阅读说明：本技术 细化二氧化硅的方法、超细二氧化硅粉末和用途 (Method for refining silicon dioxide, ultrafine silicon dioxide powder and use ) 是由 王益庆 沈家锋 王帅 邵进 于 2020-12-16 设计创作，主要内容包括：本发明提供了一种细化二氧化硅的方法、超细二氧化硅粉末和用途,将二氧化硅配制成悬浮液,加入活化剂与表面活性剂,再加入碱调节pH,将上述悬浮液搅拌均匀后,经球磨机研磨处理,再经砂磨机研磨,得到二氧化硅分散液。二氧化硅分散液中加入改性剂,将物料混合均匀后分散液通入高压二流体喷雾干燥塔内,干燥得到二氧化硅粉末。干燥后的二氧化硅粉末,加入改性剂,在高速混合机中混合改性,得到超细二氧化硅粉末。本发明的方法能得到的粉末材料粒径超细且分布均匀,表面改性效果好,工艺设备成熟度高,易于工业化,产品可适用于涂料、油墨、橡胶制品、胶黏剂、硅橡胶制品等。(The invention provides a method for refining silicon dioxide, superfine silicon dioxide powder and application, which comprises the steps of preparing silicon dioxide into suspension, adding an activating agent and a surfactant, adding alkali to adjust pH, uniformly stirring the suspension, grinding by a ball mill, and grinding by a sand mill to obtain silicon dioxide dispersion. Adding a modifier into the silicon dioxide dispersion liquid, uniformly mixing the materials, introducing the dispersion liquid into a high-pressure two-fluid spray drying tower, and drying to obtain silicon dioxide powder. Adding a modifier into the dried silicon dioxide powder, and mixing and modifying in a high-speed mixer to obtain the superfine silicon dioxide powder. The powder material obtained by the method has superfine and uniform particle size distribution, good surface modification effect, high maturity of process equipment and easy industrialization, and the product can be suitable for coatings, printing ink, rubber products, adhesives, silicon rubber products and the like.)

1. A method of refining silica, comprising the steps of:

(a) adding an activating agent and a surfactant into a silicon dioxide suspension, adjusting the pH of the suspension to be 4-10, and uniformly mixing;

wherein the activating agent comprises one or more of sodium hexametaphosphate, ethylenediamine phosphate, sodium tripolyphosphate, sodium metaaluminate, sodium pyrophosphate and sodium polyacrylate;

the surfactant comprises one or more of linear alkyl benzene sulfonate, fatty alcohol-polyoxyethylene ether sodium sulfate, fatty alcohol-polyoxyethylene ether ammonium sulfate, sodium lauryl sulfate, lauroyl glutamic acid, nonylphenol polyoxyethylene ether, diethanol amide stearic acid monoglyceride, lignosulfonate, heavy alkylbenzene sulfonate, alkyl sulfonate, a dispersing agent NNO, a dispersing agent MF, alkyl polyether and fatty alcohol-polyoxyethylene ether;

preferably, the addition amount of the activating agent is 0.1 to 5 percent, preferably 2 to 4 percent of the mass of the silicon dioxide;

preferably, the addition amount of the surfactant is 0.1 to 5 percent, preferably 2 to 4 percent, of the mass of the silicon dioxide;

preferably, the suspension of silica has a solids content of 0.1% to 55%;

(b) grinding the suspension obtained in the step (a) to obtain a silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(c) adding a modifier into the dispersion liquid, uniformly mixing, and then carrying out spray drying to obtain 2-7 mu m silicon dioxide powder;

the modifier is an organosilane modifier;

preferably, the temperature of the spray drying is 150-300 ℃, and the more preferable temperature is 200-250 ℃;

preferably, the addition amount of the organosilane modifier is 0-30% of the mass of the silica, preferably 0.01-30%, more preferably 0.1-15%, more preferably 1-20%, and more preferably 5-25%;

(d) mixing the silicon dioxide powder with a modifier, and modifying at 70-200 ℃;

the modifier is an organosilane modifier;

preferably, the mixing and the modifying are performed in a mixer.

