Metatitanic acid slurry and method for its production and rutile titanium dioxide and method for its production

Abstract

The present application relates to the technical field of pigment preparation, and particularly relates to metatitanic acid slurry, a preparation method thereof and rutile titanium dioxide and a preparation method thereof. The preparation method of the titanium dioxide comprises the following steps: mixing an imidazole ionic liquid and a first titanium oxychloride solution to perform heating treatment to form crystal seeds, then under the condition of reduced pressure distillation, a second titanium oxychloride solution is added, the evaporation amount is adjusted to maintain the volume of the system unchanged, the crystal seeds are allowed to grow, and then drying and calcination are performed; wherein the first titanium oxychloride solution and the second titanium oxychloride solution are both prepared by hydrochloric acid extraction method. The preparation method can prepare the rutile titanium dioxide with long strip shape and good pigment performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pigment preparation, in particular to metatitanic acid slurry and its preparation method and rutile titanium dioxide and its preparation method. BACKGROUND

[0002] Titanium dioxide, also known as titanium white, is a kind of white powder with soft texture, no smell and no taste. It has strong hiding power and coloring power, so it is often used as dye and pigment. Among them, titanium dioxide can be divided into anatase titanium white and rutile titanium white according to its crystal form. However, the shape of titanium white is basically round or oval, which limits its application. At the same time, the shape of titanium white prepared by the existing preparation method is not easy to control, and the size is different, which further limits its application.

[0003] For example, the existing technology of preparing titanium white by sulfuric acid method adopts acidolysis, hydrolysis, impurity removal, salt treatment, calcination and wet grinding, and then sand grinding, coating and air powdering. Or CN201811391296.9: Preparation method of pigment titanium dioxide is described as follows: a. Water is added to metatitanic acid with iron content less than 30ppm to obtain slurry 1 with titanium dioxide concentration of 200 450g / L; b. Add organic modifier to slurry 1, then add treatment agent and stir to obtain slurry 2; c. The slurry 2 is pressed into metatitanic acid filter cake, and then calcined to obtain titanium dioxide primary product. The titanium white prepared by the above method is round or oval, and the size of the titanium white is different.

[0004] Therefore, the present application is proposed. SUMMARY

[0005] The present application provides a metatitanic acid slurry and its preparation method and rutile titanium dioxide and its preparation method. The preparation method provided by the present application can prepare long strip-shaped rutile titanium dioxide, expand the application range of titanium dioxide, and control the aspect ratio of the preparation, which is beneficial to ensure the uniformity of the shape and size of the formed rutile titanium dioxide.

[0006] The present application is realized as follows:

[0007] In a first aspect, the present application provides a preparation method of metatitanic acid slurry, comprising: mixing imidazole ionic liquid and first titanium oxychloride solution for heating treatment to form crystal seeds, and then adding second titanium oxychloride solution under reduced pressure distillation conditions, adjusting the evaporation amount to maintain the volume of the system unchanged, so that the crystal seeds grow; wherein the first titanium oxychloride solution and the second titanium oxychloride solution are both prepared by hydrochloric acid extraction method.

[0008] In an alternative embodiment, the imidazolium ionic liquid is selected from the group consisting of 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate.

[0009] In an alternative embodiment, the concentration of the first and second titanium oxychloride solutions comprises 80-250 g / L, preferably 160-250 g / L.

[0010] In an alternative embodiment, the heating treatment comprises heating to 70-90 °C and maintaining for 15-30 minutes, and then cooling to 50-60 °C.

[0011] In an alternative embodiment, the method comprises mixing the imidazolium ionic liquid, the first titanium oxychloride solution and soft water, heating to 70-90 °C and maintaining for 15-30 minutes, and then cooling to 50-60 °C, and then adding the second titanium oxychloride solution under a vacuum degree of -0.08 to -0.9 MPa, adjusting the evaporation amount to maintain the volume of the system unchanged until the reaction is completed.

[0012] In an alternative embodiment, the method comprises mixing 500 ml of the imidazolium ionic liquid, 5-15 ml of the first titanium oxychloride solution and 0.8-1.2 L of soft water, heating to 70-90 °C and maintaining for 15-30 minutes, and then cooling to 50-60 °C, and then adding 200-400 ml of the second titanium oxychloride solution under a vacuum degree of -0.08 to -0.9 MPa, adjusting the evaporation amount to maintain the volume of the system unchanged until the reaction is completed.

