A method and equipment for bleaching metatitanic acid in a sulfuric acid process for titanium dioxide

Abstract

The present invention provides a method and equipment for bleaching metatitanic acid in the sulfuric acid process for titanium dioxide. The present invention relates to the technical field of titanium compounds and includes the following steps: S1. A tail gas collection system is set up on the production line of sulfuric acid process titanium dioxide, and the acidolysis tail gas generated in the acidolysis and reduction steps is collected by the tail gas collection system; S2. The pretreated acidolysis tail gas is introduced into the metatitanic acid bleaching reactor for sufficient contact reaction to obtain bleaching tail gas; S3. The bleaching tail gas after sufficient contact reaction in step S2 is collected through a negative pressure device, and the collected bleaching tail gas is controlled to be further treated through an alkaline solution absorption tower to ensure that sulfur dioxide and nitrogen oxides in the tail gas are completely absorbed. The invention improves the utilization efficiency of the comprehensive resources of the tail gas and reduces the difficulty and cost of subsequent treatment of the tail gas.

Description

Technical Field

[0001] The present invention relates to the technical field of titanium compounds, and particularly to a method and equipment for bleaching metatitanic acid in a sulfuric acid process for titanium dioxide production. Background Art

[0002] Bleaching of metatitanic acid is another important step in titanium dioxide production, aiming to remove impurities in metatitanic acid and improve the whiteness and purity of the product. Traditional bleaching methods mostly use chemical reagents such as hydrogen peroxide, sodium hypochlorite, and trivalent titanium. Although these methods are effective, they are costly and may cause secondary pollution to the environment.

[0003] By collecting the acidolysis and titanium liquid reduction tail gases generated during the production process of sulfuric acid process titanium dioxide and applying them to the bleaching process of metatitanic acid, the resource utilization of the tail gas is realized, environmental pollution is reduced, and the product cost is lowered. However, as the bleaching process continues, the temperature in the tank continuously rises, and the iron impurity content in metatitanic acid gradually decreases. In the later stage of bleaching, it is difficult to fully utilize the heat and bleaching substances in the tail gas, reducing the comprehensive utilization efficiency of the tail gas and increasing the cost of final tail gas treatment. Summary of the Invention

[0004] In view of the above problems, the present invention provides a method and equipment for bleaching metatitanic acid in a sulfuric acid process for titanium dioxide production, which improves the comprehensive resource utilization efficiency of the tail gas and reduces the difficulty and cost of subsequent tail gas treatment.

[0005] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A method for bleaching metatitanic acid in a sulfuric acid process for titanium dioxide production includes the following steps: S1. Set up a tail gas collection system on the sulfuric acid process titanium dioxide production line, and use the tail gas collection system to collect the acidolysis tail gas generated in the acidolysis and reduction steps; S2. Introduce the pretreated acidolysis tail gas into the metatitanic acid bleaching reactor for full contact reaction to obtain bleaching tail gas; S3. The bleaching tail gas after full contact reaction in step S2 is collected through a negative pressure device, and the collected bleaching tail gas is further treated through an alkali liquor absorption tower to ensure that sulfur dioxide and nitrogen oxides in the tail gas are completely absorbed. Among them, the metatitanic acid bleaching reactor includes reactor one and reactor two, and the acidolysis tail gas is controlled to alternately pass through reactor one and reactor two for full contact reaction and then be collected through a negative pressure device.

[0007] Preferably, in step S1, the collected acidolysis tail gas is pretreated through an electrostatic precipitator to remove particulate matter in the acidolysis tail gas.

[0008] Preferably, in step S2, the flow rate of the acidolysis tail gas is controlled to be 800 cubic meters - 1500 cubic meters per hour.

