Steel slag activity exciting agent, steel slag cementing material and preparation method of steel slag activity exciting agent and steel slag cementing material

Abstract

The invention relates to the technical field of solid waste steel slag recycling, in particular to a steel slag activity exciting agent, a steel slag cementing material and a preparation method of the steel slag activity exciting agent. The steel slag activity exciting agent comprises the following raw materials in percentage by mass: 35-45% of rice hull ash or activated rice hull ash, 20-30% of ardealite, 15-25.5% of water glass, 9-12% of sodium hydroxide and the balance of an alcohol amine activating agent. The steel slag activity exciting agent is applied to preparation of a steel slag cementing material. The steel slag cementing material is prepared from the steel slag activity exciting agent and steel slag micro-powder, and the mass ratio of the steel slag activity exciting agent to the steel slag micro-powder is (8-16): 100. A rice hull ash-gypsum-water glass ternary solid waste synergistic excitation steel slag system is provided for the first time, the problem of slow early hydration of the steel slag is solved through compounding of an alcohol amine activator, water glass and sodium hydroxide, and high value-added utilization of the steel slag replacing 30-50% of cement is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of solid waste steel slag recycling, and in particular to a steel slag activity activator and a steel slag gelling material and a preparation method thereof. Background Art

[0002] Steel slag is a solid waste generated during the steelmaking process. It not only occupies land resources but also causes water and soil pollution, posing a serious threat to ecological and environmental safety. Steel slag has the characteristics of high bulk density, high strength, high hardness, and good wear resistance. Using it as a road fill material not only improves the bearing capacity of the roadbed (embankment), but also enables large-scale utilization of steel slag, further implementing the national "dual carbon" strategy for the comprehensive utilization of bulk solid waste. This will help alleviate the large demand for stone materials in highway construction and help solve the practical problems of steel slag storage and environmental protection for enterprises.

[0003] However, this extensive slag utilization method also results in a certain degree of resource waste. This is because the main mineral components of steel slag include tricalcium silicate (C3S), dicalcium silicate (C2S), calcium forsterite ([Ca,Mg]2SiO4), RO phase minerals (such as FeO), and small amounts of free calcium oxide (f-CaO) and free magnesium oxide (f-MgO). If it is redeveloped as a substitute for cement clinker, it will not only significantly increase the added value of steel slag recycling, but also reduce energy consumption, resource waste, and greenhouse gas emissions generated during cement production.

[0004] While the mineral composition of steel slag and cement clinker is similar, the former's primary minerals, C3S and C2S, are formed at the high temperatures of steelmaking. Their crystal lattices are intact, their grains are large, and after rapid cooling, they form a vitreous structure, resulting in extremely low hydration activity. Therefore, achieving high-quality and efficient improvements in the cementitious properties of steel slag through the synergistic activation of multiple components remains a critical technical bottleneck in this field. Summary of the Invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a steel slag activity activator and a steel slag gelling material and a preparation method thereof.

[0006] A steel slag activation activator comprises the following raw materials by mass percentage: 35-45% rice husk ash or activated rice husk ash, 20-30% phosphogypsum, 15-25.5% water glass, 9-12% sodium hydroxide, and the balance being an alcoholamine activator.

[0007] Preferably, phosphogypsum is an industrial by-product with a pH of 3.2-3.6 and a relative density of 2.1-2.5 g / cm 3 .

[0008] Preferably, the water glass is an industrial-grade water glass with a modulus of 3.2, a Na2O content of 7.5%, and a SiO2 content of 28.0%.

[0009] Preferably, the alkanolamine activator is triethanolamine, N-methyldiethanolamine, or / and triisopropanolamine.

[0010] Preferably, the rice husk ash is prepared by the following steps: immersing the rice husks in an acidic solution for 1-2 h; rinsing with clear water until neutral, drying at a low temperature of 50-60 °C for 22-26 h, calcining at 650 ± 10 °C for 2-4 h, and grinding and sieving after cooling.