[0013] In a second aspect, the present application provides a metatitanic acid slurry prepared by the method for preparing a metatitanic acid slurry according to any one of the preceding embodiments.

[0014] In a third aspect, the present application provides a method for preparing rutile titanium dioxide, comprising the method for preparing a metatitanic acid slurry according to any one of the preceding embodiments.

[0015] In an alternative embodiment, the method comprises sequentially drying and calcining the metatitanic acid slurry.

[0016] Preferably, the method comprises drying the metatitanic acid slurry at 100-120 °C for 10-14 hours, and then calcining at 750-850 °C for 0.5-1 hour.

[0017] In a fourth aspect, the present application provides a rutile titanium dioxide prepared by the method for preparing rutile titanium dioxide according to the preceding embodiments.

[0018] Preferably, the rutile titanium dioxide is in the shape of a long strip.

[0019] The present application has the following beneficial effects: the embodiment of the present application forms hydrochloric acid solution by hydrolysis of titanium oxychloride to release hydrogen chloride under low-acid condition and through evaporation of the hydrochloric acid, so that the hydrolysis-evaporation continues to circulate, the system is stable, and metatitanic acid slurry formed by complete hydrolysis of titanium oxychloride is obtained. Meanwhile, the imidazole ionic liquid as a template agent makes the aspect ratio of the titanium dioxide particles formed subsequently controllable, and finally forms long strip-shaped rutile titanium dioxide with uniform morphology and size and controllable aspect ratio, which has good pigment performance. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0021] Figure 1 The scanning electron microscope image of titanium dioxide provided for Example 1 of the present application;

[0022] Figure 2 The scanning electron microscope image of titanium dioxide provided for Comparative Example 1;

[0023] Figure 3 The scanning electron microscope image of titanium dioxide provided for Comparative Example 2. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely. The specific conditions not mentioned in the embodiments are carried out according to conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments not mentioned by the manufacturer are all conventional products that can be purchased in the market.

[0025] The present embodiment provides a preparation method of metatitanic acid slurry, comprising:

[0026] The imidazole ionic liquid and the first titanium oxychloride solution are mixed and heated to form seed crystals. At this time, the imidazole ionic liquid acts as a template agent to form seed crystals with a small amount of titanium oxychloride solution. The heating treatment includes heating to 70-90℃ and maintaining for 15-30 minutes, and then cooling to 50-60℃.

[0027] Specifically, the temperature of heating is 70℃, 75℃, 80℃, 85℃ and 90℃, etc. any value between 70-90℃, and the holding time is 15 minutes, 20 minutes, 25 minutes and 30 minutes, etc. any value between 15-30 minutes. The cooling temperature is 50℃, 51℃, 52℃, 53℃, 54℃, 55℃, 56℃, 57℃, 58℃, 59℃ and 60℃, etc. any value between 50-60℃.

[0028] Further, it comprises mixing the imidazolium ionic liquid, the first titanium oxychloride solution and soft water, heating to 70-90℃ and holding for 15-30 minutes, and then cooling to 50-60℃.

[0029] Specifically, 500ml of the imidazolium ionic liquid, 5-15ml of the first titanium oxychloride solution and 0.8-1.2L of soft water are mixed, heated to 70-90℃ and held for 15-30 minutes, and then cooled to 50-60℃.

[0030] The first titanium oxychloride solution is prepared by hydrochloric acid extraction method, and the specific operation of the hydrochloric acid extraction method is known in the art and will not be described in detail in the embodiments of the present application.

[0031] The imidazolium ionic liquid used includes but is not limited to 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate. That is, the above-mentioned imidazolium compounds are only examples of imidazolium ionic liquids targeted by the present application, and other imidazolium ionic liquids in the prior art can also be used.

[0032] Soft water can also be other water.

[0033] The above-mentioned 500ml of the imidazolium ionic liquid, 5-15ml of the first titanium oxychloride solution and 0.8-1.2L of soft water are only indicative of the ratio between the substances, and do not mean that only the above-mentioned volumes can be used, as long as the volume ratio range between the above-mentioned substances is met. For example, the volume ratio of imidazolium ionic liquid, first titanium oxychloride solution and water can be 33:1:67, 100:1:200, 33:1:100, 100:1:67, 50:1:150, 50:1:100, etc. any value between 33-100:1:67-200.

