Method for producing titanium dioxide
The precise control of the growth process of titanium dioxide particles through the segmented reaction mode, the problems of poor spherical morphology and wide particle size distribution in the existing titanium dioxide process of chlorination are solved, and the precise control of particle size and process energy saving and consumption reduction are achieved. effect.
Patent Information
- Application Number
- CN202411669904.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-21
- Publication Date
- 2025-02-18
AI Technical Summary
In the existing titanium dioxide process of chloride method, the titanium dioxide particles have poor spherical shape, wide particle size distribution, and waste of energy and coolant during the reaction process.
The segmented reaction mode is adopted. The first high-temperature reaction produces small particles of titanium dioxide, the second rapidly cools down to avoid sintering, and the third phase uses the heat generated by the high-temperature segment to make the small particles continue to grow to a suitable particle size.
It realizes precise control of the particle size of titanium dioxide particles, with narrow particle size distribution, better spherical shape, and more energy-saving and consumption-reducing process.
Smart Images
Figure CN119461473A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of titanium dioxide production, and in particular relates to a control method for producing different types of titanium dioxide, and more particularly, to a method for producing titanium dioxide. Background Art
[0002] Titanium dioxide is a powder material. Its particle size and particle size distribution are the most important indicators that determine the quality of the product, and directly affect the pigment performance and application performance of titanium dioxide. There are three preparation processes for titanium dioxide used in industrial production: sulfuric acid titanium dioxide, chloride titanium dioxide and hydrochloric acid titanium dioxide. Among them, chloride titanium dioxide is favored by users because of its short process, less three wastes, and narrow product particle size distribution. It accounts for the largest proportion of the three processes. Chloride titanium dioxide is usually prepared by high-temperature and instantaneous reaction of gas-phase titanium tetrachloride and oxygen in a reactor. That is, the reactor is instantaneously completed at high temperature including nucleation, condensation, aggregation, fusion, adsorption, desorption and many other processes, followed by the addition of a large amount of coolant to rapidly cool down and stop crystal growth to obtain the initial titanium dioxide product. However, the initial titanium dioxide product obtained by this method has poor sphericity, a relatively wide particle size distribution, and the reaction process is prone to waste of energy and coolant. Summary of the invention
[0003] In view of the defects of the above-mentioned prior art, the purpose of the present invention is to provide a method for producing titanium dioxide, which adopts a staged reaction mode. The first stage is a high-temperature reaction to produce small particles of titanium dioxide, the second stage quickly drops to below the sintering temperature to avoid sintering of small particles, and the third stage uses the heat generated in the high-temperature stage to allow the small particles to continue to grow to a suitable particle size. The present invention allows the particle size of titanium dioxide particles to be precisely controlled, and various types of products can be produced by adjusting materials, temperature, etc., and the particle size distribution is narrow.
[0004] The difference between the present invention and the conventional method is that the conventional method has only one reaction zone, in which the reaction material is introduced, the reaction is completed and the particles are cooled quickly to stop the reaction, and the particles obtained are titanium dioxide. The particle size distribution of titanium dioxide particles prepared by the conventional method does not have time for homogenization, and the titanium dioxide particles are unevenly distributed. The method disclosed in the present invention provides homogenization conditions for titanium dioxide particles, making the particles more uniform and better in sphericity.
[0005] In order to solve the above technical problems or achieve the above objectives, the present invention adopts the following technical solutions, which are specifically described as follows: According to one aspect of the present invention, there is provided a method for producing titanium dioxide, comprising the following steps: 1) Aluminum trichloride, titanium tetrachloride, oxygen, potassium chloride and water are introduced into the first reactor to react at a temperature of 1300-1800°C to generate small-size titanium dioxide particles; 2) introducing small-size titanium dioxide particles into the second reactor and rapidly cooling them to 900-1000°C to obtain a rapidly cooled material; 3) Introducing the quenched material into the third reactor, controlling the cooling rate of the third reactor to maintain the temperature at 750-1000°C, and effectively controlling the growth of the titanium dioxide particles by temperature and time to obtain titanium dioxide particles with appropriate particle size; 4) Cooling the titanium dioxide particles with appropriate particle size to below 200°C and obtaining the titanium dioxide product through post-processing.
