Titanium dioxide surface modification reaction kettle and titanium dioxide production process method

Abstract

This application provides a titanium dioxide surface modification reactor and a titanium dioxide production process. The reactor includes: a reactor body; a controller connected to a first motor, a second motor, a pH monitor, a metering pump, and a solenoid valve; the controller is configured to: feed titanium dioxide raw materials into the reactor body; turn on the first and second motors to operate the high-shear emulsifier and axial flow agitator at a first set speed; add a coating agent to the reactor body and obtain the pH value of the titanium dioxide slurry in the reactor body; if the pH value is not within the set pH range, add an acid-base adjuster to the reactor body to bring the pH value within the set pH range; after the titanium dioxide raw materials are fed, adjust the speed of the high-shear emulsifier and axial flow agitator to a second set speed; after a set time, obtain the titanium dioxide product; thereby solving the problems of uneven stirring, inaccurate coating agent addition speed, and drastic pH fluctuations in current reactors.

Description

Technical Field

[0001] This application relates to the field of titanium dioxide production technology, and in particular to a titanium dioxide surface modification reactor and a titanium dioxide production process. Background Technology

[0002] Titanium dioxide, as an important white pigment, is widely used in coatings, plastics, papermaking, and inks. Its performance directly affects the weather resistance, hiding power, and optical effects of the end products. In the titanium dioxide production process, surface modification (coating) is a core step in improving product quality. By forming an inorganic or organic coating layer on the particle surface, its dispersibility, weather resistance, and compatibility with the substrate can be significantly improved. However, the coating process is extremely sensitive to reaction conditions, and the uniformity of the coating layer, thickness control, and particle agglomeration directly affect the application performance of titanium dioxide.

[0003] Currently, titanium dioxide coating technology mainly employs a reaction vessel for liquid-phase coating, using a stirring paddle to mix the materials and a metering pump to control the addition rate of the coating agent. Simultaneously, an acid-base adjuster is used to maintain a stable pH value in the reaction system. Specifically, a paddle or turbine stirrer is used to promote contact between the coating agent and titanium dioxide particles; different coating agents are added in stages using multi-stage metering pumps to control the coating layer structure; and an online pH sensor is linked to the feed pump to adjust the acid and base addition amounts in real time to maintain a stable reaction environment.

[0004] However, the current titanium dioxide coating process has flow dead zones, resulting in local concentrations of coating agent that are too high or too low, and significant differences in coating thickness. Furthermore, the metering pump is affected by fluid viscosity and pressure fluctuations, making it difficult to achieve precise control of the coating layer. Due to the lag in acid-base adjustment, the pH value of the reaction system fluctuates greatly, which can easily lead to particle agglomeration and coating layer defects. Summary of the Invention

[0005] This application provides a titanium dioxide surface modification reactor and a titanium dioxide production process to solve the technical problems of uneven stirring, inaccurate coating agent addition rate, and drastic pH fluctuation in existing reactors.

[0006] The first aspect of this application provides a titanium dioxide surface modification reactor, comprising: The vessel body has a feed inlet at its top; a high-shear emulsifier is located at the bottom of the vessel body and is connected to a first motor; and an axial flow stirring paddle is located in the middle of the vessel body and is connected to a second motor. A pH monitor is installed inside the reactor body and is used to obtain the pH value of the titanium dioxide slurry inside the reactor body. A metering pump, which is connected to the vessel body, is used to add a coating agent to the vessel body. An electromagnetic valve is connected to the vessel body and is used to add an acid-base regulator into the vessel body. A controller is connected to the first motor, the second motor, the pH monitor, the metering pump, and the solenoid valve; the controller is configured to: Titanium dioxide raw materials are fed into the reactor body through the feed inlet using titanium dioxide transport equipment; Turn on the first motor and the second motor to make the high-shear emulsifier and the axial flow agitator run at a first set speed; Turn on the metering pump to add a coating agent into the reactor body, and obtain the pH value of the titanium dioxide slurry in the reactor body; If the pH value is not within the set pH value range, the solenoid valve is opened to add an acid-base regulator into the reactor body to bring the pH value within the set pH value range. After the titanium dioxide raw material is fed in, the speed of the high-shear emulsifier and the axial flow agitator is adjusted to the second set speed; after a set time, the titanium dioxide product is obtained; the second set speed is less than the first set speed.