[0034] Then, under the condition of reduced pressure distillation, the second titanium oxychloride solution is added, and the evaporation amount is adjusted to maintain the volume of the system unchanged, so that the crystal seed grows. Specifically, then, under the vacuum degree of -0.08 to -0.9 Mpa, the second titanium oxychloride solution is added, and the evaporation amount is adjusted to maintain the volume of the system unchanged until the reaction is completed. Further specifically, then, under the vacuum degree of -0.08 to -0.9 Mpa, 200-400 ml of the second titanium oxychloride solution is added, and the evaporation amount is adjusted to maintain the volume of the system unchanged until the reaction is completed.

[0035] The vacuum degree can be -0.08 Mpa, -0.1 Mpa, -0.2 Mpa, -0.3 Mpa, -0.4 Mpa, -0.5 Mpa, -0.6 Mpa, -0.7 Mpa, -0.8 Mpa, and -0.9 Mpa, or any value between -0.08 and -0.9 Mpa.

[0036] The amount of the second titanium oxychloride solution is not limited to 200-400 ml, as long as the volume ratio of the second titanium oxychloride solution to the imidazole ionic liquid is 1:0.4-0.8, and other amounts can also be used. The second titanium oxychloride solution is also obtained by hydrochloric acid extraction, and even the first and second titanium oxychloride solutions are the same batch of materials obtained by hydrochloric acid extraction.

[0037] In a second aspect, the present application provides a metatitanic acid slurry prepared by the preparation method of the metatitanic acid slurry according to any one of the preceding embodiments.

[0038] In a third aspect, the present application provides a preparation method of rutile titanium dioxide, which comprises the preparation method of the metatitanic acid slurry according to any one of the preceding embodiments.

[0039] Specifically, after the reaction is completed, the reaction system is filtered and washed, and then dried and calcined. Specifically, the metatitanic acid slurry is dried at 100-120℃ for 10-14 hours, and then calcined at 750-850℃ for 0.5-1 hour.

[0040] The drying temperature can be 100℃, 105℃, 110℃, 115℃, and 120℃, or any value between 100-120℃. The drying time can be 10 hours, 11 hours, 12 hours, 13 hours, and 14 hours, or any value between 10-14 hours. The calcination temperature can be 750℃, 780℃, 800℃, 830℃, and 850℃, or any value between 750-850℃. The calcination time can be 0.5 hours, 0.75 hours, and 1 hour, or any value between 0.5-1 hour.

[0041] In a fourth aspect, the present application provides a rutile titanium dioxide prepared by the method for preparing rutile titanium dioxide according to the preceding embodiments, wherein the rutile titanium dioxide is strip-shaped.

[0042] In summary, the titanium dioxide prepared by the hydrochloric acid extraction method according to the embodiments of the present application is used as a template, and the particles grow stably under a continuous and stable hydrolysis condition, thereby forming uniform titanium dioxide particles with a certain aspect ratio.

[0043] The features and performances of the present application are further described in detail below in combination with embodiments.

[0044] Embodiment 1

[0045] The present embodiment provides a method for preparing titanium dioxide, comprising:

[0046] The process of forming titanium oxychloride by the hydrochloric acid extraction method is as follows: 500 g of high-titanium slag is taken, 1500 g of 37% concentrated hydrochloric acid is added, stirring is performed, and the temperature is raised to 60℃, while hydrogen chloride gas is continuously introduced into the system to maintain the acid value of the system and keep the pressure of the system at 1.0 MPa, the reaction is stopped after 9 h, 40 g of NaClO3 is added after the system is cooled to room temperature, stirring is continued for 1 h, then pressure filtration is performed, and the filter residue is washed to neutral; (2) at 30℃, TBP / MIBK (wt) = 1:1 is used as the extractant, the oil phase to water phase ratio O / A = 2:1, and after 3-stage extraction, the oil phase is the iron extraction phase, and the water phase is the titanium-containing raffinate phase; (3) the iron extraction phase is back-extracted with deionized water at O / A = 1:10, the oil phase extractant is returned to the Fe extraction device, and then the water phase containing iron is purified by the same extraction-back extraction as (2) and (3), part of the water is evaporated for concentration, the iron content is 160 g / L, and multi-stage countercurrent extraction V is performed with the extractant TBP / dimethylbenzene = 4:25, O / A = 2:1, the raffinate liquid enters the impurity removal extractor, Mn is extracted with TOA / toluene = 1:9, O / A = 2:1, and after the extraction liquid is back-extracted, the raffinate liquid is the TiOCl2 rich in titanium, and the Ti content can reach 100000 ppm, and the water phase raffinate liquid rich in titanium is added to the titanium extraction device, extraction is performed with TOA / toluene = 1:9, O / A = 2:1, and the organic phase containing high-purity titanium ions (the content of colored impurity metals is lower than the detection limit) is obtained.

