CN113121155A - Environment-friendly energy-saving geopolymer material taking river and lake sludge as single raw material and preparation method thereof - Google Patents
Environment-friendly energy-saving geopolymer material taking river and lake sludge as single raw material and preparation method thereof Download PDFInfo
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- C—CHEMISTRY; METALLURGY
- C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
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- C04B28/00—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements
- C04B28/006—Compositions of mortars, concrete or artificial stone, containing inorganic binders or the reaction product of an inorganic and an organic binder, e.g. polycarboxylate cements containing mineral polymers, e.g. geopolymers of the Davidovits type
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- C04B18/00—Use of agglomerated or waste materials or refuse as fillers for mortars, concrete or artificial stone; Treatment of agglomerated or waste materials or refuse, specially adapted to enhance their filling properties in mortars, concrete or artificial stone
- C04B18/04—Waste materials; Refuse
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- C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
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- C04B2111/28—Fire resistance, i.e. materials resistant to accidental fires or high temperatures
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- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/30—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values
- C04B2201/32—Mortars, concrete or artificial stone characterised by specific physical values for heat transfer properties such as thermal insulation values, e.g. R-values for the thermal conductivity, e.g. K-factors
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- C04B2201/00—Mortars, concrete or artificial stone characterised by specific physical values
- C04B2201/50—Mortars, concrete or artificial stone characterised by specific physical values for the mechanical strength
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- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
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Abstract
The invention relates to an eco-polymer environment-friendly energy-saving material taking river and lake sludge as a single raw material, which uses Na2SiO3 and KOH and/or NaOH solution as alkali activators and sludge as the single raw material, wherein the sludge as the raw material adopts sludge with the water content of 35% -50% after preliminary dehydration treatment, the water content is defined as the mass ratio of free water to solid matters in the sludge, the mass ratio of the Na2SiO3 amount to the solid matters in the sludge is 7.1% -29.7%, and the mass ratio of the KOH and/or NaOH amount to the solid matters in the sludge is 6.6% -28.9%; the geopolymer environment-friendly energy-saving material taking the river and lake sludge as the single raw material adopts fresh water sludge of rivers, lakes, waterworks and the like as the single raw material for geopolymer reaction, has wide sources and low cost, solves a series of environmental pollution problems and social problems caused by stacking of a large amount of sludge, and has obvious social benefit and economic benefit.
Description
Technical Field
The invention belongs to the technical field of building materials, and particularly relates to an environment-friendly and energy-saving geopolymer material taking river and lake sludge as a single raw material and a preparation method thereof.
Background
Concrete is the most common building material used in the construction industry for construction and repair. Portland cement is the most common binder in concrete production, and the production process consumes considerable amount of non-renewable natural resources and emits a large amount of greenhouse gases. Each 1 ton of portland cement produced required consumption of 1.5 tons of non-renewable raw materials and emission of 0.9 tons of CO2 into the air. With the concern of global warming and the deep mind of sustainable development concept, the global civil engineering industry is actively explored, and a new environment-friendly energy-saving material is sought to replace the traditional portland cement.
While various governments, scientific research institutions and enterprises at all levels actively seek new materials, a great amount of industrial solid waste is generated by various industrial activities every year, the development of economic construction in China is hindered, and the sludge is a huge waste material which is difficult to treat; for example, sludge (hereinafter, simply referred to as sludge) precipitated from a tap water plant in a river basin pollutes local air, soil and underground water if the sludge cannot be effectively treated in time, and occupies a serious and tense land resource, thereby causing a series of social problems. Governments in various regions invest a great deal of manpower and material resources to treat and digest the sludge every year, but no effective scheme capable of fundamentally solving the pollution problem and the social problem is found.
