A single-component alkali-activated engineering slag geopolymer, and a preparation method and application thereof

Abstract

This invention provides a single-component alkali-activated geopolymer from engineering waste soil, its preparation method, and its application, relating to the field of geopolymer technology. By mass percentage, the raw materials for preparing the single-component alkali-activated geopolymer from engineering waste soil provided by this invention include 100 parts of solid waste; 0-6 parts of alkali metal salt flux; 3-6 parts of solid alkali activator (calculated as sodium oxide); and 30-35 parts of water. By mass percentage, the solid waste includes 50-70% engineering waste soil and 30-50% slag. The engineering waste soil is calcined before use. When the calcination temperature is ≤800℃, the amount of alkali metal salt flux is not zero and it is mixed with the engineering waste soil before calcination. This invention calcines the engineering waste soil and alkali metal salt flux, incorporates slag, and reacts with the solid alkali activator to generate a gel material. By utilizing alkali activator technology and controlling the proportions of each raw material, the single-component alkali-activated geopolymer from engineering waste soil exhibits excellent compressive strength.

Description

Technical Field

[0001] This invention relates to the field of building material resource utilization technology, specifically to a single-component alkali-activated engineering slag soil polymer, its preparation method, and its application. Background Technology

[0002] The amount of abandoned construction waste is enormous, mainly originating from building demolition, construction, mining, and industrial production. Currently, the comprehensive utilization rate of abandoned construction waste is less than 10%, with most of it being directly landfilled or stockpiled.

[0003] Geopolymers are a novel type of inorganic polymer material produced from aluminosilicate materials through an alkaline-activated reaction. Their main raw materials are typically industrial byproducts rich in silicon and aluminum, such as fly ash, slag, and metakaolin. These react with alkaline activators (such as sodium hydroxide or sodium silicate) to form a cementitious material with a three-dimensional network structure. The production process of geopolymers is energy-efficient and produces low carbon emissions. Their compressive strength, tensile strength, and durability are generally superior to ordinary concrete, especially in high-temperature environments, making them highly promising for applications in construction, environmental protection, and high-temperature materials.

[0004] Currently, the main technology for utilizing engineering waste soil involves calcining the waste soil and then mixing it with a liquid alkali activator and other additives to obtain a geopolymer based on the engineering waste soil. For example, existing technology discloses a method for preparing a geopolymer road base material, including the following steps: mixing calcined engineering waste soil, uncalcined engineering waste soil, and an alkali activator at a mass ratio of 1:(0-4):(0.45-3.05), and carrying out a polymerization reaction to obtain a geopolymer road base material; the alkali activator includes water, sodium hydroxide, and water glass, and the 28-day compressive strength does not exceed 48.58 MPa. However, the compressive strength of the engineering waste soil-based polymer prepared by the above method is not high enough. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide a single-component alkali-activated engineering waste soil polymer, its preparation method, and its application. The single-component alkali-activated engineering waste soil polymer provided by this invention has high compressive strength.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] This invention provides a single-component alkali-activated engineering waste soil polymer, which, by mass parts, comprises: 100 parts solid waste; 0-6 parts alkali metal salt flux; 3-6 parts solid alkali activator (calculated as sodium oxide); and 30-35 parts water.

[0008] The solid waste comprises 50-70% engineering waste and 30-50% slag by mass percentage;

[0009] The engineering waste soil is calcined before use. When the calcination temperature is ≤800℃, the amount of alkali metal salt flux is not 0 and it is mixed with the engineering waste soil before calcination.

[0010] Preferably, the alkali metal salt flux includes one or more of alkali metal sulfates, alkaline earth metal sulfates, alkali metal carbonates, and alkaline earth metal carbonates.

[0011] Preferably, the solid alkali activator includes Na2SiO3 and / or calcined products, wherein the calcined products are calcined products of Na2CO3 and SiO2.

[0012] Preferably, the particle size of the engineering waste soil is ≥80 mesh.

[0013] Preferably, the particle size of the slag is 50–1000 nm.

[0014] This invention also provides a method for preparing the single-component alkali-activated engineering slag soil polymer described in the above technical solution, comprising the following steps:

[0015] The raw material to be calcined is calcined to obtain calcined material; when the calcination temperature is ≤800℃, the raw material to be calcined is a mixture of engineering slag and alkali metal salt flux; when the calcination temperature is >800℃, the raw material to be calcined is engineering slag, or a mixture of engineering slag and alkali metal salt flux.

[0016] The calcined material, slag, solid alkali activator and water are mixed to obtain geopolymer slurry;

[0017] After molding and curing the geopolymer slurry, a single-component alkali-activated engineering slag soil polymer is obtained.

[0018] Preferably, the calcination temperature is 550–950°C, and the holding time is 100–150 min.

[0019] Preferably, the mixing includes: first mixing the calcined material, slag, and solid alkali activator to obtain a dry material; second mixing the dry material with water; the rotation speed of the first mixing is 30-60 r / min and the time is 1-2 min; the rotation speed of the second mixing is 100-150 r / min and the time is 1-3 min.

[0020] Preferably, the molding temperature is 23–27°C, the relative humidity is 92–98%, and the time is 23–25 hours; the molding includes static molding.

[0021] The curing temperature is 23–27℃, the relative humidity is 92–98%, and the time is 1–28 days.

[0022] The present invention also provides the application of the single-component alkali-activated engineering slag soil polymer described in the above technical solution or the single-component alkali-activated engineering slag soil polymer prepared by the preparation method described in the above technical solution as a building material.

[0023] This invention involves calcining construction waste soil, which improves its physicochemical properties. It transforms the kaolin in the construction waste soil into more active metakaolin, altering the soil's structure and increasing its strength, hardness, and durability, making it more reusable. This, in turn, enhances the strength of the single-component alkali-activated polymer from the construction waste soil. Furthermore, calcination removes organic impurities and harmful substances (such as heavy metals) from the construction waste soil, reducing environmental hazards.

[0024] This invention involves calcining engineering waste soil and alkali metal salt flux together, then adding slag and reacting it with a solid alkali activator to generate a gel material. This invention utilizes alkali activator technology and controls the proportion of each raw material to obtain a single-component alkali-activated engineering waste soil polymer with excellent compressive strength, which has good market application prospects as a building material.

[0025] The alkali activator used in this invention is a solid, and at a low dosage, the single-component alkali-activated polymer from construction waste exhibits excellent compressive strength. Furthermore, compared to traditional water glass as an alkali activator, this invention uses a solid alkali activator, which is easier to store, transport, and operate, and can more efficiently solve the problem of utilizing waste construction waste.