[0006] In one embodiment of the present invention, in step 1), titanium tetrachloride and aluminum trichloride are preheated to 440-500° C. in a preheater and then introduced into the first reactor.
[0007] In one embodiment of the present invention, in step 1), oxygen is preheated to 700-900° C. in another preheater and then introduced into the first reactor.
[0008] In one embodiment of the present invention, titanium tetrachloride and aluminum trichloride are introduced into the first reactor simultaneously with oxygen.
[0009] In one embodiment of the present invention, in step 1), potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and then introduced into the first reactor.
[0010] In one embodiment of the present invention, in step 1), the particle size of the small-size titanium dioxide particles is in the range of 160-210 nm.
[0011] In one embodiment of the present invention, in step 2), the small-size titanium dioxide particles are rapidly cooled to 900-1000° C. by a coolant and a water-cooling jacket.
[0012] In one embodiment of the present invention, in step 3), the cooling rate of the third reactor is controlled at 5-30° C. / min.
[0013] In one embodiment of the present invention, in step 3), the particle size of the titanium dioxide particles with a suitable particle size ranges from 200 to 240 nm.
[0014] In one embodiment of the present invention, in step 4), the titanium dioxide particles with a suitable particle size are cooled to below 200° C. through a tubular heat exchanger.
[0015] By adopting the above technical solution, the present invention has the following advantages compared with the prior art: The present invention adopts a staged reaction mode to accurately control the growth process of titanium dioxide particles, avoid high-temperature sintering, and utilize the heat generated by the reaction to promote the crystal to complete processes such as coagulation and fusion. No additional equipment and instruments are needed, and accurate control of the particle size of titanium dioxide particles can be achieved by adjusting process parameters. Compared with the existing process, the present invention is more energy-saving and consumption-reducing, has broad prospects for promotion and application, and has significant economic and social benefits. The particle size distribution of the prepared titanium dioxide particles is narrower. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The above and / or additional aspects and advantages of the present invention will be more obvious and easily understood in the description of the embodiments in conjunction with the accompanying drawings, in which: Figure 1 A schematic flow chart of a method for producing titanium dioxide provided by the present invention is shown. DETAILED DESCRIPTION
[0017] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.
[0018] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.
[0019] like Figure 1 As shown, the present invention provides a method for producing titanium dioxide, comprising the following steps: S101: introducing aluminum trichloride, titanium tetrachloride, oxygen, potassium chloride and water into a first reactor, and reacting at a temperature of 1300-1800° C. to generate small-size titanium dioxide particles; S102: introducing small-size titanium dioxide particles into the second reactor, and rapidly cooling to 900-1000° C. to obtain a rapidly cooled material; S103: introducing the quenched material into the third reactor, controlling the cooling rate of the third reactor to maintain the temperature at 750-1000° C., and effectively controlling the growth degree of the titanium dioxide particles by temperature and time to obtain titanium dioxide particles with appropriate particle size; S104: Cool the titanium dioxide particles with appropriate particle size to below 200° C. and obtain a titanium dioxide product through post-processing.
[0020] The present invention adopts a staged reaction mode to accurately control the growth process of titanium dioxide particles, avoid high-temperature sintering, and utilize the heat generated by the reaction to promote the crystal to complete processes such as coagulation and fusion. No additional equipment and instruments are needed, and accurate control of the particle size of titanium dioxide particles can be achieved by adjusting process parameters. Compared with the existing process, the present invention is more energy-saving and consumption-reducing, has broad prospects for promotion and application, and has significant economic and social benefits. The particle size distribution of the prepared titanium dioxide particles is narrower.
[0021] In the above method for producing titanium dioxide, in step S101, titanium tetrachloride and aluminum trichloride are preheated to 440-500° C. in a preheater and then introduced into a first reactor.
[0022] In the above method for producing titanium dioxide, in step S101, oxygen is preheated to 700-900° C. in another preheater and then introduced into the first reactor.
[0023] In the above method for producing titanium dioxide, titanium tetrachloride and aluminum trichloride are introduced into the first reactor simultaneously with oxygen.
[0024] In the above method for producing titanium dioxide, in step S101, potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and then introduced into the first reactor.
[0025] In the above method for producing titanium dioxide, in step S101, the particle size range of the obtained small-size titanium dioxide particles is 160-210 nm.