[0009] A titanic acid bleaching device in a sulfuric acid titanium dioxide process is used in the above-mentioned titanic acid bleaching method in the sulfuric acid titanium dioxide process, comprising a titanic acid bleaching reactor, the titanic acid bleaching reactor comprising a reaction tank body, a tail gas inlet pipe is arranged at the bottom of the reaction tank body, and a tail gas exhaust pipe is installed on the side wall, the titanic acid bleaching reactor comprises a reactor one and a reactor two, the bottoms of the reactor one and the reactor two are commonly connected with a tail gas control device, and the tops of the reactor one and the reactor two are connected with a tail gas regulating device; a hollow stirring device is installed inside the reaction tank body, the bottom of the stirring device is connected with the tail gas inlet pipe, and the top is connected with the tail gas regulating device, an exhaust blade is installed on the side wall of the bottom of the stirring device, and a three-way control valve group is installed between the top of the stirring device and the tail gas regulating device, the conduction state of the three-way control valve group and the tail gas control device is adjusted, and the acid hydrolysis tail gas is controlled to pass through the reactor one and the reactor two alternately in sequence to fully contact and react before being collected.

[0010] Preferably, the stirring device includes a hollow stirring shaft, the outlet blades are installed on the bottom side wall of the stirring shaft, a conduction control valve body is installed inside the stirring shaft to adjust the flow direction of exhaust gas inside the stirring shaft, the conduction control valve body includes a columnar conduction control valve core and limit rings installed on both sides of the columnar conduction control valve core, a control chamber is formed between the two limit rings, and the outlet blades are connected to the control chamber.

[0011] Preferably, the three-way control valve group includes a three-way control valve body, a side wall of the three-way control valve body is installed with an air inlet connector connected to the interior of the reaction tank body, and a three-way control valve core is rotatably connected to the interior of the three-way control valve body. Rotating the three-way control valve core in a first state controls the exhaust gas regulating device to be connected to the stirring device, and rotating the three-way control valve core in a second state controls the exhaust gas regulating device to be connected to the interior of the reaction tank body.

[0012] Preferably, the tail gas exhaust pipe has a built-in on-off valve, and the on-off valve is linked with the corresponding three-way control valve group for control.

[0013] Preferably, the exhaust gas regulating device comprises an exhaust gas regulating pipeline, and the exhaust gas regulating pipeline has an air guide pump body built in it.

[0014] Preferably, a driving device is installed on the top of the reaction tank body, and the driving device includes a driving assembly connected to the stirring shaft and a driving motor for controlling the rotation of the driving assembly.

[0015] Preferably, the exhaust gas control device comprises a main air intake pipe and an exhaust gas control valve body, and exhaust gas is transported to different exhaust gas intake pipes through the exhaust gas control valve body.

[0016] The beneficial effects of the present invention are:

[0017] Compared with the prior art, in the first stage, the waste heat in the tail gas can be fully utilized in the above-mentioned manner to preheat the subsequent reactor, shorten the time required for its subsequent temperature rise, and improve the rate of metatitanic acid bleaching. In the second stage, the waste heat can also be used to maintain the temperature in the subsequent reactor, ensuring that both reactors are at appropriate temperatures for efficient bleaching of metatitanic acid. At the same time, through the above structural design, the subsequent reactor can be used to fully absorb the bleaching substances in the tail gas, improving the utilization efficiency of comprehensive resources and reducing the difficulty and cost of subsequent tail gas treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional structural schematic diagram of the present invention.

[0019] Figure 2 For the present invention Figure 1 is a front view structural schematic diagram.

[0020] Figure 3 It is a three-dimensional structural schematic diagram of the metatitanic acid bleaching reactor of the present invention.

[0021] Figure 4 For the present invention Figure 3 is a top view structural schematic diagram.

[0022] Figure 5 For the present invention Figure 4 is a sectional structural schematic diagram taken along the A-A direction.

[0023] Figure 6 It is an internal structural schematic diagram of the metatitanic acid bleaching reactor when the three-way control valve core of the present invention is in the second state.

[0024] Figure 7 It is a schematic diagram of different states of the conduction control valve body of the present invention.

[0025] Figure 8 For the present invention Figure 5 is an enlarged structural schematic diagram at position B.

[0026] Figure 9 For the present invention Figure 6 is an enlarged structural schematic diagram at position C.