[0007] In some embodiments, a jacket is provided on the outside of the reactor body, and the jacket is used to fill steam or cooling water to regulate the temperature of the titanium dioxide slurry inside the reactor body.

[0008] In some embodiments, a plurality of temperature sensors are provided inside the reactor body, and the temperature sensors are located at different heights; the temperature sensors are used to obtain the temperature of the titanium dioxide slurry inside the reactor body.

[0009] In some embodiments, the controller is connected to the temperature sensor, and the controller is further configured to: The temperature data of the titanium dioxide slurry inside the reactor body is obtained; the temperature data is collected by several temperature sensors. Based on the temperature data, the average temperature value of the titanium dioxide slurry is calculated; Determine the set modification temperature of the titanium dioxide slurry; Adjust the air or water intake of the jacket to bring the average temperature to the set modification temperature according to the set heating rate.

[0010] In some embodiments, the titanium dioxide surface modification reactor further includes: An anti-swirling baffle is provided within the vessel body via a connecting device, with the anti-swirling baffle positioned opposite each other on both sides of the vessel body. A gap exists between the anti-swirling baffle and the vessel body to form a fluid channel, which is used to prevent swirling within the vessel body.

[0011] In some embodiments, a liquid level sensor is provided on the top of the reactor body, and the liquid level sensor is used to obtain the liquid level height of the titanium dioxide slurry inside the reactor body.

[0012] In some embodiments, the controller is connected to the liquid level sensor, and the controller is further configured to: Obtain the liquid level height of the titanium dioxide slurry inside the reactor body; If the liquid level is higher than the preset liquid level, the rotation speed of the high-shear emulsifier and the axial flow agitator is reduced.

[0013] In some embodiments, the controller is configured with a feeding parameter library, which stores feeding parameters for different oxide coatings; the feeding parameters are the dropping rate and dropping time of the coating agent being added to the reactor body. The controller is further configured to: Determine the material of the coating agent; Based on the material, determine the corresponding target feeding parameters; The metering pump is turned on to add the coating agent into the reactor body according to the target feeding parameters.

[0014] In some embodiments, the bottom of the vessel body is configured as a dish or a cone.

[0015] The second aspect of this application provides a titanium dioxide production process method, applied to a titanium dioxide surface modification reactor as described in any one of the first aspects above, comprising: Titanium dioxide raw materials are fed into the reactor body through the feed inlet using titanium dioxide conveying equipment; Turn on the first and second motors to make the high-shear emulsifier and axial flow agitator run at the first set speed; Turn on the metering pump to add coating agent into the reactor body, and obtain the pH value of the titanium dioxide slurry in the reactor body; If the pH value is not within the set pH value range, the solenoid valve is opened to add an acid-base regulator into the reactor body to bring the pH value within the set pH value range. After the cumulative flow of the metering pump reaches the set flow value, the speed of the high-shear emulsifier and the axial flow agitator is adjusted to the second set speed; after a set time, titanium dioxide product is obtained; the second set speed is less than the first set speed.

[0016] This application provides a titanium dioxide surface modification reactor and a titanium dioxide production process. The reactor includes: a reactor body with a feed inlet at the top; a high-shear emulsifier connected to a first motor at the bottom; an axial flow stirring paddle connected to a second motor at the middle of the reactor body; a pH monitor installed inside the reactor body for obtaining the pH value of the titanium dioxide slurry inside the reactor body; a metering pump connected to the reactor body for adding a coating agent to the reactor body; a solenoid valve connected to the reactor body for adding an acid-base regulator to the reactor body; and a controller connected to the first motor, the second motor, the pH monitor, the metering pump, and the solenoid valve. The controller is configured to: use a titanium dioxide transport device to feed titanium dioxide raw materials into the reactor body through the feed inlet; turn on the first motor and the second motor to make the high-shear emulsifier and the axial flow agitator run at a first set speed; turn on the metering pump to add a coating agent to the reactor body and obtain the pH value of the titanium dioxide slurry in the reactor body; if the pH value is not within the set pH value range, turn on the solenoid valve to add an acid-base regulator to the reactor body to make the pH value within the set pH value range; after the titanium dioxide raw materials are fed, adjust the speed of the high-shear emulsifier and the axial flow agitator to a second set speed; after a set time, obtain the titanium dioxide product; the second set speed is lower than the first set speed to solve the problems of uneven stirring, inaccurate coating agent addition speed, and drastic pH fluctuation in the current reactor. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the titanium dioxide surface modification reactor in this application.

