Gas-liquid reaction equipment, system thereof and method for preparing barium carbonate using the same

Abstract

The present invention belongs to the technical field of resource recycling, and relates to a gas-liquid reaction device, a system thereof, and a method for preparing barium carbonate using the same. The gas-liquid reaction device comprises: a first storage tank, a gradient pipeline, and a second storage tank; wherein the first storage tank comprises a liquid inlet and a gas outlet, the gradient pipeline comprises a gas inlet, and the second storage tank comprises a liquid outlet; the lower end of the first storage tank is connected to the upper end of the gradient pipeline, and the lower end of the gradient pipeline is connected to the second storage tank. The gas-liquid reaction device and its system of the present invention prepare barium carbonate, improve CO2 utilization and production efficiency, and the H2S / CO2 value in the exhaust gas is significantly improved, which can better meet the production requirements of downstream processes.

Description

Technical Field

[0001] The invention belongs to the technical field of resource recycling and relates to a gas-liquid reaction device, a system thereof and a method for preparing barium carbonate using the same. Background Art

[0002] Gas-liquid reaction equipment is a reactor used for gas-liquid reaction. Currently, commonly used gas-liquid reaction equipment includes plate towers and packed towers. However, the plate tower has a complex structure and the tower plates must be made of expensive materials. Packed towers are prone to scaling and are difficult to handle. Therefore, the workload and cost of operation and maintenance are very high.

[0003] Taking the industrial production of barium carbonate as an example, it is usually produced by a three-tower series intermittent operation method, in which the three towers are the main carbonization tower, the semi-carbonization tower, and the pre-carbonization tower. During the production process, the operator changes the route of carbon dioxide and tail gas through valves, thereby continuously switching the three towers to obtain barium carbonate products of different quality and particle size distribution. However, this process not only has large equipment and high investment costs, but also has the disadvantages of slow reaction, low efficiency, long process flow, difficult control, low CO2 utilization rate (60% to 70%), and high tail gas CO2 content that is difficult to meet the production requirements of downstream processes.

[0004] Therefore, there is an urgent need in the art for a gas-liquid reaction device with a small footprint, a short process flow and a low investment cost. Summary of the invention

[0005] The purpose of the present invention is to provide a gas-liquid reaction device, a system thereof and a method for preparing barium carbonate using the same in view of the defects of the prior art.

[0006] Specifically, the gas-liquid reaction equipment of the present invention includes: a first storage tank, a gradient pipeline, and a second storage tank; wherein the first storage tank includes a liquid inlet and a gas outlet, the gradient pipeline includes a gas inlet, and the second storage tank includes a liquid outlet; the lower end of the first storage tank is connected to the upper end of the gradient pipeline, and the lower end of the gradient pipeline is connected to the second storage tank.

[0007] Preferably, the gradient pipeline is composed of three or more pipelines with different diameters, wherein the diameter of the gradient pipeline decreases along the flow direction of the liquid.

[0008] Preferably, the gradient pipeline is composed of a first pipeline, a second pipeline and a third pipeline, the diameter of the first pipeline is larger than the diameter of the second pipeline, and the diameter of the second pipeline is larger than the diameter of the third pipeline.

[0009] Preferably, a first liquid distributor is provided between the first storage tank and the first pipeline, a second liquid distributor is provided between the first pipeline and the second pipeline, and the third pipeline is provided with a gas distributor, a monitor and a valve, wherein the monitor is located between the gas distributor and the valve.

[0010] The gas-liquid reaction system of the present invention comprises the above-mentioned gas-liquid reaction equipment, liquid supply equipment and gas supply equipment; wherein the liquid supply equipment is connected to the liquid inlet of the first storage tank through a pipeline, and the gas supply equipment is connected to the gas inlet of the gas distributor through a pipeline.

[0011] Preferably, the gas outlet of the first storage tank is connected to the equipment of the downstream process through a pipeline, and the pipeline is provided with a pressure gauge, a ratiometer and a valve; the pipeline between the gas supply equipment and the gas distributor is provided with a pressure gauge, a flow meter and a valve; the pipeline between the liquid supply equipment and the first storage tank is provided with a pump, a flow meter and a valve.