[0027] In the figure: 100, metatitanic acid bleaching reactor; 1001, reactor one; 1002, reactor two; 110, reaction tank body; 111, tail gas exhaust pipe; 112, bottom discharge pipe; 113, tail gas inlet pipe; 114, top connecting pipe; 120, driving device; 121, driving motor; 122, driving component; 130, stirring device; 131, stirring rotating shaft; 132, stirring blades; 133, air outlet blades; 1331, blade body; 1332, air outlet holes; 200, tail gas control device; 210, main inlet pipe; 220, tail gas control valve body; 300, tail gas regulating device; 400, three-way control valve group; 410, three-way control valve body; 411, first joint; 412, inlet joint; 413, second joint; 420, three-way control valve core; 421, rotation control rotating shaft; 500, conduction control valve body; 510, limiting ring; 520, conduction control valve core. Detailed implementation manners

[0028] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0029] During the production process of sulfuric acid process titanium dioxide, acidolysis and reduction are two key steps, and a large amount of tail gas will be generated in this process, mainly including harmful gases such as sulfur dioxide (SO 2 ), nitrogen oxides (NOx), sulfuric acid mist, hydrogen sulfide, etc. The emission of these tail gases not only causes serious pollution to the environment, but also wastes the potential resources therein; currently, the treatment of these tail gases in industry mostly adopts the traditional washing and absorption method, but this method has a high cost and cannot effectively recover the useful components in the tail gas.

[0030] Metatitanic acid bleaching is another important step in the production of titanium dioxide, and its purpose is to remove impurities in metatitanic acid and improve the whiteness and purity of the product. Traditional bleaching methods mostly use chemical reagents such as hydrogen peroxide, sodium hypochlorite, trivalent titanium, etc. Although these methods are effective, they have a high cost and may cause secondary pollution to the environment.

[0031] By collecting the acidolysis and titanium liquid reduction tail gases generated during the production process of sulfuric acid process titanium dioxide and applying them to the bleaching process of metatitanic acid, the resource utilization of the tail gas can be realized, environmental pollution can be reduced, and the product cost can be lowered; however, as the bleaching process continues, the temperature in the tank continues to rise, and the iron impurity content in metatitanic acid gradually decreases. In the later stage of bleaching, it is difficult to make full use of the heat and bleaching substances in the tail gas, which reduces the comprehensive utilization efficiency of the tail gas and also increases the cost of final tail gas treatment.

[0032] In order to solve the above problems, a method for bleaching metatitanic acid in a sulfuric acid process titanium dioxide process includes the following steps;

[0033] S1. Set up an exhaust gas collection system on the sulfuric acid process titanium dioxide production line, and use the exhaust gas collection system to collect the acid digestion exhaust gas generated in the acid digestion and reduction steps; in step S1, the collected acid digestion exhaust gas is pretreated through an electrostatic precipitator to remove particulate matter in the acid digestion exhaust gas. In this way, particulate matter in the exhaust gas can be effectively removed, preventing new impurities from mixing into the metatitanic acid, and also avoiding affecting the normal operation inside the bleaching equipment.

[0034] S2. Introduce the pretreated acid digestion exhaust gas into the metatitanic acid bleaching reactor 100 for sufficient contact reaction to obtain bleaching exhaust gas; during this process, control the flow rate of the acid digestion exhaust gas to be 800 cubic meters - 1500 cubic meters per hour to achieve efficient utilization of the exhaust gas, control the efficient heating of the metatitanic acid exhaust gas to the bleaching temperature, and accelerate the rate of removing internal impurities.

[0035] S3. The bleaching exhaust gas after sufficient contact reaction in step S2 is collected through a negative pressure device, and control the collected bleaching exhaust gas to be further treated through an alkaline solution absorption tower to ensure that sulfur dioxide and nitrogen oxides in the exhaust gas are completely absorbed.

[0036] Among them, the metatitanic acid bleaching reactor 100 includes reactor one 1001 and reactor two 1002. Control the acid digestion exhaust gas to alternately pass through reactor one 1001 and reactor two 1002 in sequence for sufficient contact reaction and then be collected through a negative pressure device.