2. The method for refining silicon dioxide according to claim 1, wherein the silicon dioxide is white carbon black prepared by a precipitation method, preferably, the white carbon black comprises one or a combination of several of powdered white carbon black, granulated white carbon black and white carbon black slurry;

preferably, the specific surface area of the white carbon black is 50-500m²(ii)/g, more preferably 100-400m²/g。

3. The method of refining silica according to claim 1, wherein in step (c), the spray drying is operated in a two-fluid spray drying tower using a two-fluid atomizer;

preferably, the gas of the two fluids comprises one or a combination of several of air, oxygen, nitrogen and carbon dioxide;

preferably, the airflow pressure of the two fluids is 0.05-3.5MP, and the airflow pressure is 1-3 MPa.

4. A method for refining silica according to claim 1, wherein in steps (c) and (d) the organosilane modifying agent comprises one or a combination of aminosilane coupling agent, silazane, aluminate coupling agent, silane coupling agent and titanate coupling agent.

5. The method of refining silica according to claim 1, wherein in step (b), the grinding specifically comprises: firstly, ball milling and then sanding;

preferably, the ball milling time is 0.1-4h, the treatment temperature is 25-95 ℃, and more preferably, the ball milling time is 1-2h, and the treatment temperature is 45-80 ℃;

preferably, the sanding time is 0.1 to 4 hours, more preferably 1 to 2 hours.

6. A method for refining silica according to claim 5 wherein said ball milled grinding media are 1-5mm zirconium beads.

7. A method of refining silica according to claim 5, wherein the sanded grinding media are 0.01-0.1mm zirconium beads.

8. A method for refining silica according to claim 1, characterized in that in step (d), the organosilane modifier is added in an amount of 0-20% by mass of the silica powder, preferably in an amount of 0.01-20%, more preferably in an amount of 0.1-15%, more preferably in an amount of 1-10%, more preferably in an amount of 5-15%.

9. An ultrafine silica powder which is obtained by the method for refining silica according to any one of claims 1 to 8.

10. Use of the ultrafine silica powder according to claim 9 for the preparation of coatings, inks, rubbers, plastics, heat-insulating materials.

Technical Field

The invention relates to the technical field of fine chemical engineering application, in particular to a method for refining silicon dioxide, ultrafine silicon dioxide powder and application.

Background

Ultrafine silicon dioxide belongs to the field of fine chemical engineering application, and ultrafine SiO₂The inorganic non-metallic powder is amorphous white powder (i.e. an aggregate thereof), is a non-toxic, tasteless and pollution-free inorganic non-metallic material, has large specific surface area, small density, good dispersibility and wide application field, can be applied to the fields of building industry, medicines, aerospace products and the like, can be applied to products such as coating, printing ink, rubber, plastics, heat insulation materials and the like, and can be used as products such as a delustering agent, a reinforcing machine, a thickening agent, an anticaking agent and the like.

The preparation method of the superfine silicon dioxide comprises a physical method and a chemical method. Physical methods generally refer to mechanical crushing; chemical methods include vapor deposition, precipitation, sol-gel, ion exchange, and the like. The gas phase method has the problems of complex process, large equipment investment and the like, and the quality of the product is poor by the sol-gel method.

At present, the superfine silicon dioxide with lower cost is mostly obtained by mechanically crushing silicon dioxide by a precipitation method, but the superfine silicon dioxide has the problems of less varieties, unstable quality, small void ratio, wide particle size distribution, poor surface modification effect, low yield and the like.

In view of the above, the present invention is particularly proposed.

Disclosure of Invention

The method for refining the silicon dioxide provided by the invention can refine silicon dioxide particles to 2-7 mu m, and the obtained superfine silicon dioxide powder has the advantages of small particles, uniform particle size distribution, stable quality, small porosity, high yield, good surface modification effect and the like.

