Solid waste-based stable muck gravel material and preparation method thereof

Abstract

The invention relates to a solid-waste-based stable muck gravel material and a preparation method thereof.The solid-waste-based stable muck gravel material comprises a solid raw material and a liquid raw material, and the solid raw material comprises muck, waste gravel and a solid-waste-based curing agent; the solid waste-based curing agent comprises the following raw materials in percentage by weight: 30-50% of granulated blast furnace slag powder, 15-30% of steel slag, 15-30% of magnesium slag, 10-20% of fluorgypsum and 0.01-0.02% of an active catalyst. According to the solid-waste-based stable muck gravel material and the preparation method thereof, solid waste materials such as granulated blast furnace slag, steel slag, magnesium slag and fluorgypsum are adopted, the solid waste utilization rate is high, the problem that solid waste such as steel slag and magnesium slag is difficult to effectively utilize is solved, the solid-waste-based curing agent is utilized to stabilize building muck and waste garbage gravel to replace a traditional water-stable material, and the solid-waste-based stable muck gravel material is environmentally friendly. And the problem that the construction muck and the waste rubble cannot be effectively digested is effectively solved.

Description

Technical Field

[0001] The present invention relates to the technical field of road engineering materials, and in particular to a solid waste-based stabilized muck gravel material and a preparation method thereof. Background Art

[0002] With the rapid development of urban construction, a large amount of solid waste such as construction muck has been generated. Traditional treatment methods are mostly landfilling or stacking, which not only occupy a large amount of land resources but also may cause environmental pollution. At the same time, in the construction of road bases, common materials such as cement-stabilized gravel consume a large amount of energy and natural resources during production, and their durability and environmental protection performance need to be further improved. Therefore, it is of great practical significance to develop a road base stabilizing material that utilizes solid waste and has excellent performance. Summary of the Invention

[0003] The technical problem to be solved by the present invention is: in order to overcome the deficiencies in the prior art, to provide a solid waste-based stabilized muck gravel material and a preparation method thereof, which adopt solid waste materials such as granulated blast furnace slag, steel slag, magnesium slag, and fluorogypsum, with a high utilization rate of solid waste, and solve the problem that solid wastes such as steel slag and magnesium slag are difficult to be effectively utilized.

[0004] The technical solution adopted by the present invention is: a solid waste-based stabilized muck gravel material, including solid raw materials and liquid raw materials, wherein the solid raw materials include muck, waste gravel, and a solid waste-based curing agent; the solid waste-based curing agent includes the following raw materials in weight percentages: 30-50% of granulated blast furnace slag powder, 15-30% of steel slag, 15-30% of magnesium slag, 10-20% of fluorogypsum, and 0.01-0.02% of an active catalyst.

[0005] A preparation method of a solid waste-based stabilized muck gravel material includes the following steps:

[0006] Step 1, mixing granulated blast furnace slag powder, magnesium slag, steel slag, fluorogypsum, and an active catalyst according to a certain weight percentage and grinding them to an average particle size of about 8 μm;

[0007] Step 2, mixing muck, waste gravel, and a solid waste-based curing agent according to a certain ratio;

[0008] Step 3, adjusting the mass of the liquid raw materials according to the optimal moisture content of the mixture, and the mass of the liquid raw materials is 8%-12% of the mass of the solid raw materials;

[0009] Step 4, first dry-mixing muck, waste gravel, and a solid waste-based curing agent for 3-5 minutes, and then adding the liquid raw materials and wet-mixing muck, waste gravel, and a solid waste-based curing agent for 8-10 minutes;

[0010] Step 5: Load the mixture in Step 4 into a test mold and compact it to a compaction degree of ≥95%.

[0011] Further specifically defined, in the above technical solution, the solid raw materials, by mass, include 9 parts of construction waste soil, waste crushed stones and 1 part of solid waste-based curing agent.

[0012] Further specifically defined, in the above technical solution, the liquid raw material is water.

[0013] Further specifically defined, in the above technical solution, in the granulated blast furnace slag powder, the silicon-aluminum components account for 44.6% of the total oxides, and calcium oxide accounts for 40.2% of the total oxides.

[0014] Further specifically defined, in the above technical solution, the components of the steel slag are CaO and Fe2O3.

[0015] Further specifically defined, in the above technical solution, the components of the magnesium slag are MgO and CaO.

[0016] Further specifically defined, in the above technical solution, the components of the fluorogypsum are CaSO4.

[0017] Further specifically defined, in the above technical solution, the active catalyst is a mixture of alkali metal lactate and organic amines.

