A concrete activator based on inorganic solid waste and its preparation method

Abstract

The present invention relates to the technical field of building materials, and specifically to a concrete activator based on inorganic solid waste and a preparation method thereof. The present invention combines high-silicon solid waste with modified composite enzyme microcapsules for the first time to form a "solid waste base material-enzyme catalysis" composite activation system, and the raw material cost is reduced compared with traditional processes. Moreover, through the synergy of alkali activation and enzyme catalysis, the compressive strength of concrete is improved. The solid waste consumption per ton of the activator provided by the present invention reaches 160-240 kg, which is 30% higher than that of traditional processes, thus achieving "waste treatment with waste". In addition, the compressive strength and flexural strength of concrete prepared by the activator of the present invention are improved, no waste residue is discharged during the production process, energy consumption is significantly reduced compared with the dry process, and carbon emissions per unit product are reduced, thus breaking through the performance bottleneck of existing activators and providing a new technical path for solid waste-based building materials.

Description

Technical Field

[0001] The present invention relates to the technical field of building materials, and in particular to a concrete activator based on inorganic solid waste and a preparation method thereof. Background Art

[0002] In the building materials sector, the treatment of high-silicon inorganic solid waste (such as waste glass, tailings, and fly ash) has long been an industry challenge. Currently, the primary treatment method for this type of solid waste is landfill, with only a small amount used in building materials production. This treatment and utilization method is associated with significant pollution, high energy consumption, and low added value.

[0003] The main component of concrete reinforcement (activator) is water glass, and its current production processes are divided into two types: dry and wet methods. The dry method uses high-purity quartz sand as raw material and requires sintering at a high temperature of 1400°C. This is associated with high raw material costs, complex processes, high energy consumption, and severe environmental pollution. The wet method heats and pressurizes an aqueous solution of caustic soda (NaOH) or potassium hydroxide (KOH) and quartz sand in a reactor, then filters and concentrates it to produce liquid water glass. While this method offers advantages such as simplicity, low energy consumption, low labor intensity, high product quality, and low pollution, it also faces challenges such as the difficulty in obtaining high-purity quartz sand raw materials, the high price, and the generation of filter residue emissions. For example, the existing wet method of water glass production not only relies on high-purity quartz sand as raw material, resulting in high costs, but also produces filter residue that pollutes the environment, inconsistent with the concept of green production.

[0004] Therefore, according to the above-mentioned related technologies, there is an urgent need to develop a concrete activator based on inorganic solid waste and a preparation method thereof. Summary of the Invention

[0005] In view of this, the purpose of the present invention is to propose a concrete activator based on inorganic solid waste and its preparation method, so as to provide an environmentally friendly, low-energy, high-value-added recycling process method for high-silicon inorganic solid waste, improve the recycling rate of high-silicon solid waste, and at the same time solve the problem of waste residue emissions in the wet production process, thereby preparing a concrete activator with excellent performance.

[0006] Based on the above objectives, the present invention provides a concrete activator based on inorganic solid waste and a preparation method thereof.

[0007] A concrete activator based on inorganic solid waste comprises the following raw materials in parts by weight: 160-240 parts of high-silicon solid waste base material, 74 parts of carbide slag, 106 parts of by-product sodium carbonate, 3-10 parts of modified complex enzyme microcapsules, 5 parts of polyether polyol, 2-8 parts of surfactant and 3-5 parts of organic acid.

[0008] The use of 160-240 parts of high-silicon solid waste base material, 74 parts of carbide slag and 106 parts of by-product sodium carbonate is on the one hand to accurately control the alkalinity (Na2O / SiO2 molar ratio 1.2-1.8) to ensure that the silicon and aluminum components in the solid waste are fully dissolved, while avoiding the strength reduction caused by excessive alkali. At the same time, in order to achieve a balance between cost and performance: the ratio of by-product sodium carbonate and carbide slag is optimized, and under the premise of ensuring alkalinity, the utilization of industrial by-products is maximized to reduce costs.

[0009] Preferably, the high-silicon solid waste base material is waste glass, tailings and fly ash in a mass ratio of 3:2:1.

[0010] The core function of the high-silicon solid waste base material is to provide active components such as silicon and aluminum as the main reaction matrix of the activator. Waste glass is rich in amorphous SiO2, which is easily dissolved under alkaline conditions to form SiO3 2- , participate in the construction of gel network; the tailings contain quartz, feldspar and other minerals, whose aluminum silicate structure is destroyed by alkali under high temperature and high pressure, releasing active SiO2 and Al2O3; the fly ash contains high silicon and high aluminum glass particles, Al2O3 and OH - The reaction produces AlO2 - , and cooperates with silicate to form zeolite-like gel. In addition, the introduction of high-silicon solid waste base material makes the consumption of solid waste per ton of activator 160-240kg, realizing "waste instead of material" and reducing raw material costs by more than 40%.

[0011] The carbide slag is used as an alkaline excitation source, and its main component is Ca(OH)2, which reacts with the by-product sodium carbonate to generate NaOH, providing high concentration OH - (Reaction formula: Ca(OH)2+Na2CO3=CaCO3↓+2Na + +2OH - ), promotes the dissolution of silicon-aluminum minerals in solid waste, and releases Ca 2+ It reacts with silicate and aluminate to form CSH (calcium silicate hydrate) and CASH (calcium aluminosilicate hydrate) gels, which enhance the strength of concrete.

[0012] The by-product sodium carbonate acts as an alkalinity regulator: it reacts with carbide slag to generate NaOH, maintains high alkalinity of the system (pH ≥ 12), and accelerates the dissolution of SiO2 and Al2O3 in solid waste (such as SiO2+2OH - =SiO3 2- +H2O), and utilize industrial by-product alkali to reduce the cost of alkaline activator, which is 30% lower than the cost of industrial caustic soda (NaOH).

