CN112661493B - Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane - Google Patents
Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane Download PDFInfo
- Publication number
- CN112661493B CN112661493B CN201910985134.6A CN201910985134A CN112661493B CN 112661493 B CN112661493 B CN 112661493B CN 201910985134 A CN201910985134 A CN 201910985134A CN 112661493 B CN112661493 B CN 112661493B
- Authority
- CN
- China
- Prior art keywords
- fly ash
- support
- content
- ceramic membrane
- composition
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 239000010881 fly ash Substances 0.000 title claims abstract description 291
- 239000000919 ceramic Substances 0.000 title claims abstract description 112
- 239000012528 membrane Substances 0.000 title claims abstract description 106
- 238000002360 preparation method Methods 0.000 title claims abstract description 9
- 238000002715 modification method Methods 0.000 title description 3
- 238000000034 method Methods 0.000 claims abstract description 75
- 239000000203 mixture Substances 0.000 claims abstract description 56
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 32
- 239000011148 porous material Substances 0.000 claims abstract description 32
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 28
- 239000004014 plasticizer Substances 0.000 claims abstract description 24
- 229910010413 TiO 2 Inorganic materials 0.000 claims abstract description 21
- 150000004676 glycans Chemical class 0.000 claims abstract description 17
- 229920001282 polysaccharide Polymers 0.000 claims abstract description 17
- 239000005017 polysaccharide Substances 0.000 claims abstract description 17
- 238000005452 bending Methods 0.000 claims abstract description 16
- 239000011159 matrix material Substances 0.000 claims abstract description 15
- 230000004907 flux Effects 0.000 claims abstract description 14
- 239000002253 acid Substances 0.000 claims abstract description 10
- 239000003513 alkali Substances 0.000 claims abstract description 10
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 claims description 29
- 239000011248 coating agent Substances 0.000 claims description 25
- 238000000576 coating method Methods 0.000 claims description 25
- 238000000465 moulding Methods 0.000 claims description 23
- 239000007788 liquid Substances 0.000 claims description 19
- 229920001661 Chitosan Polymers 0.000 claims description 16
- 229920002401 polyacrylamide Polymers 0.000 claims description 16
- 239000010865 sewage Substances 0.000 claims description 13
- 238000001125 extrusion Methods 0.000 claims description 12
- 235000011187 glycerol Nutrition 0.000 claims description 10
- 230000007797 corrosion Effects 0.000 claims description 9
- 238000005260 corrosion Methods 0.000 claims description 9
- 229920002134 Carboxymethyl cellulose Polymers 0.000 claims description 8
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 8
- 239000001768 carboxy methyl cellulose Substances 0.000 claims description 8
- 235000010948 carboxy methyl cellulose Nutrition 0.000 claims description 8
- 239000008112 carboxymethyl-cellulose Substances 0.000 claims description 8
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 8
- 238000010304 firing Methods 0.000 claims description 7
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 claims description 6
- 229920002678 cellulose Polymers 0.000 claims description 6
- 239000001913 cellulose Substances 0.000 claims description 6
- 229920000609 methyl cellulose Polymers 0.000 claims description 6
- 239000001923 methylcellulose Substances 0.000 claims description 6
- 235000010981 methylcellulose Nutrition 0.000 claims description 6
- 239000004071 soot Substances 0.000 claims description 6
- 238000002156 mixing Methods 0.000 claims description 5
- 238000005245 sintering Methods 0.000 claims description 4
- 239000002202 Polyethylene glycol Substances 0.000 claims description 3
- 229920001223 polyethylene glycol Polymers 0.000 claims description 3
- 235000019422 polyvinyl alcohol Nutrition 0.000 claims description 3
- 238000007493 shaping process Methods 0.000 claims description 3
- 229920002101 Chitin Polymers 0.000 claims description 2
- 239000001866 hydroxypropyl methyl cellulose Substances 0.000 claims description 2
- 229920003088 hydroxypropyl methyl cellulose Polymers 0.000 claims description 2
- 235000010979 hydroxypropyl methyl cellulose Nutrition 0.000 claims description 2
- UFVKGYZPFZQRLF-UHFFFAOYSA-N hydroxypropyl methyl cellulose Chemical compound OC1C(O)C(OC)OC(CO)C1OC1C(O)C(O)C(OC2C(C(O)C(OC3C(C(O)C(O)C(CO)O3)O)C(CO)O2)O)C(CO)O1 UFVKGYZPFZQRLF-UHFFFAOYSA-N 0.000 claims description 2
- 238000000748 compression moulding Methods 0.000 claims 4
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 claims 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 claims 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 claims 1
- 239000005642 Oleic acid Substances 0.000 claims 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 claims 1
- 239000004359 castor oil Substances 0.000 claims 1
- 235000019438 castor oil Nutrition 0.000 claims 1
- 238000007906 compression Methods 0.000 claims 1
- 230000006835 compression Effects 0.000 claims 1
- ZEMPKEQAKRGZGQ-XOQCFJPHSA-N glycerol triricinoleate Natural products CCCCCC[C@@H](O)CC=CCCCCCCCC(=O)OC[C@@H](COC(=O)CCCCCCCC=CC[C@@H](O)CCCCCC)OC(=O)CCCCCCCC=CC[C@H](O)CCCCCC ZEMPKEQAKRGZGQ-XOQCFJPHSA-N 0.000 claims 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 claims 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 claims 1
- 235000021313 oleic acid Nutrition 0.000 claims 1
- 239000003549 soybean oil Substances 0.000 claims 1
- 235000012424 soybean oil Nutrition 0.000 claims 1
- 239000002383 tung oil Substances 0.000 claims 1
- 239000002245 particle Substances 0.000 abstract description 27
- 230000000903 blocking effect Effects 0.000 abstract description 2
- 230000035515 penetration Effects 0.000 abstract description 2
- 239000010883 coal ash Substances 0.000 description 20
- 230000000704 physical effect Effects 0.000 description 14
- 230000007547 defect Effects 0.000 description 13
- 238000010438 heat treatment Methods 0.000 description 13
- 238000005470 impregnation Methods 0.000 description 9
- 239000002518 antifoaming agent Substances 0.000 description 8
- 238000010998 test method Methods 0.000 description 8
- 239000003755 preservative agent Substances 0.000 description 7
- 230000002335 preservative effect Effects 0.000 description 7
- 239000002994 raw material Substances 0.000 description 7
- 230000032683 aging Effects 0.000 description 6
- 239000004721 Polyphenylene oxide Substances 0.000 description 5
- 229920000570 polyether Polymers 0.000 description 5
- 238000007670 refining Methods 0.000 description 5
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 description 4
- 239000003245 coal Substances 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000843 powder Substances 0.000 description 4
- 238000005507 spraying Methods 0.000 description 4
- 239000013530 defoamer Substances 0.000 description 3
- 238000007598 dipping method Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 238000001878 scanning electron micrograph Methods 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- CHHHXKFHOYLYRE-UHFFFAOYSA-M 2,4-Hexadienoic acid, potassium salt (1:1), (2E,4E)- Chemical compound [K+].CC=CC=CC([O-])=O CHHHXKFHOYLYRE-UHFFFAOYSA-M 0.000 description 2
- 239000005711 Benzoic acid Substances 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 235000010233 benzoic acid Nutrition 0.000 description 2
- 239000002440 industrial waste Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000012982 microporous membrane Substances 0.000 description 2
- 239000003607 modifier Substances 0.000 description 2
- 239000012466 permeate Substances 0.000 description 2
- 235000010241 potassium sorbate Nutrition 0.000 description 2
- 239000004302 potassium sorbate Substances 0.000 description 2
- 229940069338 potassium sorbate Drugs 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 238000000926 separation method Methods 0.000 description 2
- WXMKPNITSTVMEF-UHFFFAOYSA-M sodium benzoate Chemical compound [Na+].[O-]C(=O)C1=CC=CC=C1 WXMKPNITSTVMEF-UHFFFAOYSA-M 0.000 description 2
