Method for improving concentration of chlorination process titanium dioxide sanding slurry
By adjusting the proportion and pH value of the dispersant and the titanium dioxide chloride primary product under the conditions of alkaline ethanol aqueous solution, and performing sand dispersion, the problem of insufficient slurry concentration after the titanium dioxide silt of chloride chloride is solved, a more uniform film layer and better pigment performance and application performance are achieved, while improving production efficiency.
Patent Information
- Application Number
- CN202411692411.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-21
AI Technical Summary
The slurry concentration of titanium dioxide silt is insufficient after the chlorination method is sand-milled, which affects the pigment performance and application performance of titanium dioxide products.
By mixing the dispersant and the titanium dioxide chloride primary product under the conditions of alkaline ethanol aqueous solution, and controlling the mass ratio of ethanol to deionized water, the mass ratio of titanium dioxide chloride primary product to the ethanol aqueous solution, the pH value of the slurry before sanding, etc., sand milling and dispersing, the slurry concentration is greater than 460 g/L.
The slurry concentration and dispersion stability after chlorination titanium dioxide silt sand grinding are improved, making the titanium dioxide film layer after inorganic coating more uniform, improving the pigment performance and application performance of titanium dioxide products, and at the same time shortening the mixing time before sand grinding and dispersion, improving production efficiency.
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Figure SMS_1
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of titanium dioxide production, in particular to a method for increasing the concentration of titanium dioxide sand-grinding slurry produced by a chloride process. Background Art
[0002] The particle size of industrial-grade titanium dioxide is generally 150-350 nm, and it has a high surface energy, so it is very easy to agglomerate. Before the inorganic coating is applied to the surface, the titanium dioxide particles must be dispersed as much as possible to keep the original particle state as much as possible, otherwise it will not only affect the uniformity of the coating, but also directly affect the scattering of light by the pigment particles, thereby reducing the optical properties and performance of the pigment, and may even damage the coating in the subsequent air flow crushing process, thereby affecting the weather resistance of titanium dioxide. Therefore, sand grinding dispersion is crucial to the production of high-quality titanium dioxide.
[0003] Sand milling dispersion is to add the titanium dioxide primary product and dispersant into water, and then use a high-speed rotating dispersion disc or dispersion rod to drive the small diameter grinding medium to rotate, break up the agglomerated particles, and gradually grind the titanium dioxide particles into spheres, so that the particle size distribution tends to be concentrated, and the dispersion effect is stable and lasting, so as to ensure that the coated product has excellent physical and chemical properties. The sand milling slurry concentration reflects the particle size distribution and dispersion stability of the titanium dioxide slurry. The higher the slurry concentration, the narrower the particle size distribution of the titanium dioxide slurry, the better the dispersion stability, and the more uniform the titanium dioxide film layer after inorganic coating. At present, the slurry concentration of chloride titanium dioxide after sand milling dispersion is between 350-450 g / L. The uniformity of the titanium dioxide film layer after inorganic coating is not very good, which affects the pigment performance and application performance of titanium dioxide products.
[0004] Therefore, how to increase the slurry concentration of chloride titanium dioxide after sand grinding has become an urgent problem to be solved. Summary of the invention
[0005] In view of this, the technical problem to be solved by the present invention is to provide a method for increasing the sand-grinding slurry concentration of chloride-process titanium dioxide, so that the slurry concentration after sand-grinding dispersion can be greater than 460 g / L.
[0006] To achieve the above object, the present invention provides a method for increasing the concentration of chloride titanium dioxide sand grinding slurry, comprising the following steps:
[0007] S1) adjusting the pH value of deionized water to 13.0-14.0 with an alkaline compound, and adding a certain amount of ethanol to obtain an alkaline ethanol aqueous solution;
[0008] S2) mixing the alkaline ethanol aqueous solution, dispersant and primary product of chloride-process titanium dioxide to obtain a slurry before sand grinding;
[0009] S3) adding zirconium beads to the above slurry before sand grinding to disperse it by sand grinding, and obtaining sand grinding slurry after screening.