[0037] For example, in the first stage, first control the high-temperature exhaust gas to enter reactor one 1001 from the bottom. The metatitanic acid in reactor one 1001 can make sufficient contact with the high-temperature exhaust gas to achieve efficient bleaching; the temperature of the bleached exhaust gas in reactor one 1001 decreases, and this part of the exhaust gas is discharged to the bottom of reactor two 1002. The metatitanic acid in reactor two 1002 can fully absorb the remaining temperature of this part of the exhaust gas for preheating.

[0038] As the bleaching process in reactor one 1001 continues, while the temperature in reactor one 1001 gradually rises, the iron-containing impurities in the metatitanic acid gradually decrease; after reacting for a certain time, enter the second stage. At this time, the direction of the exhaust gas pump can be switched, and the initial high-temperature exhaust gas is introduced into reactor two 1002 to increase the rate of temperature rise in reactor two 1002 and accelerate the removal of iron impurities in the metatitanic acid in reactor two 1002; and at this time, the bleached exhaust gas in reactor two 1002 is introduced to the bottom of reactor one 1001. Reactor one 1001 can absorb the remaining exhaust gas after one-time bleaching again, maintain the increased temperature in reactor one 1001, and fully absorb the remaining part of the bleaching substances to avoid waste of resources.

[0039] By controlling the state of the tail gas switching, reasonably controlling the bleaching time and state of the tail gas in Reactor 1 (1001) and Reactor 2 (1002), and finally controlling the relative synchronous bleaching of metatitanic acid in Reactor 1 (1001) and Reactor 2 (1002), the efficient utilization of this part of the tail gas is achieved.

[0040] In summary, through the above method, in the first stage, the waste heat in the tail gas can be fully utilized to preheat the subsequent reactor, shortening the time required for its subsequent temperature rise, and improving the bleaching rate of metatitanic acid. In the second stage, the waste heat can also be used to maintain the temperature in the subsequent reactor, ensuring that both reactors are at an appropriate temperature for efficient bleaching of metatitanic acid. At the same time, through the above structural design, the subsequent reactor can be used to fully absorb the bleaching substances in the tail gas, improving the utilization efficiency of comprehensive resources, and reducing the difficulty and cost of subsequent tail gas treatment.

[0041] The following further illustrates this method with specific embodiments. Embodiment

[0042] 1. In a sulfuric acid process titanium dioxide production line, a tail gas collection system is set up to collect the tail gas generated in the acid digestion and reduction steps.

[0043] 2. The collected tail gas is pretreated by an electrostatic precipitator to remove the particulate matter therein.

[0044] 3. The pretreated tail gas is introduced into the first metatitanic acid bleaching reactor. The flow rate of the tail gas is controlled at 1000 cubic meters per hour. After reacting with metatitanic acid for 30 minutes, the reaction temperature is measured to be 60°C. After continuing the reaction for 1 hour, the reaction temperature is measured to be 67°C. Subsequently, the tail gas is introduced into the second metatitanic acid bleaching reactor and continues to react for 1 hour.

[0045] 4. The tail gas that has been fully bleached by metatitanic acid is collected by a negative pressure device and further treated through an alkaline solution absorption tower to ensure that sulfur dioxide, nitrogen oxides, etc. in the tail gas are completely absorbed.

[0046] 5. The bleached metatitanic acid is washed with water. After the washing is completed, the iron content in the metatitanic acid is detected to be 43 ppm, and the L value detected by a whiteness meter is 98.51, both of which meet the product standards. Embodiment

[0047] 1. In a sulfuric acid process titanium dioxide production line, a tail gas collection system is set up to collect the tail gas generated in the acid digestion and reduction steps.

[0048] 2. The collected tail gas is pretreated by an electrostatic precipitator to remove the particulate matter therein.

[0049] 3. Introduce the purified tail gas into the first metatitanic acid bleaching reactor, control the flow rate of the tail gas at 1500 cubic meters per hour, and after fully contacting and reacting with the metatitanic acid for 30 minutes, the reaction temperature is measured to be 64 °C. Continue the reaction for 1 hour, and the reaction temperature is measured to be 70 °C. Subsequently, introduce the tail gas into the second metatitanic acid bleaching reactor and continue the reaction for 1 hour.