[0026] Engineering waste soil exhibits certain activity under the action of solid alkali activators, and can act as a filler and alkali-activated gel material after the addition of solid alkali activators and slag. Compared with other mineral admixtures, slag, as a by-product of steel production, has a chemical composition more similar to that of ordinary cement. Slag contains finer and higher amounts of glassy particles, enhancing the reactivity of the mixture and accelerating the polymerization process. This effectively improves the mechanical properties of single-component alkali-activated engineering waste soil geopolymers and reduces the setting time of the geopolymer. This invention utilizes solid alkali activators to synergistically activate slag and engineering waste soil, achieving efficient geopolymer preparation. Specifically, under alkali activation conditions, slag rapidly releases silica-alumina monomers and calcium ions, promoting the formation of hydrated calcium aluminosilicate gel, providing strength support for the formation of the geopolymer's three-dimensional network structure. Simultaneously, engineering waste soil releases some active silica-alumina monomers under alkali activation, and the calcium ions dissolved from the slag further activate the kaolin component in the engineering waste soil, promoting the formation of hydrated sodium aluminosilicate gel. Although single-component alkali-activated geopolymers with excessive slag content have poor volume stability and are prone to microcracks, the slow reaction of engineering slag particles in the early stages can effectively fill pores, alleviate the volume mismatch problem caused by the rapid reaction of slag, and thus enhance the compressive strength of the geopolymer.

[0027] Moreover, this invention uses engineering waste and slag as the main raw materials, which not only consumes a large amount of different types of solid waste, but also saves a large amount of natural resources, thus achieving low-carbon emission reduction.

[0028] As shown in the test results of the examples, the 28-day compressive strength of the single-component alkali-activated engineering slag soil polymer provided by the present invention reaches a maximum of 80.7 MPa, which is high.

[0029] This invention also provides a method for preparing the single-component alkali-activated engineering waste soil polymer described in the above-mentioned technical solution. This invention involves calcining engineering waste soil and an alkali metal salt flux together, then incorporating slag and reacting it with a solid alkali activator to generate a gel material. By utilizing alkali activator technology and controlling the proportions of each raw material, a single-component alkali-activated engineering waste soil polymer with excellent compressive strength is prepared. Furthermore, the preparation method provided by this invention is simple in process, easy to operate, energy-saving, environmentally friendly, and suitable for industrial production.

[0030] The calcination of engineering waste soil and alkali metal flux together produces Na₂SiO₃ and NaAlO₂. Na₂SiO₃ provides active silicon, which directly acts as an activator to promote gel formation; NaAlO₂ provides active aluminum to enhance structural strength; and Na₂O or Na₂O is produced from the partial decomposition of the metal flux. + It can increase the pH value of the system, promote the dissolution of silica-alumina minerals in engineering waste, and accelerate the polymerization reaction. Attached Figure Description

[0031] Figure 1 The images show the dried construction waste (left) and the ground and sieved construction waste (right).

[0032] Figure 2 This is a photograph of the slag from the calcination process in Example 1;

[0033] Figure 3 The image shows the X-ray diffraction (XRD) pattern of the engineering waste soil in Example 1.

[0034] Figure 4 The images shown are scanning electron microscope (SEM) images of the construction waste soil in Example 1, where the left image is magnified at 3000x and the right image is magnified at 30000x.

[0035] Figure 5 This is a flowchart illustrating the preparation process of the single-component alkali-activated engineering slag soil polymer in this invention.

[0036] Figure 6 This is a photograph of the calcined material obtained by calcining the engineering waste soil and alkali metal flux in Example 3.

[0037] Figure 7 The images shown are SEM images of the slag in Example 1, where the left image is magnified 500 times and the right image is magnified 1000 times.

[0038] Figure 8 A photograph of the single-component alkali-activated engineering slag soil polymer prepared for Comparative Example 8 during the test of compressive strength.

[0039] Figure 9 The electron spectra of C1S, O1S, Si2P and Al2P of the single-component alkali-activated engineering slag soil polymers (3d age) prepared in Examples 2-4 are shown.

[0040] Figure 10 The single-component alkali-activated engineering slag soil polymers (28 days old) of Examples 1, 3, and 14 29 SiNMR and 27 AlNMR spectrum;

[0041] Figure 11 TIMA plot of the single-component alkali-activated engineering slag soil polymer (28 days old) prepared in Example 1;

[0042] Figure 12 TIMA plot of the single-component alkali-activated engineering waste soil polymer (28-day age) prepared in Example 3;

[0043] Figure 13TIMA plot of the single-component alkali-activated engineering slag soil polymer (28 days old) prepared in Example 28. Detailed Implementation

[0044] This invention provides a single-component alkali-activated engineering waste soil polymer, which, by mass parts, comprises: 100 parts solid waste; 0-6 parts alkali metal salt flux; 3-6 parts solid alkali activator (calculated as sodium oxide); and 30-35 parts water.

[0045] The solid waste comprises 50-70% engineering waste and 30-50% slag by mass percentage;

[0046] The engineering waste soil is calcined before use. When the calcination temperature is ≤800℃, the amount of alkali metal salt flux is not 0 and it is mixed with the engineering waste soil before calcination.

[0047] Unless otherwise specified, the materials and equipment used in this invention are all commercially available products in the field.

[0048] The raw materials for preparing the single-component alkali-activated engineering waste soil polymer provided by the present invention include 100 parts by weight of solid waste. In the present invention, the solid waste includes engineering waste soil and slag.

[0049] In this invention, the solid waste comprises 50-70% (by mass percentage) of engineering waste soil, specifically 50%, 52%, 55%, 58%, 60%, 62%, 65%, 68%, or 70% in certain embodiments. Preferably, the engineering waste soil is obtained by sequentially drying, crushing, and sieving engineering waste soil cake. The drying temperature is preferably 60-90°C, specifically 60°C, 70°C, 80°C, or 90°C in certain embodiments. The drying time is not specifically limited; drying to constant weight is sufficient. Sieving is preferably performed using an 80-mesh standard sieve, with the undersize portion used. The particle size of the engineering waste soil is preferably ≥80 mesh. The composition of the engineering waste soil is not specifically limited; any engineering waste soil well-known to those skilled in the art can be used. In this invention, the engineering waste soil is calcined before use. When the calcination temperature is ≤800℃, the amount of alkali metal salt flux is not zero and it is mixed with the engineering waste soil before calcination. When the calcination temperature is >800℃, the amount of alkali metal salt flux can be zero or not zero. The engineering waste soil exhibits certain activity under the action of a solid alkali activator, and can act as a filler and alkali-activated gel material after the addition of the solid alkali activator and slag, further improving the activity of the engineering waste soil. The main purpose of calcining the engineering waste soil is to improve its physicochemical properties through high-temperature treatment, converting a large amount of kaolin into more active metakaolin, making it more reusable. Calcination can remove organic impurities and harmful substances (such as heavy metals) from the engineering waste soil, reducing environmental hazards; simultaneously, high-temperature treatment can change the structure of the engineering waste soil, improving its strength, hardness, and durability.