[0010] Preferably, the alkaline compound is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a mass fraction of 10% to 30%.
[0011] Preferably, the mass ratio of the ethanol to the deionized water is (0.1-0.5):1.
[0012] Preferably, the average particle size of the initial product of titanium dioxide produced by the chloride process is 180-230 nm.
[0013] Preferably, the mass ratio of the initial product of the chloride process titanium dioxide to the ethanol aqueous solution is preferably (0.5-0.6):1.
[0014] Preferably, the dispersant includes one or more of sodium silicate, sodium hexametaphosphate, sodium polycarboxylate and ammonium polyacrylate; the added amount of the dispersant is 0.2% to 0.4% of the initial quality of the chloride process titanium dioxide.
[0015] Preferably, the pH value of the slurry before sand grinding is controlled at 11.0-11.5.
[0016] Preferably, the mass ratio of the zirconium beads to the primary product of the chloride process titanium dioxide is (1.0-2.0):1, and the rotation speed during the sand milling dispersion is 2600-3000 r / min.
[0017] Compared with the prior art, the method provided by the present invention can improve the concentration and dispersion stability of the slurry of the chloride process titanium dioxide after sand milling by mixing the dispersant and the primary product of the chloride process titanium dioxide under the condition of alkaline ethanol aqueous solution, and control the mass ratio of ethanol to deionized water, the mass ratio of the primary product of the chloride process titanium dioxide to the ethanol aqueous solution, the pH value of the slurry before sand milling, etc., so as to make the titanium dioxide film layer after inorganic coating more uniform, thereby ensuring the pigment performance and application performance of the titanium dioxide product. On the other hand, the method provided by the present invention can shorten the mixing time before sand milling dispersion while ensuring the sand milling dispersion effect, thereby improving production efficiency. DETAILED DESCRIPTION
[0018] In order to further illustrate the present invention, the following is a detailed description in conjunction with the embodiments. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, rather than limiting the claims of the invention.
[0019] The present invention provides a method for increasing the concentration of chloride titanium dioxide sand grinding slurry, comprising the following steps:
[0020] S1) adjusting the pH value of deionized water to 13.0-14.0 with an alkaline compound, and adding a certain amount of ethanol to obtain an alkaline ethanol aqueous solution;
[0021] S2) mixing the alkaline ethanol aqueous solution, dispersant and primary product of chloride-process titanium dioxide to obtain a slurry before sand grinding;
[0022] S3) adding zirconium beads to the above slurry before sand grinding to disperse it by sand grinding, and obtaining sand grinding slurry after screening.
[0023] In the method provided by the present invention, the alkaline compound in step S1) is preferably a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a mass fraction of 10% to 30%, and specifically can be a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a mass fraction of 10%, 15%, 20%, 25% or 30%.
[0024] In the method provided by the present invention, the mass ratio of the ethanol to the deionized water in step S1) is preferably (0.1-0.5):1, and can be appropriately increased according to the increase in the mass of the primary product of the chloride process titanium dioxide.
[0025] In some specific embodiments of the present invention, the above steps S1), S2) and S3) are all performed in a sand milling and dispersing device.
[0026] Optionally, during the process of adjusting the pH value in the above step S1), a stirrer and a pH meter are started.
[0027] In the method provided by the present invention, in step S2), the average particle size of the primary product of the chloride process titanium dioxide is preferably controlled to be 180-230 nm.
[0028] In the method provided by the present invention, the mass ratio of the primary product of titanium dioxide produced by the chloride process to the ethanol aqueous solution in step S2) is preferably (0.5-0.6):1, specifically 0.5:1, 0.55:1 or 0.6:1.
[0029] The present invention has no particular limitation on the dispersant, which may be any suitable dispersant known to those skilled in the art, preferably including one or more of sodium silicate, sodium hexametaphosphate, sodium polycarboxylate and ammonium polyacrylate.
[0030] The added amount of the dispersant is preferably 0.2% to 0.4% of the initial quality of the chloride titanium dioxide powder, specifically 0.2%, 0.3% or 0.4%, which can be selected according to the average particle size of the initial quality of the chloride titanium dioxide powder.