[0050] 4. The tail gas fully bleached by the metatitanic acid is collected by a negative pressure device and further treated through an alkali liquor absorption tower to ensure that sulfur dioxide, nitrogen oxides, etc. in the tail gas are completely absorbed.

[0051] 5. Wash the bleached metatitanic acid. After the washing is completed, the iron content in the metatitanic acid is detected to be 36 ppm, and the L value detected by a whiteness meter is 98.93, both meeting the product standards. Example

[0052] 1. On the sulfuric acid process titanium dioxide production line, set up a tail gas collection system to collect the tail gas generated in the acid digestion and reduction steps.

[0053] 2. Pretreat the collected tail gas through an electrostatic precipitator to remove the particulate matter therein.

[0054] 3. Introduce the purified tail gas into the first metatitanic acid bleaching reactor, control the flow rate of the tail gas at 800 cubic meters per hour, and after fully contacting and reacting with the metatitanic acid for 30 minutes, the reaction temperature is measured to be 57 °C. Continue the reaction for 1 hour, and the reaction temperature is measured to be 62 °C. Subsequently, introduce the tail gas into the second metatitanic acid bleaching reactor and continue the reaction for 1 hour.

[0055] 4. The tail gas fully bleached by the metatitanic acid is collected by a negative pressure device and further treated through an alkali liquor absorption tower to ensure that sulfur dioxide, nitrogen oxides, etc. in the tail gas are completely absorbed.

[0056] 5. Wash the bleached metatitanic acid. After the washing is completed, the iron content in the metatitanic acid is detected to be 58 ppm, and the L value detected by a whiteness meter is 97.88, meeting the product standards.

[0057] The following further explains the equipment used in the above method.

[0058] Refer to the appendix Figure 1 - Appendix Figure 9, A metatitanic acid bleaching device in a sulfuric acid process for titanium dioxide, including a metatitanic acid bleaching reactor 100. The metatitanic acid bleaching reactor 100 includes a reaction tank body 110. A tail gas inlet pipe 113 is provided at the bottom of the reaction tank body 110, and a tail gas exhaust pipe 111 is installed on the side wall. The tail gas enters the reaction tank body 110 from the tail gas inlet pipe 113 and can fully contact and bleach the metatitanic acid. After the tail gas exhaust pipe 111 is opened, the fully contacted tail gas can be discharged from the tail gas exhaust pipe 111 to ensure the pressure balance in the reaction tank body 110 and ensure the production and transportation of the tail gas. A bottom discharge pipe 112 is also installed at the bottom of the side wall of the reaction tank body 110.

[0059] Furthermore, the metatitanic acid bleaching reactor 100 here includes a reactor one 1001 and a reactor two 1002. A tail gas control device 200 is commonly connected to the bottoms of the reactor one 1001 and the reactor two 1002, and a tail gas regulating device 300 is connected to the tops of the reactor one 1001 and the reactor two 1002. Through the tail gas regulating device 300, the tail gas after one-time bleaching can be introduced to the bottom position of the latter reactor for secondary utilization; the acid hydrolysis tail gas is controlled to alternately pass through the reactor one 1001 and the reactor two 1002 in sequence and is fully contacted and reacted and then collected. Through the above design, the acid hydrolysis tail gas can pass through different reactors successively, and the heat and bleaching substances of the acid hydrolysis tail gas can be fully utilized.

[0060] A hollow stirring device 130 is installed inside the reaction tank body 110. The bottom of the stirring device 130 is connected to the tail gas inlet pipe 113, and the top is connected to the tail gas regulating device 300. Air outlet blades 133 are installed on the side wall of the bottom of the stirring device 130. During the continuous rotation of the air outlet blades 133, while stirring the mixed medium in the reaction tank body 110, the surface of the air outlet blades 133 can continuously discharge the tail gas, which can fully contact the mixed medium in the reaction tank body 110 and achieve full bleaching of the metatitanic acid.

[0061] A three-way control valve group 400 is installed between the top of the stirring device 130 and the tail gas regulating device 300. The conduction states of the three-way control valve group 400 and the tail gas control device 200 are adjusted to control the acid hydrolysis tail gas to alternately pass through the reactor one 1001 and the reactor two 1002 in sequence and be fully contacted and reacted and then collected.

