Device for improving hydrogen chloride absorption efficiency in sodium tetrachloroaluminate waste residue treatment

Abstract

The utility model discloses a device for improving hydrogen chloride absorption efficiency by treating sodium tetrachloroaluminate waste residues, relates to the technical field of treatment of by-products in synthesis of methyl phosphorus dichloride by an aluminum method, and aims to solve the problem of low hydrogen chloride absorption efficiency. The utility model provides a device capable of deepening the absorption degree of hydrogen chloride, continuously absorbing hydrogen chloride and continuously producing crystalline aluminum chloride. According to the utility model, the circulating pipelines are respectively arranged on the primary absorption kettle and the secondary absorption kettle, and the circulating pump and the hydrogen chloride gas inlet valve are arranged on the circulating pipelines, so that upper and lower media in the absorption kettles can be quickly exchanged and circulated; and hydrogen chloride gas is introduced in the aluminum-containing aqueous solution circulation process, and the hydrogen chloride gas and the aluminum-containing aqueous solution are in full contact in a circulation pipeline, so that the absorption effect is better, and the hydrogen chloride absorption efficiency is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of treatment of byproducts of methyl phosphorus dichloride synthesized by aluminum process, and in particular to a device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency. Background Art

[0002] In the process of synthesizing methylphosphonium dichloride by aluminum method which is currently widely used in China, the by-product is mainly sodium tetrachloroaluminate waste residue, which is large in amount. In the existing treatment method, it is mainly converted into polyaluminium chloride, aluminium hypophosphite, etc. The treatment of sodium tetrachloroaluminate waste residue requires dissolving the waste residue in a reactor with water, and then concentrating and centrifuging the sodium chloride therein, and the obtained centrifuged mother liquor is the aluminium-containing aqueous solution.

[0003] The phosphorus content in the waste residue has a great influence on the quality of the product, so it is necessary to remove the phosphorus element before subsequent treatment; in the process of removing the phosphorus element, the aluminum element can be converted into crystalline aluminum chloride. The simplest method is to use the common ion effect to precipitate crystalline aluminum chloride; this process involves allowing the system to absorb sufficient hydrogen chloride to achieve the purpose of increasing the chloride ion concentration. Under the ordinary absorption method, after the hydrogen chloride concentration reaches about 31%, the absorption efficiency is extremely low, and direct crystallization without further absorption, the crystallization rate of crystalline aluminum chloride is low, and the overall production efficiency is very low; after hydrogen chloride is absorbed, it enters the separation equipment for solid-liquid separation, the solid is crystalline aluminum chloride, and the liquid is a high-concentration hydrogen chloride solution containing various impurities.

[0004] In the process of treating the waste residue, the existing hydrogen chloride absorption technology uses a reactor + hydrogen chloride pipeline absorption, which is extremely inefficient. The introduction of hydrogen chloride absorption ultimately makes the hydrogen chloride concentration of the system reach 36%~37%, while the concentration of concentrated hydrochloric acid can generally only reach 36%~37%. After adding it to the aluminum-containing aqueous solution, the hydrogen chloride concentration of the entire system can only reach 31%~33% at most. At this concentration, the crystallization rate of crystalline aluminum chloride is less than 80%, which is a great loss. Therefore, it is necessary to increase the hydrogen chloride concentration of the system. Utility Model Content

[0005] Aiming at the problem of low hydrogen chloride absorption efficiency, the utility model provides a device which can deepen the hydrogen chloride absorption degree and realize continuous absorption of hydrogen chloride and continuous output of crystalline aluminum chloride.

[0006] In order to achieve the above-mentioned invention object, the technical solution of the utility model is as follows:

[0007] A device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency comprises an absorption kettle and a crystallization kettle, wherein the absorption kettle comprises a primary absorption kettle and a secondary absorption kettle, wherein the absorption kettles are respectively provided with a feed port and a circulation pipeline, wherein one end of the circulation pipeline is connected to the bottom of the absorption kettle body, and the other end is connected to the top of the reactor top, the circulation pipeline and the cavity of the absorption kettle form a loop, and a circulation pump and a hydrogen chloride gas inlet valve are provided on the circulation pipeline, the circulation pipeline of the primary absorption kettle is connected to the feed port of the second absorption kettle through a pipeline, the circulation pipeline of the secondary absorption kettle is connected to the feed port of the crystallization kettle through a pipeline, and the bottom of the crystallization kettle is connected to a crystallization separation device through a pipeline; the kettle bodies of the absorption kettle and the crystallization kettle are respectively provided with cooling devices; the cooling device is a jacket, the bottom of the jacket is provided with a cooling water inlet, and the top of the jacket is provided with a cooling water outlet.