[0013] Preferably, the preparation process of the modified complex enzyme microcapsules is as follows:

[0014] Step A1. Add the complex enzyme and chitosan in a mass ratio of 1:2.8 to water, adjust the pH to 8-10, and freeze-dry to a water content of ≤0.5% to obtain complex enzyme microcapsules;

[0015] Step A2. Add the composite enzyme microcapsules and tridecafluorooctyltriethoxysilane in a mass ratio of 1:4.7 to acetone, perform a modification treatment at 55° C., and evaporate the solvent to obtain the modified composite enzyme microcapsules.

[0016] Preferably, the complex enzyme in step A1 is obtained by mixing carbonic anhydrase and urease in a mass ratio of 50-69:32-50, the activity of the carbonic anhydrase is ≥2500 U / mg, and the activity of the urease is ≥2000 U / mg.

[0017] Preferably, the deacetylation degree of the chitosan in step A1 is ≥95%, and the molecular weight Mw of the chitosan is 30,000-40,000.

[0018] The modified composite enzyme microcapsule is used as an enzyme catalytic system, wherein carbonic anhydrase (50-68wt%, activity ≥2500U / mg): catalyzes the hydration reaction of CO2 to generate H2CO3, and dissociates CO3 2- , and Ca 2+ The reaction generates CaCO3 crystals, which fill the gel pores and enhance strength (compressive strength increases by 20-30%). Urease (32-50wt%, activity ≥2000U / mg) decomposes urea to produce NH3 and CO2. NH3 dissolves in water to form NH3·H2O, maintaining the alkalinity of the system and promoting carbonic anhydrase activity, creating a synergistic "base excitation-enzyme catalysis" effect. Furthermore, chitosan (degree of deacetylation ≥95%, Mw 30,000-40,000) encapsulates the enzyme to form a protective layer, preventing inactivation during the hydrothermal reaction (200-280°C). It also reacts with fluorinated silane to form Si-O-Si bonds, enhancing microcapsule stability. Tridecafluorooctyltriethoxysilane is used to modify the microcapsule surface, creating a hydrophobic environment to prevent enzyme inactivation through direct contact with water. It also promotes microcapsule dispersion in the slurry and improves catalytic efficiency.

[0019] The polyether polyol has a dispersing and solubilizing effect. The hydroxyl groups therein form hydrogen bonds with the silanol groups (-SiOH) on the surface of the modified composite enzyme microcapsules, promoting uniform dispersion of the microcapsules and avoiding agglomeration (dispersion increased by 40%). In addition, as a non-ionic surfactant, it can also reduce the surface tension of the slurry, improve workability, reduce water consumption (water reduction rate of 15-20%), and increase the density of concrete.

[0020] Preferably, the surfactant is calcium lignin sulfonate, which is adsorbed on the surface of cement particles to generate electrostatic repulsion, reduce particle agglomeration, lower the water-cement ratio, and improve concrete strength. In addition, it can also slow down the cement hydration rate, extend the construction operation time, and avoid premature setting.

[0021] Preferably, the organic acid is acetic acid, which acts as a pH buffer regulator to neutralize part of the strong base, maintain the system pH at 10-12, avoid enzyme inactivation caused by excessive alkalinity, promote chitosan dissolution, and optimize microcapsule preparation conditions. In addition, the organic acid also has a chelating effect and can react with Ca 2+ It forms soluble chelates, slows down the crystallization of CaCO3, ensures uniform growth of initial crystals, and improves the microstructure of concrete.

[0022] A method for preparing a concrete activator based on inorganic solid waste comprises the following steps:

[0023] Step S1. Crushing: Crushing the high-silicon inorganic solid waste to a diameter of 8-12 mm to obtain high-silicon inorganic solid waste particles. Crushing the solid waste to approximately 10 mm increases the specific surface area (by 2-3 times), accelerates the contact reaction between the alkaline activator and the solid waste, shortens the hydrothermal reaction time (from 8 hours in the traditional process to 4-6 hours), and avoids uneven batching caused by large solid waste particles, ensuring that the subsequent pulping fineness meets the standard (above 200 mesh);

[0024] Step S2: metering and batching high-silicon inorganic solid waste particles, carbide slag, and by-product sodium carbonate to obtain a mixture;

[0025] Step S3. Slurrying: Water is added to the mixture to control the fineness to above 200 mesh and maintain the concentration at 50%-60% to obtain a slurry. A fineness of above 200 mesh (pass rate ≥ 95%) makes the solid waste particle diameter less than 74 μm, increases the exposure of silicon and aluminum active sites, and improves the hydrothermal reaction rate (dissolution rate increases by 15-20%). A concentration of 50-60% ensures that the slurry has an appropriate viscosity (200-300 mPa·s), avoiding both excessive dilution that reduces reactor efficiency and excessive thickening that affects stirring uniformity.

[0026] Step S4. Complex enzyme microcapsule compounding: premixing polyether polyol and modified complex enzyme microcapsules to form a first mixture, and simultaneously mixing surfactant, organic acid and water to form a second mixture. The polyether polyol and microcapsules are premixed to form a "core-shell" structure, which prevents microcapsule aggregation through steric hindrance and increases the dispersion in the slurry to more than 90%. The mixture of surfactant and organic acid adjusts the polarity of the slurry, promotes uniform distribution of the polyether-microcapsule complex, and ensures that the enzyme catalysis covers the entire system.

