A post-treatment process for electronic grade high-purity titanium dioxide slurry

Abstract

A post-treatment process for electronic grade high-purity titanium dioxide slurry comprises beating electronic grade high-purity titanium dioxide semi-finished product with a purity of more than 99.9% to obtain electronic grade high-purity titanium dioxide slurry, adding 0.2% to 0.3% of the mass of titanium dioxide polycarboxylic acid ammonium salt dispersant or polyacrylic acid ammonium salt dispersant, stirring for 10 to 20 minutes, adjusting the pH value to 6.5 to 7.5 with 20% to 30% alkali solution, stirring for 10 to 20 minutes, filtering, drying, and adding 0.2% to 0.5% of isostearic acid in the gas powder. This post-treatment process can effectively reduce the viscosity of electronic grade high-purity titanium dioxide slurry, realize uniform dispersion and pipeline transportation of the slurry, and significantly improve the wall adhesion and agglomeration of materials during drying, thereby realizing the industrialized continuous production of electronic grade high-purity titanium dioxide.

Description

Technical Field

[0001] The invention relates to a post-treatment process for electronic-grade high-purity titanium dioxide slurry. Background Art

[0002] Electronic-grade high-purity titanium dioxide can be used in solid-phase synthesis of dielectric materials such as multilayer ceramic capacitors (MLCCs), as well as basic raw materials for electronic components such as DCCs and positive temperature coefficient thermistors (PTCs) due to its semiconductor properties, high dielectric constant and conductivity.

[0003] At present, the production of electronic grade high-purity titanium dioxide mainly includes sulfuric acid method, hydrolysis method and chlorination method. The sulfuric acid method is simple and mature, with easy-to-obtain raw materials, low cost and simple equipment; but the process is long, with many "three wastes" and high energy consumption. The hydrolysis method has a short process flow and good product quality; but the raw materials require high quality and the production cost is high. The chlorination method has a short process flow, a high degree of automation, and less "three wastes", but the impurity content of the chlorination method is difficult to control. In order to reduce the introduction of impurities, the crystal conversion agent AlCl3 is not added in the gas phase oxidation stage for production. The pH value of this type of titanium dioxide semi-product is between 1 and 2, the isoelectric point is generally between pH 4 and 5, and the initial viscosity of its water slurry is low, generally below 100cP. Because the titanium dioxide used in electronic components is in the process of composite powder processing, the pH value of titanium dioxide is required to be near neutral, generally requiring a pH value of 6.5 to 7.5. When the pH value of the water slurry is adjusted from acidic to 6.5-7.5, because no inorganic agents such as AlCl3 are added during production and the pH value is adjusted across the isoelectric point, the viscosity of the 25%-30% concentration water slurry is as high as 3900cP-4600cP, which cannot achieve uniform dispersion and pipeline transportation of the post-process water slurry. If the slurry is transported first and then the pH value is adjusted, the acidic slurry will cause a certain degree of corrosion to the post-processing equipment and pipelines, and there will be a problem of wall adhesion.

[0004] According to the industry standard for electronic grade titanium dioxide, the content of TiO2 in titanium dioxide is ≥99.0%, the content of SiO2 is ≤0.20%, the content of potassium and sodium (calculated as K2O+Na2O) is ≤0.20%, the content of calcium and magnesium (calculated as CaO+MgO) is ≤0.20%, and the content of Fe2O3 is ≤0.03%, etc. Therefore, electronic grade high purity titanium dioxide needs to solve the problems of titanium dioxide slurry viscosity, slurry thixotropy, and wall adhesion during drying, gas powder and pipeline transportation without introducing impurity elements. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a post-treatment process for electronic grade high-purity titanium dioxide slurry which can effectively reduce the viscosity of the slurry during pH adjustment, solve the problem of slurry sticking to the wall during pipeline transportation in production and improve the thixotropy of the slurry; add an organic treatment agent during gas powder to solve the problem of material easy sticking to the wall and agglomeration, and do not introduce impurity elements, thereby ensuring the purity of titanium dioxide and reducing production costs.

[0006] The technical solution of the present invention is as follows:

[0007] A post-treatment process for electronic grade high-purity titanium dioxide slurry, characterized by:

[0008] The following steps are involved:

[0009] 1) adding the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain an electronic grade high purity titanium dioxide slurry, adding a dispersant to the electronic grade high purity titanium dioxide slurry, wherein the dispersant is a polycarboxylate ammonium salt dispersant or a polyacrylic acid ammonium salt dispersant, and stirring at room temperature for 10 min to 20 min;

[0010] 2) Adjust the pH value to 6.5-7.5 with 20%-30% alkali solution and stir for 10-20 minutes;

[0011] 3) After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid are added into a gas powder machine. The isostearic acid is added by atomizing with an atomizing spray gun. After gas powder treatment, an electronic grade high-purity titanium dioxide product is obtained.

