Low-carbon cementitious material, preparation method and application thereof

Abstract

The present application relates to a kind of low carbon cementitious material and its preparation method and application, the preparation method includes the following steps: raw material pretreatment, mixing, reaction, filtration drying, mixing calcination and adding reinforcing agent.The present application prepares cementitious material by synergistically disposing municipal solid waste incineration bottom ash, municipal solid waste incineration fly ash, electrolytic manganese residue and regenerated micro powder, realizes the unity of solid waste resource, almost zero dissolution of heavy metal, cementitious material high performance and low carbon.

Description

Technical Field

[0001] This invention relates to the field of cementitious materials technology, and in particular to a low-carbon cementitious material, its preparation method, and its application. Background Technology

[0002] With the acceleration of urbanization and the large-scale development of industry, the annual emissions of solid waste such as municipal solid waste incineration bottom ash (MSWIBA), municipal solid waste incineration fly ash (MSWIFA), electrolytic manganese slag (EMR), and recycled micronized powder (RP) are showing a continuous upward trend. Statistics show that my country generates over 10 million tons of MSWIBA and MSWIFA annually from municipal solid waste incineration, over 5 million tons of EMR, and over 100 million tons of recycled micronized powder (RP). These solid wastes generally contain heavy metals such as chromium, lead, copper, mercury, and zinc, as well as soluble harmful components. If traditional stockpiling or landfill methods are used, it easily leads to heavy metal pollution of soil and groundwater seepage pollution, and occupies a large amount of land resources. Meanwhile, traditional silicate cement, as the mainstream cementing material, requires high-temperature calcination above 1200℃ during production, emitting approximately 0.8 to 1.0 tons of CO2 per ton of cement, accounting for 5% to 7% of global industrial carbon emissions, which does not meet the requirements of "dual-carbon" development.

[0003] Existing solid waste resource utilization technologies mostly focus on using waste as concrete filler or auxiliary cementitious materials after simple treatment (such as screening and grinding). They fail to achieve the co-processing of multiple solid wastes and high-performance utilization, resulting in low resource utilization rates. Therefore, developing a method for preparing cementitious materials that can co-process multiple solid wastes, efficiently solidify heavy metals, consume low energy, and produce high-performance products is crucial for solving solid waste pollution and promoting the development of low-carbon building materials. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a method for preparing a low-carbon cementitious material, characterized by comprising the following steps: Pretreatment: Take municipal solid waste incineration bottom ash (MSWIBA), weather it, remove large-particle impurities, crush it, and obtain municipal solid waste incineration bottom ash powder; take electrolytic manganese slag (EMR), crush it, and obtain electrolytic manganese slag powder. Mixing: Mix municipal solid waste incineration fly ash (MSWIFA) with municipal solid waste incineration bottom ash powder to obtain dry powder mixture 1; mix municipal solid waste incineration fly ash with electrolytic manganese slag powder to obtain dry powder mixture 2; Reaction: Take dry powder mixture 1, add water, add reaction promoter, stir to react and obtain wet mixture 1; take dry powder mixture 2, add water, stir to obtain wet mixture 2; the reaction promoter includes sodium hydroxide, calcium oxide and magnesium oxide, and the mass ratio of sodium hydroxide:calcium oxide:magnesium oxide is 1:(1~3):(1~3); Filtration and drying: After removing impurities, the wet mixture 1 is filtered and dried to obtain dry mud cake 1; the wet mixture 2 is filtered and dried to obtain dry mud cake 2. Mixed calcination: Take dried mud cake 1, mix it with regenerated micro powder (RP) and kaolinite, calcine, and cool to obtain the cooled product; Adding reinforcing agent: Take the cooled product and add reinforcing agent 1 to mix, ball mill and obtain low carbon cementitious material powder, add reinforcing agent 2 to the low carbon cementitious material powder, mix to obtain low carbon cementitious material; the reinforcing agent 1 includes at least one of dried mud cake 2, blast furnace slag, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and sodium hydroxide crystals.

[0005] In one embodiment, the weathering time in the pretreatment step is 3 to 6 months, and the particle size of the large-diameter impurities is >5 mm.

[0006] In one embodiment, in the pretreatment step, the particle size of the municipal solid waste incineration bottom ash powder is ≤5mm, and the particle size of the electrolytic manganese slag powder is ≤5mm.

[0007] In one embodiment, the dry powder mixture 1 has a mass ratio of municipal solid waste incineration fly ash to municipal solid waste incineration bottom ash powder of (0.2~0.8):1; In the dry powder mixture 2, the mass ratio of the municipal solid waste incineration fly ash to the electrolytic manganese slag powder is (0.2~0.8):1.

