Device for producing sodium bromide by electrooxidation method

Abstract

The utility model discloses a device for producing sodium bromide by an electrooxidation method, which relates to the technical field of sodium bromide and comprises a bromine-containing brine tank, electrooxidation equipment, a brine tank, a blow-off tower, a waste brine tank, a first absorption tower, a second absorption tower, a demisting tower, an evaporation kettle, a centrifugal machine, a sodium hydroxide solution tank, a urea solution tank, a mother liquor tank and a disc dryer, the first absorption tower and the second absorption tower are respectively communicated with a sodium hydroxide solution tank and a urea solution tank, the electrooxidation equipment comprises an anode chamber and a cathode chamber, the anode chamber is communicated with a bromine-containing brine tank, and the anode chamber is communicated with a brine tank; bromine-containing brine is directly electrolyzed through electrooxidation equipment and then enters a blow-off tower, bromine-containing gas sequentially enters a first absorption tower and a second absorption tower to be circularly absorbed for multiple times, and meanwhile, a sodium hydroxide solution is adopted as an oxidizing agent and a urea solution is adopted as a reducing agent in the first absorption tower and the second absorption tower; other components are not easily doped, and the extraction precision of sodium bromide is high.

Description

Technical Field

[0001] The utility model relates to the technical field of sodium bromide, in particular to a device for producing sodium bromide by an electro-oxidation method. Background Art

[0002] At present, chlorine is mostly used to oxidize bromine-containing brine in bromine extraction technology. After bromide ions are oxidized into bromine element by chlorine, they enter the blowing tower and air is used to blow out the bromine element in the bromine-containing brine, and then the air containing bromine element is discharged into the absorption tower. However, when chlorine is used to oxidize bromine-containing brine, chlorine is likely to remain, resulting in the final sodium bromide product being impure and containing excess chloride ions. It needs to be sprayed with bromine-containing brine or hydrogen bromide, but this method has certain limitations and requires the addition of a first-level spray tower, which increases the burden on the system. In addition, there are relatively large risks in the storage and transportation of chlorine.

[0003] After searching, the publication number is CN216237303U, which discloses a device for extracting sodium bromide from brine. The anode chamber of the ion membrane electrolyzer is connected to the blow-out tower through the anode liquid overflow pipeline, the cathode chamber is connected to the absorption tower through the cathode liquid overflow pipeline, and the top gas phase outlet of the blow-out tower is connected to the bottom gas phase inlet of the absorption tower through a pipeline; the absorption tower is connected to the absorption liquid feed port of the cathode chamber through a pipeline. The whole process does not require the use of chlorine to oxidize bromide ions, and only requires the consumption of electric energy, a small amount of iron powder and sodium hydroxide. The operation is safe, the steps are simple, and the cost is low. At the same time, the iron ions in the cathode chamber are reduced to ferrous ions and can overflow with the cathode liquid to the absorption tower to re-capture the bromine molecules. The raw materials can be recycled, which reduces the cost. However, ferrous bromide is added in the absorption tower, and hydrobromic acid is added in the filter residue tank to dissolve the iron ions and ferrous ions in the filter residue to generate ferric bromide and ferrous bromide. In the process of extracting sodium bromide, other components are easily mixed, and the extraction accuracy of sodium bromide is not ideal. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a device for producing sodium bromide by electro-oxidation method in view of the above shortcomings, which overcomes the defects of the prior art that other components are easily mixed and the extraction precision of sodium bromide is not ideal; and achieves the purpose of not being easily mixed with other components and having high extraction precision of sodium bromide.

[0005] In order to solve the above technical problems, the technical solution of the utility model is: a device for producing sodium bromide by electro-oxidation, characterized in that it includes a bromine-containing brine tank, electro-oxidation equipment, a brine tank, a blow-out tower, a waste brine pool, a first absorption tower, a second absorption tower, a demister tower, an evaporator, a centrifuge, a sodium hydroxide solution pool, a urea solution pool, a mother liquor tank and a disc dryer;

[0006] The first absorption tower and the second absorption tower are respectively connected to the sodium hydroxide solution pool and the urea solution pool;

[0007] The electro-oxidation equipment comprises an anode chamber and a cathode chamber, wherein the anode chamber is communicated with a bromine-containing brine tank, and the anode chamber is communicated with a brine tank.

