Formula and preparation method of geopolymer loess curing agent based on multiple bulk solid wastes

Abstract

The invention discloses a geopolymer loess curing agent formula based on multi-element bulk solid waste and a preparation method thereof, and relates to the technical field of bulk solid waste geopolymer loess curing agents, the geopolymer loess curing agent formula comprises the following components: 50-70 parts of a curing material component, 10-30 parts of a reinforcing component, and 5-25 parts of an excitation component; the curing material component is fly ash, and the particle size of the curing material component is smaller than 300 microns; the reinforcing component is rice hull ash (the main component is SiO2); the single-component geopolymer curing agent is prepared by taking the rice hull ash and bulk solid waste as main raw materials, the use amount of solid waste exceeds 80%, on one hand, various solid waste can be effectively treated through the method, and on the other hand, the use amount of the solid waste is reduced; on the one hand, the solid waste can be converted into a product with a high additional value, full utilization of resources is achieved, on the other hand, the stacking cost of the solid waste can be reduced, the negative influence of the solid waste on the environment is reduced, and meanwhile a large number of resources are saved.

Description

Technical Field

[0001] The invention belongs to the technical field of bulk solid waste geopolymer loess curing agent, and in particular relates to a geopolymer loess curing agent formula based on multi-element bulk solid waste and a preparation method thereof. Background Art

[0002] With the rapid growth of my country's national economy, many highways have entered the stage of major and medium-sized repairs and are in urgent need of reconstruction and expansion to enhance their service capacity. However, highway reconstruction and expansion projects of this scale will lead to the generation of a large amount of waste concrete and fly ash gravel waste. In the process of crushing and processing these wastes to produce recycled coarse aggregate, about 15% to 20% of the waste will generate fine powder with a particle size of less than 0.075mm. Unfortunately, most of this waste is directly transported to the suburbs for stacking or landfill without being processed, which not only occupies a large amount of land resources and high processing costs, but also because of the fine particles, it is easy to spread in the air with airflow, causing air pollution.

[0003] In addition, with the vigorous advancement of my country's modern industrialization process, the amount of industrial solid waste generated has increased year by year, but the overall utilization rate is relatively low. If these solid wastes cannot be disposed of in a timely and effective manner and converted into valuable resources, it will lead to serious resource waste and environmental pollution problems. In the current situation where high-quality resources are gradually depleted, there is an urgent need to explore ways to utilize these solid wastes with high added value.

[0004] At present, geopolymer materials have been widely used in many fields such as transportation, industry, agriculture, mining, oil well cement and waste management (including radioactive waste treatment and toxic metal solidification); soil solidifiers, as a new type of energy-saving and environmentally friendly engineering material synthesized from a variety of inorganic and organic materials, can independently bond soil materials to improve their strength. In view of the characteristics of geopolymers, they have great potential in soil solidification. Although there are not many reports on their application as soil solidifiers, single-component geopolymer solidifiers prepared from engineering solid waste and industrial waste residues through geopolymerization reactions can not only efficiently recycle various solid wastes, but also help save original resources and protect the environment.

[0005] Loess solidifier is a material used to improve the properties of loess foundation and is usually used in civil engineering and construction projects. Loess is a type of soil that is easily deformed and dissolved under natural conditions, so some methods are needed to enhance its mechanical properties and stability. The role of the solidifier is to change the properties of loess through chemical reactions or physical effects to make it more suitable for engineering construction. In recent years, the method of producing geopolymer cementitious materials through geopolymerization using various industrial wastes has shown its unique advantages. This material not only has excellent mechanical properties, but also has a simple preparation process, low energy consumption, and low carbon emissions. The raw material source of geopolymer is abundant. Any mineral material rich in silicon (Si) and aluminum (Al) and industrial solid waste can be used to synthesize geopolymer materials. Waste concrete and waste fly ash crushed stone recycled powder mainly contain unhydrated or hydrated cement stone and coarse and fine aggregate powder. Its chemical composition is mainly CaO, SiO2 and Al2O3, which meets the basic properties required for the preparation of geopolymers. Therefore, it can be used as a silicon-aluminum raw material for the preparation of geopolymer cementitious materials, showing broad application potential.