In order to achieve the above purpose of the present invention, the following technical solutions are adopted:

a method of refining silica comprising the steps of:

(a) adding an activating agent and a surfactant into a silicon dioxide suspension, adjusting the pH of the suspension to be 4-10, and uniformly mixing;

wherein the activating agent comprises one or more of sodium hexametaphosphate, ethylenediamine phosphate, sodium tripolyphosphate, sodium metaaluminate, sodium pyrophosphate and sodium polyacrylate;

the surfactant comprises one or more of linear alkyl benzene sulfonate, fatty alcohol-polyoxyethylene ether sodium sulfate, fatty alcohol-polyoxyethylene ether ammonium sulfate, sodium lauryl sulfate, lauroyl glutamic acid, nonylphenol polyoxyethylene ether, diethanol amide stearic acid monoglyceride, lignosulfonate, heavy alkylbenzene sulfonate, alkyl sulfonate, a dispersing agent NNO, a dispersing agent MF, alkyl polyether and fatty alcohol-polyoxyethylene ether;

preferably, the addition amount of the activating agent is 0.1 to 5 percent, preferably 2 to 4 percent of the mass of the silicon dioxide;

preferably, the addition amount of the surfactant is 0.1 to 5 percent, preferably 2 to 4 percent, of the mass of the silicon dioxide;

preferably, the suspension of silica has a solids content of 0.1% to 55%;

(b) grinding the suspension obtained in the step (a) to obtain a silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(c) adding a modifier into the dispersion liquid, uniformly mixing, then carrying out spray drying to obtain 2-7 mu m silicon dioxide powder, and drying;

the modifier is an organosilane modifier;

preferably, the addition amount of the organosilane modifier is 0-30% of the mass of the silica, preferably 0.01-30%, more preferably 0.1-15%, more preferably 1-20%, and more preferably 5-25%;

preferably, the temperature of the spray drying is 150-300 ℃, and the more preferable temperature is 200-250 ℃;

(d) mixing the silicon dioxide powder with a modifier, and modifying at 70-200 ℃;

the modifier is an organosilane modifier;

preferably, the mixing and the modifying are performed in a mixer.

Preferably, the silica is white carbon black prepared by a precipitation method, and more preferably, the white carbon black comprises one or a combination of more of powdered white carbon black, granulated white carbon black and white carbon black slurry;

preferably, the specific surface area of the white carbon black is 50-500m²(ii)/g, more preferably 100-400m²/g。

Preferably, in step (c), the spray drying is carried out using a two-fluid atomizer in a two-fluid spray drying tower;

more preferably, the gas of the two fluids comprises one or a combination of several of air, oxygen, nitrogen and carbon dioxide;

more preferably, the gas flow pressure of the two fluids is 0.05-3.5MP, and more preferably the gas flow pressure is 1-3 MPa.

Preferably, in step (c) and step (d), the organosilane modifier comprises one or more of aminosilane coupling agent, silazane, aluminate coupling agent, silane coupling agent and titanate coupling agent.

Preferably, in step (b), the grinding specifically comprises: firstly, ball milling and then sanding;

more preferably, the ball milling time is 0.1-4h, the treatment temperature is 25-95 ℃, and more preferably, the ball milling time is 1-2h, and the treatment temperature is 45-80 ℃;

more preferably, the sanding time is between 0.1 and 4 hours, and more preferably between 1 and 2 hours.

Preferably, the ball-milled grinding media are 1-5mm zirconium beads.

Preferably, the sanded grinding media are 0.01 to 0.1mm zirconium beads.

Preferably, in step (d), the amount of the organosilane modifier added is 0 to 20% by mass of the silica, preferably 0.01 to 20%, more preferably 0.1 to 15%, still more preferably 1 to 10%, still more preferably 5 to 15%.

