Process for the preparation of potassium titanate whiskers and titanium dioxide whisker products

Abstract

The application relates to the field of titanate, in particular to a preparation method of potassium titanate whisker and titanium dioxide whisker products. The preparation method of the potassium titanate whisker and the titanium dioxide whisker products is synthesized by adopting a high-temperature sintering and natural slow cooling process method, and the preparation method is characterized by the following steps: S1. mixing; S2. high-temperature sintering and melting; S3. solidification and crushing; S4. dilution decomposition adjustment conversion; S5. drying; and S6. high-temperature sintering setting. The application has low cost and complete whisker.

Description

Technical Field

[0001] This invention relates to the field of titanates, specifically to a method for preparing potassium titanate whiskers and titanium dioxide whisker products. Background Technology

[0002] With the continuous deepening of research on potassium titanate whiskers, people have gained a deeper understanding and mastery of the excellent mechanical, physical and chemical properties of potassium titanate whiskers, as well as their characteristics such as high coefficient of friction, high infrared reflectivity, low thermal conductivity at high temperatures, high temperature resistance, corrosion resistance and wear resistance, which are widely used in industries such as brake pads, plastics, insulation and coatings. Although the existing "sintering-melting method" for preparing potassium titanate whiskers has irreplaceable advantages in purification technology, it still has the following major design flaws: First, the slow-cooling solidification process, which involves leaving the sintered melt in the furnace and slowly cooling it along with the furnace temperature before removing it, significantly increases the preparation time and cost of potassium titanate whiskers. Second, the rapid-cooling dispersion process, which involves placing the sintered melt in a rapid-cooling dispersion device and forcibly dispersing it into tiny powders or particles through mechanical shearing, significantly damages the material structure and morphology of the potassium titanate whiskers. Summary of the Invention

[0003] In order to overcome the shortcomings of the existing technology, and to provide a method for producing titanates that is low in production cost, simple in process technology, produces complete and uniform whiskers, and is suitable for industrial production, this invention discloses a method for preparing potassium titanate series whiskers and titanium dioxide whisker products.

[0004] The present invention achieves its objective through the following technical solution: A method for preparing potassium titanate whiskers and titanium dioxide whisker products, characterized by a high-temperature sintering and natural slow cooling process, is disclosed, comprising the following steps: S1. Mixing: Weigh the titanium source and potassium source according to the molar ratio of Ti to K of 1:1.8 to 1:2.1, and then mechanically mix them to prepare a mixed raw material; S2. High-temperature sintering and melting: The mixed raw material obtained in step S1 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually raised to 800℃~1300℃ for sintering, so that the mixed raw material is sintered into potassium dititanate melt. Then, the sintering continues for 30min~180min. The sintered potassium dititanate melt is then taken out of the heating furnace. S3. Solidification and Crushing: The potassium dititanate melt obtained in step S2 is poured into an inclined guide channel. The potassium dititanate melt flows along the guide channel to the bottom tray. After the potassium dititanate melt cools and solidifies naturally at room temperature, it forms a potassium dititanate solid sheet with a thickness of no more than 10 mm in the tray. Then, the potassium dititanate solid sheet is removed from the tray and crushed into irregular potassium dititanate fragments with a surface area of ​​no more than 5 cm × 5 cm. S4. Dilution, Decomposition, and Adjustment: First, the potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments are then subjected to sulfuric acid-free purified hot water dissolution, dilution, and decomposition treatment to prepare a purified hot water solution of potassium titanate. Next, sulfuric acid with a mass percentage concentration of 5%–40% is added to the purified hot water solution of potassium titanate to prepare a potassium titanate reaction solution. The pH value of the potassium titanate reaction solution is adjusted to 7–12, allowing the potassium titanate and sulfuric acid in the reaction solution to react for a reaction time of 1 minute. From 0 min to 480 min, by adjusting the relationship between the pH value of the reaction solution and the reaction time, a conversion method is implemented to control the amount of potassium ions dissolved from potassium dititanate, resulting in a reaction solution of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide converted from potassium dititanate. Then, the potassium dititanate reaction solution is fed into a filter for potassium removal washing and solid-liquid separation. The wet material after solid-liquid separation is discharged from the filter to obtain any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide as a wet convertible sizing agent. S5. Drying: Take out the wet convertible shaper obtained in step S4 and place it in a temperature environment of ≤70°C for simple surface drying to obtain any one of the following convertible shapers: potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide. S6. High-temperature sintering and shaping: The dried convertible sintered material obtained in step S5 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually increased to 600℃~1300℃ for shaping and sintering. The high temperature is maintained for 2 hours to 4 hours. Then, it is placed in the kiln and cooled slowly naturally with the furnace temperature, so that the convertible sintered material is sintered into a dry non-convertible crystalline sintered material. The morphology of the crystalline sintered material is any one of the following: potassium tetratitanate whiskers, potassium hexatitanate whiskers, potassium octatitanate whiskers, and titanium dioxide whiskers, with a length of 20μm~100μm and a diameter of 5μm~15μm.