[0018] The beneficial effects of the present invention are as follows: high solid waste utilization rate, effectively disposing of construction waste soil and construction waste crushed stones, good economy, high strength and high stability, specifically as follows:

[0019] I. Reuse of solid waste materials, energy conservation and emission reduction, good economy: The solid waste-based stabilized construction waste soil and crushed stone materials have a high solid waste utilization rate, greatly reducing the accumulation of solid waste and releasing land resources;

[0020] II. Effectively disposing of construction waste soil and waste crushed stones: The solid waste-based stabilized construction waste soil and crushed stone materials use solid waste materials to stabilize construction waste soil and construction waste crushed stones to replace traditional water-stabilized materials, effectively disposing of construction waste soil and construction waste crushed stones;

[0021] III. The comprehensive cost of the solid waste-based stabilized construction waste soil and crushed stone materials is low, with better economy: For the problems of high cost of traditional cement-based stabilized materials, high energy consumption and high carbon emissions in cement production, industrial solid waste is used to replace traditional cementitious materials to reduce costs and relieve environmental pressure. Specific Embodiments

[0022] The following details the embodiments of the present invention. The embodiments are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following embodiments.

[0023] A solid waste-based stabilized muck gravel material of the present invention comprises solid raw materials and liquid raw materials. The solid raw materials include muck, waste gravel, and a solid waste-based curing agent. The mass of the liquid raw materials is 8% - 12% of the mass of the solid raw materials, adjusted according to the optimum moisture content of the mixture. The solid waste-based curing agent comprises the following raw materials in weight percentages: granulated blast furnace slag powder 30 - 50%, steel slag 15 - 30%, magnesium slag 15 - 30%, fluorogypsum 10 - 20%, and active catalyst 0.01 - 0.02%.

[0024] Preferably, by mass, the solid raw materials include 9 parts of muck, waste gravel, and 1 part of the solid waste-based curing agent. The liquid raw material is water.

[0025] The siliceous and aluminous components in the granulated blast furnace slag powder account for about 44.6% of the total oxides, and calcium oxide accounts for about 40.2% of the total oxides, having certain hydraulicity and high activity.

[0026] Steel slag is a by-product generated during the steel smelting process, and its main components are CaO and Fe2O3.

[0027] Magnesium slag is a solid waste generated during the magnesium smelting or magnesium alloy production process, and its main components are MgO and CaO.

[0028] Fluorogypsum is an industrial by-product gypsum generated during the hydrogen fluoride production process, and its main component is CaSO4.

[0029] The active catalyst is a mixture of alkali metal lactate and organic amines.

[0030] Among them, the granulated blast furnace slag powder is rich in active components such as calcium oxide (CaO), silicon dioxide (SiO2), and aluminum oxide (Al2O3). In an alkaline environment, these active components will undergo a hydration reaction to generate cementitious substances such as calcium silicate hydrate and calcium aluminate hydrate, firmly bonding particles such as muck and gravel together and improving the strength of the stabilized material. The slag particles are fine and can fill the pores between the muck and gravel, making the structure more dense and improving the compactness and impermeability of the material. Specifically, in an alkaline environment, the active silicon dioxide (SiO2) and aluminum oxide (Al2O3) in the granulated blast furnace slag powder used in the solid waste-based curing agent will undergo a pozzolanic reaction with calcium hydroxide (Ca(OH)2) generated by the hydration of cement to generate cementitious products such as calcium silicate hydrate and calcium aluminate hydrate. These products can fill the pores of the muck gravel, improving the compactness and strength of the material.

[0031] Magnesium oxide (MgO) in magnesium slag undergoes a hydration reaction when encountering water to form magnesium hydroxide, which has a certain gelling property, can bond particles, and enhance the strength of the material. At the same time, magnesium oxide reacts with active silica (SiO2), alumina (Al2O3), etc. in the system under alkaline conditions to form gelling substances such as magnesium silicate hydrate (MgSiO3) and magnesium aluminate hydrate, further improving the gelling performance and strength of the material. An appropriate amount of magnesium slag can adjust and stabilize the setting time of the material, providing more ample time for construction. Specifically, the magnesium slag used in the solid waste-based curing agent contains a certain amount of magnesium oxide (MgO), which will undergo a carbonation reaction with carbon dioxide (CO2) in the air to form magnesium carbonate (MgCO3). The formation of magnesium carbonate (MgCO3) can fill some pores and at the same time increase the alkalinity of the material, providing a favorable alkaline environment for the reaction of other gelling materials. Mineral components such as dicalcium silicate (2CaO·SiO2) in magnesium slag will undergo a hydration reaction under water-containing conditions to form gelling substances such as calcium silicate hydrate, which helps to improve the strength of the material. In addition, the active magnesium oxide (MgO) in magnesium slag can also react with water to form magnesium hydroxide (Mg(OH)2), and the growth of magnesium hydroxide (Mg(OH)2) crystals can generate a certain expansion pressure, filling pores to a certain extent.

