CN111943717A - Silver-loaded diatom shell antibacterial ceramic filter element and preparation method thereof - Google Patents
Silver-loaded diatom shell antibacterial ceramic filter element and preparation method thereof Download PDFInfo
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Abstract
The invention relates to a silver-loaded diatom shell antibacterial ceramic filter element and a preparation method thereof, wherein the preparation method comprises the following steps: for silver-carrying frustulesAnd sequentially mixing, grinding, liquid-phase mixing and drying raw material particles, and then performing hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element. Different from the prior art in which a blank is firstly made and then sintered and molded, the preparation method adopts the hot-pressing sintering treatment which is carried out simultaneously by pressing and sintering, so that the sintering temperature is lower, the porous structure of the silver-loaded diatom shell can be ensured not to be damaged, and the compressive strength of the ceramic filter element can be greatly improved; moreover, the nano-silver loading capacity of the prepared silver-loaded diatom shell antibacterial ceramic filter element is 0.15-0.4%, the filter element has excellent adsorption performance, the filtering precision is as high as 10-100 mu m, and the specific surface area can reach 65m2The water quality safety ceramic filter element has the advantages of sterilizing and inactivating, ensuring the water quality safety of domestic water, prolonging the service life of the ceramic filter element and further increasing the market competitiveness of products.
Description
Technical Field
The invention relates to the technical field of domestic water purification, in particular to a silver-loaded diatom shell antibacterial ceramic filter element and a preparation method thereof.
Background
Along with the improvement of the life quality of people, the standards of people for drinking water are higher and higher, and the drinking water is required to be non-toxic, harmless and odorless and also contains certain mineral substances and trace elements, so that the drinking water can be directly drunk by people and is beneficial to body health. However, as water pollution increases, obtaining safe water has become a worldwide problem, and particularly, even if the content of microorganisms such as viruses and bacteria in water is small, various diseases are induced once the microorganisms enter the human body. The traditional drinking water purifying agent mainly comprises chlorine and hypochlorous acid, has good killing effect on microorganisms such as bacteria and the like, but cannot remove heavy metals and particle pollutants in water, and has a series of problems of long water purifying time, large using amount, toxic impurity introduction and the like. The activated carbon has excellent micropore structural characteristics and surface chemical activity, can efficiently adsorb heavy metal ions and organic matters in water, and is often used as a domestic water filter element. However, since the activated carbon filter element is a passive filter element material and is very easy to be saturated and adsorbed, harmful substances can re-enter the drinking water if the activated carbon filter element is not cleaned in time, and in addition, the activated carbon filter element accumulating a large amount of organic substances can promote a large amount of harmful bacteria to propagate, so that the water purification capacity is reduced and even secondary water pollution is caused.
At present, researchers have developed a ceramic filter element which is mainly used for filtering, resisting bacteria and activating drinking water, can effectively remove harmful residual chlorine, suspended pollutants, organic chemical substances, colors and peculiar smells, and further can filter out the drinking water which reaches a certain drinking standard. The ceramic filter element can be applied to industries such as water purifiers, barreled water and dual water supply, and can also be applied to other occasions with corresponding requirements on water quality supply. However, the ceramic filter element generally adopts silver as an antibacterial material, but the silver is expensive and is easily oxidized in a high-temperature oxidation environment, so that the preparation cost and the use cost of the ceramic filter element are high, and the antibacterial performance cannot be effectively guaranteed.
The frustules are purely naturally-generated nano-materials, have excellent mechanical properties, rich micropore-mesopore structures (2-100 nm) and huge specific surface areas (100-600 m)2/g), has excellent filtering effect and adsorption function, and has been widely used in photoelectric devices, anode materials, dye-sensitized solar cells, and adsorption materials. Moreover, the silicon hydroxyl Si-OH on the surface of the microporous-mesoporous structure of the diatom shell is beneficial to Ag+The attachment to the surface is mainly by silver-carrying treatment under alkaline conditions3)2]+Or AgOH is attached to the surface of the pore structure and then is converted into nano silver through roasting, thereby realizing the inactivation of bacteria attached to the surface of the frustules. The prior art has disclosed ceramic filter elements with silver-loaded diatomaceous earth, which have good water purification effects and increase the working life of the ceramic filter elements.
For example, CN105152639A discloses a diatomite-based ceramic filter element and a preparation method thereof, wherein the preparation method comprises the following steps: raw material components such as diatomite, bacteriostatic agent and the like are stirred into slurry after being ball-milled, then the slurry is poured into a gypsum mould and a hollow ceramic filter element blank is obtained, then the ceramic filter element blank is dried and sintered and formed in a vacuum reaction sintering furnace, wherein the bacteriostatic agent comprises solid particles such as shell powder, the surface of which is sprayed with silver ion slurry. The preparation method adopts a process of firstly preparing blank and then sintering and forming, the sintering temperature is up to 810-870 ℃, so that the compressive strength of the prepared ceramic filter core is low, the porous structure of diatomite in the ceramic filter core is seriously damaged, and the antibacterial and water purification performances are reduced; in addition, the prepared ceramic filter element contains components such as shell powder and the like, and inevitably contains heavy metals which are unfavorable to human health, such as copper, lead, hexavalent chromium and the like, so that the use of the ceramic filter element is greatly limited, and the ceramic filter element is not favorable for large-scale popularization and use.
CN107602101A discloses a high-efficiency bacteriostatic ceramic filter element and a preparation method thereof, wherein the preparation method comprises the following steps: mixing raw material components such as diatomite, a bacteriostatic agent and the like, adding water glass to obtain mixed powder, then sequentially adding water for wetting, drying and sieving to obtain treated mixed powder, then performing extrusion molding according to the shape specification of the filter element and drying to obtain a filter element green body, and finally calcining and molding under the atmosphere of inert gas. The preparation method adopts a process of firstly preparing blank and then sintering and forming, the sintering temperature is up to 950-1050 ℃, which not only causes the low compressive strength of the prepared ceramic filter element, but also can seriously damage the porous structure of the diatomite in the ceramic filter element and reduce the antibacterial and water purification performances.