[0012] A method for preparing barium carbonate of the present invention adopts the above-mentioned gas-liquid reaction system, wherein the liquid supply device supplies yellow water to the first storage tank, and the gas supply device supplies carbon dioxide or kiln gas to the gas distributor.

[0013] Preferably, the concentration of barium sulfide in the yellow water is 100-150 g / L, and the content of carbon dioxide in the kiln gas is 30%-40%.

[0014] Preferably, the reaction temperature of the yellow water and the carbon dioxide is 70-80° C., and the pressure of the system during the reaction is 0.20-0.60 MPa.

[0015] Preferably, the yellow water is washed with hydrogen sulfide before being pumped into the first storage tank.

[0016] The technical solution of the present invention has the following beneficial effects:

[0017] (1) The gas-liquid reaction equipment of the present invention has a simple structure, is easy to control, and has low workload and cost for operation and maintenance;

[0018] (2) The gas-liquid reaction system of the present invention has a small footprint, a short process flow and low investment cost;

[0019] (3) The gas-liquid reaction equipment and system of the present invention are used to prepare barium carbonate, which improves the CO2 utilization rate and production efficiency, and the H2S / CO2 value in the exhaust gas is significantly improved, which can better meet the production requirements of the downstream process;

[0020] (4) The preparation method of barium carbonate of the present invention can obtain barium carbonate products with more concentrated particle size distribution and richer quality specifications, thereby continuously meeting market demand. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the following detailed description of the preferred embodiment.The drawings are only for the purpose of illustrating the preferred embodiments and are not to be construed as limiting the invention.

[0022] Figure 1 It is a schematic structural diagram of the gas-liquid reaction device and its system of the present invention;

[0023] Figure 2 It is a schematic diagram of the cross-sectional structure of the gas-liquid reaction equipment of the present invention. DETAILED DESCRIPTION

[0024] In order to fully understand the purpose, features and effects of the present invention, the present invention is described in detail through the following specific embodiments. Except for the following contents, the process method of the present invention adopts conventional methods or devices in the art. Unless otherwise specified, the following terms have the meanings commonly understood by those skilled in the art.

[0025] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] Specifically, according to the first aspect of the present invention, the present invention provides a gas-liquid reaction device, comprising a first storage tank 100, a gradient pipe 200, and a second storage tank 300; wherein, the first storage tank 100 comprises a liquid inlet and a gas outlet, the gradient pipe 200 comprises a gas inlet, and the second storage tank 300 comprises a liquid outlet; the lower end of the first storage tank 100 is connected to the upper end of the gradient pipe 200, and the lower end of the gradient pipe 200 is connected to the second storage tank 300.

[0028] The gas-liquid reactor of the present invention adopts a gradual change pipeline 200, which solves the problem of bulky reaction equipment and reduces investment cost.

[0029] Preferably, the gradual change pipeline 200 is composed of three or more pipelines with different diameters, wherein the diameter of the gradual change pipeline 200 gradually decreases along the flow direction of the liquid. With this structure, the gas and liquid can be fully contacted, thereby improving the reaction efficiency of the gas-liquid reactor.

[0030] More preferably, Figure 1 As shown, the gradient pipeline 200 is composed of a first pipeline 210 , a second pipeline 220 and a third pipeline 230 . The diameter of the first pipeline 210 is greater than that of the second pipeline 220 , and the diameter of the second pipeline 220 is greater than that of the third pipeline 230 .

[0031] Further preferably, Figure 1 , Figure 2 As shown, a first liquid distributor 211 is provided between the first storage tank 100 and the first pipeline 210, a second liquid distributor 212 is provided between the first pipeline 210 and the second pipeline 220, and the third pipeline 230 is provided with a gas distributor 231, a monitor 232 and a valve 233, wherein the monitor 232 is located between the gas distributor 231 and the valve 233.

[0032] The types of the first liquid distributor 211 and the second liquid distributor 212 can be tubular, double-layer row tube, trough, disc, impact, nozzle, pagoda, lotus, or combination, which are not specifically limited in the present invention. The first distributor 211 and the second distributor 212 can be provided to evenly distribute or redistribute the liquid, thereby increasing the effective surface of mass transfer and heat transfer, improving the contact between phases, and improving the efficiency of the gas-liquid reaction equipment.

