A waste-utilizing low-carbon cementitious material and a preparation and use method thereof

Abstract

The application belongs to the technical field of reusing industrial solid wastes, and discloses a waste-reusing low-carbon cementing material and a preparation and use method thereof. The cementing material comprises the following components in mass fraction: 40-97 parts of steel slag, 0-50 parts of mineral slag, 0-10 parts of alkali slag, 0-6 parts of lithium slag, 3-15 parts of a solid reinforcing agent, and 0-0.2 parts of a liquid modifier. The solid reinforcing agent comprises the following components in mass fraction: 0-30 parts of carbide slag, 0-30 parts of sodium carbonate, and 10-80 parts of layer silicon. The liquid modifier comprises the following components in mass fraction: 5-20 parts of acrylamide, 5-20 parts of N-methyl diethanolamine, and 60-90 parts of water. The cementing material has relatively optimal hydration and hardening performance, and improves the resource utilization of steel slag.

Description

Technical Field

[0001] The present application relates to the technical field of industrial solid waste recycling, and in particular to a waste-recycling and low-carbon cementitious material and a preparation and use method thereof. Background Art

[0002] Steel slag is a solid waste generated during the steelmaking process, and its mineral composition is similar to that of cement clinker. The hydration of the hydraulic components in steel slag can produce hydrated calcium silicate, hydrated calcium aluminate gel, calcium hydroxide, etc. Therefore, steel slag has the potential to be used as an auxiliary cementitious material in building materials to replace cement, thereby reducing the use of cement and the high energy consumption and high carbon emissions associated with cement-based cementitious materials, thereby achieving the benefits of energy conservation, environmental protection, waste utilization and emission reduction. However, due to the low content of active minerals and hydration activity in steel slag, the mechanical properties of steel slag after hydration and hardening are far lower than those of cement, which also limits the resource utilization efficiency of steel slag as a cementitious material.

[0003] To address the low gelling activity of steel slag, physical and chemical methods are often used to stimulate or enhance its gelling properties. Mechanical grinding stimulates the gelling activity of steel slag by applying strong physical forces, which continuously reduces the size of slag particles while simultaneously disrupting the slag crystal structure and altering its surface physical and chemical properties. Chemical stimulation primarily involves the addition of chemical admixtures to accelerate the dissolution of active minerals in the slag and the precipitation of the resulting gelling products, thereby improving the hydration and hardening properties of the slag.

[0004] However, due to the poor grindability of steel slag, its refinement requires considerable grinding energy. Furthermore, during the refinement process, fine particles tend to adhere to each other, causing particle agglomeration and significantly reducing the grinding efficiency. Furthermore, chemical excitation of steel slag currently relies primarily on cement concrete admixtures, which have limited and often unsatisfactory effects on steel slag. Therefore, there is an urgent need to overcome the bottleneck of low cementitious activity of existing steel slag and seek efficient methods for its resource utilization in building materials. Summary of the Invention

[0005] To this end, the embodiments of the present application provide a waste-recycling and low-carbon cementitious material, which improves the hydration and hardening properties of the cementitious material and improves the resource utilization of steel slag.

[0006] In a first aspect, the present application provides a waste-recycling and low-carbon cementitious material.

[0007] This application is achieved through the following technical solutions:

[0008] The gelling material comprises:

[0009] The following components in parts by weight: 40-97 parts of steel slag, 0-50 parts of mineral slag, 0-10 parts of alkali slag, 0-6 parts of lithium slag, 3-15 parts of solid reinforcing agent, and 0-0.2 parts of liquid modifier;

[0010] The solid reinforcing agent comprises the following components in parts by mass: 0 to 30 parts of carbide slag, 0 to 30 parts of sodium carbonate and 10 to 80 parts of layered silicon;

[0011] The liquid modifier comprises the following components in parts by mass: 5 to 20 parts of acrylamide, 5 to 20 parts of N-methyldiethanolamine and 60 to 90 parts of water.

[0012] In a preferred example of the present application, it can be further configured that the steel slag is selected from at least one of converter slag, electric furnace slag or ladle furnace slag discharged when the steel industry uses converters, electric furnaces or ladle furnaces to smelt steel;

[0013] The steel slag contains C2S, C3A, C 12 A7, C3S, CaO and / or MgO minerals.