- 235000010234 sodium benzoate Nutrition 0.000 description 2
- 239000004299 sodium benzoate Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 239000004113 Sepiolite Substances 0.000 description 1
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 229920002472 Starch Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000008367 deionised water Substances 0.000 description 1
- 229910021641 deionized water Inorganic materials 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- GUJOJGAPFQRJSV-UHFFFAOYSA-N dialuminum;dioxosilane;oxygen(2-);hydrate Chemical compound O.[O-2].[O-2].[O-2].[Al+3].[Al+3].O=[Si]=O.O=[Si]=O.O=[Si]=O.O=[Si]=O GUJOJGAPFQRJSV-UHFFFAOYSA-N 0.000 description 1
- 239000006185 dispersion Substances 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- RBNPOMFGQQGHHO-UHFFFAOYSA-N glyceric acid Chemical compound OCC(O)C(O)=O RBNPOMFGQQGHHO-UHFFFAOYSA-N 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 229910052900 illite Inorganic materials 0.000 description 1
- 229910052500 inorganic mineral Inorganic materials 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 229910052622 kaolinite Inorganic materials 0.000 description 1
- 239000011707 mineral Substances 0.000 description 1
- 235000010755 mineral Nutrition 0.000 description 1
- 229910052901 montmorillonite Inorganic materials 0.000 description 1
- VGIBGUSAECPPNB-UHFFFAOYSA-L nonaaluminum;magnesium;tripotassium;1,3-dioxido-2,4,5-trioxa-1,3-disilabicyclo[1.1.1]pentane;iron(2+);oxygen(2-);fluoride;hydroxide Chemical compound [OH-].[O-2].[O-2].[O-2].[O-2].[O-2].[F-].[Mg+2].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[Al+3].[K+].[K+].[K+].[Fe+2].O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2.O1[Si]2([O-])O[Si]1([O-])O2 VGIBGUSAECPPNB-UHFFFAOYSA-L 0.000 description 1
- FPLYNRPOIZEADP-UHFFFAOYSA-N octylsilane Chemical compound CCCCCCCC[SiH3] FPLYNRPOIZEADP-UHFFFAOYSA-N 0.000 description 1
- 150000002894 organic compounds Chemical group 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical compound [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
- 229920002503 polyoxyethylene-polyoxypropylene Polymers 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 235000013772 propylene glycol Nutrition 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 229910052624 sepiolite Inorganic materials 0.000 description 1
- 235000019355 sepiolite Nutrition 0.000 description 1
- 150000004756 silanes Chemical class 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical group [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 238000010183 spectrum analysis Methods 0.000 description 1
- 239000008107 starch Substances 0.000 description 1
- 235000019698 starch Nutrition 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 229910052902 vermiculite Inorganic materials 0.000 description 1
- 239000010455 vermiculite Substances 0.000 description 1
- 235000019354 vermiculite Nutrition 0.000 description 1
- 238000004876 x-ray fluorescence Methods 0.000 description 1
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P40/00—Technologies relating to the processing of minerals
- Y02P40/60—Production of ceramic materials or ceramic elements, e.g. substitution of clay or shale by alternative raw materials, e.g. ashes
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
Abstract
The invention relates to the technical field of ceramic membranes, and discloses a modified fly ash support, a modifying method of the fly ash support, a fly ash ceramic membrane, a preparation method and application thereof, wherein the modifying method of the fly ash support comprises the following steps: first contacting the fly ash support with a solution containing a polysaccharide matrix and/or a derivative thereof to form a polysaccharide matrix and/or a derivative layer on the surface of the fly ash support, thereby obtaining a modified fly ash support, wherein the composition for preparing the fly ash support comprises a first fly ash, a first organic forming agent and a first plasticizer, wherein the fly ash comprises a component M selected from TiO 2 At least one of CaO and MgO, the surface of the fly ash ceramic membrane prepared by adopting the modified fly ash support body provided by the invention does not generate cracks and pinholes, and the problem of pore blocking caused by penetration of membrane layer particles into the support body is solved, so that the fly ash ceramic membrane has higher porosity, bending strength, pure water flux and acid and alkali resistance.
Description
Technical Field
The invention relates to the technical field of ceramic membranes, in particular to a modified fly ash support, a modifying method of the fly ash support, a fly ash ceramic membrane, a preparation method and application thereof.
Background
Fly ash is an industrial waste with abundant reserves, low cost and easy availability, and the main components are silicon dioxide and aluminum oxide, the content of which is more than 70 percent, which is similar to the clay component in the raw materials of the traditional ceramics. In addition, fly ash itself has a large number of micropores and a relatively high specific surface area. The industrial waste can reduce environmental pollution and develop and produce low-cost ceramics with high added value.
CN106669440a discloses a modification method of ceramic membrane, which comprises the following steps: firstly, carrying out surface treatment on a ceramic membrane to obtain a fresh ceramic membrane; step two, silane compounds are coated on the surface of the ceramic film through an impregnation method or a deposition method; and thirdly, carrying out heat treatment on the ceramic film coated in the second step under a protective atmosphere, and naturally cooling to obtain the modified ceramic film.
CN107177226a discloses a surface modifier for flat ceramic membrane, which comprises octyl silane hydrolysis solution, nano titanium dioxide dispersion liquid and antistatic agent, and by adopting the surface modifier, the problem of difficult regeneration and cleaning of flat ceramic membrane is solved.
Therefore, even though a plurality of methods are used for modifying the fly ash ceramic membrane at present, the conventional method has the problems that cracks and pinholes are easy to generate on the surface of the prepared fly ash ceramic membrane, and the problem of pore blocking caused by penetration of membrane layer particles into a support body is difficult to solve, so that the performance of the ceramic membrane is obviously affected.
Disclosure of Invention
The invention aims to solve the problem that cracks and pinholes are easy to generate on the surface of a fly ash ceramic membrane in the prior art, and provides a modified fly ash support, a modifying method of the fly ash support, the fly ash ceramic membrane, a preparation method and application thereof.
In order to achieve the above object, a first aspect of the present invention provides a method for modifying the surface of a fly ash support, the method comprising: carrying out first contact on the fly ash support body and a solution containing a polysaccharide matrix and/or a derivative thereof to form a polysaccharide matrix and/or a derivative layer on the surface of the fly ash support body so as to obtain a modified fly ash support body;
the preparation method of the fly ash support comprises the following steps: mixing the composition for preparing the fly ash support with water, molding, and then roasting;
wherein the composition for preparing the fly ash support comprises a first fly ash, a first organic forming agent and a first plasticizer, the content of the first fly ash is 85-97 wt%, the content of the first organic forming agent is 0.9-7 wt% and the content of the first plasticizer is 1.6-9 wt% based on the total weight of the composition for preparing the fly ash support;
wherein the first fly ash contains a component M, and the component M is selected from TiO 2 At least one of CaO and MgO, and the content of the component M is 1-8 wt% based on the total weight of the fly ash.
The second aspect of the invention provides a modified fly ash support body prepared by the method.
