Glass filter material and preparation method thereof

Abstract

The present invention discloses a glass filter material and a preparation method thereof, and belongs to the field of water treatment technology. The preparation method comprises the following steps: spraying a nano-dispersion liquid on the surface of glass particles, followed by drying and sintering. The product obtained by the preparation method is sieved into four grades, namely 0.1-0.4 mm, 0.4-0.8 mm, 0.8-2.0 mm and 2.0-4.0 mm, to adapt to different filtration precisions. The present invention, by introducing a nano-dispersion liquid, gives the glass particles a larger specific surface area in the form of "addition", and at the same time makes them have the characteristics of high filtration precision, antibacterial, oleophobic, etc., and the production process is simple and the manufacturing cost is low.

Description

Technical Field

[0001] The invention belongs to the technical field of water treatment, and in particular relates to a glass filter material and a preparation method thereof. Background Art

[0002] Filtration is a widely used process in water treatment. Filter materials can intercept suspended impurities in water, reducing COD and BOD, heavy metal ion concentrations, oil content, and color. Traditional water filter media typically utilize materials such as quartz sand, anthracite, and ceramsite. However, these materials suffer from low filtration accuracy, a short service life, and the need for frequent backwashing. Activated carbon filter media can improve filtration accuracy, but its micro- and nano-scale pore structure is easily clogged by small organic molecules, reducing filtration efficiency.

[0003] Glass is a potentially high-quality filter material due to its acid and alkali resistance and recyclability. However, using glass particles directly as filter media still results in low filtration accuracy. Appropriate methods are needed to "expand" and treat the glass particles with anti-fouling agents, such as increasing the specific surface area of ​​the glass particles and imbuing the glass surface with negative charges and antibacterial and antimicrobial materials, to achieve high filtration accuracy and a long service life.

[0004] Patent CN111097230B discloses boiling the screened glass filter material in distilled water for 30 minutes, repeatedly rinsing it with distilled water, drying it at a high temperature of 110°C, and then soaking it in a 1 mol / L hydrogen chloride (HCl) solution for 24-36 hours after cooling. This requires a long acid treatment process, a lengthy process, and the waste acid solution needs to be disposed of during the specific implementation process.

[0005] Patent CN110548339A discloses placing nitrogen-dried glass slag into 100 ml of anthropic acid solution (concentrated sulfuric acid and hydrogen peroxide in a volume ratio of 7:3), followed by water bathing at 95° C. for 2 hours. The waste acid solution still needs to be disposed of.

[0006] Patent CN113735462B discloses placing waste glass particles in a piranha solution, subjecting them to surface hydroxylation treatment at 90°C for 30 minutes, washing them with water until the washing solution is neutral, and then drying them at 100°C for 2 hours to obtain hydroxylated waste glass. During the implementation of this patent, the waste acid solution also needs to be disposed of. Summary of the Invention

[0007] The purpose of the present invention is to provide a glass filter material and a preparation method thereof. By introducing a nano-dispersion liquid, the glass particles are given a larger specific surface area in the form of "addition", and at the same time, the glass filter material has the characteristics of high filtration accuracy, antibacterial and oleophobicity, and the production process is simple and the manufacturing cost is low.

[0008] To achieve the above objectives, the present invention adopts the following specific technical solutions:

[0009] The invention provides a method for preparing a glass filter material. The method comprises the following steps: spraying a nanometer dispersion liquid on the surface of glass particles, and then drying and sintering the glass filter material.

[0010] Furthermore, the glass particles have a particle size of 0.1-4.0 mm.

[0011] Furthermore, the glass particles are subjected to surface cleaning treatment.

[0012] Optionally, the surface cleaning process includes plasma cleaning or ultraviolet irradiation; further, the plasma cleaning time is 1-10 seconds.