[0005] The method for preparing potassium titanate whiskers and titanium dioxide whisker products is characterized in that: in step S1, TiO2 is selected as the titanium source and K2O is selected as the potassium source.

[0006] The method for preparing potassium titanate series whiskers and titanium dioxide whisker products is characterized in that: in step S2, the heating furnace is a box-type or tunnel-type kiln with a sintering temperature ≥600℃ and a duration ≥6 hours.

[0007] The method for preparing potassium titanate whiskers and titanium dioxide whisker products is characterized in that: in step S3, The base area of ​​the tray is 1.5m2 to 2m2; The potassium titanate solid flakes are crushed using a crusher or manually.

[0008] The method for preparing potassium titanate whiskers and titanium dioxide whisker products is characterized in that: in step S4, The process of dissolving, diluting, and decomposing potassium titanate fragments using sulfuric acid-free purified hot water is carried out as follows: The potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments and purified water are mixed at a mass ratio of 1:5 to 1:50. The temperature of the purified water is raised to no less than 50°C. The stirrer is started and the sulfuric acid-free purified hot water solution is stirred at a constant speed for no less than 15 minutes to fully decompose the potassium titanate fragments in the sulfuric acid-free purified water solution, forming a potassium titanate purified hot water solution. The aforementioned conversion method for controlling the potassium ion dissolution of potassium titanate involves, firstly, in the preparation of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide, a method for precisely controlling the mass ratio of sulfuric acid in the purified hot aqueous solution of potassium titanate to convert the purified hot aqueous solution of potassium titanate into a potassium titanate reaction solution. Then, the temperature of the potassium titanate reaction solution in the reaction vessel, the concentration of the sulfuric acid solution, the pH value of the reaction solution, and the reaction time are adjusted to obtain an effective method for precisely converting potassium titanate into any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide.

[0009] The method for preparing potassium titanate series whiskers and titanium dioxide whisker products is characterized in that: in step S6, the shaping sintering refers to a method of high-temperature sintering and shaping of any one of the converted potassium tetratitanate, potassium hexatitanate, potassium octatitanate and titanium dioxide after drying, in order to fix the position of potassium ions in the shaped material and ablate the potassium ions that overflow from the shaped material.

[0010] The method for preparing potassium titanate whiskers and titanium dioxide whisker products is characterized by: In step S3, the potassium disitianate melt is taken out from the high-temperature furnace and poured into the centrifugal disc of the centrifugal curing machine through the guide pipe. The centrifugal curing machine is started, and the potassium disitianate melt is centrifugally thrown onto the inner wall of the centrifugal curing machine under the action of centrifugal force, forming a potassium disitianate solid film with a thickness of 1.5 mm to 3 mm. After the potassium disitianate solid film cools and solidifies naturally, it falls off the inner wall of the machine to become the finished potassium disitianate solid sheet.