[0011] The main component of the rice husk ash is silica. Through acid leaching pretreatment, metal elements such as K, Na, and Ca in the rice husks can be dissolved out, increasing the silica content in the rice husk ash to over 90%; after high-temperature calcination at 650 ± 10 °C (if the temperature is too high, it will cause the crystal form transformation of silica and reduce the activity), the silica in the rice husk ash is in an amorphous state and has a porous structure, with high activity; after grinding, its reaction activity is further increased, and it is prone to volcanic ash reaction to form gel products in an alkaline environment.

[0012] More preferably, the acidic solution is an acetic acid aqueous solution or hydrochloric acid, the volume fraction of the acidic solution is 1.0-5.0%, and the mass ratio of the rice husks to the acidic solution is 1:48-52.

[0013] Preferably, the activated rice husk ash is prepared by the following steps: adding dendritic amino-terminated polyamide-amine, silane coupling agent, and dodecyl polyoxyethylene ether to water and stirring for 10-30 min, adding the rice husk ash thereto and performing ultrasonic treatment for 1-2 h, heating to 120-140 °C for heat treatment for 5-15 min, cooling to room temperature, filtering, washing, and drying under vacuum.

[0014] In the present invention, amino-terminated polyamide-amine is grafted onto the rice husk ash, so that in an alkaline condition, the amino groups at the ends of the obtained activated rice husk ash will be deprotonated to form amino anions, which can not only combine with positively charged calcium ions, cooperate with amorphous silica to accelerate the formation of a gel network, and bind to the system with its dendritic structure, significantly enhancing the compressive strength of the product.

[0015] More preferably, the mass ratio of the dendritic amino-terminated polyamide-amine, silane coupling agent, dodecyl polyoxyethylene ether, and rice husk ash is 1-2:1-2:1-2:10-20.

[0016] The above steel slag activity activator is used in the preparation of steel slag cementitious materials.

[0017] A steel slag cementitious material, the raw materials of which include: the above steel slag activity activator and steel slag powder, and the mass ratio of the steel slag activity activator to the steel slag powder is 8-16:100.

[0018] Preferably, the particle size of the steel slag fine powder is ≤ 0.5 mm, and the specific surface area is ≥ 400 m 2 / kg.

[0019] The preparation method of the above-mentioned steel slag cementitious material comprises the following steps: premixing water glass and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 105 - 170 °C for 4 - 5 h, and then grinding it to D 50 < 50 μm; then adding rice husk ash or activated rice husk ash and steel slag fine powder for dry mixing, and then adding the premixed material and an alcohol amine activator for stirring.

[0020] After the phosphogypsum is dehydrated, it is converted into β-type hemihydrate gypsum, and after grinding, β-type hemihydrate gypsum powder with a specific surface area of ≥ 250 m 2 / g can be obtained. In the present invention, phosphogypsum is used as an activator raw material, which is converted into hemihydrate gypsum by heating, with an increased specific surface area. When it meets water, it rapidly hydrates to regenerate dihydrate gypsum and releases heat, and the ion dissolution rate is accelerated, resulting in the temperature rise of the steel slag activation system, further promoting the formation of C-S-H gel and ettringite (AFt); SO4 2- The rapid release enables the uniform nucleation of AFt in the slurry, forming an intertwined needle-like structure, closely coexisting with the C-S-H gel, significantly reducing the porosity of the material, and improving the mechanical properties of the activated steel slag system.

[0021] The present invention innovatively proposes a "solid waste-based composite activation - multiphase synergistic enhancement" technical route. Through the complexation of amorphous SiO2 in rice husk ash, SO4 in phosphogypsum 2- and the alcohol amine activator, the directional dissolution of active components in the steel slag and the orderly growth of cementitious products are realized. The key technological breakthroughs include:

[0022] (1) Pretreatment of rice husk ash: The combined technology of acid leaching - calcination increases the content of amorphous SiO2 to more than 90%, and rapidly generates C-S-H gel with Ca 2+ in an alkaline environment; if the rice husk ash is further activated, polyamidoamine with terminal amino groups is grafted onto the rice husk ash, and its terminal amino groups will be deprotonated to form amino anions under alkaline conditions. It can not only combine with positively charged calcium ions, synergistically act with amorphous silica to accelerate the formation of the gel network, and combine with its dendritic structure in the system, significantly enhancing the compressive strength of the product;

[0023] (2) Activation of phosphogypsum: Gradient dehydration generates highly active β-type hemihydrate gypsum, synchronously providing SO4 2- and Ca 2+ , promoting the intertwined coexistence of AFt and C-S-H;

[0024] (3) Synergistic mechanism of alkanolamine activators: Chelate metal ions through -OH / -NH2 groups, reduce the ion concentration difference in the solution, continuously promote mineral dissolution, and accelerate the formation of the gel network as the nucleation sites of C-S-H.

