed by the air inlet pipe. The reaction gas mixing device in the system provided by this utility model can fully mix hydrogen and methylchlorosilane and can keep the gas in the mixing container in a turbulent state so as not to deposit in the mixing container.

[0004] In existing technologies such as those containing the aforementioned patents, solvent extraction or high-temperature decomposition methods, as well as conventional filtration methods, are commonly used. However, solvent extraction or high-temperature decomposition methods have problems such as high energy consumption, solvent residue, and equipment corrosion. Conventional filtration methods are prone to high moisture content in solid magnesium hexaammine chloride due to liquid ammonia residue, requiring additional equipment for drying steps, making the process complex. Utility Model Content

[0005] The purpose of this invention is to provide a separation system for hexaammine magnesium chloride and liquid ammonia to address the shortcomings of the prior art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a separation system for hexaammine magnesium chloride and liquid ammonia, comprising: a slurry storage tank, a filter, a liquid ammonia storage tank, a first condensation unit, a second condensation unit, and a drying unit;

[0007] The filter inlet is connected to the outlet of the slurry storage tank, and the filter has a liquid phase outlet, a solid phase outlet, and a gas phase outlet.

[0008] The liquid phase outlet is connected to the liquid ammonia storage tank, the drying unit is located at the solid phase outlet, and the gas phase outlet is connected to the first condensation unit and the second condensation unit in sequence.

[0009] Furthermore, the filter incorporates multiple pressure chambers to achieve gradient pressure filtration.

[0010] Furthermore, a gas phase buffer tank is provided between the gas phase outlet and the first condensation unit, and a bag filter is provided at the end of the gas phase buffer tank.

[0011] Furthermore, a valve is installed at the outlet of the slurry storage tank.

[0012] Furthermore, a transfer pump is installed between the valve and the filter.

[0013] Furthermore, a check valve is installed between the second condensation unit and the liquid ammonia storage tank.

[0014] Compared with existing technologies, the present invention provides a separation system for hexaammine magnesium chloride and liquid ammonia. Through the integrated design of gradient pressure filtration and two-stage condensation, the gradient pressure filtration separates the mixed slurry of hexaammine magnesium chloride and liquid ammonia. The two-stage condensation can condense the vapor formed by the volatilization of liquid ammonia during the filtration process, thereby improving the recovery rate of liquid ammonia and avoiding the problems of high energy consumption, solvent residue, and equipment corrosion in existing technologies. At the same time, it simplifies the process flow. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings.

[0016] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present utility model.

[0017] 1. Slurry storage tank; 2. Filter; 3. Liquid ammonia storage tank; 4. Gas phase buffer tank; 5. Bag filter; 6. First condensing unit; 7. Second condensing unit; 8. Drying unit; 9. Valves; 10. Transfer pump; 11. Check valve. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0019] Please see Figure 1This utility model provides a separation system for hexaammine magnesium chloride and liquid ammonia, comprising:

[0020] A separation system for hexaammine magnesium chloride and liquid ammonia includes: a slurry storage tank 1, a filter 2, a liquid ammonia storage tank 3, a first condensation unit 6, a second condensation unit 7, and a drying unit 8.

[0021] Preferably, the slurry storage tank 1 is equipped with an electric stirring rod, which can stir the slurry and disperse it evenly through the stirring device to ensure the slurry's fluidity and stability.

[0022] Specifically, a valve 9 is installed at the outlet of the slurry storage tank 1; more specifically, a transfer pump 10 is installed between the valve 9 and the filter 2; the transfer pump 10 is used to transport the slurry into the filter 2 for filtration.

[0023] The filter 2 is equipped with multiple pressure chambers to achieve gradient pressure filtration, allowing liquid ammonia to penetrate the filter membrane under pressure, while solid hexaammine magnesium chloride is retained to form a filter cake; the pressure range is between 0.1-0.5 MPa.

[0024] After filtration, the magnesium hexaammine chloride is a wet solid. Before the drying process, its moisture content is 4.2%, and it is dried by drying unit 8.

[0025] More specifically, the filtration conditions are: pressure 0.3MPa, temperature -20℃; the filter membrane is a ceramic microporous membrane with a filtration accuracy ≤1μm and a filtration rate of 8m³ / h; in this embodiment, the pore size is 0.5μm, and the filter membrane can withstand a liquid ammonia environment of -50℃ to avoid embrittlement of the filter material.

[0026] Understandable: The inlet of filter 2 is connected to the outlet of slurry storage tank 1. Filter 2 has a liquid phase outlet, a solid phase outlet and a gas phase outlet. These three outlets correspond to the outlet of liquid ammonia after filtration, the outlet of solid hexaammine magnesium chloride produced after filtration, and the outlet of liquid ammonia produced during filtration volatilizing into vapor.