[0012] Further preferably, in step 1), the molecular weight of the polycarboxylate ammonium salt dispersant or the polyacrylic acid ammonium salt dispersant is 5000-8000, and the amount of the dispersant added accounts for 0.2%-0.3% of the mass of the titanium dioxide semi-finished product.

[0013] Further preferably, in step 3), the isostearic acid accounts for 0.2% to 0.5% by weight of the titanium dioxide semi-finished product.

[0014] Further preferably, in step 1), the mass concentration of the electronic grade high purity titanium dioxide slurry is 25% to 30%.

[0015] Further preferably, in step 1), the raw material of the electronic grade high-purity titanium dioxide slurry is a semi-finished titanium dioxide powder prepared by a gas phase oxidation method, and the purity of the semi-finished titanium dioxide powder after washing with deionized water is ≥99.9%.

[0016] Further preferably, in step 1) and step 2), the average shear rate during stirring is controlled at 220s -1 ~260s -1 .

[0017] Further preferably, in step 2), the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution.

[0018] Further preferably, in step 3), the gas-powder steam temperature is 260-280°C.

[0019] Further preferably, when the semi-finished titanium dioxide powder is prepared by the gas phase oxidation method, liquid refined titanium tetrachloride is added to the hot oxygen gas flow that has been preheated for the second time, the liquid refined titanium tetrachloride is pressurized by the feed pump and transported to the spray gun, and is sprayed into the hot oxygen gas flow after being atomized, and the titanium dioxide produced by the reaction of the atomized titanium tetrachloride and the hot oxygen gas flow enters the reaction zone of the high-temperature oxidation reactor with the hot oxygen gas flow; the hot oxygen gas flow containing a small amount of reaction product titanium dioxide is mixed and reacted with the refined titanium tetrachloride in the reaction zone of the high-temperature oxidation reactor with an inner diameter of 130 mm, and potassium chloride, a grain refiner, is added to the reaction zone; the titanium dioxide and by-product gas phase suspension generated in the reaction zone are cooled by a water bath conduit with an inner diameter of 150 mm at the outlet pipe of the high-temperature oxidation reactor, and the temperature at the conduit 50 m downstream of the high-temperature oxidation reactor is controlled to be 700° C. by the amount of rock salt added, and the cooled gas phase suspension is subjected to gas-solid separation, and the solid matter is the semi-finished titanium dioxide powder.

[0020] Further preferably, the added amount of the grain refiner potassium chloride accounts for 100 ppm of the total mass of titanium tetrachloride.

[0021] The beneficial effects of the present invention are:

[0022] The present invention uses a titanium dioxide semi-finished product prepared without adding AlCl3 as a crystal conversion agent as a titanium dioxide water slurry raw material, and uses a low molecular weight polymer polycarboxylic acid ammonium salt dispersant or polyacrylate ammonium salt dispersant to disperse the water slurry without introducing impurity elements (such as Na2O, SiO2, Al2O3, etc.), thereby solving the problem of material wall adhesion during drying and improving the thixotropy of the slurry. If no organic treatment agent is added, the material wall adhesion will cause the system and the conveying pipeline to be blocked, and the system needs to be cleaned before production. Therefore, the atomized organic treatment agent isostearic acid is used during gas powder to solve the problem of easy material wall adhesion and agglomeration; thereby achieving long-term industrial production. DETAILED DESCRIPTION

[0023] The titanium dioxide slurry of the present invention is a titanium dioxide semi-finished powder prepared by a gas phase oxidation method without adding AlCl3 as a crystal conversion agent. It can be an electronic grade high-purity titanium dioxide semi-finished product with a purity of more than 99.9% after washing with deionized water. The purity of the electronic grade high-purity titanium dioxide used in Examples 1-3 and Comparative Examples 1-5 of the present invention is 99.97% (after washing with deionized water). The specific production process is as follows:

[0024] (1) Preheating refined titanium tetrachloride to 480° C. through a titanium tetrachloride preheater, and preheating oxygen to 870° C. through an oxygen preheater, and introducing them into a high-temperature oxidation reactor respectively;