The third aspect of the invention provides a method for preparing a fly ash ceramic membrane, which comprises the following steps: and carrying out second contact and sintering on the modified fly ash support and the fly ash coating liquid to form a fly ash layer on the modified fly ash support, thereby obtaining the fly ash ceramic membrane.
The invention provides a fly ash ceramic membrane prepared by the method, which comprises a fly ash support body and a fly ash layer arranged on the fly ash support body, wherein the average pore diameter of the fly ash support body is smaller than or equal to the average pore diameter of the fly ash layer.
The fifth aspect of the invention provides an application of the fly ash ceramic membrane in sewage treatment and gas dedusting.
The inventor of the invention discovers in the research that the fly ash support is modified by the polysaccharide matrix and/or the derivative thereof, and then the fly ash layer is loaded on the modified fly ash support to obtain the fly ash ceramic membrane with a two-layer structure.
Through the technical scheme, the surface of the fly ash ceramic membrane prepared by adopting the modified fly ash support body provided by the invention does not generate defects of cracks and pinholes and membrane layer particles cannot permeate into pores of the support body, so that the fly ash ceramic membrane has higher porosity, bending strength, pure water flux and acid and alkali resistance.
Drawings
FIGS. 1 and 2 are surface SEM images of a ceramic membrane of fly ash prepared in example 1 of the present invention;
FIGS. 3 and 4 are surface SEM images of the fly ash ceramic membrane prepared in comparative example 1 of the present invention;
FIG. 5 is a surface SEM image of a ceramic membrane of fly ash prepared in comparative example 2 of the invention.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
In the present invention, where not explicitly stated, neither "first" nor "second" represent a sequence, nor are they limiting as to each material or operation, only for distinguishing between each material or operation, e.g., "first" and "second" in "first fly ash" and "second fly ash" are merely for distinguishing to mean that this is not the same fly ash; the "first" and "second" of the "first organic molding agent" and "second organic molding agent" are merely for distinction to indicate that this is not the same organic molding agent.
The first aspect of the invention provides a method for modifying the surface of a fly ash support, comprising the following steps: carrying out first contact on the fly ash support body and a solution containing a polysaccharide matrix and/or a derivative thereof to form a polysaccharide matrix and/or a derivative layer on the surface of the fly ash support body so as to obtain a modified fly ash support body;
the preparation method of the fly ash support comprises the following steps: mixing the composition for preparing the fly ash support with water, molding, and then roasting;
wherein the composition for preparing the fly ash support comprises a first fly ash, a first organic forming agent and a first plasticizer, the content of the first fly ash is 85-97 wt%, the content of the first organic forming agent is 0.9-7 wt% and the content of the first plasticizer is 1.6-9 wt% based on the total weight of the composition for preparing the fly ash support;
wherein the first fly ash contains a component M, and the component M is selected from TiO 2 At least one of CaO and MgO, and the content of the component M is 1-8 wt% based on the total weight of the fly ash.
In the present invention, the polysaccharide substrate and/or its derivative is contained in an amount of 0.1 to 5% by weight, preferably 0.1 to 2% by weight, based on the total weight of the polysaccharide substrate and/or its derivative-containing solution.
In the present invention, preferably, the polysaccharide matrix is selected from at least one of cellulose, chitosan and chitin.
In the present invention, the average pore diameter of the fly ash support is 1 to 15. Mu.m, preferably 1 to 3. Mu.m.
In the invention, the average pore diameter parameter of the fly ash support is measured by a bubble point and average flow method of a GB/T32361-2015 separation membrane pore diameter test method.
In the present invention, preferably, at least 50% of the spherical morphology particles are contained in the solid particles of the fly ash support. In the invention, the spherical morphology particles of the fly ash support body are combined with the ceramic membrane with a secondary porous structure (the support body and the fly ash layer), so that the ceramic membrane has higher porosity.
In the invention, the porosity of the fly ash support body is 40-60%, and the volume weight is 1.2-2g/cm 3 The bending strength is 18-100MPa, and the pure water flux is 10-100m 3 /m 2 ·h·bar。
In the invention, the volume weight parameter and the porosity parameter of the fly ash support are respectively measured by a GB/T1966-1996 porous ceramic volume weight and apparent porosity test method; the pure water flux parameter and the bending strength parameter of the fly ash support are respectively measured by a HYT 064-2002 tubular ceramic microporous filter membrane test method.
In the present invention, the manner of the first contact is not particularly limited, and any one of lift impregnation, isovolumetric impregnation, coating and spraying may be used. The specific lift impregnation, isovolumetric impregnation, coating and spraying operations may be performed according to conventional technical means in the art, and the present invention is not described herein.
According to a preferred embodiment of the present invention, the first fly ash is present in an amount of 87 to 95% by weight, the first organic forming agent is present in an amount of 2 to 6% by weight, and the first plasticizer is present in an amount of 2 to 7% by weight, based on the total weight of the composition.
According to a more preferred embodiment of the present invention, the first fly ash is present in an amount of 89 to 93 wt.%, the first organic forming agent is present in an amount of 3 to 5 wt.%, and the first plasticizer is present in an amount of 3 to 6 wt.%, based on the total weight of the composition.
In the present invention, there is no need to add an inorganic molding agent such as kaolinite, illite, montmorillonite, vermiculite, sepiolite, etc. to the composition, and in the present invention, there is no need to add a pore-forming agent such as carbon black, starch-based powder, calcium carbonate, polystyrene particles, which are commonly used. Preferably, no additional inorganic shaping agent or pore-forming agent is included in the composition of the present invention.
In the present invention, the weight ratio of the composition to water may be 1: (0.2-1.2), preferably 1: (0.2-0.4).
In the present invention, the type and source of the first organic molding agent are selected in a wide range, and the first organic molding agent is an organic compound having a viscosity in the range of 3000 to 200000mpa·s.
According to a preferred embodiment of the present invention, the first molding agent is at least one selected from the group consisting of methylcellulose, carboxymethylcellulose, hydroxypropyl methylcellulose, polyvinyl alcohol and polyanionic cellulose, more preferably methylcellulose and/or carboxymethylcellulose. In the invention, the viscosity of the methyl cellulose can be 5000-200000 mPa.s, the viscosity of the carboxymethyl cellulose can be 5000-200000 mPa.s, and the polyvinyl alcohol can be polyvinyl alcohol with the marks PVA-1799 and/or PVA-1788. In the invention, preferably, the performance index of the polyanionic cellulose meets the requirements of GBT35928-2018 polyanionic cellulose.
In the present invention, the first plasticizer is preferably selected from at least one of glycerol, propylene glycol, glycerin, polyethylene glycol and polyvinyl alcohol, and is preferably different from the first organic molding agent.
In the present invention, the component M in the first fly ash may be selected from TiO 2 One, two or three of CaO and MgO, and the content of the component M is 2-5 wt% based on the total weight of the first fly ash.
According to a preferred embodiment of the present invention, the component M in the first fly ash may be selected from TiO 2 At least two of CaO and MgO, which may be TiO 2 Any combination of CaO and MgO, preferably TiO 2 And CaO, and TiO 2 And CaO in a weight ratio of 1: (0.2-1.2), further preferablySelecting 1: (0.5-1). In particular, when TiO 2 And CaO in a weight ratio of 1: and (0.5-1), the porosity and the bending strength of the prepared fly ash ceramic membrane can be further improved.
