A titanium solution hydrolysis process and device

Abstract

The present invention relates to a titanium liquid hydrolysis process and device in the technical field of sulfuric acid process titanium dioxide production. The process includes primary boiling, primary boiling maintenance and ash change, induced ripening, secondary boiling and secondary boiling maintenance, and water dilution. In the present application, indirect steam heating is used during the heating processes of primary boiling and secondary boiling. By adopting a combination of time-sharing and step-by-step indirect steam heating and direct steam heating for hydrolysis, it can not only ensure the heat transfer efficiency but also effectively improve the problem of poor particle size distribution of metatitanic acid in the prior art. The operation is simple, and the pigment performance of the product can be improved. The device includes a hydrolysis tank body, and an indirect steam heating assembly is arranged inside the hydrolysis tank body. The indirect steam heating assembly includes a first steam inlet pipe, a steam discharge pipe, a number of vertically arranged N-shaped steam heat exchange pipes, a number of arc-shaped connecting pipes, and an annular condensation connecting pipe. This device can effectively prevent problems such as material "accumulation" and "scale formation", is convenient for cleaning, and has a high heat transfer efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of sulfuric acid process titanium dioxide production, and specifically relates to a titanium liquid hydrolysis process and device. Background Art

[0002] Hydrolysis is an extremely important step in the production of sulfuric acid process titanium dioxide. The particle size and its distribution of titanium white precursor metatitanic acid after titanium liquid hydrolysis have a very important impact on the pigment properties of the subsequent titanium dioxide crude product and even the finished product. At present, the sulfuric acid process titanium white hydrolysis processes mainly include the self-seeding method and the external seeding method. Due to advantages such as simple operation, high stability, high degree of automation control, low requirement for the concentration of hydrolyzed titanium liquid, and excellent product quality, the external seeding method is favored by titanium dioxide manufacturers. When the titanium liquid is concentrated to a certain concentration, to prevent premature hydrolysis, generally the indirect steam method is used to preheat the titanium liquid to a certain temperature, and then the titanium liquid is injected into the hydrolysis tank using a high-level tank, and then hydrolysis seeds are added to start hydrolysis. The main processes of titanium liquid hydrolysis include primary boiling, primary boiling retention and ash change, induction ripening, secondary boiling and secondary boiling retention, water dilution, etc. Preheating generally uses the indirect heating method, and currently domestic sulfuric acid process titanium dioxide producers mainly use the direct steam heating method for the entire process of the main process of titanium liquid hydrolysis. Compared with indirect steam heating, direct steam heating has better heat transfer efficiency. However, during the heating processes in the front stage of primary boiling and the front stage of secondary boiling of titanium liquid hydrolysis, the condensed water generated by direct steam heating will greatly dilute the titanium liquid. When directly heated to primary boiling, the concentration of the titanium liquid will be reduced by 5 - 10 g / L, and when heated to secondary boiling after ripening is completed, the concentration of the titanium liquid will be reduced by 3 - 6 g / L. Both stages will cause the hydrolysis rate to increase and become unstable, ultimately resulting in a wider and worse distribution of metatitanic acid particles, and a decrease in the brightness and whiteness of the titanium dioxide product.

[0003] In addition, the hydrolyzed material is a liquid with high viscosity and easy to scale. There are problems such as material accumulation and even "scaling" in the existing spiral annular coil steam heating device, which is difficult to clean. If the cleaning is not in place, it will also affect the quality of the next batch of products. At the same time, when steam enters the spiral annular coil for heating, the steam condensed water will be stored at the bottom layer of the spiral annular coil, which is not conducive to high-efficiency heat conduction. In the sulfuric acid process titanium white hydrolysis process, the concentrated titanium liquid undergoes hydrolysis, and the black titanium liquid is hydrolyzed into white metatitanic acid. Metatitanic acid is relatively viscous and easily scales in the sulfuric acid system, resulting in low heat transfer efficiency of the spiral annular coil heating method, easy scaling and accumulation, difficult to clean, and affecting product quality.

