Device for removing carbonate

Abstract

The utility model provides a device for removing carbonate. The device is characterized in that the inlet end of a first mixer is connected with a crude brine inlet pipe and a high-purity hydrochloric acid inlet pipe; the inlet end of the decarbonization kettle is connected to the outlet end of the first mixer; the inlet end of the outlet pipe is connected with the liquid outlet end of the decarbonization kettle; the inlet end of the water-sealed tank is connected with the gas outlet end of the decarbonization kettle. According to the utility model, the decarburization kettle is arranged, so that hydrogen ions and carbonate ions in the decarburization kettle can generate carbon dioxide and a small amount of hydrogen chloride gas, the carbonate ions can be effectively removed, and the efficiency of the decarburization process is improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of a potassium hydroxide production process, in particular to the technical field of a device for removing carbonate ions. BACKGROUND

[0002] In the existing potassium base production potassium chloride brine refining process, because the crude salt contains chemical impurities such as calcium and magnesium, the caustic soda-pure soda method is used for crude brine refining. In order to ensure that the calcium and magnesium ions are completely removed in the brine refining process, a certain amount of excess alkali must be ensured in the brine, which is helpful for the precipitation of calcium carbonate and magnesium hydroxide. In the process of using the brine for ion membrane electrolysis to produce potassium hydroxide, the excess carbonate ions enter the anode chamber of the electrolytic cell under high temperature and acidic conditions to produce carbon dioxide, thereby reducing the purity of the produced chlorine gas. At the same time, the excess carbonate penetrates the carboxylic acid layer and the sulfonic acid layer of the ion membrane under the action of reverse osmosis to generate potassium carbonate in the cathode chamber of the electrolysis, thereby reducing the quality of the potassium hydroxide. CONTENT OF THE UTILITY MODEL

[0003] The technical problem to be solved by the application is how to remove the excess carbonate ions to avoid affecting the carboxylic acid layer and the sulfonic acid layer of the ion membrane in the subsequent ion membrane electrolysis process, so as to avoid reducing the quality of the potassium hydroxide.

[0004] Therefore, the application provides a device for removing carbonate ions, which comprises:

[0005] A first mixer, an inlet end of the first mixer is connected with a crude brine inlet pipe and a high-purity hydrochloric acid inlet pipe;

[0006] A decarburization kettle, an inlet end of the decarburization kettle is connected to an outlet end of the first mixer;

[0007] An outlet pipe, an inlet end of the outlet pipe is connected to a liquid outlet end of the decarburization kettle;

[0008] A water seal tank, an inlet end of the water seal tank is connected to a gas outlet end of the decarburization kettle.

[0009] Further, one side of the high-purity hydrochloric acid inlet pipe is provided with a flow control valve.

[0010] Further, the first mixer is a static mixer.

[0011] Further, a stirring paddle is arranged in the decarburization kettle, and the gas outlet end is arranged at the top of the decarburization kettle.

[0012] Further, one side of the water seal tank is provided with a water seal tank air balance pipe.

[0013] Further, a second mixer is connected to the gas outlet of the decarburization kettle, and a potassium hydroxide inlet pipe is connected to the other inlet of the second mixer.

[0014] Further, a flow control valve is arranged on one side of the potassium hydroxide inlet pipe.

[0015] Further, an absorption water supplement pipeline and an absorption water overflow pipeline are arranged on one side of the water seal tank.

[0016] Compared with the prior art, the beneficial results of the present application are as follows:

[0017] The hydrogen ions in the decarburization kettle can react with carbonate ions to generate carbon dioxide and a small amount of hydrogen chloride gas, so that the carbonate ions can be effectively removed, and the efficiency of the decarburization process is improved.

[0018] The second mixer is arranged to effectively mix the salt water after removing the carbonate ions and the potassium hydroxide, so as to neutralize the acidic substances in the salt water, and keep the salt water clean and the pH value stable. BRIEF DESCRIPTION OF DRAWINGS

[0019] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments, read in conjunction with the accompanying drawings:

[0020] Figure 1 is a schematic view of a device for removing carbonate according to the present application.