[0019] Explanation of reference numerals in the attached figures: 1-Tank body; 11-Feed inlet; 12-Jacket; 2-High shear emulsifier; 21-First motor; 3-Axial flow agitator; 31-Second motor; 4-pH monitor; 5-Metering pump; 6-Solenoid valve; 7-Temperature sensor; 8-Anti-swirling baffle; 81-Connecting device; 9-Level sensor. Detailed Implementation

[0020] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0021] Because some technologies suffer from uneven stirring, inaccurate coating agent addition rate, and drastic pH fluctuations in the reaction vessel, this application provides a titanium dioxide surface modification reaction vessel and a titanium dioxide production process to address these issues. The titanium dioxide surface modification reaction vessel and titanium dioxide production process are described below: like Figure 1 The diagram shown is a schematic diagram of the titanium dioxide surface modification reactor in this application.

[0022] The first aspect of this application provides a titanium dioxide surface modification reactor, comprising: The reactor body 1 has a feed inlet 11 at its top and a high-shear emulsifier 2 at its bottom, which is connected to a first motor 21. An axial flow agitator 3 is located in the middle of the reactor body 1 and is connected to a second motor 31. The reactor body 1 is cylindrical and made of stainless steel. The high-shear emulsifier 2 has a rotational speed of 2900 rpm to 3500 rpm and is used to break up primary agglomerates (titanium dioxide slurry). The axial flow agitator 3 is of the folded-blade type, providing a strong axial flow to ensure overall circulation of the titanium dioxide slurry, achieving a synergistic mixing process from localized high-intensity shearing to global large-scale circulation.

[0023] The outer side of the reactor body 1 is provided with a jacket 12, which is used to fill steam or cooling water to adjust the temperature of the titanium dioxide slurry inside the reactor body 1.

[0024] A pH monitor 4 is installed inside the reactor body 1. The pH monitor 4 is used to obtain the pH value of the titanium dioxide slurry inside the reactor body 1. The pH monitor 4 is an industrial-grade pH monitor with a self-cleaning function. Industrial-grade pH monitors typically have stronger corrosion resistance and durability, can adapt to the complex chemical environment during titanium dioxide production, and their self-cleaning function further extends the service life of the electrodes, reducing equipment downtime and maintenance costs caused by electrode contamination or damage.

[0025] A metering pump 5 is connected to the vessel body 1 and is used to add a coating agent to the vessel body 1. The metering pump 5 can add the coating agent to the vessel body 1 in a precise metering manner. The coating agent includes sodium silicate, aluminum sulfate, etc.

[0026] Solenoid valve 6 is connected to the vessel body 1 and is used to add acid-base regulator to the vessel body 1. The opening degree of solenoid valve 6 can adjust the rate of acid-base regulator.

[0027] The controller stores a preset feeding curve (a composite curve consisting of time t, flow rate Q, and pH value). It has a built-in PID control module and fuzzy control algorithm, receives pH, temperature, and speed signals, and outputs them to the actuator.

[0028] The controller is connected to the first motor 21, the second motor 31, the pH monitor 4, the metering pump 5, and the solenoid valve 6; the controller is configured to: Titanium dioxide raw materials are fed into the reactor body 1 through the feed inlet 11 using titanium dioxide transport equipment.

[0029] Turn on the first motor 21 and the second motor 31 to make the high-shear emulsifier 2 and the axial flow agitator 3 run at a first set speed; the first set speed is the initial set speed, which can be manually selected and is not limited here.

[0030] Turn on the metering pump 5 to add a coating agent into the reactor body 1, and obtain the pH value of the titanium dioxide slurry in the reactor body 1.

[0031] If the pH value is not within the set pH range, the solenoid valve 6 is opened to add an acid-base regulator into the reactor body 1 to bring the pH value within the set pH range.

[0032] After the titanium dioxide raw material is fed in, the speed of the high-shear emulsifier 2 and the axial flow agitator 3 is adjusted to the second set speed; after a set time, the titanium dioxide product is obtained; the second set speed is less than the first set speed.