[0033] Among them, the gas distributor 231 is a dynamic pipeline gas distributor. By arranging the gas distributor 231 in the gas-liquid reaction equipment, the introduced gas can be evenly distributed in the equipment, increasing the gas-liquid contact area, saving reaction time, and improving gas utilization.

[0034] The monitor 232 is an online tester for sulfide content or pH value, which is used to detect the properties of the system after the reaction, such as the content of barium sulfide or pH value. According to the results displayed by the detector, the reaction conditions can be adjusted accordingly.

[0035] The valve 233 is used to control the speed at which the system after the reaction enters the second storage tank.

[0036] Preferably, the first storage tank 100 further includes a liquid level gauge 110 and a pressure difference remote liquid level display 120 .

[0037] On the other hand, the present invention provides a gas-liquid reaction system, comprising the above-mentioned gas-liquid reaction equipment, liquid supply equipment and gas supply equipment; wherein the liquid supply equipment is connected to the liquid inlet of the first storage tank 100 through a pipeline, and the gas supply equipment is connected to the gas inlet of the gas distributor 231 through a pipeline.

[0038] Preferably, the gas outlet of the first storage tank 100 is connected to the thiourea or sulfur process equipment 700 through a pipeline, and the pipeline is provided with a pressure gauge 610, a ratiometer 630 and a valve 620; the pipeline between the gas supply equipment and the gas distributor / 231 is provided with a pressure gauge 530, a flowmeter 510 and valves 520, 540; the pipeline between the liquid supply equipment and the first storage tank room 100 is provided with a pump 410, a flowmeter 420 and a valve 430. By controlling the opening of the above valves, the pressure of the gas-liquid reaction system and the liquid level of the first storage tank 100 can fluctuate within a certain range to ensure the stable progress of the gas-liquid reaction. The reaction degree of the gas-liquid reaction can be determined by the monitor 232 and the ratiometer 630.

[0039] Among them, the relevant specifications and dimensions of the gas-liquid reaction equipment and its system of the present invention, such as the capacity of the first storage tank 100, the length of the gradient pipeline 200, the diameter of the gradient pipeline 200 and the relevant parameters of the auxiliary devices (such as: flow meter (420, 510), pressure gauge (530, 610), valve (620, 540, 430, 233), etc.), can be adjusted accordingly according to the actual output of the factory, and the present invention is not specifically limited here.

[0040] The following takes the preparation of barium carbonate by carbon dioxide and barium sulfide solution as an example to introduce in detail the operation, technical parameters, principle, etc. of the gas-liquid reaction device and the gas-liquid reaction system of the present invention. However, the application of the gas-liquid reaction device and the gas-liquid reaction system of the present invention is not limited to this, and it can also be used in the fields of removing carbon dioxide and acidic gases such as hydrogen sulfide from semi-water gas with alkaline liquid, and oxidizing ethylene in acetic acid solution of PdCl2-Cu2Cl2 to produce acetaldehyde.

[0041] Specifically, the present invention provides a method for preparing barium carbonate, using the above-mentioned gas-liquid reaction system, the liquid supply device supplies yellow water to the first storage tank 100, and the gas supply device supplies carbon dioxide or kiln gas to the gas distributor 231.

[0042] When kiln gas is supplied, a compressor (not shown) may be added to the pipeline so that the kiln gas enters the gas-liquid reaction device at a stable pressure.

[0043] Preferably, the concentration of barium sulfide in the yellow water is 100-150 g / L, and the content of carbon dioxide in the kiln gas is 30%-40%; the reaction molar ratio of barium sulfide to CO2 is 1:1, and accurate control of the ratio of yellow water to kiln gas or CO2 is achieved according to the concentration and content.

[0044] Preferably, the reaction temperature of the yellow water and the carbon dioxide is 70-80° C., and the pressure of the system during the reaction is 0.20-0.60 MPa.

[0045] The temperature of the yellow water when entering the barium carbonate production process from the previous process is above 80°C, thereby ensuring that the reaction temperature of the yellow water with the carbon dioxide when entering the gas-liquid reaction equipment is between 70-80°C.