[0047] 500 ml of imidazole ionic liquid, 10 ml of the above titanium oxychloride solution, and 1 L of soft water are added to a reaction container, and then heated to 80℃ and maintained for 20 minutes, and then cooled to 60℃. The imidazole ionic liquid is 1-butyl-3-methylimidazolium chloride.

[0048] The vacuum degree is kept at -0.09 Mpa, 300 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 110°C for 12 hours, and finally, calcination is performed at 800°C for 0.5 hours to obtain the titanium dioxide pigment.

[0049] Example 2

[0050] The present example provides a method for preparing titanium dioxide, comprising:

[0051] 500 ml of imidazole ionic liquid, 15 ml of the above titanium oxychloride solution, and 1.2 L of soft water are added to a reaction container, and then heated to 90°C and kept for 15 minutes, and then cooled to 55°C. The imidazole ionic liquid is selected from 1-butyl-3-methylimidazolium chloride.

[0052] The vacuum degree is kept at -0.08 Mpa, 400 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 120°C for 10 hours, and finally, calcination is performed at 750°C for 1 hour to obtain the titanium dioxide pigment.

[0053] Example 3

[0054] The present example provides a method for preparing titanium dioxide, comprising:

[0055] 500 ml of imidazole ionic liquid, 5 ml of the above titanium oxychloride solution, and 1 L of soft water are added to a reaction container, and then heated to 70°C and kept for 30 minutes, and then cooled to 50°C. The imidazole ionic liquid is selected from 1-butyl-3-methylimidazolium hexafluorophosphate.

[0056] The vacuum degree is kept at -0.5 Mpa, 250 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 100°C for 14 hours, and finally, calcination is performed at 850°C for 0.5 hours to obtain the titanium dioxide pigment.

[0057] Example 4

[0058] The present example provides a method for preparing titanium dioxide, comprising:

[0059] 500 ml of imidazole ionic liquid, 12 ml of the above titanium oxychloride solution, and 1.1 L of soft water are added to a reaction container, and then heated to 85°C and kept for 25 minutes, and then cooled to 55°C. The imidazole ionic liquid is selected from 1-butyl-3-methylimidazolium hexafluorophosphate.

[0060] The vacuum degree is kept at -0.9 MPa, 350 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 105 DEG C for 13 hours, and finally, calcination is performed at 820 DEG C for 0.75 hours to obtain titanium dioxide pigment.

[0061] Comparative Example 1

[0062] 10 ml of the above titanium oxychloride solution and 1 L of soft water are added into the reaction container, and then heated to 80 DEG C and kept for 20 minutes, and then cooled to 60 DEG C.

[0063] The vacuum degree is kept at -0.09 MPa, 300 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 110 DEG C for 12 hours, and finally, calcination is performed at 800 DEG C for 0.5 hours to obtain titanium dioxide pigment.

[0064] Comparative Example 2

[0065] 500 ml of imidazole ionic liquid, 10 ml of titanium tetrachloride solution (commercially available titanium tetrachloride) and 1 L of soft water are added into the reaction container, and then heated to 80 DEG C and kept for 20 minutes, and then cooled to 60 DEG C. The imidazole ionic liquid is selected from 1-butyl-3-methylimidazolium hexafluorophosphate.

[0066] The vacuum degree is kept at -0.09 MPa, 300 ml of the above titanium oxychloride solution is slowly added, and the evaporation amount is adjusted to keep the volume of the system unchanged. After the reaction is completed, filtration and washing are performed. Then, drying is performed at 110 DEG C for 12 hours, and finally, calcination is performed at 800 DEG C for 0.5 hours to obtain titanium dioxide pigment.