[0008] In one embodiment, in the reaction step, the amount of water added to the dry powder mixture 1 is 100-300% of the mass of the dry powder mixture 1; The amount of the reaction accelerator added is 0.5-5% of the mass of the dry powder mixture 1; The temperature of the stirring reaction is 60~100℃; The amount of water added to the dry powder mixture 2 is 200-400% of the mass of the dry powder mixture 2.

[0009] In one embodiment, the reaction promoter includes sodium hydroxide (NaOH), calcium oxide (CaO), and magnesium oxide (MgO) in a mass ratio of 1:2:1.

[0010] In one embodiment, during the reaction step, the stirring rate of the stirring reaction is 20~100 r / min, and the stirring reaction time is 30 min~2 h.

[0011] In one embodiment, during the reaction step, the wet mixture 2 is obtained by stirring under oxygen-rich conditions for 2 to 6 hours.

[0012] In one embodiment, during the filtration and drying step, the drying temperature of the dried mud cake 1 is 60~110℃, and the drying temperature of the dried mud cake 2 is 80~105℃.

[0013] In one embodiment, in the mixing and calcination step, the amount of regenerated micro powder added is 5-100% of the mass of the dried mud cake 1; the amount of kaolinite added is 2-50% of the mass of the dried mud cake 1.

[0014] In one embodiment, the mixing time in the mixing and calcination step is 10-15 minutes.

[0015] In one embodiment, in the mixing and calcining step, the calcination temperature is 550~750℃ and the calcination time is 1~3 hours.

[0016] In one embodiment, the calcination temperature in the mixing and calcination step is 650~750℃.

[0017] In one embodiment, the calcination in the mixing and calcination step is calcination in an environment with an oxygen concentration ≥25%.

[0018] In one embodiment, in the step of adding the reinforcing agent, the amount of dried sludge cake 2 added is 5-50% of the mass of the cooled product, the amount of blast furnace slag added is 20-200% of the mass of the cooled product, the amount of triethanolamine added is 0.01-0.5% of the mass of the cooled product, the amount of triisopropanolamine added is 0.01-0.5% of the mass of the cooled product, the amount of diethanol monoisopropanolamine added is 0.01-0.5% of the mass of the cooled product, and the amount of sodium hydroxide crystals added is 0.5-10% of the mass of the cooled product.

[0019] Understandably, the amounts of the above-mentioned dried mud cake 2, blast furnace slag, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and sodium hydroxide crystals are the amounts used when each reinforcing agent raw material is used alone or in combination.

[0020] In one embodiment, during the step of adding the reinforcing agent, the ball-to-material ratio in the ball milling is (1:5) to (1:20), the ball milling rate is 400 to 1000 r / min, the ball milling time is 30 to 60 min, and the powder obtained after ball milling has a particle size ≤100 μm and a specific surface area ≥500 m². 2 / kg.

[0021] In one embodiment, in the step of adding the reinforcing agent, the amount of reinforcing agent 2 added is 0.1% to 1% of the mass of the low-carbon cementitious material powder; The reinforcing agent 2 includes at least one of polycarboxylate superplasticizer, fruit acid, and fructose.

[0022] In one embodiment, the mixing time in the step of adding the reinforcing agent is 5 to 10 minutes.

[0023] A second aspect of the present invention also provides a low-carbon cementitious material obtained by the above preparation method.

[0024] A third aspect of the present invention also provides a low-carbon cementitious material obtained by the above preparation method or the application of the above low-carbon cementitious material in the preparation of low-carbon cementitious material-based concrete.

[0025] In addition, the present invention also provides a low-carbon cementitious material-based concrete, comprising the low-carbon cementitious material obtained by the above preparation method or the above-mentioned low-carbon cementitious material.

[0026] Compared with the prior art, the present invention has the following beneficial effects: (1) Significant effect of co-processing of solid waste: the co-utilization of four types of solid waste, namely MSWIBA, MSWIFA, EMR and RP, has been achieved; (2) Outstanding advantages in low carbon and environmental protection: The calcination temperature is only 550~750℃, which reduces energy consumption by more than 50% and carbon emissions by 40%~50% compared with traditional cement; (3) Improved product performance: The curing rate of harmful metals is ≥95%, and the 28-day compressive strength of concrete is ≥40MPa. It can be used in high-performance concrete projects such as high-rise buildings and bridges. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the preparation process for low-carbon cementitious materials. Detailed Implementation

[0028] To overcome the shortcomings of existing technologies, such as "low resource utilization, low heavy metal solidification rate, and high energy consumption and carbon emissions," this invention provides a method for preparing low-carbon cementitious materials, achieving the unity of solid waste resource utilization, near-zero heavy metal leaching, and high-performance and low-carbon cementitious materials.

