阅读说明：本技术 硫酸法钛白粒径的控制方法 (Method for controlling particle size of titanium dioxide by sulfuric acid process ) 是由 袁立军 景建林 淦文军 柳令 冯燕 罗静 于 2020-12-15 设计创作，主要内容包括：本发明涉及化工领域,具体涉及一种钛白粉粒径的控制方法。本发明所要解决的技术问题是提供一种硫酸法钛白粉粒径的控制方法,包括以下步骤：将偏钛酸打成浆料,加入煅烧晶种5.8～6.2％、锌盐0.12～0.28％、磷酸盐0.27～0.53％、钾盐0.17～0.43％,然后煅烧至金红石含量98.0～99.5％即可。通过上述方法,能够制备得到平均粒径在200～250纳米的钛白产品。(The invention relates to the field of chemical industry, in particular to a method for controlling particle size of titanium dioxide. The invention aims to solve the technical problem of providing a method for controlling the particle size of titanium dioxide by a sulfuric acid method, which comprises the following steps: beating metatitanic acid into slurry, adding 5.8-6.2% of calcined seed crystal, 0.12-0.28% of zinc salt, 0.27-0.53% of phosphate and 0.17-0.43% of potassium salt, and then calcining until the rutile content is 98.0-99.5%. By the method, the titanium dioxide product with the average particle size of 200-250 nanometers can be prepared.)

1. The method for controlling the particle size of the titanium dioxide by the sulfuric acid method is characterized by comprising the following steps: the method comprises the following steps: beating metatitanic acid into slurry, adding 5.8-6.2% of calcined seed crystal, 0.12-0.28% of zinc salt, 0.27-0.53% of phosphate and 0.17-0.43% of potassium salt, and then calcining until the rutile content is 98.0-99.5%.

2. The method for controlling the particle size of the sulfuric acid method titanium dioxide according to claim 1, characterized in that: when adding calcined seed crystal 6 + -0.2%, zinc salt 0.15 + -0.03%, phosphate 0.3 + -0.03%, potassium salt 0.2 + -0.03%, to obtain 210 + -10 nm sulfuric acid method titanium dioxide powder with a ratio of more than or equal to 80%.

3. The method for controlling the particle size of the sulfuric acid method titanium dioxide according to claim 1, characterized in that: when adding calcined seed crystal 6 + -0.2%, zinc salt 0.25 + -0.03%, phosphate 0.5 + -0.03%, potassium salt 0.4 + -0.03%, preparing to obtain 240 + -10 nm sulfuric acid method titanium dioxide powder with the ratio more than or equal to 80%.

4. The method for controlling the particle size of the sulfuric acid process titanium dioxide according to any one of claims 1 to 3, characterized in that: the iron content in the metatitanic acid is less than 5 ppm.

5. The method for controlling the particle size of the sulfuric acid process titanium dioxide according to any one of claims 1 to 3, characterized in that: the concentration of the slurry is 550-650 g/L.

6. The method for controlling the particle size of the titanium dioxide powder prepared by the sulfuric acid method according to any one of claims 1 to 5, characterized by comprising the following steps: the zinc salt is at least one of zinc sulfate, zinc chloride or zinc oxide.

7. The method for controlling the particle size of the titanium dioxide powder prepared by the sulfuric acid method according to any one of claims 1 to 5, characterized by comprising the following steps: the phosphate is at least one of sodium monohydrogen phosphate, sodium dihydrogen phosphate or phosphoric acid.

8. The method for controlling the particle size of the titanium dioxide powder prepared by the sulfuric acid method according to any one of claims 1 to 5, characterized by comprising the following steps: the potassium salt is at least one of potassium hydroxide, potassium chloride or potassium sulfate.

9. The method for controlling the particle size of the titanium dioxide powder prepared by the sulfuric acid method according to any one of claims 1 to 8, characterized by comprising the following steps: the calcination temperature is 870-890 ℃.

Technical Field

The invention relates to the field of chemical industry, in particular to a method for controlling particle size of titanium dioxide.

Background

Titanium dioxide (commonly known as titanium dioxide) is the best white pigment in the world at present, not only has stable physical and chemical properties, but also has excellent optical and electrical properties such as high refractive index, optimal covering power, optimal whiteness and brightness, and the like, is widely applied to the fields of coatings, plastics, papermaking, printing ink, electronics and the like, and is called as industrial monosodium glutamate.

The particle size distribution of titanium dioxide is a comprehensive index, which seriously affects the performance of titanium dioxide pigment and the application performance of products, so the discussion of covering power and dispersibility can be directly analyzed from the particle size distribution. The factors influencing the particle size distribution of the titanium dioxide are complex, firstly, the size of the primary particle size is hydrolyzed, and the primary particle size is controlled and adjusted within a certain range by controlling and adjusting the hydrolysis process conditions; secondly, the calcination temperature is adopted, the particles of the metatitanic acid undergo a crystal form conversion period and a growth period in the calcination process, and the proper temperature is controlled to ensure that the growth particles are in a certain range.