[0004] Therefore, it is urgently necessary to improve the existing titanium liquid hydrolysis process and device. Summary of the Invention

[0005] The object of the present invention is to solve the above technical problems. In order to make up for the impact of the direct steam heating method on product quality, in the main process of titanium liquid hydrolysis (from adding hydrolysis seeds to the end of hydrolysis, excluding the preheating stage), the present invention adopts a combination of indirect and direct steam heating to optimize the particle size distribution of the hydrolyzed material and improve the pigment properties such as the brightness and whiteness of titanium dioxide. At the same time, the indirect steam heating component in the titanium liquid hydrolysis device is improved, and a vertically designed N-shaped vertical ring pipe is adopted to solve the problems of easy scaling and difficult cleaning of the existing spiral annular coil pipes.

[0006] According to an object of the present application, a titanium liquid hydrolysis process is provided, including the following steps:

[0007] S1. Primary boiling: Add a concentrated titanium liquid at a certain temperature and concentration to the prepared hydrolysis seeds to obtain a mixed titanium liquid. Calculate according to TiO2, control the addition amount of hydrolysis seeds to account for 2-4% of the addition amount of the concentrated titanium liquid, and then heat with indirect steam for 20-30 min to raise the temperature of the mixed titanium liquid to primary boiling. During the temperature increase process, control the stirring rate at 160-180 r / min;

[0008] S2. Primary boiling retention and ash change: After primary boiling, switch the indirect steam heating to direct steam heating and continue to maintain a slightly boiling state for 30-60 min until the mixed titanium liquid changes from black to steel gray, which is the ash change;

[0009] S3. Inductive ripening: After determining that the mixed titanium liquid has undergone ash change, stop the direct steam heating, reduce the stirring rate to 100-120 r / min, and maintain it for 30-40 min for inductive ripening;

[0010] S4. Secondary boiling: After the inductive ripening ends, the temperature of the mixed titanium liquid is 92-100 °C. Raise the stirring rate to 160-180 r / min, turn on the indirect steam heating, and heat for 20-30 min to secondary boiling;

[0011] S5. Secondary boiling retention: After secondary boiling, maintain the stirring rate at 160-180 r / min, switch the indirect steam heating to direct steam heating, and keep the boiling state for 90-150 min;

[0012] S6. Dilution with water: Add a certain proportion of dilution water to promote the hydrolysis of metatitanic acid, control the TiO2 concentration of the hydrolyzed sample at the end to be 165-170 g / L, the stirring rate at 160-180 r / min, and stir for 60-90 min to end the whole hydrolysis process.

[0013] Preferably, in step S1, the temperature of the concentrated titanium liquid is 90-98 °C, and the concentration is 180-220 g / L calculated according to TiO2.

[0014] Preferably, in step S1, the temperature of the first boiling is 106 - 109°C.

[0015] In step S1 and step S4, the temperature of the second boiling is 108 - 112°C.