[0029] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0031] Unless otherwise specified, all reagents, materials, and equipment used in this embodiment are commercially available; unless otherwise specified, all test methods are conventional test methods in this field.

[0032] Example This embodiment provides a method for preparing a low-carbon cementitious material, including the following steps: 1. Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 3-6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. 2. The MSWIBA and electrolytic manganese slag (EMR) obtained in step 1 are crushed using a blade crusher to obtain powder with a particle size ≤ 5 mm. Generally, the oxide compositions of MSWIBA and EMR are shown in Table 1 below: Table 1

[0033] 3. Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step 2 at a mass ratio of 0.2~0.8:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step 2 at a mass ratio of 0.2~0.8:1 to obtain dry powder mixture 2. Generally, the oxide composition of MSWIFA is shown in Table 2 below: Table 2

[0034] The mixing principle and technical effects of dry powder mixtures 1 and 2 are as follows: MSWIFA is a high-alkalinity, high-chlorine, and high-calcium component that provides the alkalinity and calcium source required for the reaction.

[0035] MSWIBA / EMR is a silicon-aluminum / manganese matrix that provides the active components.

[0036] A ratio of 0.2 to 0.8 indicates sufficient alkalinity, uniform reaction, and controllable chlorine content.

[0037] Technical benefits: Sufficient alkali activation and large amount of silicon and aluminum dissolution; avoids excessive alkali leading to alkali bloom and poor stability in the later stage.

[0038] 4. Add water to dry powder mixture 1 (the amount of water is 100%~300% of the mass of dry powder), and stir at 20~100 r / min at 60~100℃ for 30 minutes to 2 hours to obtain wet mixture 1. During stirring, the suspension is fully exposed to air. This step has the following technical advantages: ① It fully utilizes the alkalinity of oxides and basic chlorides in MSWIFA, allowing the metallic elements (mainly aluminum) in MSWIFA to react under heating conditions to generate aluminates and release hydrogen gas, effectively avoiding the problem of poor volume stability caused by hydrogen generation during the gelation reaction; ② It fully converts the oxides and basic chlorides in MSWIFA into hydroxides, avoiding the problem of poor volume stability caused by the expansion of oxides by water absorption during the gelation material reaction; ③ MSWIFA itself contains very low silicon and aluminum activity. Activating it with MSWIFA can pre-generate gelation products before the hydration reaction of low-carbon gelation materials. These gelation products can be converted into dehydrated gel phases in step 7. These gels can react rapidly with water, providing strength.

[0039] After adding water to the dry powder mixture 1, a reaction promoter needs to be added, which is composed of NaOH, CaO, and MgO in a specific ratio (1:1~3:1~3, with the component mass percentage being 0.5%~5% of the dry powder mixture 1). When NaOH, CaO, and MgO dissolve in water, they all release a large number of hydroxide ions, promoting the dissolution of active components such as SiO2 and Al2O3 in the solid waste, and initially forming various gelling products, such as hydrotalcite, hydrated calcium silicate (aluminate), hydrated sodium aluminosilicate, zeolite, and ettringite phases. An alkaline environment allows heavy metals in the solid waste to dissolve and then form hydroxide precipitates under heating. Simultaneously, the aforementioned gelling products can encapsulate the dissolved heavy metals through "physical encapsulation" or adsorb them onto their surface through "chemical adsorption." Based on these three effects, the heavy metals in the solid waste can be initially solidified / stabilized.

[0040] In addition, water is added to the dry powder mixture 2 obtained in step 3, with the amount of water being 200%~400% of the total mass of the dry powder. The mixture is stirred for 2~6 hours at room temperature and under oxygen-enriched conditions to obtain wet mixture 2. This step has the following technical advantages: ① The alkalinity of MSWIFA fully solidifies the manganese ions in the EMR, forming a flocculent precipitate of manganese hydroxide and releasing ammonia gas, effectively avoiding the volume instability of the cementitious system caused by ammonia release during hardening; ② Under oxygen-enriched conditions, the generated manganese hydroxide is rapidly oxidized to manganese dioxide. Compared to untreated EMR, this method can effectively prevent the oxidation and dehydration of manganese hydroxide during the hydration reaction from causing a loose porous structure in the hardened low-carbon cementitious material.

