CN217733291U

CN217733291U - System capable of dechlorinating sodium aluminate solution

Info

Publication number: CN217733291U
Application number: CN202220749790.3U
Authority: CN
Inventors: 徐勇智
Original assignee: Individual
Current assignee: Individual
Priority date: 2022-04-02
Filing date: 2022-04-02
Publication date: 2022-11-04
Anticipated expiration: 2032-04-02

Abstract

The utility model relates to the technical field of metallurgy and chemical engineering, in particular to a system capable of dechlorinating sodium aluminate solution, which comprises a reduction device, an electrolysis device connected with the output end of the reduction device, and a gas treatment device connected with a gas discharge end connected with the electrolysis device; the reduction device comprises a microwave heating and stirring reaction cylinder provided with a liquid inlet; the electrolytic device comprises a tank body connected with the reduction device, at least one electrolytic tank which is arranged in the tank body and is provided with an anode area and a cathode area, an anode plate which is arranged in the anode area of the electrolytic tank, a cathode plate which is arranged in the cathode area of the electrolytic tank, a cation exchange membrane which is arranged between the anode area and the cathode area, and an exhaust port which is arranged at the top of the tank body and is used for exhausting gas generated by electrolysis. The utility model discloses make the production technology of sodium aluminate solution dechlorination more high-efficient, low energy, environmental protection.

Description

System capable of dechlorinating sodium aluminate solution

Technical Field

The utility model relates to a metallurgical chemical industry technical field especially relates to a system that enables dechlorination of sodium aluminate solution.

Background

Aluminum is a silver-white metal, lightweight, and has good ductility, electrical conductivity, thermal conductivity, heat resistance, and radiation resistance. The aluminum generates a compact oxide film on the surface in the air, so that the aluminum has good corrosion resistance. Aluminum and aluminum alloys are one of the most economically feasible materials with a wide range of applications. The current production and usage of aluminium (in tons) is second only to steel, becoming the second largest metal for human use; and the resources of the aluminum are abundant, and the mineral storage capacity of the aluminum accounts for more than 8 percent of crust-forming substances. China has the first global aluminum yield and productivity. The only method for producing metallic aluminum is electrolytic method using alumina as raw material. The production method of the aluminum comprises the following steps: the method comprises the following steps of aluminum ore mining, aluminum oxide preparation, electrolytic aluminum smelting and aluminum processing production.

The Bayer process is adopted to produce alumina in most foreign countries, and China combines the resource situation of the China, initiates the Bayer-sintering hybrid process, and greatly improves the total recovery rate of the alumina. With the continuous improvement of production technology, some new production methods such as lime bayer process, ore dressing bayer process and the like are continuously applied to production. In the production process of aluminum oxide, aluminum ash generated in the production of electrolytic aluminum returns to a production system, chlorine-containing impurities are brought in, and the chlorine-containing impurities are continuously enriched and increased, so that the product granularity is finer, the product quality is influenced, the equipment corrosion is increased, and the aluminum ash becomes a historical problem in the electrolytic aluminum industry.

In the existing dechlorination method of the alkaline solution, chloride ions in the solution are mostly removed by adopting an ultrahigh lime-aluminum method, calcium oxide and sodium metaaluminate are added into chlorine-containing wastewater to generate a calcium-aluminum-chloride compound Ca4Al2Cl2 (OH) 12 with extremely low solubility, so that the effect of removing the chloride ions is further achieved, but in the sodium metaaluminate solution, due to the existence of a large amount of aluminum ions, a reverse-dissolved calcium-aluminum-chloride compound Ca4Al2Cl2 (OH) 12 is generated, the precipitation is extremely little, and the purpose of separating and removing the chloride ions cannot be achieved.

Disclosure of Invention

The features and advantages of the present invention are set forth in part in the description which follows, or may be obvious from the description, or may be learned by practice of the invention.

In order to overcome the problems of the prior art, the utility model aims to provide a system which can dechlorinate the sodium aluminate solution with high efficiency, low energy and environmental protection.