[0027] The liquid phase outlet is connected to the liquid ammonia storage tank 3, the drying unit 8 is located at the solid phase outlet, and the gas phase outlet is connected in sequence to the first condensation unit 6 and the second condensation unit 7.

[0028] Specifically, a gas phase buffer tank 4 is provided between the gas phase outlet and the first condensation unit 6, and a bag filter 5 is provided at the end of the gas phase buffer tank 4; more specifically, the bag filter 5 is provided between the gas phase buffer tank 4 and the first condensation unit 6; by providing the bag filter 5 at the opening of the gas phase buffer tank 4, solid particles can be intercepted.

[0029] Among them, drying unit 8 adopts a twin-shaft paddle dryer with a dryer speed of 5 rpm and an inclination angle of 10°. The residence time of the solid material of hexaammine magnesium chloride in the drying unit is 30 minutes. After drying, the moisture content of the solid hexaammine magnesium chloride is 0.3%.

[0030] Specifically, the drying unit uses a heat transfer oil circulation heating method. In the drying process of hexaammine magnesium chloride, the heating temperature is 40℃-60℃. After drying is completed, a deep deammoniation process is required, and the heating temperature for deep deammoniation is 150℃.

[0031] A check valve 11 is provided between the second condensation unit 7 and the liquid ammonia storage tank 3. The function of the check valve 11 is to restrict the liquid ammonia that has been condensed by the second condensation unit 7 to flow into the liquid ammonia storage tank 3, while the liquid ammonia in the liquid ammonia storage tank 3 cannot flow towards the second condensation unit 7 through the check valve 11.

[0032] When using it, follow these steps:

[0033] Step 1: Slurry pretreatment. The mixture of magnesium hexaammine chloride and liquid ammonia is evenly dispersed using a stirring device to ensure the slurry's fluidity and stability.

[0034] Step 2: Filtration. Filter the well-stirred slurry and collect the filtered liquid nitrogen into a liquid nitrogen storage tank.

[0035] Step 3: Initial condensation. The ammonia vapor that evaporates during the filtration process is introduced into the first condensation unit 6 and condensed through a circulating water condenser to recover most of the liquid ammonia.

[0036] Step 4: Secondary condensation. The ammonia vapor that was not condensed in Step 3 is introduced into the second condensation unit 7 for secondary condensation. The second condensation unit is a dichloromethane condenser, which is used to condense the remaining ammonia vapor that was not completed in Step 3.

[0037] Steps three and four are for condensing and collecting the liquid nitrogen vapor formed by the volatilization of liquid nitrogen, which improves the recovery rate of liquid nitrogen to a certain extent; the recovery rate of liquid nitrogen is over 98%.

[0038] Step 5: Preliminary drying. The filtered solid hexaammine magnesium chloride is fed into drying unit 8 for drying. The heating temperature of drying unit 8 is 40℃-60℃.

[0039] Step 6: Deep deammoniation. The drying temperature of drying unit 8 is increased to 150°C to remove the complexed ammonia in hexaammine magnesium chloride.

[0040] Preferably, during the drying process, inert gases such as nitrogen can be introduced as protective gases to inhibit the decomposition of hexaammine magnesium chloride and the generation of organic impurities, thus ensuring product purity.

[0041] The foregoing description only illustrates certain exemplary embodiments of the present invention. Undoubtedly, 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 system for separating hexammine chloromagnesium from liquid ammonia, characterized in that, include: Slurry storage tank (1), filter (2), liquid ammonia storage tank (3), first condensation unit (6), second condensation unit (7) and drying unit (8); The inlet of the filter (2) is connected to the outlet of the slurry storage tank (1), and the filter (2) has a liquid phase outlet, a solid phase outlet and a gas phase outlet; The liquid phase outlet is connected to the liquid ammonia storage tank (3), the drying unit (8) is located at the solid phase outlet, and the gas phase outlet is connected to the first condensation unit (6) and the second condensation unit (7) in sequence.

2. The system for separating magnesium chloride hexammoniate from liquid ammonia according to claim 1, wherein The filter (2) is equipped with multiple pressure chambers to achieve gradient pressure filtration.

3. The system for separating magnesium chloride hexammoniate from liquid ammonia according to claim 1, wherein A gas phase buffer tank (4) is provided between the gas phase outlet and the first condensation unit (6), and a bag filter (5) is provided at the end of the gas phase buffer tank (4).

4. The system for separating magnesium chloride hexammoniate from liquid ammonia according to claim 1, wherein A valve (9) is installed at the outlet of the slurry storage tank (1).

5. The system for separating magnesium chloride hexammoniate from liquid ammonia according to claim 4, wherein A delivery pump (10) is installed between the valve (9) and the filter (2).

6. The system for separating magnesium chloride hexammoniate from liquid ammonia according to claim 1, wherein A check valve (11) is provided between the second condensation unit (7) and the liquid ammonia storage tank (3).

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