In view of the above problems, some experts and scholars have been dedicated to research on how to solidify the sludge or to solve the problem of pollution caused by the sludge and the waste of land resources by producing sludge baked bricks. The main solidification method adopted at present is to mix Portland cement or lime with sludge with certain parameters, and the method has obvious limitations, such as low tolerance to acid, incapability of effectively locking heavy metals in the sludge and the like; another treatment method is high-temperature calcination, i.e. mixing a certain amount of quicklime, gypsum and the like with sludge to prepare a blank, maintaining the blank in an environment of 60-90 ℃ for several days, and then calcining the blank at a high temperature of not less than 1050 ℃ for more than 6 hours to obtain various sintered clay bricks. The method has the disadvantages that while a large amount of energy is consumed in the production process and considerable greenhouse gases are emitted, 100 percent of sludge cannot be used as a raw material, and other natural resources still need to be consumed.
The geopolymer technology proposed by the french scholar Davidovits has caused a wide interest in the materials industry and civil engineering industry for decades. The geopolymer reaction is to excite Si and Al in the raw materials into free states through an alkali activator and recombine the free states into an amorphous anisotropic 3D network, so that the raw materials are converted into an inorganic binder material. Compared with portland cement, the geopolymer cement has the advantages of short curing time, better acid and alkali corrosion resistance, high-efficiency locking of heavy metals and other harmful chemical elements in raw materials, extremely low energy consumption in the production process, extremely low greenhouse gas emission and the like. Based on these advantages, a large number of enterprises and scientific research units seek to use industrial solid wastes to produce novel environmentally friendly and energy-saving binder products through geopolymerization.
In the existing geopolymer production technology, the selection range of raw materials is narrow, and high-reaction active substances such as kaolin, metakaolin, fly ash and silica micropowder generated after high-temperature combustion are mainly adopted. For low-reactivity raw materials, the traditional process cannot be effectively utilized, and the produced product cannot be widely used due to the problems of low strength, high heat conductivity coefficient and the like.
Disclosure of Invention
The invention aims to provide a high-strength geopolymer environment-friendly energy-saving material produced by using Na2SiO3 and KOH solution as an alkali activator and using low-reaction activated sludge as a single raw material and a preparation method thereof.
In order to solve the technical problems, the invention discloses an environment-friendly and energy-saving geopolymer material taking river and lake sludge as a single raw material, wherein Na2SiO3 and KOH and/or NaOH solution are used as alkali activators, and the sludge is used as the single raw material, wherein the sludge as the raw material is subjected to primary dehydration treatment, the water content of the sludge is 35% -50%, the water content is defined as the mass ratio of free water to solid matters in the sludge, the mass ratio of the Na2SiO3 to the solid matters in the sludge is 7.1% -29.7%, and the mass ratio of the KOH and/or NaOH to the solid matters in the sludge is 6.6% -28.9%.
Preferably, the total mass of compounds of the main elements Si, Al, Fe, Na in the sludge is not less than 75% of the solids content of the sludge.
A preparation method of an environment-friendly and energy-saving geopolymer material taking river and lake sludge as a single raw material comprises the following steps:
s1: drying the sludge;
s2: crushing and sieving;
s3: preparing a geopolymer reaction precursor slurry;
s4: forming and maintaining to obtain a finished product;
in S3, Na2SiO3 and KOH and/or NaOH solution are used as alkali activators, sludge is used as a single raw material, the two raw materials are mixed to form a mixture, and the molar ratio of OH-, Na, K, Al, Si and Fe in the mixture in a reaction system is controlled as follows:
the molar ratio is 1: si (Al + Fe) =1: 4.3-5.7.
The molar ratio is 2: (Na + K): (Al + Fe) =1 (0.5-1.5), OH-: Al + Fe) =1 (0.7-2.0).
Preferably, in S2, the total mass of the compounds of the main elements Si, Al, Fe, Na in the screened sludge is not less than 75% of the solid content in the sludge.
In S1, the moisture content of the sludge for drying is between 20 and 50 percent; the drying environment temperature is controlled between 105 ℃ and 110 ℃ and ventilation treatment is needed.
Preferably, in S2, the dried sludge prepared in S1 is subjected to crushing treatment and then passed through a 170-mesh sieve to obtain sludge particles.
