Solid waste-based modified anti-seepage grouting material for solid waste stockpiling field in fracture zone area as well as preparation method and application of solid waste-based modified anti-seepage grouting material

Abstract

The invention discloses a solid waste-based modified anti-seepage grouting material for a solid waste stockpiling yard in a fracture zone area as well as a preparation method and application of the solid waste-based modified anti-seepage grouting material, and the anti-seepage grouting material is prepared from the following components in parts by weight: 10-50 parts of activated electrolytic manganese residues, 5-25 parts of a silicate composite cementing material, 1-15 parts of modified bentonite, 60-95 parts of sulphoaluminate cement and 90-150 parts of water. The anti-seepage grouting material disclosed by the invention has the characteristics of excellent operability, long-term anti-seepage performance and the like, can form a continuous and compact anti-seepage barrier for a long time, can continuously provide efficient physical and chemical barrier functions under complex geological conditions and variable environments, and realizes long-term protection on underground water and surrounding ecological environments.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial waste residue recycling and grouting materials, and in particular relates to a solid waste-based modified anti-seepage grouting material for a solid waste storage site in a broken zone area, and a preparation method and application thereof. Background Art

[0002] There are broken zones underground in karst areas, which are characterized by many cracks and pores, and can provide horizontal or vertical leakage paths for pollutants in solid waste storage sites, leading to increased risks of pollution to the surrounding environment and water sources. Grouting technology, as an effective pollution blocking measure, is widely used to control pollutant migration and improve risk management capabilities.

[0003] At present, grouting materials are mainly inorganic materials such as cement. In order to obtain excellent mechanical properties under high water-cement ratio, alkali activation or sulfate activation is often used. At present, the alkali-silicon reaction in alkali activation and the expansive gel in sulfate activation will cause the material to crack and deform, affecting the sealing effect. Secondly, under the influence of groundwater level fluctuations, rainfall and evaporation, grouting materials often face dry-wet cycles; at the same time, the complex environmental conditions of solid waste landfills, such as acidity, high salt concentration and high pollutant content, will also accelerate the deterioration of material performance, thereby greatly weakening its pollution barrier effect, making it difficult to play a long-term and stable role. Summary of the invention

[0004] In order to overcome the shortcomings of the above-mentioned prior art, the present invention provides a solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken zone areas, and a preparation method and application thereof. The anti-seepage grouting material has excellent anti-deterioration ability, good anti-seepage performance, and suitable setting time, and can effectively block the migration path of pollutants in karst solid waste sites for a long time to prevent leakage.

[0005] In order to achieve the above purpose, this application adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken zone areas, characterized in that it is composed of the following components in parts by weight: 10 to 50 parts of activated electrolytic manganese slag, 5 to 25 parts of silicate composite cementitious materials, 1 to 15 parts of modified bentonite, 60 to 95 parts of sulphoaluminate cement, and 90 to 150 parts of water.

[0007] In the above technical solution, the silicate composite cementitious material is one or a mixture of blast furnace slag powder, silica ash, volcanic ash, steel slag powder, and fly ash.

[0008] In the above technical scheme, the preparation method of the modified bentonite is: crushing and grinding the calcium-based bentonite; adding a sodium carbonate aqueous solution with a concentration of 2-5wt%; fully stirring and keeping it in a static state for maturation; crushing it after drying and screening it with a mesh screen.

[0009] In the above technical solution, the activated electrolytic manganese slag is the electrolytic manganese slag that is subjected to carbide slag deammoniation treatment, thermally activated at a temperature of 100 to 200° C., and mechanically ground by a ball mill.

[0010] In the above technical solution, the moisture content of the activated electrolytic manganese slag is less than 2%, and the main components are: SiO 2 22.03-30.52wt%, Al 2 O 3 2.37-7.82wt%, SO 3 11.33-29.59wt%, CaO 10.83-16.95wt%, Fe 2 O 3 5.63-7.16wt%, MnO 2.61-3.44wt%.