[0031] In the step S2), the mixing time is preferably 5 to 15 min, more preferably 10 min.
[0032] The present invention has no particular limitation on the mixing method, and the mixing method may be any mixing method known to those skilled in the art, including but not limited to stirring and mixing.
[0033] The present invention controls the addition amounts of the alkaline compound, the dispersant and the primary product of the chloride process titanium dioxide so that the pH value of the slurry before sand grinding is 11.0-11.5.
[0034] In the method provided by the present invention, the mass ratio of the zirconium beads to the initial product of the chloride process titanium dioxide in step S3) is preferably (1.0-2.0):1.
[0035] The particle size of the zirconium beads is preferably 0.4-0.8 mm, more preferably 0.4-0.6 mm.
[0036] Preferably, the sand mill has a rotation speed of 2600-3000 r / min, specifically 2700, 2800, 2900 or 3000 r / min.
[0037] The sand grinding time is preferably 20 to 40 min, specifically 20, 30 or 40 min.
[0038] The present invention has no special limitation on the screening in the above step S3), and it can be a screening method well known to those skilled in the art, including but not limited to vibrating screen screening and the like.
[0039] Preferably, after sand-milling and dispersion, a 500-mesh vibrating screen is used for sieving to obtain a sand-milled slurry.
[0040] All raw materials of the present invention are not particularly limited in their sources, and can be purchased from the market or prepared according to conventional methods known to those skilled in the art. For greater clarity, the following examples are provided for detailed description.
[0041] Example 1
[0042] 909 g of deionized water was added to the sand mill dispersing device, the agitator and the pH meter were started, 25 mL of 10% sodium hydroxide solution was added to adjust the pH value of the deionized water to 13.0-14.0, and 91 g of ethanol was added; 1.5 g of sodium silicate dispersant and 500 g of primary chloride titanium dioxide were added, and the mixture was stirred for 10 min to control the pH value of the slurry at 11.0-11.5; 500 g of zirconium beads with a diameter of 0.4-0.6 mm were added, the sand milling speed was 2700 r / min, the sand milling time was 20 min, and after sand milling, a 500-mesh sieve was used to sieve to obtain the sand milled slurry.
[0043] Example 2
[0044] Add 693 g of deionized water to the sand mill dispersing device, start the agitator and the pH meter, add 15 mL of 20% sodium hydroxide solution to adjust the pH value of the deionized water to 13.0-14.0, add 207 g of ethanol; then add 1.5 g of sodium polycarboxylate dispersant and 500 g of primary chloride titanium dioxide, stir for 10 min, and control the pH value of the slurry at 11.0-11.5; add 600 g of zirconium beads with a diameter of 0.4-0.6 mm, the sand mill speed is 2800 r / min, the sand mill time is 30 min, and after sand milling, use a 500-mesh sieve to obtain a sand milled slurry.
[0045] Example 3
[0046] 556 g of deionized water was added to the sand mill dispersing device, the agitator and the pH meter were started, 10 mL of 30% sodium hydroxide solution was added to adjust the pH value of the deionized water to 13.0-14.0, and 277 g of ethanol was added; 1.0 g of sodium silicate, 0.5 g of ammonium polyacrylate dispersant and 500 g of primary chloride titanium dioxide were added, and the mixture was stirred for 10 min to control the pH value of the slurry at 11.0-11.5; 800 g of zirconium beads with a diameter of 0.4-0.6 mm were added, the sand milling speed was 3000 r / min, the sand milling time was 40 min, and after sand milling, a 500-mesh sieve was used to obtain the sand milled slurry.
[0047] Comparative Example 1
[0048] Add 1000 g of deionized water to the sand mill dispersion device, start the agitator and pH meter, add 20 mL of 10% sodium hydroxide solution to adjust the pH value of the deionized water to 12.0, and stir for 15 min; add 1.5 g of sodium silicate dispersant and stir for 15 min; add 500 g of primary chloride titanium dioxide and stir for 30 min; add 500 g of zirconium beads with a diameter of 0.4-0.6 mm, the sand mill speed is 2700 r / min, the sand mill time is 60 min, and after sand milling, use a 500-mesh sieve to obtain a sand milled slurry.