[0016] According to another object of the present application, a titanium liquid hydrolysis device is provided, which includes a hydrolysis tank body. An indirect steam heating component is provided inside the hydrolysis tank body. The indirect steam heating component includes a steam inlet pipe 1, a steam discharge pipe, several vertically arranged N-shaped steam heat exchange pipes, several arc-shaped connecting pipes, and an annular condensation connecting pipe. Several N-shaped steam heat exchange pipes and several arc-shaped connecting pipes are respectively evenly distributed circumferentially above the annular condensation connecting pipe. Among several N-shaped steam heat exchange pipes, there is an inlet steam N-shaped pipe and an outlet steam N-shaped pipe. The inlet of the inlet steam N-shaped pipe is connected to the steam inlet pipe 1 through an arc-shaped connecting pipe. The outlet of the outlet steam N-shaped pipe is connected to the steam outlet pipe through an arc-shaped connecting pipe. The inlet end of the steam inlet pipe 1 and the outlet end of the steam outlet pipe are both led to the outside of the hydrolysis tank body. The outlet of the inlet steam N-shaped pipe is connected to the inlet of its adjacent N-shaped steam heat exchange pipe through an arc-shaped connecting pipe. The inlet of the outlet steam N-shaped pipe is connected to the outlet of its adjacent N-shaped steam heat exchange pipe through an arc-shaped connecting pipe. The inlets and outlets of the remaining adjacent N-shaped steam heat exchange pipes are connected through the corresponding arc-shaped connecting pipes in sequence. Each arc-shaped connecting pipe has a water outlet at its lowest point. The water outlets are evenly distributed on the top of the annular condensation connecting pipe and are respectively connected to the annular condensation connecting pipe in a communicating manner. A drain pipe is provided on the side wall of the annular condensation connecting pipe. The end of the drain pipe that is hermetically penetrated to the outside of the hydrolysis tank body is provided with a drain valve.

[0017] Preferably, a steam inlet pipe 2 for direct steam heating is further provided on the hydrolysis tank body. The bottom of the steam inlet pipe 2 extends to the bottom of the mixed titanium liquid inside the hydrolysis tank body to ensure the heat exchange efficiency of direct steam heating.

[0018] Preferably, a stirring component is further provided inside the hydrolysis tank body. The stirring component does not interfere with the steam inlet pipe 2 and the indirect steam heating component to ensure the safe and stable operation of the device.

[0019] Preferably, the stirring component includes a stirring shaft and stirring blades provided on the stirring shaft. The stirring shaft hermetically penetrates the top cover of the hydrolysis tank body and is rotationally connected to the top cover. A stirring motor is provided on the top cover. The output shaft of the stirring motor is in transmission connection with the stirring shaft.

[0020] Preferably, the steam inlet pipe 1, the steam discharge pipe, and the steam inlet pipe 2 are all hermetically penetrated through the top cover.

[0021] The present invention also includes other steps, components or devices that enable its normal use, such as corresponding sensors for detecting the temperature, concentration and liquid level of materials, a timer for recording the corresponding time, an automatic valve that can realize the automatic switching between two steam heating methods, and a DCS system automatic control system, etc., all of which adopt conventional means in the art. In addition, devices or components not defined in the present invention, such as hydrolysis tanks, stirring shafts, stirring blades, stirring motors and drain valves, etc., all adopt the existing technologies in the art, and those skilled in the art can select the specifications and models of the corresponding components or devices according to actual needs.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The present invention has made an innovative improvement to the current direct steam heating method in the whole process of the main titanium liquid hydrolysis process. It adopts a combination of time-sharing and step-by-step indirect steam heating and direct steam heating for hydrolysis. During the process from adding hydrolysis seeds to the first boiling and from the end of induced ripening to the second boiling, the indirect steam heating method is adopted, which avoids the large decrease in the concentration of titanium liquid caused by direct steam heating in this process. Since the amount of steam required for the two boiling retention is less, it has basically no influence on the final particle size distribution of the hydrolysis material. It can not only ensure the heat transfer efficiency, but also effectively improve the problem that the direct steam condensation greatly dilutes the concentration of titanium liquid and leads to a poor particle size distribution of hydrolyzed metatitanic acid. The operation is simple, which is conducive to narrowing the particle size distribution of the product particles and improving the pigment performance of the product.

[0024] 2. For the current device or method of using a spiral annular coil for heat exchange in indirect steam heating, the material is likely to accumulate on each coil, and even "scale", which is difficult to clean. In the case of materials with higher viscosity and easier to scale, the situation is even worse. After improvement, a vertically designed N-shaped vertical ring pipe is adopted, which can effectively prevent problems such as material "accumulation" and "scaling", and is convenient for cleaning. At the same time, a ring-shaped condensate connecting pipe is arranged at the bottom of the hydrolysis tank to facilitate the condensate drainage operation outside the hydrolysis tank, which is beneficial to improving the heat transfer efficiency. By adopting the vertically designed N-shaped vertical ring pipe, the problem that the existing spiral annular coil is easy to scale and not easy to clean is solved. Description of the Drawings

[0025] Figure 1 It is a process flow schematic diagram of the present invention in Examples 1 to 3.