[0011] This invention overcomes the defects of existing potassium titanate whisker sintering and melting processes, avoids the drawbacks of traditional slow cooling and solidification melt processes that require destruction of the container, reduces manufacturing costs, and produces whiskers with complete and uniform structure and morphology, making it suitable for large-scale industrial production. Detailed Implementation

[0012] The present invention will be further illustrated below through specific embodiments. Example

[0013] A method for preparing potassium titanate whiskers and titanium dioxide whisker products involves a high-temperature sintering and natural slow cooling process. Specifically, the method is implemented in the following steps: S1. Mixing: Weigh the titanium source and potassium source according to the molar ratio of Ti to K of 1:1.8 to 1:2.1, and then mechanically mix them to prepare a mixed raw material; the titanium source is TiO2 and the potassium source is K2O. S2. High-temperature sintering and melting: The mixed raw material obtained in step S1 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually increased to 800℃~1300℃ for sintering, so that the mixed raw material is sintered into potassium distitanate melt. Then, the sintering is continued for 30min~180min. The sintered potassium distitanate melt is then taken out of the heating furnace. The heating furnace is a box-type or tunnel-type kiln with a sintering temperature ≥600℃ and a duration ≥6 hours. S3. Solidification and Crushing: The potassium dititanate melt obtained in step S2 is poured into an inclined guide channel. The potassium dititanate melt flows along the guide channel to the bottom tray. After the potassium dititanate melt cools and solidifies naturally at room temperature, it forms a potassium dititanate solid sheet with a thickness of no more than 10 mm in the tray. Then, the potassium dititanate solid sheet is removed from the tray and crushed into irregular potassium dititanate fragments with a surface area of ​​no more than 5 cm × 5 cm. The base area of ​​the tray is 1.5m2 to 2m2; When crushing the potassium titanate solid flakes, a crusher or manual operation can be used. S4. Dilution, Decomposition, and Adjustment: First, the potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments are then subjected to sulfuric acid-free purified hot water dissolution, dilution, and decomposition treatment to prepare a purified hot water solution of potassium titanate. Next, sulfuric acid with a mass percentage concentration of 5%–40% is added to the purified hot water solution of potassium titanate to prepare a potassium titanate reaction solution. The pH value of the potassium titanate reaction solution is adjusted to 7–12, allowing the potassium titanate and sulfuric acid in the reaction solution to react for a reaction time of 1 minute. From 0 min to 480 min, by adjusting the relationship between the pH value of the reaction solution and the reaction time, a conversion method is implemented to control the amount of potassium ions dissolved from potassium dititanate, resulting in a reaction solution of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide converted from potassium dititanate. Then, the potassium dititanate reaction solution is fed into a filter for potassium removal washing and solid-liquid separation. The wet material after solid-liquid separation is discharged from the filter to obtain any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide as a wet convertible sizing agent. The process of dissolving, diluting, and decomposing potassium titanate fragments using sulfuric acid-free purified hot water is carried out as follows: The potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments and purified water are mixed at a mass ratio of 1:5 to 1:50. The temperature of the purified water is raised to no less than 50°C. The stirrer is started and the sulfuric acid-free purified hot water solution is stirred at a constant speed for no less than 15 minutes to fully decompose the potassium titanate fragments in the sulfuric acid-free purified water solution, forming a potassium titanate purified hot water solution. The aforementioned conversion method for controlling the potassium ion dissolution of potassium titanate first involves precisely controlling the sulfuric acid mass ratio in the preparation of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide, specifically targeting the purified hot aqueous solution of potassium titanate. This converts the purified hot aqueous solution of potassium titanate into a potassium titanate reaction solution. Then, the temperature of the potassium titanate reaction solution in the reaction vessel, the concentration of the sulfuric acid solution, the pH value of the reaction solution, and the reaction time are adjusted to obtain an effective method for precisely converting potassium titanate into any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide. S5. Drying: Take out the wet convertible shaper obtained in step S4 and place it in a temperature environment of ≤70°C for simple surface drying to obtain any one of the following convertible shapers: potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide. S6. High-temperature sintering and shaping: The dried convertible shaped material obtained in step S5 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually increased to 600℃~1300℃ for shaping and sintering. The high temperature is maintained for 2 hours to 4 hours. Then, it is placed in the kiln and cooled slowly naturally with the furnace temperature, so that the convertible shaped material is sintered into a dry non-convertible crystalline shaped material. The morphology of the crystalline shaped material is any one of the following: potassium tetratitanate whiskers, potassium hexatitanate whiskers, potassium octatitanate whiskers, and titanium dioxide whiskers, with a length of 20μm~100μm and a diameter of 5μm~15μm. The aforementioned shaping sintering refers to a method of high-temperature sintering and shaping a dried convertible material that has been converted into any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide under high-temperature conditions, in order to fix the position of potassium ions in the material and ablate the potassium ions that overflow from the material. Example