[0014] In a preferred example of the present application, it can be further configured that the slag is selected from granulated blast furnace slag, the granulated blast furnace slag contains active amorphous glass ore body, and the amorphous glass ore body includes at least one of Al2O3 or SiO2.

[0015] In a preferred example of the present application, it can be further configured that the alkali slag is selected from the waste slag discharged during the preparation of soda ash in the ammonia-soda industry, and the particle size of the alkali slag is 10 to 25 μm; the alkali slag contains CaO, CaCO3, CaSO4, CaCl2 and SiO2; wherein the CaO content in the alkali slag is greater than 50%.

[0016] In a preferred example of the present application, it can be further configured that the lithium slag is selected from the waste slag generated in the process of producing lithium carbonate by the spodumene sulfuric acid method, and the particle size of the lithium slag is 20 to 45 μm; the lithium slag contains active SiO2, Al2O3, SO3 and CaO, wherein the content of SiO2 is greater than 50%, the content of Al2O3 is 10% to 20%, the content of SO3 is 5% to 15%, and the content of CaO is 5% to 20%.

[0017] In a preferred example of the present application, it can be further configured that the carbide slag is waste residue produced when carbide is hydrolyzed to prepare acetylene, and the main component of the carbide slag is Ca(OH)2.

[0018] In a preferred example of the present application, it can be further configured that the layer silicon in the solid reinforcing agent is layered crystalline sodium disilicate, including at least one of the δ-type, β-type, α-type, and γ-type crystal forms.

[0019] In a second aspect, the present application provides a method for preparing a waste-recycling and low-carbon cementitious material.

[0020] This application is achieved through the following technical solutions:

[0021] A method for preparing a waste-recycling and low-carbon cementitious material, comprising:

[0022] Step 1: Mix acrylamide, N-methyldiethanolamine and water in a predetermined ratio and stir until completely dissolved to prepare a liquid modifier;

[0023] Step 2: Steel slag, slag, alkali slag, and lithium slag are mixed in a preset proportion to form a mixed solid waste powder, and the liquid modifier prepared in step 1 is evenly sprayed on the surface of the mixed solid waste powder by dropwise addition or by spraying after dilution by 2-3 times, and then the mixed solid waste powder with the liquid modifier added is transferred to a ball mill for grinding to form an active solid waste powder;

[0024] Step 3: Evenly mix carbide slag, sodium carbonate and layer silicon according to a preset ratio to prepare a solid reinforcing agent;

[0025] Step 4: using the active solid waste powder obtained in step 2 as the first component of the cementitious material, and using the solid reinforcing agent obtained in step 3 as the second component of the cementitious material.

[0026] In a third aspect, the present application provides a method for using a waste-recycling and low-carbon cementitious material.

[0027] This application is achieved through the following technical solutions:

[0028] A method for using a waste-recycling low-carbon cementitious material, wherein the cementitious material is the cementitious material described in the first aspect or the cementitious material prepared by the preparation method of the second aspect. The method for using the cementitious material is as follows: a first component of the low-carbon cementitious material and a second component of the low-carbon cementitious material are uniformly mixed in a preset proportion to form a mixture, and then water and aggregate are added and stirred to prepare a low-carbon hardened material; the hardened material is used in at least one scenario of mine filling, foundation treatment, soft soil solidification, and building mortar.

[0029] In a preferred example of the present application, it can be further configured as follows: the second component of the low-carbon cementitious material is added to water, stirred evenly, and then the first component is added according to a preset ratio, and the aggregate is added and stirred evenly to prepare a low-carbon hardened material.

[0030] In summary, compared with the prior art, the technical solutions provided by the embodiments of the present application provide at least the following beneficial effects: 40 to 97 parts of steel slag, 0 to 50 parts of slag, 0 to 10 parts of alkali slag, 0 to 6 parts of lithium slag, 3 to 15 parts of solid reinforcing agent, and 0 to 0.2 parts of liquid modifier are used to prepare the cementitious material; wherein the solid reinforcing agent includes 0 to 30 parts of carbide slag, 0 to 30 parts of sodium carbonate, and 10 to 80 parts of silica; and the liquid modifier includes 5 to 20 parts of acrylamide, 5 to 20 parts of N-methyldiethanolamine, and 60 to 90 parts of water. The cementitious material in the present application utilizes steel slag to the greatest extent, supplemented by a small amount of slag, alkali slag, lithium slag, and admixtures, effectively solving the problem of industrial solid waste accumulation and realizing the efficient resource utilization of steel slag.