[0026] In the above method for producing titanium dioxide, in step S102, the small-size titanium dioxide particles are rapidly cooled to 900-1000° C. by a coolant and a water-cooling jacket.
[0027] In the above method for producing titanium dioxide, in step S103, the cooling rate of the third reactor is controlled at 5-30°C / min.
[0028] In the above method for producing titanium dioxide, in step S103, the particle size range of the obtained titanium dioxide particles with a suitable particle size is 200-240 nm.
[0029] In the above method for producing titanium dioxide, in step S104, titanium dioxide particles with a suitable particle size are cooled to below 200° C. through a tubular heat exchanger.
[0030] The above technical solution of the present invention is described in detail below through specific embodiments.
[0031] The embodiment of the present invention discloses a method for producing titanium dioxide. The method adopts a staged reaction mode. The first stage is a high-temperature reaction to produce small particles of titanium dioxide. The second stage quickly drops to below the sintering temperature to avoid sintering of small particles. The third stage uses the heat generated in the high-temperature stage to allow the small particles to continue to grow to a suitable particle size. The present invention allows the particle size of titanium dioxide to be accurately controlled. By adjusting the materials, temperature, etc., various types of products can be produced, and the particle size distribution is narrow. The difference between the present invention and the usual method is that there is usually only one reaction zone, and the reaction material is introduced into the reaction zone. After the reaction is completed, the particles are quickly cooled to stop the particles from continuing to react, and the particles obtained are titanium dioxide. The particle size distribution of titanium dioxide prepared by the ordinary method does not have time for homogenization, and the titanium dioxide particles are unevenly distributed. The method disclosed in the present invention provides homogenization conditions for titanium dioxide, making the particles more uniform and having better sphericity.
[0032] The specific steps of the method for producing titanium dioxide are as follows: First, aluminum trichloride, titanium tetrachloride, oxygen, potassium chloride and water are introduced into the first reactor of the first stage, and react at a temperature of 1300-1800°C to generate small-size titanium dioxide particles; Next, the small-size titanium dioxide particles are introduced into the second reactor of the second stage, and rapidly cooled to 900-1000° C. to obtain a quenched material; Next, the quenched material is introduced into the third reactor of the third stage, and the cooling rate of the third reactor is controlled to maintain the temperature within the range of 750-1000°C. The growth degree of the titanium dioxide particles can be effectively controlled by temperature and time to obtain titanium dioxide particles with appropriate particle size. Finally, the titanium dioxide particles with suitable particle size enter the tubular heat exchanger from the third reactor and are cooled to below 200° C. to obtain a preliminary titanium dioxide product with suitable particle size, which is then post-processed to obtain a titanium dioxide product.
[0033] Among them, titanium tetrachloride and aluminum trichloride are preheated to 440-500° C. in a preheater and then introduced into the first reactor, oxygen is preheated to 700-900° C. in another preheater and simultaneously introduced into the first reactor, potassium chloride and water are configured into a potassium chloride solution of a certain concentration and introduced into the first reactor, and heat is provided to make the temperature of the reaction zone in the first reactor reach 1300-1800° C. The temperature of the reaction zone is higher than the sintering temperature of titanium dioxide particles. If the time required for particle growth is sufficient, the obtained titanium dioxide particles are uneven in size, hard, and have poor pigment properties. The present invention controls the time of the first reaction zone to be extremely short, and obtains small-diameter titanium dioxide particles with a particle size in the range of 160-210 nm; The small-sized titanium dioxide particles in the first reactor are introduced into the second reactor, and the small-sized particles are quickly cooled to a temperature range of 900-1000°C using cooling measures such as coolant and water-cooling jacket. The small-sized titanium dioxide particles whose temperature drops to 900-1000°C enter the third reactor.
[0034] By controlling the cooling rate of the third reactor, small-sized titanium dioxide particles are homogeneously grown to become large-sized titanium dioxide particles, and titanium dioxide particles with a suitable particle size of 200-240nm are obtained. The cooling rate of the third reactor is controlled at 5-30℃ / min. The third reactor does not need additional heating, and the heat brought by the material is sufficient to meet the energy for the continuous growth of the particles. The present invention makes full use of the heat of the reaction itself, fundamentally avoids the sintering of titanium dioxide particles, and provides time for the particles to grow, so that the obtained product has a narrow particle size distribution, uniform size, good sphericity, and excellent pigment performance.