[0011] In a second aspect, the present invention provides a method for preparing a solid waste-based modified anti-seepage grouting material in a solid waste storage site in a broken zone area, comprising the following steps:

[0012] Step 1, weighing 10-50 parts of activated electrolytic manganese slag, 5-25 parts of silicate composite gelling material, and 1-15 parts of modified bentonite and stirring them fully in a stirrer;

[0013] Step 2: After the stirring is completed, 60 to 95 parts of sulphoaluminate cement and 90 to 150 parts of water are added in sequence and mixed thoroughly until the slurry is uniform and has no obvious particles, thereby obtaining the modified anti-seepage grouting material.

[0014] In the above technical solution, the silicate composite cementitious material is one or a mixture of blast furnace slag powder, silica ash, volcanic ash, steel slag powder, and fly ash.

[0015] In the above technical scheme, the preparation method of the modified bentonite is: crushing and grinding the calcium-based bentonite; adding a 2% to 5% sodium carbonate aqueous solution; fully stirring and keeping it in a static state for maturation; crushing it after drying and screening it with a mesh screen.

[0016] In the above technical solution, the moisture content of the activated electrolytic manganese slag is less than 2%, and the main components are (wt%): SiO 2 22.03-30.52, Al 2 O 3 2.37-7.82, SO3 11.33-29.59, CaO 10.83-16.95, Fe 2 O 3 5.63-7.16, MnO 2.61-3.44.

[0017] In a second aspect, the present invention provides the above-mentioned anti-seepage grouting material and the application of the anti-seepage grouting material prepared by the above-mentioned preparation method in long-term anti-seepage in solid waste dumps in karst fractured zones.

[0018] The activated electrolytic manganese slag selected by the present invention is deaminated by electrolytic stone, activated at 100-200°C, and mechanically activated, thereby effectively removing nitrogen compounds such as ammonia nitrogen in the electrolytic manganese slag, thereby improving the purity and environmental adaptability of the material; part of the crystal lattice is destroyed, increasing the proportion of amorphous and microcrystalline phases, having higher reaction activity, and being conducive to synergistic effects with other components; a large number of crystal defects and dislocations are introduced, thereby increasing the specific surface area and reaction active centers of the material.

[0019] The silicate composite gel material selected in the present invention can promote the formation of gel-state hydrated calcium silicate (CSH) under the stimulation of an appropriate amount of sulfate in electrolytic manganese slag, thereby improving the density and durability of the material, while blocking the invasion of external harmful substances and enhancing the long-term anti-seepage performance and chemical stability of the material.

[0020] The modified bentonite selected in the present invention has a high hydration effect, an enhanced swelling capacity and rapid self-healing under low-water conditions; the cation exchange capacity is greatly improved, and the adsorption of pollutants in the environment such as ammonia nitrogen and heavy metal ions is enhanced.

[0021] The present invention selects sulphoaluminate cement, which has the characteristics of rapid coagulation and hardening, and can ensure that the slurry completes initial coagulation in the complex hydraulic conditions in the karst area.

[0022] The preparation process used in the present invention is to first mix electrolytic manganese slag, silicate composite gelling material and modified bentonite, so that the sulfate in the electrolytic manganese slag can better activate the material through the mutual filling effect of particles; the distribution of the flexible material of the material is adjusted to ensure the flexibility of the material, which is conducive to self-healing under stress. The grouting material after sulfate activation has long-term impermeability and crack resistance.

[0023] The beneficial effects of the present invention are:

[0024] 1. The present invention forms an anti-seepage grouting material by activating electrolytic manganese slag, silicate composite cementitious material, modified bentonite, and sulphoaluminate cement. The material uses the activated electrolytic manganese slag as a sulfate activator and is applied to the grouting material. Under the stimulation of sulfate, an interaction is formed to accelerate the formation of calcium sulfonate to fill pores and increase the solid phase volume; promote multi-component synergistic reaction to generate gel-like hydration products to further optimize the microstructure of the material and improve the density of the material; change the interfacial chemical environment of the grouting material, promote the deposition and growth of hydration products on the surface of particles, enhance the interfacial bonding force between particles, and improve the anti-corrosion ability; at the same time, inhibit the occurrence of harmful reactions in cement and maintain the long-term stability and durability of the material.