[0027] Step S5. Hydrothermal reaction: The first mixture, the second mixture, and the slurry are added to the reactor, with the slurry volume controlled to 1 / 2-2 / 3 of the reactor volume. The reaction is carried out at 200-280°C for 4-6 hours. For solid waste with high silicon content (such as waste glass), the reaction temperature is kept low at 200°C to prevent excessive dissolution of SiO2, which may lead to a loose gel structure. For solid waste with low silicon content (such as tailings), the reaction temperature is kept high at 280°C to promote the decomposition of minerals such as feldspar. The slurry volume is controlled at 1 / 2-2 / 3 to ensure the formation of autogenous pressure (1-3MPa) in the reactor, accelerating the breakage of Si-O and Al-O bonds, generating low-polymerization silicate and aluminate, and improving the strength of the gelled product. The 4-6 hour reaction time ensures a silicon and aluminum dissolution rate of ≥85% while avoiding the increase in energy consumption caused by excessive reaction time (which is lower than the energy consumption of traditional dry processes).

[0028] Step S6. Post-processing: Post-process the reaction product to obtain a concrete activator.

[0029] Among them, the main reactions of carbide slag and by-product sodium carbonate are as follows:

[0030] Ca(OH)2+Na2CO3=CaCO3↓+2Na + +2OH - .

[0031] The high temperature and high pressure hydrothermal reaction of quartz tailings is as follows:

[0032] SiO2+2OH - =SiO3 2- +H2O.

[0033] The high temperature and high pressure hydrothermal reaction of feldspar tailings is as follows:

[0034] KAlSi3O8+6OH - =K + +AlO2 - +3SiO3 2- +3H2O;

[0035] NaAlSi3O8+6OH - =K + +AlO2 - +3SiO3 2- +3H2O;

[0036] CaAl2Si2O8+4OH - =Ca 2+ +2AlO2 - +2SiO3 2- +2H2O.

[0037] The high-temperature and high-pressure hydrothermal reactions of waste glass are as follows:

[0038] Na2SiO3=2Na + +SiO3 2- ;

[0039] CaSiO3=Ca 2+ +SiO3 2- .

[0040] The high temperature and high pressure hydrothermal reaction of fly ash is as follows:

[0041] Al2O3+2OH - =2AlO2 - +H2O;

[0042] SiO2+2OH - =SiO3 2- +H2O.

[0043] Preferably, the pulping in step S3 is any one of grinding pulping and mixing pulping.

[0044] Preferably, the post-treatment in step S6 is any one of evaporation concentration and product preparation, and the evaporation concentration is to a density of 1.4-1.6 g / cm 3 , suitable for high-strength concrete with low water-binder ratio; mix to density 1.2-1.3g / cm 3 It is suitable for lightweight concrete and can meet the needs of different projects. In addition, by adding retarders or early strength agents during the mixing process, the product can be adapted to winter construction or rapid demoulding scenarios to expand the scope of application.

[0045] The present invention uses a solid waste-alkali-enzyme ternary activation mechanism: high-silicon solid waste provides an aluminum source, carbide slag and by-product sodium carbonate provide an alkaline environment, and modified complex enzyme microcapsules catalyze CaCO3 crystallization. The three work together to increase the compressive strength of concrete to 35-40MPa in 3 days (traditional activators only have 15-20MPa), and 65-75MPa in 28 days (an increase of 85%).

[0046] Microcapsule-polyether dispersion system: Chitosan-fluorinated silicone ether modified microcapsules are evenly dispersed through polyether polyols, ensuring uniform distribution of enzyme catalytic sites. CaCO3 crystals penetrate the gelling network, increasing the flexural strength of concrete by 20-30% and achieving a softening coefficient ≥0.95 (excellent water resistance).

[0047] Green preparation process: Hydrothermal reaction replaces high-temperature sintering, reducing energy consumption by 60% and eliminating waste residue emissions; the utilization of by-product alkali and solid waste reduces carbon emissions per unit product by 55kgCO2 / t, achieving a triple breakthrough in "solid waste resource utilization - performance improvement - environmental protection and energy saving."

[0048] Beneficial effects of the present invention:

[0049] The present invention provides a concrete activator based on inorganic solid waste and a preparation method thereof. The present invention combines high-silicon solid waste with modified composite enzyme microcapsules for the first time to form a "solid waste base material-enzyme catalysis" composite activation system, and the raw material cost is reduced compared with the traditional process; and through the synergy of alkali activation and enzyme catalysis, the compressive strength of concrete is improved. The solid waste consumption per ton of the activator provided by the present invention reaches 160-240 kg, which is 30% higher than the traditional process, realizing "treating waste with waste", and the compressive strength and flexural strength of the concrete prepared by the activator of the present invention are improved, no waste residue is discharged during the production process, the energy consumption is significantly reduced compared with the dry process, and the carbon emission per unit product is reduced, breaking through the performance bottleneck of the existing activators, and providing a new technical path for solid waste-based building materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only for the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0051] Figure 1 It is the main process flow chart of the present invention. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to specific embodiments.

[0053] Example 1: A method for preparing a concrete activator based on inorganic solid waste, comprising the following steps:

[0054] S1. Waste glass, tailings and fly ash are mixed in a mass ratio of 3:2:1 to obtain a high-silicon solid waste base;

[0055] S2. Carbonic anhydrase and urease were mixed in a mass ratio of 50:32 to obtain a composite enzyme, wherein the activity of carbonic anhydrase was ≥2500 U / mg and the activity of urease was ≥2000 U / mg;

[0056] S3. The enzyme complex and chitosan were added to water in a mass ratio of 1:2.8, the pH was adjusted to 8-10, and freeze-dried to a water content of ≤0.5% to obtain enzyme complex microcapsules, wherein the degree of deacetylation of chitosan was ≥95%, and the molecular weight Mw of chitosan was 30,000-40,000;

[0057] S4. The composite enzyme microcapsules and tridecafluorooctyl triethoxysilane were added to acetone at a mass ratio of 1:4.7, and the modified microcapsules were prepared by evaporating the solvent at 55 ° C.

