Coal gasification slag cementing material composite multi-solid-waste foundation pit base material as well as preparation method and application thereof

Abstract

The invention discloses a coal gasification slag cementing material composite multi-solid waste foundation pit base material, a preparation method and application, the coal gasification slag cementing material composite multi-solid waste foundation pit base material comprises a cementing material and further comprises composite multi-solid waste, and the preparation method specifically comprises the following steps that a factory is prepared; the preparation method comprises the following steps: 1, drying the components of the cementing material by a dry method, and mixing and stirring for 15-20 minutes; 2, uniformly mixing and stirring the composite multi-solid waste according to a dry method for 8-10 minutes; 3, mixing and stirring the two steps; step 4, putting into a wet stirring tank, adding water and stirring; 5, adding an aluminum powder foaming activator; and 6, after the base material is self-leveled into a horizontal plane and fixed and formed, the base material is covered with a curing film, and the curing time is 72-96 hours. Compared with the prior art, the method has the advantages that a method for changing the cementing material cement in the concrete material as a main component is adopted, the coal-based gasified slag is taken as a main component of the cementing material, the purpose and the effect of the coal-based gasified slag are to reduce the proportion and the dosage of the cement so as to achieve the purposes of low carbon and carbon reduction, and economic benefits and social benefits are achieved.

Description

Technical Field

[0001] This invention relates to the field of comprehensive utilization technology of coal-based gasification slag, specifically to coal gasification slag binder composite multi-solid waste foundation material, preparation method and application. Background Technology

[0002] Coal gasification is a crucial part of coal chemical industry. It involves using coal or coke as raw material and oxygen (air, oxygen-enriched, or pure oxygen), steam, or hydrogen as gasifying agents to convert coal or coke into syngas through physical and chemical reactions under high-temperature conditions. The coal gasification process generates a large amount of gasification slag, primarily composed of unburned carbon and ash.

[0003] With the rapid development of the coal chemical industry, the emissions of coal-based gasification slag and other coal-based solid wastes are increasing. Currently, the main methods for disposing of coal gasification slag are landfilling or stockpiling, which causes soil pollution and waste of resources.

[0004] In recent years, a great deal of work has been done in China on the resource utilization of coal gasification slag, such as preparing insulating materials, using it as a blending material, using it for coal mine backfilling, and using the unburned carbon in it as an adsorbent material. Although the research on coal gasification slag has achieved good results, most of it is still in the laboratory research stage or the experimental promotion stage, and cannot achieve large-scale utilization. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned technical problems by providing a composite substrate for coal gasification slag cementitious materials and solid waste foundation pits, its preparation method, and its application, in order to achieve the technical effect of maximizing comprehensive utilization.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0007] A composite solid waste foundation material for coal gasification slag binder, comprising a binder, wherein the binder comprises the following components by mass parts:

[0008] 60-70 parts coal-based gasification slag, 15-20 parts 42.5 sulfoaluminate cement, 10-15 parts industrial waste silica slag, 0.5-1.5 parts polymer grinding aid, 5-10 parts solid waste desulfurization gypsum, and 10-15 parts fly ash.

[0009] It also includes composite multi-solid waste, wherein the components are as follows by mass parts:

[0010] 30-40 parts coal-based gasification slag, 40-50 parts industrial waste silicon slag, 30-40 parts calcium carbide slag, 3-5 parts lime, 1-3 parts aluminum powder, and 3-5 parts aluminum powder foaming agent.

[0011] Furthermore, the particle size of the coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, polymer grinding aid, and fly ash is 400-500 mesh.

[0012] Furthermore, the particle size of the coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, polymer grinding aid, and fly ash is 500 mesh.

[0013] Furthermore, the particle size of the coal-based gasification slag is 40-60 mesh;

[0014] Furthermore, the particle size of industrial waste silicon slag is 20-40 mesh;

[0015] Furthermore, the particle size of calcium carbide slag is approximately 40-60 mesh;

[0016] Furthermore, the lime particle size is 100-200 mesh;

[0017] Furthermore, the aluminum powder has a particle size of 150-200 mesh.

[0018] Furthermore, the coal-based gasification slag has a particle size of 60 mesh, the industrial waste silicon slag has a particle size of 20 mesh, the calcium carbide slag has a particle size of approximately 60 mesh, the lime has a particle size of 200 mesh, and the aluminum powder has a particle size of 200 mesh.