[0025] 2. The anti-seepage grouting material of the present invention meets the anti-seepage grouting needs of solid waste storage sites in broken zones. The material contains solid waste electrolytic manganese slag, which reduces the amount of solid waste storage, reduces land resource occupation, promotes the recycling of resources, broadens the application field, and promotes green development.

[0026] 3. The anti-seepage grouting material of the present invention has excellent operability, long-term impermeability and other characteristics, and can form a continuous and dense anti-seepage barrier for a long time, ensuring that it can continue to provide efficient physical and chemical barrier functions under complex geological conditions and changing environments, thereby achieving long-term protection of groundwater and the surrounding ecological environment. DETAILED DESCRIPTION

[0027] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and the concept of the present invention will be fully conveyed to those skilled in the art, and the present invention will only be limited by the claims.

[0028] The raw materials used in the following embodiments of the present invention are:

[0029] Activated electrolytic manganese slag: After the electrolytic manganese slag is deaminated by carbide slag, it is thermally activated at a temperature of 100-200°C and mechanically ground by a ball mill. The alkalinity of carbide slag is used to release the ammonia nitrogen in the electrolytic manganese slag to prevent the slow release of ammonia nitrogen during use, which will cause pores in the material and environmental pollution. The moisture content of the activated electrolytic manganese slag is less than 2%. The main components are: SiO 2 22.03-30.52wt%, Al 2 O 3 2.37-7.82wt%, SO 3 11.33-29.59wt%, CaO10.83-16.95wt%, Fe 2 O 35.63-7.16wt%, MnO 2.61-3.44wt%. The activated electrolytic manganese slag is used as a sulfate activator to activate the activity of each admixture in the material, optimize the setting time of the grouting material, and ensure that the required requirements are met within a reasonable time.

[0030] Silicate composite cementitious material: a mixture of one or more of blast furnace slag powder, silica ash, volcanic ash, steel slag powder, and fly ash. The bulk density is 0.99g / cm 3 ~1.28g / cm 3 , density is 2.13g / cm 3 ~2.65g / cm 3 This density is conducive to the formation of gel-like substances and improves the long-term stability of the slurry.

[0031] Modified bentonite: crush and grind the calcium-based bentonite to 200 mesh; add 2% to 5% sodium carbonate aqueous solution; stir thoroughly and keep it in a static state for 24 hours; crush it after drying and screen it with a 325-mesh sieve.

[0032] Sulphoaluminate cement: specific surface area is 400-500m 2 / Kg, which is beneficial to improve the density and solidification rate of slurry.

[0033] Embodiment 1:

[0034] A solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken belt areas, comprising the following components in parts by weight:

[0035] 75 parts of sulphoaluminate cement, 5 parts of blast furnace slag powder, 15 parts of fly ash, 5 parts of modified bentonite, 30 parts of activated electrolytic manganese slag, and 120 parts of water.

[0036] The specific surface area of ​​sulphoaluminate cement is 410m 2 / Kg, the bulk density of fly ash is 1.12g / cm 3 , density 2.55g / cm 3 .

[0037] The components are uniformly mixed according to the mass ratio to form an anti-seepage grouting material.

[0038] Effect: The test was carried out in accordance with the national standard "Test Method for Cement Mortar Strength (ISO Method)" GB / T17671-2021. The initial setting time is 35 minutes and the final setting time is 87 minutes. After 28 days of curing, the compressive strength reaches 5.8MPa and the permeability coefficient is 3.65×10 - 8 cm / s. This indicates that the grouting material has high operability and mechanical properties and meets the requirements for anti-seepage in solid waste dumps.