[0058] S5. Crushing: Crushing the high-silicon inorganic solid waste to a diameter of 8-12 mm to obtain high-silicon inorganic solid waste particles. Crushing the solid waste to about 10 mm increases the specific surface area, accelerates the contact reaction between the alkaline activator and the solid waste, shortens the hydrothermal reaction time, and avoids uneven batching caused by large solid waste particles, ensuring that the subsequent pulping fineness meets the standard (above 200 mesh);

[0059] S6 metering ingredients: 160 parts of high-silicon inorganic solid waste particles, 74 parts of carbide slag, 106 parts of by-product sodium carbonate were measured to obtain a mixture;

[0060] S7. Pulping: Add water to the mixture to control the fineness to above 200 mesh and maintain the concentration at 50%-60% to obtain a slurry. A fineness above 200 mesh (pass rate ≥ 95%) makes the solid waste particle diameter less than 74μm, increases the exposure of silicon and aluminum active sites, and improves the hydrothermal reaction rate (dissolution rate increases by 15-20%). A concentration of 50%-60% ensures that the slurry has an appropriate viscosity (200-300mPa·s), avoiding both excessive dilution that reduces reactor efficiency and excessive thickening that affects stirring uniformity. The slurrying method can be either grinding slurrying or mixing slurrying;

[0061] S8. Complex enzyme microcapsule compounding: 5 parts of polyether polyol and 3 parts of modified complex enzyme microcapsules are premixed to form a first mixture. Simultaneously, 2 parts of calcium lignin sulfonate, 3 parts of acetic acid, and water are mixed to form a second mixture. The polyether polyol and microcapsules are premixed to form a "core-shell" structure. This steric hindrance prevents microcapsule aggregation and increases the dispersion in the slurry to over 90%. The surfactant and organic acid mixture adjusts the slurry polarity, promotes uniform distribution of the polyether-microcapsule complex, and ensures that the enzyme catalysis covers the entire system.

[0062] S9. Hydrothermal reaction: Add the first mixture, the second mixture, and the slurry to the reactor, controlling the slurry volume to 1 / 2-2 / 3 of the reactor volume. React at 200°C for 4 hours. For solid waste with high silicon content (such as waste glass), use a low temperature of 200°C to avoid excessive dissolution of SiO2, which will lead to a loose gel structure. The slurry volume is controlled at 1 / 2-2 / 3 to ensure the formation of autogenous pressure (1-3MPa) in the reactor, accelerate the breakage of Si-O and Al-O bonds, generate low-polymerization silicate and aluminate, and enhance the strength of the gelled product. The 4-6h reaction time ensures a silicon and aluminum dissolution rate of ≥85% while avoiding increased energy consumption due to excessive reaction time (lower energy consumption compared to traditional dry process).

[0063] S10. Post-processing: Post-process the reaction product to obtain a concrete activator, wherein the post-processing is any one of evaporation concentration and product blending, and the evaporation concentration is to a density of 1.4-1.6g / cm 3, suitable for high-strength concrete with low water-binder ratio, mixed to a density of 1.2-1.3g / cm 3 It is suitable for lightweight concrete and can meet the needs of different projects. In addition, by adding retarders or early strength agents during the mixing process, the product can be adapted to winter construction or rapid demoulding scenarios to expand the scope of application.

[0064] Example 2: A method for preparing a concrete activator based on inorganic solid waste, comprising the following steps:

[0065] S1. Waste glass, tailings and fly ash are mixed in a mass ratio of 3:2:1 to obtain a high-silicon solid waste base;

[0066] S2. Carbonic anhydrase and urease were mixed in a mass ratio of 60:40 to obtain a composite enzyme, wherein the activity of carbonic anhydrase was ≥2500 U / mg and the activity of urease was ≥2000 U / mg;

[0067] S3. The enzyme complex and chitosan were added to water in a mass ratio of 1:2.8, the pH was adjusted to 8-10, and freeze-dried to a water content of ≤0.5% to obtain enzyme complex microcapsules, wherein the degree of deacetylation of chitosan was ≥95%, and the molecular weight Mw of chitosan was 30,000-40,000;

[0068] S4. The composite enzyme microcapsules and tridecafluorooctyl triethoxysilane were added to acetone at a mass ratio of 1:4.7, and the modified microcapsules were prepared by evaporating the solvent at 55 ° C.