[0031] The liquid modifier, composed of acrylamide, N-methyldiethanolamine, and water, has a positive effect on the preparation and performance improvement of waste-recycling cementitious materials. The liquid modifier components have strong molecular polarity, and functional groups such as hydroxyl and amine groups can be adsorbed on the surface of particles such as steel slag, mineral slag, alkaline slag, and lithium slag, effectively eliminating particle agglomeration of steel slag and other substrates during grinding and improving grinding efficiency. The amine groups in the liquid modifier components have a complexing / chelating effect on calcium ions, acting as a solubilizing and activating agent for steel slag, promoting the dissolution of silicate minerals in the steel slag during hydration, accelerating the hydration of the steel slag cementitious materials, and improving their hardening properties. The acrylamide component in the liquid modifier undergoes a self-polymerization reaction under alkaline conditions in the cementitious materials to generate a water-soluble polyacrylamide polymer, which can chemically react with calcium and aluminum ions in the steel slag cementitious system to form a stable network structure, thereby improving the hardening properties of the steel slag cementitious materials.

[0032] Solid reinforcing agent can effectively stimulate the activity of steel slag in multiple ways. Among them, the layered silicon in the reinforcing agent has excellent ion exchange capacity for the steel slag gel system due to its unique layered structure, alkaline effect and pH buffering capacity. + Exchange with metal ions in steel slag minerals, acting as an ion transporter (mainly Ca 2+ 、Al 3+ and Mg 2+) and improves the pH value of the pore solution to promote the dissolution of steel slag particles (mainly C2S, C2F and calcium ferrite) and the formation of two types of gel hydration products: a silica gel containing calcium and aluminum with a high degree of polymerization, and a C-(A)-SH gel, thereby significantly improving the hydration and hardening properties of the steel slag. (b) The alkalinity of the carbide slag and sodium carbonate in the reinforcing agent also stimulates the steel slag, promoting its activity and hydration reaction. In particular, the double decomposition reaction between the two to form NaOH can provide an alkaline environment for the system, promoting the self-polymerization reaction of acrylamide in the liquid modifier to form polyacrylamide. On the other hand, the alkaline environment provided by the two is also conducive to the ion exchange of the layered silicon, promoting the dissolution-precipitation reaction of the steel slag, and improving the hydration and hardening properties of the steel slag cementitious material.

[0033] The carbide slag and sodium carbonate in the solid reinforcer of the present application will react to form a NaOH alkaline system during the mixing and hydration process of the cementitious material, avoiding the traditional method of directly adding strong alkali NaOH, which may cause harm to production and construction workers, and reducing the impact and even pollution of industrial NaOH preparation on the environment. It is safe and efficient, and helps to reuse solid wastes such as carbide slag, which is waste-saving and environmentally friendly.

[0034] The preferred method of use provided by the present application is also unique. After the second component is added to the mixing water, the carbide slag and sodium carbonate are reacted to form NaOH to provide an alkaline environment for the system, and then the first component is added. On the one hand, it is beneficial for the acrylamide in the first component to undergo polymerization in an alkaline environment to generate water-soluble polyacrylamide polymers, thereby improving the hydration products of the steel slag gel system. On the other hand, the sufficiently uniform alkaline environment is beneficial to accelerate the dissolution-precipitation reaction of the steel slag gel minerals. This step-by-step method of use (or step-by-step, gradient activation idea) avoids the traditional method of adding all the powders together to the mixing water, in which the steel slag particles absorb most of the water, resulting in the inability of the carbide slag and sodium carbonate to fully dissolve and react to generate sodium hydroxide, which in turn fails to provide a higher alkalinity for the system, thereby further affecting the polymerization reaction of acrylamide.