[0026] Figure 2 It is a layout structure schematic diagram of the N-shaped steam heat exchange pipe in the hydrolysis tank in Example 4.

[0027] Figure 3 It is an unfolded structure schematic diagram of the N-shaped steam heat exchange pipe in Example 4.

[0028] Figure 4It is a schematic structural diagram of the top cover in Embodiment 4. Specific embodiments

[0029] The following further elaborates on the technology of the present invention in conjunction with the accompanying drawings and specific embodiments.

[0030] Embodiment 1:

[0031] As Figure 1 shown, this embodiment proposes a titanium solution hydrolysis process, which includes the following steps:

[0032] S1. Primary boiling: Add the concentrated titanium solution at 90 - 98°C with a concentration of 180 - 220 g / L in terms of TiO2 to the prepared hydrolysis seeds to obtain a mixed titanium solution. The F value of the concentrated titanium solution is 1.80 - 2.10, Fe / TiO2 is 0.30 - 0.38, the stability is ≥500 ml. In terms of TiO2, control the addition amount of hydrolysis seeds to account for 2% of the addition amount of the concentrated titanium solution, and then indirectly heat with steam for 25 min to raise the temperature of the mixed titanium solution to 106°C for primary boiling. During the temperature rise process, control the stirring rate at 180 r / min;

[0033] S2. Primary boiling retention and color change: After primary boiling, switch the indirect steam heating to direct steam heating, and continue to maintain a slightly boiling state for 58 min until the mixed titanium solution changes from black to steel gray, which is the color change;

[0034] S3. Inductive ripening: After determining that the color change of the mixed titanium solution has occurred, stop the direct steam heating, reduce the stirring rate to 100 r / min, and maintain for 35 min for inductive ripening;

[0035] S4. Secondary boiling: After the inductive ripening ends, the temperature of the mixed titanium solution is 92 - 100°C. Raise the stirring rate to 180 r / min, turn on the indirect steam heating, and heat for 25 min to 109°C for secondary boiling;

[0036] S5. Secondary boiling retention: After secondary boiling, maintain the stirring rate at 180 r / min, switch the indirect steam heating to direct steam heating, and keep the boiling state for 120 min;

[0037] S6. Dilution with water: Add a certain proportion of dilution water to promote the hydrolysis of metatitanic acid, control the TiO2 concentration of the hydrolyzed sample at the end to be 165 - 170 g / L, the stirring rate at 180 r / min, and stir for 90 min to complete the whole hydrolysis process.

[0038] Embodiment 2:

[0039] Example 2 is only different from Example 1 in that: in step S1, the indirect steam heating time is 28 min, and the temperature of the first boiling is 107 °C; in step S2, the slightly boiling state is maintained for 55 min; in step S3, the maintaining time for induced ripening is 30 min, in step S4, the indirect steam heating time is 26 min, and the temperature of the second boiling is 110 °C; in step S5, the boiling state is maintained for 130 min; in step S6, the stirring time is 80 min.

[0040] Example 3:

[0041] Example 3 is only different from Example 1 in that: in step S1, the indirect steam heating time is 30 min; in step S2, the slightly boiling state is maintained for 41 min; in step S3, the maintaining time for induced ripening is 30 min, in step S4, the indirect steam heating time is 30 min; in step S5, the boiling state is maintained for 125 min; in step S6, the stirring time is 80 min.