[0006] The loess curing agent involved in the invention is an alkaline composite loess curing agent, which is easy to use, can well stabilize collapsible loess, and is particularly suitable for loess in Gansu Province; the loess curing agent is non-toxic and harmless, has a small amount of use, and has obvious effect; the loess curing agent of the invention is used to stabilize collapsible loess, which can significantly improve the compressive strength and deformation resistance of the loess; the unburned loess curing bricks made of the loess curing agent can be used as slope protection bricks, which can improve the defects of loess being easy to deform and weak in shearing resistance, and can save a large amount of traditional road construction materials such as lime and cement. Summary of the invention

[0007] The purpose of the present invention is to provide a geopolymer loess solidifier formula based on multiple bulk solid wastes and a preparation method thereof. By providing a geopolymer solidifier based on multiple solid wastes and a preparation method thereof, the solidifier is mixed with water to allow an excitation component and a solidifying material component to undergo a geopolymerization reaction to generate NASH geopolymer gel and CSH gel, which tightly bind the soil particles together to form a stable solidified body; and the preparation process is simple, low-cost, environmentally friendly and efficient, which solves the problem that the amount of existing industrial solid waste generated increases year by year, but the overall utilization rate is relatively low. If these solid wastes cannot be disposed of in a timely and effective manner and converted into valuable resources, it will cause serious resource waste and environmental pollution problems.

[0008] In order to solve the above technical problems, the present invention is achieved through the following technical solutions:

[0009] The present invention discloses a geopolymer loess solidifying agent formula based on multi-component bulk solid waste and a preparation method thereof, which comprises the following components calculated by weight: 50-70 parts of a solidifying material component, 10-30 parts of a reinforcing component, and 5-25 parts of an exciting component; the solidifying material component is fly ash and the particle size of the solidifying material component is less than 300 μm; the reinforcing component is rice husk ash (main component SiO2); the exciting component is at least one of analytically pure solids of desulfurized gypsum and slaked lime.

[0010] As a preferred technical solution, the rice husk ash is crushed and screened to obtain recycled powder with a particle size of less than 0.25 mm, the fly ash is Class I or Class II C fly ash, the desulfurization gypsum is Class II (according to GB / T37785-2019 standard), and the slaked lime is industrial calcium hydroxide (according to HG / T4120-2009 standard).

[0011] As a preferred technical solution, the formula of a geopolymer loess curing agent based on multi-component bulk solid waste and its preparation method include the following operating steps: first weigh the curing material component and the reinforcing component according to the ratio, place them in a dry powder mixer and stir them evenly, then add the excitation component and stir them evenly, then place the solid mixture on a grinder and grind it for 30 minutes to make a dry powder with a fineness of 200-300 mesh, so as to obtain a single-component geopolymer curing agent.

[0012] As a preferred technical solution, the present invention also provides the application of the above-mentioned multi-solid waste geopolymer curing agent or the multi-solid waste geopolymer curing agent prepared by the above-mentioned method, the multi-solid waste geopolymer curing agent is added to the loess to be solidified, fully mixed, added with a proper amount of water and stirred evenly, and compacted to obtain geopolymer-solidified soil.

[0013] As a preferred technical solution, the amount of water added is 25%-40% of the mass of the geopolymer curing agent, and the amount of the geopolymer curing agent added is 9%-18% of the mass of the soil material to be cured.

[0014] The present invention has the following beneficial effects:

[0015] (1) In the past, most rice husk ash was treated by piling it in farmland, which is difficult to rot in the natural state. The general treatment method is to burn rice husk as fertilizer or discharge it into ditches, causing air, land and water pollution. However, this application uses rice husk ash and bulk solid waste as the main raw materials to prepare a single-component geopolymer curing agent, and the amount of solid waste used exceeds 80%. On the one hand, this method can effectively treat a variety of solid wastes and convert them into products with high added value, thereby realizing full utilization of resources. On the other hand, it can also reduce the cost of solid waste accumulation and reduce its negative impact on the environment, while saving a lot of resources; therefore, this method has significant economic, social and environmental benefits.

[0016] (2) By mixing rice husk ash with bulk solid waste and utilizing the alkali excitation effect, the materials with different characteristics are coordinated and regulated to achieve a cumulative effect. This results in the orderly distribution of the hydration products of the curing agent in time and space, and after being evenly mixed with the soil, a dense and high-strength solidified body is formed.