In order to achieve the above purpose, the utility model provides a technical scheme is:

a system capable of dechlorinating sodium aluminate solution is characterized by comprising a reduction device, an electrolysis device connected with the output end of the reduction device, and a gas treatment device connected with the gas discharge end connected with the electrolysis device;

the reduction device comprises a microwave heating and stirring reaction cylinder provided with a liquid inlet;

the electrolytic device comprises a tank body connected with the reduction device, at least one electrolytic tank arranged in the tank body and provided with an anode region and a cathode region, at least one anode plate arranged in the anode region of the electrolytic tank, at least one cathode plate arranged in the cathode region of the electrolytic tank, a cation exchange membrane arranged between the anode region and the cathode region, a first liquid inlet and a first liquid outlet which are arranged on the tank body and communicated with the anode region, a second liquid inlet and a second liquid outlet which are arranged on the tank body and communicated with the cathode region, and an exhaust port which is arranged at the top of the tank body and used for exhausting gas generated by electrolysis;

the gas treatment device comprises an air draft cover arranged above the tank body, a leaching mechanism arranged on the downstream side of the gas flow direction and used for collecting chlorine gas, and a gas purification mechanism connected with the leaching mechanism.

Preferably, the electrolysis apparatus further comprises a first circulation pump for circulating the anolyte within the anodic zone.

Preferably, the electrolysis device further comprises a high-level storage tank for the liquid before electrolysis, which is arranged between the reduction device and the tank body.

Preferably, an anolyte storage tank is arranged between the first circulating pump and the tank body; and the output end of the anolyte storage tank is provided with a valve for controlling the communication with the input end of the high-level liquid storage tank or the second liquid inlet of the pre-electrolysis liquid.

Preferably, the leaching mechanism comprises at least two leaching towers connected in sequence, an alkali liquor distribution tank connected with the input end of the leaching tower and connected through a pipeline, an alkali liquor pump for pumping alkali liquor into the leaching tower, an alkali liquor distribution valve for controlling the communication between the alkali liquor distribution tank and the leaching tower, at least one second circulating pump connected with the two adjacent leaching towers, and a sodium hypochlorite product storage tank connected with the output end of the leaching tower; and the absorption liquid in the leaching tower is sodium hydroxide.

Preferably, the gas purification mechanism comprises an exhaust fan connected with the leaching mechanism, and a lime pit arranged on the downstream side of the gas flow direction and connected with the exhaust fan through a pipeline.

Preferably, the device also comprises a filter press arranged between the reduction device and the electrolysis device;

and/or; the reducing agent added into the microwave heating stirring reaction cylinder is aluminum powder.

Preferably, the exhaust hood is provided with a hydrogen online detection mechanism.

Preferably, the electrolysis device further comprises at least one of the following arrangements:

the anode plate is made of a corrosion-resistant plate; one of graphite, titanium or noble metal is coated on the corrosion-resistant plate;

the cathode plate is one of a nickel plate, a stainless steel plate or a low-carbon steel plate;

the depth of the anode plate and the cathode plate inserted into the electrolyte is 20-40 cm;

the number of the anode regions and the number of the cathode regions are at least one;

the first liquid outlet of the anode region is connected with the input end of the anolyte storage tank;

and the second liquid outlet is connected with a sodium aluminate product storage tank.

Preferably, the system also comprises a PLC controller for controlling the automatic operation of the whole system.

The utility model has the advantages that:

the utility model has the advantages of high efficiency, low energy and environmental protection, and simultaneously, chloride ions in the bauxite leaching solution or the sodium aluminate concentrated mother liquor solution are directly separated out in the mode of chlorine gas through electrolysis, so that the required power consumption is lower, and the process belongs to the process with low energy consumption; the reduction device is used for reducing the solids such as heavy metals in the bauxite leaching solution or the sodium aluminate concentrated mother liquor solution, and the solids can be directly sold to relevant smelting plants in a concentrated manner after being filtered, so that the business income of the plants is increased, and the heavy metals are prevented from being separated out from the cathode in the electrolytic process to block a cation exchange membrane; meanwhile, the reducing agent added in the reduction process is aluminum powder, so that the reducing agent can react with sodium hydroxide in the subsequent leaching process to generate sodium metaaluminate, and the quality of alumina production products cannot be influenced in the subsequent processing. The reduction device adopts a microwave heating stirring reaction cylinder, and belongs to a process with low energy consumption compared with the traditional smelting process.

Because the cation exchange membrane is adopted, the solution after the anode electrolysis is continuously used as the electrolyte of the cathode, the chloride ions in the anode region and the hydroxyl ions in the cathode region can not move freely, so that the concentration of the chloride ions in the anode region is higher, the separation of the chloride ions during electrolysis is further facilitated, and the concentration of free alkali in the electrolyte of the cathode region is obviously increased, so that the consumption of aluminum oxide can be reduced and the production cost can be reduced in the subsequent bauxite processing process of the sodium aluminate solution.