[0067] Detection Example 1

[0068] The titanium dioxide prepared in Example 1 and Comparative Examples 1 and 2 is detected by scanning electron microscopy, and the results are shown in Figure 1 , Figure 2 and Figure 3 . According to Figure 1 , Figure 2 and Figure 3 , the preparation method provided by the embodiments of the present application can form long strip-shaped titanium dioxide, and the particle size is controllable. Changes in other conditions all affect the shape of the particles.

[0069] Detection Example 2

[0070] The titanium dioxide of Example 1 and Comparative Examples 1 and 2 is subjected to conventional performance testing. As shown in Table 1:

[0071] Table 1 is the conventional performance testing of titanium dioxide

[0072] Whiteness Relative color reduction L a b Example 1 93.28 103 99.21 -0.52 1.02 Comparative Example 1 92.42 98 98.89 -0.46 1.08 Comparative Example 2 92.81 100 99.10 -0.48 1.14

[0073] Note: The relative color strength test is with the market product R706 as the reference standard. It can be seen from Table 1 that the long strip-shaped titanium dioxide prepared in Example 1 has good pigment performance.

[0074] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a metatitanic acid slurry, characterized in that, include: Imidazole-based ionic liquid and a first titanium oxychloride solution were mixed and heated to form seed crystals. Then, a second titanium oxychloride solution was added under a vacuum of -0.08 to -0.9 MPa, and the evaporation rate was adjusted to maintain a constant system volume, allowing the seed crystals to grow. Both the first and second titanium oxychloride solutions were prepared by hydrochloric acid extraction. The imidazole ionic liquid is selected from 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium tetrafluoroborate and 1-butyl-3-methylimidazolium hexafluorophosphate.

2. The method for preparing metatitanic acid slurry according to claim 1, characterized in that, The concentrations of the first and second titanium oxychloride solutions are 80-250 g / L.

3. The method for preparing metatitanic acid slurry according to claim 1, characterized in that, The concentrations of the first and second titanium oxychloride solutions are 160-250 g / L.

4. The method for preparing metatitanic acid slurry according to claim 1, characterized in that, The heat treatment involves heating to 70-90°C and holding for 15-30 minutes, then cooling to 50-60°C.

5. The method for preparing metatitanic acid slurry according to claim 1, characterized in that, include: The imidazole ionic liquid, the first titanium oxychloride solution, and soft water are mixed and heated to 70-90°C and maintained for 15-30 minutes. Then, the mixture is cooled to 50-60°C. The second titanium oxychloride solution is then added under a vacuum of -0.08 to -0.9 MPa, and the evaporation rate is adjusted to maintain a constant volume of the system until the reaction is complete.

6. The method for preparing metatitanic acid slurry according to claim 1, characterized in that, include: Mix 500 ml of the imidazole ionic liquid, 5-15 ml of the first titanium oxychloride solution, and 0.8-1.2 L of soft water. Heat the mixture to 70-90°C and maintain the temperature for 15-30 minutes. Then cool the mixture to 50-60°C. Next, under a vacuum of -0.08 to -0.9 MPa, add 200-400 ml of the second titanium oxychloride solution. Adjust the evaporation rate to maintain a constant volume of the system until the reaction is complete.

7. A metatitanic acid slurry, characterized in that, It is prepared by the method for preparing metatitanic acid slurry according to any one of claims 1-6.

8. A method for preparing rutile titanium dioxide, characterized in that, It includes the method for preparing the metatitanic acid slurry according to any one of claims 1-6.

9. The preparation method according to claim 8, characterized in that, include: The metatitanic acid slurry was subsequently dried and calcined.

10. The preparation method according to claim 9, characterized in that, include: The metatitanic acid slurry is dried at 100-120℃ for 10-14 hours, and then calcined at 750-850℃ for 0.5-1 hour.

11. A rutile titanium dioxide, characterized in that, It is prepared by the method for preparing rutile titanium dioxide as described in any one of claims 8-10.

12. The rutile titanium dioxide according to claim 11, characterized in that, The rutile titanium dioxide is elongated.

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