[0008] Temperature detectors are respectively arranged in the cavities of the absorption kettle and the crystallization kettle.

[0009] The absorption kettle and the crystallization kettle are respectively provided with tail gas outlets; and the tail gas outlets are respectively connected with tail gas pipelines.

[0010] The circulation pipeline is provided with a venturi tube at the position of the hydrogen chloride gas inlet valve.

[0011] Valves are respectively provided at the connection between the circulation pipeline and the bottom of the absorption kettle, on the connecting pipeline between the circulation pipeline of the first absorption kettle and the second absorption kettle, on the connecting pipeline between the circulation pipeline of the second absorption kettle and the crystallization kettle, and on the connecting pipeline between the bottom of the crystallization kettle and the crystallization separation device; the valves are automatically controlled valves.

[0012] Liquid level gauges are respectively arranged in the cavities of the absorption kettle and the crystallization kettle.

[0013] Pressure sensors are respectively arranged in the cavities of the absorption kettle and the crystallization kettle.

[0014] The device for improving the absorption efficiency of hydrogen chloride also includes a PLC controller, which is electrically connected to the automatic control valve, the liquid level meter, the pressure sensor and the thermometer respectively.

[0015] Beneficial effects of the utility model:

[0016] 1. In the utility model, a certain level of treated aluminum-containing aqueous solution is pre-installed in the primary absorption kettle, and the primary circulation pump is turned on, and hydrogen chloride is mixed with the circulating liquid and absorbed; at the same time, the aluminum-containing aqueous solution is continuously introduced into the kettle at a certain speed through the main material pipeline, and after the kettle reaches a certain liquid level, the pipeline valve from the outlet of the primary circulation pump to the secondary absorption kettle is opened, and the material is transferred to the secondary absorption kettle at a certain speed. The material transfer process keeps the liquid level of the primary absorption kettle within a certain range; after the secondary absorption kettle starts to feed, after the kettle reaches a certain liquid level, the secondary circulation pump is turned on, and hydrogen chloride is mixed with the circulating liquid and absorbed. After the liquid level in the kettle reaches a certain level, open the pipeline valve from the outlet of the secondary circulation pump to the crystallization kettle, and transfer the material to the crystallizer at a certain speed. During the material transfer process, keep the liquid level of the secondary absorption kettle within a certain range; after the crystallization kettle starts to feed, after the material in the kettle reaches a certain level, continuously discharge the material out at a certain speed, and the material is transferred to the separation process to separate the crystallized aluminum chloride and mother liquor. When discharging the material, keep the liquid level in the kettle within a certain range to achieve continuous absorption of hydrogen chloride and continuous output of crystallized aluminum chloride.

[0017] 2. The utility model provides circulation pipelines in the primary absorption kettle and the secondary absorption kettle respectively, and provides a circulation pump and a hydrogen chloride gas introduction valve on the circulation pipeline. The utility model can quickly exchange and circulate the upper and lower layer media in the absorption kettle, and hydrogen chloride gas is introduced during the circulation of the aluminum-containing aqueous solution. The hydrogen chloride gas and the aluminum-containing aqueous solution are fully in contact in the circulation pipeline, so the absorption effect is better and the hydrogen chloride absorption efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the device for improving the absorption efficiency of hydrogen chloride according to the utility model.

[0019] 1. Primary absorption kettle; 2. Secondary absorption kettle; 3. Crystallization kettle; 4. Circulation pipeline; 5. Circulation pump; 6. Hydrogen chloride gas inlet valve; 7. Jacket; 8. Tail gas outlet; 9. Venturi tube. DETAILED DESCRIPTION

[0020] The present invention is further described in detail below in conjunction with the embodiments, but the implementation manner of the present invention is not limited thereto.