[0025] Preferably, the temperature of the room temperature and high humidity environment is 20°C ± 2°C, and the humidity ≥ 95%.

[0026] Beneficial effects:

[0027] The present invention first proposes a ternary solid waste synergistic excitation steel slag system of rice husk ash - gypsum - water glass, and solves the problem of slow early hydration of steel slag by compounding alkanolamine activators with water glass and sodium hydroxide, realizing the high - value utilization of steel slag replacing 30 - 50% of cement, meeting the relevant requirements of "Steel Slag Powder for Cement and Concrete" (GB / T 20491 - 2006).

[0028] The hydroxyl group (-OH) and amino group (-NH or -NH2) of the alkanolamine activator and the amino group on the surface of the activated rice husk ash powder can form stable complexes with metal ions such as Ca 2+ 、Al 3+ and Fe 3+ dissolved from the steel slag, reducing the concentration of free ions in the solution and promoting the continuous dissolution of mineral phases (such as γ-C2S, etc.); at the same time, the complex adheres to the surface of the steel slag particles, weakening the Si-O-Si and Al-O-Al covalent bonds and promoting the release of active silicoaluminates. At the same time, part of the alkanolamine activator molecules hydrolyze in the solution to generate OH - , which can increase the pH value of the micro - region and accelerate the depolymerization of the vitreous network in the steel slag. Description of the drawings

[0029] Figure 1 It is a comparison chart of the setting times of the steel slag cementitious materials obtained in Examples 1 - 4 and Comparative Examples 1 - 3.

[0030] Figure 2 It is a comparison chart of the unconfined compressive strengths after 7 - day curing of the steel slag cementitious materials obtained in Examples 1 - 4 and Comparative Examples 1 - 3 when mixed with cement in different mass ratios.

[0031] Figure 3 It is a comparison chart of the unconfined compressive strengths after 28 - day curing of the steel slag cementitious materials obtained in Examples 1 - 4 and Comparative Examples 1 - 3 when mixed with cement in different mass ratios.

[0032] Figure 4 It is a comparison chart of the activity indices after 7 - day curing of the steel slag cementitious materials obtained in Examples 1 - 4 and Comparative Examples 1 - 3 when mixed with cement in different mass ratios.

[0033] Figure 5The figure shows the comparison of the activity indices of the steel slag cementitious materials obtained in Examples 1-4 and Comparative Examples 1-3 and cement after being mixed at different mass ratios and cured for 28 days.

[0034] Figure 6 The figure shows the comparison of the setting times of the steel slag cementitious materials obtained in Example 4, Example 5 and Comparative Example 4.

[0035] Figure 7 The figure shows the comparison of the unconfined compressive strengths after 7 days of curing of the steel slag cementitious materials obtained in Example 4, Example 5 and Comparative Example 4 and cement after being mixed at different mass ratios.

[0036] Figure 8 The figure shows the comparison of the unconfined compressive strengths after 28 days of curing of the steel slag cementitious materials obtained in Example 4, Example 5 and Comparative Example 4 and cement after being mixed at different mass ratios.

[0037] Figure 9 The figure shows the comparison of the activity indices after 7 days of curing of the steel slag cementitious materials obtained in Example 4, Example 5 and Comparative Example 4 and cement after being mixed at different mass ratios.

[0038] Figure 10 The figure shows the comparison of the activity indices after 28 days of curing of the steel slag cementitious materials obtained in Example 4, Example 5 and Comparative Example 4 and cement after being mixed at different mass ratios. Detailed implementation mode

[0039] The present invention will be further illustrated below in conjunction with specific embodiments.