[0035] The present invention has a wide range of applications, especially as a fully solid waste cementitious material, and can be widely used in mine filling, foundation treatment, soft soil solidification, roadbed and pavement, construction mortar and other fields. In addition, it can also be used as an auxiliary cementitious material to replace traditional mineral admixtures in cement concrete. DETAILED DESCRIPTION

[0036] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

[0037] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0038] In addition, the term "and / or" in this application is simply a description of the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application, unless otherwise specified, generally indicates that the related objects are in an "or" relationship.

[0039] In this application, the terms "first", "second", etc. are used to distinguish identical or similar items with substantially the same effects and functions. It should be understood that there is no logical or temporal dependency between "first", "second", and "nth", nor is there any limitation on the quantity and execution order.

[0040] The waste-recycling and low-carbon gelling material, preparation method and use method provided by the present application are described in detail below.

[0041] The present application provides a waste-recycling, low-carbon cementitious material. The cementitious material comprises the following components by weight: 40-97 parts steel slag, 0-50 parts slag, 0-10 parts alkaline slag, 0-6 parts lithium slag, 3-15 parts solid reinforcing agent, and 0-0.2 parts liquid modifier. The solid reinforcing agent comprises the following components by weight: 0-30 parts carbide slag, 0-30 parts sodium carbonate, and 10-80 parts silica; the liquid modifier comprises the following components by weight: 5-20 parts acrylamide, 5-20 parts N-methyldiethanolamine, and 60-90 parts water. This application uses steel slag as a base material, supplemented with slag, alkaline slag, and lithium slag, and combines the solid reinforcing agent and liquid modifier to effectively enhance the activity of the cementitious material. By controlling the mass fractions of each component within the aforementioned conditions, the layered silicon in the solid reinforcing agent plays a better exchange role with the steel slag cementitious material, promoting the dissolution of steel slag ions and its hydration reaction. At the same time, at this component ratio, calcium carbide slag and sodium carbonate will also react to generate NaOH, providing an alkaline environment for the system, which can also stimulate the steel slag and promote its activity and hydration reaction. The mass fraction of steel slag can reach up to 97 parts, maximizing its utilization. Its widespread application can effectively solve the problem of the accumulation of difficult-to-treat industrial solid waste such as steel slag, and achieve efficient utilization of building materials such as steel slag.

[0042] The layered silicon in the solid reinforcing agent has a unique layered structure, alkaline effect and pH buffering capacity. Specifically, layered silicon (Na2Si2O5) is a layered crystalline sodium disilicate, including at least one of the δ-type, β-type, α-type and γ-type crystal forms. Layered silicon has excellent ion exchange capacity for the steel slag gel system, through the Na + It can exchange with metal ions in steel slag minerals and act as an ion transporter, mainly targeting Ca 2+ 、Al 3+ and Mg 2+ ions, and can improve the pH value of the pore solution to promote the dissolution of steel slag particles, mainly promoting the dissolution of C2S, C2F and calcium iron ore, and promoting the formation of two types of gel hydration products, one is a silica gel containing calcium and aluminum with a high degree of polymerization, and the other is C-(A)-SH gel, thereby significantly improving the hydration and hardening properties of steel slag. The carbide slag is the waste residue produced when calcium carbide (CaC2) is hydrolyzed to produce acetylene (C2H2), and its main component is calcium hydroxide Ca(OH)2. The alkalinity of carbide slag and sodium carbonate can activate steel slag and promote the activity and hydration reaction of steel slag. In particular, the sodium hydroxide NaOH produced by the double decomposition reaction of carbide slag and sodium carbonate can provide an alkaline environment for the system, promoting the self-polymerization reaction of acrylamide in the liquid modifier to form polyacrylamide; on the other hand, the alkaline environment provided by carbide slag and sodium carbonate can promote the ion exchange of layered silicon, promote the dissolution-precipitation reaction of steel slag, and improve the hydration and hardening properties of steel slag gel materials. At the same time, the use of carbide slag and sodium carbonate to form a sodium hydroxide NaOH environment can avoid the traditional operation of directly adding strong alkali, which may harm production and construction workers, and reduce the impact of industrial NaOH preparation on the environment and even pollution. It is safe and efficient, and also realizes the reuse of solid waste such as carbide slag, which is more environmentally friendly.