[0017] (3) This multi-solid waste geopolymer curing agent material exhibits the characteristics of high early strength and fast solidification time; its preparation process is simple and low cost, and it also has the advantages of environmental protection, high efficiency and resource recycling, so it has broad application prospects.

[0018] (4) The solid alkali activator used in this application is used to prepare the multi-solid waste geopolymer curing agent, which is more conducive to practical engineering application and convenient for large-scale promotion and application compared with conventional liquid alkali activators.

[0019] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0021] Figure 1 This is a table showing the main chemical components and contents of each material in a geopolymer loess curing agent formula based on multiple bulk solid wastes and a preparation method thereof according to the present invention. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] Embodiment 1

[0024] See also Figure 1As shown, the present invention is a geopolymer loess solidifier formula based on multi-bulk solid waste and a preparation method thereof, which comprises the following components, calculated by weight: 50-70 parts of a solidifying material component, 10-30 parts of a reinforcing component, and 5-25 parts of an exciting component; the solidifying material component is fly ash and the particle size of the solidifying material component is less than 300 μm; the reinforcing component is rice husk ash (main component SiO2); the exciting component is at least one of analytically pure solids of desulfurized gypsum and slaked lime.

[0025] Rice husk ash is crushed and screened to obtain recycled powder with a particle size of less than 0.25 mm. The fly ash is Class I or Class II C fly ash, the desulfurized gypsum is Class II (according to GB / T37785-2019 standard), and the slaked lime is industrial calcium hydroxide (according to HG / T4120-2009 standard).

[0026] A geopolymer loess curing agent formula based on multiple bulk solid wastes and a preparation method thereof, comprising the following steps: firstly weighing a curing material component and a reinforcing component according to a proportion, placing them in a dry powder mixer and stirring them evenly, then adding an exciting component and stirring them evenly, and then placing the solid mixture on a grinder and grinding it for 30 minutes to make a dry powder with a fineness of 200-300 meshes, thereby obtaining a single-component geopolymer curing agent.

[0027] The present invention also provides the application of the above-mentioned multi-solid waste geopolymer curing agent or the multi-solid waste geopolymer curing agent prepared by the above-mentioned method, wherein the multi-solid waste geopolymer curing agent is added to the loess to be cured, mixed thoroughly, an appropriate amount of water is added and stirred evenly, and geopolymer-cured soil is obtained after compaction.

[0028] The amount of water added is 25%-40% of the mass of the geopolymer curing agent, and the amount of the geopolymer curing agent added is 9%-18% of the mass of the soil material to be cured.

[0029] Embodiment 2

[0030] A geopolymer curing agent based on multi-solid waste and a preparation method thereof, comprising the following components: 70 parts of fly ash, 20 parts of desulfurized gypsum and 10 parts of rice husk ash.

[0031] The preparation method comprises the following steps:

[0032] (1) Prepare the curing agent: weigh 70 parts of fly ash and 20 parts of desulfurized gypsum, place them in a dry powder mixer and stir them for 15 minutes, then add 10 parts of rice husk ash, stir them for another 15 minutes, and then grind the solid mixture in a grinder for 30 minutes to make a dry powder with a fineness of 200-300 mesh, thus obtaining the multi-solid waste geopolymer curing agent.

[0033] (2) Molding: Add the prepared multi-solid waste geopolymer curing agent into the loess to be cured, mix thoroughly, add an appropriate amount of water and stir evenly, compact it to obtain cured loess, and control the amount of water added to 30% of the mass of the dry powder curing agent, and the amount of curing agent added to 12% of the mass of the soil to be cured.

[0034] Embodiment 3

[0035] A geopolymer curing agent based on multi-solid waste and a preparation method thereof, comprising the following components: 70 parts of fly ash, 20 parts of slaked lime and 10 parts of rice husk ash.

[0036] The preparation method comprises the following steps:

[0037] (1) Preparation of curing agent: Weigh 70 parts of fly ash and 20 parts of slaked lime, place them in a dry powder mixer and stir them for 15 minutes, then add 10 parts of rice husk ash and stir them for another 15 minutes, then place the solid mixture in a grinder and grind it for 30 minutes to make a dry powder with a fineness of 200-300 mesh, thus obtaining the multi-solid waste geopolymer curing agent.