[0008] Furthermore, a first spray layer is provided at the upper part of the blowing tower, the first spray layer is connected to the brine tank, a blowing tower port is provided at the top of the blowing tower, and the bottom of the blowing tower is connected to the waste brine pool.

[0009] Furthermore, the top of the first absorption tower is provided with an absorption tower port, the absorption tower port is connected with the blowing tower port, the bottom of the first absorption tower is provided with a liquid level gauge, the upper part of the first absorption tower is provided with a second spray layer, the bottom of the first absorption tower is connected with the evaporation kettle, and the bottom of the first absorption tower is connected with the second spray layer;

[0010] The structure of the second absorption tower is the same as that of the first absorption tower.

[0011] Furthermore, a first pressure gauge and a brine pump are provided between the first spray layer and the brine tank.

[0012] Furthermore, a second pressure gauge, a pH meter and an absorption pump are provided between the bottom of the first absorption tower and the second spray layer.

[0013] Furthermore, the first absorption tower is connected to the second absorption tower, the second absorption tower is connected to the demisting tower, and a circulating fan is provided between the demisting tower and the blowing tower.

[0014] Furthermore, the evaporating kettle is connected to a centrifuge, the mother liquor tank and the disc dryer are respectively connected to the centrifuge, and a mother liquor pump is provided between the evaporating kettle and the mother liquor tank.

[0015] Furthermore, the solution in the sodium hydroxide solution pool is a 30% sodium hydroxide solution, and the solution in the urea solution pool is a 40% urea solution.

[0016] The utility model adopts the above technical scheme, and has the following advantages compared with the prior art: bromine-containing brine enters the electro-oxidation equipment for electrolysis, and the voltage is controlled to 1.5ev. In the anode chamber, the bromide ions in the bromine-containing brine are oxidized into bromine molecules, and hydrogen is generated in the cathode chamber. After the electrolysis is completed, the electrolysis completion liquid enters the brine tank from the anode chamber, and the electrolysis completion liquid is sprayed into the blow-out tower through the first spray pipe under the action of the brine pump, and the bromine element in the electrolysis completion liquid is blown out by air, and the remaining electrolysis completion liquid falling into the bottom of the blow-out tower is discharged into the waste brine pool, and the blown bromine element is mixed with air to form bromine-containing gas, and the bromine-containing gas enters the first absorption tower through the pipeline, and at the same time, 30% sodium hydroxide solution and 40% urea solution are passed into the first absorption tower, and 30% sodium hydroxide solution and 40% urea solution are sprayed into the second absorption tower through the second spray pipe under the action of the absorption pump. In the first absorption tower, the bromine-containing gas reacts chemically with the 30% sodium hydroxide solution and the 40% urea solution to generate a sodium bromide solution which falls into the bottom of the first absorption tower, i.e., the liquid at the bottom of the first absorption tower is a mixture of the 30% sodium hydroxide solution, the 40% urea solution and the sodium bromide solution. The mixture is sprayed into the first absorption tower again through the second spray pipe under the action of the absorption pump. The 30% sodium hydroxide solution and the 40% urea solution in the mixture react chemically with the bromine-containing gas again to continuously generate a sodium bromide solution. The cycle is repeated for many times. When the pH meter displays 7.0, it proves that the 30% sodium hydroxide solution and the 40% urea solution are completely consumed, i.e., the solution at the bottom of the first absorption tower is only a sodium bromide solution. The first valve is closed, the second valve is opened, and the sodium bromide solution enters the evaporator to evaporate excess water to obtain a concentrated sodium bromide solution.