In order to improve dechlorination rate and reduce the absorption of the separated chlorine gas by the electrolyte, the cathode and the anode of electrolysis are multiple cathodes and anodes which are shallow in the electrolyte, and the current density of electrolysis is ensured.

The electrolyzer is designed to adopt a plate-frame structure, so that the layout is more reasonable, the occupied area is small, and the equipment investment is saved.

Accurately judging the concentration of hydrogen by using a hydrogen online detection device; because the air draft cover in the system is provided with the large-flow variable-frequency air draft fan, when the concentration of hydrogen exceeds a preset value, the concentration of gas generated by electrolysis can be controlled by controlling the air draft amount, and explosion is avoided.

Because the amount of the treated gas is large, the multistage leaching tower is adopted to absorb chlorine, and a sodium hydroxide solution is added into the leaching tower to absorb the chlorine, so that a byproduct of disinfectant, namely sodium hypochlorite can be obtained, the product income is increased, and the gas can be discharged after reaching the standard after being absorbed by a lime pool, so that the pollution is reduced.

Drawings

The advantages and the manner of realisation of the invention will become more apparent hereinafter by describing in detail, by way of example, with reference to the accompanying drawings, wherein the content shown in the drawings is only intended for the purpose of illustrating the invention, and does not constitute any significant limitation thereof, in which:

fig. 1 is a schematic diagram of a system for dechlorinating a sodium aluminate solution according to an embodiment of the present invention.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified; the terms "upper", "lower", "inner", "outer", "top", "bottom", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and therefore should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Detailed description of the preferred embodiment 1

As shown in figure 1, the bauxite leaching solution is treated by the system which can dechlorinate the sodium aluminate solution and is provided by the utility model, the total alkali (the content of the alkalis and the carbon alkali) of the bauxite leaching solution is 290-315 g/l, and the chloride ion content is 3-20 g/l; the system capable of dechlorinating the sodium aluminate solution comprises a reduction device, an electrolysis device 8 connected with the output end of the reduction device, and a gas treatment device connected with a gas discharge end connected with the electrolysis device 8;

the reduction device comprises a microwave heating and stirring reaction cylinder 1 provided with a liquid inlet; in the embodiment, a 1 cubic meter microwave heating and stirring reaction cylinder 1 is adopted, wherein aluminum powder is adopted as a reducing agent in the microwave heating and stirring reaction cylinder 1, the adding amount is 500-1000 g/L, the reducing temperature is 55-70 ℃, and the reducing time is 30-45 minutes;

the electrolytic device 8 comprises a tank body connected with the reduction device, at least one electrolytic tank arranged in the tank body and provided with an anode region and a cathode region, at least one anode plate 22 arranged in the anode region of the electrolytic tank, at least one cathode plate 23 arranged in the cathode region of the electrolytic tank, a cation exchange membrane 15 arranged between the anode region and the cathode region, a first liquid inlet and a first liquid outlet which are arranged on the tank body and communicated with the anode region, a second liquid inlet and a second liquid outlet which are arranged on the tank body and communicated with the cathode region, and an exhaust port which is arranged at the top of the tank body and used for exhausting gas generated by electrolysis; the number of the anode regions and the number of the cathode regions are at least one, and the number can be set according to actual production requirements. The electrolytic device 8 also comprises a liquid high-level storage tank 6 before electrolysis, which is arranged between the reduction device and the tank body and is used for storing the reduced solution. An anode solution inlet valve 7 is arranged between the output end of the high-level liquid storage tank 6 before electrolysis and the tank body. In this embodiment, set up an electrolysis trough in the cell body, the volume of this electrolysis trough is 480 liters, has set up 8 negative pole districts and 9 positive polar regions, and every positive polar region sets up 10 anode plates, and every negative pole district sets up 5 negative plates, the bottom of cell body is located to the first inlet of positive polar region, and this first inlet is connected with the output of this liquid high-order storage tank 6 before the electrolysis, the top of cell body is located to the first liquid outlet of positive polar region. The depth of the anode plate 22 and the cathode plate 23 inserted into the electrolyte is 20-40 cm, so as to effectively reduce the amount of chlorine absorbed by the alkali liquor and fully separate out the chlorine in the electrolyte. The anode plate 22 and the cathode plate 23 have a shorter appearance compared to the conventional electrolytic plates. The short electrolysis electrode plates are adopted, so that the appearance of the electrolysis device 8 is short.