CN107500347A discloses a method for controlling the particle size of titanium dioxide of decorative base paper, which enables the titanium sulfate liquid pyrohydrolysis technology to meet the requirements of the decorative base paper, and the water and titanium dioxide have uniform particle sizes, thus meeting the specially designed hydrolysis technology required by the particle size of the titanium dioxide of the decorative base paper. The invention adjusts the particle size of titanium dioxide by the hydrolysis condition of titanyl sulfate (also called metatitanic acid).

CN106946287A discloses a method for accurately controlling the particle size of a primary titanium white product, which comprises the following steps: the method comprises three steps of titanium liquid hydrolysis, metatitanate treatment and calcination, wherein when the titanium liquid is hydrolyzed, parameters such as initial concentration, stirring speed, titanium liquid heating temperature and time and the like are adjusted, when the metatitanate is treated, the type and content of salt used are adjusted, when the metatitanate is treated, the method is divided into three sections, and the calcination temperature and time of each section are accurately controlled, so that the particle size of a primary titanium white product is accurately controlled. The method is simple to operate, the average particle size of the titanium white crude product can be effectively controlled within the range of 250-270 nm, and the obtained titanium white crude product is large in scattering power, good in optical performance and suitable for being used for general titanium white in the fields of paint and the like. The average particle size of the invention is controlled within the range of 250-270 nm, and the invention is suitable for the general field.

CN108751252A discloses a method for preparing titanium dioxide with controllable particle size, which comprises the following steps: step 1, adding ethyl cellulose into absolute ethyl alcohol, and stirring until the ethyl cellulose is completely dissolved to obtain a dispersed alcohol solution; step 2, slowly dripping n-butyl titanate into the dispersed alcohol solution, uniformly stirring, and standing at a low temperature to obtain a titanium alcohol solution; step 3, adding methyl cellulose into the titanium alcohol solution, and performing ultrasonic dispersion to form a precipitation solution; step 4, slowly dripping distilled water into the precipitation solution, uniformly stirring at a low temperature until the dripping is finished, then carrying out low-temperature ultrasonic reaction, heating the ultrasonic reaction, and keeping the temperature constant to obtain a suspension sol solution; step 5, filtering the suspension sol solution, and washing with absolute ethyl alcohol at constant temperature to obtain gel; and 6, adding the gel into an ultrasonic reaction kettle, performing circulating water bath ultrasonic reaction, cooling and filtering to obtain the nano titanium dioxide. The invention adopts ethyl cellulose as a wrapping agent to wrap the n-butyl titanate, thereby achieving the purpose of indirectly controlling the particle size of the nano titanium dioxide. The invention relates to a preparation method of nano titanium dioxide, and the size of the nano titanium dioxide is less than 100 nm.

Disclosure of Invention

The invention relates to a method for controlling the particle size of titanium dioxide by a sulfuric acid method. The method comprises the following steps: beating metatitanic acid into slurry, adding calcined seed crystal (sodium titanate containing rutile titanium dioxide crystal grains) 5.8-6.2% of titanium dioxide, 0.12-0.28% of zinc salt (zinc salt content is calculated by ZnO), and 0.27-0.53% of phosphate (phosphate content is calculated by P)₂O₅0.17-0.43% of potassium salt (the content of potassium salt is K)₂Calculated by O), the addition proportions of the calcining auxiliary agents are all based on the content of the substance oxide; then calcining until the rutile content is 98.0-99.5%. The method can be used for preparing titanium dioxide products with the average grain size of 200-250 nanometers.

Furthermore, in the method for controlling the particle size of the titanium dioxide by the sulfuric acid method, metatitanic acid (TiO) is used₂Calculated) respectively adding 6 +/-0.2 percent of calcined seed crystal, 0.15 +/-0.03 percent of zinc salt, 0.3 +/-0.03 percent of phosphate and 0.2 +/-0.03 percent of sylvite to prepare the sulfuric acid method titanium dioxide with the proportion of 210 +/-10 nanometers being more than or equal to 80 percent.

Furthermore, in the method for controlling the particle size of the titanium dioxide by the sulfuric acid method, metatitanic acid (TiO) is used₂Calculated) respectively adding 6 +/-0.2 percent of calcined seed crystal, 0.25 +/-0.03 percent of zinc salt, 0.5 +/-0.03 percent of phosphate and 0.4 +/-0.03 percent of sylvite to prepare the 240 +/-10 nanometer sulfuric acid method titanium dioxide with the proportion of more than or equal to 80 percent.

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the iron content in the metatitanic acid is less than 5 ppm.

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the concentration of the slurry is 550-650 g/L (calculated by titanium dioxide).

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the zinc salt is at least one of zinc sulfate, zinc chloride or zinc oxide.