[0041] The reaction principles of each component are as follows: A. Reaction principle in dried mud cake 1 (1) Digestion reaction of elemental aluminum The reaction proceeds rapidly in a strongly alkaline environment provided by NaOH and CaO. 2Al+2NaOH+2H2O→2NaAlO2+3H2↑ 2Al+Ca(OH)2+2H2O→Ca(AlO2)2+3H2↑ (2) Alkali-activated reaction 1) Rapid dissolution of NaOH provides high alkali SiO₂ + 2NaOH → Na₂SiO₃ + H₂O Al₂O₃ + 2NaOH → 2NaAlO₂ + H₂O The dissolved sodium silicate and sodium aluminate undergo a condensation reaction under alkaline conditions to form an amorphous NASH gel. Na₂SiO₃ + NaAlO₂ + H₂O → Na₂O·Al₂O₃·SiO₂·nH₂O (NASH gel) 2) CaO hydration provides Ca 2+ With medium-strong alkali CaO + H₂O → Ca(OH)₂ xCa(OH)2 + ySiO2 → xCaO·ySiO2·nH2O (hydrated calcium silicate) xCa(OH)2 + yAl2O3 → xCaO·yAl2O3·nH2O (Calcium aluminate hydrate) Ca 2+ It enters the NASH structure, forming a higher strength and more stable CNASH gel: xCa(OH)2 + Na2O·Al2O3·SiO2·nH2O → CaO·Na2O·Al2O3·SiO2·mH2O (CNASH gel) 3) MgO hydration participates in alkali activation to form hydrated magnesium aluminate carbohydrate; Mg(OH)2 provides a weakly to moderately alkaline environment, participates in the bonding of silicon and aluminum components, and significantly enhances the curing ability of heavy metals: MgO + H₂O → Mg(OH)₂ Mg(OH)2 + Al2O3 + CO3 2- +H₂O→Mg x Al γ (OH) 2x+3γ -2 (CO3)·mH2O (3) Heavy metal solidification and precipitation reaction Pb 2+ +2OH - →Pb(OH)2↓ Cr 3+ +3OH - →Cr(OH)3↓ Cu 2+ +2OH - →Cu(OH)2↓ Zn 2+ +2OH - →Zn(OH)2↓ Hg 2+ +2OH - →Hg(OH)2↓ Mg(OH)₂ and hydrotalcite-like materials can stabilize heavy metals through interlayer intercalation, surface adsorption, and co-precipitation. CASH gels exhibit adsorption, ion exchange, and physical encapsulation effects on heavy metal ions.

[0042] B. Reaction principle in dried mud cake 2 (1) Manganese ion fixation and oxidation MSWIFA provides alkalinity, enabling Mn 2+ Mn(OH)2 flocs are generated: Mn 2+ +2OH - →Mn(OH)2↓ Rapid oxidation to MnO2 under oxygen-rich conditions avoids subsequent volume expansion and loose structure. 2Mn(OH)2 + O2 → 2MnO2 + 2H2O (2) Ammonia nitrogen removal An alkaline environment promotes the conversion of ammonium ions in EMR into NH3, which then escapes, eliminating odor and volume instability factors. NH4 + +OH - →NH3↑+H2O 5. Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 1 to 2.5 hours. Use the density difference to skim off the light impurities floating on the top (such as plastic fragments, organic matter, and light substances that have not been removed). 6. Filter the wet mixture 1 and 2 using a filter press to obtain mud cakes 1 and 2 with a moisture content of 30%~50% respectively; put mud cakes 1 and 2 into a forced-air drying oven and dry them at 60~110℃ and 80~105℃ respectively to constant weight to obtain dried mud cakes 1 and 2. 7. Add 5% to 100% of the mass of dried mud cake 1, RP (screened micro powder produced from recycled aggregate of waste concrete), and 2% to 50% of the mass of dried mud cake 1, into a mixer and mix for 10 to 15 minutes to ensure uniform dispersion. This step has the following technical advantages: ① RP and kaolinite supplement the dried mud cake with highly active silica and alumina. With the help of low-temperature calcination, not only can a large amount of active silica and alumina be generated, but also a large amount of calcium aluminosilicate, dicalcium silicate crystals, calcium aluminate crystals, and dehydrated cementitious phases can be generated. The above substances can be rapidly hydrated, enhancing the performance of low-carbon cementitious materials; ② After the dried mud cake 1 is combined with RP and kaolinite, a synergistic effect is formed, and the whole can have a high calcium content, which is conducive to the generation of highly active products such as calcium aluminosilicate, dicalcium silicate crystals, and calcium aluminate crystals during low-temperature calcination, and reduces the generation of low-hydration active products.