[0038] (2) Molding: Add the prepared multi-solid waste geopolymer curing agent into the loess to be cured, mix thoroughly, add an appropriate amount of water and stir evenly, compact it to obtain a cured soil body, and control the amount of water added to 40% of the mass of the dry powder curing agent and the amount of curing agent added to 15% of the mass of the loess to be cured.

[0039] Embodiment 4

[0040] A geopolymer curing agent based on multi-solid waste and a preparation method thereof, comprising the following components: 70 parts of fly ash, 15 parts of slaked lime, 5 parts of desulfurized gypsum and 10 parts of rice husk ash.

[0041] The preparation method comprises the following steps:

[0042] (1) Preparation of curing agent: Weigh 70 parts of fly ash, 15 parts of slaked lime and 5 parts of desulfurized gypsum, place them in a dry powder mixer and stir them for 15 minutes, then add 10 parts of rice husk ash and stir them for another 15 minutes, then place the solid mixture in a grinder and grind it for 30 minutes to make a dry powder with a fineness of 200-300 mesh, thus obtaining a multi-solid waste geopolymer curing agent.

[0043] (2) Molding: Add the prepared multi-solid waste geopolymer curing agent into the loess to be cured, mix thoroughly, add an appropriate amount of water and stir evenly, compact it to obtain a cured soil body, and control the amount of water added to 30% of the mass of the dry powder curing agent and the amount of curing agent added to 15% of the mass of the loess to be cured.

[0044] A specific application of this embodiment is: using fly ash to prepare geopolymer with low strength at room temperature, and activating and modifying the fly ash by adding at least one of desulfurized gypsum and slaked lime to analyze pure solids, which helps to generate more NASH geopolymer gel and C-(A)-SH gel, among which the C-(A)-SH gel has a higher content. The two gels interact with each other and jointly regulate and enhance the density and adhesion of the material. After mixing with the soil, they tightly wrap the soil particles to form a dense solidified body in the microstructure.

[0045] It is worth noting that in the above system embodiment, the various units included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of the present invention.

[0046] In addition, those skilled in the art can understand that all or part of the steps in the above-mentioned embodiments can be completed by instructing related hardware through a program, and the corresponding program can be stored in a computer-readable storage medium.

[0047] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific implementation methods described. Obviously, many modifications and changes can be made according to the content of this specification. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can understand and use the present invention well. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A single-component geopolymer curing agent based on multi-solid waste, calculated by weight, comprises the following components: 50-70 parts of a curing material component, 10-30 parts of a reinforcing component, and 5-25 parts of an exciting component; the curing material component is fly ash and the particle size of the curing material component is less than 300 μm; the reinforcing component is rice husk ash (main component SiO2); the exciting component is at least one of analytically pure solids of desulfurized gypsum and slaked lime.

2. According to the formula of a geopolymer loess solidifier based on multi-bulk solid waste and its preparation method according to claim 1, the rice husk ash is crushed and screened to obtain a recycled powder with a particle size of less than 0.25 mm, the fly ash is Class I or Class II C fly ash, the desulfurized gypsum is Class II (according to GB / T37785-2019 standard), and the slaked lime is industrial calcium hydroxide (according to HG / T4120-2009 standard).

3. According to claim 1, a geopolymer loess curing agent formula based on multi-component bulk solid waste and its preparation method include the following steps: first weigh the curing material component and the reinforcing component according to the ratio, place them in a dry powder mixer and stir them evenly, then add the excitation component, stir them evenly, and then place the solid mixture on a grinder and grind it for 30 minutes to make a dry powder with a fineness of 200-300 mesh, so as to obtain a single-component geopolymer curing agent.

4. According to the formula of a geopolymer loess solidifier based on multi-component bulk solid waste and its preparation method as described in claim 3, the present invention also provides the use of the above-mentioned multi-component solid waste geopolymer solidifier or the multi-component solid waste geopolymer solidifier prepared by the above-mentioned method, the multi-component solid waste geopolymer solidifier is added into the loess to be solidified, mixed thoroughly, added with an appropriate amount of water and stirred evenly, and compacted to obtain geopolymer-solidified soil.

5. According to the formula of the geopolymer loess curing agent based on multi-component bulk solid waste and its preparation method as described in claim 4, the amount of water added is 25%-40% of the mass of the geopolymer curing agent, and the amount of the geopolymer curing agent is 9%-18% of the mass of the soil material to be cured.

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