The superfine silicon dioxide powder is obtained by adopting the method for refining the silicon dioxide.

The superfine silicon dioxide powder is used for preparing coatings, printing ink, rubber, plastics and heat insulation materials.

Compared with the prior art, the invention has the beneficial effects that:

(1) the method for thinning the silicon dioxide provided by the invention is convenient, simple and easy to operate, and can thin the silicon dioxide particles to 2-7 mu m.

(2) The method for refining the silicon dioxide provided by the invention has high equipment maturity, is easy to industrialize, and can be applied to the production fields of coatings, printing inks, rubber products, adhesives, silicon rubber products and the like.

(3) The superfine silicon dioxide powder provided by the invention has the advantages of small particles, uniform particle size distribution, stable quality, small porosity, high yield, good surface modification effect and the like.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following detailed description, but those skilled in the art will understand that the following described examples are some, not all, of the examples of the present invention, and are only used for illustrating the present invention, and should not be construed as limiting the scope of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The method for refining the silicon dioxide provided by the invention is simple and easy to operate, and specifically comprises the following steps:

(a) adding an activating agent and a surfactant into a silica suspension, adjusting the pH of the suspension to 4-10 (for example, 4, 5, 6, 7, 8, 9 and 10) to improve the stability of the suspension, and uniformly mixing;

the activating agent is used for reducing the viscosity of the suspension and comprises one or more of sodium hexametaphosphate, ethylenediamine phosphate, sodium tripolyphosphate, sodium metaaluminate, sodium pyrophosphate and sodium polyacrylate;

the surfactant can improve the stability of the suspension, and simultaneously emulsify a modifier added later, and fully contact with white carbon black, specifically, the surfactant comprises one or a combination of more of Linear Alkylbenzene Sulfonate (LAS), fatty alcohol-polyoxyethylene ether sodium sulfate (AES), fatty alcohol-polyoxyethylene ether ammonium sulfate (AESA), sodium lauryl sulfate (K12 or SDS), lauroyl glutamic acid, nonylphenol polyoxyethylene (10) ether (TX-10), diethanolamide (6501) stearic acid monoglyceride, lignosulfonate, heavy alkylbenzene sulfonate, alkylsulfonate (petroleum sulfonate), a diffusant NNO, a diffusant MF, alkyl polyether (PO-EO copolymer) and fatty alcohol-polyoxyethylene ether;

in some preferred embodiments of the invention, the activator is added in an amount of 0.1% to 5% (e.g., 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%) by mass of the silica, preferably 2% to 4%;

in some preferred embodiments of the invention, the surfactant is added in an amount of 0.1% to 5% (e.g., 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%) by mass of the silica, preferably 2% to 4%;

in some preferred embodiments of the invention, the suspension of silica has a solids content of 0.1% to 55% (e.g., 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%);

(b) grinding the suspension obtained in the step (a) to obtain a silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(c) adding a modifier into the dispersion liquid obtained in the step (b), uniformly mixing, then carrying out spray drying to obtain 2-7 mu m silicon dioxide powder, and drying;

the modifier is an organosilane modifier and comprises one or a combination of more of an aminosilane coupling agent, a silazane, an aluminate coupling agent, a silane coupling agent and a titanate coupling agent;

in some preferred embodiments of the invention, the temperature of the spray drying is 150-300 ℃ (e.g., 150, 200, 250, 300 ℃), more preferably 200-250 ℃;

(d) mixing the dried silica powder of step (c) with a modifier and modifying at 70-200 ℃ (e.g., 70, 100, 150, 200 ℃);

the modifier is an organosilane modifier and comprises one or a combination of more of an aminosilane coupling agent, a silazane, an aluminate coupling agent, a silane coupling agent and a titanate coupling agent.