CN103382127A discloses a composite ceramic filter element and a preparation method thereof, wherein the preparation method comprises the following steps: uniformly mixing the materials, carrying out vacuum pugging, carrying out press forming, aging and standing for 4-6 hours, sending the mixture into a tunnel type sintering furnace for sintering treatment, sintering the mixture for 2-3 hours at the temperature of 420-450 ℃, heating the mixture to the temperature of 650-680 ℃ at the speed of 6-8 ℃/min for sintering for 2-3 hours, heating the mixture to the temperature of 1050-1080 ℃ at the speed of 10-12 ℃/min for sintering for 3-4 hours, taking out the mixture for cooling, sending the mixture into a 3-4% hydrochloric acid solution for soaking for 3-4 hours, then sending the mixture into a 400-450ppm potassium permanganate solution for soaking for 2-3 hours, and taking out and drying the mixture to obtain the catalyst. The preparation method not only adopts the process of firstly preparing the blank and then sintering and forming, the sintering temperature is up to 1050-; in addition, the prepared ceramic filter element contains components such as zeolite powder and the like, and inevitably contains heavy metals which are unfavorable to human health, such as copper, lead, hexavalent chromium and the like, so that the use of the ceramic filter element is greatly limited, and the ceramic filter element is not favorable for large-scale popularization and use.
CN104043288A discloses a nano-silver diatomite antibacterial filter element and a preparation method thereof, wherein the preparation method comprises the following steps: sequentially purifying and carrying out silver loading treatment on diatomite, weighing, mixing and grinding the raw materials according to a proportion, mixing the raw materials by using a liquid phase raw material, ageing for 4-6 hours, die-casting or extruding the raw material into a filter element blank, drying and sintering the filter element blank. The preparation method adopts a process of firstly preparing blank and then sintering and forming, the sintering temperature is up to 1050 ℃, so that the prepared ceramic filter core has low compressive strength, the porous structure of diatomite in the ceramic filter core can be seriously damaged, and the antibacterial and water purification performances are reduced.
In summary, there is a need to develop a novel preparation method of silver-loaded diatom shell antibacterial ceramic filter element, which can improve the compressive strength of the ceramic filter element while ensuring the porous structure.
Disclosure of Invention
In view of the problems in the prior art, the invention provides a preparation method of a silver-loaded diatom shell antibacterial ceramic filter element, which comprises the steps of sequentially mixing, grinding, liquid-phase mixing and drying raw material particles containing silver-loaded diatom shells, and then carrying out hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element. The preparation method adopts the hot-pressing sintering treatment of simultaneous pressing and sintering, and compared with the process of firstly preparing blank and then sintering and molding in the prior art, the preparation method can reduce the sintering temperature, not only can ensure that the porous structure of the silver-loaded diatom shell is not damaged, but also can greatly reduce the sintering temperatureThe compressive strength of the ceramic filter element is improved; moreover, the nano-silver loading capacity of the prepared silver-loaded diatom shell antibacterial ceramic filter element is 0.15-0.4%, the filter element has excellent adsorption performance, the filtering precision is as high as 10-100 mu m, and the specific surface area can reach 65m2The water quality safety ceramic filter element has the advantages of sterilizing and inactivating, ensuring the water quality safety of domestic water, prolonging the service life of the ceramic filter element and further increasing the market competitiveness of products.
In order to achieve the purpose, the invention adopts the following technical scheme:
one of the purposes of the invention is to provide a preparation method of a silver-loaded diatom shell antibacterial ceramic filter element, which comprises the following steps:
(1) mixing and grinding the raw material particles with the target mass ratio to obtain mixed powder; wherein the raw material particles comprise silver-loaded diatom shells;
(2) carrying out liquid-phase mixing and drying on the mixed powder obtained in the step (1);
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a mould, sealing, and then carrying out hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
Different from the prior art in which a blank is firstly made and then sintered and molded, the preparation method adopts the hot-pressing sintering treatment which is carried out simultaneously by pressing and sintering, so that the sintering temperature is lower, the porous structure of the silver-loaded diatom shell can be ensured not to be damaged, and the compressive strength of the ceramic filter element can be greatly improved; moreover, the prepared silver-loaded diatom shell antibacterial ceramic filter element not only contains silver-loaded diatom shells loaded with nano-silver particles, has excellent antibacterial performance, can ensure the water quality safety of domestic water, avoids the harm of harmful heavy metal ions and microorganisms to human bodies, but also has excellent adsorption performance, high filtering precision of 10-100 mu m and specific surface area of 65m2The steel has the advantages of obvious corrosion resistance effect, long service life and the like, and the market competitiveness of the product is further enhanced.
With ceramic filter core adoption diatomaceous earth difference among the prior art, this application ceramic filter core adopts the diatom shell, has following advantage:
1) the diatom shells have a complete multi-stage pore structure, the porosity is as high as 80-90%, and the specific surface area is 160m2The specific surface area is about 5-10 times of that of the diatomite, so that the nano-silver loading capacity of the silver-loaded diatom shell is far higher than that of the silver-loaded diatomite, and the silver-loaded diatom shell has a more excellent antibacterial effect;
2) SiO of diatom shell2Content (wt.)>95% and SiO of diatomaceous earth2The content is 60-80%, and the high cost for purifying the diatomite limits the application of the diatomite in the field of ceramic filter elements;
3) alkali metal oxides (e.g. Na) commonly found inside diatomaceous earth2O and K2O) the sintering temperature is obviously reduced during sintering, the internal multi-stage pore structure is damaged, the common muscovite sheet in the diatomite blocks the micro-nano pore structure, and the nano silver loading capacity of the diatomite is reduced;
4) the diatomite belongs to non-renewable natural resources, and the diatom shells are completely cultured artificially, so that the diatomite has the advantages of inexhaustibility and inexhaustibility, and meets the ecological requirements of environmental protection.