[0021] Example 1

[0022] This embodiment provides a Figure 1The device for improving the absorption efficiency of hydrogen chloride shown comprises an absorption kettle and a crystallization kettle 3, wherein the absorption kettle comprises a primary absorption kettle 1 and a secondary absorption kettle 2, wherein the absorption kettles are respectively provided with a feed port and a circulation pipeline 4, wherein one end of the circulation pipeline 4 is connected to the bottom of the absorption kettle body, and the other end is connected to the top of the reactor top, the circulation pipeline 4 and the cavity of the absorption kettle form a loop, and a circulation pump 5 and a hydrogen chloride gas inlet valve 6 are provided on the circulation pipeline 4, the circulation pipeline 4 of the primary absorption kettle 1 is connected to the feed port of the second absorption kettle through a pipeline, the circulation pipeline 4 of the secondary absorption kettle 2 is connected to the feed port of the crystallization kettle 3 through a pipeline, and the bottom of the crystallization kettle 3 is connected to the crystallization separation device through a pipeline;

[0023] The kettle bodies of the absorption kettle and the crystallization kettle 3 are respectively provided with cooling devices; the cooling device is a jacket 7, the bottom of the jacket 7 is provided with a cooling water inlet, and the top of the jacket 7 is provided with a cooling water outlet; the cavities of the absorption kettle and the crystallization kettle 3 are respectively provided with temperature detectors; valves are respectively provided at the connection between the circulation pipeline 4 and the bottom of the absorption kettle, on the connecting pipeline between the circulation pipeline 4 of the first absorption kettle and the second absorption kettle, on the connecting pipeline between the circulation pipeline 4 of the second absorption kettle and the crystallization kettle 3, and on the connecting pipeline between the bottom of the crystallization kettle 3 and the crystallization separation device.

[0024] In this embodiment, a certain level of treated aluminum-containing aqueous solution is pre-installed in the primary absorption kettle 1, and the circulating cooling water of the primary absorption kettle 1 is turned on to maintain the temperature in the kettle. After the temperature in the kettle reaches the required level, the primary circulation pump 5 and the valve on the circulation pipeline 4 and the hydrogen chloride introduction valve are turned on, and the hydrogen chloride is mixed with the circulating liquid in the circulation pipeline 4 and absorbed. At the same time, the aluminum-containing aqueous solution is continuously introduced into the kettle at a certain speed through the main material pipeline. After the kettle reaches a certain liquid level, the pipeline valve of the primary circulation pump 5 outlet to the secondary absorption kettle 2 is turned on, and the material is transferred to the secondary absorption kettle 2 at a certain speed. During the material transfer process, the liquid level of the primary absorption kettle 1 is kept within a certain range;

[0025] After the secondary absorption kettle 2 starts to feed, the circulating cooling water of the secondary absorption kettle 2 is turned on to maintain the temperature in the kettle. After a certain liquid level is reached in the kettle, the secondary circulation pump 5 and the valves on the circulation pipeline 4 and the hydrogen chloride inlet valve are turned on, and the hydrogen chloride is mixed and absorbed with the circulating liquid in the circulation pipeline 4. After a certain liquid level is reached in the kettle, the pipeline valve from the outlet of the secondary circulation pump 5 to the crystallization kettle 3 is turned on, and the material is transferred to the crystallization kettle at a certain speed. During the material transfer process, the liquid level of the secondary absorption kettle 2 is kept within a certain range;

[0026] After the crystallization kettle 3 starts feeding, the circulating cooling water is turned on to maintain the temperature in the kettle. When the material in the kettle reaches a certain liquid level, the bottom discharge valve is opened to continuously discharge the material at a certain speed, and the material is transferred to the separation process to separate the crystallized aluminum chloride and the mother liquor. When discharging the material, the liquid level in the kettle should be kept within a certain range.

[0027] Example 2

[0028] The present embodiment provides a device for treating sodium tetrachloroaluminate waste residue to improve the absorption efficiency of hydrogen chloride. The difference between the present embodiment and the embodiment 1 is that, in the present embodiment, the absorption kettle and the crystallization kettle 3 are respectively provided with tail gas outlets 8; the tail gas outlets 8 are respectively connected to tail gas pipelines; the circulation pipeline 4 is provided with a venturi tube 9 at the position of the hydrogen chloride gas inlet valve 6; and the remaining structure is the same as that of the embodiment 1.

[0029] In this embodiment, hydrogen chloride is mixed with the circulating liquid and absorbed through the venturi tube 9; the pressure difference between the gas phase inlet and the liquid phase outlet of the venturi tube 9 is used to make hydrogen chloride enter the venturi tube 9 and mix with the circulating liquid. Since the liquid flow rate inside the venturi tube 9 is extremely fast, the hydrogen chloride gas is dispersed by the liquid flow after entering the interior to form tiny bubbles, which increases the contact between hydrogen chloride and the liquid and strengthens the dissolution effect of hydrogen chloride. Because hydrogen chloride gas enters the kettle, and when the concentration of hydrogen chloride is high, a small amount of hydrogen chloride will escape from the material. Therefore, the absorption kettle and the crystallization kettle 3 are both provided with tail gas pipelines, which are the main component, namely hydrogen chloride. The tail gas is absorbed in turn through the water washing tower and the alkali washing tower. Prevent tail gas from entering the atmospheric environment and causing environmental incidents.