[0043] The liquid modifier is composed of acrylamide (C3H5NO), N-methyldiethanolamine (C5H 13 The liquid modifier is composed of a mixture of nitric oxide (NO2) and water (H2O), and each component has a strong molecular polarity. In particular, functional groups such as hydroxyl and amine groups can be adsorbed on the surface of particles such as steel slag, mineral slag, alkaline slag and lithium slag, which can effectively eliminate the agglomeration of particles of substrates such as steel slag during the powder preparation process, thereby improving the powder preparation efficiency. The amine group in the liquid modifier has a complexing / chelating effect on calcium ions, which can solubilize and activate the steel slag, that is, it can accelerate the dissolution of silicate minerals in the steel slag during the hydration process, accelerate the hydration of the steel slag cementitious material, and improve its hardening performance. At the same time, the acrylamide component in the liquid modifier will undergo a self-polymerization reaction under the alkaline conditions of the cementitious material to generate a water-soluble polyacrylamide polymer. The polyacrylamide polymer can chemically react with the calcium ions and aluminum ions in the steel slag cementitious system to form a stable network structure, thereby improving the hardening performance of the cementitious material.

[0044] This waste-recycling, low-carbon cementitious material can be used as a fully solid waste cementitious material and can be widely used in mine filling, foundation treatment, soft soil solidification, foundation pavement, and construction mortar. In addition, it can also be used as an auxiliary cementitious material in cement concrete instead of traditional mineral admixtures.

[0045] The present application provides a method for preparing a waste-recycling low-carbon gelling material, the method comprising:

[0046] Step 1: Mix acrylamide, N-methyldiethanolamine and water in a predetermined ratio and stir until completely dissolved to prepare a liquid modifier;

[0047] Step 2: Steel slag, slag, alkali slag and lithium slag are mixed in a preset ratio to prepare a mixed solid waste powder, and the liquid modifier prepared in step 1 is evenly sprayed on the surface of the mixed solid waste powder by dropwise addition or by spraying after dilution by 2-3 times, and then the mixed solid waste powder with the liquid modifier added is transferred to a ball mill for grinding until the specific surface area of ​​the mixed solid waste powder reaches 440m 2 / kg or more, and made into active solid waste powder;

[0048] Step 3: Evenly mix carbide slag, sodium carbonate and layer silicon according to a preset ratio to prepare a solid reinforcing agent;

[0049] Step 4: The active solid waste powder obtained in step 2 is used as the first component of the low-carbon cementitious material, and the solid reinforcing agent obtained in step 3 is used as the second component of the low-carbon cementitious material, thereby obtaining a waste-recycling low-carbon cementitious material.

[0050] The present application also provides a method for using a waste-recycling low-carbon cementitious material. When in use, the first component of the low-carbon cementitious material and the second component of the low-carbon cementitious material are mixed evenly according to a preset proportion to form a mixture, and then water and aggregate are added and stirred to prepare a low-carbon hardened material.

[0051] Preferably, the second component of the low-carbon cementitious material is added to the mixing water and stirred evenly. The first component is then added according to a preset ratio, and the aggregate is added and stirred evenly to prepare the low-carbon hardened material. After the second component, the solid reinforcing agent, is added to the mixing water, the carbide slag in the solid reinforcing agent reacts with the sodium carbonate in the mixing water to produce NaOH, providing an alkaline environment for the system. The first component, a mixture of steel slag, slag, alkaline slag, lithium slag, and a liquid modifier, is then added. This facilitates the polymerization of acrylamide in the liquid modifier under the alkaline environment, producing water-soluble polyacrylamide polymers and improving the hydration products of the steel slag cementitious system. Furthermore, the fully uniform alkaline environment helps accelerate the dissolution-precipitation reaction of the steel slag cementitious minerals. This distributed progressive application method avoids the traditional method of adding all the powders to the mixing water at once. Because the steel slag particles absorb most of the water, the carbide slag and sodium carbonate cannot fully dissolve and react to form sodium hydroxide, resulting in a failure to provide a higher alkalinity for the system, further affecting the polymerization reaction of the acrylamide.