[0019] A method for preparing a composite solid waste foundation pit substrate using coal gasification slag binder is characterized by the following steps: the preparation is carried out separately at two different sites.

[0020] First site: the manufacturing plant;

[0021] Step 1: Dry-dry and mix the coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurized gypsum, and fly ash for 15-20 minutes to ensure that the moisture content of the components in the binder is less than 12%. Then, place the mixed materials into a high-speed grinder and grind for 30-40 minutes to obtain a 400-500 mesh coal-based gasification slag binder.

[0022] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size ratio. Then, dry mix and stir for 8-10 minutes until the moisture content is not higher than 13%.

[0023] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0024] Second site: The site of the substrate preparation and conveying pit;

[0025] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 20-30 parts of water, and mix for 10-15 minutes.

[0026] Step 5: Add 3-5 parts of aluminum powder foaming activator to Step 4, stir for 2-4 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfill.

[0027] Step 6: After the substrate has self-leveled and fixed into a horizontal surface, cover it with a curing film and cure for 72-96 hours.

[0028] The advantages of this invention compared to the prior art are:

[0029] 1. To address the technical challenges of preparing coal-based gasification slag binders and composite multi-solid waste foundation materials to maximize comprehensive utilization;

[0030] 2. Change the cement-based binder in concrete materials to coal-based gasification slag as the main component of the binder. The purpose and function of this change is to reduce the cement ratio and dosage, so as to achieve the goal of low carbon and carbon reduction, which has both economic and social benefits.

[0031] 3. By preparing coal-based gasification slag binder and compounding (grading) multiple solid wastes to prepare foundation pit substrate, it is mainly used for deep foundation pit vertical filling of roads, bridges, tunnels, and large structures. This technology improves the compressive strength, stability, water repellency, weather resistance, leveling, and heat insulation properties of traditional foundation pit filling materials. Detailed Implementation

[0032] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0033] In this invention, materials such as coal-based gasification slag are used as binders to reduce the proportion and amount of cement used, thereby achieving the goal of low carbon emissions and carbon reduction, which has both economic and social benefits.

[0034] The preparation of coal-based gasification slag binder and compounding of multiple solid wastes to prepare foundation pit substrate is mainly used for deep foundation pit vertical filling of roads, bridges, tunnels, and large structures, thus enabling large-scale application.

[0035] A composite substrate for multi-solid waste foundation pits made from coal gasification slag binder, comprising the following components:

[0036] The binder includes: 60-70 parts coal-based gasification slag, 15-20 parts 42.5 sulfoaluminate cement, 10-15 parts industrial waste silica slag, 0.5-1.5 parts polymer grinding aid, 5-10 parts solid waste desulfurization gypsum, and 10-15 parts fly ash.

[0037] Among them, the particle size of coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, polymer grinding aid, and fly ash is 400-500 mesh, preferably 500 mesh, and solid waste desulfurization gypsum must meet the requirements of GB / T21371.

[0038] In this invention, typical but non-limiting mass fractions of coal-based gasification slag are 60, 62, 65, 68, or 70 parts; typical but non-limiting mass fractions of 42.5 sulfoaluminate cement are 15, 16, 18, 19, or 20 parts; typical but non-limiting mass fractions of industrial waste silica slag are 10, 11, 12, 13, 14, or 15 parts; typical but non-limiting mass fractions of polymeric grinding aids are 0.5, 0.8, 1.0, 1.2, 1.4, or 1.5 parts; typical but non-limiting mass fractions of solid waste desulfurization gypsum are 5, 8, 9, or 10 parts; and typical but non-limiting mass fractions of fly ash are 10, 12, 14, or 15 parts.

[0039] It also includes composite solid waste materials: 30-40 parts coal-based gasification slag, 40-50 parts industrial waste silicon slag, 30-40 parts calcium carbide slag, 3-5 parts lime, 1-3 parts aluminum powder, and 3-5 parts aluminum powder foaming agent.

[0040] Among them, the particle size of coal-based gasification slag is 40-60 mesh, the particle size of industrial waste silicon slag is 20-40 mesh, the particle size of calcium carbide slag is about 40-60 mesh, the particle size of lime is 100-200 mesh, and the particle size of aluminum powder is 150-200 mesh.