[0040] The phosphogypsum used below is an industrial by-product, taken from a chemical fertilizer plant in Xuancheng City, with a pH value of 3.2-3.6 and a relative density of 2.1-2.5 g / cm 3 .

[0041] The water glass used below is an industrial-grade water glass with a modulus of 3.2, a Na2O content of 7.5%, and a SiO2 content of 28.0%, produced by Jiangsu Yanmou New Material Technology Co., Ltd.

[0042] The rice husks used below are sourced from Feixi County, Anhui Province.

[0043] The dendritic terminal amino polyamide amine used below is purchased from Hangzhou Mouqiao Biotechnology Co., Ltd., with a generation number of 4.0.

[0044] The steel slag powder used below is obtained by grinding steel slag powder that meets the performance requirements of GB / T 20491-2006 "Steel Slag Powder for Cement and Concrete", with a particle size ≤ 0.5 mm and a specific surface area ≥ 40 mu 2 / kg.

[0045] Example 1

[0046] A steel slag activity activator, the raw materials of which by mass percentage include: rice husk ash 45%, phosphogypsum 25%, sodium silicate 15%, sodium hydroxide (analytical pure) 12%, and the balance is N-methyldiethanolamine.

[0047] The rice husk ash is prepared by the following steps: soaking rice husks in an acetic acid aqueous solution with a volume fraction of 5.0% for 2 h, with a solid-liquid ratio of 1:50; rinsing with clear water until neutral, then placing in an oven at 60 °C for low-temperature drying for 26 h, then placing in a muffle furnace for calcination at 660 °C for 4 h, cooling and then grinding, and passing through a 0.075 mm sieve.

[0048] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activity activator and steel slag micro-powder, and the mass ratio of the steel slag activity activator to the steel slag micro-powder is 10:100.

[0049] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing sodium silicate and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 170 °C for 5 h, and then grinding to D 50 <50 μm; then adding rice husk ash and steel slag micro-powder for dry mixing, and then adding the premixed material and an alcohol amine activator for stirring.

[0050] Example 2

[0051] A steel slag activity activator, the raw materials of which by mass percentage include: rice husk ash 35%, phosphogypsum 25%, sodium silicate 25.5%, sodium hydroxide (analytical pure) 12%, and the balance is triethanolamine.

[0052] The rice husk ash is prepared by the following steps: soaking rice husks in hydrochloric acid with a volume fraction of 2.0% for 100 min, with a solid-liquid ratio of 1:50; rinsing with clear water until neutral, then placing in an oven at 53 °C for low-temperature drying for 24 h, then placing in a muffle furnace for calcination at 655 °C for 2.5 h, cooling and then grinding, and passing through a 0.075 mm sieve.

[0053] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activity activator and steel slag micro-powder, and the mass ratio of the steel slag activity activator to the steel slag micro-powder is 10:100.

[0054] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing sodium silicate and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 120 °C for 4 h, and then grinding to D 50 <50 μm; then adding rice husk ash and steel slag micro-powder for dry mixing, and then adding the premixed material and an alcohol amine activator for stirring.

[0055] Example 3

[0056] A steel slag activity activator, the raw materials of which include, by mass percentage: 40% of rice husk ash, 30% of phosphogypsum, 15% of sodium silicate, 12% of sodium hydroxide (analytical pure), 1.8% of triethanolamine, and 1.2% of triisopropanolamine.

[0057] The rice husk ash is prepared by the following steps: submerging rice husks in hydrochloric acid with a volume fraction of 4.0% for 80 min, with a solid-liquid ratio of 1:50; rinsing with clear water until neutral, then placing in an oven at 57 °C for low-temperature drying for 24 h, then placing in a muffle furnace for calcination at 645 °C for 3.5 h, cooling and then grinding, and passing through a 0.075 mm sieve.

[0058] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activity activator and steel slag micro-powder, and the mass ratio of the steel slag activity activator to the steel slag micro-powder is 10:100.