[0033] This application provides a reaction vessel for surface modification of titanium dioxide, and the specific implementation method is as follows: First, titanium dioxide slurry preparation is carried out: titanium dioxide raw materials are added into the titanium dioxide surface modification reactor. The controller controls the high-shear emulsifier 2 at the bottom of the reactor body 1 to run at high speed to achieve full dispersion, which is usually controlled within 15-30 minutes. Second, a heating curve is set. The controller adjusts the water or air intake of the jacket 12 to make the titanium dioxide slurry reach the modification temperature set by the process (e.g., 70°C-90°C), and the heating rate is maintained at 1-2°C / min. The controller starts the metering pump 5 according to the preset composite feeding curve (composed of time t, cumulative flow Q, and target pH value). The controller uses a "prediction and feedback" mode to estimate the pH change caused by the addition of the coating agent and starts the solenoid valve 6 in advance to ensure that the pH fluctuation range is within ±0.1. After the feeding is completed, the controller automatically reduces the stirring speed to a low-speed mode (30-60 rpm) to maintain a constant temperature environment for maturation, making the coating layer structure dense.

[0034] This application provides a titanium dioxide surface modification reactor. Through the deep integration of physical structure (multi-stage stirring and high shear) and logical algorithm (pH follow-up feedback and PID control), it effectively solves industry problems such as uneven slurry mixing and drastic chemical environment fluctuations during the titanium dioxide coating process. This device can significantly improve the coating density of titanium dioxide and product whiteness, dispersibility, and other indicators, which has important practical value for realizing high-end titanium dioxide production and energy conservation and emission reduction.

[0035] In this embodiment, a plurality of temperature sensors 7 are installed inside the reactor body 1, and the temperature sensors 7 are located at different heights. The temperature sensors 7 are used to acquire the temperature of the titanium dioxide slurry inside the reactor body 1. The temperature sensors 7 are PT100 sensors. The multiple temperature sensors 7 are set at different heights, and the temperature of the titanium dioxide slurry collected by the temperature sensors 7 at different heights can reflect the overall temperature of the titanium dioxide slurry.

[0036] In this embodiment, the controller is connected to the temperature sensor 7, and the controller is further configured to: The temperature data of the titanium dioxide slurry inside the reactor body 1 is obtained; the temperature data is collected by several temperature sensors 7; the temperature data are the temperature values ​​collected by temperature sensors 7 at different heights.

[0037] Based on the temperature data, the average temperature value of the titanium dioxide slurry is calculated.

[0038] The set modification temperature of the titanium dioxide slurry is determined; the modification temperature refers to the specific temperature range that needs to be maintained when the slurry undergoes surface modification (such as inorganic or organic coating) in the reactor during the wet coating process of titanium dioxide. This temperature is adjusted by introducing steam or cooling water through the jacket 12, and directly affects the chemical reaction rate between the coating agent and the surface of the titanium dioxide particles, the density of the coating layer structure, and the performance of the final product.

[0039] Adjust the air or water intake of the jacket 12 to bring the average temperature to the set modification temperature according to the set heating rate.

[0040] For example, the average temperature value is brought to the set modification temperature according to the set heating rate, which ensures that the overall temperature of the titanium dioxide slurry rises uniformly, effectively avoiding the agglomeration of titanium dioxide particles caused by local overheating and ensuring uniform deposition of the coating agent.

[0041] In this embodiment, the titanium dioxide surface modification reactor further includes: An anti-swirling baffle 8 is disposed inside the vessel body 1 via a connecting device 81, and the anti-swirling baffle 8 is disposed opposite to each other on both sides of the vessel body 1; there is a gap between the anti-swirling baffle 8 and the inner wall of the vessel body 1.

[0042] For example, a gap is left between the anti-swirling baffle 8 and the inner wall of the reactor body 1, forming a local flow channel. When the fluid passes through the gap, a velocity gradient is generated, promoting axial mixing and preventing excessively high or low local flow velocities. The presence of the anti-swirling baffle 8 causes the fluid to circulate axially (in the height direction), enhancing the uniformity of titanium dioxide material mixing. For example, in titanium dioxide slurry modification, the anti-swirling baffle 8 prevents the generation of swirling flow, preventing the coating agent from locally agglomerating due to swirling flow and ensuring uniform coating layer thickness. The gap between the anti-swirling baffle 8 and the reactor body 1 forms a fluid channel; this fluid channel is used to prevent swirling flow from occurring within the reactor body 1. The connecting device 81 is a stainless steel round rod, the length of which ensures that a fluid channel is formed between the anti-swirling baffle 8 and the inner wall, so as to eliminate the mixing dead angle on the back of the anti-swirling baffle 8 using shear flow, thereby preventing swirling flow from occurring within the reactor body 1.