[0046] By using a carbon dioxide distributor to continuously blow kiln gas or carbon dioxide into the gas-liquid reaction equipment, the gas-liquid contact area can be increased, the reaction time can be saved, and the CO2 utilization rate can be improved. Among them, the reaction time of carbon dioxide and barium sulfide is determined by the pipeline length, process control and endpoint analysis.

[0047] Preferably, the endpoint monitor 232 and the tail gas ratio meter 630 are used to determine whether the sulfur content in the barium slurry and the ratio of hydrogen sulfide to carbon dioxide meet the standards, and sampling is performed for experimental analysis to determine whether the particle size distribution, bulk density, activity, and fluidity of the barium carbonate product meet the technical requirements.

[0048] The present invention prepares barium carbonate by adopting the above-mentioned gas-liquid reaction equipment and system, thereby solving the problems of low CO2 utilization rate, H2S concentration failing to meet the production requirements of downstream processes, and unstable product quality in the traditional carbonization process.

[0049] Specifically, the process flow of the preparation method of barium carbonate of the present invention is as follows: a first storage tank 100 (in which yellow water is stored) is connected to a gradient pipeline 200 instead of a carbonization tower for carbonization reaction, a yellow water pump 410 and a compressor (not shown) continuously feed yellow water and raw gas according to a ratio, the yellow water reaches the gradient pipeline 200 through the first storage tank 100 and reacts with kiln gas or CO2 convection contact, the gas continues to react with the yellow water upward to generate H2S gas, multiple reaction steps are carried out simultaneously in the gradient pipeline 200, the hydrogen sulfide gas is separated into gas and liquid by a hydrogen sulfide separator and then fed into a thiourea or sulfur process, the barium carbonate slurry is transported to the second storage tank 300 through a pipeline, and then enters a dehydration process, and a barium carbonate product is obtained by gas-liquid separation. During the operation of the system, the balance and stability of the entire process system are maintained, continuous carbonization is achieved, and products that meet technical requirements and different quality specifications are produced through automatic interlocking control of key control points such as yellow water flow, kiln gas or CO2 flow and pressure, yellow water storage tank level, water-soluble sulfide content at the carbonization endpoint, tail gas pressure and H2S / CO2 value.

[0050] In the process of producing barium carbonate by carbonization, the barium carbonate particles and bulk density often change, and the reasons for the changes are difficult to find. Based on the traditional carbonization process, the inventors have conducted in-depth research on the reaction mechanism of barium sulfide solution and carbon dioxide, and creatively proposed to use hydrogen sulfide gas to wash the yellow water before it is pumped into the first storage tank 100. In this way, the barium hydrosulfide and barium hydroxide in the yellow water are converted into barium sulfide, the purity of the barium sulfide in the yellow water is improved, the particle size distribution of the obtained barium carbonate is more concentrated, and the quality specifications are more abundant, thereby continuously meeting market demand.

[0051] Practice has proved that the purity of barium carbonate prepared by the preparation method of barium carbonate of the present invention is above 99.5%, and the particle size (Malvern D50) distribution, carbon dioxide utilization rate, tail gas quality, etc. can all meet high standard requirements, the CO2 utilization rate (can reach more than 90%) is greatly improved, and the H2S / CO2 value in the tail gas is above 9.0, which can better meet the production requirements of downstream processes while ensuring product quality.

[0052] Example

[0053] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions. The raw materials used in the following examples are all conventionally purchased.

[0054] use Figure 1In the gas-liquid reaction system shown, the diameter of the first storage tank 100 is 0.8m, the diameter of the first pipe 210 in the gradient pipe is 325mm, the length is 12m, the diameter of the second pipe 220 is 108mm, the length is 5m, and the diameter of the third pipe 230 is 57mm, the length is 3m. The first liquid distributor 211 is a porous disc liquid distributor, the second liquid distributor 212 is a porous disc liquid distributor, and the gas distributor 231 is a dynamic pipeline gas distributor, the length is 3m.