As a preferable technical scheme of the invention, the raw material particles in the step (1) comprise the following components in percentage by mass: 85 to 90%, for example, 85%, 86%, 87%, 88%, 89%, or 90% of silver-loaded frustules, 4 to 10%, for example, 4%, 5%, 6%, 7%, 8%, 9%, or 10% of pore-forming agents, 2 to 5%, for example, 2%, 3%, 4%, or 5% of sintering aids, and 2 to 5%, for example, 2%, 3%, 4%, or 5% of binders, but the invention is not limited to the recited values, and other values within the above-mentioned range of values are also applicable.
Preferably, the porogens comprise any one or a combination of at least two of carbon powder, starch, cellulose or calcium carbonate, typical but non-limiting examples of which are: a combination of carbon powder and starch, a combination of starch and cellulose, a combination of cellulose and calcium carbonate, a combination of carbon powder and calcium carbonate, or the like.
Preferably, the sintering aid comprises any one of alumina powder, bentonite, quartzite or potassium chloride or a combination of at least two of these, typical but non-limiting examples being: a combination of alumina powder and bentonite, a combination of bentonite and quartz clay, a combination of quartz clay and potassium chloride, a combination of alumina powder and potassium chloride, or the like.
Preferably, the adhesive comprises any one of, or a combination of at least two of, hydroxymethylcellulose, polyvinyl alcohol or polyethylene glycol, typical but non-limiting examples of which are: a combination of hydroxymethylcellulose and polyvinyl alcohol, a combination of polyvinyl alcohol and polyethylene glycol, a combination of hydroxymethylcellulose and polyethylene glycol, or the like.
As a preferable technical scheme of the invention, the preparation method of the silver-loaded frustules in the step (1) comprises the following steps: and (3) sequentially carrying out acid washing, calcining, silver-carrying treatment and secondary calcining on the frustules.
The preparation principle of the silver-loaded diatom shell is as follows: the silicon hydroxyl Si-OH on the surface of the diatom shell micropore-mesoporous structure is beneficial to Ag+Attachment to the surface of the substrate is carried out by silver-carrying treatment under alkaline conditions3)2]+Or AgOH is attached to the surface of the pore structure and then is converted into nano silver through roasting, so that the inactivation of microorganisms attached to the surface of the frustules is realized, the water purification effect of the ceramic filter element is improved, and the service life of the ceramic filter element is prolonged.
Preferably, the pickling step includes soaking the frustules in a hydrochloric acid solution or a sulfuric acid solution with a mass concentration of 5-10% for 2-4 hours, washing the filtered frustules with water until the pH value is 6.5-7.5, and drying the frustules at 70-90 ℃ for 1.5-2.5 hours, wherein specific selection of the process parameters can be reasonably selected by a person skilled in the art according to actual conditions.
Preferably, the calcination is carried out in an air atmosphere at 580-620 ℃ for 1.5-2.5 h, organic matters remained in the frustules can be effectively removed, and a person skilled in the art can reasonably select the specific selection of the process parameters according to actual conditions.
Preferably, the silver-carrying treatment is to soak calcined diatom shells in silver nitrate solution for 0.5-1 h, and then mechanically stir for 1.8-2.2 h, so that A can be realizedg+Uniformly distributing on the inner wall of the micropore-mesopore of the frustules, then dropwise adding an ammonia water solution with the mass concentration of 0.8-1.2% until the ammonia water solution is excessive, standing for 1-2 h, washing the filtered frustules with clear water, and drying at 70-90 ℃ for 1.5-2.5 h.
Preferably, the amount of silver nitrate in the silver nitrate solution is 0.1 to 0.4% by mass of the calcined frustules, for example, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4% or the like, but is not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the silver nitrate solution has a concentration of 0.5 to 1g/L, such as 0.5g/L, 0.6g/L, 0.7g/L, 0.8g/L, 0.9g/L, or 1g/L, but not limited to the recited values, and other values not recited within the range of values are equally applicable.
Preferably, the secondary calcination is carried out for 1.5-2.5 hours in an air atmosphere at 500-600 ℃, and for the specific selection of the process parameters, a person skilled in the art can reasonably select the secondary calcination according to actual conditions.
As a preferred technical scheme of the invention, the grinding in the step (1) is ball milling.
Preferably, the rotation speed of the ball mill is 250-350 rpm, such as 250rpm, 270rpm, 290rpm, 300rpm, 320rpm, 340rpm or 350rpm, but not limited to the enumerated values, and other unrecited values in the numerical range are also applicable.
Preferably, the ball milling time is 1.5 to 2 hours, such as 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, 2 hours, etc., but not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the particle size of the powder mixture in step (1) is less than 45 μm, and can be reasonably selected by one skilled in the art according to actual conditions.
In a preferred embodiment of the present invention, the liquid phase used in the liquid phase kneading in step (2) is polyvinyl alcohol and water.
Preferably, the amount of polyvinyl alcohol used in the liquid-phase kneading in step (2) is 10 to 13% by mass, for example, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, or 13% by mass of the silver-loaded frustules, but is not limited to the recited values, and other values not recited in the above range are also applicable.