[0042] Comparative Example 1:

[0043] Comparative Example 1 is only different from Example 1 in that: in step S1, the indirect steam heating is changed to direct steam heating, and the heating time is 20 min, and the temperature of the first boiling is 107 °C; in step S2, the slightly boiling state is maintained for 51 min; in step S3, the maintaining time for induced ripening is 40 min, in step S4, the indirect steam heating is changed to direct steam heating, and the heating time is 23 min, and the temperature of the second boiling is 108 °C; in step S5, the boiling state is maintained for 110 min; in step S6, the stirring time is 60 min.

[0044] Comparative Example 2:

[0045] Comparative Example 2 is only different from Comparative Example 1 in that: in step S1, the direct steam heating time is 23 min; in step S2, the slightly boiling state is maintained for 45 min; in step S3, the maintaining time for induced ripening is 32 min, in step S4, the direct steam heating time is 20 min, and the temperature of the second boiling is 109 °C; in step S5, the boiling state is maintained for 90 min; in step S6, the stirring time is 70 min.

[0046] After the hydrolysis in Examples 1-3 and Comparative Examples 1-2 is completed, the particle size distribution of the hydrolyzed sample (hydrolyzed material) is tested with a laser particle size analyzer, and the hydrolyzed samples of each example and comparative example are respectively subjected to steps such as first washing, bleaching, second washing, salt treatment, and calcination to obtain the corresponding titanium white kiln inferior products. The pigment properties of each tested titanium white kiln inferior product are tested with a differential colorimeter, and the test results are shown in the following table:

[0047]

[0048] Among them, D10 in the table represents the particle size with a cumulative particle distribution of 10%, D50 represents the particle size with a cumulative particle distribution of 50%, and D90 represents the particle size with a cumulative particle distribution of 90%; the diameter ratio represents the width of the particle size distribution, and the diameter ratio = (D90 - D10) / D50. The smaller the diameter ratio value, the narrower the particle size distribution. Through the above comparison, it can be seen that compared with the prior art, the diameter ratio of this application is significantly reduced, the particle size distribution of the particles becomes narrower, the hydrolysis rate of the hydrolyzed material is improved, and the color characteristics of the kiln product become better.

[0049] The present invention makes an innovative improvement on the current direct steam heating method in the whole process of the main hydrolysis process of titanium liquid. The hydrolysis is carried out by combining indirect steam heating and direct steam heating in a time-sharing and step-by-step manner. Indirect steam heating is used during the process from adding hydrolysis seeds to the first boiling and from the end of induced ripening to the second boiling, avoiding a significant decrease in the concentration of titanium liquid caused by direct steam heating in this process. Since the amount of steam required for the two boiling processes is small, it has basically no impact on the final particle size distribution of the hydrolyzed material. It can not only ensure the heat transfer efficiency but also effectively improve the problem that the large dilution of the titanium liquid concentration caused by the direct steam condensation results in a poor particle size distribution of the hydrolyzed metatitanic acid. The operation is simple, which is beneficial to narrowing the particle size distribution of the product and improving the pigment performance of the product.

[0050] Example 4:

[0051] Such as Figure 2 , Figure 3 and Figure 4As shown in the figure, this embodiment provides a titanium solution hydrolysis device, which includes a hydrolysis tank body 1. An indirect steam heating component is arranged inside the hydrolysis tank body. The indirect steam heating component includes a steam inlet pipe 1, a steam discharge pipe 3, a number of vertically arranged N-shaped steam heat exchange pipes 4, a number of arc-shaped connecting pipes 5, and an annular condensate connecting pipe 6. A number of N-shaped steam heat exchange pipes and a number of arc-shaped connecting pipes are respectively evenly distributed in the circumferential direction above the annular condensate connecting pipe. Among the number of N-shaped steam heat exchange pipes, there is an inlet steam N-shaped pipe and an outlet steam N-shaped pipe. The inlet of the inlet steam N-shaped pipe is connected to the steam inlet pipe 1 through an arc-shaped connecting pipe, and the outlet of the outlet steam N-shaped pipe is connected to the steam outlet pipe through an arc-shaped connecting pipe. The steam inlet end of the steam inlet pipe 1 and the steam outlet end of the steam outlet pipe are both led to the outside of the hydrolysis tank body. The outlet of the inlet steam N-shaped pipe is connected to the inlet of its adjacent N-shaped steam heat exchange pipe through an arc-shaped connecting pipe, and the inlet of the outlet steam N-shaped pipe is connected to the outlet of its adjacent N-shaped steam heat exchange pipe through an arc-shaped connecting pipe. The inlets and outlets of the remaining adjacent N-shaped steam heat exchange pipes are connected through the arc-shaped connecting pipes at the corresponding positions in sequence. A water outlet pipe 7 is provided at the lowest point of each arc-shaped connecting pipe. The water outlet pipes are evenly distributed on the top of the annular condensate connecting pipe and are respectively connected to the annular condensate connecting pipe in a communicating manner. A drain pipe 8 is provided on the side wall of the annular condensate connecting pipe. A drain valve 9 is provided at one end of the drain pipe that is hermetically penetrated to the outside of the hydrolysis tank body.