[0055] Example 1

[0056] Check that all the equipment and instruments in the system are normal. The concentration of barium sulfide solution is 128g / L, and the CO2 concentration in the kiln gas is 32% and remains unchanged. Adjust the speed of the yellow water pump and the opening of the liquid inlet valve to keep the yellow water flow constant. At this time, the flow rate of the yellow water flow meter is 1.5m 3 / h, when the liquid level of the yellow water storage tank reaches 0.5-0.7m, control the opening of the discharge valve to stabilize the liquid level, and at the same time start the carbon dioxide compressor to send kiln gas, slowly open the tail gas vent valve, adjust the opening of the kiln gas inlet valve to control the inlet pressure to 0.144Mpa, and the flow rate is controlled at 83.52Nm 3 / h (the density of CO2 at room temperature is 1.9g / L). After the system is stable, the sulfur content in the barium carbonate product is monitored to be 0.17%, the liquid level in the yellow water storage tank is stable between 0.5 and 0.8m, the ratiometer shows that the tail gas H2S / CO2 value is 10.1, and the CO2 utilization rate is above 93%.

[0057] According to the thiourea process control indicators and product quality requirements, the end point is to control the water-soluble sulfide content in the barium carbonate slurry to ≤1g / L (in terms of BaS), the CO2 utilization rate must reach more than 90%, and the H2S / CO2 value in the tail gas must not be less than 9. Through experimental verification, all indicators have met the technical requirements.

[0058] Example 2

[0059] Check that all equipment and instruments in the system are normal. The concentration of barium sulfide solution is 135g / L, the CO2 concentration in the kiln gas is 30% unchanged, and the speed of the yellow water pump and the opening of the liquid inlet valve are adjusted to make the flow rate also stable at 1.5m 3 / h, when the liquid level of the yellow water storage tank reaches 0.5-0.7m, control the discharge valve opening to stabilize the liquid level, start the carbon dioxide compressor to send kiln gas, slowly open the tail gas vent valve, adjust the kiln gas inlet valve opening to control the inlet pressure to 0.15Mpa, and control the flow rate to 89.49Nm 3 / h (the density of CO2 at room temperature is 1.9g / L). After the system stabilizes, the sulfur content in the barium carbonate product is 0.15%, the liquid level in the yellow water storage tank is stable between 0.5 and 0.8m, the ratio meter shows that the tail gas H2S / CO2 value is 9.8, and the CO2 utilization rate is above 91%.

[0060] According to the thiourea process control indicators and product quality requirements, the end point is to control the water-soluble sulfide content in the barium carbonate slurry to ≤1g / L (in terms of BaS), the CO2 utilization rate must reach more than 90%, and the H2S / CO2 value in the tail gas must not be less than 9. Through experimental verification, all indicators have met the technical requirements.

[0061] Example 3

[0062] Check that all equipment and instruments in the system are normal. Analyze and detect that the concentration of barium sulfide solution is 128g / L and remains unchanged. Adjust the speed of the yellow water pump and the opening of the liquid inlet valve to maintain the yellow water flow rate at 1.5m 3 / h, when the liquid level in the yellow water storage tank reaches 0.5-0.7m, control the discharge valve opening to stabilize the liquid level, open the carbon dioxide control valve to feed carbon dioxide, open the tail gas vent valve slowly, and adjust the carbon dioxide intake valve opening to control the intake flow rate at 26.4Nm 3 / h (the density of CO2 at room temperature is 1.9g / L). After the system is stable, the sulfur content in the barium carbonate product is monitored to be 0.18%, the liquid level in the yellow water storage tank is stable between 0.5 and 0.8m, the ratiometer shows that the tail gas H2S / CO2 value is 9.56, and the CO2 utilization rate is over 91%.

[0063] According to the thiourea process control indicators and product quality requirements, the end point is to control the water-soluble sulfide content in the barium carbonate slurry to ≤1g / L (in terms of BaS), the CO2 utilization rate must reach more than 90%, and the H2S / CO2 value in the tail gas must not be less than 9. Through experimental verification, all indicators have met the technical requirements.