Preferably, the amount of water used in the liquid-phase mixing in step (2) is 13 to 16% by mass of the silver-loaded frustules, for example 13%, 13.5%, 14%, 14.5%, 15%, 15.5% or 16% by mass, but is not limited to the recited values, and other values not recited in the range of the recited values are also applicable.
In a preferred embodiment of the present invention, the time for the liquid-phase kneading in step (2) is 2 to 3 hours, for example, 2 hours, 2.2 hours, 2.4 hours, 2.5 hours, 2.6 hours, 2.8 hours, or 3 hours, but the liquid-phase kneading is not limited to the above-mentioned values, and other values not shown in the above-mentioned range of values are also applicable.
Preferably, the drying temperature in step (2) is 80 to 120 ℃, for example 80 ℃, 90 ℃, 100 ℃, 110 ℃ or 120 ℃, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the drying time in step (2) is 1.5-2.5 h, such as 1.5h, 1.7h, 1.9h, 2h, 2.3h or 2.5h, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
As a preferable technical scheme of the invention, the mould in the step (3) is a graphite mould.
Preferably, before the hot-pressing sintering in the step (3), sintering pretreatment is carried out on the sealed die.
Preferably, the pressure of the pretreatment is 10 to 30MPa, for example, 10MPa, 15MPa, 20MPa, 25MPa, or 30MPa, but is not limited to the recited values, and other values not recited within the range of the recited values are also applicable.
Preferably, the hot-pressing sintering in the step (3) is carried out at a heating rate of 4-6 ℃/min until the temperature is raised to 600-800 ℃.
The heating rate of the hot-pressing sintering is 4-6 ℃/min, such as 4 ℃/min, 4.3 ℃/min, 4.5 ℃/min, 4.8 ℃/min, 5 ℃/min, 5.5 ℃/min, or 6 ℃/min, but is not limited to the values listed, and other values not listed within the range of the values are also applicable.
The temperature of the hot press sintering is 600 to 800 ℃, for example 600 ℃, 620 ℃, 650 ℃, 670 ℃, 700 ℃, 720 ℃, 750 ℃, 770 ℃ or 800 ℃, but is not limited to the values listed, and other values not listed in the numerical range are also applicable.
Preferably, the pressure of the hot press sintering in step (3) is 10 to 20MPa, for example, 10MPa, 12MPa, 14MPa, 15MPa, 17MPa, 19MPa or 20MPa, but not limited to the values listed, and other values not listed in the range of the values are also applicable.
Preferably, the holding and pressure maintaining time of the hot pressing sintering in the step (3) is 2 to 4 hours, such as 2 hours, 2.2 hours, 2.5 hours, 2.7 hours, 3 hours, 3.3 hours, 3.5 hours, 3.8 hours or 4 hours, but not limited to the recited values, and other values not recited in the range of the values are also applicable.
Preferably, the hot press sintering of step (3) is performed under vacuum.
Preferably, the hot-pressing sintering of step (3) is performed in a hot-pressing sintering furnace.
The hot-pressing sintering of the invention is that dry powder is filled into a mould and then placed in a hot-pressing sintering furnace, and the mould is pressurized and heated from the uniaxial direction under the vacuum condition, so that the powder generates plastic deformation in the pressing process, the atoms of the pressed compact obtain diffusion activation energy, the migration rate of the crystal boundary is accelerated, and the high-density ceramic filter element is obtained; moreover, the hot-pressing sintering process is designed aiming at the performance of the mixed powder containing the silver-loaded diatom shells, the sintering pretreatment with the pressure of 10-30 MPa can effectively enable the mixed powder to reach the density required by the subsequent hot-pressing sintering, prevent cracks or internal defects from occurring in the subsequent hot-pressing sintering process, further limit the heating rate, temperature, pressure and heat-preservation and pressure-maintaining time of the hot-pressing sintering, not only ensure that the porous structure of the silver-loaded diatom shells is not damaged, but also greatly improve the compressive strength of the ceramic filter element.
As a preferable technical scheme of the invention, the step (3) of hot-pressing sintering further comprises polishing treatment, so as to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
As a preferred technical scheme of the invention, the preparation method comprises the following steps:
(1) according to the mass percentage, raw material particles comprising 85-90% of silver-loaded diatom shells, 4-10% of pore-forming agent, 2-5% of sintering aid and 2-5% of adhesive are mixed, and then ball-milled for 1.5-2 hours at the rotating speed of 250-350 rpm to obtain mixed powder with the particle size of less than 45 microns;
the preparation method of the silver-loaded diatom shells comprises the following steps: pickling, calcining, silver-carrying treatment and secondary calcining are carried out on the frustules in sequence;
(2) mixing the mixed powder obtained in the step (1) in a liquid phase in polyvinyl alcohol and water for 2-3 h, wherein the using amount of the polyvinyl alcohol is 10-13% of the mass of the silver-loaded frustules, the using amount of the water is 13-16% of the mass of the silver-loaded frustules, and then drying for 1.5-2.5 h at the temperature of 80-120 ℃;
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a graphite mold, sealing, then putting into a hot-pressing sintering furnace, sintering the sealed mold at 10-30 MPa for pretreatment, heating to 600-800 ℃ at a heating rate of 4-6 ℃/min, controlling the pressure to 10-20 MPa for hot-pressing sintering, keeping the temperature and pressure for 2-4 h under a vacuum condition, cooling the hot-pressing sintering furnace to room temperature, and polishing the ceramic filter element subjected to hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
The preparation method prepares the silver-loaded diatom shell antibacterial ceramic filter element by hot-pressing sintering, can increase the compressive strength of the porous ceramic filter element, prolong the service life of the filter element, and can keep the original complex pore structure in the silver-loaded diatom shell, thereby efficiently removing harmful heavy metal ions, organic matters and microorganisms in drinking water.