Preferably, in S3, the sludge is placed in an oven at a temperature of 45-65 ℃ and the temperature of the sludge particles is ensured to be between 45-65 ℃; heating the stirrer container to 45-65 deg.C, stirring the sludge in the stirrer at 40-80 r/min; and slowly pouring the alkali activator solution into the sludge, continuously stirring for several minutes after the alkali activator solution is completely poured, then increasing the rotating speed to be not less than 100r/min, and continuously stirring for several minutes to fully mix the sludge and the alkali activator to obtain uniform geopolymer reaction precursor slurry A.
Further, the sludge is placed in an oven at 50-60 ℃ to ensure that the temperature of the sludge particles is between 50-60 ℃; heating the stirrer container to 60 ℃, and placing the sludge in a stirrer for stirring at the rotating speed of 60 r/min; and slowly pouring the alkali activator solution into the sludge, continuously stirring for 2 minutes after the alkali activator solution is completely poured, increasing the rotating speed to 150r/min, and continuously stirring for 3 minutes to fully mix the sludge and the alkali activator to obtain uniform geopolymer reaction precursor slurry A.
Preferably, the uniform geopolymer reaction precursor slurry A is stirred, the stirring speed is set to be not less than 200r/min, the stirring is carried out for several minutes, then the speed is reduced to be not more than 180r/min, the stirring is carried out for several minutes, and a plurality of stirring cycles with high and low matched speeds are formed, so that the geopolymer reaction precursor slurry B for further reaction is obtained.
Furthermore, the low-speed stirring time is not shorter than 1/3 of the high-speed stirring time in each stirring period, the total time of each stirring period is not more than 10min, and the total stirring time is not less than 20 min.
Further, stirring the uniform geopolymer reaction precursor slurry A, setting the stirring speed to 240r/min for stirring for 4 minutes, then reducing the speed to 150r/min for stirring for 2 minutes to form a 6-minute stirring period with high and low speeds, and circulating for 5 stirring periods, wherein the total stirring time in the period is 30 minutes.
Preferably, in S4, the mold is heated to 60-70 ℃, the stirred slurry of the working polymer reaction precursor is poured in, and the mixture is vibrated for several minutes until no obvious bubbles are blown out from the slurry; moving the die to a curing box at 60-70 ℃, standing for 4 hours, raising the temperature by 10 ℃ every four hours, standing for curing for 12 hours, raising the curing temperature to 90-100 ℃, adjusting the relative humidity in the curing box to 40 +/-5%, standing for 12 hours, and then demolding; and (3) after demolding, placing the geopolymer product in a 25 +/-5 ℃ environment, and maintaining for 6 days or more in a ventilated environment.
Further, the mold is moved into a curing box with the temperature of 60-70 ℃, the temperature is raised by 10 ℃ every four hours after the mold is placed still for 4 hours, and the relative humidity in the curing box is 100% during the period of standing and curing for 12 hours.
The raw materials adopt fresh water sludge of rivers, lakes, waterworks and the like as the single raw material for the reaction of the geopolymer, the source is wide, the cost is low, a series of environmental pollution problems caused by stacking a large amount of sludge and social problems caused by occupying land resources are thoroughly solved while the high-strength geopolymer material is produced, and the geopolymer environment-friendly energy-saving material has obvious social benefits and economic benefits; in addition, the geopolymer material produced by the invention uses the alkali activators Na2SiO3 and KOH with simple components, thereby reducing the difficulty of preparing the alkali activators and having positive significance for widely popularizing the geopolymer material and improving the production efficiency of workers and equipment. The short curing period lays a solid foundation for large-scale industrial production. The uniaxial compressive strength of the sludge geopolymer material after 7-day curing reaches more than 30MPa, the A-grade fireproof performance is realized, the heat conductivity coefficient is 0.1-0.2W/m.K, and the sludge geopolymer material can be used as a high-strength environment-friendly energy-saving material binder or a prefabricated member and becomes a new option in the building material market. The invention overcomes the problems of high energy consumption and high pollution in the existing sludge treatment process, and provides a new idea and method for treating solid wastes such as municipal sludge, industrial solid wastes, municipal wastes and the like.