The gas treatment device comprises an air draft cover 11 arranged above the tank body, a leaching mechanism arranged on the downstream side of the gas flow direction and used for collecting chlorine gas, and a gas purification mechanism connected with the leaching mechanism. The generated gas is prevented from diffusing through the air draft cover 11, the pollution of the gas to the environment is prevented, the generated gas is sent to the leaching mechanism in time for leaching, and the danger of gas aggregation is prevented. The exhaust hood 11 includes a hood body disposed above the tank body, and a large-flow variable-frequency exhaust fan disposed on the hood body.

In this embodiment, the opening and closing of each valve and the starting and closing of each device are performed manually, which is not described herein.

Further, the electrolysis device 8 also comprises a first circulation pump 13 for circulating the anolyte in the anode region. As a preferred embodiment, the first circulation pump 13 is disposed between the first liquid inlet and the first liquid outlet, so as to sufficiently electrolyze the solution in the anode region, and further sufficiently remove chlorine. In this embodiment, the circulation flow rate of the solution in the anode region is controlled to be 8 liters/minute by the first circulation pump 13.

Further, an anolyte storage tank 12 is arranged between the first circulating pump 13 and the tank body and used for storing electrolyzed anode area solution which is sodium aluminate solution from which chlorine has been effectively removed; and the output end of the anolyte storage tank 12 is provided with a control valve 14 which is used for controlling the communication with the input end of the pre-electrolysis liquid high-level storage tank 6 or the second liquid inlet. The first outlet of the anode region is connected to the input of the anolyte reservoir 12. The second liquid outlet is connected to a sodium aluminate product storage tank 16. The alkalinity of the sodium aluminate solution can be improved by the way of circularly feeding the sodium aluminate solution in the anolyte storage tank 12 into the cathode region for continuous electrolysis, so that the addition of alkali liquor in the subsequent smelting and processing can be reduced, and the processing cost of subsequent products can be reduced.

Further, the leaching mechanism comprises at least two leaching towers connected in sequence, an alkali liquor preparation tank 27 connected with the input ends of the leaching towers through pipelines, an alkali liquor preparation pump 26 for pumping alkali liquor to the leaching towers, an alkali liquor preparation valve 25 for controlling the communication between the alkali liquor preparation tank 27 and the leaching towers, at least one second circulating pump 24 connected with two adjacent leaching towers, and a sodium hypochlorite product storage tank 28 connected with the output ends of the leaching towers; and the absorption liquid in the leaching tower is sodium hydroxide. And the sodium hypochlorite product storage tank 28 and the output end of the leaching tower are provided with a third circulating pump 21. In this embodiment, a second-stage leaching is adopted, that is, 2 leaching towers connected in sequence are included, when the device is actually used, clear water is added into a solution preparation alkali tank, sodium hydroxide is added according to a proportion of 10%, the sodium hydroxide is stirred and dissolved, an alkali preparation valve 25 is opened, an alkali preparation pump 26 is started, prepared alkali liquor is pumped into a second-stage leaching tower 18, a second circulating pump 24 is started, the alkali liquor in the second-stage leaching tower 18 is pumped into a first-stage leaching tower 17, a leaching switch 19 of the leaching tower is started, leaching of electrolyzed gas is started, when the pH value of the solution in the second-stage leaching tower 18 reaches 10, the second-stage leaching tower 18 is closed, dechlorination is performed so as to replace concentrated solution of the hydrogen hydroxide, a third circulating pump 21 is started at the same time, the solution in the first-stage leaching tower 17 is pumped into a sodium hypochlorite storage tank 28, and then the solution in the second-stage leaching tower 18 is pumped into the first-stage leaching tower 17.

Further, the gas purification mechanism comprises an exhaust fan 29 connected with the leaching mechanism, and a lime pit 20 arranged at the downstream side of the gas flow direction and connected with the exhaust fan 29 through a pipeline. The blower 29 is a large flow blower.

Further, be equipped with hydrogen on-line measuring mechanism on the aspirator 11 to in time survey the content of the hydrogen in the gas that produces after the electrolysis, when hydrogen content is higher than the default, through the amount of wind of increase aspirator 11 to and the gas outgoing who will produce in time, prevent that hydrogen content is too high, the explosion takes place. This hydrogen on-line measuring mechanism includes hydrogen on-line measuring analyzer 9 to and at least one probe 10 of locating on the aspirator 11 inner wall, to great electrolytic device 8, can improve the accuracy to hydrogen detection through the settlement of a plurality of probes 10, consequently, can set for according to actual production needs, does not restrict here.