In the invention, based on the total weight of the first fly ash, al in the first fly ash 2 O 3 The content of (2) is 35-70 wt%, preferably 40-60 wt%; siO (SiO) 2 The content of (2) is 15 to 60% by weight, preferably 35 to 50% by weight. The inventors of the present invention found in the study that Al was used 2 O 3 Fly ash, in particular Al, with high content 2 O 3 When the content of (3) is in the range of 40-60 wt%, the porosity, bending strength, pure water flux and acid and alkali resistance of the prepared fly ash support body can be further improved.
In the invention, the TiO 2 、CaO、MgO、Al 2 O 3 And SiO 2 The content of (2) is measured by an X-ray fluorescence spectrum analysis method.
In the present invention, the composition for preparing the fly ash support may or may not contain polyacrylamide, and the content of the polyacrylamide is 0 to 1 wt% based on the total weight of the composition, and according to a preferred embodiment of the present invention, the content of the polyacrylamide is 0.01 to 0.05 wt% based on the total weight of the composition. In the invention, the addition of the polyacrylamide is favorable for forming the fly ash support body and improving the bending strength of the body, especially when the addition amount of the polyacrylamide is 0.01-0.05 wt%. In the present invention, the source of the polyacrylamide is not particularly limited, and may be commercially available or prepared by existing technical means.
In the invention, the molding may be preceded by aging and mud refining of the mixture obtained by mixing the composition with water, and then the molding is performed.
In the present invention, the aging refers to a process of placing a mixture obtained by mixing a composition and water in a container for a period of time to disperse each component substance in the mixture more uniformly, and in the present invention, the aging conditions are not particularly limited, and may include: the temperature is 10-40 ℃ and the time is 24-72h.
In the invention, the condition of the mud is not particularly limited, and can be manual mud or mechanical vacuum mud, and the purpose of the mud is to uniformly mix the aged materials and ensure that no air exists in the aged materials.
In the present invention, the molding may be a conventional molding method, and may be press molding or extrusion molding. Preferably, the wet blank mud section obtained after mud refining can be put into a steel die for extrusion molding.
In the present invention, the green body obtained by the molding is preferably tubular or plate-like in shape, and further preferably, the green body is tubular or plate-like in shape having at least one passage.
According to the invention, preferably, the channel is arranged coaxially to the blank. When the number of channels is more than 2, it is preferable that the different channels are each parallel.
In the present invention, the outer diameter of the tube is preferably 5-50mm, and the number of channels is preferably 1-100.
In the present invention, the plate shape preferably has a width of 60-1000mm, a thickness of 2-10mm, a wall thickness of 0.5-5mm, and a number of channels of 1-200.
In the present invention, the plate-like wall thickness refers to the minimum linear distance of the edge of the plate-like channel from the plate-like upper surface or lower surface, which refers to the surface parallel to the plate-like width direction.
In the present invention, the shape of the passage of the plate-like or tubular blank is not particularly limited, and may be changed according to the specific shape of the mold, for example, the cross section of the passage may be circular, triangular, square, or the like. According to a specific embodiment of the invention, the cross-sectional shape of the channel is circular, preferably the diameter of the circular shape is 0.2-40mm.
The green body of the pulverized coal support body prepared by the composition can have larger size and is not easy to bend. According to a preferred embodiment of the invention, the outer diameter of the tube is preferably 30-50mm. The size of the blank corresponds to the size of the extrusion opening of the die, and the size of the blank is changed when the size of the extrusion opening of the die is changed.
In the invention, the bending strength of the green body of the pulverized coal support body is 4-10MPa, more preferably 6-10MPa, and the ceramic membrane with higher bending strength is facilitated to be obtained under the condition that the bending strength of the green body of the pulverized coal support body is higher.
In the present invention, the green body of the fly ash support may be dried before the green body is baked, and preferably, the drying conditions include: the temperature is 90-120 ℃ and the time is 2-8h.
In the present invention, the conditions for the firing are not particularly limited, and the conditions for the firing preferably include: the temperature is 1200-1600 ℃, the time is 1-15h, and further preferably, the temperature is kept for 5-15h after the temperature rises to 1200-1600 ℃ at the temperature rising speed of 5-15 ℃/min.
The second aspect of the invention provides a modified fly ash support body prepared by the method.
The third aspect of the invention provides a method for preparing a fly ash ceramic membrane, which comprises the following steps: and carrying out second contact and sintering on the modified fly ash support and the fly ash coating liquid to form a fly ash layer on the modified fly ash support, thereby obtaining the fly ash ceramic membrane.
In the present invention, the manner of the second contact is not particularly limited, and any one of lift impregnation, isovolumetric impregnation, coating and spraying may be used. The specific lift impregnation, isovolumetric impregnation, coating and spraying operations may be performed according to conventional technical means in the art, and the present invention is not described herein.
In the present invention, the sintering conditions are not particularly limited, and preferably include: the temperature is 1100-1400 ℃, the time is 1-10h, and further preferably, the temperature is kept for 1-10h after the temperature is raised to 1100-1400 ℃ at the temperature rising speed of 5-15 ℃/min.
In the present invention, the fly ash coating liquid contains the second fly ash, preferably, the content of the second fly ash is 10 to 50 wt%, preferably, 20 to 40 wt%.
Preferably, the fly ash coating liquid further comprises: a second organic forming agent, a second plasticizer, a defoamer, a preservative and water.
Preferably, the content of the second organic forming agent in the fly ash coating liquid is 0.02-4 wt%, preferably 0.1-3 wt%; the content of the second plasticizer is 0.03 to 4.5 wt%, preferably 0.1 to 3 wt%; the content of defoamer is 0.08-3 wt%, preferably 0.1-2 wt%; the content of the preservative is 0.05 to 2 wt%, preferably 0.1 to 1 wt%.
Preferably, the content of water in the fly ash coating liquid is 40-80 wt%.
In the invention, the water refers to deionized water.
In the present invention, the components contained in the second fly ash and the first fly ash may be the same or different in content.
In the present invention, preferably, the content of the spherical morphology particles in each of the first fly ash and the second fly ash is 70-90%, the content of the non-spherical morphology particles is 10-30%, and the sum of the content of the non-spherical morphology particles and the content of the spherical morphology particles is 100%.
In the invention, the method for measuring the content of the spherical morphology particles in the first fly ash and the second fly ash is not particularly limited, and the measurement can be performed by a Markov laser particle sizer MS 2000.
According to a preferred embodiment of the present invention, al in the second fly ash 2 O 3 The content of (2) may be 35-70 wt%, preferably 40-60 wt%; siO (SiO) 2 The content of (C) may be 15 to 60% by weight, preferably 40 to 60% by weight.
In the present invention, the second organic molding agent may be the same as or different from the first organic molding agent; the second plasticizer and the first plasticizer may be the same or different.
In the present invention, the type and source of the defoaming agent are selected widely, and preferably the defoaming agent is at least one selected from polyether-type defoaming agents, silicone-type defoaming agents and mineral oil-type defoaming agents. Preferably, the polyether defoamer may be GP-type glycerol polyether and/or GPE-type polyoxyethylene polyoxypropylene glycerol ether.
In the present invention, the kind and source of the preservative is selected widely, and preferably the preservative is at least one selected from potassium sorbate, benzoic acid and sodium benzoate.
The invention provides a fly ash ceramic membrane prepared by the method, which comprises a fly ash support body and a fly ash layer arranged on the fly ash support body, wherein the average pore diameter of the fly ash support body is not larger than that of the fly ash layer.
According to a preferred embodiment of the present invention, the average pore size of the fly ash support is smaller than the average pore size of the fly ash layer.
In the present invention, the average pore diameter of the soot layer may be 0.5 to 1. Mu.m, preferably 0.5 to 0.8. Mu.m.