Drawings
FIG. 1 is a schematic diagram showing the relationship between the rotation speed and the stirring time;
FIG. 2 is a graph showing the relationship between curing temperature and time;
figure 3 is a bar graph of uniaxial compressive strength of four versions (examples 1, 2, comparative examples 1, 2) of the geopolymer product.
Detailed Description
The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.
It will be understood that terms such as "having," "including," and "comprising," when used herein, do not preclude the presence or addition of one or more other elements or groups thereof.
In the invention, effective connection cannot be formed among particles among raw material sludge, and the particles are difficult to agglomerate together to generate strength, and the strength can be formed only by connecting or agglomerating basic particles together by macromolecular chains and avoiding scattering and collapse in macroscopic mechanics. We have found that geopolymers Si-O4 and Al-O4 are linked together by covalent bonds to form Si-O4 and Al-O4 tetrahedra and finally form 3D networks, the more Si-O4 and Al-O4 tetrahedra, the more 3D networks capable of producing macroscopic strength are formed, the more geopolymers are formed, the higher the material strength is, and although a certain 3D network based on Si-O4 and Al-O4 tetrahedra is formed in the preparation process of common baking-free bricks and the like, the formation amount is not enough, and the effect of 'changing the amount to cause quality to change' is difficult to achieve. Based on the discovery, a breakthrough method for preparing the high-strength environment-friendly and energy-saving geopolymer material is further developed.
The molecular structures of the Si-O4 and Al-O4 tetrahedra are as follows:
in order to generate enough Si-O4 and Al-O4 tetrahedral molecules in the geopolymer reaction precursor slurry, the dosage of an alkali activator needs to be strictly controlled, sludge serving as a raw material is subjected to primary dehydration treatment, the water content of the sludge is 35-50%, the water content is defined as the mass ratio of free water to solid matters in the sludge, the mass ratio of the dosage of Na2SiO3 to the solid matters in the sludge is 7.1-29.7%, and the mass ratio of the dosage of KOH and/or NaOH to the solid matters in the sludge is 6.6-28.9%.
The total mass of the compounds of main elements Si, Al, Fe and Na in the sludge is not less than 75 percent of the solid content in the sludge.
In the method, Na2SiO3 and KOH and/or NaOH solution are used as alkali activator, sludge is used as a single raw material, the two raw materials are mixed to form a mixture, and the molar ratio of OH-, Na, K, Al, Si and Fe in the mixture in a reaction system is controlled as follows:
the molar ratio is 1: si (Al + Fe) =1: 4.3-5.7;
the molar ratio is 2: (Na + K): (Al + Fe) =1 (0.5-1.5), OH-: Al + Fe) =1 (0.7-2.0).
The following is a further description by way of examples and comparative examples.
(1) Production raw material information
The geopolymer reaction raw material is sludge (hereinafter referred to as sludge) generated in the sedimentation process of Binjiang waterworks of Zhongji Water utilities GmbH of Suzhou province of Jiangsu province, and the component detection results are shown in Table 1:
table 1 main components of raw material sludge
| Chemical composition | Mass fraction (%) |
| SiO2 | 52.89 |
| Al2O3 | 20.10 |
| CO2 | 10.29 |
| Fe2O3 | 5.969 |
| CaO | 3.434 |
| K2O | 2.665 |
| MgO | 2.254 |
| TiO2 | 0.833 |
| Na2O | 0.674 |
| P2O5 | 0.331 |
| SO3 | 0.179 |
| MnO | 0.145 |
Table 1 shows the general component detection expression patterns, all in the form of oxides; for example, Na2O refers to the expression of only one common component of the sodium salt, and Na2O is not actually present in the sludge.
The alkali activator is granular KOH and powdery Na2SiO3 which are sold in the market, the purities of the two chemicals are not less than 95 percent, and the solvent adopts deionized water sold in the market.