[0052] The present invention will be further described below with reference to the following examples, but the present invention can be implemented in many different ways as defined and covered by the claims.

[0053] Example 1

[0054] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is added dropwise to the above-mentioned mixed solid waste powder, and the powder is continuously ground to prepare an active solid waste powder; 3 parts of layered silicon are taken as a solid reinforcing agent, and the solid reinforcing agent is mixed with the above-mentioned active solid waste powder to prepare a gelling material.

[0055] Example 2:

[0056] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is added dropwise to the above-mentioned mixed solid waste powder, and the powder is continuously ground to prepare an active solid waste powder; 5 parts of layered silicon are taken as a solid reinforcing agent, and the solid reinforcing agent is mixed with the above-mentioned active solid waste powder to prepare a gelling material.

[0057] Example 3

[0058] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is added dropwise to the above-mentioned mixed solid waste powder, and the powder is continuously ground to prepare an active solid waste powder; 10 parts of layered silicon are taken as a solid reinforcing agent, and the solid reinforcing agent is mixed with the above-mentioned active solid waste powder to prepare a gelling material.

[0059] Example 4

[0060] Mix 5 parts of acrylamide, 10 parts of N-methyldiethanolamine and 85 parts of water to form a liquid modifier; place 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag in a ball mill and mix them evenly to form a mixed solid waste powder; add 0.05 parts of the liquid modifier dropwise to the above mixed solid waste powder and continue grinding to form an active solid waste powder; take 10 parts of carbide slag, 10 parts of sodium carbonate and 80 parts of layered silicon and mix them evenly in proportion to form a solid enhancer; take 5 parts of the solid enhancer and mix it with the above active solid waste powder to form a gelling material.

[0061] Example 5

[0062] Preparation of cementitious materials:

[0063] 15 parts of acrylamide, 15 parts of N-methyldiethanolamine and 70 parts of water are mixed evenly to prepare a liquid modifier; 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.02 parts of liquid modifier are dropped onto the above mixed solid waste powder and continue to grind to prepare active solid waste powder; 25 parts of carbide slag, 15 parts of sodium carbonate and 60 parts of layered silicon are mixed evenly in proportion to prepare a solid enhancer, 5 parts of solid enhancer are taken and mixed with the above active solid waste powder to prepare a gelling material.

[0064] Example 6

[0065] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder and continued to be ground to prepare an active solid waste powder; 3 parts of layered silicon are taken as a solid reinforcing agent and mixed with the above-mentioned active solid waste powder to prepare a waste-saving and low-carbon cementitious material.

[0066] Example 7

[0067] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder and continued to be ground to prepare an active solid waste powder; 3 parts of layered silicon are taken as a solid reinforcing agent and mixed with the above-mentioned active solid waste powder to prepare a waste-saving and low-carbon cementitious material.

[0068] Example 8

[0069] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder and continued to be ground to prepare an active solid waste powder; 10 parts of layered silicon are taken as a solid reinforcing agent and mixed with the above-mentioned active solid waste powder to prepare a waste-saving and low-carbon cementitious material.

[0070] Example 9

[0071] 10 parts of acrylamide, 15 parts of N-methyldiethanolamine and 75 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.03 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder and continued to be ground to prepare an active solid waste powder; 20 parts of calcium carbide slag and 30 parts of sodium carbonate are mixed evenly to prepare a solid reinforcer; the active solid waste powder and the solid reinforcer are respectively packaged as the first component and the second component of the cementitious material, and used in a ratio of first component:second component = 95:5, thereby preparing a waste-saving and low-carbon cementitious material.

[0072] Example 10

[0073] 5 parts of acrylamide, 10 parts of N-methyldiethanolamine and 85 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag, 2 parts of alkali slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.05 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder, and the powder is continuously ground to prepare an active solid waste powder; 10 parts of calcium carbide slag, 10 parts of sodium carbonate and 80 parts of layered silicon are mixed evenly to prepare a solid reinforcing agent; the active solid waste powder and the solid reinforcing agent are respectively packaged as the first component and the second component of the cementitious material, and used in a ratio of first component:second component = 95:5, thereby preparing a waste-saving and low-carbon cementitious material.