Further, the anode plate 22 is made of corrosion-resistant plate material; the corrosion-resistant plate is coated with one of graphite, titanium or noble metal. The noble metal includes ruthenium, iridium, etc., and is not particularly limited herein.

Further, the cathode plate 23 is one of a nickel plate, a stainless steel plate, or a low carbon steel plate.

After the dechlorination treatment of the sodium aluminate concentrated mother liquor by the system, the total alkali (available alkali + carbon alkali) content of the sodium aluminate solution in the anolyte storage tank 12 is 305.1 g/l and the chloride ion content is 0.88 g/l. While the sodium aluminate solution in the sodium aluminate product tank 16 has a total soda (kolkali + soda) content of 330.8 g/l and a chloride ion content of 0.86 g/l. And the actual production requirement is met.

In conclusion, the system capable of dechlorinating the sodium aluminate solution has the advantages of high efficiency, low energy and environmental protection, and simultaneously, chloride ions in the solution are directly separated out in a chlorine gas mode through electrolysis, so that the required power consumption is low, and the process belongs to a low-energy-consumption process; the reduction device is used for reducing solids such as heavy metals in the bauxite leaching solution, and the solids can be directly sold to relevant smelting plants in a concentrated manner after being filtered, so that the business income of the plants is increased, and the heavy metals are prevented from being separated out from the cathode in the electrolytic process to block the cation exchange membrane 15; meanwhile, the reducing agent added in the reduction process is aluminum powder, so that the reducing agent can react with sodium hydroxide in the subsequent leaching process to generate sodium metaaluminate, and the quality of alumina production products cannot be influenced in the subsequent processing. The reduction device adopts the microwave heating stirring reaction cylinder 1, and belongs to a process with low energy consumption compared with the traditional smelting process.

Because the cation exchange membrane 15 is adopted, the solution after the anode electrolysis is continuously used as the electrolyte of the cathode, the chloride ions in the anode area and the hydroxyl ions in the cathode area can not move freely, so that the concentration of the chloride ions in the anode area is higher, the chloride ions can be separated out during electrolysis, and the concentration of free alkali in the electrolyte in the cathode area is obviously increased, so that the consumption of aluminum oxide can be reduced and the production cost can be reduced in the subsequent bauxite processing process of the sodium aluminate solution.

The electrolysis device 8 adopts a plate-frame structure, so that the layout is more reasonable, the occupied area is small, and the equipment investment is saved.

Accurately judging the concentration of hydrogen by using a hydrogen online detection device; because the variable-frequency exhaust fan with large flow rate is arranged in the exhaust hood 11 in the system, when the concentration of hydrogen exceeds a preset value, the concentration of gas generated by electrolysis can be controlled by controlling the exhaust amount, and explosion is avoided.

Because the amount of the treated gas is large, the multistage leaching tower is adopted to absorb chlorine, and a sodium hydroxide solution is added into the leaching tower to absorb the chlorine, so that a byproduct of disinfectant, namely sodium hypochlorite can be obtained, the product income is increased, and the gas can be discharged after reaching the standard after being absorbed by the lime pool 20, so that the pollution is reduced.

Specific example 2

This example also provides a system for dechlorinating a sodium aluminate solution, which has a structure substantially the same as that of example 1 except that:

the sodium aluminate concentrated mother liquor is treated in the embodiment, and the total alkali (alkalescent plus carbon alkali) content in the concentrated mother liquor is 290-320 g/L, and the chloride ion content is 3-20 g/L. The system in the embodiment also comprises a filter press 5 arranged between the reduction device and the electrolysis device 8, so that the solids such as heavy metals and the like reduced from the sodium aluminate concentrated mother liquor can be conveniently filtered out, the cation exchange membrane 15 in the electrolysis device 8 is prevented from being blocked, the filtered solids such as heavy metals and the like can be directly collected and sold to relevant smelting plants, and the business income of the plants is increased. A discharge valve 3 of the microwave reaction cylinder and a filter pump 4 are arranged between the filter press 5 and the microwave heating stirring reaction cylinder 1.

Further, the automatic stirring device also comprises a PLC controller for controlling the whole system to automatically operate and a microwave power supply controller 2 for controlling the microwave heating stirring reaction cylinder 1, so that the labor intensity of operators on a production line is reduced, the influence of misoperation of the operators on production line products is reduced, the automation of the production line is improved, and the production efficiency is improved.