[0030] Example 3

[0031] Compared with Example 2, the present embodiment is different in that, in the present embodiment, the valves at the connection between the circulation pipeline and the bottom of the absorption kettle, on the connecting pipeline between the circulation pipeline of the first absorption kettle and the second absorption kettle, on the connecting pipeline between the circulation pipeline of the second absorption kettle and the crystallization kettle, and on the connecting pipeline between the bottom of the crystallization kettle and the crystallization separation device are automatic control valves; liquid level gauges are respectively provided in the cavities of the absorption kettle and the crystallization kettle 3; pressure sensors are respectively provided in the cavities of the absorption kettle and the crystallization kettle 3; the device for improving the absorption efficiency of hydrogen chloride also includes a PLC controller, and the PLC controller is electrically connected to the automatic control valve, the liquid level gauge, the pressure sensor and the thermometer, respectively.

[0032] In this embodiment, a PLC controller is electrically connected to the automatic control valve and the data sensor. The PLC controls the automatic control valve according to the data of the pressure sensor, the liquid level meter and the thermometer to realize the automatic operation of the device for treating sodium tetrachloroaluminate waste residue to improve the hydrogen chloride absorption efficiency.

[0033] It is understood that the present invention is described by some embodiments, and those skilled in the art are aware that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the scope of protection of the present invention.

Claims

1. A device for treating sodium tetrachloroaluminate waste residue to improve the absorption efficiency of hydrogen chloride, comprising an absorption kettle and a crystallization kettle (3), characterized in that: The absorption kettle comprises a primary absorption kettle (1) and a secondary absorption kettle (2), wherein the absorption kettles are respectively provided with a feed port and a circulation pipeline (4), wherein one end of the circulation pipeline (4) is connected to the bottom of the absorption kettle body, and the other end is connected to the top of the reactor top, the circulation pipeline (4) and the cavity of the absorption kettle form a loop, and the circulation pipeline (4) is provided with a circulation pump (5) and a hydrogen chloride gas inlet valve (6), the circulation pipeline (4) of the primary absorption kettle (1) is connected to the feed port of the second absorption kettle via a pipeline, the circulation pipeline (4) of the secondary absorption kettle (2) is connected to the feed port of the crystallization kettle (3) via a pipeline, and the bottom of the crystallization kettle (3) is connected to the crystallization separation device via a pipeline; the kettle bodies of the absorption kettle and the crystallization kettle (3) are respectively provided with cooling devices; the cooling device is a jacket (7), the bottom of the jacket (7) is provided with a cooling water inlet, and the top of the jacket (7) is provided with a cooling water outlet.

2. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 1, characterized in that: The absorption kettle and the crystallization kettle (3) are respectively provided with tail gas outlets (8); the tail gas outlets (8) are respectively connected to tail gas pipelines.

3. The device for improving the hydrogen chloride absorption efficiency by treating sodium tetrachloroaluminate waste residue according to claim 1, characterized in that: The circulation pipeline (4) is provided with a venturi tube (9) at the position of the hydrogen chloride gas inlet valve (6).

4. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 1, characterized in that: Automatic control valves are respectively provided at the connection between the circulation pipeline (4) and the bottom of the absorption kettle, on the connection pipeline between the circulation pipeline (4) of the first absorption kettle and the second absorption kettle, on the connection pipeline between the circulation pipeline (4) of the second absorption kettle and the crystallization kettle (3), and on the connection pipeline between the bottom of the crystallization kettle (3) and the crystallization separation device.

5. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 1, characterized in that: Temperature detectors are respectively arranged in the cavities of the absorption kettle and the crystallization kettle (3).

6. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 1, characterized in that: Liquid level gauges are respectively arranged in the cavities of the absorption kettle and the crystallization kettle (3).

7. The device for improving hydrogen chloride absorption efficiency by treating sodium tetrachloroaluminate waste residue according to claim 1, characterized in that: Pressure sensors are respectively arranged in the cavities of the absorption kettle and the crystallization kettle (3).

8. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 1, characterized in that: The device for improving hydrogen chloride absorption efficiency is also provided with a PLC controller.

9. The device for treating sodium tetrachloroaluminate waste residue to improve hydrogen chloride absorption efficiency according to claim 8, characterized in that: The PLC controller is electrically connected to the automatic control valve, the liquid level meter, the pressure sensor and the thermometer respectively.

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