[0043] Generally, the oxide composition of RP is shown in Table 3 below: Table 3

[0044] 8. The mixture is fed into a muffle furnace and calcined at 550~750℃ (far lower than the calcination temperature of traditional cement) for 1~3 hours in an oxygen-rich environment (oxygen concentration ≥25%). This effectively removes residual organic matter and light substances brought about by the incorporation of MSWIFA and MSWIBA, activates potential active sites in solid waste, and rapidly dehydrates existing reaction products to form new reaction raw materials. After calcination, the mixture is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥10℃ / min), which can reduce the degree of crystallization of the reaction products, accelerate the product reaction rate, and reduce the activity reduction caused by CaCO3 formation. The reaction principle of the calcination stage is as follows: (1) hydrated calcium aluminosilicate dehydrates to form highly active aluminosilicate: xCaO·ySiO2·zAl2O3·nH2O→xCaO·ySiO2·zAl2O3+nH2O↑ (2) CNASH gel dehydration CaO·Na2O·Al2O3·SiO2·mH2O→CaO·Na2O·Al2O3·SiO2+mH2O↑ (3) NASH gel dehydration Na2O·Al2O3·SiO2·nH2O→Na2O·Al2O3·SiO2+nH2O↑ (4) Dehydration of hydrated magnesium aluminate carbohydrate and activation of magnesium-based precursor Mg x Al γ (OH) 2x+3γ -2 (CO3)·mH2O→Mg x Al γ O( 2x+1.5γ -1 (CO3) 0.5 +mH2O↑ (5) Dehydration and decomposition of AFt (ettringite) 3CaO·Al2O3·3CaSO4·32H2O→3CaO·Al2O3·3CaSO4+32H2O↑ (6) Dehydration and decomposition of calcium monoaluminate 3CaO·Al2O3·CaCO3·11H2O→3CaO·Al2O3·CaCO3+11H2O↑ (7) Dehydration and decomposition of calcium hemialuminate 3CaO·Al2O3·0.5CaCO3·12H2O→3CaO·Al2O3·0.5CaCO3+12H2O↑ 9. Add reinforcing agent 1 to the cooling product to optimize the workability and mechanical properties of the cementitious material; reinforcing agent 1 is any one or more of the following: dried mud cake 2 (pretreated EMR-MSWIFA mud cake), blast furnace slag, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and sodium hydroxide crystals. The mass ratio of each component to the mass of the cooling product is as follows: 5%~50% dried mud cake 2, 20%~200% blast furnace slag, 0.01%~0.5% triethanolamine, 0.01%~0.5% triisopropanolamine, 0.01%~0.5% diethanol monoisopropanolamine, and 0.5%~10% NaOH crystals; 10. Feed the mixture into a planetary ball mill and mill at a ball-to-material ratio of 1:5 to 1:20 for 30 to 60 minutes at 400 to 1000 r / min, controlling the powder particle size to be ≤100 μm and the specific surface area to be ≥500 m². 2 / kg; 11. Spray reinforcing agent 2 (one or more of polycarboxylate superplasticizer, fruit acid, and fructose, added at 0.1% to 1% of the mass of the low-carbon cementitious material powder) into the powder, mix for 5 to 10 minutes, and obtain the low-carbon cementitious material. 12. Add water at a water-cement ratio of 0.4~0.5, mix with sand and coarse aggregate, and pour into low-carbon cementitious material-based concrete specimens with dimensions of 150mm long × 150mm wide × 150mm high. After demolding, place the specimens in an environment with a temperature of 20±2℃ and a relative humidity of ≥95% for 28 days, and then test their mechanical properties. After pouring and curing, test the leaching amount of harmful elements in the same water-cement ratio neat cement paste.

[0045] The present invention will be further described in detail below through specific embodiments. Performance tests were conducted according to national standards (compressive strength: GB / T 17671-1999; heavy metal solidification rate: HJ 557-2010; cement stability: GB / T 1346-2024). The heavy metal solidification rate is calculated as: (leachation amount of heavy metals from the solid waste itself / leaching amount of heavy metals from the solidified cement slurry) × 100. The results of the 28-day compressive strength, heavy metal solidification rate, and cement stability of the concrete are shown in Table 4 (data are rounded to integers).

[0046] Example 1 The specific steps and parameters used in this embodiment are as follows: (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. The formulation principle and technical effects of enhancer 1 are as follows: 1) Dry mud cake 2 Formulation principle: Provides a certain amount of alkalinity, sulfate components, and active silicon-aluminum to form a synergistic effect with the calcined products.

[0047] Technical benefits: Further improves the utilization rate of solid waste; supplements active components.

[0048] 2) Blast furnace slag Proportioning principle: Highly active water-quenched slag provides the system with potential hydraulic properties and pozzolanic activity, supplementing the strength of the calcined products in the later stages.