[0069] S5. Crushing: Crushing the high-silicon inorganic solid waste to a diameter of 8-12 mm to obtain high-silicon inorganic solid waste particles. Crushing the solid waste to about 10 mm increases the specific surface area, accelerates the contact reaction between the alkaline activator and the solid waste, shortens the hydrothermal reaction time, and avoids uneven batching caused by large solid waste particles, ensuring that the subsequent pulping fineness meets the standard (above 200 mesh);

[0070] S6 metering ingredients: 200 parts of high-silicon inorganic solid waste particles, 74 parts of carbide slag, 106 parts of by-product sodium carbonate were measured to obtain a mixture;

[0071] S7. Pulping: Add water to the mixture to control the fineness to above 200 mesh and maintain the concentration at 50%-60% to obtain a slurry. A fineness above 200 mesh (pass rate ≥ 95%) makes the solid waste particle diameter less than 74μm, increases the exposure of silicon and aluminum active sites, and improves the hydrothermal reaction rate (dissolution rate increases by 15-20%). A concentration of 50%-60% ensures that the slurry has an appropriate viscosity (200-300mPa·s), avoiding both excessive dilution that reduces reactor efficiency and excessive thickening that affects stirring uniformity. The slurrying method can be either grinding slurrying or mixing slurrying;

[0072] S8. Enzyme-microcapsule complexing: 5 parts of polyether polyol and 6 parts of modified enzyme-complex microcapsules are premixed to form a first mixture. Simultaneously, 5 parts of calcium lignin sulfonate, 4 parts of acetic acid, and water are mixed to form a second mixture. The polyether polyol and microcapsules are premixed to form a "core-shell" structure. This steric hindrance prevents microcapsule aggregation and increases the dispersion in the slurry to over 90%. The surfactant and organic acid mixture adjusts the slurry polarity, promotes uniform distribution of the polyether-microcapsule complex, and ensures that the enzyme catalysis covers the entire system.

[0073] S9. Hydrothermal reaction: Add the first mixture, the second mixture, and the slurry to the reactor, controlling the slurry volume to 1 / 2-2 / 3 of the reactor volume, and react at 240°C for 5 hours. For solid waste with high silicon content (such as waste glass), the reaction temperature should be low at 200°C to avoid excessive dissolution of SiO2, which will lead to a loose gel structure. For solid waste with low silicon content (such as tailings), the reaction temperature should be high at 280°C to promote the decomposition of minerals such as feldspar. The slurry volume should be controlled at 1 / 2-2 / 3 to ensure the formation of autogenous pressure (1-3MPa) in the reactor, accelerate the breakage of Si-O and Al-O bonds, generate low-polymerization silicate and aluminate, and enhance the strength of the gelled product. The 4-6h reaction time ensures that the silicon and aluminum dissolution rate is ≥85%, while avoiding the increase in energy consumption caused by excessive reaction time (lower energy consumption compared to traditional dry process).

[0074] S10. Post-processing: Post-process the reaction product to obtain a concrete activator, wherein the post-processing is any one of evaporation concentration and product blending, and the evaporation concentration is to a density of 1.4-1.6g / cm 3 , suitable for high-strength concrete with low water-binder ratio, mixed to a density of 1.2-1.3g / cm 3 It is suitable for lightweight concrete and can meet the needs of different projects. In addition, by adding retarders or early strength agents during the mixing process, the product can be adapted to winter construction or rapid demoulding scenarios to expand the scope of application.

[0075] Example 3: A method for preparing a concrete activator based on inorganic solid waste, comprising the following steps:

[0076] S1. Waste glass, tailings and fly ash are mixed in a mass ratio of 3:2:1 to obtain a high-silicon solid waste base;

[0077] S2. Carbonic anhydrase and urease were mixed in a mass ratio of 69:50 to obtain a composite enzyme, wherein the activity of carbonic anhydrase was ≥2500 U / mg and the activity of urease was ≥2000 U / mg;

[0078] S3. The enzyme complex and chitosan were added to water in a mass ratio of 1:2.8, the pH was adjusted to 8-10, and freeze-dried to a water content of ≤0.5% to obtain enzyme complex microcapsules, wherein the degree of deacetylation of chitosan was ≥95%, and the molecular weight Mw of chitosan was 30,000-40,000;

[0079] S4. The composite enzyme microcapsules and tridecafluorooctyl triethoxysilane were added to acetone at a mass ratio of 1:4.7, and the modified microcapsules were prepared by evaporating the solvent at 55 ° C.

[0080] S5. Crushing: Crushing the high-silicon inorganic solid waste to a diameter of 8-12 mm to obtain high-silicon inorganic solid waste particles. Crushing the solid waste to about 10 mm increases the specific surface area, accelerates the contact reaction between the alkaline activator and the solid waste, shortens the hydrothermal reaction time, and avoids uneven batching caused by large solid waste particles, ensuring that the subsequent pulping fineness meets the standard (above 200 mesh);

[0081] S6 metering ingredients: 240 parts of high-silicon inorganic solid waste particles, 74 parts of carbide slag, 106 parts of by-product sodium carbonate were measured to obtain a mixture;

[0082] S7. Pulping: Add water to the mixture to control the fineness to above 200 mesh and maintain the concentration at 50%-60% to obtain a slurry. A fineness above 200 mesh (pass rate ≥ 95%) makes the solid waste particle diameter less than 74μm, increases the exposure of silicon and aluminum active sites, and improves the hydrothermal reaction rate (dissolution rate increases by 15-20%). A concentration of 50-60% ensures that the slurry has an appropriate viscosity (200-300mPa·s), avoiding both excessive dilution that reduces reactor efficiency and excessive thickening that affects stirring uniformity. The slurrying method can be either grinding slurrying or mixing slurrying;

[0083] S8. Enzyme-microcapsule complexing: 5 parts of polyether polyol and 10 parts of modified enzyme-complex microcapsules are premixed to form a first mixture. 8 parts of calcium lignin sulfonate, 5 parts of acetic acid, and water are simultaneously mixed to form a second mixture. The polyether polyol and microcapsules are premixed to form a "core-shell" structure. This steric hindrance prevents microcapsule aggregation and increases the dispersion in the slurry to over 90%. The surfactant and organic acid mixture adjusts the slurry polarity, promotes uniform distribution of the polyether-microcapsule complex, and ensures that the enzyme catalysis covers the entire system.