[0041] In a preferred embodiment, the particle size of the coal-based gasification slag is 60 mesh;

[0042] As a preferred embodiment, the particle size of industrial waste silicon slag is 20 mesh;

[0043] As a preferred embodiment, the particle size of the carbide slag is approximately 60 mesh;

[0044] In a preferred embodiment, the lime particle size is 200 mesh;

[0045] In one preferred embodiment, the aluminum powder has a particle size of 200 mesh;

[0046] In this invention, typical but non-limiting mass fractions of coal-based gasification slag are 30, 32, 34, 36, 38, or 40 parts; typical but non-limiting mass fractions of industrial waste silicon slag are 40, 42, 44, 46, 48, or 50 parts; typical but non-limiting mass fractions of calcium carbide slag are 30, 32, 34, 36, 38, or 40 parts; typical but non-limiting mass fractions of lime are 3, 4, or 5 parts; typical but non-limiting mass fractions of aluminum powder are 1, 2, or 3 parts; and typical but non-limiting mass fractions of aluminum powder foaming agent are 3, 4, or 5 parts.

[0047] The selection of coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, carbide slag, and several other solid wastes as the basic materials for this scheme is all aimed at better resource utilization and industrialization, closely addressing the difficult problems that arise in the process of industry development, promoting the coordinated development of regional society and environment, and driving the development of related industries to generate certain economic benefits.

[0048] Coal-based gasification slag contains unburned carbon with a rough surface, which is beneficial to its compatibility with polymer matrices; the aluminosilicate glass microspheres in industrial waste silicon slag have high chemical reactivity, which can increase the reactive sites and bonding strength with polymer matrices. Compared with commonly used fillers such as heavy calcium carbonate, they do not have sharp edges and will not damage the molecular structure of polymer chains in rubber and plastic processing.

[0049] Example 1:

[0050] The preparation steps are as follows:

[0051] First site: the manufacturing plant;

[0052] Step 1: Dry-dry and mix coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurized gypsum, and fly ash for 15 minutes to make the moisture content of the components in the binder 12%. Then, put the mixed materials into a high-speed grinder and grind for 30 minutes to obtain 400-mesh coal-based gasification slag binder.

[0053] The components are as follows by mass: 60 parts coal-based gasification slag, 15 parts 42.5 sulfoaluminate cement, 10 parts industrial waste silica slag, 0.5 parts polymer grinding aid, 5 parts solid waste desulfurization gypsum, and 10 parts fly ash.

[0054] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size ratio. Then, dry mix and stir for 8 minutes until the moisture content is 13%.

[0055] The components are as follows by mass: 30 parts coal-based gasification slag, 40 parts industrial waste silicon slag, 30 parts calcium carbide slag, 3 parts lime, 1 part aluminum powder, and 3 parts aluminum powder foaming agent.

[0056] The particle size of coal-based gasification slag is 40 mesh, the particle size of industrial waste silicon slag is 20 mesh, the particle size of calcium carbide slag is about 40 mesh, the particle size of lime is 100 mesh, and the particle size of aluminum powder is 150 mesh.

[0057] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0058] Second site: The site of the substrate preparation and conveying pit;

[0059] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 20 parts of water, and mix for 10 minutes.

[0060] Step 5: Add 3 parts of aluminum powder foaming activator to Step 4, stir for 2 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfilling;

[0061] Step 6: After the substrate has self-leveled and fixed into a horizontal plane, cover it with a curing film and cure for 72 hours.

[0062] Example 2:

[0063] The preparation steps are as follows:

[0064] First site: the manufacturing plant;

[0065] Step 1: Dry-dry and mix coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurized gypsum, and fly ash for 16 minutes to make the moisture content of the components in the binder 11%. Then, put the mixed materials into a high-speed grinder and grind for 32 minutes to obtain 450-mesh coal-based gasification slag binder.

[0066] The components are as follows by mass: 62 parts coal-based gasification slag, 18 parts 42.5 sulfoaluminate cement, 12 parts industrial waste silica slag, 0.8 parts polymer grinding aid, 7 parts solid waste desulfurization gypsum, and 12 parts fly ash.

[0067] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the specified proportions. Then, dry mix and stir for 9 minutes until the moisture content is 12%.

[0068] The components are as follows by mass: 32 parts coal-based gasification slag, 42 parts industrial waste silicon slag, 32 parts calcium carbide slag, 4 parts lime, 2 parts aluminum powder, and 4 parts aluminum powder foaming agent.

