CN113336537B - Tubular ceramic membrane for industrial sewage treatment and preparation process - Google Patents
Tubular ceramic membrane for industrial sewage treatment and preparation process Download PDFInfo
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Abstract
The application relates to the technical field of ceramic membranes, and particularly discloses a tubular ceramic membrane for industrial sewage treatment and a preparation process thereof. A tubular ceramic membrane for industrial sewage treatment comprises the following raw materials: yellow mud, fly ash, a pore-forming agent, methyl cellulose, a dispersing agent, a lubricating agent, graphene powder and water; the preparation method comprises the following steps: s1: respectively mixing the raw materials to obtain a first mixture and a second mixture; s2: mixing the first mixture and the second mixture, stirring in a water bath, and aging to obtain a third mixture; s3: casting and molding the third mixture to obtain a green body; s4: and drying and sintering the green body to obtain the tubular ceramic membrane. The tubular ceramic membrane for industrial sewage treatment has strong acid and alkali corrosion resistance, and the service life of the tubular ceramic tube is effectively prolonged; in addition, the preparation method has the advantage of reducing energy consumption in the sintering process.
Description
Technical Field
The application relates to the technical field of ceramic membranes, in particular to a tubular ceramic membrane for industrial sewage treatment and a preparation process thereof.
Background
Ceramic membranes, also known as inorganic ceramic membranes, are asymmetric membranes formed by preparing inorganic ceramic materials through a special process. The ceramic membrane is classified into a tubular ceramic membrane and a flat ceramic membrane. Micropores are densely distributed on the tube wall of the tubular ceramic membrane, under the action of pressure, raw material liquid flows in the membrane tube or outside the membrane, small molecular substances or liquid permeate the membrane, and large molecular substances or solid are intercepted by the membrane, so that the purposes of separation, concentration, purification, environmental protection and the like are achieved.
At present, the related art, such as application document with application number 201510177545.4, discloses a process for preparing a tubular ceramic membrane by a rotation method, which comprises the steps of taking alumina powder as aggregate, adding silicon carbide whisker, a pore-forming agent, a sintering aid and water to mix into slurry, grinding, then aging and drying the slurry, then adding a plasticizer and water to grind again, and carrying out die-tube compression molding, drying, sintering and cleaning on the mixture to obtain a tubular support body; adding ground aluminum isopropoxide into hot deionized water for magnetic stirring, adding nitric acid, a dispersing agent and a defoaming agent in batches, uniformly stirring to obtain sol, and then aging the sol; sealing the outer surface of the support body, coating, gelatinizing, drying and sintering.
Aiming at the related technologies, the fertilizer industry is high water consumption and high pollution, and the discharge of a large amount of incompletely-treated fertilizer wastewater causes the increase of the content of nitrogen and phosphorus in the water body, so that the water body is deteriorated. The indexes of main overproof pollutants in the wastewater of the fertilizer plant are ammonia nitrogen, sulfide and total cyanide, the ammonia nitrogen content of the water is high, the wastewater contains toxic total cyanide and sulfide, and the wastewater has strong acidity or alkalinity and poor biodegradability. The inventors believe that the tubular ceramic membrane of the related art is easily corroded in a waste solution of strong acid or strong base, and cannot maintain long-term rupture strength, resulting in a low service life of the tubular ceramic membrane.
Disclosure of Invention
In order to prolong the service life of the tubular ceramic membrane, the application provides the tubular ceramic membrane for industrial sewage treatment and a preparation process thereof.
In a first aspect, the present application provides a tubular ceramic membrane for industrial wastewater treatment, which adopts the following technical scheme:
a tubular ceramic membrane for industrial sewage treatment is prepared from the following raw materials in parts by weight: 85-100 parts of yellow mud, 20-30 parts of fly ash, 25-33 parts of pore-forming agent, 2-4 parts of methyl cellulose, 1-5 parts of dispersant, 1-5 parts of lubricant, 10-15 parts of graphene powder and 20-25 parts of water.