[0062] For example, control the three-way control valve group 400 in the reactor one 1001 to be in the attached Figure 9 shown state, and the three-way control valve group 400 in the reactor two 1002 to be in the attached Figure 8The state shown; the tail gas is pumped into the outlet blade 133 at the bottom of the first reactor 1001 through the tail gas control device 200 and discharged. During the upward flow of the tail gas, it can come into full contact with metatitanic acid to achieve bleaching. And the first reactor 1001 is controlled to be in a closed state. The tail gas in the first reactor 1001 passes through the intake joint 412 and enters the tail gas regulating device 300. Since the three-way control valve group 400 in the second reactor 1002 is in the Figure 8 state shown, the tail gas after the pressure increases can pass through the stirring rotating shaft 131 and be discharged from the outlet blade 133 at the bottom of the second reactor 1002. While the metatitanic acid in the second reactor 1002 can fully absorb the remaining heat in the tail gas, it can also fully absorb some of the later residual reducing substances, improving the efficiency of comprehensive resource utilization. The tail gas after being absorbed again has a low temperature and low internal reducing substances, reducing the burden of subsequent treatment; the tail gas exhaust pipe 111 on the side wall of the top of the second reactor 1002 is controlled to be in an open state, and the tail gas that has been fully bleached twice can be discharged from the tail gas exhaust pipe 111 for subsequent in-depth treatment.

[0063] After a certain period of time after the tail gas control device 200 pumps the tail gas into the first reactor 1001, the tail gas control device 200 is controlled to pump the tail gas into the bottom of the second reactor 1002, and the conduction states of the three-way control valve groups 400 in the first reactor 1001 and the second reactor 1002 are swapped with each other. The flow path of the tail gas is opposite to the above process and finally discharged from the tail gas exhaust pipe 111 at the top of the latter reactor to achieve subsequent in-depth treatment.

[0064] Through this device, the efficient and full utilization of the tail gas can be realized; there is no need to set multiple groups of complex pipelines in the two reactors. The gas exchange control can be realized through a set of pipelines and two three-way control valve groups 400, reducing the difficulty of equipment installation in the reaction tank body 110, shortening the flow path of the tail gas, and improving the utilization efficiency of the tail gas.

[0065] It should be noted here that the structures in contact with the tail gas and metatitanic acid need to be treated with corrosion resistance to extend the service life of the overall equipment.

[0066] Specifically; the stirring device 130 includes a hollow stirring rotating shaft 131. The outlet blade 133 is installed on the bottom side wall of the stirring rotating shaft 131. Stirring blades 132 are also installed on the surface of the stirring rotating shaft 131 above the outlet blade 133, which can fully stir the mixed medium and improve the efficiency of tail gas bleaching.

[0067] A conduction control valve body 500 is installed inside the stirring shaft 131 to adjust the exhaust gas flow direction inside the stirring shaft 131. The conduction control valve body 500 can control the exhaust gas at the top or bottom to enter the exhaust blade 133 in an orderly manner, avoiding extending the exhaust gas flow path too long to ensure that the exhaust gas can be discharged in time, thereby further improving the efficiency of exhaust gas bleaching.

[0068] Specifically, the conduction control valve body 500 includes a columnar conduction control valve core 520 and a limit ring 510 installed on both sides of the columnar conduction control valve core 520. A control chamber is formed between the two limit rings 510. The air outlet blade 133 is connected to the control chamber. The air outlet blade 133 here includes a blade body 1331 and an air outlet hole 1332. The control chamber can be in a connected state with multiple air outlet holes 1332. At the same time, a one-way valve group is installed inside the air outlet blade 133 to prevent titanic acid from flowing in reverse and entering the stirring shaft 131.

[0069] The conduction control valve core 520 and the inner wall of the stirring shaft 131 are in a relatively sealed sliding state, which increases the air pressure of the bottom exhaust gas and can push the conduction control valve core 520 to move upward. The conduction control valve core 520 and the upper limiting ring 510 can be in a sealed state to prevent the exhaust gas from continuing to flow upward and can be discharged from the outer air outlet 1332 in time; similarly, after the exhaust gas enters the top, the conduction control valve core 520 is in a tight state with the lower limiting ring 510 under the combined action of the exhaust gas and gravity, controlling the exhaust gas entering from the top to be quickly discharged from the outer air outlet 1332.

