A device for continuously producing calcium chloride solution by using carbide slag and hydrogen chloride

Abstract

The utility model discloses a device for continuously producing calcium chloride by utilizing carbide slag and hydrogen chloride, which comprises a neutralization reactor, a circulating pump, a membrane separator and a circulating cooler. The neutralization reactor is provided with a circulating pipeline. Reaction liquid is connected to the inlet of the membrane separator by the circulating pipeline and the circulating pump. The turbid liquid outlet of the membrane separator is connected to the inlet of the circulating cooler. The outlet of the circulating cooler is connected to the neutralization reactor by the circulating pipeline. The turbid liquid is collected at the outlet of the circulating cooler. The clear liquid of the membrane separator is collected in a calcium liquid pool. The device can continuously add hydrogen chloride and carbide slag raw materials and continuously collect calcium chloride solution by controlling the inlet and outlet material three valve groups. The large circulating flux and the circulating cooler can remove a large amount of neutralization reaction heat, increase the hourly feed amount and improve the production capacity of the device.

Description

Technical Field

[0001] This utility model relates to a method for continuous reaction production of calcium chloride solution, specifically to an apparatus for continuous production of calcium chloride solution using carbide slag and hydrogen chloride, belonging to the field of chemical production technology. Background Technology

[0002] With the development of industries such as fluorochemicals, epichlorohydrin, chlor-alkali, compound fertilizers, and polysilicon, a large amount of by-product hydrogen chloride is generated during production. After absorption, hydrochloric acid is produced, which not only wastes a lot of water resources, but also results in waste hydrochloric acid that cannot be used or discharged.

[0003] Carbide slag is the residue after the hydrolysis of carbide. It is a highly alkaline solid waste, and its main component is Ca(OH)2. A large amount of carbide slag in China cannot be utilized as a resource. Long-term stockpiling has occupied a large amount of land resources and polluted the surrounding land and water bodies.

[0004] One of the main methods for producing calcium chloride solution is through the reaction of hydrochloric acid and limestone. After processing, calcium chloride solution, anhydrous calcium chloride, and calcium chloride dihydrate can be obtained. Calcium chloride has extremely strong hygroscopic properties and is widely used in de-icing agents, desiccants, oilfield cementing agents, and early-strength building agents.

[0005] Domestic equipment for producing calcium chloride using hydrochloric acid and limestone has a slow reaction rate, low production load, long reaction time, small production capacity, large equipment investment, and releases a large amount of carbon dioxide, increasing carbon emissions. Utility Model Content

[0006] To address the resource utilization of calcium carbide slag and hydrogen chloride, this invention provides a device for the continuous production of calcium chloride solution using calcium carbide slag and hydrogen chloride.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0008] An apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride, comprising a neutralization reactor, a circulating pump, a membrane separator, and a circulating cooler connected in sequence; the neutralization reactor is equipped with a circulating pipeline, the reaction liquid is connected to the inlet of the membrane separator via the circulating pump through the circulating pipeline, the turbid liquid outlet of the membrane separator is connected to the inlet of the circulating cooler, and the outlet of the circulating cooler is connected to the neutralization reactor through the circulating pipeline; the clear liquid from the membrane separator is collected into a calcium solution pool.

[0009] Preferably, the neutralization reactor is equipped with a stirrer, a guide tube, and a wire mesh demister; the neutralization reactor is provided with a hydrogen chloride inlet and a calcium carbide slag slurry inlet, which extend into the guide tube through nozzles.

[0010] Preferably, a wire mesh demister is provided at the top of the neutralization reactor; a rinsing water pipe is provided on the wire mesh demister.

[0011] Preferably, the apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride further includes a hydrogen chloride inlet flow meter and a hydrogen chloride inlet three-valve assembly. One end of the hydrogen chloride inlet flow meter is connected to the hydrogen chloride inlet, and the other end of the hydrogen chloride inlet flow meter is connected to the hydrogen chloride inlet three-valve assembly.

[0012] Preferably, the apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride further includes a carbide slag inlet flow meter and a carbide slag inlet three-valve group, one end of the carbide slag inlet flow meter being connected to the carbide slag inlet, and the other end of the carbide slag inlet flow meter being connected to the carbide slag inlet three-valve group.

[0013] Preferably, the apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride further includes a reaction solution pH meter, one end of which is connected to the inlet pipeline of the circulating pump, and the other end of which is connected to the outlet pipeline of the circulating pump.