[0043] In this embodiment, a liquid level sensor 9 is provided on the top of the reactor body 1, and the liquid level sensor 9 is used to obtain the liquid level height of the titanium dioxide slurry inside the reactor body 1.

[0044] The controller is connected to the liquid level sensor 9, and the controller is further configured to: Obtain the liquid level height of titanium dioxide slurry inside the reactor body 1.

[0045] If the liquid level is higher than the preset liquid level, the rotation speed of the high-shear emulsifier 2 and the axial flow agitator 3 shall be reduced.

[0046] Specifically, when the liquid level is higher than the preset liquid level, reducing the rotation speed of the high-shear emulsifier 2 and the axial flow agitator 3 can prevent the titanium dioxide slurry from overflowing and ensure process safety; by reducing the agitation speed, splashing and bubbles generated by high-speed agitation of the titanium dioxide slurry are reduced, thereby reducing the fluctuation range of the liquid level.

[0047] For example, when the liquid level is too high, a strong swirling flow easily forms around the impeller blades of the axial flow agitator 3, leading to local aggregation of the coating agent (such as excessively high concentration at the edge of the vessel), resulting in uneven coating layer thickness; titanium dioxide particles aggregate towards the vessel wall due to centrifugal force, reducing the dispersion in the central area. After the high-shear emulsifier 2 slows down, the shear force weakens, avoiding excessive breakage of the coating agent particles and ensuring the density of the coating layer; after the axial flow agitator 3 slows down, the axial flow weakens, but the radial mixing is enhanced, promoting the uniform distribution of the coating agent on the cross-section of the vessel.

[0048] In this embodiment, the controller is configured with a feeding parameter library, which is used to store feeding parameters for different oxide coatings; the feeding parameters are the dripping rate and dripping time of the coating agent being added into the reactor body 1.

[0049] The controller is further configured to: Determine the material of the coating agent; based on the material, determine the corresponding target feeding parameters.

[0050] The metering pump 5 is turned on to add the coating agent dropwise into the reactor body 1 according to the target feeding parameters. The frequency of the acid / base regulator metering pump is dynamically adjusted to keep the pH value during the reaction process within ±0.1 deviation range of the set point.

[0051] In this embodiment, the bottom of the vessel body 1 is configured as a dish or cone shape. This dish or cone shape at the bottom eliminates dead zones in the stirring process.

[0052] For example, the disc-shaped bottom of the reactor allows the titanium dioxide slurry to naturally converge towards the center under gravity, avoiding the low-flow-rate areas (dead corners) that are easily formed in right-angled structures. The radial flow generated by the impeller blades of the axial flow agitator 3 bounces back into axial flow at the bottom of the curved surface, enhancing the mixing efficiency in the vertical direction.

[0053] For example, a conical bottom allows titanium dioxide slurry to slide rapidly down an inclined plane under gravity, achieving complete evacuation even at low speeds. In the conical bottom region, the fluid generates a velocity gradient due to cross-sectional contraction, increasing local shear force by 20%-30%, which promotes the dispersion of the coating agent.

[0054] This application provides a titanium dioxide surface modification reactor, which has the following beneficial effects: Improved uniformity: Multi-stage stirring combined with high-shear technology ensures a uniform and dense coating layer on the surface of titanium dioxide particles.

[0055] Stable quality: Automated pH control eliminates reliance on human experience, and the standard deviation of coating thickness between batches is reduced by more than 50%.

[0056] Efficiency optimization: Precise feeding control shortens the reaction cycle and reduces the waste of chemical additives. It features overpressure alarm, dry-burn protection, and heat recovery logic, significantly reducing energy consumption in the production process.

[0057] This application provides a reaction vessel for surface modification of titanium dioxide, which has the following specific embodiments: Example 1: Manufacturing process of high weather-resistant inorganic coating of zirconium oxide (ZrO2).

[0058] Initial conditions: titanium dioxide slurry concentration 350 g / L, reaction temperature set at 75°C, target pH value controlled at 8.5.