[0013] Furthermore, the preparation method of the nano-dispersion liquid includes: configuring fumed silica, aluminum oxide, zinc oxide, titanium oxide and water into an aqueous solution according to weight parts, grinding to ensure that the nano-powder is fully dispersed, deagglomerated and broken up the agglomerated particles, and then adding silica sol and water, stirring to obtain a nano-dispersion liquid with a silica sol concentration of 5-35%, containing powder particles ranging in size from a few nanometers to more than one micron.

[0014] Preferably, the D50 of the fumed silica is 20-100 nm and the BET specific surface area is 115-135 m 2 / g.

[0015] Preferably, the particle size of the alumina is 100-2000 nm and the BET specific surface area is 5-10 m 2 By adding alumina particles ranging from several hundred to thousands of nanometers and grading them with particles of different sizes such as silica sol and fumed silica, a surface morphology with a rich structure is ultimately formed, greatly improving the material's ability to hold and absorb pollutants, resulting in a high-precision filter material.

[0016] Preferably, the particle size of the zinc oxide is less than 100 nm. Zinc oxide is a common antibacterial material that destroys the structure and metabolism of bacteria through various mechanisms such as photocatalysis, ion dissolution and electron transfer, thereby inhibiting bacterial growth and reproduction.

[0017] Preferably, the titanium oxide includes two crystal structures, rutile and anatase, with a particle size of less than 50 nm. Preferably, P25 (a titanium dioxide having an anatase crystal and a rutile crystal mixed phase with an average particle size of 25 nm) is used. When anatase titanium dioxide is subjected to light with an energy greater than its energy band, electrons and holes are generated, which react with water and oxygen to produce active components such as active hydroxyl radicals and peroxides. These active components have strong reactivity, particularly active hydroxyl radicals, which have an energy of 120 kal / mol. The covalent bonds of carbon-carbon, carbon-nitrogen, carbon-hydrogen, oxygen-hydrogen, and nitrogen-hydrogen that constitute organic compounds have a binding energy of about 100 kal / mol, meaning that these active hydroxyl radicals can decompose organic compounds.

[0018] Furthermore, in parts by weight, the fumed silica, aluminum oxide, zinc oxide, titanium oxide and water are 1-50 parts, 1-10 parts, 0.1-20 parts, 0.1-20 parts and 100-800 parts respectively.

[0019] Furthermore, the ratio of the glass particles to the nano-dispersion liquid is 8-12 g / ml.

[0020] Furthermore, the drying temperature is 80-250° C., and the drying time is 5-60 minutes.

[0021] Furthermore, the sintering temperature is 500-700°C for 5-30 minutes, which softens the surface of the glass particles and allows the nanoparticles to bond with the glass, forming a coating with a strong structure. The coating contains particles ranging from a few nanometers to tens of nanometers, which impart a negative charge to the glass particles in aqueous solution. This negative charge has the same electrical properties as the particles in the water being filtered and purified, repelling each other and preventing them from adsorbing on the surface of the glass particles.

[0022] The present invention also provides a glass filter material. The product prepared by the preparation method is sieved into four grades, namely 0.1-0.4 mm, 0.4-0.8 mm, 0.8-2.0 mm and 2.0-4.0 mm, so as to adapt to different filtering precisions.

[0023] Compared to existing technologies, this invention utilizes a dispersion containing nano-sized silicon oxide, zinc oxide, titanium oxide, aluminum oxide, and silica sol, sprayed onto the surface of glass particles, followed by drying and sintering. This creates a complex, rough surface structure on the glass particles. Specifically, nanoparticles of varying sizes and functions form a rough surface structure on the glass particles, with dimensions ranging from a few nanometers to over a micron horizontally and from a few nanometers to over a micron vertically. The result is a glass particle filter material with high filtration accuracy, antibacterial properties, and oleophobic properties. The invention boasts a simple process and low production costs. DETAILED DESCRIPTION

[0024] The embodiments of the present invention will be described in detail below with reference to specific examples, but those skilled in the art will appreciate that the following examples are intended only to illustrate the present invention and should not be construed as limiting the scope of the present invention. Where specific conditions are not specified in the examples, the methods were performed according to conventional conditions or the conditions recommended by the manufacturer. Where the manufacturers of the reagents or instruments are not specified, they are all conventional products that can be purchased commercially.