[0059] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing sodium silicate and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 120 °C for 4 h, and then grinding to D 50 <50 μm; then adding rice husk ash and steel slag micro-powder for dry mixing, and then adding the premixed material and alcohol amine-based activator for stirring.

[0060] Example 4

[0061] A steel slag activity activator, the raw materials of which include, by mass percentage: 45% of rice husk ash, 20% of phosphogypsum, 22% of sodium silicate, 11.5% of sodium hydroxide (analytical pure), and the balance is triisopropanolamine.

[0062] The rice husk ash is prepared by the following steps: submerging rice husks in hydrochloric acid with a volume fraction of 3.0% for 90 min, with a solid-liquid ratio of 1:50; rinsing with clear water until neutral, then placing in an oven at 55 °C for low-temperature drying for 24 h, then placing in a muffle furnace for calcination at 650 °C for 3 h, cooling and then grinding, and passing through a 0.075 mm sieve.

[0063] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activity activator and steel slag micro-powder, and the mass ratio of the steel slag activity activator to the steel slag micro-powder is 10:100.

[0064] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing sodium silicate and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 120 °C for 4 h, and then grinding to D 50 <50 μm; then adding rice husk ash and steel slag micro-powder for dry mixing, and then adding the premixed material and alcohol amine-based activator for stirring.

[0065] Comparative Example 1

[0066] A steel slag activity activator, the raw materials of which include, by mass percentage: 88.75% of sodium silicate, 11.25% of sodium hydroxide (analytical pure).

[0067] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activator and steel slag powder, and the mass ratio of the steel slag activator to the steel slag powder is 10:100.

[0068] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing water glass and sodium hydroxide to obtain a premixed material; stirring the steel slag powder and the premixed material.

[0069] Comparative Example 2

[0070] A steel slag activator, the raw materials of which by mass percentage include: 30% of phosphogypsum, 68% of water glass, and 12% of sodium hydroxide (analytical pure).

[0071] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activator and steel slag powder, and the mass ratio of the steel slag activator to the steel slag powder is 10:100.

[0072] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing water glass and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 120°C for 4 h, and then grinding it to D 50 <50 μm; then adding the steel slag powder for dry mixing, and then adding the premixed material and stirring.

[0073] Comparative Example 3

[0074] A steel slag activator, the raw materials of which by mass percentage include: 35% of rice husk ash, 30% of phosphogypsum, 25% of water glass, 10% of sodium hydroxide (analytical pure), and the balance is an alcohol amine activator.

[0075] The rice husk ash is prepared by the following steps: immersing rice husks in an acetic acid aqueous solution with a volume fraction of 1.0% for 1 h, with a solid-liquid ratio of 1:50; rinsing with clean water until neutral, then placing in an oven at 50°C for low-temperature drying for 22 h, then placing in a muffle furnace for calcination at 640°C for 2 h, cooling and then grinding, and passing through a 0.075 mm sieve.

[0076] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activator and steel slag powder, and the mass ratio of the steel slag activator to the steel slag powder is 10:100.

[0077] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: premixing water glass and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 105°C for 4 h, and then grinding it to D 50 <50 μm; then adding the rice husk ash and the steel slag powder for dry mixing, and then adding the premixed material and the alcohol amine activator and stirring.

[0078] The steel slag cementitious materials obtained in Examples 1-4 and Comparative Examples 1-3 were added with water and stirred to the standard consistency of cement, presenting a homogeneous slurry state. Subsequently, referring to GB / T 1346-2024 "Test Methods for Water Requirement of Standard Consistency, Setting Time and Soundness of Cement", the setting times of each group of specimens were measured.

[0079] As Figure 1 shown, the setting times of the specimens obtained in Examples 1-4 and Comparative Examples 2-3 all met the requirements of GB 175-2023 "Common Portland Cement", while the specimen obtained in Comparative Example 1 was difficult to set. Among them, the initial setting time of the homogeneous slurry obtained in Example 4 was the shortest, while the final setting time was longer.