[0049] Comparative Example 2
[0050] 833 g of deionized water was added to the sand mill dispersion device, the agitator and the pH meter were started, and 7 mL of 30% sodium hydroxide solution was added to adjust the pH value of the deionized water to 12.0; 1.0 g of sodium silicate, 0.5 g of ammonium polyacrylate dispersant and 500 g of primary chloride titanium dioxide were added, and stirred for 10 min; 800 g of zirconium beads with a diameter of 0.4-0.6 mm were added, the sand mill speed was 2000 r / min, the sand milling time was 40 min, and after sand milling, a 500-mesh sieve was used to sieve to obtain a sand milled slurry.
[0051] The mass concentration and Zeta potential of the sand-milled slurries obtained in the above Examples 1-3 and Comparative Examples 1-2 were tested, and the results are shown in Table 1:
[0052] Table 1 Mass concentration and Zeta potential of slurry after sand grinding
[0053]
[0054] As can be seen from Table 1, the mass concentration of the sand-milled slurry obtained by the method for increasing the concentration of chloride-process titanium dioxide sand-milled slurry provided by the present invention is greater than 460 g / L, and the absolute value of the Zeta potential is greater than 40 mV, both of which are better than the comparative example, indicating that the particle size distribution of the titanium dioxide particles in the slurry is concentrated and the dispersion stability is good.
[0055] The present invention can improve the slurry concentration and dispersion stability of the chloride process titanium dioxide after sand grinding by mixing a dispersant and a preliminary product of the chloride process titanium dioxide under alkaline ethanol aqueous solution conditions, and control the mass ratio of ethanol to deionized water, the mass ratio of the preliminary product of the chloride process titanium dioxide to the ethanol aqueous solution, the pH value of the slurry before sand grinding, etc., so as to make the titanium dioxide film layer after inorganic coating more uniform, thereby ensuring the pigment performance and application performance of the titanium dioxide product; the method of the present invention can shorten the mixing time before sand grinding dispersion while ensuring the sand grinding dispersion effect, thereby improving production efficiency.
[0056] The above embodiments are only used to help understand the method and core idea of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.
Claims
1. A method for increasing the concentration of chloride titanium dioxide sand mill slurry, characterized in that: The following steps are involved: S1) adjusting the pH value of deionized water to 13.0-14.0 with an alkaline compound, and adding a certain amount of ethanol to obtain an alkaline ethanol aqueous solution; S2) mixing the alkaline ethanol aqueous solution, dispersant and primary product of chloride-process titanium dioxide to obtain a slurry before sand grinding; S3) adding zirconium beads to the above slurry before sand grinding to disperse it by sand grinding, and obtaining sand grinding slurry after screening.
2. The method according to claim 1, characterized in that: The alkaline compound is a sodium hydroxide aqueous solution or a potassium hydroxide aqueous solution with a mass fraction of 10% to 30%.
3. The method according to claim 1, characterized in that The mass ratio of the ethanol to the deionized water is (0.1-0.5):
1.
4. The method according to claim 1, characterized in that: The average particle size of the initial product of the chloride process titanium dioxide is 180-230 nm.
5. The method according to claim 1, characterized in that The mass ratio of the initial product of the chloride process titanium dioxide to the ethanol aqueous solution is (0.5-0.6):
1.
6. The method according to claim 1, characterized in that The dispersant includes one or more of sodium silicate, sodium hexametaphosphate, sodium polycarboxylate and ammonium polyacrylate; the added amount of the dispersant is 0.2% to 0.4% of the initial quality of the chloride titanium dioxide.
7. The method according to claim 1, characterized in that The pH value of the slurry before sand grinding is controlled at 11.0-11.
5.
8. The method according to claim 1, characterized in that: The mass ratio of the zirconium beads to the initial product of the chloride process titanium dioxide is (1.0-2.0):1, and the rotation speed during the sand mill dispersion is 2600-3000 r / min.