[0025] In the following examples or comparative examples, the aluminum oxide was ALMATIS CT3000 (D50 = 0.4 μm, D90 = 1.3 μm, Bet 7.5 μm). 2 / g); fumed silica uses Cabot TS-610 (D50 = 50nm, Bet specific surface area of ​​120 ± 15m 2 / g); zinc oxide uses Aladdin Z141332 (0-100nm); titanium oxide uses Degussa's Evonik P25.

[0026] In the following examples and comparative examples, filtration precision refers to the following: filtration of sewage using 0.1-0.4 mm glass particle filter media, and testing of the resulting water sample using a laser particle size analyzer. D97 refers to the particle size value corresponding to the cumulative distribution percentage from small to large reaching 97% in the particle size distribution, and the number of particles smaller than D97 accounts for 97% of the total particle number.

[0027] The shading rate refers to: using a laser particle size analyzer to test the treated water sample, the amount of water sample added each time is consistent. The smaller the shading rate value, the higher the clarity and transparency of the water sample, that is, the better the filtration effect.

[0028] Example 1

[0029] A method for preparing a glass filter material:

[0030] (1) 3 g of fumed silica, 3 g of aluminum oxide, 0.2 g of zinc oxide, 0.1 g of P25, and 6.3 ml of water were prepared into a 50% aqueous solution and ground for 4 hours to fully disperse the nanopowders and reduce agglomeration; then 75 g of commercially available weakly acidic 40% silica sol was added and stirred to mix evenly, and then 12.4 ml of pure water was added and stirred for 30 minutes to obtain a nano-dispersion liquid with a silica sol concentration of 30%.

[0031] (2) Clean glass particles with a particle size of 0.1-4.0 mm are used as raw materials and plasma cleaning is performed for 3 seconds to clean the surface.

[0032] (3) Take 1000g of glass particles, spray 100ml of the above-mentioned nano-dispersion liquid while stirring, then dry at 120℃ for 30min, sinter at 600℃ for 25min, and cool to obtain the glass filter material. The obtained glass filter material is sieved into four grades, namely 0.1-0.4mm, 0.4-0.8mm, 0.8-2.0mm and 2.0-4.0mm, to adapt to different filtration precisions. Among them, the filtration precision of the glass filter material of 0.1-0.4mm grade is 0.95 microns; the filtration precision of the glass filter material of 0.4-0.8mm grade is about 3.0 microns. The specific filtration effect is shown in Table 1.

[0033] Example 2

[0034] A method for preparing a glass filter material:

[0035] (1) 2 g of fumed silica, 2 g of aluminum oxide, 0.1 g of zinc oxide, 0.1 g of P25, and 4.2 ml of water were prepared into a 50% aqueous solution and ground for 4 hours to fully disperse the nanopowders and reduce agglomeration; then 87.5 g of commercially available weakly acidic 40% silica sol was added and stirred to mix evenly, and then 4.1 ml of pure water was added and stirred for 30 minutes to obtain a nano-dispersion liquid with a silica sol concentration of 35%.

[0036] (2) Clean glass particles with a particle size of 0.1-4.0 mm are used as raw materials and plasma cleaning is performed for 3 seconds to clean the surface.

[0037] (3) 1000 g of glass particles were sprayed with 100 ml of the above nano-dispersion while stirring, followed by drying at 120° C. for 30 min, sintering at 600° C. for 25 min, and cooling to obtain the glass filter material.

[0038] The resulting glass filter material was sieved into four grades: 0.1-0.4mm, 0.4-0.8mm, 0.8-2.0mm, and 2.0-4.0mm, to accommodate different filtration accuracies. The 0.1-0.4mm grade of glass filter material achieved a filtration accuracy of 1.7 microns. The specific filtration results are shown in Table 1.