[0035] Example 1 A method for producing titanium dioxide, the specific operating steps are as follows: Titanium tetrachloride and aluminum trichloride are heated to 480°C in a preheater and introduced into the first reactor. Oxygen is heated to 830°C in another preheater and introduced into the first reactor at the same time. Potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and pumped into the first reactor to provide heat so that the temperature of the reaction zone of the first reactor reaches 1600°C to generate small-sized titanium dioxide particles. The time of the first reaction zone is controlled to be extremely short to obtain small-sized titanium dioxide particles of about 170nm. The small-sized titanium dioxide particles in the first reactor are introduced into the second reactor, and the small-sized particles are quickly cooled to a temperature range of 900-1000°C by cooling measures such as coolants and water-cooled jackets. The materials are introduced into the third reactor, and the cooling rate of the third reactor is controlled to be 5°C / min. It takes 50 minutes to reduce the temperature from 1000°C to 750°C. The titanium dioxide particle size can be effectively controlled to grow to about 220nm through temperature and time. The prepared titanium dioxide particles with a particle size of 220 nm enter the tubular heat exchanger from the third reactor and are cooled to below 200° C., and then are post-treated to obtain a titanium dioxide product.
[0036] Example 2 In the preheater, titanium tetrachloride and aluminum trichloride are heated to 470℃ and introduced into the first reactor. In another preheater, oxygen is heated to 790℃ and introduced into the first reactor at the same time. Potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and pumped into the first reactor to provide heat so that the temperature of the reaction zone of the first reactor reaches 1800℃, generating small-sized titanium dioxide particles; the time of the first reaction zone is controlled to be extremely short, and small-sized titanium dioxide particles of about 165nm are obtained. The small-sized titanium dioxide particles in the first reactor are introduced into the second reactor, and the small-sized particles are quickly cooled to a temperature range of 900-1000℃ by cooling measures such as coolant and water-cooling jacket. The material is introduced into the third reactor, and the cooling rate of the third reactor is controlled to be 10℃ / min. It takes 25 minutes to reduce the temperature from 1000℃ to 750℃. The particle size of titanium dioxide can be effectively controlled to grow to about 200nm through temperature and time. The prepared titanium dioxide particles with a particle size of 200 nm enter the tubular heat exchanger from the third reactor and are cooled to below 200° C., and then are post-treated to obtain a titanium dioxide product.
[0037] Example 3 Titanium tetrachloride and aluminum trichloride are heated to 450°C in a preheater and introduced into the first reactor. Oxygen is heated to 800°C in another preheater and introduced into the first reactor at the same time. Potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and pumped into the first reactor to provide heat so that the temperature of the reaction zone of the first reactor reaches 1700°C to generate small-sized titanium dioxide particles. The time of the first reaction zone is controlled to be extremely short to obtain small-sized titanium dioxide particles of about 210nm. The small-sized titanium dioxide particles in the first reactor are introduced into the second reactor, and the small-sized particles are quickly cooled to a temperature range of 900-1000°C by cooling measures such as coolants and water-cooled jackets. The materials are introduced into the third reactor, and the cooling rate of the third reactor is controlled to be 25°C / min. It takes 10 minutes to reduce the temperature from 1000°C to 750°C. The particle size of titanium dioxide can be effectively controlled to grow to about 240nm through temperature and time. The prepared titanium dioxide particles with a particle size of 240 nm enter the tubular heat exchanger from the third reactor and are cooled to below 200° C., and then are post-treated to obtain a titanium dioxide product.