[0069] The particle size of coal-based gasification slag is 45 mesh, the particle size of industrial waste silicon slag is 25 mesh, the particle size of calcium carbide slag is about 45 mesh, the particle size of lime is 120 mesh, and the particle size of aluminum powder is 160 mesh.

[0070] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0071] Second site: The site of the substrate preparation and conveying pit;

[0072] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 23 parts water, and mix for 12 minutes.

[0073] Step 5: Add 4 parts of aluminum powder foaming activator to Step 4, stir for 3 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfill.

[0074] Step 6: After the substrate has self-leveled and fixed into a horizontal surface, cover it with a curing film and cure for 80 hours.

[0075] Example 3:

[0076] The preparation steps are as follows:

[0077] First site: the manufacturing plant;

[0078] Step 1: Dry-dry and mix coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurization gypsum, and fly ash for 15 minutes to make the moisture content of the components in the binder 12%. Then, put the mixed materials into a high-speed grinder and grind for 30 minutes to obtain 480-mesh coal-based gasification slag binder.

[0079] The components are as follows by mass: 65 parts coal-based gasification slag, 18 parts 42.5 sulfoaluminate cement, 13 parts industrial waste silica slag, 1 part polymer grinding aid, 8 parts solid waste desulfurization gypsum, and 13 parts fly ash.

[0080] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size ratio. Then, dry mix and stir for 10 minutes until the moisture content is 10%.

[0081] The components are as follows by mass: 37 parts coal-based gasification slag, 45 parts industrial waste silicon slag, 35 parts calcium carbide slag, 5 parts lime, 3 parts aluminum powder, and 5 parts aluminum powder foaming agent.

[0082] The particle size of coal-based gasification slag is 50 mesh, that of industrial waste silicon slag is 30 mesh, that of calcium carbide slag is approximately 50 mesh, that of lime is 150 mesh, and that of aluminum powder is 180 mesh.

[0083] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0084] Second site: The site of the substrate preparation and conveying pit;

[0085] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 25 parts of water, and mix for 14 minutes.

[0086] Step 5: Add 5 parts of aluminum powder foaming activator to Step 4, stir for 4 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfill.

[0087] Step 6: After the substrate has self-leveled and fixed into a horizontal plane, cover it with a curing film and cure for 85 hours.

[0088] Example 4:

[0089] The preparation steps are as follows:

[0090] First site: the manufacturing plant;

[0091] Step 1: Dry-dry and mix coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurized gypsum, and fly ash for 18 minutes to make the moisture content of the components in the binder 10%. Then, put the mixed materials into a high-speed grinder and grind for 38 minutes to obtain 500-mesh coal-based gasification slag binder.

[0092] The components are as follows by mass: 68 parts coal-based gasification slag, 19 parts 42.5 sulfoaluminate cement, 14 parts industrial waste silica slag, 1.3 parts polymer grinding aid, 9 parts solid waste desulfurization gypsum, and 14 parts fly ash.

[0093] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size ratio. Then, dry mix and stir for 10 minutes until the moisture content is 10%.

[0094] The components are as follows by mass: 39 parts coal-based gasification slag, 48 parts industrial waste silicon slag, 38 parts calcium carbide slag, 5 parts lime, 3 parts aluminum powder, and 5 parts aluminum powder foaming agent.

[0095] The particle size of coal-based gasification slag is 48 mesh, that of industrial waste silicon slag is 38 mesh, that of calcium carbide slag is approximately 48 mesh, that of lime is 180 mesh, and that of aluminum powder is 190 mesh.

[0096] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0097] Second site: The site of the substrate preparation and conveying pit;

[0098] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 28 parts of water, and mix for 14 minutes.

[0099] Step 5: Add 5 parts of aluminum powder foaming activator to Step 4, stir for 4 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfill.

[0100] Step 6: After the substrate has self-leveled and fixed into a horizontal surface, cover it with a curing film and cure for 90 hours.

[0101] Example 5:

[0102] The preparation steps are as follows:

[0103] First site: the manufacturing plant;

[0104] Step 1: Dry-dry and mix coal-based gasification slag, 42.5 sulfoaluminate cement, polymer grinding aid, desulfurized gypsum, and fly ash for 20 minutes to make the moisture content of the components in the binder 12%. Then, put the mixed materials into a high-speed grinder and grind for 10 minutes to obtain 500-mesh coal-based gasification slag binder.