[0039] After 28 days of standard curing, the material was subjected to 12 dry-wet cycles, with a dehydration treatment at 60 °C for 24 hours and a subsequent 24-hour wet treatment as one dry-wet cycle. The permeability coefficient was measured to be 9.67×10 -8 cm / s; indicating that the grouting material has strong long-term stability.

[0040] Embodiment 2:

[0041] A solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken belt areas, comprising the following components in parts by weight:

[0042] 90 parts of sulphoaluminate cement, 10 parts of blast furnace slag powder, 15 parts of volcanic ash, 5 parts of modified bentonite, 10 parts of activated electrolytic manganese slag, and 120 parts of water.

[0043] The specific surface area of ​​the selected sulphoaluminate cement is 410m 2 / Kg, the bulk density of fly ash is 1.12g / cm 3 , density 2.55g / cm 3 .

[0044] The components are uniformly mixed according to the mass ratio to form an anti-seepage grouting material.

[0045] Effect: The test was carried out in accordance with the national standard "Test Method for Cement Mortar Strength (ISO Method)" GB / T17671-2021. The initial setting time was 29 minutes and the final setting time was 67 minutes. After 28 days of curing, the compressive strength reached 4.96 MPa and the permeability coefficient was 4.23×10 - 8 cm / s. This indicates that the grouting material has high operability and mechanical properties and meets the requirements for anti-seepage in solid waste dumps.

[0046] After 28 days of standard curing, the material was subjected to 12 dry-wet cycles, with a dehydration treatment at 60°C for 24 hours and a subsequent 24-hour wet treatment as one dry-wet cycle. The permeability coefficient was measured to be 1.00×10 -7 cm / s; indicating that the grouting material has strong long-term stability.

[0047] Embodiment 3:

[0048] A solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken belt areas, comprising the following components in parts by weight:

[0049] 75 parts of sulphoaluminate cement, 5 parts of silica fume, 10 parts of steel slag powder, 5 parts of modified bentonite, 40 parts of activated electrolytic manganese slag, and 100 parts of water.

[0050] The specific surface area of ​​the selected sulphoaluminate cement is 410m 2 / Kg, the bulk density of fly ash is 1.12g / cm 3 , density 2.55g / cm 3 .

[0051] The components are uniformly mixed according to the mass ratio to form an anti-seepage grouting material.

[0052] Effect: The test was carried out in accordance with the national standard "Test Method for Cement Mortar Strength (ISO Method)" GB / T17671-2021. The initial setting time is 33 minutes and the final setting time is 70 minutes. After 28 days of curing, the compressive strength reaches 4.96Mpa and the permeability coefficient is 3.69×10 - 8 cm / s. This indicates that the grouting material has high operability and mechanical properties and meets the requirements for anti-seepage in solid waste dumps.

[0053] After 28 days of standard curing, the material was subjected to 12 dry-wet cycles, with a dehydration treatment at 60 °C for 24 hours and a subsequent 24-hour wet treatment as one dry-wet cycle. The permeability coefficient was measured to be 9.55×10 -8 cm / s; indicating that the grouting material has strong long-term stability.

[0054] Comparative Example:

[0055] An anti-seepage grouting material, composed of the following components in parts by weight:

[0056] 75 parts of sulphoaluminate cement, 5 parts of blast furnace slag powder, 15 parts of fly ash, 5 parts of modified bentonite, and 90 parts of water.

[0057] The specific surface area of ​​the selected sulphoaluminate cement is 410m 2 / Kg, the bulk density of fly ash is 1.12g / cm 3 , density 2.55g / cm 3 .

[0058] The components are uniformly mixed according to the mass ratio to form an anti-seepage grouting material.

[0059] Effect: The test was carried out in accordance with the national standard "Test Method for Cement Mortar Strength (ISO Method)" GB / T17671-2021. The initial setting time is 20 minutes and the final setting time is 45 minutes. After 28 days of curing, the compressive strength reaches 5.2MPa and the permeability coefficient is 5×10 -8 cm / s.