Further, the various types of valves in this embodiment all use electromagnetic valves, such as a discharge valve, a liquid inlet valve, a control valve, and the like, which are not listed here.

After the dechlorination treatment of the sodium aluminate concentrated mother liquor by the system, the total alkali (available alkali + carbon alkali) content of the sodium aluminate solution in the anolyte storage tank 12 is 301.5 g/l and the chloride ion content is 0.92 g/l. The sodium aluminate solution in the sodium aluminate product tank 16 has a total soda content of 332.8 g/l and chloride ions of 0.91 g/l. The actual production requirement is met.

The utility model discloses what protect is holistic sodium aluminate solution dechlorination system's structural design to do not relate to the improvement to the procedure, the PLC controller is very easy to be realized to each valve, circulating pump, air exhauster 29 and the control program of each type valve, and the technical personnel in the field can all utilize PLC basic knowledge to design PLC control program under the designing requirement of learning the motion stroke.

In summary, compared with embodiment 1, this embodiment can not only achieve the technical effect of embodiment 1, but also reduce the blockage of the cation exchange membrane 15 due to the arrangement of the filter press 5 and the PLC controller, thereby improving the electrolysis efficiency, and at the same time, due to the arrangement of the PLC controller, the labor intensity of the operator on the production line is reduced, the influence of misoperation on the production line is reduced, the automation of the production line is improved, and the production efficiency is improved.

The preferred embodiments of the present invention have been described with reference to the accompanying drawings, and those skilled in the art can implement the present invention in various modifications without departing from the scope and spirit of the present invention. For instance, features illustrated or described as part of one embodiment, can be used with another embodiment to yield a still further embodiment. The above description is only a preferred and practical embodiment of the present invention, and is not intended to limit the scope of the present invention, and all equivalent variations using the contents of the present specification and the accompanying drawings are included in the scope of the present invention.

Claims

1. A system capable of dechlorinating sodium aluminate solution is characterized by comprising a reduction device, an electrolysis device connected with the output end of the reduction device, and a gas treatment device connected with the gas discharge end connected with the electrolysis device;

2. The system for dechlorinating a sodium aluminate solution according to claim 1, wherein the electrolysis apparatus further comprises a first circulation pump for circulating the anolyte within the anodic compartment.

3. The system for dechlorinating sodium aluminate solution according to claim 2, wherein the electrolysis device further comprises an electrolysis foreliquor high-level storage tank arranged between the reduction device and the tank body.

4. The system for dechlorinating sodium aluminate solution according to claim 3, wherein an anolyte storage tank is arranged between the first circulating pump and the tank body; the output end of the anolyte storage tank is provided with a valve for controlling the communication with the input end of the high-level liquid storage tank or the second liquid inlet of the pre-electrolysis liquid; and the first liquid outlet of the anode area is connected with the input end of the anolyte storage tank.

5. The system for dechlorinating sodium aluminate solution according to claim 1, wherein the leaching mechanism comprises at least two leaching towers connected in sequence, a solution preparation tank connected with the input ends of the leaching towers and connected with each other through a pipeline, a solution preparation pump for pumping the solution into the leaching towers, a solution preparation valve for controlling the communication between the solution preparation tank and the leaching towers, at least one second circulating pump for connecting two adjacent leaching towers, and a sodium hypochlorite product storage tank connected with the output ends of the leaching towers; and the absorption liquid in the leaching tower is sodium hydroxide.

6. The system for dechlorinating sodium aluminate solution according to claim 1, wherein the gas purification mechanism comprises an exhaust fan connected to the leaching mechanism, and a lime pit disposed at the downstream side of the gas flow direction and connected to the exhaust fan through a pipe.

7. The system for dechlorinating sodium aluminate solution according to any one of claims 1 to 6, further comprising a filter press disposed between the reduction unit and the electrolysis unit;

8. A system for dechlorinating sodium aluminate solution according to any one of claims 1 to 6, wherein the exhaust hood is provided with an on-line hydrogen gas detection mechanism.

9. The system for dechlorinating sodium aluminate solution according to any one of claims 1 to 6, wherein the electrolysis means further comprises at least one of the following arrangements:

10. The system for dechlorinating sodium aluminate solution according to any one of claims 1 to 6, further comprising a PLC controller for controlling the automatic operation of the whole system.