By adopting the technical scheme, compared with the commercialized ceramic membrane raw material, the yellow mud has the advantages of wide raw material source, easiness in sintering, low cost and the like, has good economic benefit, and is beneficial to popularization of industrial application of the ceramic membrane, and the main component of the yellow mud is Al 2 O 3 、Fe 2 O 3 And SiO 2 And contains various fluxing agents (e.g. Na) 2 O、K 2 O and the like) and is easy to form solid solution and generate liquid phase in the sintering process, and can promote particle rearrangement and sintering densification, so that the prepared tubular ceramic membrane has higher mechanical strength. SiO 2 2 Belongs to acidic oxides, can resist corrosion of various acids,and SiO 2 The reaction with alkali is slow and difficult to carry out, so that the tubular ceramic membrane has better acid and alkali corrosion resistance.
The fly ash is used as industrial solid waste, has large discharge amount and pollutes the environment, and the main component of the fly ash comprises Fe 2 O 3 And SiO 2 And the sintering temperature range is narrow when pure yellow mud is used as a raw material, so that the sintering process is difficult to control, and the excellent performance of the ceramic membrane is not sufficiently exerted.
The pore-forming agent helps to strengthen the heat transfer effect in the sintering process of the tubular ceramic membrane, and is beneficial to the tubular ceramic membrane to form more pores with uniform size and uniform distribution, so that the tubular ceramic membrane has the advantages of high separation efficiency and stable effect.
The graphene powder has stable two-dimensional property, is not easy to react with acid and alkali, so that the prepared tubular ceramic membrane has strong acid and alkali corrosion resistance, has a lubricating effect, can reduce agglomeration of yellow mud, and is beneficial to uniformity of components of the tubular ceramic membrane, and the using effect is stable.
Therefore, the prepared tubular ceramic membrane has high separation efficiency, stable effect and higher mechanical strength, can be well applied to the industrial sewage treatment process, has stronger acid-base corrosion resistance, and effectively prolongs the service life of the tubular ceramic tube.
Preferably, the yellow mud is oversize material treated by a screen, and the mesh number of the screen is 800-1340 meshes.
By adopting the technical scheme, the yellow mud has strong viscosity and is not easy to disperse, the particle size of the yellow mud is selected within the range, certain cohesive force can be kept between the yellow mud, the yellow mud and other raw materials can be uniformly dispersed, and the prepared tubular ceramic membrane has uniform components, stable quality and stable use effect.
Preferably, the fly ash is oversize material treated by a screen, and the mesh number of the screen is 1000-1340 meshes.
By adopting the technical scheme, the particle size of the fly ash is slightly smaller than that of the yellow mud, and the fly ash is added into the raw materials, so that gaps among the yellow mud can be filled, the compactness among the raw materials is improved, and the tubular ceramic membrane has higher mechanical strength.
Preferably, the pore-forming agent is at least one of methyl methacrylate and starch.
By adopting the technical scheme, the methyl methacrylate is insoluble in water, the particles of the methyl methacrylate enter between yellow mud matrix particles and occupy certain point positions, then the methyl methacrylate is burnt out in the sintering process to form gas escape, and the occupied space is changed into a gap to form a communicated pore structure, so that the diffusion resistance of the filter medium is reduced, and the permeability of the tubular ceramic membrane is improved. The starch has fine particles and smooth surface, is matched with methyl methacrylate to play a role in lubrication, so that the methyl methacrylate is more easily dispersed in other components, and the uniformity of the pores of the tubular ceramic membrane is enhanced.
Preferably, the dispersant is at least one of sodium lauryl sulfate and cellulose acetate.