[0049] Technical effects: Significantly improves 7d and 28d strength; improves pore structure and density; enhances impermeability and durability.

[0050] Proportioning logic: When the dosage is too low, there is less highly active silicon and aluminum in the system, resulting in insufficient strength and poor stability in the middle and later stages; when the dosage is too high, there is a lack of alkaline substances and fast-reacting substances (dehydration phase), and the overall strength (especially the early stage strength) will decrease.

[0051] 3) Triethanolamine / Triisopropanolamine / Diethanol Monoisopropanolamine Formulating principle: Organic amines are dispersing, coagulating, and reinforcing components that can reduce interparticle friction, promote hydration, and accelerate mineral dissolution.

[0052] Technical effects: Improves fluidity; promotes early hydration; increases strength.

[0053] 4) NaOH crystals Formulation principle: Provide an activating alkaline environment to continuously activate the silicon and aluminum activity of slag and calcined products.

[0054] Technical effects: Ensures continuous hydration; improves the density and strength of the cementitious system.

[0055] (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0056] Example 2 The specific steps and parameters used in this embodiment are as follows: (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.1:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0057] Example 3 The specific steps and parameters used in this case are as follows: (1) The bottom ash (MSWIBA) from municipal solid waste incineration is weathered for 6 months. Plastics (particle size > 5mm) are manually removed and large-particle metals are separated by magnetic attraction to avoid equipment blockage or wear in subsequent processes. A blade crusher is used to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 20% RP and 5% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0058] Example 4 The specific steps and parameters used in this case are as follows: (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 5% dried mud cake 2, 50% blast furnace slag, 0.01% triethanolamine, 0.01% triisopropanolamine, 0.01% diethanol monoisopropanolamine, and 2% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0059] Example 5 The specific steps and parameters used in this case are as follows: (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 550°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0060] Example 6 The specific steps and parameters used in this case are as follows: (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to the dry powder mixture 1 (the amount of water is 300% of the mass of the dry powder), and add reaction promoter (0.5% NaOH, 1% CaO, 0.5% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0061] Example 7 (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; mix the municipal solid waste incineration fly ash (MSWIFA) and the EMR obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100 r / min for 2 hours at room temperature, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0062] Example 8 (1) Weather the bottom ash (MSWIBA) of municipal solid waste incineration for 6 months, manually remove plastic (particle size > 5mm) and magnetically separate large-particle metal to avoid equipment blockage or wear in subsequent processes, and use a blade crusher to crush MSWIBA and EMR to a particle size ≤ 5mm. (2) The MSWIBA and electrolytic manganese slag (EMR) obtained in step (1) are crushed using a blade crusher to obtain powder with a particle size ≤5mm. (3) Mix the municipal solid waste incineration fly ash (MSWIFA) and the MSWIBA obtained in step (2) at a mass ratio of 0.3:1 to obtain dry powder mixture 1; do not add MSWIFA to the EMR, and the EMR is still named dry powder mixture 2; (4) Add water to dry powder mixture 1 (the amount of water is 300% of the mass of dry powder), and add reaction promoter (1% NaOH, 2% CaO, 1% MgO); Stir at 100°C and 100 r / min for 2 hours, ensuring the suspension is fully exposed to air during stirring; In addition, water was added to the dry powder mixture 2 obtained in step (3), the amount of water being 400% of the total mass of the dry powder, and stirred for 6 hours at room temperature and oxygen-enriched conditions to obtain wet mixture 2. (5) Transfer the stirred wet mixture 1 to the sedimentation tank and let it stand for 2 hours. Use the density difference to skim off the light impurities floating on the top. (6) The wet mixture 1 and 2 were filtered by a filter press to obtain mud cake 1 and 2 respectively. Mud cake 1 and 2 were placed in a forced-air drying oven and dried at 105℃ and 80℃ respectively to constant weight to obtain dried mud cake 1 and 2. (7) After the dried mud cake 1 is crushed and dispersed by a hammer crusher, it is fed into a mixer together with 60% RP and 20% kaolinite and mixed for 10 minutes to ensure uniform dispersion; (8) The mixture is fed into a muffle furnace and calcined at 750°C for 2 hours in an oxygen concentration of 25%. After calcination, it is rapidly cooled to room temperature by an air-cooling system (cooling rate ≥ 10°C / min). (9) Add reinforcing agent 1 to the cooling product to optimize the working performance and mechanical properties of the cementitious material. The mass ratio of each component of reinforcing agent 1 to the mass of the cooling product is as follows: 20% dried mud cake 2, 180% blast furnace slag, 0.03% triethanolamine, 0.03% triisopropanolamine, 0.03% diethanol monoisopropanolamine, and 5% NaOH crystals. (10) Put the mixture into a planetary ball mill and mill it for 45 minutes at 450 r / min at a ball-to-material ratio of 1:10. (11) Spray reinforcing agent 2 (0.3% polycarboxylate superplasticizer, 0.1% fruit acid, 0.1% fructose) into the powder, mix for 10 minutes, and obtain low-carbon cementitious material; (12) Under the conditions of water-cement ratio of 0.45, bone glue ratio of 4, and coarse-fine aggregate mass ratio of 1.35, low-carbon cementitious material-based concrete specimens with dimensions of 150 mm long × 150 mm wide × 150 mm high were prepared. After the specimens were demolded, they were placed in an environment with a temperature of 20 ± 2℃ and a relative humidity of ≥ 95% for 28 days. Then, their mechanical properties were tested. After the same water-cement ratio of the neat cement paste was cast and cured, its harmful element leaching amount was tested.