[0017] At the same time, 30% sodium hydroxide solution and 40% urea solution are introduced into the second absorption tower, and the bromine-containing gas introduced into the first absorption tower is transported to the second absorption tower through a pipeline. The 30% sodium hydroxide solution and 40% urea solution react chemically with the bromine-containing gas in the second absorption tower. The reaction process in the second absorption tower is the same as the reaction process in the first absorption tower, and will not be described in detail here. The generated sodium bromide solution is transported to an evaporator to evaporate excess water to obtain a concentrated sodium bromide solution.

[0018] The concentrated sodium bromide solution enters the centrifuge to remove excess water and discharge the water into the mother liquor tank. The sodium bromide product enters the disc dryer and is completely dehydrated by high-temperature steam to obtain dry sodium bromide solid.

[0019] The excess bromine-containing gas in the second absorption tower enters the demister tower through a pipeline to remove excess liquid. Under the action of the circulating fan, the bromine-containing gas is re-transported to the blow-out tower through a circulating pipeline for further recycling.

[0020] The bromine-containing brine is directly electrolyzed by the electro-oxidation equipment and then enters the blowing tower. The blown-out bromine element mixes with the air to form bromine-containing gas which enters the first absorption tower and the second absorption tower in turn for multiple cycles of absorption. At the same time, sodium hydroxide solution is used as the oxidant and urea solution as the reducing agent in the first absorption tower and the second absorption tower. In the process of extracting sodium bromide, it is not easy to be mixed with other components, and the extraction accuracy of sodium bromide is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The present invention is a schematic diagram of the structure of a device for producing sodium bromide by electro-oxidation method in an embodiment of the present invention.

[0022] In the figure: 1-electro-oxidation equipment, 2-brine tank, 3-brine pump, 4-blowing tower, 5-first absorption tower, 6-second absorption tower, 7-demist tower, 8-circulating fan, 9-bromine-containing brine tank, 10-first pressure gauge, 11-second pressure gauge, 12-liquid level gauge, 13-connecting pipeline, 14-absorption pump, 15-evaporation kettle, 16-centrifuge, 17-mother liquor pump, 18-mother liquor tank, 19-disc dryer, 20-feeding pipeline, 21-first spray pipeline, 22-waste brine pool, 23-second spray pipeline, 24-anode chamber, 25-first spray layer, 26-second spray layer, 27-cathode chamber, 28-pH meter, 29-first valve, 30-second valve, 31-urea solution pool, 32-circulating pipeline, 33-blowing tower mouth, 34-absorption tower mouth, 35-sodium hydroxide solution pool. DETAILED DESCRIPTION

[0023] The specific implementation methods of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these implementation methods is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each implementation method of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] Examples, such as Figure 1 As shown, a device for producing sodium bromide by electro-oxidation method includes a bromine-containing brine tank 9, an electro-oxidation device 1, a brine tank 2, a blowing tower 4, a waste brine pool 22, a first absorption tower 5, a second absorption tower 6, a demister tower 7, an evaporator 15, a centrifuge 16, a mother liquor tank 18 and a disc dryer 19.

[0025] The electro-oxidation device 1 includes an anode chamber 24 and a cathode chamber 27. The electro-oxidation device 1 is a prior art and will not be described in detail herein. A feed pipe 20 is provided between the anode chamber 24 and the bromine-containing brine tank 9. The anode chamber 24 is connected to the brine tank 2 through a pipe. A first spray layer 25 is provided on the upper part of the blow-out tower 4. A first spray pipe 21 is provided between the first spray layer 25 and the brine tank 2. A first pressure gauge 10 and two brine pumps 3 arranged in parallel are provided on the first spray pipe 21. The first pressure gauge 10 is used to detect the pressure of the first spray pipe 21, and it can be observed whether the brine pump 3 is faulty and whether the first spray layer 25 is blocked. A blow-out tower port 33 is provided at the top of the blow-out tower 4, and the bottom of the blow-out tower 4 is connected to the waste brine pool 22 through a pipe.