By adopting the technical scheme, the dispersing agent can be selected from sodium dodecyl sulfate, cellulose acetate or a mixture of the sodium dodecyl sulfate and the cellulose acetate, so that the stability of a raw material dispersing system is enhanced, the comprehensive performance of the tubular ceramic membrane is improved, the sodium dodecyl sulfate is matched with yellow mud, the hydrophilicity of the tubular ceramic membrane is improved, and the water flux of the tubular ceramic membrane is improved.
Preferably, the lubricant is at least one of glycerin, glycerol and octadecanoic acid.
By adopting the technical scheme, the lubricant is added into the raw materials, so that the wettability of the surface of the tubular ceramic membrane is improved, cracks are avoided in the sintering process, and the quality of a finished product of the tubular ceramic membrane is improved.
In a second aspect, the present application provides a method for preparing a tubular ceramic membrane for industrial sewage treatment, which adopts the following technical scheme:
a preparation method of a tubular ceramic membrane for industrial sewage treatment comprises the following preparation steps:
s1: mixing yellow mud, fly ash, methyl cellulose and a pore-forming agent, and then uniformly stirring to obtain a first mixture; mixing a dispersing agent, a lubricating agent and graphene powder, and then uniformly stirring to obtain a second mixture;
s2: mixing the first mixture and the second mixture in the step S1 with water according to the formula ratio, and then uniformly stirring; obtaining a raw material liquid which is mixed uniformly; then, stirring the raw material liquid in a water bath; then placing the raw material liquid in a thermostat with the temperature of 30-35 ℃ for aging to obtain a third mixture;
s3: injecting the third mixture into a mold for preparing the tubular ceramic membrane, and molding the third mixture to obtain a green body of the tubular ceramic membrane;
s4: and drying and sintering the green body to obtain the tubular ceramic membrane.
By adopting the technical scheme, the tubular ceramic membrane is prepared by mixing different raw materials step by step, which is beneficial to improving the distribution uniformity of each component in the tubular ceramic membrane; the raw material liquid is subjected to water bath and aging, and then injection molding, drying and sintering are carried out, so that holes with the same size are formed in the tubular ceramic membrane, and the tubular ceramic membrane has proper porosity, so that the filtering performance of the tubular ceramic membrane is improved.
Preferably, the drying temperature in the S4 is 80-90 ℃.
By adopting the technical scheme, the drying temperature of S4 is 80-90 ℃, the temperature of 80-90 ℃ is close to the boiling point of water, the temperature is set to accelerate the volatilization of water and the drying efficiency of the formed green body, and the green body is preheated; meanwhile, the drying temperature of 80-90 ℃ is not enough to ensure that the moisture moves too violently in the green body, so that the influence of the violent moisture movement on the pores of the tubular ceramic membrane is avoided.
Preferably, the sintering temperature in S4 is 1100-1150 ℃.
By adopting the technical scheme, the temperature of 1100-1150 ℃ is slightly lower than the sintering temperature of a common tubular ceramic tube, so that the energy consumption in the sintering process is effectively reduced.
In summary, the present application has the following beneficial effects:
1. since the method adopts the yellow mud to replace the commercialized ceramic membrane raw material, the yellow mud has the advantages of wide raw material source, easy sintering, low cost and the like compared with the commercialized ceramic membrane raw material, and has good economic benefit, and the main component of the yellow mud is Al 2 O 3 、Fe 2 O 3 And SiO 2 And contains various fluxing agents, solid solution and liquid phase are easily formed in the sintering process, the rearrangement of particles and the sintering densification can be promoted, so that the prepared tubular ceramic membrane has higher mechanical strength, can be well applied to the industrial sewage treatment process, and SiO 2 Belongs to acidic oxide, can resist corrosion of various acids, and is SiO 2 The reaction with alkali is slow and difficult to carry out, so that the tubular ceramic membrane has better acid and alkali corrosion resistance, and the service life of the tubular ceramic tube is effectively prolonged.