[0064] Example 4

[0065] Check that all equipment and instruments in the system are normal. Analyze and detect that the concentration of barium sulfide solution is 135g / L and remains unchanged. Adjust the speed of the yellow water pump and the opening of the liquid inlet valve to maintain the yellow water flow rate at 1.5m 3 / h, when the liquid level in the yellow water storage tank reaches 0.5-0.7m, control the discharge valve opening to stabilize the liquid level, open the carbon dioxide control valve to feed carbon dioxide, open the tail gas vent valve slowly, and adjust the carbon dioxide intake valve opening to control the intake flow rate at 27.748Nm 3 / h (the density of CO2 at room temperature is 1.9g / L). After the system is stable, the sulfur content in the barium carbonate product is monitored to be 0.14%, the liquid level in the yellow water storage tank is stable between 0.5 and 0.8m, the ratiometer shows that the tail gas H2S / CO2 value is 10.3, and the CO2 utilization rate is above 93%.

[0066] According to the thiourea process control indicators and product quality requirements, the end point is to control the water-soluble sulfide content in the barium carbonate slurry to ≤1g / L (in terms of BaS), the CO2 utilization rate must reach more than 90%, and the H2S / CO2 value in the tail gas must not be less than 9. Through experimental verification, all indicators have met the technical requirements.

[0067] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. The present disclosure is not limited to the precise structure described above and shown in the drawings, and various modifications and changes may be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims. If these modifications and variations fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A gas-liquid reaction device for preparing barium carbonate, characterized in that: include: A first storage tank, a gradient pipeline, and a second storage tank; wherein the first storage tank includes a liquid inlet and an air outlet, the gradient pipeline includes an air inlet, and the second storage tank includes a liquid outlet; the lower end of the first storage tank is connected to the upper end of the gradient pipeline, and the lower end of the gradient pipeline is connected to the second storage tank; The gradient pipeline is composed of a first pipeline, a second pipeline and a third pipeline, wherein the diameter of the first pipeline is larger than the diameter of the second pipeline, and the diameter of the second pipeline is larger than the diameter of the third pipeline; a first liquid distributor is provided between the first storage tank and the first pipeline, and a gas distributor is provided on the third pipeline; Wherein, the first storage tank is connected to the liquid supply device through the liquid inlet, and a pump is provided on the pipeline between the liquid supply device and the first storage tank; the gas distributor is connected to the gas supply device through the gas inlet; Among them, the liquid supply equipment supplies yellow water to the first storage tank, and the gas supply equipment supplies carbon dioxide or kiln gas to the gas distributor; the concentration of barium sulfide in the yellow water is 100-150g / L, and the content of carbon dioxide in the kiln gas is 30%-40%; the reaction temperature of the yellow water and the carbon dioxide is 70-80°C, and the pressure of the system during the reaction is 0.20-0.60MPa.

2. The device according to claim 1, characterized in that A second liquid distributor is provided between the first pipeline and the second pipeline, and a monitor and a valve are provided on the third pipeline, wherein the monitor is located between the gas distributor and the valve.

3. A gas-liquid reaction system, characterized in that: It comprises the gas-liquid reaction equipment according to any one of claims 1 to 2; wherein the liquid supply equipment is connected to the liquid inlet of the first storage tank through a pipeline, and the gas supply equipment is connected to the gas inlet of the gas distributor through a pipeline.

4. The system according to claim 3, characterized in that The gas outlet of the first storage tank is connected to the equipment of the downstream process through a pipeline, and a pressure gauge, a ratio meter and a valve are provided on the pipeline; a pressure gauge, a flow meter and a valve are provided on the pipeline between the gas supply equipment and the gas distributor.

5. A method for preparing barium carbonate, characterized in that: Using the gas-liquid reaction system described in claim 3 or 4, the liquid supply device supplies yellow water to the first storage tank, and the gas supply device supplies carbon dioxide or kiln gas to the gas distributor.

6. The method for preparing barium carbonate according to claim 5, characterized in that: The concentration of barium sulfide in the yellow water is 100-150 g / L, and the content of carbon dioxide in the kiln gas is 30%-40%.

7. The method for preparing barium carbonate according to claim 5 or 6, characterized in that: The reaction temperature of the yellow water and the carbon dioxide is 70-80° C., and the pressure of the system during the reaction is 0.20-0.60 MPa.

8. The method for preparing barium carbonate according to claim 7, characterized in that: The yellow water is washed with hydrogen sulfide before being pumped into the first storage tank.

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