In some preferred embodiments of the invention, the organosilane modifier is added in an amount of 0 to 30% by mass of the silica, preferably in an amount of 0.01% to 30%, more preferably in an amount of 0.1% to 15%, more preferably in an amount of 1% to 20%, more preferably in an amount of 5% to 25%;

in some preferred embodiments of the present invention, the dried silica powder is subjected to high speed mixing and modification in a mixer.

In some preferred embodiments of the present invention, the silica is white carbon black prepared by a precipitation method, and more preferably, the white carbon black includes one or a combination of powdered white carbon black, granulated white carbon black and white carbon black slurry;

preferably, the specific surface area of the white carbon black is 50-500m²(ii)/g, more preferably 100-400m²/g。

In some preferred embodiments of the invention, in step (c), the spray drying is carried out using a two-fluid atomizer in a two-fluid spray drying tower;

more preferably, the gas of the two fluids comprises one or a combination of several of air, oxygen, nitrogen and carbon dioxide;

more preferably, the airflow pressure of the two fluids is 0.05-3.5MP, and more preferably the airflow pressure is 1-3 MPa.

In some preferred embodiments of the present invention, in steps (c) and (d), the organosilane modifier comprises: .

In some preferred embodiments of the present invention, in step (b), the grinding specifically comprises: firstly, ball milling and then sanding;

more preferably, the ball milling time is 0.1-4h, the treatment temperature is 25-95 ℃, and more preferably, the ball milling time is 1-2h, and the treatment temperature is 45-80 ℃;

more preferably, the time of the sand mill is 0.1 to 4 hours, and more preferably the time is 1 to 2 hours.

Preferably, the ball-milled grinding media are 1-5mm zirconium beads.

Preferably, the sanded grinding media are 0.01 to 0.1mm zirconium beads.

In some preferred embodiments of the present invention, in step (d), the organosilane modifier is added in an amount of 0-20% by mass of the silica, preferably in an amount of 0.01-20%, more preferably in an amount of 0.1-15%, more preferably in an amount of 1-10%, more preferably in an amount of 5-15%.

The superfine silicon dioxide powder is obtained by adopting the method for refining the silicon dioxide. The material has the advantages of small particles, uniform particle size distribution, stable quality, small porosity, high yield, good surface modification effect and the like.

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products commercially available.

Example 1

(1) Preparing precipitated silica into a suspension with solid content of 1%, adding sodium hexametaphosphate accounting for 0.1% of the mass of the silica and linear alkyl sodium benzene sulfonate accounting for 0.1% of the mass of the silica, and adding alkali to adjust the pH value to 4;

(2) uniformly stirring the suspension, grinding for 0.1h by using a ball mill, wherein the grinding medium of the ball mill is 1mm of zirconium beads, the treatment temperature is 25 ℃, and then grinding for 0.1h by using a sand mill to obtain silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(3) adding an organosilane modifier accounting for 0.01 percent of the mass of the silicon dioxide into the silicon dioxide dispersion liquid, and uniformly mixing the materials;

(4) introducing the modified dispersion liquid in the step (3) into a high-pressure two-fluid spray drying tower, wherein the airflow pressure of the two fluids is 0.05-3.5MPa, and the dispersion liquid is dried at the temperature of 150-;

wherein the second fluid is air;

(5) and adding 0.01 percent of modifier into the dried silicon dioxide powder, and mixing and modifying in a high-speed mixer at the modification temperature of 70 ℃ to obtain the superfine silicon dioxide powder.