[0014] Preferably, the reactor body comprises an upper cone, an intermediate cylinder, and a lower cone from top to bottom; its interior includes a flow guide tube, a stirrer, and a wire mesh demister.

[0015] The lower cone is an inverted cone structure with a stirrer at its center. A reaction liquid circulation pipe outlet is provided next to the stirrer, and a reaction liquid circulation pipe inlet is provided next to the stirrer. The reaction liquid circulation pipe inlet is connected to a circulation pump.

[0016] The intermediate cylinder is equipped with a hydrogen chloride gas inlet and a carbide slag slurry inlet, and extends into the interior of the guide cylinder through a long nozzle; the intermediate cylinder is also equipped with a circulation pipeline outlet for the reaction liquid.

[0017] The center of the upper cone is the outlet for the reaction exhaust gas, and a wire mesh demister is installed before the exhaust gas is discharged; a flushing water pipe is provided above the wire mesh demister.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] Hydrogen chloride gas can react directly with calcium carbide slag slurry without the need for water absorption to form hydrochloric acid, thus saving water resources by eliminating the large amount of water used in the hydrochloric acid absorption process.

[0020] The reaction is continuous and the production capacity is large. The continuous addition of hydrogen chloride and calcium carbide slag raw materials and the continuous extraction of calcium chloride solution can be achieved through the control of the three valve groups for feeding and discharging. In addition, the large circulation throughput and circulating cooler can remove a large amount of heat of neutralization reaction, increase the hourly feed rate, and improve the production capacity of the unit.

[0021] Impurities in the reaction solution are removed by a membrane separator to obtain the finished calcium chloride solution. Impurity separation can be completed without the use of a filter press, avoiding the complicated operation and harsh working environment of filter press unloading, and saving a lot of manpower.

[0022] Compared with the traditional acid process for producing calcium chloride, this method eliminates the need to add lime slurry to adjust the pH of the calcium chloride solution from acidic to alkaline. The pH is directly controlled to be weakly alkaline during the reaction process, preventing the acidic gases hydrogen chloride and hydrogen sulfide from escaping with the tail gas and controlling the odor problem of the reaction tail gas in the calcium chloride production process from carbide slag. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the apparatus for the continuous production of calcium chloride solution using carbide slag and hydrogen chloride according to this utility model.

[0024] Figure 2 This is a schematic diagram of the neutralization reactor of this utility model.

[0025] The components include: 1. Calcium carbide slag inlet flow meter; 2. Calcium carbide slag inlet three-valve assembly; 3. Hydrogen chloride inlet gas flow meter; 4. Hydrogen chloride inlet gas three-valve assembly; 5. Neutralization reactor; 6. Circulation pump; 7. Membrane separator; 8. Circulation cooler; 9. Calcium solution tank; 10. Reaction liquid pH meter; 11. Turbid liquid outlet flow meter; 12. Turbid liquid outlet three-valve assembly; 13. Clear liquid outlet flow meter; 14. Clear liquid outlet three-valve assembly; 15. Calcium carbide slag slurry inlet; 16. Hydrogen chloride gas inlet; 17. Circulation pipeline inlet; 18. Agitator; 19. Flow guide tube; 20. Circulation pipeline outlet; 21. Wire mesh demister; 22. Flushing water pipe; 23. Reaction tail gas outlet. Detailed Implementation

[0026] To make the technical solution, purpose, and advantages of this utility model clearer, the present utility model will be further described below in conjunction with specific embodiments.

[0027] like Figure 1 As shown, some embodiments of this utility model provide an apparatus for the continuous production of calcium chloride solution using carbide slag and hydrogen chloride. The apparatus includes a neutralization reactor 5, a circulating pump 6, a membrane separator 7, and a circulating cooler 8. The neutralization reactor 5 is equipped with a circulating pipeline. The reaction liquid is connected to the inlet of the membrane separator 7 via the circulating pipeline inlet 17 by the circulating pump 6. The turbid liquid outlet of the membrane separator 7 is connected to the inlet of the circulating cooler 8. The outlet of the circulating cooler 8 is connected to the neutralization reactor 5 via the circulating pipeline outlet 20. The clear liquid from the membrane separator 7 is collected and sent to a calcium solution pool. The carbide slag and hydrogen chloride react in the neutralization reactor. The circulating pump ensures uniform mixing of the materials. The membrane separator separates the reaction calcium solution from the reaction residue, and the circulating cooler removes the heat of reaction.