2. At least one of methyl methacrylate and starch is preferably adopted as a pore-forming agent in the application, because methyl methacrylate is insoluble in water, the particles enter between the yellow mud matrix particles, occupy a certain point position, later, gas escape is formed after loss of combustion in the sintering process, the occupied space becomes a pore structure communicated with the gap formation, starch enables methyl methacrylate to be more easily dispersed in other components, the tubular ceramic membrane is favorable for forming more even pores with uniform size and uniform distribution, so that the tubular ceramic membrane has the advantages of high separation efficiency and stable effect.
3. According to the method, the uniformity of each component in the tubular ceramic membrane is improved by mixing different raw materials step by step, the raw material liquid is subjected to water bath and aging and then subjected to injection molding, drying and sintering, holes with the same size are formed in the tubular ceramic membrane, and the tubular ceramic membrane has proper porosity, so that the filtering performance of the tubular ceramic membrane is improved.
Detailed Description
The present application will be described in further detail with reference to examples.
Unless otherwise specified, all the raw materials referred to in this application are commonly commercially available. One source of feedstock referred to in this application is provided below: yellow mud can be purchased from mineral products Limited of Lingshu county, and the impurity content is less than 1%;
specific surface area of the fly ash is 300-500m 2 Kg, loss on ignition is less than or equal to 2 percent; can be purchased from Shijiazhuang Daheniang mineral products processing Co., Ltd;
the methyl cellulose can be purchased from Feicheng Yutian chemical Co., Ltd, and the water content is less than or equal to 5 percent;
methyl methacrylate is available from chemical Limited, Tongda, of the south-JI century;
starch is available from national agricultural starch, Inc. of Foshan, and has a starch model of GN 803;
octadecanoic acid is commercially available from the Xian Keda chemical plant;
the graphene powder can be purchased from T-3H type graphene powder of Hengfu Kai science and technology Limited in Shenzhen.
Examples
Example 1
A tubular ceramic membrane for industrial sewage treatment is prepared from the following raw materials in parts by weight:
8.5kg of yellow mud, 2.0kg of fly ash, 2.5kg of pore-forming agent, 0.2kg of methyl cellulose, 0.1kg of dispersing agent, 0.1kg of lubricating agent, 1.0kg of graphene powder and 2.0kg of water.
The yellow mud is oversize obtained by sieving with a 600-mesh sieve; the fly ash is oversize material obtained by sieving with a 800-mesh sieve; the pore-forming agent is methyl methacrylate; the dispersant is sodium dodecyl sulfate; the lubricant is glycerol.
The tubular ceramic membrane is prepared by the following steps:
s1: mixing yellow mud, fly ash, methyl cellulose and methyl methacrylate, and stirring for 10min to obtain a first mixture; mixing sodium dodecyl sulfate, glycerol and graphene powder, and stirring for 5min to obtain a second mixture;
s2: mixing the first mixture and the second mixture in the step S1 with water according to the formula ratio, and stirring for 5min to obtain a raw material solution; then stirring the raw material liquid in water bath at the temperature of 70 ℃ for 25 min; then placing the raw material liquid in a thermostat at 30 ℃ for aging for 32 hours to obtain a third mixture;
s3: injecting the third mixture into a mold for preparing the tubular ceramic membrane, and applying 50MPa pressure to the mold to mold the third mixture to obtain a green body of the tubular ceramic membrane;
s4: and drying the green body at the temperature of 80 ℃ for 2h, and sintering the dried green body at the temperature of 1100 ℃ for 5h to obtain the tubular ceramic membrane.
Example 2
A tubular ceramic membrane for industrial sewage treatment is prepared from the following raw materials in parts by weight:
9.0kg of yellow mud, 2.5kg of fly ash, 3.0kg of pore-forming agent, 0.3kg of methyl cellulose, 0.3kg of dispersing agent, 0.3kg of lubricating agent, 1.2kg of graphene powder and 2.3kg of water.