The second purpose of the invention is to provide a silver-loaded diatom shell antibacterial ceramic filter element which is prepared by the preparation method of the first purpose.
Preferably, the silver-loaded diatom shell antibacterial ceramic filter element has a nano silver loading of 0.15-0.4%, such as 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, or 0.4%, but not limited to the recited values, and other values not recited in this range are also applicable.
Compared with the prior art, the invention has at least the following beneficial effects:
(1) the preparation method adopts the hot-pressing sintering treatment of simultaneous pressing and sintering, so that the sintering temperature is lower, the porous structure of the silver-loaded diatom shell can be ensured not to be damaged, and the compressive strength of the ceramic filter element can be greatly improved;
(2) the silver-loaded diatom shell antibacterial ceramic filter element obtained by the preparation method not only contains silver-loaded diatom shells loaded with nano-silver particles, the nano-silver loading amount is 0.15-0.4%, and the filter element has excellent antibacterial performance, can ensure the water quality safety of domestic water, avoid the harm of harmful heavy metal ions and microorganisms to human bodies, but also has excellent adsorption performance, the filtering precision is as high as 10-100 mu m, and the specific surface area can reach 65m2The steel has the advantages of obvious corrosion resistance effect, long service life and the like, and the market competitiveness of the product is further enhanced.
Detailed Description
For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.
Example 1
The embodiment provides a preparation method of a silver-loaded diatom shell antibacterial ceramic filter element, which comprises the following steps:
(1) weighing 90% of silver-loaded diatom shells, 4% of carbon powder serving as a pore-forming agent, 4% of alumina powder serving as a sintering aid and 2% of hydroxymethyl cellulose serving as an adhesive according to the mass percentage, mixing, and then carrying out ball milling for 2 hours at the rotating speed of 300rpm to obtain mixed powder with the particle size of less than 45 microns;
the preparation method of the silver-loaded diatom shells comprises the following steps: firstly, soaking diatom shells produced by Shenzhen Taili energy company in a hydrochloric acid solution with the mass concentration of 5% for 3h, then washing the filtered diatom shells with water until the pH value is 6.5-7.5, and then drying for 2h at 70 ℃; then calcining for 2h in an air atmosphere at 600 ℃; soaking the calcined diatom ootheca in a silver nitrate solution with the concentration of 0.7g/L for 1 hour, wherein the using amount of silver nitrate is 0.4 percent of the mass of the calcined diatom ootheca, then mechanically stirring for 2 hours, dropwise adding an ammonia water solution with the mass concentration of 1 percent until the ammonia water solution is excessive, standing for 2 hours, washing the filtered diatom ootheca with clear water, and drying for 2 hours at the temperature of 80 ℃ to finish the silver-carrying treatment; finally, calcining for 2 hours in the air atmosphere at the temperature of 600 ℃ for the second time to obtain the silver-loaded diatom shell;
(2) mixing the mixed powder obtained in the step (1) in a liquid phase in polyvinyl alcohol and water for 2.5 hours, wherein the using amount of the polyvinyl alcohol is 12% of the mass of the silver-loaded frustules, and the using amount of the water is 15% of the mass of the silver-loaded frustules, and then drying for 2 hours at 100 ℃;
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a graphite mold, sealing, then putting into a hot-pressing sintering furnace, sintering the sealed mold under 20MPa for pretreatment, heating to 800 ℃ at a heating rate of 5 ℃/min, controlling the pressure to be 15MPa for hot-pressing sintering, keeping the temperature and pressure for 3 hours under a vacuum condition, then cooling the hot-pressing sintering furnace to room temperature, and polishing the ceramic filter element subjected to hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
Example 2
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, except that the temperature of the hot-press sintering in step (3) is changed from "800 ℃ to" 900 ℃, and the other conditions are exactly the same as in example 1.
Example 3
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, except that the temperature of the hot-press sintering in step (3) is changed from "800 ℃ to" 500 ℃, and the other conditions are exactly the same as in example 1.
Example 4
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, which is identical to that of example 1 except that the pressure of the hot-pressing sintering in step (3) is changed from "15 MPa" to "8 MPa".
Example 5
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, which is identical to that of example 1 except that the pressure of the hot-pressing sintering in step (3) is changed from "15 MPa" to "22 MPa".
Example 6
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, which is identical to that of example 1 except that the heating rate of the hot-pressing sintering in step (3) is changed from "5 ℃/min" to "3 ℃/min".
Example 7
This example provides a method for preparing a silver-loaded diatom shell antibacterial ceramic filter element, which is identical to that of example 1 except that the heating rate of the hot-pressing sintering in step (3) is changed from "5 ℃/min" to "7 ℃/min".