[0050] In this invention, some of the reaction equations that occur when the engineering slag and alkali metal flux are calcined together are as follows:

[0051] At high temperatures (≤1100℃), only a small portion of Na2SO4 decomposes, producing Na2O and SO3: Na2SO4 → Na2O + SO3↑. The generated Na2O mainly reacts with the abundant SiO2 and AlO3 in the construction waste soil to form sodium silicate or sodium aluminate: Na2O + SiO2 → Na2SiO3, Na2O + Al2O3 → 2NaAlO2. The main reactions can be summarized as: Construction waste soil (SiO2 / Al2O3) + Na2SO4 → Na2SiO3 + NaAlO2 + SO3↑. Na2SO4 also reacts with small amounts of components in the construction waste soil (such as Fe2O3 and K2O) (minor reactions): Na2SO4 + Fe2O3 → 2NaFeO2 + SO3↑, K2O + SO3 → K2SO4, K2O + SiO2 → K2SiO3.

[0052] At high temperatures (≤1000℃), only a small portion of Na2CO3 decomposes, producing Na2O and CO2: Na2CO3→Na2O+CO2↑; Na2CO3 or Na2O mainly reacts with SiO2 and AlO3, which are abundant in engineering waste soil, to produce sodium silicate or sodium aluminate: Na2CO3+SiO2→Na2SiO3+CO2↑, Na2O+SiO2→Na2SiO3, Na2CO3+Al2O3→2NaAlO2+CO2↑, Na2O+Al2O3→2NaAlO2; The main reactions can be summarized as: Engineering waste soil (SiO2 / Al2O3)+Na2CO3→Na2SiO3+NaAlO2+CO2↑. Na2CO3 can also react with small amounts of components in the slag (such as Fe2O3 and K2O) (minor reactions): Na2SO4 + Fe2O3 → 2NaFeO2 + CO2↑, K2O + CO2 → K2CO3, K2O + SiO2 → K2SiO3.

[0053] The Na₂SiO₃ produced by calcination can provide active silicon, which can be used directly as an activator to promote gel formation; NaAlO₂ can provide active aluminum to enhance structural strength; Na₂O or Na produced by the partial decomposition of metal fluxes + It can increase the pH value of the system, promote the dissolution of silica-alumina minerals in engineering waste, and accelerate the polymerization reaction.

[0054] In this invention, the solid waste comprises 30-50% slag by mass percentage, and in specific embodiments, this can be 30%, 35%, 40%, 45%, or 50%. In this invention, the particle size of the slag is preferably 50-1000 nm, and in specific embodiments, it can be 50 nm, 100 nm, 200 nm, 500 nm, 800 nm, or 1000 nm. In this invention, the slag preferably comprises blast furnace slag, and the main chemical components of the slag preferably include: 38.40-40.84 wt% CaO, 29.69-31.61 wt% SiO2, and 15.91-17.86 wt% Al2O3; the strength grade of the slag is preferably S95; and the density of the slag is preferably 2.2-2.8 g / cm³. 3 In a specific implementation, it can be 2.2 g / cm³. 3 2.3g / cm 3 2.4g / cm 3 2.5g / cm 3 2.6g / cm 3 2.7g / cm 3 Or 2.8g / cm 3As a byproduct of steel production, blast furnace slag has a chemical composition more similar to that of ordinary cement. The glassy particles in blast furnace slag are finer and present in higher concentrations, enhancing the reactivity of the mixture and accelerating the polymerization process. This effectively improves the mechanical properties of single-component alkali-activated engineering slag geopolymers and reduces the setting time of the geopolymer. Furthermore, blast furnace slag can partially replace cement, reducing carbon emissions and resource consumption while improving durability. Blast furnace slag can be used to refine pores and improve the long-term strength of concrete, its resistance to sulfate and alkaline silica reactivity, and reduce water demand, permeability, and heat generation during hydration.

[0055] Based on the mass fraction of the solid waste, the raw materials for preparing the single-component alkali-activated engineering waste soil polymer provided by the present invention include 0 to 6 parts of alkali metal salt flux, which in specific embodiments can be 0 parts, 0.5 parts, 1 part, 1.5 parts, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 5.5 parts, or 6 parts. In the present invention, the alkali metal salt flux preferably includes one or more of alkali metal sulfates, alkaline earth metal sulfates, alkali metal carbonates, and alkaline earth metal carbonates; alkali metal sulfates and / or alkali metal carbonates; the alkali metal sulfates preferably include sodium sulfate and / or potassium sulfate; the alkaline earth metal sulfates preferably include magnesium sulfate and calcium sulfate; the alkali metal carbonates preferably include sodium carbonate and / or potassium carbonate; and the alkaline earth metal carbonates preferably include magnesium carbonate and calcium carbonate.

[0056] Based on the mass fraction of the solid waste, the raw materials for preparing the single-component alkali-activated engineering waste soil polymer provided by the present invention include 3 to 6 parts of solid alkali activator (based on the amount of sodium oxide), which in specific embodiments can be 3 parts, 3.5 parts, 4 parts, 4.5 parts, 5 parts, 6.5 parts, or 6 parts. In the present invention, the solid alkali activator preferably includes Na2SiO3 and / or calcined products, wherein the calcined products are calcined products of Na2CO3 and SiO2. In an alkaline environment, the abundant CaO in the slag dissolves and provides calcium ions, which is key to the formation of CSH gel. The slag also provides highly active SiO2 and Al2O3. After the layered structure of the slag soil is destroyed, active SiO2 and Al2O3 are released, which replenish SiO2 and Al2O3 and increase the total amount of the gel system. At the same time, CASH gel is generated, which enhances the compactness. Fine particles (clay, silt, etc.) in the slag soil fill the voids between the slag particles, improving the compactness. The CSH gel generated by alkali activation encapsulates the slag and slag soil particles, forming a three-dimensional network structure, which improves the overall strength of the material.

[0057] In this invention, the preferred method for preparing the calcined product includes the following steps: mixing Na2CO3 and SiO2 and then calcining to obtain the calcined product. In this invention, the molar ratio of Na2CO3 to SiO2 is preferably 1:1 to 2.5, and in specific embodiments it can be 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2, 1:2.2, or 1:2.5. In this invention, the calcination temperature is preferably 750–980°C, and in specific embodiments, it can be 750°C, 800°C, 850°C, 900°C, 950°C, or 980°C; the holding time for calcination is preferably 100–150 min, and in specific embodiments, it can be 100 min, 110 min, 120 min, 130 min, 140 min, or 150 min; the heating rate from room temperature to the calcination temperature is preferably 5–10°C / min, and in specific embodiments, it can be 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, or 10°C / min. After calcining the mixture of Na₂CO₃ and SiO₂, this invention preferably further includes: cooling the calcined system to room temperature to obtain the calcined product. This invention does not have a particular limitation on the cooling method; any cooling method well known to those skilled in the art can be used.