(2) Processing of raw materials
And (3) naturally evaporating water after the sludge is stacked on the bank, monitoring the water content, and drying when the water content is between 20 and 30 percent, wherein the drying environment temperature is strictly controlled between 105 and 110 ℃, and ventilation treatment is required. Too high drying temperature can cause the silt to agglomerate, increases the broken degree of difficulty by a wide margin.
The sludge is crushed after being fully dried, 100% of sludge particles in mass fraction are required to pass through a 200-mesh sieve, and preferably more than 95% of sludge particles in mass fraction are required to pass through a 240-mesh sieve, so that the whole sludge particles are kept in a finer granularity, the reaction area is increased, and sufficient reaction activity is ensured.
In the embodiment, the sludge is naturally dried for 3 days, then the water content is measured to be 28 percent, and then the sludge is placed in a drying oven at 105 ℃ for drying; crushing by using a crusher until 100% by mass of sludge particles pass through a 200-mesh sieve, and 98% by mass of sludge particles pass through a 240-mesh sieve.
(3) Manufacture of geopolymer materials
The molar Ratio of Si (Al + Fe) in the raw material components is 1.9, and the requirement of Mol Ratio 1 is met. Preparing an alkali activator solution by taking 1000g of sludge, 500g of deionized water, Na2SiO3 and KOH according to the scheme in the table 2:
table 2 examples of alkali activators
| Example 1 | Example 2 | Comparative example 1 | Comparative example 2 | |
| Na2SiO3KOH mass (g) | 150 | 225 | 94 | 300 |
| K + Na/Al + Fe mol ratio | 0.8 | 1.2 | 0.5 | 1.6 |
| OH-1Mol ratio of Al + Fe | 0.8 | 1.2 | 0.5 | 1.6 |
Preparing an alkali activator solution: the preparation of the alkali activator solution is carried out according to the two molar ratios of Mol Ratio 1 and Mol Ratio 2. Dissolving Na2SiO3 and KOH in water, stirring until Na2SiO3 and KOH are completely dissolved, and sealing the stirring container to prevent water evaporation in the process of preparing the solution. Stirring is continued until the temperature of the solution is reduced to between 60 and 70 ℃.
The sludge was placed in an oven at 50-60 c for more than 6 hours to ensure that all sludge particles were between 50-60 c. Heating the stirrer container to 60 ℃, and placing the sludge in a stirrer for stirring at the rotating speed of 60 r/min; meanwhile, slowly pouring the alkali activator solution into the sludge, continuously stirring for 2 minutes after completely pouring, then increasing the rotating speed to 150r/min, and continuously stirring for 3 minutes to fully mix the sludge and the alkali activator to obtain uniform geopolymer reaction precursor slurry; can prevent the activator from excessively fast water diffusion at 50-60 deg.C.
Setting the stirring speed to 240r/min for stirring for 4 minutes, then reducing the stirring speed to 150r/min for stirring for 2 minutes to form a 6-minute stirring period with high and low speeds, and circularly stirring for 5 continuous periods in this way, wherein the relationship between the rotating speed and the stirring time is shown in figure 1. In the stirring process, the stirring container needs to be sealed to prevent water evaporation and be continuously heated, so that the temperature of the reaction precursor slurry is always between 50 and 60 ℃, and energy is continuously input for the geopolymerization reaction. In experiments, the temperature of the reaction precursor slurry is obviously increased, the water of the excitant is lost too fast, the reaction precursor slurry is easy to become viscous in a short time, and the reaction precursor slurry is even prone to solidification when being stirred to the later stage, so that the stirring is difficult to be carried out; through high-low speed matching stirring, particularly stirring for 4 minutes at a stirring speed of 240r/min, then reducing the speed to 150r/min, and stirring for 2 minutes, under the condition of forming a high-low speed matching stirring period of 6 minutes, the temperature of the reaction precursor slurry is always between 50 and 60 ℃, and the viscosity of the reaction precursor slurry is easier to control in a reasonable range; after 5 consecutive periods of agitation (no intervening cessation of agitation), the reactive precursor slurry reached an optimal reaction state that produced the "elemental units Si-O4 and Al-O4 tetrahedra".