According to a preferred embodiment of the present invention, the ceramic film of fly ash has a porosity of 40-60% and a volume weight of 1.3-1.9g/cm 3 The bending strength is 18-100MPa, and the pure water flux is 3-30m 3 /m 2 H.bar, the acid corrosion mass loss rate is less than or equal to 0.3%, and the alkali corrosion mass loss rate is less than or equal to 0.5%.
According to a preferred embodiment of the invention, the porosity of the ceramic membrane of fly ash is 47-60%, preferably 50-60%, and the volume weight is 1.5-1.7g/cm 3 The bending strength is 30-100MPa, preferably 30-50MPa, and the pure water flux is 18-30m 3 /m 2 H.bar, preferably 27-30m 3 /m 2 H.bar, the acid corrosion mass loss rate is not more than 0.2%, and the alkali corrosion mass loss rate is not more than 0.3%.
In the invention, the acid corrosion mass loss rate is used for representing the acid resistance, and the alkali corrosion mass loss rate is used for representing the alkali resistance, wherein the acid resistance and the alkali resistance are measured by a method for testing acid and alkali corrosion resistance of porous ceramics of GB/T1970-1996.
In the invention, the volume weight parameter and the porosity parameter of the fly ash ceramic membrane are respectively measured by a GB/T1966-1996 porous ceramic volume weight and apparent porosity test method; the pure water flux parameter and the bending strength parameter of the fly ash ceramic membrane are respectively measured by a HYT 064-2002 tubular ceramic microporous membrane test method.
In the present invention, the thickness of the soot layer is selected to be wide, and according to a preferred embodiment of the present invention, the soot layer is further preferably 10 to 160 μm in thickness, and the soot layer is further preferably 90 to 110 μm in thickness. The embodiments of the present invention are exemplified by a soot layer thickness of 100 μm, and the present invention is not limited thereto.
The fifth aspect of the invention provides an application of the fly ash ceramic membrane in sewage treatment and gas dedusting.
The fly ash ceramic membrane provided by the invention is suitable for treating various types of sewage, and can be, for example, sewage in coal chemical industry, sewage in power plants and the like.
In the invention, because the fly ash ceramic membrane has larger porosity, the flux of sewage or gas can be effectively improved when sewage and gas are treated, and the purposes of improving the treatment efficiency and the treatment effect of the sewage or gas are achieved.
The present invention will be described in detail by examples.
In the following examples of the present invention,
average pore diameter parameters of the fly ash support and the fly ash layer are measured by a bubble point and average flow method of a GB/T32361-2015 separation membrane pore diameter test method;
the volume weight parameter and the porosity parameter of the ceramic membrane are respectively measured by a GB/T1966-1996 porous ceramic volume weight and apparent porosity test method;
the pure water flux parameter and the bending strength parameter of the ceramic membrane are respectively measured by a HYT 064-2002 tubular ceramic microporous membrane test method;
the content parameters of the spherical morphology particles of the fly ash ceramic membrane are measured by an electron scanning microscope, and specifically: each fly ash ceramic membrane sample is selected from 5 SEM pictures (magnification is 1000 times), each picture is selected from 300×300 μm area, and the content of spherical morphology particles with sphericity greater than 0.7 in the area in each picture is measured and respectively recorded as m 1 、m 2 、m 3 、m 4 And m 5 Wherein the content of the spherical morphology particles refers to the percentage of the number of particles with sphericity larger than 0.7 in a measurement area to the total number of particles, and the content of the spherical morphology particles of the fly ash ceramic membrane is = (m) 1 +m 2 +m 3 +m 4 +m 5 )/5. The sphericity was measured by a microscope, and sphericity= (4×pi×projection area)/(projection circumference×projection circumference).
Example 1
(1) A composition for producing a fly ash support, wherein the composition of the first fly ash is shown as S1 in table 1, and the amounts of the components in the composition are shown as table 2, was mixed with water in a weight ratio of 1:0.2, obtaining a mixed raw material;
wherein, the content of spherical morphology particles in the fly ash in the composition is 70 percent, the organic forming agent is methyl cellulose, and the plasticizer is glycerol;
(2) Ageing the mixed raw material obtained in the step (1) at 25 ℃ for 36 hours, mechanically and vacuum refining mud to obtain a wet blank mud section, and then putting the wet blank mud section into an extruder for extrusion molding to obtain a tubular blank body, wherein the inner diameter is 4mm, the outer diameter is 30mm, and the number of channels is 19;
(3) Drying the blank body obtained in the step (2) for 4 hours at 120 ℃, then heating to 1400 ℃ at a heating rate of 5 ℃/min, and preserving heat for 10 hours to obtain a fly ash support body A-1;
(4) The fly ash support body obtained in the step (3) is firstly contacted with a solution containing chitosan in a lifting and dipping mode, and then is dried at room temperature (25 ℃ and the same below) to form a chitosan layer on the surface of the fly ash support body, so that a modified fly ash support body is obtained, wherein the chitosan content in the solution containing chitosan is 0.8 wt%;
(5) Carrying out second contact on the modified fly ash support obtained in the step (4) and a fly ash coating liquid (the component of the second fly ash is shown as S1 in table 1, the content of each component in the fly ash coating liquid is shown as table 3) in a coating mode, then heating to 1400 ℃ at a heating rate of 6 ℃/min, and preserving heat for 8 hours to form a fly ash layer on the modified fly ash support, thereby obtaining a fly ash ceramic film B-1, wherein the thickness of the fly ash layer is 100 mu m, and the following steps are the same;
wherein the second forming agent in the fly ash coating liquid is carboxymethyl cellulose, the second plasticizer is polyvinyl alcohol, the defoaming agent is GP-type glycerol polyether, and the preservative is sodium benzoate;
observing the surface morphology of the ceramic powder coal ash film B-1 by an electron scanning microscope, as shown in fig. 1 and 2, the surface of the ceramic powder coal ash film B-1 is free of cracks and pinholes as shown in fig. 1, and the film layer of the ceramic powder coal ash film B-1 is free of pore permeation defects as shown in fig. 2; the physical properties of B-1 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-1 were measured and the results are shown in Table 4.
Example 2
(1) A composition for producing a fly ash support (the composition of the first fly ash is shown as S2 in table 1, the amounts of the components in the composition are shown as table 2) was mixed with water in a weight ratio of 1:0.4, obtaining a mixed raw material;
Wherein, the content of spherical morphology particles in the fly ash in the composition is 90 percent, the organic forming agent is carboxymethyl cellulose, and the plasticizer is glycerol;
(2) Ageing the mixed raw material obtained in the step (1) at 25 ℃ for 40 hours, mechanically and vacuum refining mud to obtain a wet blank mud section, and then putting the wet blank mud section into an extruder for extrusion molding to obtain a tubular blank;
(3) Drying the blank body obtained in the step (2) at 110 ℃ for 8 hours, then heating to 1500 ℃ at a heating rate of 8 ℃/min, and preserving heat for 8 hours to obtain a fly ash support body A-2;
(4) The fly ash support body obtained in the step (3) is subjected to first contact with a solution containing chitosan in a lifting and dipping mode, and then is dried at room temperature, so that a chitosan layer is formed on the surface of the fly ash support body, and a modified fly ash support body is obtained, wherein the chitosan content in the solution containing chitosan is 2 wt%;
(5) Carrying out second contact on the modified fly ash support obtained in the step (4) and a fly ash coating liquid (the component of the second fly ash is shown as S1 in table 1, the content of each component in the fly ash coating liquid is shown as table 3) in a coating mode, then heating to 1300 ℃ at a heating rate of 7 ℃/min, and preserving heat for 12 hours to form a fly ash layer on the modified fly ash support, so as to obtain a fly ash ceramic membrane B-2;
Wherein the second forming agent in the fly ash coating liquid is carboxymethyl cellulose, the second plasticizer is glycerol, the defoaming agent is GP type glycerol polyether, and the preservative is benzoic acid;
observing the surface morphology of the B-2 by an electron scanning microscope, wherein the surface of the fly ash ceramic membrane B-2 is similar to that of the FIG. 1 and FIG. 2, and has no crack or pinhole and no pore permeation of a membrane layer; the physical properties of B-2 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-2 were measured and the results are shown in Table 4.