[0032] Steel slag contains mineral components such as tricalcium silicate (3CaO·SiO2) and dicalcium silicate (2CaO·SiO2). These components have a certain hydraulic gelling property and can undergo a hydration reaction in stabilized soil and gravel to produce gelling substances, improving the strength and stability of the material. Steel slag has relatively high strength and hardness, and its particles can play a role in skeleton support in the stabilized material, enhancing the overall structural strength of the material and improving the ability to resist external force damage. Specifically, the steel slag used in the solid waste-based curing agent contains cement clinker minerals such as tricalcium silicate (3CaO·SiO2) and dicalcium silicate (2CaO·SiO2). These minerals will undergo hydrolysis and hydration reactions after contacting with water to form hydration products such as calcium silicate hydrate and calcium hydroxide, which is similar to the hydration reaction of cement and can provide early strength and cementing action. The surface of steel slag carries a certain charge and can interact with ions and water molecules on the surface of soil and gravel through ion exchange and adsorption, enhancing the interfacial bonding force between steel slag and soil and gravel, thereby improving the overall performance of the stabilized material.

[0033] Calcium sulfate (CaSO4) in fluorogypsum can be used as an activator to promote the hydration reaction of active components such as slag and steel slag, accelerate the formation of cementitious substances, and thus improve the early strength of materials. Under certain conditions, fluorogypsum will react with components such as aluminate in the system to form cementitious substances such as ettringite. Ettringite has good filling and cementing effects, can fill pores, and improve the density and strength of materials. The calcium sulfate in fluorogypsum can react with calcium hydroxide generated during the hydration of cement to form a protective film on the surface of cement particles, delaying the hydration rate of cement and playing a retarding role, so that the material has enough time for operations such as mixing, transportation, and compaction during construction. Specifically, in an alkaline environment, the calcium sulfate (CaSO4) in the solid waste-based curing agent will react with tricalcium aluminate (3CaO·Al2O3) and calcium hydroxide (Ca(OH)2) generated by cement hydration to form ettringite. Ettringite is a needle-like crystal, and it will produce volume expansion during the formation process, fill the pores of muck and crushed stones, and at the same time play a cementing role to improve the early strength of materials. In addition, it can adjust the setting time of cement, making the material have better work performance during construction, such as extending the operable time and improving fluidity. In addition, fluorogypsum can also interact with other mineral components to optimize the microstructure of the material and improve its later strength and durability.

[0034] The active catalyst used in the solid waste-based curing agent reduces the reaction activation energy, enabling the active components (such as silicon and aluminum oxides) in the solid waste to hydrate more rapidly, generating more cementitious substances such as ettringite and C-S-H gel, thereby enhancing the structural strength and compactness of the material.

[0035] The solid waste-based stabilized muck and crushed stone material is an engineering stabilized material mainly composed of solid wastes such as construction muck and waste crushed stones. By adding a solid waste-based curing agent and through scientific proportioning and process treatment, its core goal is to convert low-value solid wastes into high-value building materials, effectively solve the problem of the inability to dispose of construction muck and waste crushed stones, and has good economy.

[0036] The waste construction waste crushed stones are crushed and the gradation is adjusted to a continuous gradation of 5 - 30 mm. The solid waste-based curing agent is proportionally mixed and ground to an average particle size of about 8 μm.

[0037] Example 1

[0038] The weight percentages of the components of the solid waste-based curing agent are as follows: granulated blast furnace slag powder 40%, magnesium slag 20%, steel slag 25%, fluorogypsum 15%, and active catalyst 0.01%; the ratio of muck ∶ waste crushed stones ∶ solid waste-based curing agent = 54 ∶ 36 ∶ 10, and the mass of water is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal water content of the mixture). Dry mix the muck, crushed stones, and curing agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0039] Example 2

[0040] The weight percentages of the components of the solid waste-based curing agent are as follows: granulated blast furnace slag powder 35%, magnesium slag 25%, steel slag 20%, fluorogypsum 20%, and active catalyst 0.02%; the ratio of muck ∶ waste crushed stones ∶ solid waste-based curing agent = 54 ∶ 36 ∶ 10, and the mass of water is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal water content of the mixture). Dry mix the muck, crushed stones, and curing agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0041] Example 3

[0042] The weight percentages of the components of the solid waste-based curing agent are as follows: granulated blast furnace slag powder 45%, magnesium slag 15%, steel slag 20%, fluorogypsum 20%, and active catalyst 0.01%; the ratio of muck ∶ waste crushed stones ∶ solid waste-based curing agent = 54 ∶ 36 ∶ 10, and the mass of water is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal water content of the mixture). Dry mix the muck, crushed stones, and curing agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0043] Example 4