[0070] Specifically, the three-way control valve group 400 includes a three-way control valve body 410, and the side wall of the three-way control valve body 410 is installed with an air inlet joint 412 connected to the inside of the reaction tank body 110, and the top of the three-way control valve body 410 is provided with a first joint 411 connected to the exhaust gas regulating device 300, and the first joint 411 is connected to the exhaust gas regulating device 300 through the top connecting pipe 114, and the bottom of the three-way control valve body 410 is provided with a second joint 413 connected to the stirring shaft 131, and the second joint 413 is connected to the stirring shaft 131 through a rotating sealing connector; a three-way control valve core 420 is rotatably connected inside the three-way control valve body 410, and the rotating three-way control valve core 420 is in a first state to control the exhaust gas regulating device 300 to be connected with the stirring device 130, that is, in the attached Figure 8 Rotate the three-way control valve core 420 in the second state to control the exhaust gas regulating device 300 and the reaction tank body 110 is connected to the inside, that is, in the attached Figure 9 Status shown.

[0071] According to different stages of exhaust emission, the conduction state of the three-way control valve core 420 is adjusted to change the direction of exhaust emission, form a passage for one-way flow of exhaust gas, avoid exhaust gas crossing, and ensure sufficient double bleaching of titanic acid.

[0072] An on-off valve is built into the tail gas exhaust pipe 111, and the on-off valve is linked with the corresponding three-way control valve group 400 to control the three-way control valve core 420 in the reactor to be in the adjacent Figure 8 In the first state shown, the corresponding tail gas exhaust pipe 111 is synchronously controlled to be in an open state, so that the tail gas after two bleaching processes can be discharged, and the three-way control valve core 420 in the reactor is controlled to be in an adjacent state. Figure 9 In the second state shown, the corresponding exhaust gas exhaust pipe 111 is synchronously controlled to be in a closed state to prevent the exhaust gas that has undergone one bleaching from being discharged from the exhaust gas exhaust pipe 111, and the exhaust gas that has undergone one bleaching is controlled to pass through the air inlet connector 412 into the exhaust gas regulating device 300 and be introduced into the next reactor for secondary bleaching.

[0073] The opening and closing valve and the three-way control valve group 400 can be synchronously controlled by an electric switch, or collaboratively controlled by a hydraulic system. Through the above-mentioned structural design, synchronous control of the internal system of the pipeline can be achieved, reducing the operating burden of the staff.

[0074] The exhaust gas regulating device 300 includes an exhaust gas regulating pipeline, which has an internal air pump body. The exhaust gas that has undergone one bleaching in the reactor can be discharged and sucked in from the air inlet joint 412 through the air pump body, and the sucked exhaust gas is pumped into the bottom of the second reactor after being pressurized and discharged. Through the above-mentioned structural design, the flow rate of the exhaust gas can be accelerated, which is particularly suitable for reactors with larger volume and greater depth. The exhaust gas can be discharged after being pressurized, ensuring that the exhaust gas can normally enter the bottom of the reactor, reducing the continuous increase in the internal pressure of the reactor, and ensuring the safe bleaching.

[0075] A driving device 120 is installed on the top of the reaction tank body 110. The driving device 120 includes a driving component 122 connected to the stirring shaft 131 and a driving motor 121 for controlling the rotation of the driving component 122. The driving component 122 can be used to offset the driving motor 121 and install it on the outside, so that the power can be transmitted to the stirring shaft 131 in time to control the rotation of the stirring shaft 131, thereby achieving sufficient stirring of the titanic acid in the reactor and disturbing the exhaust gas to improve the exhaust gas bleaching effect. The driving component 122 here can be selected as an existing gear component or a belt transmission component.