[0025] (2) preheating the preheated oxygen to 1650° C. in a high-temperature oxidation reactor using the heat generated by the combustion of toluene; adding 50 kg / h of liquid refined titanium tetrachloride to a hot oxygen gas flow at a temperature of 1650° C. and a flow rate of 1000 kg / h at a position 700 mm away from the reaction zone of the high-temperature oxidation reactor under a system pressure of 350 kPa, the liquid refined titanium tetrachloride is pressurized by a feed pump and transported to a spray gun, and is sprayed into the hot oxygen gas flow after being atomized. The feed pump pressure is 200 to 400 kPa higher than the system pressure. In this embodiment, the feed pump pressure is 200 kPa higher than the system pressure. The atomized titanium tetrachloride reacts with the hot oxygen gas flow to produce titanium dioxide, which enters the reaction zone of the high-temperature oxidation reactor along with the hot oxygen gas flow;

[0026] (3) a hot oxygen gas stream containing a small amount of titanium dioxide as a reaction product is mixed with refined titanium tetrachloride at a flow rate of 5000 kg / h and a temperature of 480° C. in a reaction zone of a high-temperature oxidation reactor having an inner diameter of 130 mm, and potassium chloride as a grain refiner is added to the reaction zone in an amount of 100 ppm relative to the mass of titanium tetrachloride; the potassium chloride is added in the form of an aqueous solution with a concentration of 200 g / L;

[0027] (4) The titanium dioxide and by-product gaseous suspension generated in the reaction zone are cooled by a water bath conduit with an inner diameter of 150 mm at the outlet pipe of the high-temperature oxidation reactor, and the temperature at the conduit 50 m downstream of the high-temperature oxidation reactor is controlled to be 700° C. by adding rock salt. The cooled gaseous suspension is subjected to gas-solid separation, and the solid matter is the electronic grade high-purity titanium dioxide semi-finished product.

[0028] Example 1

[0029] 1. Add the semi-finished electronic grade high-purity titanium dioxide to deionized water to obtain a 25% electronic grade high-purity titanium dioxide slurry. Add a polycarboxylate ammonium salt dispersant with a molecular weight of 5000 and a mass concentration of 0.2% of the titanium dioxide to the electronic grade high-purity titanium dioxide slurry. -1 Stir for 10 min under the same conditions;

[0030] 2. Use 20% sodium hydroxide solution to adjust the pH to 6.5, and control the average shear rate at 220s. -1 Stir for 10 min under the same conditions;

[0031] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.2% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 260°C, and gas powder treatment is performed to obtain electronic grade high-purity titanium dioxide products.

[0032] Example 2

[0033] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 30% electronic grade high purity titanium dioxide slurry, add a polyacrylic acid ammonium salt dispersant with a molecular weight of 8000 and a mass concentration of 0.3% of the titanium dioxide to the electronic grade high purity titanium dioxide slurry, and control the average shear rate at 260s -1 Stir for 20 min under the same conditions;

[0034] 2. Use 30% potassium hydroxide solution to adjust the pH to 7.5, and control the average shear rate at 260s. -1 Stir for 20 min under the same conditions;

[0035] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.5% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 280°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0036] Example 3

[0037] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry, add a polycarboxylate ammonium salt dispersant with a molecular weight of 5000 and a concentration of 0.26% of the mass of titanium dioxide to the electronic grade high purity titanium dioxide slurry, and control the average shear rate at 240s -1 Stir for 15 min under the same conditions;

[0038] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0039] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.4% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 270°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0040] Comparative Example 1

[0041] Comparative Example 1, without using a dispersant, the steps are as follows:

[0042] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry at an average shear rate of 240s. -1 Stir for 15 min under the same conditions;

[0043] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0044] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.4% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 270°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0045] Comparative Example 2

[0046] Comparative Example 2: The dispersant used was 0.3% citric acid by mass of titanium dioxide, and the steps were as follows:

[0047] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry, add 0.3% citric acid to the electronic grade high purity titanium dioxide slurry, and control the average shear rate at 240s -1 Stir for 15 min under the same conditions;

[0048] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0049] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.4% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 270°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0050] Comparative Example 3

[0051] Comparative Example 3, isostearic acid is not added during the gas powder, and the steps are as follows:

[0052] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry, add 0.26% of the mass of titanium dioxide to the electronic grade high purity titanium dioxide slurry, the molecular weight of the polycarboxylate ammonium salt dispersant is 5000, and the average shear rate is controlled at 240s -1 Stir for 15 min under the same conditions;

[0053] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0054] 3. After filtering, washing and drying, the obtained titanium dioxide powder is added to the gas powder machine. The steam temperature in the gas powder machine is controlled at 270°C for gas powder treatment to obtain electronic grade high-purity titanium dioxide products.