[0063] Comparative Example 1 (42.5 level OPC) Cement concrete was prepared based on 42.5 grade Conch ordinary Portland cement under the following conditions: water-cement ratio (ratio of mixing water to cement by mass) = 0.45, aggregate-cement ratio (ratio of aggregate to cement by mass) = 4, and coarse-fine aggregate mass ratio (coarse aggregate mass: fine aggregate mass) = 1.35. After being poured, molded and demolded, the concrete was cured under standard conditions (temperature 20±2℃, relative humidity ≥95%) for 28 days, and its compressive strength value was tested.

[0064] Implementation effect evaluation The results of volume stability, 28-day strength, and heavy metal curing rate for the comparative and example examples are shown in Table 4: Table 4

[0065] The 28-day compressive strength of Example 1 reached 43 MPa, which is higher than that of traditional 42.5 grade ordinary silicate cement, fully demonstrating that the low-carbon cementitious material prepared by the present invention can achieve the goal of high performance.

[0066] Example 2—Effect of MSWIFA to MSWIBA mass ratio: Reducing the mass ratio of MSWIFA to MSWIBA to 0.1:1 reduced the strength to 36 MPa, the cement stability was qualified, and the curing rate of chromium (Cr) and zinc (Zn) was slightly lower than in Example 1, indicating that MSWIFA has a positive effect on improving strength and heavy metal curing efficiency in the synergistic reaction.

[0067] Example 3—Impact of RP and Kaolinite Dosage: Reducing the dosage of RP and kaolinite significantly reduced the strength to 27 MPa, while the cement stability was satisfactory. The curing rates of chromium (Cr), lead (Pb), mercury (Hg), and zinc (Zn) were lower than in Example 1, confirming the key role of RP and kaolinite in reducing the internal porosity of cementitious materials and enhancing their reactivity.

[0068] Example 4—Influence of Reinforcing Agent Proportion: Reducing the amount of core components such as EMR and blast furnace slag in reinforcing agent 1 resulted in qualified cement stability, but the strength was reduced to 22 MPa. The curing rates of chromium (Cr), lead (Pb), copper (Cu), mercury (Hg), and zinc (Zn) were significantly lower than in Example 1, highlighting the reinforcing effect of the reinforcing agent on mechanical and curing / stabilization properties.

[0069] Example 5—Effect of Calcination Temperature: When the calcination temperature was reduced from 750℃ to 550℃, the strength dropped sharply to 19MPa. The cement stability was qualified. The curing rates of chromium (Cr), lead (Pb), copper (Cu), mercury (Hg), and zinc (Zn) were significantly lower than those in Example 1. This indicates that although low-temperature calcination can reduce energy consumption, it is necessary to control a reasonable temperature range (preferably 650~750℃) to balance energy consumption and strength.

[0070] Example 6—Influence of Reaction Accelerator: Reducing the amount of reaction accelerator resulted in a decrease in strength to 37 MPa compared to Example 1. The cement stability was satisfactory, but the strength and chromium (Cr) and lead (Pb) curing rates were slightly lower than in Example 1, indicating that the dosage of reaction accelerator has a certain influence on the performance of low-carbon cementitious materials.

[0071] Example 7—Effect of heat pretreatment of MSWIFA-MSWIBA mixture: After canceling the heat pretreatment, the strength decreased to 39 MPa compared to Example 1, the cement stability was unqualified, while the heavy metal curing rate was almost unaffected. This shows that heat pretreatment can improve the stability and mechanical properties of low-carbon cementitious materials.