[0039] Example 3

[0040] A method for preparing a glass filter material:

[0041] (1) 4 g of fumed silica, 3 g of aluminum oxide, 0.1 g of zinc oxide, 0.1 g of P25, and 7.2 ml of water were prepared into a 50% aqueous solution and ground for 4 hours to fully disperse the nanopowders and reduce agglomeration. Subsequently, 50 g of commercially available weakly acidic 40% silica sol was added and stirred to mix evenly. 35.6 ml of pure water was added and stirring was continued for 30 minutes to obtain a nano-dispersion liquid with a silica sol concentration of 20%.

[0042] (2) Clean glass particles with a particle size of 0.1-4.0 mm are used as raw materials and plasma cleaning is performed for 3 seconds to clean the surface.

[0043] (3) 1000 g of glass particles were sprayed with 100 ml of the above nano-dispersion while stirring, followed by drying at 120° C. for 30 min, sintering at 600° C. for 25 min, and cooling to obtain the glass filter material.

[0044] The resulting glass filter material was sieved into four grades: 0.1-0.4mm, 0.4-0.8mm, 0.8-2.0mm, and 2.0-4.0mm, to accommodate different filtration accuracies. The 0.1-0.4mm grade of glass filter material achieved a filtration accuracy of 5.3 microns. The specific filtration results are shown in Table 1.

[0045] Example 4

[0046] A method for preparing a glass filter material:

[0047] (1) 3 g of fumed silica, 3 g of aluminum oxide, 0.2 g of zinc oxide, 0.1 g of P25, and 6.3 ml of water were prepared into a 50% aqueous solution and ground for 4 hours to fully disperse the nanopowders and reduce agglomeration; then 75 g of commercially available weakly acidic 40% silica sol was added and stirred to mix evenly, and then 12.4 ml of pure water was added and stirred for 30 minutes to obtain a nano-dispersion liquid with a silica sol concentration of 30%.

[0048] (2) Clean glass particles with a particle size of 0.1-4.0 mm are used as raw materials and plasma cleaning is performed for 5 seconds to clean the surface.

[0049] (3) 800 g of glass particles were sprayed with 100 ml of the above nano-dispersion while stirring, followed by drying at 100° C. for 60 min, sintering at 650° C. for 20 min, and cooling to obtain the glass filter material.

[0050] The resulting glass filter media was sieved into four grades: 0.1-0.4mm, 0.4-0.8mm, 0.8-2.0mm, and 2.0-4.0mm, to accommodate different filtration accuracies. The 0.1-0.4mm grade of glass filter media achieved a filtration accuracy of 0.94 microns. The specific filtration results are shown in Table 1.

[0051] Example 5

[0052] A method for preparing a glass filter material:

[0053] (1) 3 g of fumed silica, 3 g of aluminum oxide, 0.2 g of zinc oxide, 0.1 g of P25, and 6.3 ml of water were prepared into a 50% aqueous solution and ground for 4 hours to fully disperse the nanopowders and reduce agglomeration; then 75 g of commercially available weakly acidic 40% silica sol was added and stirred to mix evenly, and then 12.4 ml of pure water was added and stirred for 30 minutes to obtain a nano-dispersion liquid with a silica sol concentration of 30%.

[0054] (2) Clean glass particles with a particle size of 0.1-4.0 mm are used as raw materials and plasma cleaning is performed for 3 seconds to clean the surface.

[0055] (3) 1200 g of glass particles were sprayed with 100 ml of the above nano-dispersion while stirring, followed by drying at 220° C. for 5 min, sintering at 550° C. for 30 min, and cooling to obtain the glass filter material.

[0056] The resulting glass filter material was sieved into four grades: 0.1-0.4mm, 0.4-0.8mm, 0.8-2.0mm, and 2.0-4.0mm, to accommodate different filtration accuracies. The 0.1-0.4mm grade of glass filter material achieved a filtration accuracy of 1.12 microns. The specific filtration results are shown in Table 1.