[0026] An absorption tower port 34 is provided at the top of the first absorption tower 5, and the absorption tower port 34 is connected to the blowing tower port 33 by a pipeline. A liquid level meter 12 is provided at the bottom of the first absorption tower 5 for measuring the position of the liquid in the first absorption tower 5. A second spray layer 26 is provided at the top of the first absorption tower 5. The bottom of the first absorption tower 5 is connected to a sodium hydroxide solution pool 35 and a urea solution pool 31. The bottom of the first absorption tower 5 is connected to an evaporator 15. A second spray pipeline 23 is provided between the bottom of the first absorption tower 5 and the second spray layer 26. A second pressure gauge 11, a pH meter 28 and two absorption pumps 14 arranged in parallel are provided on the second spray pipeline 23. The pH meter 28 is used to monitor whether the solution reaction has reached the end point. The second pressure gauge 11 is used to detect the pressure of the second spray pipeline 23, so as to observe whether the absorption pump 14 has a fault and whether the second spray layer 26 is blocked.

[0027] A connecting pipe 13 is provided between the first absorption tower 5 and the second absorption tower 6. The structure of the second absorption tower 6 is the same as that of the first absorption tower 5 and will not be described in detail herein. The second absorption tower 6 is connected to the defogger 7. A circulation pipe 32 is provided between the defogger 7 and the blowing tower 4. A circulation fan 8 is provided on the circulation pipe 32.

[0028] The evaporator 15 is connected to the centrifuge 16 , the mother liquor tank 18 and the disc dryer 19 are respectively connected to the centrifuge 16 via pipelines, and a mother liquor pump 17 is provided between the evaporator 15 and the mother liquor tank 18 .

[0029] The solution in the sodium hydroxide solution tank 35 is a 30% sodium hydroxide solution, and the solution in the urea solution tank 31 is a 40% urea solution.

[0030] Usage method: bromine-containing brine enters the electro-oxidation equipment 1 for electrolysis, and the voltage is controlled to 1.5ev. In the anode chamber 24, the bromide ions in the bromine-containing brine are oxidized into bromine molecules, and hydrogen is generated in the cathode chamber 27. After the electrolysis is completed, the electrolysis completed liquid enters the brine tank 2 from the anode chamber 24. The electrolysis completed liquid is sprayed into the blow-out tower 4 through the first spray pipe 21 under the action of the brine pump 3. The bromine element in the electrolysis completed liquid is blown out by air, and the remaining electrolysis completed liquid falling into the bottom of the blow-out tower 4 is discharged into the waste brine pool 22. The blown bromine element is mixed with air to form bromine-containing gas. The bromine-containing gas enters the first absorption tower 5 through the pipeline. At the same time, 30% sodium hydroxide solution and 40% urea solution are passed into the first absorption tower 5. 30% sodium hydroxide solution and 40% urea solution are sprayed into the first absorption tower 5 through the second spray pipe 23 under the action of the absorption pump 14. The liquid at the bottom of the first absorption tower 5 is a mixture of 30% sodium hydroxide solution, 40% urea solution and sodium bromide solution. The mixture is sprayed into the first absorption tower 5 again through the second spray pipe 23 under the action of the absorption pump 14. The 30% sodium hydroxide solution and 40% urea solution in the mixture react chemically with the bromine-containing gas again to continue to generate sodium bromide solution. The cycle is repeated many times. When the pH meter 28 shows 7.0, it proves that the 30% sodium hydroxide solution and 40% urea solution are completely consumed, that is, the solution at the bottom of the first absorption tower 5 is only sodium bromide solution. The first valve 29 is closed, and the second valve 30 is opened. The sodium bromide solution enters the evaporator 15 to evaporate excess water to obtain a concentrated sodium bromide solution.

[0031] At the same time, 30% sodium hydroxide solution and 40% urea solution are introduced into the second absorption tower 6, and the bromine-containing gas introduced into the first absorption tower 5 is transported to the second absorption tower 6 through a pipeline. The 30% sodium hydroxide solution and the 40% urea solution react chemically with the bromine-containing gas in the second absorption tower 6. The reaction process in the second absorption tower 6 is the same as the reaction process in the first absorption tower 5, and will not be described in detail here. The generated sodium bromide solution is transported to the evaporator 15 to evaporate excess water to obtain a concentrated sodium bromide solution.