[0014] A method for preparing potassium titanate whiskers and titanium dioxide whisker products involves a high-temperature sintering and natural slow cooling process. Specifically, the method is implemented in the following steps: S1. Mixing: Same as step S1 in Example 1; S2. High-temperature sintering and melting: Same as step S2 in Example 1; S3. Solidification and Crushing: The potassium dititanate melt is taken out from the high-temperature furnace and poured into the centrifugal disc of the centrifugal solidification machine through the guide pipe. The centrifugal solidification machine is started, and the potassium dititanate melt is centrifugally thrown onto the inner wall of the centrifugal solidification machine under the action of centrifugal force, forming a potassium dititanate solid film with a thickness of 1.5mm to 3mm. After the potassium dititanate solid film cools and solidifies naturally, it falls off the inner wall of the machine to become the finished potassium dititanate solid sheet. S4. Dilution, decomposition, and adjustment conversion: Same as step S4 in Example 1; S5. Drying: Same as step S5 in Example 1; S6. High-temperature sintering and shaping: Same as step S6 in Example 1.

Claims

1. A method for preparing potassium titanate whiskers and titanium dioxide whisker products, characterized by a high-temperature sintering and natural slow cooling process: Follow these steps in sequence: S1. Mixing: Weigh the titanium source and potassium source according to the molar ratio of Ti to K of 1:1.8 to 1:2.1, and then mechanically mix them to prepare a mixed raw material; S2. High-temperature sintering and melting: The mixed raw material obtained in step S1 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually raised to 800℃~1300℃ for sintering, so that the mixed raw material is sintered into potassium dititanate melt. Then, the sintering continues for 30min~180min. The sintered potassium dititanate melt is then taken out of the heating furnace. S3. Solidification and Crushing: The potassium dititanate melt obtained in step S2 is poured into an inclined guide channel. The potassium dititanate melt flows along the guide channel to the bottom tray. After the potassium dititanate melt cools and solidifies naturally at room temperature, it forms a potassium dititanate solid sheet with a thickness of no more than 10 mm in the tray. Then, the potassium dititanate solid sheet is removed from the tray and crushed into irregular potassium dititanate fragments with a surface area of ​​no more than 5 cm × 5 cm. S4. Dilution, Decomposition, and Adjustment: First, the potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments are then subjected to sulfuric acid-free purified hot water dissolution, dilution, and decomposition treatment to prepare a purified hot water solution of potassium titanate. Next, sulfuric acid with a mass percentage concentration of 5%–40% is added to the purified hot water solution of potassium titanate to prepare a potassium titanate reaction solution. The pH value of the potassium titanate reaction solution is adjusted to 7–12, allowing the potassium titanate and sulfuric acid in the reaction solution to react for a reaction time of 1 minute. From 0 min to 480 min, by adjusting the relationship between the pH value of the reaction solution and the reaction time, a conversion method is implemented to control the amount of potassium ions dissolved from potassium dititanate, resulting in a reaction solution of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide converted from potassium dititanate. Then, the potassium dititanate reaction solution is fed into a filter for potassium removal washing and solid-liquid separation. The wet material after solid-liquid separation is discharged from the filter to obtain any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide as a wet convertible sizing agent. S5. Drying: Take out the wet convertible shaper obtained in step S4 and place it in a temperature environment of ≤70°C for simple surface drying to obtain any one of the following convertible shapers: potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide. S6. High-temperature sintering and shaping: The dried convertible sintered material obtained in step S5 is placed in a crucible container and placed in a heating furnace with a temperature ≤50℃. The temperature is gradually increased to 600℃~1150℃ for shaping and sintering. The high temperature is maintained for 2 hours to 4 hours. Then, it is placed in the kiln and cooled slowly naturally with the furnace temperature, so that the convertible sintered material is sintered into a dry non-convertible crystalline sintered material. The morphology of the crystalline sintered material is any one of the following: potassium tetratitanate whiskers, potassium hexatitanate whiskers, potassium octatitanate whiskers, and titanium dioxide whiskers, with a length of 20μm~100μm and a diameter of 5μm~15μm.

2. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in claim 1, characterized in that: In step S1, TiO2 is selected as the titanium source and K2O is selected as the potassium source.

3. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in claim 2, characterized in that: In step S2, the heating furnace is selected as a box-type or tunnel-type kiln with a sintering temperature ≥600℃ and a duration ≥6 hours.

4. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in claim 3, characterized in that: In step S3, The bottom area of ​​the tray is 1.5m2 to 2m2; The potassium titanate solid flakes are crushed using a crusher or manually.

5. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in claim 4, characterized in that: In step S4, The process of dissolving, diluting, and decomposing potassium titanate fragments using sulfuric acid-free purified hot water is carried out as follows: The potassium titanate fragments obtained in step S3 are placed in a reactor containing purified water. The potassium titanate fragments and purified water are mixed at a mass ratio of 1:5 to 1:

50. The temperature of the purified water is raised to no less than 50°C. The stirrer is started and the sulfuric acid-free purified hot water solution is stirred at a constant speed for no less than 15 minutes to fully decompose the potassium titanate fragments in the sulfuric acid-free purified water solution, forming a potassium titanate purified hot water solution. The aforementioned conversion method for controlling the potassium ion dissolution of potassium titanate involves, firstly, in the preparation of any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide, a method for precisely controlling the mass ratio of sulfuric acid in the purified hot aqueous solution of potassium titanate to convert the purified hot aqueous solution of potassium titanate into a potassium titanate reaction solution. Then, the temperature of the potassium titanate reaction solution in the reaction vessel, the concentration of the sulfuric acid solution, the pH value of the reaction solution, and the reaction time are adjusted to obtain an effective method for precisely converting potassium titanate into any one of potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide.

6. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in claim 5, characterized in that: In step S6, the shaping sintering refers to a method of high-temperature sintering and shaping of any one of the converted potassium tetratitanate, potassium hexatitanate, potassium octatitanate, and titanium dioxide under high-temperature conditions, so as to fix the position of potassium ions in the shaped material and ablate the potassium ions that overflow from the shaped material.

7. The method for preparing potassium titanate whiskers and titanium dioxide whisker products as described in any one of claims 1 to 6, characterized in that: In step S3, the potassium disitianate melt is taken out from the high-temperature furnace and poured into the centrifugal disc of the centrifugal curing machine through the guide pipe. The centrifugal curing machine is started, and the potassium disitianate melt is centrifugally thrown onto the inner wall of the centrifugal curing machine under the action of centrifugal force, forming a potassium disitianate solid film with a thickness of 1.5 mm to 3 mm. After the potassium disitianate solid film cools and solidifies naturally, it falls off the inner wall of the machine to become the finished potassium disitianate solid sheet.