[0021] First mixer: 1

[0022] Coarse salt water inlet pipe: 11

[0023] High-purity hydrochloric acid inlet pipe: 12

[0024] Decarburization kettle: 2

[0025] Outlet pipe: 3

[0026] Water seal tank: 4

[0027] Water seal tank air balance pipe: 41

[0028] Second mixer: 5

[0029] Potassium hydroxide inlet pipe: 51

[0030] Flow control valve: 511

[0031] Absorption water supplement pipeline: 42

[0032] Absorption water overflow pipeline: 43 DETAILED DESCRIPTION

[0033] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the relevant utility model and not intended to limit the scope of the utility model. Furthermore, it should be noted that, for ease of description, only the parts relevant to the utility model are shown in the accompanying drawings.

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0035] like Figure 1 As shown, an apparatus for removing carbonate ions includes:

[0036] The first mixer 1 has its inlet end connected to the crude brine inlet pipe 11 and the high-purity hydrochloric acid inlet pipe 12.

[0037] Decarbonization vessel 2, the inlet end of which is connected to the outlet end of the first mixer 1;

[0038] Outlet pipe 3, the inlet end of which is connected to the liquid outlet end of decarbonization vessel 2;

[0039] Water seal tank 4, the inlet end of which is connected to the gas outlet end of decarbonization reactor 2.

[0040] This invention introduces crude brine into a first mixer 1 via a crude brine inlet pipe 11, while high-purity hydrochloric acid enters the first mixer 1 via a high-purity hydrochloric acid inlet pipe 12. Inside the first mixer 1, the crude brine and high-purity hydrochloric acid are thoroughly mixed to form acidified crude brine. Subsequently, this invention further mixes the brine through a decarbonation reactor 2, causing carbonate ions to react with hydrogen ions to generate carbon dioxide gas and water. Then, an outlet pipe 3 allows the decarbonized liquid to be discharged from the liquid outlet of the decarbonation reactor 2. Simultaneously, a water seal pipe 4 connects to the decarbonation reactor 2, allowing the carbon dioxide gas and a small amount of hydrogen chloride gas generated during the reaction in the decarbonation reactor 2 to be discharged from the gas outlet of the decarbonation reactor 2, and the gas to enter the water seal tank 4. Inside the water seal tank 4, the gas is absorbed by water, the carbon dioxide is released into the atmosphere, and the hydrogen chloride is absorbed by water, thus achieving the harmless treatment of the gas.

[0041] In a preferred embodiment, the crude brine in the crude brine inlet pipe 11 is a primary refined brine that has reached a temperature of 65°C after heat exchange with a steam heat exchanger and has an excess alkali content of 0.3-0.6 g / L.

[0042] In a preferred embodiment, the high-purity hydrochloric acid import pipe 12 is provided with a flow control valve 121 on one side; the flow control valve 121 can accurately control the flow of high-purity hydrochloric acid, which is crucial to maintaining the uniformity and efficiency of the reaction. In addition, by controlling the addition rate of hydrochloric acid, the reaction can be prevented from being too fast or too slow, thereby ensuring the stability of the reaction.

[0043] In a preferred embodiment, the first mixer 1 is a static mixer. The static mixer is usually composed of a series of mixing elements fixed in the pipeline, and does not require additional mechanical components, so the structure is simple and convenient to maintain; in addition, the static mixer can realize the full mixing of the fluid in a shorter pipeline length, improving the mixing efficiency.

[0044] In a preferred embodiment, the decarburization kettle 2 is provided with a stirring paddle 21, which can improve the mixing efficiency of the fluid in the decarburization kettle; in addition, the selection of the stirring paddle should consider the material characteristics, and the flat turbine stirring paddle is suitable for gas dispersion and suspended particle mixing, while the folding turbine stirring paddle is suitable for mixing under medium-high viscosity conditions. In addition, during stirring, the coarse salt water decarburization kettle maintains a positive pressure of 0.1MPA, and the stirring paddle 21 continuously stirs to form liquid backmixing, which is beneficial to gas reaction and escape.