The yellow mud is oversize obtained by sieving with a 600-mesh sieve; the fly ash is oversize material obtained by sieving with a 800-mesh sieve; the pore-forming agent is methyl methacrylate; the dispersant is sodium dodecyl sulfate; the lubricant is glycerol.
The tubular ceramic membrane is prepared by the following steps:
s1: mixing yellow mud, fly ash, methyl cellulose and methyl methacrylate, and stirring for 10min to obtain a first mixture; mixing sodium dodecyl sulfate, glycerol and graphene powder, and stirring for 5min to obtain a second mixture;
s2: mixing the first mixture and the second mixture in the step S1 with water according to the formula ratio, and stirring for 5min to obtain a raw material solution; then stirring the raw material liquid in water bath at the temperature of 80 ℃ for 27 min; then placing the raw material liquid in a thermostat at 33 ℃ for aging for 40h to obtain a third mixture;
s3: injecting the third mixture into a mold for preparing the tubular ceramic membrane, and applying 50MPa pressure to the mold to mold the third mixture to obtain a green body of the tubular ceramic membrane;
s4: and drying the green body at 85 ℃ for 2h, and sintering the dried green body at 1130 ℃ for 5h to obtain the tubular ceramic membrane.
Example 3
A tubular ceramic membrane for industrial sewage treatment is prepared from the following raw materials in parts by weight:
10kg of yellow mud, 3.0kg of fly ash, 3.3kg of pore-forming agent, 0.4kg of methyl cellulose, 0.5kg of dispersant, 0.5kg of lubricant, 1.5kg of graphene powder and 2.5kg of water.
The yellow mud is oversize obtained by sieving with a 600-mesh sieve; the fly ash is oversize material obtained by sieving with a 800-mesh sieve; the pore-forming agent is methyl methacrylate; the dispersant is sodium dodecyl sulfate; the lubricant is glycerol.
The tubular ceramic membrane is prepared by the following steps:
s1: mixing yellow mud, fly ash, methyl cellulose and methyl methacrylate, and stirring for 10min to obtain a first mixture; mixing sodium dodecyl sulfate, glycerol and graphene powder, and stirring for 5min to obtain a second mixture;
s2: mixing the first mixture and the second mixture in the step S1 with water according to the formula ratio, and stirring for 5min to obtain a raw material solution; then stirring the raw material liquid in water bath at the temperature of 90 ℃ for 30 min; then placing the raw material liquid in a thermostat at 35 ℃ for aging for 48 hours to obtain a third mixture;
s3: injecting the third mixture into a mold for preparing the tubular ceramic membrane, and applying 50MPa pressure to the mold to mold the third mixture to obtain a green body of the tubular ceramic membrane;
s4: and drying the green body at 90 ℃ for 2h, and sintering the dried green body at 1150 ℃ for 5h to obtain the tubular ceramic membrane.
Example 4
A tubular ceramic membrane for industrial wastewater treatment, which differs from example 3 in that: the yellow mud of this example is oversize material obtained by passing through a 1340 mesh sieve.
Example 5
A tubular ceramic membrane for industrial wastewater treatment, which differs from example 3 in that: the yellow mud in this example is oversize material obtained by sieving with a 1000-mesh sieve.
Example 6
A tubular ceramic membrane for industrial wastewater treatment, which differs from example 3 in that: the yellow mud in this example is oversize material obtained by sieving with 800 mesh sieve.
Example 7
A tubular ceramic membrane for industrial wastewater treatment, differing from example 6 in that: the fly ash of this example is oversize material obtained by passing through a 1340 mesh sieve.
Example 8
A tubular ceramic membrane for industrial wastewater treatment, differing from example 6 in that: the fly ash of this example is oversize material obtained by sieving with a 1200 mesh sieve.
Example 9
A tubular ceramic membrane for industrial wastewater treatment, differing from example 6 in that: the fly ash of this example is oversize material obtained by sieving with a 1000-mesh sieve.