[0044] The weight percentages of the components of the solid waste-based curing agent are as follows: granulated blast furnace slag powder 30%, magnesium slag 30%, steel slag 20%, fluorogypsum 20%, and active catalyst 0.02%; the ratio of muck ∶ waste crushed stones ∶ solid waste-based curing agent = 54 ∶ 36 ∶ 10, and the mass of water is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal water content of the mixture). Dry mix the muck, crushed stones, and curing agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0045] Comparative Example 1

[0046] The weight percentages of the components of the solid waste-based solidifying agent are as follows: granulated blast furnace slag powder 40%, magnesium slag 20%, steel slag 25%, fluorogypsum 15%, and active catalyst 0.01%; the ratio of muck: waste crushed stones: solid waste-based solidifying agent is 63:27:10, and the water quality is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal moisture content of the mixture.) Dry mix the muck, crushed stones, and solidifying agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0047] Comparative Example 2

[0048] The weight percentages of the components of the solidifying agent are as follows: P.O42.5 cement 100%; the ratio of muck: waste crushed stones: solid waste-based solidifying agent is 54:36:10, and the water quality is 8% - 12% of the mass of the solid raw materials. (Adjust according to the optimal moisture content of the mixture.) Dry mix the muck, crushed stones, and solidifying agent for 3 - 5 minutes, add water and wet mix for 8 - 10 minutes; load into a test mold and compact to a compaction degree ≥ 95%, and cure for 7 days in an environment with a temperature of 20 - 25°C and a humidity ≥ 90%.

[0049] The performance of the solid waste-based stabilized muck and crushed stone materials prepared in Example 1, Example 2, Example 3, and Example 4 of the present invention and Comparative Example 1 and Comparative Example 2 is shown in the following table:

[0050]

[0051]

[0052] As can be seen from the above table, the solid waste-based stabilized muck and crushed stone materials of the present invention have good strength, and the obtained 7-day unconfined compressive strength can reach 4.8 - 5.5 MPa. The frost resistance and impermeability are good, and there are certain performance advantages compared with cement stabilization. It can be seen from Example 1 and Comparative Example 1 that increasing the proportion of muck can increase the strength and other properties of the solid waste-based stabilized muck and crushed stone materials to a certain extent.

[0053] The above is only a preferred specific embodiment 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, makes equivalent substitutions or changes, and should be covered by the protection scope of the present invention.

Claims

1. A solid waste-based stabilized muck gravel material, characterized in that, It includes solid raw materials and liquid raw materials. The solid raw materials include construction waste soil, waste crushed stones and solid waste-based curing agent; The solid waste-based curing agent includes raw materials in the following weight percentages: granulated blast furnace slag powder 30 - 50%, steel slag 15 - 30%, magnesium slag 15 - 30%, fluorogypsum 10 - 20%, active catalyst 0.01 - 0.02%.

2. The solid waste-based stabilized muck gravel material according to claim 1, wherein: The solid raw materials, by mass, include 9 parts of construction waste soil, waste crushed stones and 1 part of solid waste-based curing agent.

3. The solid waste-based stabilized muck gravel material according to claim 1, wherein: The liquid raw material is water.

4. A solid waste-based stabilized muck gravel material according to claim 1, characterized in that: In the granulated blast furnace slag powder, the silicon-aluminum components account for 44.6% of the total oxides, and calcium oxide accounts for 40.2% of the total oxides.

5. The solid waste-based stabilized muck gravel material according to claim 1, characterized in that: The components of the steel slag are CaO and Fe2O3.

6. The solid waste-based stabilized muck gravel material according to claim 1, characterized in that: The components of the magnesium slag are MgO and CaO.

7. The solid waste-based stabilized muck gravel material according to claim 1, wherein: The components of the fluorogypsum are CaSO4.

8. The solid waste-based stabilized muck gravel material according to claim 1, characterized in that: The active catalyst is a mixture of alkali metal lactate and organic amines.

9. A preparation method of the solid waste-based stabilized muck gravel material as described in claim 1, characterized in that, It includes the following steps: Step 1: Mix the granulated blast furnace slag powder, magnesium slag, steel slag, fluorogypsum and active catalyst according to a certain weight percentage and grind them to an average particle size of about 8 μm; Step 2: Mix the construction waste soil, waste crushed stones and solid waste-based curing agent according to a certain ratio; Step 3: Adjust the mass of the liquid raw material according to the optimal moisture content of the mixture. The mass of the liquid raw material is 8% - 12% of the mass of the solid raw materials; Step 4: First dry-mix the construction waste soil, waste crushed stones and solid waste-based curing agent for 3 - 5 minutes, then add the liquid raw material and wet-mix the construction waste soil, waste crushed stones and solid waste-based curing agent for 8 - 10 minutes; Step 5: Load the mixture in Step 4 into a test mold and compact it to a compaction degree ≥ 95%.

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