[0057] Comparative Example 1

[0058] The difference from Example 1 is that only silica sol solution is used instead of the nano-dispersion liquid in Example 1. The specific filtration effect is shown in Table 1.

[0059] Comparative Example 2

[0060] The difference from Example 1 is that the glass particles are not treated in any way. The specific filtering effects are shown in Table 1.

[0061] Table 1 Comparison of glass filter material formulations and filtration effects of Examples 1-5 and Comparative Examples 1-2

[0062]

[0063]

[0064] As can be seen from Table 1, the glass filter materials prepared in Examples 1-5 use a dispersion containing nano-sized silicon oxide, zinc oxide, titanium oxide, aluminum oxide, and silica sol, which is sprayed on the surface of the glass particles and then dried and sintered. A rough surface with a complex structure is formed on the surface of the glass particles. The filter materials have high filtration accuracy and very low shading rate, especially Examples 1 and 4, where the filtration accuracy reaches below 1 μm.

[0065] Comparative Example 1 used only a silica sol solution. Due to the small and concentrated silica particles, a rough surface structure could not be provided. The material's dirt-holding capacity was limited, preventing improved filtration accuracy and resulting in a high light-blocking rate. In Comparative Example 5, since the glass particles were not treated in any way, the filtration accuracy was similar to that of ordinary quartz sand, and the light-blocking rate was also high.

[0066] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that the technical solutions described in the aforementioned embodiments may be modified, or some or all of the technical features therein may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the various embodiments of the present invention. Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, the combination of features from different embodiments is intended to be within the scope of the present invention and to form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background technology of the present invention and should not be construed as an admission or any form of implication that such information constitutes prior art already known to those skilled in the art.

Claims

1. A method for preparing a glass filter material, characterized in that: The nano-dispersion liquid is sprayed on the surface of the glass particles, followed by drying and sintering; The preparation method of the nano-dispersion liquid comprises: preparing an aqueous solution of fumed silica, aluminum oxide, zinc oxide, titanium oxide and water according to parts by weight, grinding and fully dispersing the solution, then adding silica sol and water, stirring and preparing a nano-dispersion liquid with a silica sol concentration of 5-35%; The D50 of the fumed silica is 20-50 nm, and the BET specific surface area is 115-135 m 2 / g; The particle size of the alumina is 100-2000 nm, and the BET specific surface area is 5-10 m 2 / g; The particle size of the zinc oxide is less than 100 nm; The titanium oxide includes two crystal structures, rutile and anatase, and its particle size is less than 50nm; In parts by weight, the fumed silica, aluminum oxide, zinc oxide, titanium oxide and water are 1-50 parts, 1-10 parts, 0.1-20 parts, 0.1-20 parts and 100-800 parts respectively.

2. The preparation method according to claim 1, characterized in that The glass particles have a particle size of 0.1-4.0 mm.

3. The preparation method according to claim 1, characterized in that The glass particles are subjected to surface cleaning treatment; The surface cleaning treatment includes plasma cleaning or ultraviolet irradiation; The plasma cleaning time is 1-10 seconds.

4. The preparation method according to claim 1, characterized in that The ratio of the glass particles to the nano-dispersion liquid is 8-12 g / ml.

5. The preparation method according to claim 1, characterized in that The drying temperature is 80-250° C., and the drying time is 5-60 minutes.

6. The preparation method according to claim 1, characterized in that The sintering temperature is 500-700° C., and the sintering time is 5-30 minutes.

7. A glass filter material, characterized in that: The product obtained by the preparation method according to any one of claims 1 to 6 is sieved into four grades, namely 0.1-0.4 mm, 0.4-0.8 mm, 0.8-2.0 mm and 2.0-4.0 mm, to adapt to different filtration accuracies.

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