[0055] Comparative Example 4

[0056] Comparative Example 4, using a dispersant with a lower molecular weight, the steps are as follows:

[0057] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry, add a polycarboxylate ammonium salt dispersant with a molecular weight of 3000 and a concentration of 0.26% of the mass of titanium dioxide to the electronic grade high purity titanium dioxide slurry, and control the average shear rate at 240s -1 Stir for 15 min under the same conditions;

[0058] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0059] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.4% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 270°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0060] Comparative Example 5

[0061] Comparative Example 5, using a dispersant with a higher molecular weight, the steps are as follows:

[0062] 1. Add the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain a 27% electronic grade high purity titanium dioxide slurry, add a polycarboxylate ammonium salt dispersant with a molecular weight of 10000 and a concentration of 0.26% of the mass of titanium dioxide to the electronic grade high purity titanium dioxide slurry, and control the average shear rate at 240s -1 Stir for 15 min under the same conditions;

[0063] 2. Use 26% sodium hydroxide solution to adjust the pH to 6.9, and control the average shear rate at 240s. -1 Stir for 15 min under the same conditions;

[0064] 3. After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid atomized by an atomizing spray gun are added into a gas powder machine, wherein the amount of isostearic acid added accounts for 0.4% of the mass of titanium dioxide. The steam temperature in the gas powder machine is controlled at 270°C, and gas powder treatment is carried out to obtain electronic grade high-purity titanium dioxide products.

[0065] The post-processing process monitoring data of the examples and comparative examples are shown in Table 1, and the product analysis indicators are shown in Table 2.

[0066] Table 1 Post-treatment process monitoring data of the products of the embodiments and comparative examples

[0067]

[0068] Table 2 Analysis indicators of the products of the embodiments and comparative examples

[0069]

[0070] The polycarboxylate ammonium salt dispersant or polyacrylate ammonium salt dispersant used in the present invention has an ionic property and a steric hindrance effect that are superior to conventional organic dispersants. The surface hydroxyl groups of titanium dioxide form a chemical bond with the polycarboxylate ammonium salt dispersant or polyacrylate ammonium salt dispersant, and the chemical bond enables the polycarboxylate ammonium salt dispersant or polyacrylate ammonium salt dispersant molecules to form an adsorption layer on the surface of titanium dioxide particles. In a high-purity titanium dioxide slurry, an appropriate amount of polycarboxylate ammonium salt dispersant or polyacrylate ammonium salt dispersant is added, and its molecules will be adsorbed on the surface of titanium dioxide particles in a ring-shaped or tail-shaped manner, forming a polymer layer of sufficient thickness on the surface of titanium dioxide particles, thereby effectively preventing the titanium dioxide particles from contacting each other, and then effectively reducing the viscosity of the high-purity titanium dioxide slurry.

[0071] From the data in Table 1 and related experiments, it can be seen that if citric acid is used as a dispersant, when the amount added is small, the slurry viscosity cannot be reduced; when the amount added can reduce the viscosity of the water slurry, when the pH is adjusted to 6.5-7.5, the titanium dioxide particles exist in the form of primary particles, and the titanium dioxide will pass through the filter cloth during filtration, and the product thixotropy is poor and cannot form a filter cake. In addition, the present invention also uses organic treatment agents or polymers such as lauric acid polyoxyethylene ester, anhydride copolymer, polyethylene glycol, and octanoic acid polyglycerol ester as dispersants, among which only the anhydride copolymer has a slight improvement in reducing viscosity, and other organic treatment agents have no effect of reducing viscosity during the pH adjustment process, but the anhydride copolymer has a poor product thixotropy during filtration and cannot form a filter cake, thereby failing to achieve industrial production. Comparative Example 4 uses a dispersant with a lower molecular weight. According to the amount added in the present invention, the viscosity of the high-purity titanium dioxide water slurry cannot be effectively reduced. Comparative Example 5 uses a dispersant with a higher molecular weight, and the flocculation ability of the high-purity titanium dioxide water slurry is enhanced, the viscosity increases, and the viscosity reduction effect is weakened.