Heating the mould to 60-70 ℃, pouring the reaction precursor slurry stirred for 30 minutes into the mould, and shaking the mould for 2-3 minutes until no obvious bubbles emerge from the slurry. And (3) moving the mold to a curing box at 60 ℃, standing for 4 hours, raising the temperature by 10 ℃ every four hours, standing and curing for 12 hours, wherein the relative humidity in the curing box is 100 percent. Then raising the maintenance temperature by 90 ℃, reducing the relative humidity to 40 +/-5%, standing for 12 hours, and then demoulding. And (3) after demolding, placing the geopolymer product at 25 +/-5 ℃, and maintaining for more than 6 days in a ventilated environment until the geopolymer environment-friendly material is obtained. The curing temperature versus time curve is shown in FIG. 2.
The uniaxial compressive strength of the geopolymer products of the above four embodiments (examples 1, 2, comparative examples 1, 2) is shown in fig. 3.
As can be seen from FIG. 3, the molar Ratio of (K + Na)/(Al + Fe) of comparative example 1 satisfies the Mol Ratio 2, but OH-1/(Al + Fe) does not satisfy the Mol Ratio 2, and sufficient Si-O4 tetrahedra and Al-O4 tetrahedra cannot be excited, so that the geopolymer 3D frame cannot be sufficiently formed, and the strength is reduced, so that the uniaxial compressive strength of the material obtained by the scheme does not reach 30MPa after 7 days of curing. Similarly, in comparative example 2, the molar ratios of (K + Na)/(Al + Fe) and OH-1/(Al + Fe) do not satisfy the requirement of Mol Ratio 2, and the uniaxial compressive strength after 7 days of curing is only 16.7 MPa. While the examples 1 and 2 simultaneously meet all the requirements of Mol Ratio 1 and 2, and the uniaxial compressive strength of the material after 7-day curing exceeds 30 MPa; the compression strength of the baking-free bricks and the like prepared by the material is far beyond the average level of the common industry.
In addition, the thermal conductivity of the materials prepared in examples 1 and 2 is 0.1-0.2W/m.K, and the thermal conduction efficiency is very low, because the 3D network formed by Si-O4 and Al-O4 tetrahedrons is an amorphous disordered structure, the thermal conduction efficiency is very low, and the ordered structure of silicon oxide and aluminum oxide is mainly in the materials such as ceramic to be sintered, the thermal conduction efficiency is high, which is an important reason for the low thermal conduction efficiency of the material of the invention.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable to various fields of endeavor for which the invention may be embodied with additional modifications as would be readily apparent to those skilled in the art, and the invention is therefore not limited to the details given herein and to the embodiments shown and described without departing from the generic concept as defined by the claims and their equivalents.
Claims (12)
1. The geopolymer environment-friendly energy-saving material with river and lake sludge as a single raw material is characterized in that Na2SiO3 and KOH and/or NaOH solution are used as alkali activators, and the sludge is used as the single raw material, wherein the sludge used as the raw material is subjected to preliminary dehydration treatment, the water content of the sludge is 35% -50%, the water content is defined as the mass ratio of free water to solid matters in the sludge, the mass ratio of the Na2SiO3 to the solid matters in the sludge is 7.1% -29.7%, and the mass ratio of the KOH and/or NaOH to the solid matters in the sludge is 6.6% -28.9%.
2. The geo-polymer environment-friendly energy-saving material taking river and lake sludge as a single raw material as claimed in claim 1, is characterized in that: the total mass of the compounds of main elements Si, Al, Fe and Na in the sludge is not less than 75 percent of the solid content in the sludge.
3. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material is characterized by comprising the following steps of:
s1: drying the sludge;
s2: crushing and sieving;
s3: preparing a geopolymer reaction precursor slurry;
s4: forming and maintaining to obtain a finished product;
in S3, Na2SiO3 and KOH and/or NaOH solution are used as alkali activators, sludge is used as a single raw material, the two raw materials are mixed uniformly to form a mixture, and the molar ratio of OH-, Si, Na, K, Al and Fe in the mixture in a reaction system is controlled as follows:
the molar ratio is 1: si (Al + Fe) =1: 4.3-5.7;
the molar ratio is 2: (Na + K): (Al + Fe) =1 (0.5-1.5), OH-: Al + Fe) =1 (0.7-2.0).
4. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 3, is characterized in that: in S1, the moisture content of the sludge for drying is between 20 and 50 percent; the drying environment temperature is controlled between 105 ℃ and 110 ℃ and ventilation treatment is needed.
5. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 3, is characterized in that: in S2, the dried sludge prepared in S1 is crushed and then sieved through a 170-mesh sieve to obtain sludge particles.
6. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 3, is characterized in that: s3, placing the sludge in an oven at 45-65 ℃ and ensuring that the temperature of sludge particles is between 45-65 ℃; heating the stirrer container to 45-65 deg.C, stirring the sludge in the stirrer at 40-80 r/min; and slowly pouring the alkali activator solution into the sludge, continuously stirring for several minutes after the alkali activator solution is completely poured, then increasing the rotating speed to be not less than 100r/min, and continuously stirring for several minutes to fully mix the sludge and the alkali activator to obtain uniform geopolymer reaction precursor slurry A.
7. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 3, is characterized in that: putting the sludge into an oven at 50-60 ℃ to ensure that the temperature of sludge particles is between 50-60 ℃; heating the stirrer container to 60 ℃, and placing the sludge in a stirrer for stirring at the rotating speed of 60 r/min; and slowly pouring the alkali activator solution into the sludge, continuously stirring for 2 minutes after the alkali activator solution is completely poured, increasing the rotating speed to 150r/min, and continuously stirring for 3 minutes to fully mix the sludge and the alkali activator to obtain uniform geopolymer reaction precursor slurry A.
8. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 6, is characterized in that: stirring the uniform geopolymer reaction precursor slurry A at a stirring speed of not less than 200r/min for several minutes, then reducing the stirring speed to not more than 180r/min for several minutes, and forming a plurality of stirring cycles with high and low speeds matched to obtain the further-reacted geopolymer reaction precursor slurry B.
9. The method for preparing the geopolymer environment-friendly energy-saving material by taking river and lake sludge as a single raw material according to claim 8, is characterized in that: the low-speed stirring time is not shorter than 1/3 of the high-speed stirring time in each stirring period, the total time of each stirring period is not more than 10min, and the total stirring time is not less than 20 min.
10. The method for preparing the geopolymer environment-friendly energy-saving material by taking river and lake sludge as a single raw material according to claim 9, is characterized in that: stirring the uniform geopolymer reaction precursor slurry A, setting the stirring speed to 240r/min for stirring for 4 minutes, then reducing the stirring speed to 150r/min for stirring for 2 minutes to form a 6-minute stirring period with high and low speeds, and circulating for 5 stirring periods, wherein the total stirring time in the period is 30 minutes.
11. The preparation method of the geopolymer environment-friendly energy-saving material taking river and lake sludge as a single raw material according to claim 3, is characterized in that: s4, heating the mould to 60-70 ℃, pouring the stirred slurry of the chemical polymer reaction precursor into the mould, and vibrating for several minutes until no obvious bubbles are emitted from the slurry; moving the die to a curing box at 60-70 ℃, standing for 4 hours, raising the temperature by 10 ℃ every four hours, standing for curing for 12 hours, raising the curing temperature to 90-100 ℃, adjusting the relative humidity in the curing box to 40 +/-5%, standing for 12 hours, and then demolding; and (3) after demolding, placing the geopolymer product in a 25 +/-5 ℃ environment, and maintaining for 6 days or more in a ventilated environment.
12. The method for preparing the geopolymer environment-friendly energy-saving material by taking river and lake sludge as a single raw material according to claim 11, is characterized in that: and (3) moving the die to a curing box at the temperature of 60-70 ℃, standing for 4 hours, raising the temperature by 10 ℃ every four hours, and standing and curing for 12 hours, wherein the relative humidity in the curing box is 100%.
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