Example 2

(1) Preparing precipitated silicon dioxide into suspension with solid content of 55%, adding ethylene diamine phosphate accounting for 5% of the mass of the silicon dioxide and lauroyl glutamic acid accounting for 5%, and adding alkali to adjust the pH value to 10;

wherein the silica is white carbon black prepared by precipitation method, and the specific surface area is 50m²/g；

(2) Uniformly stirring the suspension, grinding for 4h by using a ball mill at the treatment temperature of 95 ℃ with the ball-milled grinding medium being 5mm zirconium beads, and grinding for 0.1-4h by using a sand mill with the sand-milled grinding medium being 0.1mm zirconium beads to obtain silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(3) adding 30% of organosilane modifier into the silicon dioxide dispersion liquid, and uniformly mixing the materials;

(4) introducing the modified dispersion liquid obtained in the step (3) into a high-pressure two-fluid spray drying tower, wherein the airflow pressure of two fluids is 3.5MPa, and drying the dispersion liquid at 300 ℃ to obtain silicon dioxide powder with the particle size of 2-7 mu m; wherein the second fluid is oxygen;

(5) and adding 20% of organosilane modifier into the dried silicon dioxide powder, and mixing and modifying in a high-speed mixer at the modification temperature of 200 ℃ to obtain the superfine silicon dioxide powder.

Example 3

(1) Preparing precipitated silica into a suspension with solid content of 25%, adding sodium pyrophosphate of which the mass is 1% of that of the silica and nonylphenol polyoxyethylene of which the mass is 1%, and adding alkali to adjust the pH to 8;

wherein, the silicon dioxide is the granulated white carbon black prepared by a precipitation method, and the specific surface area is 500m²/g；

(2) Uniformly stirring the suspension, grinding for 1h by using a ball mill at the treatment temperature of 75 ℃ with the ball-milled grinding medium being 3mm zirconium beads, and grinding for 2h by using a sand mill with the sand-milled grinding medium being 0.03mm zirconium beads to obtain silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(3) adding 20% of organosilane modifier into the silicon dioxide dispersion liquid, and uniformly mixing the materials;

(4) introducing the modified dispersion liquid obtained in the step (3) into a high-pressure two-fluid spray drying tower, wherein the airflow pressure of two fluids is 1MPa, and drying the dispersion liquid at 200 ℃ to obtain silicon dioxide powder with the particle size of 2-7 mu m; wherein the second fluid is nitrogen;

(5) and adding 10% of organosilane modifier into the dried silicon dioxide powder, and mixing and modifying in a high-speed mixer at the modification temperature of 100 ℃ to obtain the superfine silicon dioxide powder.

Example 4

(1) Preparing precipitated silica into a suspension with the solid content of 15%, adding sodium polyacrylate with the mass of 3% of silica and 3% of a diffusant NNO, and adding alkali to adjust the pH to 6;

wherein, the silicon dioxide is the granulated white carbon black prepared by a precipitation method, and the specific surface area is 200m²/g；

(2) Uniformly stirring the suspension, grinding for 2h by using a ball mill at the treatment temperature of 55 ℃ with the ball-milled grinding medium being 2mm zirconium beads, and grinding for 3h by using a sand mill with the sand-milled grinding medium being 0.07mm zirconium beads to obtain silicon dioxide dispersion liquid with the particle size of 0.03-2 mu m;

(3) adding 7% of organosilane modifier into the silicon dioxide dispersion liquid, and uniformly mixing the materials;

(4) introducing the modified dispersion liquid obtained in the step (3) into a high-pressure two-fluid spray drying tower, wherein the airflow pressure of two fluids is 2MPa, and the dispersion liquid is dried at 250 ℃ to obtain silicon dioxide powder with the particle size of 2-7 mu m; wherein the second fluid is CO₂；

(5) Adding 12% of organosilane modifier into the dried silicon dioxide powder, and mixing and modifying in a high-speed mixer at the modification temperature of 150 ℃ to obtain the superfine silicon dioxide powder.

While particular embodiments of the present invention have been illustrated and described, it will be appreciated that the above embodiments are merely illustrative of the technical solution of the present invention and are not restrictive; those of ordinary skill in the art will understand that: modifications may be made to the above-described embodiments, or equivalents may be substituted for some or all of the features thereof without departing from the spirit and scope of the present invention; the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention; it is therefore intended to cover in the appended claims all such alternatives and modifications that are within the scope of the invention.