[0058] In this invention, the calcined product is preferably sodium silicate, or a mixture of sodium silicate and silicon dioxide. During the calcination process of Na2CO3 and SiO2, Na2CO3 first decomposes to generate sodium oxide (Na2O) and carbon dioxide (CO2), and then sodium oxide reacts with silicon dioxide in a solid-state reaction to generate sodium silicate (Na2SiO3). The chemical reaction equation for this process is: SiO2 + Na2CO3 3→ Na2SiO3 + CO2↑.

[0059] Liquid water glass is prone to gelation or precipitation during storage, especially at low temperatures or during long-term storage, which affects its performance and increases the difficulty of storage and transportation. Furthermore, water glass readily reacts with carbon dioxide in the air during use to form sodium carbonate, causing white crystals to appear on the surface, a phenomenon known as "alkali blooming." This not only affects the appearance but may also reduce the performance of geopolymers. This invention uses a solid alkali activator, which is easy to store and transport, and the operation process is simple, enabling a more efficient solution to the problem of utilizing waste construction waste.

[0060] In this invention, the variation in SiO2 and Na2O content in the solid alkali activator significantly affects the alkali activation effect of the single-component alkali-activated engineering slag soil polymer. Silicate ions and aluminosilicate ions generated from the activated engineering slag soil adsorb onto the surface of slag particles, filling the crystal ends, and undergo condensation reactions in an alkaline environment to form a blocky, dense structure, thereby improving the strength and durability of the single-component alkali-activated engineering slag soil polymer. The solid alkali activator promotes the dissolution of silicon and aluminum elements in the aluminosilicate raw materials and their gradual polymerization to form the main products of the single-component alkali-activated engineering slag soil polymer, such as hydrated calcium aluminosilicate and hydrated sodium aluminosilicate. This invention uses a solid alkali activator in a low dosage, and when used in conjunction with other raw materials, the single-component alkali-activated engineering slag soil polymer exhibits excellent compressive strength.

[0061] The raw materials for preparing the single-component alkali-activated engineering waste geopolymer provided by this invention, based on the mass fraction of the solid waste, include 30-35 parts of water (i.e., a water-to-solid ratio of 0.3-0.35). In specific embodiments, this can be 30, 30, 31, 32, 33, 34, or 35 parts. Water mainly acts as a reaction medium during the preparation of the geopolymer, participating in the dissolution of the geopolymer raw materials and the gel formation process. However, all the water is discharged after the reaction, and the geopolymer ultimately forms an anhydrous or low-water three-dimensional network structure. The water-to-solid ratio in the raw materials for preparing the single-component alkali-activated engineering waste geopolymer provided by this invention can be as low as 0.3. Due to the reduced amount of added water, the pores formed after water evaporation are relatively small, which is beneficial for improving the compressive strength of the single-component alkali-activated engineering waste geopolymer.

[0062] In this invention, the 3-day (3d) compressive strength of the single-component alkali-activated engineering slag soil polymer is preferably >21MPa, more preferably 21.5-65.0MPa, and in specific embodiments can be 21.5MPa, 37.6MPa, 38.3MPa, 38.6MPa, 41.3MPa, 42.3MPa, 43.9MPa, 44.5MPa, 45.7MPa, 46.6MPa, 48.6MPa, 49.0MPa or 65.0MPa.

[0063] In this invention, the 7-day (7-day age) compressive strength of the single-component alkali-activated engineering slag soil polymer is preferably >41 MPa, more preferably 41.2-71.8 MPa, and in specific embodiments can be 41.2 MPa, 44.7 MPa, 45.4 MPa, 50.4 MPa, 52.2 MPa, 53.0 MPa, 55.0 MPa, 55.5 MPa, 56.6 MPa, 58.8 MPa, 59.3 MPa, 69.5 MPa, or 71.8 MPa.

[0064] In this invention, the 28-day (28-day age) compressive strength of the single-component alkali-activated engineering slag soil polymer is preferably >51.5 MPa, more preferably 51.8-80.7 MPa, and in specific embodiments can be 51.8 MPa, 56.3 MPa, 58.2 MPa, 59.5 MPa, 60.5 MPa, 61.6 MPa, 63.2 MPa, 64.9 MPa, 65.3 MPa, 66.2 MPa, 71.5 MPa, 76.1 MPa, 76.9 MPa or 80.7 MPa.

[0065] This invention also provides a method for preparing the single-component alkali-activated engineering slag soil polymer described in the above technical solution, comprising the following steps:

[0066] The raw material to be calcined is calcined to obtain calcined material; when the calcination temperature is ≤800℃, the raw material to be calcined is a mixture of engineering slag and alkali metal salt flux; when the calcination temperature is >800℃, the raw material to be calcined is engineering slag, or a mixture of engineering slag and alkali metal salt flux.

[0067] The calcined material, slag, solid alkali activator and water are mixed to obtain geopolymer slurry;

[0068] After molding and curing the geopolymer slurry, a single-component alkali-activated engineering slag soil polymer is obtained.

[0069] The present invention calcines the raw material to be calcined to obtain calcined material; when the calcination temperature is ≤800℃, the raw material to be calcined is a mixture of engineering slag and alkali metal salt flux; when the calcination temperature is >800℃, the raw material to be calcined is engineering slag, or a mixture of engineering slag and alkali metal salt flux.

[0070] In this invention, the calcination temperature is preferably 550–950°C, and in specific embodiments it can be 550°C, 600°C, 650°C, 700°C, 750°C, 800°C, 850°C, 900°C, or 950°C; the heating rate from room temperature to the calcination temperature is preferably 4–7°C / min, and in specific embodiments it can be 4°C / min, 5°C / min, 6°C / min, or 7°C / min; the holding time for calcination is preferably 2 hours; the calcination is preferably carried out in a muffle furnace.