Example 3
(1) A composition for producing a fly ash support (the composition of the first fly ash is shown as S3 in table 1, the amounts of the components in the composition are shown as table 2) was mixed with water in a weight ratio of 1:0.3, obtaining a mixed raw material;
wherein, the content of spherical morphology particles in the fly ash in the composition is 80 percent, the organic forming agent is carboxymethyl cellulose, and the plasticizer is polyethylene glycol;
(2) Ageing the mixed raw material obtained in the step (1) at 25 ℃ for 50 hours, mechanically and vacuum refining mud to obtain a wet blank mud section, and then putting the wet blank mud section into an extruder for extrusion molding to obtain a tubular blank;
(3) Drying the blank body obtained in the step (2) for 9 hours at 125 ℃, then heating to 1300 ℃ at a heating rate of 10 ℃/min, and preserving heat for 12 hours to obtain a fly ash support body A-3;
(4) The fly ash support body obtained in the step (3) is subjected to first contact with a solution containing chitosan in a lifting and dipping mode, and then is dried at room temperature, so that a chitosan layer is formed on the surface of the fly ash support body, and a modified fly ash support body is obtained, wherein the chitosan content in the solution containing chitosan is 0.1 wt%;
(5) Carrying out second contact on the modified fly ash support obtained in the step (4) and a fly ash coating liquid (the component of the second fly ash is shown as S1 in table 1, the content of each component in the fly ash coating liquid is shown as table 3) in a coating mode, then heating to 1400 ℃ at a heating rate of 5 ℃/min, and preserving heat for 10 hours to form a fly ash layer on the modified fly ash support, so as to obtain a fly ash ceramic membrane B-3;
wherein the second forming agent in the fly ash coating liquid is methyl cellulose, the second plasticizer is polyvinyl alcohol, the defoaming agent is GP-type glycerol polyether, and the preservative is potassium sorbate;
observing the surface morphology of the B-3 by an electron scanning microscope, wherein the surface of the fly ash ceramic membrane B-3 is similar to that of the FIG. 1 and FIG. 2, and has no crack or pinhole and no pore permeation defect; the physical properties of B-3 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-3 were measured and the results are shown in Table 4.
Example 4
The procedure of example 1 was followed except that the amounts of the components in the composition were appropriately adjusted, and the amounts of the components in the composition were as shown in Table 2, to give fly ash support A-4 and fly ash ceramic membrane B-4;
observing the surface morphology of the B-4 by an electron scanning microscope, wherein the surface of the fly ash ceramic membrane B-4 is free of cracks and pinholes and free of membrane layer non-porous defects similar to those of the FIG. 1 and FIG. 2; the physical properties of B-4 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-4 were measured and the results are shown in Table 4.
Example 5
The procedure of example 1 is followed, except that the fly ash has a composition as shown in S4 in Table 1, tiO 2 And CaO content of 8%; obtaining a fly ash support body A-5 and a fly ash ceramic membrane B-5;
observing the surface morphology of the B-5 by an electron scanning microscope, wherein the surface of the fly ash ceramic membrane B-5 is similar to that of the FIG. 1 and FIG. 2, and has no crack or pinhole and no pore permeation defect; the physical properties of B-5 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-5 were measured and the results are shown in Table 4.
Example 6
The procedure of example 1 was followed except that the first fly ash had a composition as shown in S5 of Table 1, and the fly ash did not contain TiO 2 Obtaining a fly ash support body A-6 and a fly ash ceramic membrane B-6;
observing the surface of the B-6 by an electron scanning microscope, and similar to the surfaces of the coal ash ceramic membrane B-6 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-6 has no cracks and pinholes and has a membrane layer object pore permeation defect; the physical properties of B-6 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-6 were measured and the results are shown in Table 4.
Example 7
The procedure of example 1 is followed except that the fly ash contains TiO 2 And CaO in a weight ratio of 1:0.2, the composition of the first fly ash is shown as S6 in Table 1, and a fly ash support A-7 and a fly ash ceramic membrane B-7 are obtained.
Observing the surface of the B-7 by an electron scanning microscope, and similar to the surfaces of the coal ash ceramic membrane B-7 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-7 has no cracks and pinholes and the membrane layer has no seepage defects; the physical properties of B-7 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-7 were measured and the results are shown in Table 4.
Example 8
According to the method of example 1, except that the composition of fly ash is as shown in S7 in Table 1, al in the first fly ash 2 O 3 The content of (C) is 35 wt%, siO 2 The content of (3) was 60% by weight, to obtain fly ash support A-8 and fly ash ceramic membrane B-8.
Observing the surface of the B-8 through an electron scanning microscope, and being similar to the surfaces of the coal ash ceramic membrane B-8 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-8 has no cracks and pinholes and has no pore permeation defect; the physical properties of B-8 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-8 were measured and the results are shown in Table 4.
Example 9
The procedure of example 1 was followed except that the content of polyacrylamide and plasticizer in the composition was 0.5% by weight and 5.5% by weight, respectively, to give fly ash support A-9 and fly ash ceramic membrane B-9.
Observing the surface of the B-9 by an electron scanning microscope, and similar to the surfaces of the coal ash ceramic membrane B-9 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-9 has no cracks and pinholes and the membrane layer has no seepage defects; the physical properties of B-9 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-9 were measured and the results are shown in Table 4.
Example 10
The procedure of example 1 was followed except that polyacrylamide was not contained in the composition and the content of plasticizer was 6% by weight, to obtain fly ash support A-10 and fly ash ceramic membrane B-10.
Observing B-10 by an electron scanning microscope, and similar to FIG. 1, the surface of the fly ash ceramic membrane B-10 has no crack or pinhole and no pore permeation defect of the membrane layer; the physical properties of B-10 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-10 were measured and the results are shown in Table 4.
Example 11
The procedure of example 1 was followed except that the contents of the components in the fly ash coating liquid were appropriately adjusted as shown in Table 2, to obtain a fly ash ceramic film B-11.
Observing the surface of the B-11 through an electron scanning microscope, and being similar to the surfaces of the coal ash ceramic membrane B-11 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-11 has no cracks and pinholes and has no pore permeation defect; the physical properties of B-11 were measured, and the results are shown in Table 3; the performance parameters of the fly ash support A-11 were measured and the results are shown in Table 4.
Example 12
The procedure of example 1 was followed except that the chitosan content of the chitosan-containing solution was 5% by weight, to obtain fly ash ceramic membrane B-12.
Observing the surface of the B-12 by an electron scanning microscope, and being similar to the surfaces of the coal ash ceramic membrane B-12 in fig. 1 and 2, the surface of the coal ash ceramic membrane B-12 has no cracks and pinholes and has no pore permeation defect; the physical properties of B-12 were measured, and the results are shown in Table 3; the performance parameters of fly ash support A-12 were measured and the results are shown in Table 4.