[0084] S9. Hydrothermal reaction: Add the first mixture, the second mixture, and the slurry to the reactor, controlling the slurry volume to 1 / 2-2 / 3 of the reactor volume. React at 280°C for 6 hours. For solid waste with low silicon content (such as tailings), heat it to 280°C to promote the decomposition of minerals such as feldspar. The slurry volume is controlled at 1 / 2-2 / 3 to ensure the formation of autogenous pressure (1-3MPa) in the reactor, accelerate the breakage of Si-O and Al-O bonds, generate low-polymerization silicate and aluminate, and enhance the strength of the gelled product. The 4-6 hour reaction time ensures a silicon and aluminum dissolution rate of ≥85% while avoiding the increase in energy consumption caused by excessive reaction time (lower energy consumption compared to traditional dry processes).

[0085] S10. Post-processing: Post-process the reaction product to obtain a concrete activator, wherein the post-processing is any one of evaporation concentration and product blending, and the evaporation concentration is to a density of 1.4-1.6g / cm 3 , suitable for high-strength concrete with low water-binder ratio, mixed to a density of 1.2-1.3g / cm 3 It is suitable for lightweight concrete and can meet the needs of different projects. In addition, by adding retarders or early strength agents during the mixing process, the product can be adapted to winter construction or rapid demoulding scenarios to expand the scope of application.

[0086] Comparative Example 1:

[0087] Compared with Example 1, in this comparative example, the modified composite enzyme microcapsules were not added during the preparation of the concrete activator. The modified composite enzyme microcapsules were removed, and the remaining raw materials and proportions were the same as in Example 1 (160 parts of high-silicon solid waste base material, 74 parts of carbide slag, 106 parts of by-product sodium carbonate, 5 parts of polyether polyol, 2 parts of calcium lignin sulfonate, and 3 parts of acetic acid). The microcapsule preparation and compounding steps were omitted, and the polyester polyol was directly mixed with the other components. The remaining steps were consistent with Example 1. This comparative example aims to verify the key role of the modified composite enzyme microcapsules in improving strength and durability.

[0088] Comparative Example 2:

[0089] Compared with Example 1, in this comparative example, no polyether polyol was added during the preparation of the concrete activator. The polyether polyol was removed, and the remaining raw materials and proportions were the same as in Example 2 (200 parts of high-silicon solid waste base material, 6 parts of modified complex enzyme microcapsules, 5 parts of calcium lignin sulfonate, and 4 parts of acetic acid). The premixing step of the polyether polyol and the modified complex enzyme microcapsules was omitted, and the modified complex enzyme microcapsules were directly added to the second mixture. The remaining steps were consistent with Example 2. This comparative example aims to verify the effect of polyether polyol on the dispersibility of the modified complex enzyme microcapsules and the fluidity of the slurry.

[0090] Comparative Example 3:

[0091] Compared with Example 3, this comparative example uses a single high-silicon solid waste base material, that is, only 240 parts of waste glass are used as the high-silicon solid waste base material, and tailings and fly ash are removed. The remaining raw materials and proportions are the same as those in Example 3 (10 parts of modified complex enzyme microcapsules, 5 parts of polyether polyols, 8 parts of calcium lignin sulfonate, and 5 parts of acetic acid). The remaining steps are consistent with Example 3, but the solid waste crushing and ingredients are only for waste glass. This comparative example is intended to verify the synergistic effect of waste glass, tailings, and fly ash compounded in a ratio of 3:2:1.

[0092] Comparative Example 4:

[0093] This comparative example uses a traditional wet-process water glass activator, and the raw materials are 200 kg of high-purity quartz sand and 80 kg of industrial caustic soda (no high-silicon solid waste base material and modified complex enzyme microcapsules are used). The reaction is pressurized at 120°C for 8 hours, and then filtered and concentrated. This comparative example is intended to compare the performance and cost differences between the present invention and the prior art.

[0094] Performance test: The concrete activators prepared in Examples 1-3 and Comparative Examples 1-4 were used to prepare concrete samples, and the following performance tests were performed on each concrete sample:

[0095] Compressive strength: Refer to GB / T50081-2019 "Standard for Test Methods of Physical and Mechanical Properties of Concrete" and test the 3-day and 28-day strength.

[0096] Flexural strength: Same as above, tested using the three-point bending method.

[0097] Saturated water absorption rate: refer to JG / T266-2011 "Foam Concrete", and calculate by weighing the sample after soaking in water for 48 hours.

[0098] Production cost: calculated based on the market price of raw materials and process energy consumption (yuan / ton of activator).

[0099] Energy consumption: Calculate the energy consumption per unit product (kWh / t) during the hydrothermal reaction stage.

[0100] The results are shown in Tables 1 and 2 below:

[0101] Table 1

[0102]

[0103] Table 2

[0104]

[0105] Data Analysis:

[0106] As can be seen from Table 1, the concrete prepared using the concrete activator prepared by the present invention has better performance, which may be due to:

[0107] 1. Effect of the modified composite enzyme microcapsules: Compared with Example 1, the 3-day compressive strength of Comparative Example 1 decreased by 20.6%, the 28-day compressive strength decreased by 24.6%, and the water absorption rate increased by 67.9%, proving that the modified composite enzyme microcapsules significantly improved the strength and water resistance by catalyzing the crystallization of CaCO3.

[0108] 2. Synergistic effect of polyether polyols: Compared with Example 2, the 3-day compressive strength of Comparative Example 2 decreased by 15.9%, the 28-day compressive strength decreased by 14.5%, and the saturated water absorption rate increased by 21.9%. It is shown that the surface polyether polyols optimized the gel network structure by improving the dispersibility of the modified composite enzyme microcapsules.