[0071] When construction waste soil is calcined together with alkali metal carbonates, the aluminosilicate minerals (such as kaolin and quartz) in the construction waste soil undergo a high-temperature solid-phase reaction with the alkali metal carbonates to generate compounds such as sodium silicate (Na₂SiO₂) and sodium aluminate (NaAlO₂), releasing carbon dioxide (CO₂). Sodium oxide further reacts with silicon dioxide (SiO₂) and aluminum oxide (Al₂O₂) in the construction waste soil to form sodium silicate and sodium aluminate. This process not only activates the inert components in the construction waste soil, transforming them into more reactive substances, but also improves the physicochemical properties of the construction waste soil, making it more suitable as a building material or industrial raw material. Furthermore, organic impurities and harmful substances are decomposed or volatilized during the calcination process, thereby reducing the environmental hazards of the construction waste soil. Sulfur trioxide (SO₂) produced by the decomposition of alkali metal sulfates may react with alkaline components (such as calcium oxide, CaO) in the construction waste soil to generate calcium sulfate (CaSO₄). This process not only activates the inert components in construction waste and improves its physicochemical properties, but may also introduce sulfate minerals, affecting the subsequent utilization performance of the construction waste. During calcination, organic impurities and harmful substances in the construction waste are also decomposed or volatilized, thereby reducing environmental hazards.

[0072] After the calcination is completed, the present invention preferably further includes cooling the calcined system to room temperature to obtain the calcined material. In the present invention, the cooling preferably includes natural cooling.

[0073] After obtaining the calcined material, the present invention mixes the calcined material, slag, solid alkali activator and water to obtain geopolymer slurry.

[0074] In this invention, mixing the calcined material, slag, solid alkali activator, and water preferably includes: a first mixing of the calcined material, slag, and solid alkali activator to obtain a dry material; and a second mixing of the dry material and water. In this invention, the rotation speed of the first mixing is preferably 30-60 r / min, and in specific embodiments, it can be 30 r / min, 35 r / min, 40 r / min, 45 r / min, 50 r / min, 55 r / min, or 60 r / min; the first mixing time is preferably 1-2 min, and in specific embodiments, it can be 1 min, 1.5 min, or 2 min. In this invention, the rotation speed of the second mixing is 100-150 r / min, and in specific embodiments, it can be 100 r / min, 110 r / min, 120 r / min, 130 r / min, 140 r / min, or 150 r / min; the second mixing time is preferably 1-3 min, and in specific embodiments, it can be 1 min, 1.5 min, 2 min, 2.5 min, or 3 min. The above-mentioned mixing method of the present invention can improve the dispersibility and hydration reaction of dry materials, thereby improving the uniformity, chemical stability (corrosion resistance, carbonization resistance, etc.), physical stability (volume stability, impermeability, etc.), thermal stability and durability of the materials.

[0075] After obtaining the geopolymer slurry, the present invention performs molding and curing on the geopolymer slurry to obtain a single-component alkali-activated engineering slag soil polymer.

[0076] In this invention, the molding is preferably carried out in a mold. Specifically, the geopolymer slurry is injected into the mold in layers, compacted, sealed, and then demolded to obtain a single-component alkali-activated engineering slag soil polymer gel.

[0077] This invention does not impose any special limitations on the material and size of the mold; they can be determined according to actual needs. In this invention, the mold is preferably cleaned before use, adhesive tape is applied to the contact surfaces, and a release agent is applied to the mold walls to facilitate the demolding of the single-component alkali-activated engineering waste soil polymer. This invention does not impose any special limitations on the release agent; any release agent well-known to those skilled in the art can be used.

[0078] The present invention preferably places the mold on a vibrating table first, then injects the geopolymer slurry into the mold, vibrates it, and then compacts it until the surface of the geopolymer slurry in the mold is flat and smooth.

[0079] In this invention, the sealing is preferably achieved using a plastic wrap sealant. This invention prevents the alkaline surface of the geopolymer slurry and the single-component alkali-activated engineering waste soil polymer from reacting with CO2 in the air to form carbonates and undergo carbonation; it also prevents surface drying and shrinkage caused by moisture evaporation, which can lead to cracking.

[0080] In this invention, the molding temperature is preferably 23-27°C, and in specific embodiments it can be 23°C, 24°C, 25°C, 26°C or 27°C; the relative humidity during molding is preferably 92-98%, and in specific embodiments it can be 92%, 93%, 94%, 95%, 96%, 97% or 98%; the molding time is preferably 23-25 ​​hours, and in specific embodiments it can be 23 hours, 23.5 hours, 24 hours, 24.5 hours or 25 hours; the molding is preferably static molding; the molding is preferably carried out in a constant temperature and humidity curing chamber.

[0081] In this invention, the curing temperature is preferably 23-27°C, and in specific embodiments, it can be 23°C, 24°C, 25°C, 26°C, or 27°C; the relative humidity during curing is preferably 92-98%, and in specific embodiments, it can be 92%, 93%, 94%, 95%, 96%, 97%, or 98%; the curing time is preferably 1-28 days, and in specific embodiments, it can be 1 day, 2 days, 4 days, 6 days, 10 days, 12 days, 15 days, 20 days, 22 days, 25 days, 27 days, or 28 days; the curing is preferably carried out in a constant temperature and humidity curing chamber.

[0082] The present invention also provides the application of the single-component alkali-activated engineering slag soil polymer described in the above technical solution or the single-component alkali-activated engineering slag soil polymer prepared by the preparation method described in the above technical solution as a building material.

[0083] This invention uses engineering waste soil and slag as main raw materials, and utilizes alkali activation technology and controls the proportions of each raw material to obtain a high-strength, single-component alkali-activated engineering waste soil polymer with a small amount of alkali activator. This invention achieves high strength without the need for external reinforcing agents (such as fibers). The single-component alkali-activated engineering waste soil polymer provided by this invention has excellent application prospects as a building material. Moreover, by using engineering waste soil and slag as main raw materials, this invention consumes a large amount of different types of solid waste while conserving significant natural resources and achieving low-carbon emission reduction.

[0084] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, of the single-component alkali-activated engineering slag soil polymer, its preparation method, and its application, should not be construed as limiting the scope of protection of the present invention.

[0085] In the following examples and comparative examples, the excavated soil cake comes from the underground engineering excavation site, according to... Figure 5The flowchart shown illustrates that the engineering waste soil cake is dried at 60℃, ground into powder using a grinding mill, passed through an 80-mesh standard sieve, and the portion of engineering waste soil that passes through the sieve is directly placed into a muffle furnace for calcination to obtain calcined engineering waste soil. Figure 1 The images show the actual construction waste after drying (left) and after grinding and sieving (right). Figure 2 The image shows actual slag from the calcination project. Figures 1-2 It can be seen that after calcination alone, the construction waste soil changes from yellowish-brown to light brown, and the particles are relatively dispersed. The XRD pattern of the construction waste soil is shown below. Figure 3 ,Depend on Figure 3 It can be seen that the construction waste mainly contains quartz, kaolinite, and illite. The SEM image of the construction waste is shown below. Figure 4 The left image is magnified 3000 times, and the right image is magnified 30000 times. Figure 4 It can be seen that the surface morphology of the engineering waste soil particles is relatively rough, mainly consisting of stacked sheet-like structures. There are irregular microscopic gaps and protrusions between the particles. At the same time, it can be observed that the sample has a large number of agglomerates, with particles surrounding them. The agglomerates are arranged non-directionally, mainly in the form of edge-to-face and surface-to-face formations. The contact is relatively loose, and the outer particles do not have a clear directional distribution pattern.