Example 10
A tubular ceramic membrane for industrial wastewater treatment, differing from example 9 in that: this example replaces the methyl methacrylate of example 9 with an equal weight of starch.
Example 11
A tubular ceramic membrane for industrial wastewater treatment, differing from example 9 in that: the pore former selected in this example was a mixture of 2.0kg of methyl methacrylate and 1.3kg of starch.
Example 12
A tubular ceramic membrane for industrial wastewater treatment, differing from example 11 in that: the amount of yellow mud in this example was 9.5 kg.
Example 13
A tubular ceramic membrane for industrial wastewater treatment, differing from example 11 in that: the amount of yellow mud in this example was 8.5 kg.
Example 14
A tubular ceramic membrane for industrial wastewater treatment, which differs from example 12 in that: the amount of graphene powder used in this example was 1.3 kg.
Example 15
A tubular ceramic membrane for industrial wastewater treatment, which differs from example 12 in that: the amount of graphene powder used in this example was 1.0 kg.
Comparative example
Comparative example 1
A tubular ceramic membrane, differing from example 1 in that: the raw materials and the preparation method are different, and the raw materials comprise the following raw materials by weight:
8.5kg of alumina powder, 2.0kg of silicon carbide whisker, 0.8kg of starch, 1.6kg of kaolin, 0.2kg of hydroxypropyl methyl cellulose and 1.5kg of water.
The tubular ceramic membrane is prepared by the following steps:
mixing alumina powder, silicon carbide whisker, starch and kaolin, stirring for 5min to obtain uniform slurry, and standing for 24h under natural conditions; then adding hydroxypropyl methyl cellulose and continuing stirring for 2 min; and then, carrying out compression molding by using a pipe die under the pressure of 30MPa, drying for 2h at 80 ℃ by using an electric oven after molding, heating to 800 ℃ at the temperature of 200 ℃ by using a muffle furnace at the heating rate of 7 ℃/min, sintering, heating to 1250 ℃ at the heating rate of 4 ℃/min, keeping the temperature at 1250 ℃ for about 2h, and then cooling and taking out to obtain the tubular ceramic membrane.
Comparative example 2
A tubular ceramic membrane differing from example 1 in that: fly ash is not added into the raw materials for preparing the tubular ceramic membrane.
Comparative example 3
A tubular ceramic membrane differing from example 1 in that: graphene powder is not added in the raw materials for preparing the tubular ceramic membrane.
Performance test
Test samples: the tubular ceramic membranes obtained in examples 1 to 15 were used as test samples 1 to 15, and the tubular ceramic membranes obtained in comparative examples 1 to 3 were used as control samples 1 to 3.
The test method comprises the following steps: and (3) testing the bending strength and the acid and alkali corrosion resistance of the tubular ceramic membrane according to the standard specified in the HY/T064-2002 tubular ceramic microporous filter membrane test method.
And (3) test results: the test results of the test samples 1 to 15 are shown in Table 1, and the test results of the control samples 1 to 3 are shown in Table 2.
TABLE 1 test results for test samples 1-15
As can be seen from table 1, when the test samples 1, 2 and 3 are compared, the bending strength and the acid and alkali corrosion resistance of the tubular ceramic membrane prepared in the embodiments 1 to 3 of the present application satisfy the requirements of "Q320124 NJHC 01-2016-tubular ceramic membrane enterprise standard", which indicates that the tubular ceramic membrane prepared by using yellow mud and fly ash as main raw materials completely meets the requirements of the enterprise standard, can realize mass production, and can be popularized for industrial application; and the mass loss rate of the test sample 1, the test sample 2 and the test sample 3 in an acid-base solution is lower than the standard value of the mass loss rate specified in Q320124 NJHC 01-2016-tubular ceramic membrane enterprise standard by 0.5%, which indicates that the tubular ceramic membrane prepared by the embodiment of the application has good acid and alkali corrosion resistance.