[0072] Example 8—Effect of MSWIFA pretreatment on EMR: After canceling the MSWIFA pretreatment of EMR, compared with Example 1, the strength decreased to 36 MPa, the cement stability was unqualified, and the heavy metal curing rate was almost unaffected. This shows that MSWIFA pretreatment of EMR can improve the stability and mechanical properties of low carbon cementitious materials.

[0073] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0074] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for preparing a low-carbon cementitious material, characterized in that, Includes the following steps: Pretreatment: Take municipal solid waste incineration bottom ash, weather it, remove large-particle impurities, crush it, and obtain municipal solid waste incineration bottom ash powder; take electrolytic manganese slag, crush it, and obtain electrolytic manganese slag powder. Mixing: Take municipal solid waste incineration fly ash and municipal solid waste incineration bottom ash powder and mix them to obtain dry powder mixture 1; take municipal solid waste incineration fly ash and electrolytic manganese slag powder and mix them to obtain dry powder mixture 2; Reaction: Take dry powder mixture 1, add water, add reaction promoter, stir to react and obtain wet mixture 1; take dry powder mixture 2, add water, stir to obtain wet mixture 2; the reaction promoter includes sodium hydroxide, calcium oxide and magnesium oxide, and the mass ratio of sodium hydroxide:calcium oxide:magnesium oxide is 1:(1~3):(1~3); Filtration and drying: After removing impurities, the wet mixture 1 is filtered and dried to obtain dry mud cake 1; the wet mixture 2 is filtered and dried to obtain dry mud cake 2. Mixed calcination: Take dried mud cake 1, mix it with regenerated micro powder and kaolinite, calcine, and cool to obtain the cooled product; Adding reinforcing agent: Take the cooled product and add reinforcing agent 1 to mix, ball mill and obtain low carbon cementitious material powder, add reinforcing agent 2 to the low carbon cementitious material powder, mix to obtain low carbon cementitious material; the reinforcing agent 1 includes at least one of dried mud cake 2, blast furnace slag, triethanolamine, triisopropanolamine, diethanol monoisopropanolamine, and sodium hydroxide crystals.

2. The preparation method according to claim 1, characterized in that, In the dry powder mixture 1, the mass ratio of municipal solid waste incineration fly ash to municipal solid waste incineration bottom ash powder is (0.2~0.8):1; In the dry powder mixture 2, the mass ratio of the municipal solid waste incineration fly ash to the electrolytic manganese slag powder is (0.2~0.8):

1.

3. The preparation method according to claim 1, characterized in that, In the reaction step, the amount of water added to the dry powder mixture 1 is 100-300% of the mass of the dry powder mixture 1; The amount of the reaction accelerator added is 0.5-5% of the mass of the dry powder mixture 1; The temperature of the stirring reaction is 60~100℃; The amount of water added to the dry powder mixture 2 is 200-400% of the mass of the dry powder mixture 2.

4. The preparation method according to claim 1, characterized in that, In the mixing and calcination step, the amount of regenerated micro powder added is 5-100% of the mass of the dried mud cake 1; the amount of kaolinite added is 2-50% of the mass of the dried mud cake 1.

5. The preparation method according to claim 1, characterized in that, In the mixing and calcining step, the calcination temperature is 550~750℃, and the calcination time is 1~3 hours.

6. The preparation method according to claim 1, characterized in that, In the step of adding the reinforcing agent, the amount of dried sludge cake 2 added is 5-50% of the mass of the cooled product, the amount of blast furnace slag added is 20-200% of the mass of the cooled product, the amount of triethanolamine added is 0.01-0.5% of the mass of the cooled product, the amount of triisopropanolamine added is 0.01-0.5% of the mass of the cooled product, the amount of diethanol monoisopropanolamine added is 0.01-0.5% of the mass of the cooled product, and the amount of sodium hydroxide crystals added is 0.5-10% of the mass of the cooled product.

7. The preparation method according to claim 1, characterized in that, In the step of adding the reinforcing agent, the amount of reinforcing agent 2 added is 0.1% to 1% of the mass of the low-carbon cementitious material powder; The reinforcing agent 2 includes at least one of polycarboxylate superplasticizer, fruit acid, and fructose.

8. The low-carbon cementitious material obtained by the preparation method according to any one of claims 1-7.

9. The application of the low-carbon cementitious material obtained by the preparation method according to any one of claims 1-7 or the low-carbon cementitious material according to claim 8 in the preparation of low-carbon cementitious material-based concrete.

10. A low-carbon cementitious material-based concrete, characterized in that, The low-carbon cementitious material obtained by the preparation method according to any one of claims 1-7 or the low-carbon cementitious material according to claim 8.

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