[0080] The steel slag cementitious materials obtained in Examples 1-4 and Comparative Examples 1-3 and cement (P·O42.5) were mixed at mass ratios of 3:7, 4:6, and 5:5 respectively. Then, referring to GB / T 17671-2021 "Test Methods for Strength of Cement Mortar (ISO Method)", the unconfined compressive strength of each group of mortar was tested, and referring to GB / T 20491-2017 "Steel Slag Powder for Cement and Concrete", the activity index of each group of mortar was tested.

[0081] As Figure 2 and Figure 3 shown, the unconfined compressive strengths of the mortar specimens prepared with the steel slag cementitious materials obtained in Examples 1-4 at 7d and 28d were significantly better than those of Comparative Examples 1-3, and the unconfined compressive strength of the mortar specimen prepared with the steel slag cementitious material obtained in Example 4 was the best.

[0082] As Figure 4 and Figure 5 shown, the activity indices of the mortar specimens prepared with the steel slag cementitious materials obtained in Examples 1-4 at 7d and 28d were significantly better than those of Comparative Examples 1-3, and the activity index of the mortar specimen prepared with the steel slag cementitious material obtained in Example 4 was the highest.

[0083] The above results confirm that the effect of the steel slag activity activator obtained in the present invention is significantly better than that of traditional alkaline activators. Using rice husk ash in the present invention can reduce the dosage of water glass and sodium hydroxide, and at the same time can ensure that the activity index of steel slag meets the relevant technical requirements; on this basis, adding a small amount of alkanolamine activators can further stimulate the activity of steel slag, making its activity index reach more than 95%, and the amount of steel slag cementitious material replacing cement can reach 30-50%.

[0084] Example 5

[0085] A steel slag activity activator, the raw materials of which include, by mass percentage: 45% of activated rice husk ash, 20% of phosphogypsum, 22% of water glass, 11.5% of sodium hydroxide (analytical pure), and the balance is triisopropanolamine.

[0086] The activated rice husk ash is prepared by the following steps: Add 150 g of dendritic terminal amino polyamidoamine, 30 g of KH550 coupling agent, and 150 g of OP-10 to 5000 g of water, stir at a speed of 800 r / min for 20 min, add 1500 g of the rice husk ash obtained in Example 4 thereto, perform ultrasonic treatment for 90 min, the ultrasonic frequency is 50 kHz, heat up to 130 °C, perform heat treatment for 10 min, cool down to room temperature, filter, wash, and dry under vacuum.

[0087] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activator and steel slag micropowder, and the mass ratio of the steel slag activator to the steel slag micropowder is 10:100.

[0088] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: Premix water glass and sodium hydroxide to obtain a premixed material; dehydrate phosphogypsum at 120 °C for 4 h, and then grind it to D 50 <50 μm; then add activated rice husk ash and steel slag micropowder for dry mixing, and then add the premixed material and an alcohol amine activator and stir.

[0089] Comparative Example 4

[0090] A steel slag activator, the raw materials of which include, by mass percentage: 45% of activated rice husk ash, 20% of phosphogypsum, 22% of water glass, 11.5% of sodium hydroxide (analytical pure), and the balance is triisopropanolamine.

[0091] The activated rice husk ash is prepared by the following steps: Mix 150 g of dendritic terminal amino polyamidoamine, 30 g of KH550 coupling agent, and 1500 g of the rice husk ash obtained in Example 4 evenly.

[0092] A steel slag cementitious material, the raw materials of which include: the above-mentioned steel slag activator and steel slag micropowder, and the mass ratio of the steel slag activator to the steel slag micropowder is 10:100.

[0093] The preparation method of the above-mentioned steel slag cementitious material includes the following steps: Premix water glass and sodium hydroxide to obtain a premixed material; dehydrate phosphogypsum at 120 °C for 4 h, and then grind it to D 50 <50 μm; then add activated rice husk ash and steel slag micropowder for dry mixing, and then add the premixed material and an alcohol amine activator and stir.

[0094] Add water to the steel slag cementitious materials obtained in Example 5 and Comparative Example 4 and stir until the standard consistency of cement is reached, presenting a homogeneous slurry state, and then refer to GB / T 1346-2024 "Test Methods for Water Requirement for Standard Consistency, Setting Time and Soundness of Cement" to determine the setting time of each group of specimens.