[0086] according to Figure 5 The flowchart shown illustrates how the sieved portion of the engineering slag is mixed with an alkali metal salt flux and then calcined in a muffle furnace to obtain the calcined feedstock. Example 3 shows the calcined feedstock as follows: Figure 6 As shown, by Figure 6 It can be seen that the slag and alkali metal flux, when calcined together, form relatively dense lumps. The SEM image of the slag is shown below. Figure 7 The left image is magnified 500 times, and the right image is magnified 1000 times. Figure 7 It can be seen that the surface of the slag raw material is flat, and it consists of blocky particles and is an amorphous glassy substance.

[0087] The particle size of the sieved engineering waste soil is less than 10 μm. The main chemical components obtained by XRF analysis are shown in Table 1.

[0088] Table 1. Main chemical components (wt%) of engineering waste soil

[0089] Element <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> MgO CaO <![CDATA[TiO2]]> <![CDATA[Na2O]]> <![CDATA[SO3]]> Cl <![CDATA[P2O5]]> MnO content 56.65 33.15 3.35 2.71 1.52 0.94 0.50 0.46 0.24 0.18 0.09 0.03

[0090] The slag was selected from Guangdong Shaogang Company, with a preferred strength grade of S95 and a density of 2.5 g / cm³. 3 The quality meets the requirements of GB / T18046-2008, with a particle size of 50-1000 nm; the main chemical components of the slag obtained by XRF analysis are shown in Table 2.

[0091] Table 2. Main chemical components of slag (wt%)

[0092] Element <![CDATA[SiO2]]> CaO <![CDATA[Al2O3]]> MgO <![CDATA[K2O]]> <![CDATA[Na2O]]> <![CDATA[Fe2O3]]> <![CDATA[SO3]]> <![CDATA[TiO2]]> MnO content 30.61 39.84 16.91 9.06 0.28 0.29 0.22 1.59 0.69 0.26

[0093] Water glass: modulus 2.0, density 1.44 g / cm³ 3 The alkali content of water glass = mass of Na2O in water glass / (mass of engineering waste soil + mass of mineral powder) × 100%.

[0094] Preparation of calcined product (denoted as product A): Na2CO3 and SiO2 were mixed evenly at a molar ratio of 1:1.5, heated to 800℃ at a rate of 5℃ / min, and calcined for 2 hours, then cooled to room temperature.

[0095] The proportion of construction waste soil mixed in = the mass of construction waste soil / (mass of construction waste soil + mass of slag) × 100%.

[0096] Water-to-solid ratio = Mass of added water / (Mass of construction waste + Mass of slag).

[0097] The amount of alkali used in alkali metal salt fluxing agent = mass of alkali metal salt fluxing agent Na2O / (mass of engineering waste soil + mass of slag) × 100%.

[0098] The amount of alkali used in the alkali activator = the mass of Na2O in the alkali activator / (mass of engineering waste soil + mass of slag) × 100%.

[0099] Compressive strength test method: According to GB / T17671-1999 standard, the compressive strength test of polymer in engineering slag soil base is 40mm×40mm×40mm, the loading speed is 2.4kN / s, and the testing machine used is Wuxi Zhongke Building Materials Strength Testing Machine; in order to ensure the accuracy of the results, the average value of three parallel tests is taken as the final data result.

[0100] Examples 1-15 and Comparative Examples 1-13

[0101] The raw material usage for Examples 1-15 and Comparative Examples 1-13 is shown in Table 3, according to... Figure 5 The flowchart shown illustrates the preparation method of a single-component alkali-activated polymer from engineering waste soil: Engineering waste soil is crushed using a pulverizer and passed through an 80-mesh standard sieve. The undersize portion is dried in an oven at 80°C. The dried engineering waste soil and alkali metal salt flux are placed in a muffle furnace and heated to the calcination temperature (see Table 3) at a rate of 5°C / min, then held at that temperature for 2 hours. Afterward, it is naturally cooled to room temperature to obtain the calcined material. Examples 1-2, 7-11, Comparative Examples 6-8, and Comparative Example 11 do not include alkali metal salt flux.

[0102] The calcined material, slag, and alkali activator were stirred at a low speed of 60 r / min for 2 min, then water was added, and the mixture was stirred at a high speed of 120 r / min for 3 min to obtain a geopolymer slurry.

[0103] The geopolymer slurry was injected in layers into a 40mm×40mm×40mm cubic triple mold and a 40mm×40mm×160mm rectangular triple mold placed on a vibrating table. Vibration was performed simultaneously with slurry injection until the surface of the sample in the mold was smooth and flat. The mold was then sealed with plastic wrap and placed in a constant temperature and humidity curing chamber at 25±2℃ and 95% relative humidity for 24 hours before demolding to obtain the engineering waste soil-based geopolymer gel (sample). The engineering waste soil-based geopolymer gel was cured in the same constant temperature and humidity chamber for 2 days, 6 days, and 27 days to obtain single-component alkali-activated engineering waste soil polymers at different ages (3 days, 7 days, and 28 days). Before use, adhesive tape was applied to the contact surfaces of the cubic and rectangular triple molds, and a release agent was applied to the mold walls to facilitate demolding.

[0104] Table 3. Raw materials and compressive strength test results for the preparation of single-component alkali-activated engineering waste soil polymers in the examples and comparative examples.

[0105]

[0106]

[0107] Note: "-" indicates that the strength could not be measured due to low strength.

[0108] Figure 8 The image shows a physical sample of the single-component alkali-activated engineering slag polymer prepared in Comparative Example 8 during the test of compressive strength. It can be seen that when water glass is used as the activator, the strength of the sample is too low and it is directly crushed, making it impossible to measure the strength.

[0109] Table 3 shows that when the calcination temperature is 950℃, with other parameters being the same and only the alkali activator differing, the compressive strength of the single-component alkali-activated engineering waste soil polymer using a solid alkali activator is higher than that using liquid water glass. Furthermore, the compressive strength is relatively low when the engineering waste soil content is 80%, while the 28-day compressive strength reaches 53.2 MPa when the content is 70%. This content not only maintains a high compressive strength but also achieves the goal of consuming a large amount of engineering waste soil.