As can be seen from table 1, when the test samples 4, 5, 6 and 3 are compared, the resistance to acid-base corrosion does not change significantly, but the bending strength of the test samples 4 to 6 is improved significantly, which indicates that the grain size of yellow mud has a large influence on the bending strength of the tubular ceramic membrane; the yellow mud with the grain size of 12-15 microns is obtained after the yellow mud is screened by a screen with the mesh number of 800-1340 meshes, and the yellow mud with the grain size of 12-15 microns can keep better cohesive force per se and can be uniformly dispersed with other raw materials, so that the tubular ceramic membrane has uniform components and better mechanical strength.
As can be seen from table 1, when comparing the test samples 7, 8, 9 and 6, the resistance to acid and alkali corrosion does not change significantly, but the bending strength of the test samples 7-9 is further improved, which means that after the fly ash is screened by a screen with the mesh number of 1000-1340 meshes, the obtained fly ash with the particle size of 10-12 microns is beneficial to improving the mechanical strength of the tubular ceramic membrane, because the particle size of the fly ash is slightly smaller than that of the yellow mud, the fly ash can fill the gap between the yellow mud, the compactness between the raw materials is improved, and thus the mechanical strength of the tubular ceramic membrane is improved.
As can be seen from table 1, when the test sample 10, the test sample 11 and the test sample 9 are compared, the test sample 10 adopts single starch as the pore-forming agent, the pore-forming performance is poor, and pores formed on the ceramic membrane are not uniform, so that the bending strength of the prepared tubular ceramic membrane is reduced; the test sample 11 adopts methyl methacrylate and starch as pore-forming agents for compounding, the methyl methacrylate has strong pore-forming capability, and the starch enables methyl methacrylate to be uniformly dispersed in the raw materials, so that the tubular ceramic membrane can form pores with uniform size and uniform distribution, and the tubular ceramic membrane can keep high mechanical strength; and the pores with uniform size and uniform distribution can ensure that the contact area between the pores and the acid-base liquid is consistent, avoid the breakage of the tubular ceramic membrane caused by continuous corrosion of acid-base liquid and larger pores, and improve the acid-base corrosion resistance of the tubular ceramic membrane.
As can be seen from table 1, when comparing the test sample 11 with the test sample 12, the bending strength of the prepared tubular ceramic membrane is slightly increased after the amount of yellow mud is reduced; comparing the test sample 13 with the test sample 12, the bending strength of the obtained tubular ceramic membrane was reduced.
As can be seen from table 1, when the test samples 12 and 14 are compared with the test sample 15, the mass loss rate of the tubular ceramic membrane in acid and alkali solutions is improved after the amount of the graphene powder is reduced, which indicates that the acid and alkali resistance of the tubular ceramic membrane is weakened after the amount of the graphene powder is reduced, and thus indicates that the acid and alkali resistance of the tubular ceramic membrane of graphene powder has a certain enhancing effect.
TABLE 2 test results for control samples 1-3
As can be seen from tables 1 and 2, when comparing the reference sample 1 with the test sample 1, the bending strength of the tubular ceramic membrane prepared in the embodiment 1 of the present application is not much different from that of the reference sample 1, which indicates that the mechanical strength of the tubular ceramic membrane prepared in the embodiment of the present application meets the use requirement, and the mass loss rate of the tubular ceramic membrane prepared in the embodiments 1 to 4 in acid and alkali solutions is significantly lower than that of the reference sample 1, which indicates that the tubular ceramic membrane prepared in the embodiment of the present application has better acid and alkali corrosion resistance.