[0028] The lower part of the neutralization reactor 5 is provided with a hydrogen chloride inlet 16 and a calcium carbide slag slurry inlet 15, which are respectively connected to a hydrogen chloride inlet pipeline and a calcium carbide slag slurry inlet pipeline. A hydrogen chloride flow meter 1 and a hydrogen chloride inlet three-valve assembly 2 are provided on the hydrogen chloride inlet pipeline to monitor and control the hydrogen chloride inlet flow rate; a calcium carbide slag inlet flow meter 3 and a calcium carbide slag inlet three-valve assembly 4 are provided on the calcium carbide slag slurry inlet pipeline to monitor the calcium carbide slag slurry feed rate.

[0029] The neutralization reactor 5 has a circulation pipeline inlet 17 at its lower part, which is connected to the inlet of the circulation pump 6. The outlet of the circulation pump 6 is connected to the circulation pump discharge pipeline, which is connected to the membrane separator 7. The clear liquid separated by the membrane separator 7 is connected to the clear liquid collection pipeline, which is equipped with a clear liquid discharge flow meter 13 and a clear liquid discharge three-valve group 14 to monitor and control the clear liquid collection rate. The turbid liquid is connected to the turbid liquid pipeline through the outlet of the membrane separator 7, which is connected to the inlet of the circulating cooler 8. The circulating cooler 8 uses cooling water for heat exchange, and the outlet of the circulating cooler 8 is connected to the circulation pipeline of the neutralization reactor 5. Part of the turbid liquid is discharged after the turbid liquid collection rate is monitored and controlled by the turbid liquid collection flow meter 11 and the turbid liquid collection three-valve group 12.

[0030] like Figure 2 As shown, the neutralization reactor 5 includes a reactor body, which from top to bottom comprises an upper cone, a middle cylinder, and a lower cone. Inside, there is a stirrer 18, a guide tube 19, and a wire mesh demister 21. The guide tube 19 is fixed at the center of the neutralization crystallizer 5. The neutralization reactor 5 has a hydrogen chloride inlet 16 and a calcium carbide slag slurry inlet 15, respectively. A long nozzle extends from the outer wall of the neutralization crystallizer 19 into the guide tube 19, allowing the hydrogen chloride and calcium carbide slag to react inside the guide tube. The stirrer 18 is located at the bottom of the neutralization reactor 5, at the very center of the guide tube 19, ensuring uniform and thorough mixing of the reactants. The stirrer 18 pushes the reaction liquid to the top of the guide tube 19 and returns it to the bottom of the neutralization reactor 5 from the outside of the guide tube 19. The reaction exhaust gas is discharged from the top reaction exhaust gas outlet 23, passing through the wire mesh demister 21 before discharge to intercept entrained water droplets and reaction calcium liquid.

[0031] The lower cone is an inverted cone structure with a stirrer 18 at its center to ensure that hydrogen chloride and calcium carbide slag slurry are evenly dispersed and react completely. Next to the stirrer 18, a reaction liquid circulation pipe inlet 17 is provided, which is connected to a circulation pump 6 for the extraction and circulation of the reaction calcium solution in the reactor 5.

[0032] The intermediate cylinder is provided with a hydrogen chloride inlet 16 and a calcium carbide slag slurry inlet 15, which extend into the guide cylinder 19 through a long nozzle for continuous introduction of hydrogen chloride and calcium carbide slag slurry; the intermediate cylinder is provided with a reaction liquid circulation pipeline outlet 20 for completing the circulation of the reaction calcium liquid.

[0033] The center of the upper cone is the reaction tail gas outlet 23, which is connected to the corresponding tail gas treatment process. It is used to discharge the tail gas generated during the reaction and maintain the internal pressure of the neutralization reactor 5 between -10 kPa and -20 kPa to prevent the tail gas from escaping and affecting the surrounding environment of the device. A wire mesh demister 21 is installed before the tail gas is discharged to intercept impurities carried by the mist droplets in the reaction tail gas. A flushing water pipe 22 is provided above the wire mesh demister 21 to flush the impurity particles such as calcium chloride and carbide slag intercepted by the wire mesh and prevent the wire mesh demister from scaling.

[0034] The upper part of the neutralization reactor 5 is equipped with a wire mesh demister 21 to reduce the entrainment of mist in the reaction tail gas; a flushing water pipe 22 is provided above the wire mesh demister 21 to flush the demister regularly and prevent scale buildup on the demister mesh.