Comparative example 1
The procedure of example 1 was followed except that step (4) was not performed, to obtain fly ash ceramic membrane DB-1.
The surface morphology of DB-1 is observed by an electron scanning microscope, as shown in FIG. 3, and as can be seen from FIG. 3, the surface of the coal ash ceramic membrane DB-1 has obvious pinhole phenomenon, and pore permeation phenomenon (the coal ash layer particles permeate into the pores of the coal ash support) can also occur, as shown in FIG. 4; the physical properties of DB-1 were measured and the results are shown in Table 3.
Comparative example 2
The procedure of example 1 was followed except that the fly ash support in step (1) was replaced with a silicon carbide support DA-1 to obtain a fly ash ceramic membrane DB-2.
Observing the surface morphology of DB-2 by an electron scanning microscope, as shown in FIG. 5, it can be seen from FIG. 5 that obvious cracks exist on the surface of the coal ash ceramic membrane DB-2; the physical properties of DB-2 were measured and the results are shown in Table 3; the performance parameters of the fly ash support DA-1 were measured and the results are shown in Table 4.
TABLE 1
TABLE 2
TABLE 3 Table 3
TABLE 4 Table 4
As can be seen from tables 1 to 4 and fig. 1 to 5, the fly ash ceramic membrane prepared by the support and the modified fly ash support of the invention has a two-layer structure, and the fly ash ceramic membrane effectively avoids the defects of cracks, pinholes and pore permeation, thereby remarkably improving the comprehensive performance of the ceramic membrane.
In particular, the flyash ceramic membrane is suitable for treating sewage or gas containing solid particles with the particle size of more than 0.5-1 mu m, and the pore permeation phenomenon is generated in DB-1 due to the flyash ceramic membrane, so that the pure water flux is obviously reduced. In DB-2, the phenomenon of cracks is generated in the coal ash ceramic membrane, so that the flux of pure water is obviously increased, and the treatment effect is obviously affected when sewage or gas containing solid particles with the particle size of more than 0.5-1 mu m is treated. The ceramic membrane can effectively improve the treatment efficiency and the treatment effect of sewage or gas simultaneously when the sewage or gas is treated.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.
Claims (47)
1. A method of modifying a surface of a fly ash support, the method comprising: first contacting the fly ash support with polysaccharide matrix and/or derivative solution thereof to form a polysaccharide matrix and/or derivative layer on the surface of the fly ash support to obtain a modified fly ash support,
wherein the average pore diameter of the fly ash support body is 1-3 mu m;
wherein the porosity of the fly ash support body is 40-60% and the volume weight is 1.2-2g/cm 3 The bending strength is 18-100MPa, and the pure water flux is 10-100m 3 /m 2 ·h·bar；
The preparation method of the fly ash support comprises the following steps: mixing the composition for preparing the fly ash support with water, molding, and then roasting;
wherein the composition for preparing the fly ash support comprises a first fly ash, a first organic forming agent and a first plasticizer, the content of the first fly ash is 85-97 wt%, the content of the first organic forming agent is 0.9-7 wt% and the content of the first plasticizer is 1.6-9 wt% based on the total weight of the composition for preparing the fly ash support;
Wherein the first fly ash contains a component M, and the component M is selected from TiO 2 At least one of CaO and MgO, and the content of the component M is 1-8 wt% based on the total weight of the fly ash;
the polysaccharide matrix is selected from at least one of cellulose, chitosan and chitin.
2. The method according to claim 1, wherein the polysaccharide matrix and/or derivative thereof is present in an amount of 0.1-5 wt%, based on the total weight of the polysaccharide matrix and/or derivative solution.
3. The method according to claim 2, wherein the polysaccharide matrix and/or derivative thereof is present in an amount of 0.1-2 wt%, based on the total weight of the polysaccharide matrix and/or derivative solution.
4. A process according to any one of claims 1 to 3, wherein the first fly ash is present in an amount of 87 to 95% by weight, the first organic forming agent is present in an amount of 2 to 6% by weight, and the first plasticizer is present in an amount of 2 to 7% by weight, based on the total weight of the composition.
5. The method of claim 4, wherein the weight ratio of the composition for preparing the fly ash support to water is 1: (0.2-1.2).
6. The method of claim 5, wherein the weight ratio of the composition for preparing the fly ash support to water is 1: (0.2-0.4).
7. The method of claim 4, wherein the first organic shaping agent is selected from at least one of methylcellulose, carboxymethylcellulose, hydroxypropyl methylcellulose, polyvinyl alcohol, and polyanionic cellulose; the first plasticizer is at least one selected from glycerol, propylene glycol, raw tung oil, polyethylene glycol, castor oil, soybean oil, oleic acid and polyvinyl alcohol.
8. The method according to any one of claims 1-3, 5-7, wherein the component M is selected from TiO 2 At least two of CaO and MgO.
9. The method of claim 8, wherein the component is TiO 2 And CaO, and TiO 2 And CaO in a weight ratio of 1: (0.2-1.2).
10. The method of claim 8, wherein the TiO 2 And CaO in a weight ratio of 1: (0.5-1).
11. The method of claim 4, wherein the component M is selected from TiO 2 At least two of CaO and MgO.
12. The method of claim 11, wherein the component is TiO 2 And CaO, and TiO 2 And CaO in a weight ratio of 1: (0.2-1.2).
13. The method of claim 11, wherein the TiO 2 And CaO in a weight ratio of 1: (0.5-1).
14. The method of any one of claims 1-3, 5-7, 9-13, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 35-70 wt%; siO (SiO) 2 The content of (2) is 15-60 wt%.
15. The method of claim 14, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 40-60 wt%; siO (SiO) 2 The content of (C) is 35-50 wt%.
16. The method of claim 4, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 35-70 wt%; siO (SiO) 2 The content of (2) is 15-60 wt%.
17. The method of claim 16, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 40-60 wt%; siO (SiO) 2 The content of (C) is 35-50 wt%.
18. The method of claim 8, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 35-70 wt%; siO (SiO) 2 The content of (2) is 15-60 wt%.
19. The method of claim 18, wherein Al in the fly ash is based on the total weight of the first fly ash 2 O 3 The content of (2) is 40-60 wt%; siO (SiO) 2 The content of (C) is 35-50 wt%.
20. The method of any one of claims 1-3, 5-7, 9-13, 15-19, wherein the composition further comprises a polyacrylamide in an amount of 0.01-1 wt% based on the total weight of the composition.
21. The method of claim 20, wherein the polyacrylamide is present in an amount of 0.01 to 0.05 wt.%.
22. The method of claim 4, wherein the composition further comprises a polyacrylamide in an amount of 0.01 to 1 weight percent, based on the total weight of the composition.
23. The method of claim 22, wherein the polyacrylamide is present in an amount of 0.01 to 0.05 wt.%.
24. The method of claim 8, wherein the composition further comprises a polyacrylamide in an amount of 0.01 to 1 weight percent, based on the total weight of the composition.
25. The method of claim 24, wherein the polyacrylamide is present in an amount of 0.01 to 0.05 wt.%.
26. The method of claim 14, wherein the composition further comprises a polyacrylamide in an amount of 0.01 to 1 weight percent, based on the total weight of the composition.