As can be seen from tables 1 and 2, when comparing the comparison sample 2 with the test sample 1, the bending strength of the comparison sample 2 is reduced more significantly than that of the test sample 1, which indicates that the fly ash plays an important role in maintaining stable mechanical strength of the yellow mud-based tubular ceramic tube, and the fly ash can make the yellow mud-based tubular ceramic tube exert more excellent service performance; compared with the test sample 1, the mass loss rate of the control sample 2 in the acid and alkali solutions is increased because the fly ash contains part of the acid and alkali resistant SiO 2 And the acid and alkali resistance of the tubular ceramic membrane can be enhanced.
It can be known from tables 1 and 2 that, when comparing the comparison sample 3 with the test sample 1, the bending strength has no obvious difference, but the mass loss rate of the comparison sample 3 is obviously higher than that of the test sample 1, and the graphene powder has strong acid and alkali corrosion resistance, which indicates that the acid and alkali corrosion resistance of the tubular ceramic tube can be effectively improved by adding the graphene powder into the raw materials when preparing the tubular ceramic tube.
As can be seen from tables 1 and 2, when the comparison sample 1, the comparison sample 3 and the test sample 1 are compared, graphene powder is not added to the raw material of the comparison sample 3, and although the mass loss rate of the comparison sample 3 is higher than that of the test sample 1, the mass loss rate is still significantly lower than that of the comparison sample 1, which indicates that the graphene powder does not play a dominant role in enhancing the acid and alkali resistance of the tubular ceramic membrane, and further indicates that yellow mud and fly ash play an important role in promoting the acid and alkali corrosion resistance of the tubular ceramic membrane.
The specific embodiments are only for explaining the present application and are not limiting to the present application, and those skilled in the art can make modifications to the embodiments without inventive contribution as required after reading the present specification, but all the embodiments are protected by patent law within the scope of the claims of the present application.
Claims (6)
1. The tubular ceramic membrane for industrial sewage treatment is characterized by being prepared from the following raw materials in parts by weight: 85-100 parts of yellow mud, 20-30 parts of fly ash, 25-33 parts of pore-forming agent, 2-4 parts of methyl cellulose, 1-5 parts of dispersant, 1-5 parts of lubricant, 10-15 parts of graphene powder and 20-25 parts of water;
the yellow mud is oversize material treated by a screen, and the mesh number of the screen is 800-1340 meshes;
the fly ash is oversize material treated by a screen, and the mesh number of the screen is 1000-1340 meshes;
the pore-forming agent is methyl methacrylate and starch.
2. A tubular ceramic membrane for industrial wastewater treatment according to claim 1, wherein: the dispersant is at least one of sodium dodecyl sulfate and cellulose acetate.
3. A tubular ceramic membrane for industrial wastewater treatment according to claim 1, wherein: the lubricant is at least one of glycerol, glycerol and octadecanoic acid.
4. A process for the preparation of a tubular ceramic membrane for industrial wastewater treatment according to any of claims 1 to 3, wherein: comprises the following preparation steps:
s1: mixing yellow mud, fly ash, methyl cellulose and a pore-forming agent, and then uniformly stirring to obtain a first mixture; mixing a dispersing agent, a lubricating agent and graphene powder, and then uniformly stirring to obtain a second mixture;
s2: mixing the first mixture, the second mixture and water according to the formula amount in the step S1, and then uniformly stirring; obtaining a raw material liquid which is mixed uniformly; then, stirring the raw material liquid in a water bath; then placing the raw material liquid in a thermostat with the temperature of 30-35 ℃ for aging to obtain a third mixture;
s3: injecting the third mixture into a mold for preparing the tubular ceramic membrane, and molding the third mixture to obtain a green body of the tubular ceramic membrane;
s4: and drying and sintering the green body to obtain the tubular ceramic membrane.
5. The process according to claim 4, wherein the preparation process of the tubular ceramic membrane for industrial sewage treatment comprises the following steps: and the drying temperature in the S4 is 80-90 ℃.
6. The process according to claim 4, wherein the ceramic tube membrane is prepared by a method comprising the following steps: the sintering temperature in the S4 is 1100-1150 ℃.
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