[0035] The reacting calcium solution in the neutralization reactor 5 is drawn out by the circulation pump 6 through the circulation pipe inlet 17 and enters the membrane separator 7, which is used to separate the unreacted impurities in the reacting calcium solution. After membrane filtration, the clear liquid is collected as the product and enters the calcium solution pool. The turbid liquid containing impurities enters the circulating cooler 8, where the heat of neutralization reaction is removed by cooling water. After being cooled by cooling water, the impurities are further precipitated. The precipitated impurities are discharged after the circulating cooler 8, and the remaining turbid liquid returns to the neutralization reactor 5 through the circulation pipeline for circulation.

[0036] The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride also includes a hydrogen chloride inlet flow meter 3 and a hydrogen chloride inlet three-valve group 4. One end of the hydrogen chloride inlet flow meter 3 is connected to the hydrogen chloride inlet, and the other end of the hydrogen chloride inlet flow meter 3 is connected to the hydrogen chloride inlet three-valve group 4; used to monitor and control the feed flow rate of hydrogen chloride in the neutralization reactor 5.

[0037] The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride also includes a carbide slag inlet flow meter 1 and a carbide slag inlet three-valve group 2. One end of the carbide slag inlet flow meter 1 is connected to the carbide slag inlet, and the other end of the carbide slag inlet flow meter 1 is connected to the carbide slag inlet three-valve group 2; used to monitor and control the feed flow rate of the carbide slag slurry in the neutralization reactor 5.

[0038] The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride also includes a reaction solution pH meter 10. One end of the reaction solution pH meter 10 is connected to the inlet pipeline of the circulation pump 6, and the other end of the reaction solution pH meter 10 is connected to the outlet pipeline of the circulation pump 6. It is used to monitor the pH of the reaction solution in the neutralization reactor 5, monitor the reaction process, and determine whether the conditions for extraction are met.

[0039] Some embodiments of this utility model provide a method for the continuous production of calcium chloride solution using carbide slag and hydrogen chloride, including the following steps:

[0040] First, add water to the neutralization reactor 5 to establish a liquid level that covers the agitator 18, to prevent the agitator from running dry and being damaged when it is started. Start the agitator 18 and the circulation pump 6 to establish circulation, and slowly increase the agitator speed to 65 rpm. The agitator speed should be controlled between 60-120 rpm. Too low a speed can easily cause uneven reaction and local overheating, while too high a speed will cause the liquid surface in the neutralization reactor to churn violently, which may damage the wire mesh demister. Add cooling water to the circulating cooler 8.

[0041] Open the three-valve group 2 for calcium carbide slag slurry and the three-valve group 4 for hydrogen chloride, and continuously feed hydrogen chloride and calcium carbide slag slurry into the neutralization reactor 5. Control the feed ratio of hydrogen chloride and calcium carbide slag at 2:1.1 (wt) according to the calcium hydroxide content in the calcium carbide slag (calculated with the effective component calcium hydroxide content accounting for 90wt%), so that the pH of the reaction liquid in the neutralization reactor is controlled between 7 and 8, reducing the escape of acidic gases such as HCl. The final reaction yields a 35% calcium chloride solution. It is recommended to control the concentration of calcium chloride solution between 25% and 35%. As the concentration of calcium solution increases, the viscosity of calcium chloride solution increases, which will increase the separation difficulty of the membrane separator. If the concentration of calcium solution is controlled too low, it will increase the overall water consumption.

[0042] The 35wt% calcium chloride solution obtained in the neutralization reactor 5 is drawn out from the inlet of the circulation pipeline by the circulation pump 6. The calcium carbide slag contains metallic impurities such as Mg, Al, and Fe, which precipitate out in the form of metal hydroxides. Some insoluble and unreacted substances in the calcium carbide slag also exist in the reaction calcium solution as impurities. The reaction calcium solution is sent to the membrane separator 7, where the impurities in the reaction solution are separated to obtain a clear calcium solution. The clear calcium solution is sent to the calcium solution tank 9 by the clear liquid discharge flow meter 13 and the clear liquid discharge three-valve group 14 to control the output.