[0038] Example 4 Titanium tetrachloride and aluminum trichloride are heated to 500°C in a preheater and introduced into the first reactor. Oxygen is heated to 700°C in another preheater and introduced into the first reactor at the same time. Potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and pumped into the first reactor to provide heat so that the temperature of the reaction zone of the first reactor reaches 1300°C to generate small-sized titanium dioxide particles. The time of the first reaction zone is controlled to be extremely short to obtain small-sized titanium dioxide particles of about 160nm. The small-sized titanium dioxide particles in the first reactor are introduced into the second reactor, and the small-sized particles are quickly cooled to a temperature range of 900-1000°C by cooling measures such as coolants and water-cooled jackets. The materials are introduced into the third reactor, and the cooling rate of the third reactor is controlled to be 5°C / min. It takes 50 minutes to reduce the temperature from 1000°C to 750°C. The titanium dioxide particle size can be effectively controlled to grow to about 210nm through temperature and time. The prepared titanium dioxide particles with a particle size of 210 nm enter the tubular heat exchanger from the third reactor and are cooled to below 200° C., and then are post-treated to obtain a titanium dioxide product.
[0039] It can be seen from the above Examples 1-4 that the present invention adopts a staged reaction mode to accurately control the growth process of titanium dioxide particles, avoid high-temperature sintering, and utilize the heat generated by the reaction to promote the crystal to complete processes such as coagulation and fusion. There is no need to add additional equipment and instruments. The particle size of the titanium dioxide particles can be accurately controlled by adjusting the process parameters. The present invention is more energy-saving and consumption-reducing, has broad prospects for promotion and application, and has significant economic and social benefits. The particle size distribution of the prepared titanium dioxide particles is narrower.
[0040] It should be particularly pointed out that the various components or steps in the above-mentioned embodiments can be cross-linked, replaced, added, or deleted with each other. Therefore, the combinations formed by these reasonable arrangements and combinations should also fall within the scope of protection of the present invention, and the scope of protection of the present invention should not be limited to the embodiments.
[0041] The above are exemplary embodiments disclosed in the present invention. The order disclosed in the above embodiments of the present invention is for description only and does not represent the advantages and disadvantages of the embodiments. However, it should be noted that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope disclosed in the embodiments of the present invention (including the claims) is limited to these examples. Various changes and modifications may be made without departing from the scope defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.
[0042] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.
Claims
1. A method for producing titanium dioxide, characterized in that: The following steps are involved: 1) Aluminum trichloride, titanium tetrachloride, oxygen, potassium chloride and water are introduced into the first reactor to react at a temperature of 1300-1800°C to generate small-size titanium dioxide particles; 2) introducing small-size titanium dioxide particles into the second reactor and rapidly cooling them to 900-1000°C to obtain a rapidly cooled material; 3) Introducing the quenched material into the third reactor, controlling the cooling rate of the third reactor to maintain the temperature at 750-1000°C, and effectively controlling the growth of the titanium dioxide particles by temperature and time to obtain titanium dioxide particles with appropriate particle size; 4) Cooling the titanium dioxide particles with appropriate particle size to below 200°C and obtaining the titanium dioxide product through post-processing.
2. The method for producing titanium dioxide according to claim 1, characterized in that: In step 1), titanium tetrachloride and aluminum trichloride are preheated to 440-500° C. in a preheater and then introduced into the first reactor.
3. The method for producing titanium dioxide according to claim 2, characterized in that: In step 1), oxygen is preheated to 700-900° C. in another preheater and then introduced into the first reactor.
4. The method for producing titanium dioxide according to claim 3, characterized in that: Titanium tetrachloride and aluminum trichloride are introduced into the first reactor simultaneously with oxygen.
5. The method for producing titanium dioxide according to claim 1, characterized in that: In step 1), potassium chloride and water are prepared into a potassium chloride solution of a certain concentration and then introduced into the first reactor.
6. The method for producing titanium dioxide according to claim 1, characterized in that: In step 1), the particle size of the small-size titanium dioxide particles is in the range of 160-210 nm.
7. The method for producing titanium dioxide according to claim 1, characterized in that: In step 2), the small-sized titanium dioxide particles are rapidly cooled to 900-1000° C. by a coolant and a water-cooling jacket.
8. The method for producing titanium dioxide according to claim 1, characterized in that: In step 3), the cooling rate of the third reactor is controlled at 5-30°C / min.
9. The method for producing titanium dioxide according to claim 1, characterized in that: In step 3), the particle size of the titanium dioxide particles is in the range of 200-240 nm.
10. The method for producing titanium dioxide according to claim 1, characterized in that: In step 4), the titanium dioxide particles with a suitable particle size are cooled to below 200° C. through a tubular heat exchanger.