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the phosphate is at least one of sodium monohydrogen phosphate, sodium dihydrogen phosphate or phosphoric acid.

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the potassium salt is at least one of potassium hydroxide, potassium chloride or potassium sulfate.

In the method for controlling the particle size of the titanium dioxide by the sulfuric acid process, the calcining temperature is 870-890 ℃.

The addition ratio of the above substances is metatitanic acid calculated by titanium dioxide, zinc salt calculated by ZnO, phosphate calculated by P₂O₅The amount of potassium salt added is measured by K₂And (4) measuring O.

In the process of preparing titanium dioxide by calcining metatitanic acid, the invention respectively prepares the sulfuric acid method titanium dioxide with the particle size of 210 +/-10 nanometers and the particle size of 240 +/-10 nanometers of more than or equal to 80 percent by adjusting the addition amount of the calcining auxiliary agent, and meets the requirement of the field of plastics and coatings on the particle size of the titanium dioxide.

Detailed Description

The invention relates to a preparation method of titanium dioxide with particle size of 210 +/-10 nanometers by a sulfuric acid method, which comprises the following steps: adding washing qualified metatitanic acid (the iron content is less than 5 ppm) into deionized water or distilled water, and pulping into 550-650 g/L pulp; the metatitanic acid obtained is in the form of TiO₂Meter) adding calcined seed crystal (the concentration of the seed crystal is TiO)₂g/L concentration) 6. + -. 0.2% (i.e. TiO is added)₂Calcined seed crystal 6 + -0.2% by mass, zinc chloride 0.15 + -0.03% (by TiO)₂Metering, i.e. adding TiO₂0.15 +/-0.03 percent of ZnO by mass), 0.3 +/-0.03 percent of phosphoric acid (calculated by titanium dioxide, namely 0.3 +/-0.03 percent of the mass of the added titanium dioxide), 0.2 +/-0.03 percent of potassium hydroxide (calculated by titanium dioxide, namely 0.2 +/-0.03 percent of the mass of the added titanium dioxide), and calcining at 870-890 ℃, wherein the rutile content is controlled at 98.0-99.5 percent, and the prepared sample is subjected to SEM electron microscope particle size detection. Titanium white obtained by the methodThe powder has more than 80% of particles with the particle diameter of 210 +/-10 nanometers.

The invention relates to a preparation method of titanium dioxide with particle size of 240 +/-10 nanometers by a sulfuric acid method, which comprises the following steps: adding qualified metatitanic acid (iron content is less than 5 ppm) into deionized water or distilled water, and pulping to 550-650 g/L (using TiO)₂Meter) slurry; adding calcined seed crystal 6 +/-0.2% (the concentration of the seed crystal is TiO)₂g/L concentration) and zinc chloride 0.25 + -0.03% (in terms of TiO)₂Metering, i.e. adding TiO₂0.25 +/-0.03 percent of ZnO by mass), 0.5 +/-0.03 percent of phosphoric acid (calculated by titanium dioxide, namely 0.5 +/-0.03 percent of the mass of the added titanium dioxide), 0.4 +/-0.03 percent of potassium hydroxide (calculated by titanium dioxide, namely 0.4 +/-0.03 percent of the mass of the added titanium dioxide), and calcining at 870-890 ℃, wherein the rutile content is controlled at 98.0-99.5 percent, and the prepared sample is subjected to SEM electron microscope particle size detection. The titanium dioxide obtained by the method has more than 80 percent of particles with the particle size of 240 +/-10 nanometers.

Examples

The adding proportion of the calcination seed crystal is 6.0% +/-0.2%, and other calcination auxiliary agents are as follows:

TABLE 1

As can be seen from Table 1, zinc salts, potassium salts and phosphorus salts play a key role in controlling the particle size of the calcined product. The particle size ratio statistics is carried out on 12 SEM pictures scanned by each sample, each SEM picture requires no less than 300 particle size points, and the result statistics are shown in the following tables 2 and 3:

TABLE 2

TABLE 3

As can be seen from tables 2 and 3, the reaction product in metatitanic acid (TiO)₂Calculated) respectively adding 6 +/-0.2 percent of calcined seed crystal, 0.15 +/-0.03 percent of zinc salt, 0.3 +/-0.03 percent of phosphate and 0.2 +/-0.03 percent of sylvite to prepare the sulfuric acid method titanium dioxide with the proportion of 210 +/-10 nanometers being more than or equal to 80 percent. When in metatitanic acid (as TiO)₂Calculated) respectively adding 6 +/-0.2 percent of calcined seed crystal, 0.25 +/-0.03 percent of zinc salt, 0.5 +/-0.03 percent of phosphate and 0.4 +/-0.03 percent of sylvite to prepare the 240 +/-10 nanometer sulfuric acid method titanium dioxide with the proportion of more than or equal to 80 percent.