[0110] When the calcination temperature is 800℃, adding flux during the calcination of engineering waste soil can yield specimens with a 28-day strength as high as 64.9MPa. Even if no flux is added during the calcination of engineering waste soil, the compressive strength of the specimens using solid alkali activators is still higher than that of the specimens using liquid water glass, and the total alkali content is only 6%.

[0111] When the calcination temperature is 750℃, although the calcination temperature is lower than 800℃, due to the addition of flux during the calcination of engineering waste soil, a specimen with a 28-day strength of up to 56.3MPa can still be obtained when using a solid alkali activator. Even if no flux is added during the calcination of engineering waste soil, the compressive strength of the specimen using a solid alkali activator is still higher than 10MPa, and the total alkali content is only 6%.

[0112] When the calcination temperature is 550℃, which is much lower than 800℃, a test block with a 28-day strength of up to 49.8MPa can still be obtained by adding flux during the calcination of engineering slag and using solid alkali activator, and the total alkali content is only 6%.

[0113] As can be seen from the above embodiments and comparative examples, this invention uses engineering waste soil and slag as geopolymer materials, and by controlling the amount of engineering waste soil, alkali content, water-to-solid ratio, etc., successfully develops a geopolymer with considerable compressive strength. While fully utilizing engineering waste soil, it can also reduce CO2 emissions, lower costs, and conserve resources.

[0114] This invention utilizes a solid alkali activator to synergistically activate slag and engineering waste soil, achieving highly efficient geopolymer preparation. Under alkali activation conditions, slag rapidly releases silica-alumina monomers and calcium ions, promoting the formation of hydrated calcium aluminosilicate gel and providing strength support for the formation of the geopolymer's three-dimensional network structure. Simultaneously, engineering waste soil releases some active silica-alumina monomers under alkali activation, and the calcium ions dissolved from the slag further activate the kaolinite component in the engineering waste soil, promoting the formation of hydrated sodium aluminosilicate gel. Although the volume stability of the single-component alkali-activated engineering waste soil geopolymer with excessive slag content is poor and prone to microcracks, the slower reaction of engineering waste soil particles in the early stages effectively fills the pores, alleviating the volume mismatch problem caused by the rapid reaction of slag, thereby enhancing the compressive strength of the geopolymer. In an alkaline environment, even with only 20% slag and 80% engineering waste soil added, the compressive strength of the single-component alkali-activated engineering waste soil geopolymer reaches 16.60 MPa at 28 days, demonstrating excellent mechanical properties and resource utilization value.

[0115] Figure 9 The electron spectra of C1S, O1S, Si2P, and Al2P of the single-component alkali-activated engineering slag soil polymers (3-day age) prepared in Examples 2-4 are shown. C1S spectrum analysis revealed a characteristic CC peak at 284.80 eV in all samples; however, the binding energy of the COC bond varied significantly depending on the composition: OC3N (286.19 eV) exhibited a typical ether bond, 3A3N (287.58 eV) showed an increased binding energy, and 3A3M (285.36 eV) showed a decreased binding energy; furthermore, all samples showed a CO3 peak at approximately 289.3 eV. 2-The presence of carboxyl peaks indicates the presence of oxidation products on the surface. O 1s spectrum analysis shows that the sample prepared in Example 2 is mainly composed of carbonate and CO bonds, while the CO bond binding energy of the samples prepared in Examples 3 and 4 is reduced, and alumina is formed in the sample prepared in Example 3. Si 2p spectrum analysis shows that the sample prepared in Example 2 is mainly composed of SiO2 and SO4. 2- The presence of residual SiO2 in the sample indicates that the reaction was incomplete. The samples prepared in Examples 3 and 4, due to a more complete reaction, formed an aluminosilicate (Al-O-Si) structure, resulting in a decrease in the Si 2p binding energy. 2- The peaks remained stable in all three samples. These results, along with the C1s and O1s data, indicate that aluminum doping significantly altered the silicon-oxygen network structure of the material. Al 2p spectral analysis showed that aluminum existed as a mixed phase of aluminosilicate and alumina in the sample prepared in Example 2, indicating that aluminum was not fully integrated into the silicon-oxygen network. In Examples 3 and 4, the aluminosilicate peak was dominant, while the alumina peak was weakened, indicating that nitrogen or metal doping optimized the integration of aluminum, forming a more stable Al-O-Si structure. Combining the Si 2p and O1s data, it can be inferred that the formation of aluminosilicate increased, reducing free alumina. These results are consistent with the previously analyzed Si 2p and O1s data, jointly revealing the synergistic regulatory effect of doping on the material structure.

[0116] Figure 10 The single-component alkali-activated engineering slag soil polymers (28 days old) of Examples 1, 3, and 14 29 SiNMR and 27 AlNMR spectrum.

[0117] Example 1: Preparation of a single-component alkali-activated engineering slag soil polymer 29 The Si spectral peaks are concentrated in the range of -90 to -110 ppm, with the main peak near -100 ppm corresponding to highly polymerized Q. 4 The (SiO4) structure indicates that silicon is mainly composed of tetra-coordinated bridging oxygens, forming a dense silicon-oxygen network; while the shoulder peak near -90ppm may originate from Q. 3 The (SiO3(OH)) structure indicates the presence of a small number of silanol groups or terminal defects. The spectral characteristics are similar to those of undoped pure silicon dioxide or silicate glass, showing a high degree of silicon-oxygen network integrity.

[0118] Example 3 29 The Si peaks generally shift towards higher fields (e.g., -80 to -100 ppm), Q 4 The peak intensity decreased, while a new signal appeared near -80ppm, which can be attributed to Q. 2 (SiO2(OH)2) or Al-O-Si structure. This change indicates a decrease in the degree of polymerization of the silicon-oxygen network, possibly due to aluminum doping (Al).3+ Replace Si 4+ This leads to the breaking of silicon-oxygen bonds, forming more non-bridged oxygen or aluminosilicate units. Furthermore, the shift in chemical shift also suggests an increase in electron density around silicon, possibly related to nitrogen doping (such as Si-N bonds) or local charge compensation effects.

[0119] Example 14: Preparation of a single-component alkali-activated polymer from engineering waste soil 29 The Si spectrum is more complex, with peak positions further broadened to -70 to -120 ppm. Besides Q... 4 / Q 3 / Q 2 Besides the silicon-oxygen peaks, characteristic peaks of Si-N bonds may appear near -60 ppm (typically located between -40 and -60 ppm), while peaks between -70 and -80 ppm may correspond to metal-silicate (Si-OM) structures. This coexistence of multiple peaks indicates that the chemical environment of silicon in this sample is highly heterogeneous, possibly containing nitrogen doping, metal modification, and partially depolymerized silicon-oxygen clusters simultaneously. Broad peaks may suggest amorphous enhancement or increased local disorder.