[0095] As Figure 6As shown, the setting times of the specimens obtained in Example 4, Example 5, and Comparative Example 4 all meet the requirements of GB 175-2023 "Common Portland Cement".

[0096] The steel slag cementitious materials obtained in Example 5 and Comparative Example 4 and cement (P·O 42.5) were mixed at mass ratios of 3:7, 4:6, and 5:5 respectively, and then the unconfined compressive strengths of the mortar specimens in each group were tested with reference to GB / T 17671-2021 "Methods of test for strength of hydraulic cement mortar (ISO method)", and the activity indices of the mortar specimens in each group were tested with reference to GB / T 20491-2017 "Steel slag powder used for cement and concrete".

[0097] As Figure 7 and Figure 8 shown, the 7-day and 28-day unconfined compressive strengths of the mortar specimens prepared with the steel slag cementitious material obtained in Example 5 are significantly better than those in Example 4 and Comparative Example 4. As Figure 9 and Figure 10 shown, the 7-day and 28-day activity indices of the mortar specimens prepared with the steel slag cementitious material obtained in Example 5 are better than those in Example 4 and Comparative Example 4.

[0098] As mentioned above, the above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, according to the technical solution and inventive concept of the present invention, making equivalent substitutions or changes, shall be covered by the protection scope of the present invention.

Claims

1. An activator for steel slag activity, characterized in that, Its raw materials by mass percentage include: rice husk ash or activated rice husk ash 35-45%, phosphogypsum 20-30%, water glass 15-25.5%, sodium hydroxide 9-12%, and the balance is alkanolamine activator.

2. The activator for activating the activity of steel slag according to claim 1, wherein The alkanolamine activator is triethanolamine, N-methyldiethanolamine or / and triisopropanolamine.

3. The activator for activating the activity of steel slag according to claim 1, wherein The rice husk ash is prepared by the following steps: Immerse the rice husks in an acidic solution for 1-2 h; rinse with clear water until neutral, then dry at a low temperature of 50-60 °C for 22-26 h, calcine at 650 ± 10 °C for 2-4 h, and grind and sieve after cooling.

4. The activator for activating the activity of steel slag according to claim 3, characterized in that, The acidic solution is acetic acid aqueous solution or hydrochloric acid, the volume fraction of the acidic solution is 1.0-5.0%, and the mass ratio of rice husks to the acidic solution is 1:48-52.

5. The activator for activating the activity of steel slag according to claim 1, wherein The activated rice husk ash is prepared by the following steps: Add dendritic amino-terminated polyamide-amine, silane coupling agent, and dodecyl polyoxyethylene ether to water and stir for 10-30 min, add rice husk ash thereto and perform ultrasonic treatment for 1-2 h, heat up to 120-140 °C and perform heat treatment for 5-15 min, cool to room temperature, filter, wash, and dry under vacuum.

6. The activator for activating the activity of steel slag according to claim 5, wherein The mass ratio of dendritic amino-terminated polyamide-amine, silane coupling agent, dodecyl polyoxyethylene ether, and rice husk ash is 1-2:1-2:1-2:10-20.

7. Application of the steel slag activity activator according to any one of claims 1-6 in the preparation of steel slag cementitious materials.

8. A steel slag cementitious material, characterized in that, Its raw materials include: the steel slag activity activator according to any one of claims 1-6 and steel slag powder, and the mass ratio of the steel slag activity activator to the steel slag powder is 8-16:

100.

9. The steel slag cementitious material according to claim 8, wherein The particle size of steel slag powder is ≤ 0.5 mm, and the specific surface area is ≥ 400 m 2 / kg.

10. A preparation method of the steel slag cementitious material as described in claim 8, characterized in that, It includes the following steps: premixing sodium silicate and sodium hydroxide to obtain a premixed material; dehydrating phosphogypsum at 105 - 170 °C for 4 - 5 h, and then grinding it to D 50 <50 μm; then adding rice husk ash or activated rice husk ash and steel slag micropowder for dry mixing, and then adding the premixed material and an alcohol amine activator for stirring.

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