[0059] Dispersion process: The bottom high-shear emulsifier 2 runs at 3400 rpm for 25 minutes to ensure that there are no visible particles in the titanium dioxide slurry.

[0060] Feed control: Turn on zirconium oxychloride metering pump 5 with an initial flow rate of 0.15 L / min, and use a three-stage incremental flow rate (0.15 L / min, 0.4 L / min, 0.6 L / min).

[0061] Follow-up performance: When the pH monitor 4 senses that the pH drops below 8.4 due to acidic zirconium oxychloride, the controller quickly activates the sodium hydroxide pump (solenoid valve 6) and accurately restores the pH to 8.5 through high-frequency pulse feeding.

[0062] Results analysis: The titanium dioxide surface is covered with a dense ZrO2 film of uniform thickness (about 4.2 nm), which improves the UV resistance by 30%.

[0063] Example 2: High-performance organic surface modification process using aluminate coupling agents.

[0064] Initial conditions: slurry concentration 400 g / L, reaction temperature set at 65°C, target pH value adjusted to 7.0.

[0065] Dispersion process: The bottom high-shear emulsifier 2 runs at 3000 rpm for 15 minutes, which, together with the middle axial flow agitator 3, creates violent turbulence.

[0066] Feeding control: Turn on the aluminate coupling agent emulsion metering pump 5, set a constant flow rate of 0.3L / min, and continuously add for 45min.

[0067] Follow-up performance: The controller monitors the current (torque) of the stirring motor in real time. When the viscosity of the slurry increases instantaneously due to organic coating, it automatically increases the drive frequency and adds a small amount of diluent to ensure that the pH always fluctuates between 7.0 and 0.1.

[0068] Results analysis: The modified titanium dioxide showed significantly enhanced dispersibility in general plastics (such as PE and PP), and the filtration pressure value was reduced to less than 20% of that of the original sample.

[0069] The second aspect of this application provides a titanium dioxide production process method, applied to a titanium dioxide surface modification reactor described in any of the above embodiments, comprising: Titanium dioxide raw materials are fed into the reactor body through the feed inlet using titanium dioxide conveying equipment; Turn on the first and second motors to make the high-shear emulsifier and axial flow agitator run at the first set speed; Turn on the metering pump to add coating agent into the reactor body, and obtain the pH value of the titanium dioxide slurry in the reactor body; If the pH value is not within the set pH value range, the solenoid valve is opened to add an acid-base regulator into the reactor body to bring the pH value within the set pH value range. After the cumulative flow of the metering pump reaches the set flow value (i.e., after the added coating agent reaches the production requirement), the speed of the high-shear emulsifier and the axial flow agitator is adjusted to the second set speed; after a set time, titanium dioxide product is obtained; the second set speed is less than the first set speed.

[0070] It is worth noting that the effects of the above method embodiments can be found in the effects of the above reaction vessel embodiments, and will not be repeated here.

[0071] The above detailed embodiments further illustrate the purpose, technical solution, and beneficial effects of the embodiments of this application. It should be understood that the above are merely specific embodiments of the embodiments of this application and are not intended to limit the protection scope of the embodiments of this application. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solutions of the embodiments of this application should be included within the protection scope of the embodiments of this application.

Claims

1. A titanium white powder surface modification reaction kettle, characterized in that, include: The vessel body (1) has a feed inlet (11) at the top; a high-shear emulsifier (2) is provided at the bottom of the vessel body (1), and the high-shear emulsifier (2) is connected to a first motor (21); an axial flow stirring paddle (3) is provided in the middle of the vessel body (1), and the axial flow stirring paddle (3) is connected to a second motor (31). pH monitor (4), the pH monitor (4) is installed inside the reactor body (1), the pH monitor (4) is used to obtain the pH value of the titanium dioxide slurry inside the reactor body (1); Metering pump (5), the metering pump (5) is connected to the vessel body (1), the metering pump (5) is used to add coating agent to the vessel body (1); Solenoid valve (6), which is connected to the vessel body (1), is used to add acid-base regulator into the vessel body (1); The controller is connected to the first motor (21), the second motor (31), the pH monitor (4), the metering pump (5), and the solenoid valve (6); the controller is configured to: Titanium dioxide raw materials are fed into the reactor body (1) through the feed inlet (11) using titanium dioxide transport equipment; Turn on the first motor (21) and the second motor (31) to make the high shear emulsifier (2) and the axial flow agitator (3) run at a first set speed; Turn on the metering pump (5) to add coating agent into the reactor body (1) and obtain the pH value of titanium dioxide slurry in the reactor body (1); If the pH value is not within the set pH value range, the solenoid valve (6) is opened to add acid-base regulator to the reactor body (1) so that the pH value is within the set pH value range; After the titanium dioxide raw material is fed, the speed of the high shear emulsifier (2) and the axial flow stirring paddle (3) is adjusted to the second set speed; After a set time, the titanium dioxide product is obtained; the second set rotation speed is less than the first set rotation speed.