[0072] As can be seen from the data in Table 2, the type and amount of organic treatment agent have no significant effect on the main content and impurity element content of the product, but have a greater impact on fluidity. This is because the material particles crushed by air flow become finer, the particle surface layer is subjected to mechanical damage and micro-plastic deformation, the material is partially or completely converted into a metastable amorphous state, and the surface activity and the attraction of the particle surface: such as van der Waals force, electrostatic force and hydrogen bond force increase, which easily leads to recombination and reunion between particles, thereby causing wall adhesion. Isostearic acid is used in the present invention to solve the wall adhesion problem in the post-processing process. It is adsorbed or chemically combined on the active points on the surface of titanium dioxide particles to form a firm coating layer, which not only effectively reduces the particle surface activity, but also balances the unsaturated valence bonds on the particle surface, eliminates the static electricity generated by material friction during the pulverization process, reduces wall adhesion and reunion, and improves the fluidity of titanium dioxide. In addition, when the organic treatment agent used in the present invention is applied to electronic materials, its processing technology will undergo calcination at 1000°C to 1300°C. At this temperature, all the organic treatment agents are volatilized, which can fully ensure the application performance of electronic component products.

[0073] The above are only specific embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A post-treatment process for electronic grade high-purity titanium dioxide slurry, characterized in that: The following steps are involved: 1) adding the electronic grade high purity titanium dioxide semi-finished product to deionized water to obtain an electronic grade high purity titanium dioxide slurry, adding a dispersant to the electronic grade high purity titanium dioxide slurry, wherein the dispersant is a polycarboxylate ammonium salt dispersant, and the molecular weight of the polycarboxylate ammonium salt dispersant is 5000 to 8000, and stirring at room temperature for 10 min to 20 min; 2) Adjust the pH value to 6.5-7.5 with 20%-30% alkali solution and stir for 10-20 minutes; 3) After filtering, washing and drying, the obtained titanium dioxide powder and isostearic acid are added to the gas powder machine. The isostearic acid is added by atomizing spray gun. After gas powder treatment, electronic grade high-purity titanium dioxide products are obtained; In step 1), the raw material of the electronic grade high-purity titanium dioxide slurry is a semi-finished titanium dioxide powder prepared by a gas phase oxidation method, and the semi-finished titanium dioxide powder is washed with deionized water to obtain an electronic grade high-purity titanium dioxide semi-finished product with a titanium dioxide purity of ≥99.9%; When preparing titanium dioxide semi-finished product powder by gas phase oxidation method, liquid refined titanium tetrachloride is added to the hot oxygen gas flow which has been preheated twice, the liquid refined titanium tetrachloride is pressurized by a feed pump and then transported to a spray gun, and then sprayed into the hot oxygen gas flow after being atomized, and the titanium dioxide produced by the reaction of the atomized titanium tetrachloride and the hot oxygen gas flow enters the reaction zone of the high-temperature oxidation reactor along with the hot oxygen gas flow; the hot oxygen gas flow containing a small amount of titanium dioxide produced by the reaction is mixed and reacted with refined titanium tetrachloride in the reaction zone of the high-temperature oxidation reactor with an inner diameter of 130 mm, and potassium chloride, a grain refiner, is added to the reaction zone at the same time; the titanium dioxide and by-product gas phase suspension produced in the reaction zone are cooled through a water bath conduit with an inner diameter of 150 mm at the outlet pipe of the high-temperature oxidation reactor, and the temperature at the conduit 50 m downstream of the high-temperature oxidation reactor is controlled to be 700° C. by the amount of rock salt added, and the gas phase suspension after cooling is subjected to gas-solid separation, and the solid matter is the titanium dioxide semi-finished product powder.

2. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1, characterized in that: In step 1), the amount of dispersant added is 0.2% to 0.3% of the mass of the titanium dioxide semi-finished product.

3. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1 is characterized in that: In step 3), the isostearic acid accounts for 0.2% to 0.5% of the mass of the titanium dioxide semi-finished product.

4. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1 is characterized in that: In step 1), the mass concentration of electronic grade high purity titanium dioxide slurry is 25% to 30%.

5. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1 is characterized in that: The polycarboxylate ammonium salt dispersant is a polyacrylic acid ammonium salt dispersant.

6. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1, characterized in that: In step 1) and step 2), the average shear rate during stirring was controlled at 220 s -1 ~260s -1 .

7. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1, characterized in that: In step 2), the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution.

8. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1, characterized in that: In step 3), the gas-powder steam temperature is 260-280°C.

9. The post-treatment process of electronic grade high-purity titanium dioxide slurry according to claim 1, characterized in that: The amount of potassium chloride added as a grain refiner accounts for 100 ppm of the total mass of titanium tetrachloride.

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