Example 8
The embodiment provides a preparation method of a silver-loaded diatom shell antibacterial ceramic filter element, which comprises the following steps:
(1) weighing 88% of silver-loaded diatom shells, 4% of calcium carbonate serving as a pore-forming agent, 3% of potassium chloride serving as a sintering aid and 5% of polyvinyl alcohol serving as an adhesive according to the mass percentage, mixing the raw material particles, and then carrying out ball milling for 1.5h at the rotating speed of 350rpm to obtain mixed powder with the particle size less than 45 microns;
the preparation method of the silver-loaded diatom shells comprises the following steps: firstly, soaking diatom shells produced by Shenzhen Taili energy company in a hydrochloric acid solution with the mass concentration of 10% for 2 hours, then washing the filtered diatom shells with water until the pH value is 6.5-7.5, and then drying for 2.5 hours at 70 ℃; then calcining for 1.5h in an air atmosphere at 620 ℃; soaking the calcined diatom ootheca in a silver nitrate solution with the concentration of 1g/L for 0.5h, wherein the using amount of silver nitrate is 0.4% of the mass of the calcined diatom ootheca, then mechanically stirring for 2.2h, dropwise adding an ammonia water solution with the mass concentration of 1% until the ammonia water solution is excessive, standing for 1h, washing the filtered diatom ootheca with clear water, and drying at 90 ℃ for 1.5h to finish silver-carrying treatment; finally, calcining for 2.5h in the air atmosphere at 500 ℃ for the second time to obtain the silver-loaded diatom shell;
(2) mixing the mixed powder obtained in the step (1) in a liquid phase in polyvinyl alcohol and water for 3 hours, wherein the using amount of the polyvinyl alcohol is 10% of the mass of the silver-loaded frustules, and the using amount of the water is 13% of the mass of the silver-loaded frustules, and then drying for 1.5 hours at 120 ℃;
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a graphite mold, sealing, then putting into a hot-pressing sintering furnace, sintering the sealed mold at 30MPa for pretreatment, heating to 800 ℃ at a heating rate of 5 ℃/min, controlling the pressure to be 15MPa for hot-pressing sintering, keeping the temperature and pressure for 3 hours under a vacuum condition, cooling the hot-pressing sintering furnace to room temperature, and polishing the ceramic filter element subjected to hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
Example 9
The embodiment provides a preparation method of a silver-loaded diatom shell antibacterial ceramic filter element, which comprises the following steps:
(1) weighing 85% of silver-loaded diatom shells, 6% of starch serving as a pore-forming agent, 5% of bentonite serving as a sintering aid and 4% of polyethylene glycol serving as an adhesive according to the mass percentage, mixing, and then carrying out ball milling for 2 hours at the rotating speed of 250rpm to obtain mixed powder with the particle size of less than 45 microns;
the preparation method of the silver-loaded diatom shells comprises the following steps: firstly, soaking diatom shells produced by Shenzhen Taili energy company in a hydrochloric acid solution with the mass concentration of 10% for 2 hours, then washing the filtered diatom shells with water until the pH value is 6.5-7.5, and then drying for 1.5 hours at 90 ℃; then calcining for 2.5h in an air atmosphere at 580 ℃; soaking the calcined diatom ootheca in a silver nitrate solution with the concentration of 0.5g/L for 1 hour, wherein the using amount of silver nitrate is 0.4 percent of the mass of the calcined diatom ootheca, then mechanically stirring for 1.8 hours, dropwise adding an ammonia water solution with the mass concentration of 1 percent till the solution is excessive, standing for 2 hours, washing the filtered diatom ootheca with clear water, and drying at 70 ℃ for 2.5 hours to finish silver-carrying treatment; finally, calcining for 1.5h in the air atmosphere at 600 ℃ for the second time to obtain the silver-loaded diatom shell;
(2) mixing the mixed powder obtained in the step (1) in a liquid phase in polyvinyl alcohol and water for 2 hours, wherein the using amount of the polyvinyl alcohol is 13% of the mass of the silver-loaded frustules, and the using amount of the water is 16% of the mass of the silver-loaded frustules, and then drying for 2.5 hours at 80 ℃;
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a graphite mold, sealing, then putting into a hot-pressing sintering furnace, sintering the sealed mold at 30MPa for pretreatment, heating to 600 ℃ at a heating rate of 4 ℃/min, controlling the pressure to be 10MPa for hot-pressing sintering, keeping the temperature and pressure for 4 hours under a vacuum condition, cooling the hot-pressing sintering furnace to room temperature, and polishing the ceramic filter element subjected to hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
Comparative example 1
The silver-loaded diatom shell antibacterial ceramic filter element is prepared according to the preparation method provided in preparation example 1 of CN 104043288A.
The silver-loaded diatom shell antibacterial ceramic filter element obtained in the above examples and comparative examples is subjected to the following performance tests:
microstructure: the microstructure of the ceramic filter element is characterized by using a Tescan VEGA 3LMH scanning electron microscope;
compressive strength: an Instron-2367 universal tester is used for representing the compressive strength of the ceramic filter element;
nano silver loading: the nanometer silver loading capacity of the ceramic filter element is characterized by utilizing a PE type Atomic Absorption Spectrophotometer (AAS);
the antibacterial rate is as follows: according to a dipping oscillation method disclosed by the national standard JC/T897-2014 antibacterial ceramic product antibacterial performance, taking escherichia coli and staphylococcus aureus as test strains;
and (3) filtering precision: the method comprises the following steps of (1) representing the filtering precision of the ceramic filter element by using a PSS AccuSizer FX-Nano type particle counter;
specific surface area: the specific surface area of the ceramic filter element is characterized by utilizing an ASAP 2020plus HD88 type full-automatic specific surface area analyzer;
the results of the tests on the silver-loaded frustules antimicrobial ceramic filter elements obtained in the above examples and comparative examples are shown in table 1.