[0052] In this embodiment, a steam inlet pipe 2 for direct steam heating is further provided on the hydrolysis tank body. The bottom of the steam inlet pipe 2 extends to the bottom of the mixed titanium solution inside the hydrolysis tank body to ensure the heat exchange efficiency of direct steam heating. A stirring component (not shown in the figure) is further arranged inside the hydrolysis tank body. The stirring component does not interfere with the steam inlet pipe 2 and the indirect steam heating component to ensure the safe and stable operation of the device.

[0053] Specifically, the stirring component includes a stirring shaft and stirring blades arranged on the stirring shaft. The stirring shaft hermetically penetrates the top cover 11 of the hydrolysis tank body and is rotatably connected to the top cover. A stirring motor 12 is provided on the top cover. The output shaft of the stirring motor is in transmission connection with the stirring shaft. The steam inlet pipe 1, the steam discharge pipe, and the steam inlet pipe 2 are all hermetically penetrated through the top cover.

[0054] In view of the current device or method of using a spiral annular coil for heat exchange in indirect steam heating, where materials are likely to accumulate on each coil, or even "scale", making it difficult to clean. The situation is even worse when dealing with materials with higher viscosity and easier to scale. After improvement, a vertically designed N-shaped vertical ring pipe is adopted, which can effectively prevent problems such as material "accumulation" and "scaling", and is convenient for cleaning. At the same time, an annular condensate connecting pipe is arranged at the bottom of the hydrolysis tank body, which is convenient for draining condensate water outside the hydrolysis tank body and is beneficial to improving the heat transfer efficiency.

[0055] 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 titanium liquid hydrolysis device, comprising a hydrolysis tank body, wherein an indirect steam heating component is arranged in the hydrolysis tank body, and it is characterized in that: The indirect steam heating component includes a steam inlet pipe, a steam exhaust pipe, a plurality of vertically arranged N-type steam heat exchange pipes, a plurality of arc-shaped connecting pipes and an annular condensation connecting pipe. The plurality of N-type steam heat exchange pipes and the plurality of arc-shaped connecting pipes are evenly distributed above the annular condensation connecting pipe along the circumferential direction. The plurality of N-type steam heat exchange pipes include a steam inlet N-type pipe and a steam outlet N-type pipe. The inlet of the steam inlet N-type pipe is connected to the steam inlet pipe through a arc-shaped connecting pipe, and the outlet of the steam outlet N-type pipe is connected to the steam outlet pipe through a arc-shaped connecting pipe. The steam inlet end of the steam inlet pipe and the steam outlet end of the steam outlet pipe are both connected to the outside of the hydrolysis tank body. The outlet of the steam inlet N-type tube is connected to the inlet of the adjacent N-type steam heat exchange tube via an arc-shaped connecting tube, the inlet of the steam outlet N-type tube is connected to the outlet of the adjacent N-type steam heat exchange tube via an arc-shaped connecting tube, and the inlets and outlets of the remaining adjacent N-type steam heat exchange tubes are connected once through arc-shaped connecting tubes at corresponding positions, and a water outlet pipe is provided at the lowest point of each arc-shaped connecting tube, and each water outlet pipe is distributed on the top of the annular condensation connecting tube and is respectively connected to the annular condensation connecting tube, and a drain pipe is provided on the side wall of the annular condensation connecting tube, and a drain valve is provided at one end of the drain pipe that is sealed and penetrates to the outside of the hydrolysis tank body.