2. The titanium dioxide surface modification reaction kettle according to claim 1, characterized in that, A jacket (12) is provided on the outside of the reactor body (1), and the jacket (12) is used to fill steam or cooling water to adjust the temperature of the titanium dioxide slurry inside the reactor body (1).

3. The titanium dioxide surface modification reaction kettle according to claim 2, characterized in that, The reactor body (1) is equipped with several temperature sensors (7), and the temperature sensors (7) are located at different heights. The temperature sensors (7) are used to obtain the temperature of the titanium dioxide slurry inside the reactor body (1).

4. The titanium dioxide surface modification reaction kettle according to claim 3, characterized in that, The controller is connected to the temperature sensor (7), and the controller is further configured to: The temperature data of the titanium dioxide slurry inside the reactor body (1) is obtained; the temperature data is collected by several temperature sensors (7); Based on the temperature data, the average temperature value of the titanium dioxide slurry is calculated; Determine the set modification temperature of the titanium dioxide slurry; Adjust the air or water intake of the jacket (12) to reach the set modification temperature by adjusting the average temperature value according to the set heating rate.

5. The titanium dioxide surface modification reaction kettle according to claim 1, characterized in that, Also includes: Anti-swirling baffle (8) is installed inside the vessel body (1) via a connecting device (81). The anti-swirling baffle (8) is disposed opposite to each other on both sides of the vessel body (1). A gap is formed between the anti-swirling baffle (8) and the vessel body (1) to form a fluid channel. The fluid channel is used to prevent swirling from occurring inside the vessel body (1).

6. The titanium dioxide surface modification reaction kettle according to claim 1, characterized in that, A liquid level sensor (9) is provided on the top of the reactor body (1), and the liquid level sensor (9) is used to obtain the liquid level height of the titanium dioxide slurry inside the reactor body (1).

7. The titanium dioxide surface modification reaction kettle according to claim 6, characterized in that, The controller is connected to the liquid level sensor (9), and the controller is further configured to: Obtain the liquid level height of titanium dioxide slurry inside the reactor body (1); If the liquid level is greater than the preset liquid level, the rotation speed of the high shear emulsifier (2) and the axial flow agitator (3) shall be reduced.

8. The titanium dioxide surface modification reactor according to claim 1, characterized in that, The controller is equipped with a feeding parameter library, which is used to store feeding parameters for different oxide coatings; the feeding parameters are the dropping rate and dropping time of the coating agent being added into the reactor body (1); The controller is further configured to: Determine the material of the coating agent; Based on the material, determine the corresponding target feeding parameters; Turn on the metering pump (5) and add the coating agent into the vessel body (1) according to the target feeding parameters.

9. The titanium dioxide surface modification reactor according to claim 1, characterized in that, The bottom of the vessel body (1) is set in a dish shape or a cone shape.

10. A titanium dioxide production process, applied to a titanium dioxide surface modification reactor as described in any one of claims 1 to 9, characterized in that, include: Titanium dioxide raw materials are fed into the reactor body through the feed inlet using titanium dioxide conveying equipment; Turn on the first and second motors to make the high-shear emulsifier and axial flow agitator run at the first set speed; Turn on the metering pump to add coating agent into the reactor body, and obtain the pH value of the titanium dioxide slurry in the reactor body; If the pH value is not within the set pH value range, the solenoid valve is opened to add an acid-base regulator into the reactor body to bring the pH value within the set pH value range. Once the cumulative flow of the metering pump reaches the set flow value, the speed of the high-shear emulsifier and the axial flow agitator is adjusted to the second set speed. After a set time, the titanium dioxide product is obtained; the second set rotation speed is less than the first set rotation speed.

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