[0074] Example 11

[0075] 15 parts of acrylamide, 15 parts of N-methyldiethanolamine and 70 parts of water are mixed evenly to prepare a liquid modifier; 45 parts of steel slag, 50 parts of slag and 3 parts of lithium slag are placed in a ball mill and mixed evenly to prepare a mixed solid waste powder; 0.02 parts of the liquid modifier is dropped onto the above-mentioned mixed solid waste powder and continued to be ground to prepare an active solid waste powder; 25 parts of carbide slag, 15 parts of sodium carbonate and 60 parts of layered silicon are mixed evenly to prepare a solid reinforcing agent; the active solid waste powder and the solid reinforcing agent are respectively packaged as the first component and the second component of the cementitious material, and used in a ratio of first component:second component = 95:5, thereby preparing a waste-saving and low-carbon cementitious material.

[0076] Comparative Example 1

[0077] 95 parts of steel slag, 2 parts of alkali slag and 3 parts of lithium slag were placed in a ball mill and mixed evenly to make mixed solid waste powder as a cementitious material.

[0078] Comparative Example 2

[0079] 45 parts of steel slag, 50 parts of ore slag, 2 parts of alkali slag and 3 parts of lithium slag were placed in a ball mill and mixed evenly to make a mixed solid waste powder as a cementitious material.

[0080] Examples 1 to 11 and Comparative Examples 1 to 2 were all subjected to slurry molding experiments according to a ratio of water: cementitious material = 0.35:1. In the molding experiments of Examples 1 to 8, the active solid waste powder and the solid reinforcing agent were mixed evenly, and water and aggregate were added and stirred to prepare a hardened material; in the molding experiments of Examples 9 to 11, the active solid waste powder was added to the mixing water and stirred evenly, and then the solid reinforcing agent was added and stirred evenly before pouring and molding.

[0081] Performance testing:

[0082] The molded test blocks of Examples 1-11 and Comparative Examples 1-2 were cured under standard curing conditions of 20±1°C and humidity above 90% for 7 and 28 days, respectively. The strength of the test blocks was then tested using a press in accordance with GBT17671. The strength test results for Examples 1-11 and Comparative Examples 1-2 are shown in Table 1 below:

[0083] Table 1

[0084]

[0085]

[0086] As can be seen from Table 1, the early and late strengths of the carbon cementitious materials of Examples 1-5 (excluding slag) of this application are significantly higher than those of the slag-free Comparative Example 1. Their 7-day strength increases from 0 MPa in Comparative Example 1 to 7.5-12.8 MPa, and their 28-day strength increases from 6.7 MPa in Comparative Example 1 to 15.4-22.3 MPa, demonstrating excellent performance. Furthermore, the amount of steel slag used is essentially over 90%, significantly reducing waste and improving environmental protection. The early and late strengths of the cementitious materials of Examples 6-11 are also significantly higher than those of the corresponding Comparative Example 2. Their 7-day strength increases from 9.2 MPa in Comparative Example 2 to 14.8-37.2 MPa, and their 28-day strength increases from 19.6 MPa in the control group to 26.1-51.2 MPa, demonstrating excellent mechanical properties. The early and late strengths of the waste-recycling low-carbon cementitious materials of Examples 9-11, which utilize a step-by-step addition method, are also far higher than those of Comparative Example 2, with the early strength even exceeding that of Example 7, demonstrating excellent performance. In addition, from the comparison between the above examples and the comparative examples, it can be seen that the liquid modifier and the solid reinforcing agent in the present invention have a significant promoting effect on the development of the hydration and hardening properties of the cementitious material.