[0105] The components are as follows by mass: 70 parts coal-based gasification slag, 20 parts 42.5 sulfoaluminate cement, 15 parts industrial waste silica slag, 1.5 parts polymer grinding aid, 10 parts solid waste desulfurization gypsum, and 15 parts fly ash.

[0106] Step 2: Crush the composite solid waste materials, namely coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size ratio. Then, dry mix and stir for 10 minutes until the moisture content is 10%.

[0107] Among them, there are 40 parts of coal-based gasification slag, 50 parts of industrial waste silicon slag, 40 parts of calcium carbide slag, 5 parts of lime, 5 parts of aluminum powder, and 5 parts of aluminum powder foaming agent.

[0108] The particle size of coal-based gasification slag is 60 mesh, the particle size of industrial waste silicon slag is 20 mesh, the particle size of calcium carbide slag is approximately 60 mesh, the particle size of lime is 200 mesh, and the particle size of aluminum powder is 200 mesh.

[0109] Step 3: Mix the coal-based gasification slag binder and composite multi-solid waste obtained in the above two steps to obtain the pre-mixed composite dry powder base material, which is then packaged in bags or dry powder silos and prepared for entry into the second site.

[0110] Second site: The site of the substrate preparation and conveying pit;

[0111] Step 4: Place the pre-mixed composite dry powder base material obtained from the first site into a wet mixing tank, add 30 parts of water, and mix for 15 minutes.

[0112] Step 5: Add 5 parts of aluminum powder foaming activator to Step 4, stir for 4 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit substrate, and pump it to the target foundation pit for landfill.

[0113] Step 6: After the substrate has self-leveled and fixed into a horizontal plane, cover it with a curing film and cure for 96 hours.

[0114] Comparative Example 1:

[0115] This comparative example provides a composite multi-solid waste foundation pit substrate made of coal gasification slag binder, the structure of which is as in Example 1. The composite multi-solid waste foundation pit substrate provided in this example includes the following raw materials by mass parts: First binder: 90 parts of coal-based gasification slag, 25 parts of 42.5 sulfoaluminate cement, 20 parts of industrial waste silica slag, 2 parts of polymer grinding aid, 15 parts of solid waste desulfurization gypsum, and 20 parts of fly ash.

[0116] The second composite solid waste consists of 45 parts coal-based gasification slag, 55 parts industrial waste silicon slag, 45 parts calcium carbide slag, 6 parts lime, 4 parts aluminum powder, and 6 parts aluminum powder foaming agent. The specifications, models, and preparation methods of each raw material in this comparative example are the same as those in Example 1.

[0117] Comparative Example 2:

[0118] This comparative example provides a composite multi-solid waste foundation pit substrate made of coal gasification slag binder, the structure of which is as described in Example 1. The composite multi-solid waste foundation pit substrate provided in this example includes the following raw materials by mass parts: First binder: 50 parts of coal-based gasification slag, 10 parts of 42.5 sulfoaluminate cement, 5 parts of industrial waste silica slag, 0.3 parts of polymer grinding aid, 4 parts of solid waste desulfurization gypsum, and 8 parts of fly ash.

[0119] The second composite solid waste consists of 45 parts coal-based gasification slag, 25 parts industrial waste silicon slag, 30 parts calcium carbide slag, 2 parts lime, 4 parts aluminum powder, and 2 parts aluminum powder foaming agent. The specifications, models, and preparation methods of each raw material in this comparative example are the same as those in Example 1.

[0120] Comparative Example 3:

[0121] This comparative example provides a composite multi-solid waste foundation pit substrate made of coal gasification slag binder, the structure of which is as described in Example 1. The composite multi-solid waste foundation pit substrate provided in this example includes the following raw materials by mass parts: First binder: 40 parts of coal-based gasification slag, 10 parts of 42.5 sulfoaluminate cement, 5 parts of industrial waste silica slag, 0.3 parts of polymer grinding aid, 4 parts of solid waste desulfurization gypsum, and 8 parts of fly ash.

[0122] The second composite solid waste consists of 20 parts coal-based gasification slag, 35 parts industrial waste silicon slag, 20 parts calcium carbide slag, 2 parts lime, 4 parts aluminum powder, and 2 parts aluminum powder foaming agent. The specifications, models, and preparation methods of each raw material in this comparative example are the same as those in Example 1.