[0109] 3. Advantages of high-silicon solid waste base material: Comparative Example 3 only uses a single waste glass. As a result, the compressive strength of the sample in Comparative Example 3 decreased by 23.6% after 3 days and by 22.0% after 28 days compared with Example 3, indicating that when waste glass, tailings, and fly ash are compounded in a ratio of 3:2:1, the synergistic dissolution effect of the silicon and aluminum active components is better.

[0110] 4. Compared with the prior art: Comparative Example 4 adopts the traditional wet method. The 3-day compressive strength of Comparative Example 4 is only 44.1% of that of Example 1, and the 28-day compressive strength is only 46.8% of that of Example 1. The production cost increases by 77.1% and the energy consumption increases by 150%, highlighting the comprehensive advantages of the present invention in terms of performance, cost and environmental protection.

[0111] 5. Process parameter optimization: In Examples 1-3, as the high-silicon solid waste base material increases from 160 parts to 240 parts, the strength gradually increases, but the production cost also increases accordingly. An economic ratio can be selected according to project requirements, such as 200 parts of high-silicon solid waste base material in Example 2.

[0112] 6. By comparing the comparative examples with the embodiments, the present invention achieves high performance, low cost and greenness of concrete activators through the "solid waste-alkali-enzyme" ternary system and process innovation, and has significant technological progress and practical application value.

[0113] The use of 160-240 parts of high-silicon solid waste base material, 74 parts of carbide slag and 106 parts of by-product sodium carbonate is on the one hand to accurately control the alkalinity (Na2O / SiO2 molar ratio 1.2-1.8) to ensure that the silicon and aluminum components in the solid waste are fully dissolved, while avoiding the strength reduction caused by excessive alkali. At the same time, in order to achieve a balance between cost and performance: the ratio of by-product sodium carbonate and carbide slag is optimized, and under the premise of ensuring alkalinity, the utilization of industrial by-products is maximized to reduce costs.

[0114] The core function of high-silicon solid waste base material is to provide active components such as silicon and aluminum as the main reaction matrix of the activator. Waste glass is rich in amorphous SiO2, which is easily dissolved under alkaline conditions to form SiO3 2- , participate in the construction of gel network; the tailings contain quartz, feldspar and other minerals, whose aluminum silicate structure is destroyed by alkali under high temperature and high pressure, releasing active SiO2 and Al2O3; the fly ash contains high silicon and high aluminum glass particles, Al2O3 and OH - The reaction produces AlO2 - , and cooperates with silicate to form zeolite-like gel. In addition, the introduction of high-silicon solid waste base material makes the consumption of solid waste per ton of activator 160-240kg, realizing "waste instead of material" and reducing raw material costs by more than 40%.

[0115] As an alkaline excitation source, carbide slag, whose main component is Ca(OH)2, reacts with by-product sodium carbonate to generate NaOH, providing high concentration OH - (Reaction formula: Ca(OH)2+Na2CO3=CaCO3↓+2Na + +2OH - ), promotes the dissolution of silicon-aluminum minerals in solid waste, and releases Ca 2+ It reacts with silicate and aluminate to form CSH (calcium silicate hydrate) and CASH (calcium aluminosilicate hydrate) gels, which enhance the strength of concrete.

[0116] By-product sodium carbonate is used as alkalinity regulator: it reacts with carbide slag to generate NaOH, maintains high alkalinity of the system (pH ≥ 12), and accelerates the dissolution of SiO2 and Al2O3 in solid waste (such as SiO2+2OH - =SiO3 2- +H2O), and utilize industrial by-product alkali to reduce the cost of alkaline activator, which is 30% lower than the cost of industrial caustic soda (NaOH).

[0117] Modified composite enzyme microcapsules are used as enzyme catalytic system, in which carbonic anhydrase (50-68wt%, activity ≥2500U / mg): catalyzes CO2 hydration reaction to generate H2CO3, and dissociates CO3 2- , and Ca 2+ The reaction generates CaCO3 crystals, which fill the gel pores and enhance strength (compressive strength increases by 20-30%). Urease (32-50wt%, activity ≥2000U / mg) decomposes urea to produce NH3 and CO2. NH3 dissolves in water to form NH3·H2O, maintaining the alkalinity of the system and promoting carbonic anhydrase activity, creating a synergistic "base excitation-enzyme catalysis" effect. Furthermore, chitosan (degree of deacetylation ≥95%, Mw 30,000-40,000) encapsulates the enzyme to form a protective layer, preventing inactivation during the hydrothermal reaction (200-280°C). It also reacts with fluorinated silane to form Si-O-Si bonds, enhancing microcapsule stability. Tridecafluorooctyltriethoxysilane is used to modify the microcapsule surface, creating a hydrophobic environment to prevent enzyme inactivation through direct contact with water. It also promotes microcapsule dispersion in the slurry and improves catalytic efficiency.

[0118] Polyether polyol has the effect of dispersing and solubilizing. The hydroxyl groups in it form hydrogen bonds with the silanol groups (-SiOH) on the surface of the modified composite enzyme microcapsules, promoting the uniform dispersion of the microcapsules and avoiding agglomeration (dispersion increased by 40%). Moreover, as a non-ionic surfactant, it can also reduce the surface tension of the slurry, improve workability, reduce water consumption (water reduction rate 15-20%), and increase the density of concrete.

[0119] The surfactant is calcium lignin sulfonate, which will adsorb on the surface of cement particles, generate electrostatic repulsion, reduce particle agglomeration, lower the water-cement ratio, and improve concrete strength. In addition, it can also slow down the cement hydration rate, extend the construction operation time, and avoid premature setting.