[0045] In a preferred embodiment, the gas outlet end is arranged at the top of the decarburization kettle 2. This structure helps the gas to be discharged smoothly, reduces the residence time of the gas in the kettle, and improves the decarburization efficiency.

[0046] In a preferred embodiment, the water seal tank 4 is provided with a water seal tank air balance pipe 41 on one side. The main function of the water seal tank air balance pipe 41 is to balance the pressure inside and outside the water seal tank, to ensure that the water seal tank can operate stably under different operating conditions; the air balance pipe 41 allows the pressure inside the water seal tank 4 to exchange with the external atmospheric pressure, to maintain the stability of the tank pressure. This is crucial to prevent the tank body from being damaged due to excessive expansion or contraction.

[0047] In a preferred embodiment, the second mixer 5, one inlet end of the second mixer 5 is connected to the gas outlet end of the decarburization kettle 2, and the other inlet end of the second mixer 5 is connected to the potassium hydroxide import pipe 51.

[0048] In a preferred embodiment, a flow control valve 511 is provided on one side of the potassium hydroxide inlet pipe 51. Specifically, the concentration of potassium hydroxide in the inlet pipe 51 is 30%. After the second mixer 5 mixes the solution evenly, the pH value of the output brine is between 8.5 and 10.5, and it is finally sent to the resin tower for secondary brine purification. The flow control valve 511 can adjust the flow rate of potassium hydroxide as needed to ensure the uniformity and efficiency of the reaction. Specifically, potassium hydroxide, as a strong alkali, can neutralize acidic substances in the brine, such as carbon dioxide (CO2), preventing them from redissolving in the alkaline brine and forming calcium carbonate (CaCO3) precipitate with Ca2+, Mg2+, etc., thereby maintaining the cleanliness and pH stability of the brine. In addition, potassium hydroxide is used to further purify the brine, remove calcium and magnesium ions, and ultimately control the calcium and magnesium ion content to an extremely low level to meet the operating requirements of the electrolyzer.

[0049] In a preferred embodiment, the water seal tank 4 is provided with an absorption water supply pipe 42 and an absorption water overflow pipe 43 on one side. The absorption water supply pipe 42 is used to replenish water into the water seal tank to maintain an appropriate water level. The absorption water overflow pipe 43 is used to control the water level in the water seal tank 4 to prevent the water level from becoming too high. When the water level in the water seal tank 4 reaches a set height, excess water will be discharged through the absorption water overflow pipe 43 to keep the water volume in the water seal tank 4 within a safe and effective operating range.

[0050] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the utility model involved in this application is not limited to the technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described utility model concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. An apparatus for removing carbonate ions, characterized in that The application relates to a high-purity hydrochloric acid production device, which comprises the following: a first mixer, the inlet end of which is connected with a crude brine inlet pipe and a high-purity hydrochloric acid inlet pipe; a decarburization kettle, the inlet end of which is connected with the outlet end of the first mixer; an outlet pipe, the inlet end of which is connected with the liquid outlet end of the decarburization kettle; a water seal tank, the inlet end of which is connected with the gas outlet end of the decarburization kettle.

2. The device for removing carbonate ions according to claim 1, characterized in that: One side of the high-purity hydrochloric acid inlet pipe is provided with a flow control valve.

3. The device for removing carbonate ions according to claim 1, characterized in that: The first mixer is a static mixer.

4. The device for removing carbonate ions according to claim 1, characterized in that: The decarburization kettle is provided with stirring paddles, and the gas outlet end is arranged at the top of the decarburization kettle.

5. The device for removing carbonate ions according to claim 1, characterized in that: One side of the water seal tank is provided with a water seal tank air balance pipe.

6. The device for removing carbonate ions according to claim 1, characterized in that, The application further comprises: a second mixer, one inlet end of which is connected with the gas outlet end of the decarburization kettle, and the other inlet end of which is connected with a potassium hydroxide inlet pipe.

7. The device for removing carbonate ions according to claim 6, characterized in that: One side of the potassium hydroxide inlet pipe is provided with a flow control valve.

8. The device for removing carbonate ions according to claim 1, characterized in that: One side of the water seal tank is provided with an absorption water supplement pipeline and an absorption water overflow pipeline.

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