[0087] Those skilled in the art will clearly understand that the above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification, equivalent change and modification of the above embodiment made according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. A waste-recycling and low-carbon cementitious material, characterized in that: The gelling material comprises: The following components by mass: 40-97 parts of steel slag, 0-50 parts of slag, 2-10 parts of alkali slag, 3-6 parts of lithium slag, 3-15 parts of solid reinforcing agent, 0.02-0.2 parts of liquid modifier, wherein the steel slag contains C2S, C3A, C 12 A7, C3S, CaO and / or MgO minerals, the slag contains active amorphous glass ore bodies, the amorphous glass ore bodies include at least one of Al2O3 or SiO2, the alkali slag contains CaO, CaCO3, CaSO4, CaCl2 and SiO2, and the lithium slag contains active SiO2, Al2O3, SO3 and CaO; The solid reinforcing agent comprises the following components in parts by weight: 0 to 30 parts of carbide slag, 0 to 30 parts of sodium carbonate, and 10 to 80 parts of layered silicon. The layered silicon in the solid reinforcing agent is layered crystalline sodium disilicate, including at least one of the δ-type, β-type, α-type, and γ-type crystal forms. The liquid modifier comprises the following components in parts by mass: 5 to 20 parts of acrylamide, 5 to 20 parts of N-methyldiethanolamine and 60 to 90 parts of water.

2. The waste-recycling low-carbon cementitious material according to claim 1, characterized in that: The steel slag is selected from at least one of converter slag, electric furnace slag or ladle furnace slag discharged when the steel industry uses converters, electric furnaces or ladle furnaces to smelt steel.

3. The waste-recycling low-carbon cementitious material according to claim 1, characterized in that: The slag is selected from granulated blast furnace slag.

4. The waste-recycling low-carbon cementitious material according to claim 1, characterized in that: The alkali residue is selected from waste residue discharged during the process of preparing soda ash in the ammonia-alkali industry. The particle size of the alkali residue is 10-25 μm, and the CaO content in the alkali residue is greater than 50%.

5. The waste-recycling low-carbon cementitious material according to claim 1, characterized in that: The lithium slag is selected from the waste slag generated in the process of producing lithium carbonate by the spodumene sulfuric acid method, and the particle size of the lithium slag is 20 to 45 μm; the SiO2 content is greater than 50%, the Al2O3 content is 10% to 20%, the SO3 content is 5% to 15%, and the CaO content is 5% to 20%.

6. The waste-recycling low-carbon cementitious material according to claim 1, characterized in that: The carbide slag is waste residue generated when carbide is hydrolyzed to prepare acetylene, and the main component of the carbide slag is Ca(OH)2.

7. A method for preparing a waste-recycling low-carbon cementitious material, characterized in that: The preparation method comprises: Step 1: Mix 5 to 20 parts of acrylamide, 5 to 20 parts of N-methyldiethanolamine, and 60 to 90 parts of water by weight, and stir until completely dissolved to prepare a liquid modifier; Step 2: According to the weight ratio of 40 to 97 parts of steel slag, 0 to 50 parts of slag, 2 to 10 parts of alkali slag, and 3 to 6 parts of lithium slag, steel slag, slag, alkali slag, and lithium slag are mixed to form a mixed solid waste powder, and 0.02 to 0.2 parts of the liquid modifier prepared in step 1 are evenly sprayed on the surface of the mixed solid waste powder by dropwise addition or by spraying after being diluted 2 to 3 times, and then the mixed solid waste powder with the liquid modifier added is transferred to a ball mill for grinding to form an active solid waste powder; Step 3: According to the weight ratio of 0 to 30 parts of carbide slag, 0 to 30 parts of sodium carbonate and 10 to 80 parts of layer silicon, the carbide slag, sodium carbonate and layer silicon are mixed evenly to prepare a solid reinforcing agent; Step 4: The active solid waste powder obtained in step 2 is used as the first component of the cementitious material, and 3 to 15 parts by mass of the solid reinforcing agent obtained in step 3 is used as the second component of the cementitious material.

8. A method for using waste-recycling low-carbon cementitious materials, characterized in that: The cementitious material is a cementitious material prepared by the preparation method according to claim 7, and the method for using the cementitious material is: mixing the first component of the cementitious material and the second component of the cementitious material in a preset proportion to form a mixture, and then adding water and aggregate and stirring to prepare a hardened material; The hardening material is used in at least one scenario of mine filling, foundation treatment, soft soil solidification, and construction mortar.

9. The method for using the waste-recycling low-carbon cementitious material according to claim 8, characterized in that: The second component of the cementitious material is added to water and stirred evenly, and then the first component of the cementitious material is added according to a preset ratio, and the aggregate is added and stirred evenly to prepare a hardened material.

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