[0123] The composite porous adsorption substrates provided in Examples 1-5 and Comparative Examples 1-3 were tested for compressive strength, compressive strength loss, mass loss, impermeability, dry bulk density, and water bleeding rate. The results are shown in Table 1.

[0124] Table 1 Performance Data of Composite Multi-Solid Waste Foundation Substrate Using Coal Gasification Slag Binder

[0125]

[0126]

[0127] By comparing Examples 1-5 and Comparative Examples 1-3, it can be seen that the performance of the pre-mixed composite dry powder base material provided in this invention is as follows: compressive strength of 3-5 MPa, antifreeze properties, 100 cycles of freeze-thaw cycles, compressive strength loss of less than 25%, mass loss of less than 5%, impermeability reaching P8 standard, dry bulk density of 350-450 kg, and water bleeding rate of less than 1%.

[0128] The present invention and its embodiments have been described above. This description is not restrictive. In short, if a person skilled in the art is inspired by this description and designs a similar structure and embodiment without departing from the spirit of the present invention, such design should fall within the protection scope of the present invention.

Claims

1. Coal gasification slag binder composite multi-solid waste foundation pit base material, characterized by: The binder comprises the following components by weight: 60-70 parts of coal-based gasification slag, 15-20 parts of 42.5 sulphoaluminate cement, 10-15 parts of industrial waste silicon slag, 0.5-1.5 parts of polymer grinding aid, 5-10 parts of solid waste desulfurization gypsum, and 10-15 parts of fly ash; It also includes composite multi-solid waste, which includes the following components by mass: 30-40 parts of coal-based gasification slag, 40-50 parts of industrial waste silicon slag, 30-40 parts of carbide slag, 3-5 parts of lime, 1-3 parts of aluminum powder, and 3-5 parts of aluminum powder activating foaming agent.

2. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle sizes of the coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, polymer grinding aid and fly ash are 400-500 meshes.

3. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle size of the coal-based gasification slag, industrial waste silicon slag, solid waste desulfurization gypsum, polymer grinding aid and fly ash is 500 meshes.

4. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle size of the coal-based gasification slag is 40-60 meshes, the particle size of the industrial waste silicon slag is 20-40 meshes, the particle size of the calcium carbide slag is about 40-60 meshes, the particle size of the lime is 100-200 meshes, and the particle size of the aluminum powder is 150-200 meshes.

5. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The coal-based gasification slag has a particle size of 60 meshes.

6. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle size of the industrial waste silicon slag is 20 meshes.

7. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle size of the carbide slag is about 60 meshes.

8. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The lime particle size is 200 meshes.

9. The coal gasification slag binder composite multi-solid waste foundation pit substrate according to claim 1, characterized in that: The particle size of the aluminum powder is 200 meshes.

10. The method for preparing a coal gasification slag binder composite multi-solid waste foundation pit substrate according to any one of claims 1 to 9, characterized in that: The method is carried out in two different sites and is specifically comprised of the following steps: First site: preparation factory; Step 1: dry-dry and mix the coal-based gasification slag, 42.5 sulphoaluminate cement, polymer grinding aid, desulfurized gypsum and fly ash for 15-20 minutes to make the moisture content of the components in the binder lower than 12%, and grind the mixed components in a high-speed grinder for 30-40 minutes to obtain a 400-500 mesh coal-based gasification slag binder; Step 2: crush the composite multi-solid waste, i.e. coal-based gasification slag, industrial waste silicon slag, carbide slag, lime, and aluminum powder, and mix them according to the above mesh size, and stir them evenly for 8-10 minutes according to the dry method, and the moisture content is not higher than 13%; Step 3: Mix and stir the coal-based gasification slag binder and the composite multi-solid waste obtained in the above two steps to obtain the base material pre-mixed composite dry powder base material, which is put into a packaging bag or a dry powder silo to prepare for entering the second site; Second site: preparation of the base material transportation pit site; Step 4: Place the pre-mixed composite dry powder base material prepared in the first site into a wet mixing tank, add 20-30 parts of water, and stir for 10-15 minutes; Step 5: Add 3-5 parts of aluminum powder foaming activator to step 4, stir for 2-4 minutes to prepare slurry coal-based gasification slag composite multi-solid waste foundation pit base material, and pump it to the target foundation pit for landfill; Step 6: After the substrate is self-leveled and fixed into a horizontal surface, cover it with a curing film. The curing time is 72-96 hours.

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