TABLE 1
From table 1, the following points can be seen:
(1) the preparation method adopts the hot-pressing sintering treatment of simultaneous pressing and sintering, and compared with the process of firstly preparing blank and then sintering for molding in the prior art, the preparation method can reduce the sintering temperature, not only can ensure that the porous structure of the silver-loaded diatom shell is not damaged, but also can greatly improve the mechanical strength and compressive strength of the ceramic filter element; moreover, the nano-silver loading capacity of the prepared silver-loaded diatom shell antibacterial ceramic filter element is 0.15-0.4%, the filter element has excellent adsorption performance, the filtering precision is as high as 10-100 micrometers, the specific surface area can reach 65m2/g, the filter element also has the effects of sterilization and inactivation, the water quality safety of domestic water is ensured, the service life of the ceramic filter element is prolonged, and the market competitiveness of products is further increased;
(2) comparing example 1 with examples 2 and 3, it can be seen that, since the hot-press sintering temperature in example 2 or 3 is not in the range of 600-800 ℃ in the present application, the compressive strength, nano-silver loading amount, filtering accuracy and specific surface area of the prepared ceramic filter element are all reduced;
(3) comparing example 1 with examples 4 and 5, it can be seen that the pressure of the hot-press sintering in example 4 is lower than 10-20 MPa described herein, which results in a decrease in the nano silver loading and the filtration precision of the ceramic filter element obtained, and the pressure of the hot-press sintering in example 5 is higher than 10-20 MPa described herein, which results in a decrease in the filtration precision and the specific surface area of the ceramic filter element obtained;
(4) comparing example 1 with examples 6 and 7, it can be seen that, since the heating rate of the hot-press sintering in example 6 or 7 is not within the range of 4-6 ℃/min, the compressive strength, the nano-silver loading amount, the filtering precision and the specific surface area of the prepared ceramic filter element are reduced;
(5) comparing example 1 with comparative example 1, it can be seen that, because the preparation process of comparative example 1, in which the blank is prepared first and then sintered and molded according to the prior art, has a high sintering temperature, and the porous structure of the frustules is seriously damaged, the microstructure of the prepared ceramic filter element is only partially intact, the compressive strength is only 25MPa, and the nano-silver loading, the antibacterial rate, the filtration precision and the specific surface area are all lower than those of example 1.
The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.
Claims (10)
1. A preparation method of a silver-loaded diatom shell antibacterial ceramic filter element is characterized by comprising the following steps:
(1) mixing and grinding the raw material particles with the target mass ratio to obtain mixed powder; wherein the raw material particles comprise silver-loaded diatom shells;
(2) carrying out liquid-phase mixing and drying on the mixed powder obtained in the step (1);
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a mould, sealing, and then carrying out hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
2. The production method according to claim 1, wherein the raw material particles in the step (1) comprise, in terms of mass percentage: 85-90% of silver-loaded diatom shells, 4-10% of pore-forming agent, 2-5% of sintering aid and 2-5% of adhesive;
preferably, the pore-forming agent comprises any one or a combination of at least two of carbon powder, starch, cellulose or calcium carbonate;
preferably, the sintering aid comprises any one or a combination of at least two of alumina powder, bentonite, quartz clay or potassium chloride;
preferably, the adhesive comprises any one of or a combination of at least two of hydroxymethyl cellulose, polyvinyl alcohol or polyethylene glycol.
3. The method according to claim 1 or 2, wherein the method for preparing the silver-loaded frustules of step (1) comprises: pickling, calcining, silver-carrying treatment and secondary calcining are carried out on the frustules in sequence;
preferably, the pickling step includes soaking the frustules in a hydrochloric acid solution or a sulfuric acid solution with a mass concentration of 5-10% for 2-4 hours, washing the filtered frustules with water until the pH value is 6.5-7.5, and drying the frustules at 70-90 ℃ for 1.5-2.5 hours;
preferably, the calcination is carried out for 1.5-2.5 h in an air atmosphere at 580-620 ℃;
preferably, the silver-carrying treatment is to soak calcined diatom shells in a silver nitrate solution for 0.5-1 h, then mechanically stir for 1.8-2.2 h, then dropwise add an ammonia water solution with the mass concentration of 0.8-1.2% until the solution is excessive, stand for 1-2 h, wash filtered diatom shells with clear water, and then dry at 70-90 ℃ for 1.5-2.5 h;
preferably, the amount of silver nitrate in the silver nitrate solution is 0.1-0.4% of the mass of the calcined diatom shell;
preferably, the concentration of the silver nitrate solution is 0.5-1 g/L;
preferably, the secondary calcination is carried out for 1.5-2.5 h in an air atmosphere at 500-600 ℃.
4. The method according to any one of claims 1 to 3, wherein the grinding in step (1) is ball milling;
preferably, the rotation speed of the ball mill is 250-350 rpm;
preferably, the ball milling time is 1.5-2 h;
preferably, the particle size of the mixed powder in the step (1) is less than 45 μm.
5. The preparation method according to any one of claims 1 to 4, wherein the liquid phase used in the liquid phase mixing in step (2) is polyvinyl alcohol and water;
preferably, the dosage of the polyvinyl alcohol in the liquid-phase mixing in the step (2) is 10-13% of the mass of the silver-loaded frustules;
preferably, the amount of water used in the liquid-phase mixing in the step (2) is 13-16% of the mass of the silver-loaded frustules.
6. The process according to any one of claims 1 to 5, wherein the liquid-phase kneading in step (2) is carried out for 2 to 3 hours;
preferably, the drying temperature in the step (2) is 80-120 ℃;
preferably, the drying time in the step (2) is 1.5-2.5 h.
7. The method according to any one of claims 1 to 6, wherein the mold in the step (3) is a graphite mold;
preferably, before the hot-pressing sintering in the step (3), sintering pretreatment is carried out on the sealed die;
preferably, the pressure of the pretreatment is 10-30 MPa;
preferably, the hot-pressing sintering in the step (3) is carried out, and the temperature is increased to 600-800 ℃ at the heating rate of 4-6 ℃/min;
preferably, the pressure of the hot-pressing sintering in the step (3) is 10-20 MPa;
preferably, the heat preservation and pressure maintaining time of the hot-pressing sintering in the step (3) is 2-4 h;
preferably, the hot-press sintering of step (3) is performed under vacuum conditions;
preferably, the hot-pressing sintering of step (3) is performed in a hot-pressing sintering furnace.