[0120] In summary, from Examples 1→3→14, the coordination state of silicon gradually changes from the highly polymerized Q state. 4 Structure towards lower degree of polymerization (Q) 3 / Q 2 The evolution can be either a transition to heteroatom bonding (Si-N, Si-OM). This evolution may be closely related to aluminum / nitrogen co-doping, metal introduction, or differences in synthesis temperature, leading to the evolution of silicon-oxygen networks from rigid to more open chemical structures.

[0121] Example 1: Preparation of a single-component alkali-activated engineering slag soil polymer 27 The Al spectrum shows a sharp symmetrical peak at 60 ppm, indicating that aluminum is regularly integrated into the silicon-oxygen network in a single tetracoordinate [AlO4] form, forming a well-crystallized aluminosilicate structure.

[0122] Example 3: Single-component alkali-activated engineering slag soil polymer prepared 27 The Al spectrum shows obvious changes: the [AlO4] peak at 60 ppm is significantly broadened, while five-coordinate [AlO5] and six-coordinate [AlO6] characteristic peaks appear in the 30 ppm and 0-10 ppm regions, respectively. This multi-coordinate coexistence state may be due to the coordination field distortion caused by nitrogen doping or the increase in coordination number caused by special heat treatment conditions.

[0123] Example 14: Preparation of a single-component alkali-activated polymer from engineering waste soil 27The Al spectrum has become further complex, with the [AlO4] peak continuing to broaden and the [AlO5] and [AlO6] peaks showing significant intensities. A weak signal also appeared in the -10 to -20 ppm range, suggesting the possible presence of aluminum species with special coordination environments. This transition from a single four-coordinate system to a multi-coordinate mixed state ([AlO4]→[AlO4]+[AlO5]+[AlO6]) reflects the profound influence of preparation conditions on the local structure of aluminum: the introduction of dopants (such as nitrogen) disrupts the original coordination symmetry, while high-temperature treatment may promote the formation of high-coordinate aluminum. This diversity of coordination states will directly affect the distribution of acidic sites, structural stability, and catalytic performance of the material, compared to previous studies. 29 Si NMR reveals the depolymerization of the silicon-oxygen network (Q). 4 →Q 3 / Q 2 These findings corroborate each other and jointly reveal the structure-property relationship between doping, structure, and properties.

[0124] The TIMA (Tescan Integrated Mineral Analyzer) system is a fully automated quantitative mineral analysis system based on scanning electron microscopy. It identifies mineral phases by combining BSE and EDS signals, and then uses TIMA analysis software to segment these phases, thereby obtaining basic rock and mineral information such as mineral type and content, distribution, grain size, degree of liberation, elemental content, and occurrence. TIMA testing was performed on single-component alkali-activated engineering waste soil polymers prepared in Examples 1, 3, and 28 with a curing age of 28 days. The results are shown in the table below. Figure 11 , Figure 12 , Figure 13 And Table 4, Figures 11-13 The legend for the middle image in the first row is shown at the bottom.

[0125] Table 4. TIMA results of the single-component alkali-activated engineering waste soil polymers prepared in Examples 1, 3, and 28 with a curing age of 28 days.

[0126]

[0127] Depend on Figures 11-13 As shown in Table 4, in Examples 3 and 14, the addition of Na2SO4 during calcination resulted in the reaction of Na2SO4 with a small amount of CaO in the slag to form calcium aluminosilicates. In Example 1, no Na2SO4 was added during calcination, resulting in the formation of less calcium aluminosilicates. In Example 3, due to the higher calcination temperature (950℃), more Na2SO4 was decomposed, leading to the production of more Na2O or Na +As a result, more sodium potassium aluminosilicates and sodium feldspar are produced; in Example 3, due to the higher calcination temperature and the addition of Na2SO4 during calcination, the reaction with the slag soil is more extensive and complete, resulting in the lowest mass of matrix in the reaction products. Furthermore, since the slag soil contains a certain amount of quartz, the remaining unreacted quartz content in Example 3 is the lowest.

[0128] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A single-component alkali-activated engineering waste soil polymer, characterized in that, The raw materials for preparation, by mass, include: 100 parts solid waste; 0-6 parts alkali metal salt flux; 3-6 parts solid alkali activator (calculated as sodium oxide); and 30-35 parts water. By mass percentage, the solid waste comprises 50-70% engineering waste and 30-50% slag; The alkali metal salt flux is one or more of alkali metal sulfates and alkali metal carbonates; The solid alkali activator is Na2SiO3 and / or calcined product, wherein the calcined product is a calcined product of Na2CO3 and SiO2; The engineering waste soil is calcined before use. When the calcination temperature is ≤800℃, the amount of alkali metal salt flux is not 0 and it is mixed with the engineering waste soil before calcination.

2. The single-component alkali-activated engineering waste soil polymer according to claim 1, characterized in that, The particle size of the engineering waste soil is ≥80 mesh.

3. The single-component alkali-activated engineering waste soil polymer according to claim 1, characterized in that, The particle size of the slag is 50~1000nm.

4. The method for preparing the single-component alkali-activated engineering slag soil polymer according to any one of claims 1 to 3, characterized in that, Includes the following steps: The raw material to be calcined is calcined to obtain calcined material; when the calcination temperature is ≤800℃, the raw material to be calcined is a mixture of engineering slag and alkali metal salt flux; when the calcination temperature is >800℃, the raw material to be calcined is engineering slag, or a mixture of engineering slag and alkali metal salt flux. The calcined material, slag, solid alkali activator and water are mixed to obtain geopolymer slurry; After molding and curing the geopolymer slurry, a single-component alkali-activated engineering slag soil polymer is obtained.

5. The preparation method according to claim 4, characterized in that, The calcination temperature is 550~950℃, and the holding time is 100~150min.

6. The preparation method according to claim 4, characterized in that, The mixing process includes: first mixing the calcined material, slag, and solid alkali activator to obtain a dry material; second mixing the dry material with water; the first mixing speed is 30~60 r / min and the time is 1~2 min; the second mixing speed is 100~150 r / min and the time is 1~3 min.

7. The preparation method according to claim 4, characterized in that, The molding temperature is 23~27℃, the relative humidity is 92~98%, and the time is 23~25h; the molding includes static molding. The curing temperature is 23~27℃, the relative humidity is 92~98%, and the time is 1~28 days.

8. The application of the single-component alkali-activated engineering slag soil polymer according to any one of claims 1 to 3 or the single-component alkali-activated engineering slag soil polymer prepared by the preparation method according to any one of claims 4 to 7 as a building material.

Images