2. The titanium liquid hydrolysis device according to claim 1, wherein: The hydrolysis tank body is also provided with a second steam inlet pipe for direct steam heating, and the bottom of the second steam inlet pipe extends to the bottom of the mixed titanium liquid in the hydrolysis tank body.

3. The titanium liquid hydrolysis device according to claim 2, characterized in that: The hydrolysis tank is also provided with a stirring component, which does not interfere with the second steam inlet pipe and the indirect steam heating component.

4. The titanium liquid hydrolysis device according to claim 3, characterized in that: The stirring assembly includes a stirring shaft and a stirring blade arranged on the stirring shaft. The stirring shaft seal passes through the top cover of the hydrolysis tank body and is rotatably connected to the top cover. A stirring motor is arranged on the top cover, and the output shaft of the stirring motor is drivingly connected to the stirring shaft.

5. The titanium liquid hydrolysis device according to claim 4, characterized in that: The first steam inlet pipe, the steam exhaust pipe and the second steam inlet pipe are all sealed and penetrated on the top cover.

6. A titanium solution hydrolysis process, characterized in that, The titanium liquid hydrolysis device according to any one of claims 1 to 5 is used to hydrolyze the titanium liquid, and the method comprises the following steps: S1, primary boiling: adding the prepared hydrolysis seed to the concentrated titanium liquid of a certain temperature and a certain concentration to obtain a mixed titanium liquid, and controlling the amount of the hydrolysis seed to account for 2-4% of the amount of the concentrated titanium liquid according to TiO2, and then indirectly steam heating for 20-30 minutes to heat the mixed titanium liquid to primary boiling, and controlling the stirring rate to 160-180r / min during the heating process; S2. Maintain boiling and graying: After boiling once, switch the indirect steam heating to direct steam heating and continue to maintain a slight boiling state for 30 to 60 minutes until the mixed titanium liquid changes from black to steel gray, which is graying; S3, induced aging: after determining that the mixed titanium liquid has turned gray, stop direct steam heating, reduce the stirring rate to 100-120r / min, and maintain for 30-40min for induced aging; S4. Secondary boiling: After the induced ripening ends, the temperature of the mixed titanium solution is 92 - 100 °C. Increase the stirring rate to 160 - 180 r / min, turn on the indirect steam heating, and heat for 20 - 30 min until secondary boiling occurs. S5. Secondary boiling maintenance: After secondary boiling, maintain the stirring rate at 160 - 180 r / min, switch the indirect steam heating to direct steam heating, and keep the boiling state for 90 - 150 min. S6. Dilution with water: Add a certain proportion of dilution water to promote the hydrolysis of metatitanic acid. Control the TiO₂ concentration of the sample at the end of hydrolysis to be 165 - 170 g / L, with a stirring rate of 160 - 180 r / min. Stir for 60 - 90 min until the whole hydrolysis process ends.

7. The titanium solution hydrolysis process according to claim 6, characterized in that: In step S1, the temperature of the concentrated titanium solution is 90 - 98 °C, and the concentration, calculated as TiO₂, is 180 - 220 g / L.

8. The titanium liquid hydrolysis process according to claim 6, characterized in that: In step S1, the temperature of the first boiling is 106 - 109 °C.

9. The titanium liquid hydrolysis process according to claim 6, characterized in that: In step S4, the temperature of the secondary boiling is 108 - 112 °C.

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