[0076] The tail gas control device 200 includes a main intake pipe 210 and a tail gas control valve body 220. The tail gas is conveyed into different tail gas intake pipes 113 through the tail gas control valve body 220. The above-mentioned tail gas control valve body 220 can also be synchronously controlled with the opening and closing valves. The control personnel only need to control the tail gas to enter the corresponding reactor, then the synchronous adjustment control of the valves in the two reactors can be completed, further reducing the operation burden of the staff, avoiding accidents and improving work efficiency.

[0077] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A titanic acid bleaching device in a sulfuric acid titanium dioxide process, comprising a titanic acid bleaching reactor (100), wherein the titanic acid bleaching reactor (100) comprises a reaction tank body (110), wherein a tail gas inlet pipe (113) is arranged at the bottom of the reaction tank body (110), and a tail gas exhaust pipe (111) is installed on the side wall, wherein: The metatitanic acid bleaching reactor (100) comprises a reactor 1 (1001) and a reactor 2 (1002); the bottoms of the reactor 1 (1001) and the reactor 2 (1002) are connected to a tail gas control device (200); the tops of the reactor 1 (1001) and the reactor 2 (1002) are connected to a tail gas regulating device (300); A hollow stirring device (130) is installed inside the reaction tank body (110); the bottom of the stirring device (130) is connected to the exhaust gas inlet pipeline (113), and the top is connected to the exhaust gas regulating device (300); an exhaust blade (133) is installed on the side wall of the bottom of the stirring device (130); a three-way control valve group (400) is installed between the top of the stirring device (130) and the exhaust gas regulating device (300); the conduction state of the three-way control valve group (400) and the exhaust gas control device (200) is adjusted to control the acid hydrolysis exhaust gas to alternately pass through the reactor 1 (1001) and the reactor 2 (1002) in sequence, and then pass through different reactors in succession to fully contact and react with metatitanic acid of different temperatures and concentrations before being collected; The stirring device (130) comprises a hollow stirring shaft (131), the outlet blade (133) is mounted on the bottom side wall of the stirring shaft (131), a conduction control valve body (500) is mounted inside the stirring shaft (131) for adjusting the exhaust gas flow direction inside the stirring shaft (131), the conduction control valve body (500) comprises a columnar conduction control valve core (520) and limit rings (510) mounted on both sides of the columnar conduction control valve core (520), a control chamber is formed between the two limit rings (510), and the outlet blade (133) is connected to the control chamber; The three-way control valve group (400) comprises a three-way control valve body (410), a side wall of the three-way control valve body (410) is provided with an air inlet joint (412) connected to the interior of the reaction tank body (110), and a three-way control valve core (420) is rotatably connected to the interior of the three-way control valve body (410). When the three-way control valve core (420) is rotated to a first state, the exhaust gas regulating device (300) is controlled to be connected to the stirring device (130), and when the three-way control valve core (420) is rotated to a second state, the exhaust gas regulating device (300) is controlled to be connected to the interior of the reaction tank body (110); the acid hydrolysis exhaust gas is controlled to pass through the reactor 1 (1001) and the reactor 2 (1002) alternately in sequence for sufficient contact reaction before being collected.

2. The metatitanic acid bleaching equipment in the sulfuric acid titanium dioxide process according to claim 1, characterized in that: The tail gas exhaust pipe (111) has a built-in on-off valve, and the on-off valve is controlled in linkage with the corresponding three-way control valve group (400).

3. The metatitanic acid bleaching equipment in the sulfuric acid titanium dioxide process according to claim 1, characterized in that: The exhaust gas regulating device (300) comprises an exhaust gas regulating pipeline, wherein an air guide pump body is built into the exhaust gas regulating pipeline.

4. The metatitanic acid bleaching equipment in the sulfuric acid titanium dioxide process according to claim 1, characterized in that: A driving device (120) is installed on the top of the reaction tank body (110), and the driving device (120) comprises a driving component (122) connected to the stirring shaft (131) and a driving motor (121) for controlling the rotation of the driving component (122).

5. The metatitanic acid bleaching equipment in the sulfuric acid titanium dioxide process according to claim 1, characterized in that: The exhaust gas control device (200) comprises a main air intake pipe (210) and an exhaust gas control valve body (220), and exhaust gas is transported to different exhaust gas intake pipes (113) via the exhaust gas control valve body (220).

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