27. The method of claim 26, wherein the polyacrylamide is present in an amount of 0.01 to 0.05 wt.%.
28. The method of any one of claims 1-3, 5-7, 9-13, 15-19, 21-27, wherein the shaping is by compression or extrusion.
29. The method of claim 28, the firing conditions comprising: the temperature is 1200-1600 ℃ and the time is 1-15h.
30. The method of claim 4, wherein the molding is compression molding or extrusion molding.
31. The method of claim 30, the firing conditions comprising: the temperature is 1200-1600 ℃ and the time is 1-15h.
32. The method of claim 8, wherein the molding is compression molding or extrusion molding.
33. The method of claim 32, the firing conditions comprising: the temperature is 1200-1600 ℃ and the time is 1-15h.
34. The method of claim 14, wherein the molding is compression molding or extrusion molding.
35. The method of claim 34, the firing conditions comprising: the temperature is 1200-1600 ℃ and the time is 1-15h.
36. The method of claim 20, wherein the molding is compression molding or extrusion molding.
37. The method of claim 36, the firing conditions comprising: the temperature is 1200-1600 ℃ and the time is 1-15h.
38. A modified fly ash support prepared by the method of any one of claims 1-37.
39. The preparation method of the fly ash ceramic membrane comprises the following steps:
the modified fly ash support of claim 38 is subjected to a second contact with a fly ash coating liquid and then sintered to form a fly ash layer on the modified fly ash support, thereby obtaining a fly ash ceramic membrane.
40. The process according to claim 39, wherein the fly ash coating liquid contains the second fly ash in an amount of 10 to 50% by weight.
41. The method of claim 40, wherein the sintering conditions comprise: the temperature is 1100-1400 ℃ and the time is 1-10h.
42. The method of claim 40, wherein the soot layer has a thickness of 10-160 μm.
43. The fly ash ceramic membrane produced by the production method of any one of claims 39 to 42, wherein the fly ash ceramic membrane comprises a modified fly ash support and a fly ash layer arranged on the modified fly ash support, and an average pore diameter of the modified fly ash support is not greater than an average pore diameter of the fly ash layer.
44. The fly ash ceramic membrane of claim 43 wherein the average pore size of the fly ash layer is 0.5-1 μm.
45. The fly ash ceramic membrane of claim 44 wherein the average pore size of the fly ash layer is 0.5-0.8 μm.
46. The fly ash ceramic membrane of claim 44 having a bulk weight of 1.3 to 1.9g/cm 3 The porosity is 40-60%, the bending strength is 18-100MPa, and the pure water flux is 3-30m 3 /m 2 H.bar, the acid corrosion mass loss rate is less than or equal to 0.3%, and the alkali corrosion mass loss rate is less than or equal to 0.5%.
47. Use of a ceramic fly ash membrane according to any one of claims 43 to 46 in sewage treatment or gas dedusting.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910985134.6A CN112661493B (en) | 2019-10-16 | 2019-10-16 | Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910985134.6A CN112661493B (en) | 2019-10-16 | 2019-10-16 | Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112661493A CN112661493A (en) | 2021-04-16 |
| CN112661493B true CN112661493B (en) | 2023-07-14 |
Family
ID=75400437
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910985134.6A Active CN112661493B (en) | 2019-10-16 | 2019-10-16 | Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112661493B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115872772B (en) * | 2022-12-30 | 2023-10-24 | 中南大学 | Preparation method of fly ash-based ceramic membrane support |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH11188217A (en) * | 1997-12-26 | 1999-07-13 | Toshiba Ceramics Co Ltd | Production of ceramic filter |
| CN103755328B (en) * | 2014-02-07 | 2014-12-24 | 刘旭红 | Preparation method of tubular ceramic membrane support body |
| CN107337442A (en) * | 2017-07-11 | 2017-11-10 | 芜湖市宝艺游乐科技设备有限公司 | A kind of particle stabilized foam process prepares alumina ceramic supporting body and preparation method thereof |
| CN108479420A (en) * | 2018-05-08 | 2018-09-04 | 南方科技大学 | A kind of microfiltration ceramic membrane and preparation method thereof |
| CN108911706B (en) * | 2018-08-20 | 2021-06-22 | 南京工业大学 | Co-sintering preparation method of fly ash-based ceramic microfiltration membrane |
| CN109173748A (en) * | 2018-10-26 | 2019-01-11 | 唐山开滦化工科技有限公司 | A kind of preparation method of coal ash ceramic film |
-
2019
- 2019-10-16 CN CN201910985134.6A patent/CN112661493B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN112661493A (en) | 2021-04-16 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1031382C (en) | Composite membranes | |
| CN110922204B (en) | Preparation method of low-temperature sintered alumina ceramic membrane | |
| CN113105223B (en) | Preparation and application of whisker-shaped ceramic membrane with low cost and high permeability | |
| KR101591932B1 (en) | Method for manufacturing porous clay-based ceramic membrane with ceramic coating layer and ceramic membrane manufactured thereby | |
| CN111545078A (en) | Flat ceramic membrane and preparation method thereof | |
| CN108201794B (en) | Ceramic separation membrane for water treatment using silicon carbide subjected to oxidation treatment and preparation method thereof | |
| JP6770437B2 (en) | Honeycomb structure with cement husk composition containing crystalline inorganic fiber material | |
| CN108440008B (en) | High-porosity ceramic filter material and preparation method thereof | |
| US10442739B2 (en) | Porous plate-shaped filler | |
| US8784541B2 (en) | Cordierite-based composite membrane coated on cordierite monolith | |
| CN112661492A (en) | Composition for producing fly ash ceramic membrane, fly ash ceramic membrane and preparation method and application thereof | |
| CN111804159B (en) | Silicon carbide whisker reinforced silicon carbide ceramic separation membrane based on tape casting and preparation method thereof | |
| CN112661493B (en) | Modified fly ash support, modification method of fly ash support, fly ash ceramic membrane, preparation method and application of fly ash ceramic membrane | |
| CN112044285A (en) | High-flux ceramic filtering membrane and preparation method thereof | |
| WO2000045945A1 (en) | Method for manufacturing filter having ceramic porous film as separating film | |
| CN110885237B (en) | Preparation method of low-temperature sintered alumina ceramic support | |
| CN112661520B (en) | Fly ash-alumina composite ceramic membrane and preparation method and application thereof | |
| KR101811199B1 (en) | COMPOSITION FOR SiC SUPPORT LAYER AND SiC MEMBRANE HAVING AN Al2O3 COATING LAYER USING THE SAME AND METHOD FOR MANUFACTURING THE SAME | |
| JP5068788B2 (en) | One-end-sealed zeolite membrane substrate tube | |
| CN113548871A (en) | Fly ash composition, raw material for producing fly ash ceramic membrane, preparation method and application thereof | |
| CN115180970B (en) | Composition for producing fly ash-based porous ceramic, fly ash-based porous ceramic and preparation method and application thereof | |
| CN115180926B (en) | Coal-based solid waste-alumina composite ceramic membrane and preparation method and application thereof | |
| CN115957636B (en) | Ceramic flat membrane for drinking water and preparation method thereof | |
| JPH0571548B2 (en) | ||
| KR102416209B1 (en) | METHOD FOR MANUFACTURING CERAMIC MEMBRANE FOR WATER TREATMENT USING THE OXIDATION TREATED SiC |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231213 Address after: 102211 Shenhua Low Carbon 001 Mailbox, Naukograd, Changping District, Beijing Patentee after: Beijing low carbon clean energy Research Institute Address before: 100011 Beijing Dongcheng District, West Binhe Road, No. 22 Patentee before: CHINA ENERGY INVESTMENT Corp.,Ltd. Patentee before: Beijing low carbon clean energy Research Institute |
|
| TR01 | Transfer of patent right |