[0060] After 28 days of standard curing, the material was subjected to 12 dry-wet cycles, with a dehydration treatment at 60°C for 24 hours and a subsequent 24-hour wet treatment as one dry-wet cycle. The permeability coefficient was measured to be 1.72×10 -6 cm / s.

[0061] Compared with the embodiment, the comparative example of the present invention shows that the grouting material without adding electrolytic manganese slag has the problem of too short setting time and difficult construction operation, and exhibits extremely weak long-term anti-seepage performance after dry-wet cycle, and cannot be used for filling in the harsh environment of solid waste dumps in karst areas.

[0062] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A solid waste-based modified anti-seepage grouting material for solid waste storage sites in broken belt areas, characterized in that: The invention is composed of the following components in parts by weight: 10 to 50 parts of activated electrolytic manganese slag, 5 to 25 parts of silicate composite cementitious material, 1 to 15 parts of modified bentonite, 60 to 95 parts of sulphoaluminate cement and 90 to 150 parts of water.

2. The anti-seepage grouting material according to claim 1, characterized in that: The silicate composite cementitious material is one or a mixture of blast furnace slag powder, silica ash, volcanic ash, steel slag powder and fly ash.

3. The anti-seepage grouting material according to claim 1, characterized in that: The preparation method of the modified bentonite comprises: crushing and grinding the calcium-based bentonite; adding a sodium carbonate aqueous solution with a concentration of 2 to 5 wt%; fully stirring and keeping it in a static state for maturation; crushing it after drying, and screening it with a mesh screen.

4. The anti-seepage grouting material according to claim 1, characterized in that: The activated electrolytic manganese slag is electrolytic manganese slag that is subjected to carbide slag deammoniation treatment, thermally activated at a temperature of 100 to 200° C., and mechanically ground by a ball mill.

5. The anti-seepage grouting material according to claim 1, characterized in that: The activated electrolytic manganese slag has a moisture content of less than 2%, and its main components are: SiO2 22.03-30.52wt%, Al2O3 2.37-7.82wt%, SO3 11.33-29.59wt%, CaO 10.83-16.95wt%, Fe2O3 5.63-7.16wt%, and MnO 2.61-3.44wt%.

6. A method for preparing a solid waste-based modified anti-seepage grouting material for a solid waste storage site in a broken zone area, characterized in that: The following steps are involved: Step 1, weighing 10-50 parts of activated electrolytic manganese slag, 5-25 parts of silicate composite gelling material, and 1-15 parts of modified bentonite and stirring them fully in a stirrer; Step 2: After the stirring is completed, 60 to 95 parts of sulphoaluminate cement and 90 to 150 parts of water are added in sequence and mixed thoroughly until the slurry is uniform and has no obvious particles, thereby obtaining the modified anti-seepage grouting material.

7. The preparation method according to claim 1, characterized in that: The silicate composite cementitious material is one or a mixture of blast furnace slag powder, silica ash, volcanic ash, steel slag powder and fly ash.

8. The preparation method according to claim 1, characterized in that: The preparation method of the modified bentonite comprises: crushing and grinding the calcium-based bentonite; Adding a 2% to 5% sodium carbonate aqueous solution; stirring fully and keeping it in a static state for maturation; crushing it after drying and screening it with a mesh screen.

9. The preparation method according to claim 1, characterized in that: The activated electrolytic manganese slag has a moisture content of less than 2%, and its main components are: SiO2 22.03-30.52wt%, Al2O3 2.37-7.82wt%, SO3 11.33-29.59wt%, CaO 10.83-16.95wt%, Fe2O3 5.63-7.16wt%, and MnO 2.61-3.44wt%.

10. Application of the anti-seepage grouting material according to any one of claims 1 to 5 and the anti-seepage grouting material prepared by the preparation method according to any one of claims 6 to 9 in long-term anti-seepage in solid waste dumps in karst fractured zones.