[0043] The turbid liquid containing impurities enters the circulating cooler 8, where cooling water removes the heat of neutralization reaction, and the impurities further precipitate after the temperature of the turbid liquid drops to 50°C. The turbid liquid is then removed by controlling the discharge rate through the turbid liquid discharge flow meter 11 and the turbid liquid discharge three-valve group 12, maintaining the liquid level of the neutralization reactor at 30%. The remaining cooled reaction liquid is returned to the neutralization reactor 5 for circulation, and the temperature of the neutralization reactor 5 is controlled between 50°C and 70°C.

[0044] Compared with other widely used calcium chloride production equipment, the application of this utility model has the following advantages:

[0045] Low cost and low investment. Hydrogen chloride does not need to be absorbed by water to produce hydrochloric acid before reaction, saving a lot of water resources; it realizes the resource utilization of carbide slag and reduces the cost of purchasing limestone; compared with traditional series reactors, this utility model only requires a single reactor to complete the reaction.

[0046] The reaction is continuous and the production capacity is large. It achieves continuous feeding of hydrogen chloride and calcium carbide slag slurry and continuous extraction of reaction calcium solution. Compared with traditional batch reaction, it eliminates the feeding and discharging time required for intermittent reaction. Compared with traditional series reactors of the same volume, the production capacity is increased by about 4 times.

[0047] The reaction proceeded smoothly, achieving automated system control. Flow meters and three-valve assemblies were installed at both the inlet and outlet to monitor the feed rate in real time. A pH meter was used to monitor the reaction process in real time and determine if the feed ratio was appropriate. A membrane separator was used to separate impurities in the calcium solution online, and periodic backwashing removed impurities from the membrane tubes. Compared to traditional filter presses, this system effectively separated impurities online, eliminating the need for sludge discharge after filtration.

[0048] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solution of the present utility model are still within the scope of protection of the present utility model.

Claims

1. An apparatus for the continuous production of calcium chloride solution using carbide slag and hydrogen chloride, characterized in that: The apparatus for producing calcium chloride solution using carbide slag includes a neutralization reactor, a circulating pump, a membrane separator, and a circulating cooler connected in sequence. The neutralization reactor is equipped with a circulating pipeline, through which the reaction liquid is connected to the inlet of the membrane separator via the circulating pump. The turbid liquid outlet of the membrane separator is connected to the inlet of the circulating cooler, and the outlet of the circulating cooler is connected to the neutralization reactor via a circulating pipeline. The clear liquid from the membrane separator is collected into the calcium solution pool.

2. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: The neutralization reactor is equipped with a stirrer, a flow guide tube, and a wire mesh demister. The neutralization reactor has a hydrogen chloride inlet and a calcium carbide slag slurry inlet, which extend into the flow guide tube through nozzles.

3. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: A wire mesh demister is installed at the top of the neutralization reactor; a rinsing water pipe is installed on the wire mesh demister.

4. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: The apparatus for producing calcium chloride solution using carbide slag also includes a hydrogen chloride inlet flow meter and a hydrogen chloride inlet three-valve assembly. One end of the hydrogen chloride inlet flow meter is connected to the hydrogen chloride inlet, and the other end of the hydrogen chloride inlet flow meter is connected to the hydrogen chloride inlet three-valve assembly.

5. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: The apparatus for producing calcium chloride solution using carbide slag further includes a carbide slag inlet flow meter and a carbide slag inlet three-valve assembly. One end of the carbide slag inlet flow meter is connected to the carbide slag inlet, and the other end of the carbide slag inlet flow meter is connected to the carbide slag inlet three-valve assembly.

6. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: The apparatus for producing calcium chloride solution using carbide slag also includes a reaction solution pH meter, one end of which is connected to the inlet pipeline of the circulating pump, and the other end of which is connected to the outlet pipeline of the circulating pump.

7. The apparatus for continuously producing calcium chloride solution using carbide slag and hydrogen chloride according to claim 1, characterized in that: The reactor body, from top to bottom, includes an upper cone, a middle cylinder, and a lower cone; its interior includes a flow guide tube, a stirrer, and a wire mesh demister. The lower cone is an inverted cone structure with a stirrer at its center. A reaction liquid circulation pipe inlet is opened next to the stirrer and is connected to a circulation pump. The intermediate cylinder is equipped with a hydrogen chloride gas inlet and a carbide slag slurry inlet, and extends into the interior of the guide cylinder through a long nozzle; the intermediate cylinder is also equipped with a circulation pipeline outlet for the reaction liquid. The center of the upper cone is the outlet for the reaction exhaust gas, and a wire mesh demister is installed before the exhaust gas is discharged; a flushing water pipe is provided above the wire mesh demister.

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