8. The preparation method according to any one of claims 1 to 7, wherein the step (3) further comprises polishing after hot-pressing sintering, so as to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
9. The method according to any one of claims 1 to 8, characterized by comprising the steps of:
(1) according to the mass percentage, raw material particles comprising 85-90% of silver-loaded diatom shells, 4-10% of pore-forming agent, 2-5% of sintering aid and 2-5% of adhesive are mixed, and then ball-milled for 1.5-2 hours at the rotating speed of 250-350 rpm to obtain mixed powder with the particle size of less than 45 microns;
the preparation method of the silver-loaded diatom shells comprises the following steps: pickling, calcining, silver-carrying treatment and secondary calcining are carried out on the frustules in sequence;
(2) mixing the mixed powder obtained in the step (1) in a liquid phase in polyvinyl alcohol and water for 2-3 h, wherein the using amount of the polyvinyl alcohol is 10-13% of the mass of the silver-loaded frustules, the using amount of the water is 13-16% of the mass of the silver-loaded frustules, and then drying for 1.5-2.5 h at the temperature of 80-120 ℃;
(3) and (3) filling the mixed powder obtained by the treatment in the step (2) into a graphite mold, sealing, then putting into a hot-pressing sintering furnace, sintering the sealed mold at 10-30 MPa for pretreatment, heating to 600-800 ℃ at a heating rate of 4-6 ℃/min, controlling the pressure to 10-20 MPa for hot-pressing sintering, keeping the temperature and pressure for 2-4 h under a vacuum condition, cooling the hot-pressing sintering furnace to room temperature, and polishing the ceramic filter element subjected to hot-pressing sintering to obtain the silver-loaded diatom shell antibacterial ceramic filter element.
10. An antibacterial ceramic filter element of silver-loaded diatom shells, which is characterized by being prepared by the preparation method of any one of claims 1-9;
preferably, the nano-silver loading capacity of the silver-loaded diatom shell antibacterial ceramic filter element is 0.15-0.4%.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114229856A (en) * | 2022-01-19 | 2022-03-25 | 中南大学 | Method for extracting diatom shells |
| CN114573331A (en) * | 2022-03-16 | 2022-06-03 | 佛山市芯耀环保科技有限公司 | Antibacterial scale-inhibiting ceramic material and preparation method and application thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103071400A (en) * | 2013-01-05 | 2013-05-01 | 宁波爱去欧净水设备科技有限公司 | Manufacturing method of microporous membrane sinter filter element |
| CN103381318A (en) * | 2013-06-25 | 2013-11-06 | 蚌埠凤凰滤清器有限责任公司 | Micropore nano-silver active filter core and preparation method thereof |
| CN104043288A (en) * | 2014-05-20 | 2014-09-17 | 浙江朝晖过滤技术股份有限公司 | Nnano-silver diatomite antibacterial filter core and preparation method thereof |
| CN105854415A (en) * | 2016-04-20 | 2016-08-17 | 潘能红 | Compound sintered filtering core for water purifier and preparing method of compound sintered filtering core |
| CN107261645A (en) * | 2017-07-03 | 2017-10-20 | 中国地质大学（武汉） | A kind of method for cooking of the complex sintered active carbon filter core of antibacterial zeolite particles |
| CN107602101A (en) * | 2017-08-10 | 2018-01-19 | 东莞市倍益清环保科技有限公司 | A kind of ceramic element of Efficient antibacterial and preparation method thereof |
| CN107619279A (en) * | 2017-09-01 | 2018-01-23 | 威海文润测控设备有限公司 | A kind of carbon nanometer high-temperature ceramic and preparation method thereof |
| CN109250781A (en) * | 2018-09-30 | 2019-01-22 | 江苏斯沃得环保科技有限公司 | A kind of preparation method of sintering activity charcoal water purification catridge |
-
2020
- 2020-08-14 CN CN202010819463.6A patent/CN111943717A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103071400A (en) * | 2013-01-05 | 2013-05-01 | 宁波爱去欧净水设备科技有限公司 | Manufacturing method of microporous membrane sinter filter element |
| CN103381318A (en) * | 2013-06-25 | 2013-11-06 | 蚌埠凤凰滤清器有限责任公司 | Micropore nano-silver active filter core and preparation method thereof |
| CN104043288A (en) * | 2014-05-20 | 2014-09-17 | 浙江朝晖过滤技术股份有限公司 | Nnano-silver diatomite antibacterial filter core and preparation method thereof |
| CN105854415A (en) * | 2016-04-20 | 2016-08-17 | 潘能红 | Compound sintered filtering core for water purifier and preparing method of compound sintered filtering core |
| CN107261645A (en) * | 2017-07-03 | 2017-10-20 | 中国地质大学（武汉） | A kind of method for cooking of the complex sintered active carbon filter core of antibacterial zeolite particles |
| CN107602101A (en) * | 2017-08-10 | 2018-01-19 | 东莞市倍益清环保科技有限公司 | A kind of ceramic element of Efficient antibacterial and preparation method thereof |
| CN107619279A (en) * | 2017-09-01 | 2018-01-23 | 威海文润测控设备有限公司 | A kind of carbon nanometer high-temperature ceramic and preparation method thereof |
| CN109250781A (en) * | 2018-09-30 | 2019-01-22 | 江苏斯沃得环保科技有限公司 | A kind of preparation method of sintering activity charcoal water purification catridge |
Non-Patent Citations (1)
| Title |
|---|
| 李恒德: "《现代材料科学与工程辞典》", 31 August 2001, 山东科学技术出版社 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114229856A (en) * | 2022-01-19 | 2022-03-25 | 中南大学 | Method for extracting diatom shells |
| CN114573331A (en) * | 2022-03-16 | 2022-06-03 | 佛山市芯耀环保科技有限公司 | Antibacterial scale-inhibiting ceramic material and preparation method and application thereof |
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