[0032] The sodium bromide concentrated solution enters the centrifuge 16 to remove excess water and discharge the water into the mother liquor tank 18. The sodium bromide product enters the disc dryer 19 to completely remove water through high-temperature steam to obtain dry sodium bromide solid.

[0033] The excess bromine-containing gas in the second absorption tower 6 enters the demister tower 7 through a pipeline to remove excess liquid. Under the action of the circulating fan 8, the bromine-containing gas is transported back to the blowing tower 4 through the circulating pipeline 32 for recycling again.

[0034] The bromine-containing brine is directly electrolyzed by the electro-oxidation device 1 and then enters the blowing tower 4. The blown-out bromine element is mixed with air to form a bromine-containing gas which enters the first absorption tower 5 and the second absorption tower 6 in turn for multiple cycles of absorption. At the same time, the first absorption tower 5 and the second absorption tower 6 both use sodium hydroxide solution as an oxidant and urea solution as a reducing agent. In the process of extracting sodium bromide, it is not easy to be mixed with other components, and the extraction accuracy of sodium bromide is high.

[0035] The above is a detailed description of the embodiments of the present invention in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

Claims

1. A device for producing sodium bromide by electro-oxidation, characterized in that: It comprises a bromine-containing brine tank (9), an electro-oxidation device (1), a brine tank (2), a blow-out tower (4), a waste brine pool (22), a first absorption tower (5), a second absorption tower (6), a demister (7), an evaporator (15), a centrifuge (16), a sodium hydroxide solution pool (35), a urea solution pool (31), a mother liquor tank (18) and a disc dryer (19); The first absorption tower (5) and the second absorption tower (6) are respectively connected to the sodium hydroxide solution pool (35) and the urea solution pool (31); The electro-oxidation device (1) comprises an anode chamber (24) and a cathode chamber (27), wherein the anode chamber (24) is connected to a bromine-containing brine tank (9), and the anode chamber (24) is connected to a brine tank (2).

2. The device for producing sodium bromide by electro-oxidation as claimed in claim 1, characterized in that: The blowing tower (4) is provided with a first spray layer (25) at the top, the first spray layer (25) is connected to the brine tank (2), a blowing tower port (33) is provided at the top of the blowing tower (4), and the bottom of the blowing tower (4) is connected to the waste brine pool (22).

3. A device for producing sodium bromide by electro-oxidation as claimed in claim 2, characterized in that: The top of the first absorption tower (5) is provided with an absorption tower port (34), the absorption tower port (34) is connected to the blowing tower port (33), the bottom of the first absorption tower (5) is provided with a liquid level meter (12), the upper part of the first absorption tower (5) is provided with a second spray layer (26), the bottom of the first absorption tower (5) is connected to the evaporation kettle (15), and the bottom of the first absorption tower (5) is connected to the second spray layer (26); The structure of the second absorption tower (6) is the same as that of the first absorption tower (5).

4. A device for producing sodium bromide by electro-oxidation as claimed in claim 2, characterized in that: A first pressure gauge (10) and a brine pump (3) are provided between the first spray layer (25) and the brine tank (2).

5. The device for producing sodium bromide by electro-oxidation as claimed in claim 3, characterized in that: A second pressure gauge (11), a pH meter (28) and an absorption pump (14) are provided between the bottom of the first absorption tower (5) and the second spray layer (26).

6. The device for producing sodium bromide by electro-oxidation as claimed in claim 1, characterized in that: The first absorption tower (5) is connected to the second absorption tower (6), the second absorption tower (6) is connected to the demister tower (7), and a circulating fan (8) is provided between the demister tower (7) and the blowing tower (4).

7. The device for producing sodium bromide by electro-oxidation as claimed in claim 1, characterized in that: The evaporating kettle (15) is connected to the centrifuge (16), the mother liquor tank (18) and the disc dryer (19) are respectively connected to the centrifuge (16), and a mother liquor pump (17) is provided between the evaporating kettle (15) and the mother liquor tank (18).

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