[0120] The organic acid is acetic acid, which acts as a pH buffer regulator to neutralize some strong bases and maintain the system pH at 10-12, avoiding enzyme inactivation caused by excessive alkalinity, while promoting the dissolution of chitosan and optimizing the preparation conditions of microcapsules. In addition, the organic acid also has a chelating effect and can react with Ca 2+ It forms soluble chelates, slows down the crystallization of CaCO3, ensures uniform growth of initial crystals, and improves the microstructure of concrete.

[0121] Crushing solid waste to about 10mm increases the specific surface area (by 2-3 times), accelerates the contact reaction between alkaline activator and solid waste, shortens the hydrothermal reaction time (from 8 hours in traditional process to 4-6 hours), and avoids uneven batching caused by large particles of solid waste, ensuring that the subsequent pulping fineness meets the standard (above 200 mesh);

[0122] The polyether polyol and microcapsules are premixed to form a "core-shell" structure. This prevents microcapsule aggregation through steric hindrance, increasing the dispersion in the slurry to over 90%. The surfactant and organic acid mixture adjusts the slurry polarity, promoting uniform distribution of the polyether-microcapsule complex and ensuring that the enzyme catalysis covers the entire system.

[0123] The present invention uses a solid waste-alkali-enzyme ternary activation mechanism: high-silicon solid waste provides an aluminum source, carbide slag and by-product sodium carbonate provide an alkaline environment, and modified complex enzyme microcapsules catalyze CaCO3 crystallization. The three work together to increase the compressive strength of concrete to 35-40MPa in 3 days (traditional activators only have 15-20MPa), and 65-75MPa in 28 days (an increase of 85%).

[0124] The present invention adopts a microcapsule-polyether dispersion system: chitosan-fluorinated silicone ether modified microcapsules are uniformly dispersed through polyether polyols to ensure uniform distribution of enzyme catalytic sites. CaCO3 crystals penetrate the gelling network, thereby increasing the flexural strength of concrete by 20-30% and achieving a softening coefficient of ≥0.95 (excellent water resistance).

[0125] The present invention adopts a green preparation process: hydrothermal reaction replaces high-temperature sintering, reducing energy consumption by 60% and eliminating waste residue emissions; the utilization of by-product alkali and solid waste reduces carbon emissions per unit product by 55kgCO2 / t, achieving a triple breakthrough in "solid waste resource utilization - performance improvement - environmental protection and energy saving."

[0126] Those skilled in the art should understand that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention is limited to these examples. Within the scope of the present invention, the technical features in the above embodiments or different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the different aspects of the present invention as described above, which are not provided in detail for the sake of simplicity.

[0127] The present invention is intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A concrete activator based on inorganic solid waste, characterized in that: The method comprises the following raw materials in parts by weight: 160-240 parts of high-silicon solid waste base material, 74 parts of carbide slag, 106 parts of by-product sodium carbonate, 3-10 parts of modified complex enzyme microcapsules, 5 parts of polyether polyol, 2-8 parts of surfactant and 3-5 parts of organic acid; The high-silicon solid waste base material is obtained by mixing waste glass, tailings and fly ash in a mass ratio of 3:2:1; The preparation process of the modified composite enzyme microcapsule is as follows: Step A1. Add the complex enzyme and chitosan in a mass ratio of 1:2.8 to water, adjust the pH to 8-10, and freeze-dry to a water content of ≤0.5% to obtain complex enzyme microcapsules; Step A2. The composite enzyme microcapsules and tridecafluorooctyl triethoxysilane were added to acetone at a mass ratio of 1:4.7, and the mixture was modified at 55°C. After the solvent was evaporated, the modified composite enzyme microcapsules were obtained. The complex enzyme in step A1 is obtained by mixing carbonic anhydrase and urease in a mass ratio of 50-69:32-50, the activity of the carbonic anhydrase is ≥2500 U / mg, and the activity of the urease is ≥2000 U / mg.

2. The inorganic solid waste-based concrete activator according to claim 1, characterized in that: The deacetylation degree of the chitosan in step A1 is ≥95%, and the molecular weight Mw of the chitosan is 30,000-40,000.

3. The concrete activator based on inorganic solid waste according to claim 1, characterized in that: The surfactant is calcium lignin sulfonate, and the organic acid is acetic acid.

4. A method for preparing a concrete activator based on inorganic solid waste according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step S1. Crushing: Crushing the high-silicon solid waste base material to a diameter of 8-12 mm to obtain high-silicon inorganic solid waste particles; Step S2: metering and batching high-silicon inorganic solid waste particles, carbide slag, and by-product sodium carbonate to obtain a mixture; Step S3. Pulping: adding water to the mixture to control the fineness to be above 200 mesh and the concentration to be maintained at 50%-60% to obtain a slurry; Step S4. Compounding the enzyme microcapsules: premixing the polyether polyol and the modified enzyme microcapsules to form a first mixture, and simultaneously mixing the surfactant, the organic acid and water to form a second mixture; Step S5. Hydrothermal reaction: Add the first mixture, the second mixture and the slurry to the reactor, control the slurry volume to 1 / 2-2 / 3 of the reactor volume, and react at 200-280° C. for 4-6 hours; Step S6. Post-processing: Post-process the reaction product to obtain a concrete activator.

5. The method for preparing a concrete activator based on inorganic solid waste according to claim 4, characterized in that: The pulping in step S3 is any one of grinding pulping and mixing pulping.

6. The method for preparing a concrete activator based on inorganic solid waste according to claim 4, characterized in that: The post-processing in step S6 is any one of evaporation concentration and product preparation.

Images