Method for preparing soft soil solidifying agent based on industrial waste residue regeneration and application thereof

Abstract

The application discloses a method for preparing a sludge soft soil curing agent based on regenerated industrial waste residues and application thereof, and belongs to the technical field of sludge curing, and is used for solving the technical problems that the sludge curing process, the sludge curing rate and the strength and erosion resistance of the cured sludge need to be further improved in the prior art, and specifically comprises the following steps: mixing industrial waste residues and carbide slag, ball milling, and passing through a 40-mesh screen to obtain a mixed powder; mixing the mixed powder and a sodium hydroxide solution; increasing the temperature of a reaction system to 50-60 DEG C; and stirring and dispersing for 2-3 hours; and adding a modifier to the reaction system. The sludge is cured by using the curing agent which is composed of the modified alkali-activated industrial waste residues, a cementing agent and a strengthening activator, so that the sludge curing rate is effectively improved, and the unconfined compressive strength and the erosion resistance of the cured sludge are also improved.

Description

Technical Field

[0001] This invention relates to the field of sludge solidification technology, specifically to a method for preparing sludge and soft soil solidification agents based on the regeneration of industrial waste residue and its application. Background Technology

[0002] With the rapid development of water conservancy projects, port construction, and river and lake management projects in my country, a large amount of silt with high water content is generated every year. The water content is usually between 60% and 90%. It has a loose structure, low strength, and poor bearing capacity. Moreover, the storage or disposal methods occupy a lot of land, are costly, and are prone to causing environmental pollution. Long-term storage not only occupies land resources, but may also cause risks such as heavy metal leaching and leachate seepage.

[0003] In the prior art, such as the invention patent with publication number CN102295442A, there is a material for solidifying marine dredging and tidal flat silt, which includes slag powder, fly ash, cement, calcium oxide, citric acid waste gypsum, lignin, activator and active deodorizer. It solves the problem of solidification and engineering utilization of marine dredging and tidal flat silt by adding the silt solidification material to the marine dredging and tidal flat silt through stirring. The marine dredging and tidal flat silt solidification material prepared by this invention makes full use of industrial and mining waste such as waste gypsum, slag and sawdust as fillers and additives for solidifying marine silt. While ensuring the mechanical properties, construction practicality and environmental protection of the marine silt solidification product, it also realizes the full and rational utilization of natural silt and industrial waste.

[0004] However, due to the low activity of industrial waste residue, the hydration reaction is slow under normal conditions, resulting in insufficient early strength development, which cannot meet the immediate needs of engineering. Furthermore, the curing agent is easily diluted in the sludge, and the reaction products are difficult to form a continuous network structure. Although some technologies have attempted to add water-absorbing materials, these materials often only solve the dehydration problem and have limited contribution to strength development. They may also interfere with the gelation reaction, resulting in the need to further improve the strength and erosion resistance of the sludge after solidification. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing silt and soft soil solidifying agent based on industrial waste residue recycling and its application, in order to solve the technical problem that the silt solidification process, silt solidification rate, and the strength and erosion resistance of solidified silt need to be further improved in the existing technology.

[0006] The objective of this invention can be achieved through the following technical solution: a method for preparing silt and soft soil solidifying agent based on industrial waste recycling, comprising the following steps: S1. After mixing industrial waste residue and carbide slag, the mixture is ball-milled and passed through a 40-mesh sieve to obtain a mixed powder; S2. Mix the mixed powder and sodium hydroxide solution, raise the temperature of the reaction system to 50-60℃, stir and disperse for 2-3 hours, add the modifier to the reaction system, keep the reaction at the temperature for 60-80 minutes, and then perform post-treatment to obtain industrial recycled slag. The synthesis reaction mechanism of industrial recycled slag is as follows: During the reaction, sodium hydroxide solution activates the slag powder, mineral powder, fly ash, etc. in the mixed powder, dissolving active SiO2, Al2O3 and other components, generating alkaline activated gels such as calcium silicate hydrate and sodium aluminum silicate hydrate. At the same time, after the KH-560 modifier is hydrolyzed, it undergoes chemical modification on the surface of the mixed powder particles, and the active groups such as epoxy groups and hydroxyl groups undergo ring-opening condensation, forming a surface coating modification on the mixed powder ions, thus preparing industrial recycled slag.

[0007] S3. Mix the industrial recycled slag, binder, and strengthening activator evenly to obtain the curing agent.

[0008] Furthermore, in step S1, the weight ratio of the industrial waste residue and the carbide slag is 7-8:1, wherein the industrial waste residue comprises the following components by weight: 50-60 parts of slag powder, 20-30 parts of waste gypsum, 30-40 parts of blast furnace slag, and 25-35 parts of fly ash.

[0009] Further, in step S2, the ratio of the mixed powder, sodium hydroxide solution, and modifier is 6-7g:15mL:1.8-2.2g, the concentration of the sodium hydroxide solution is 3-4mol / L, and the post-treatment includes: after the reaction is completed, spreading the reactants in an oven at a temperature of 70-80℃, drying to constant weight, pulverizing, and passing through a 40-mesh sieve to obtain industrial recycled slag; in step S3, the weight ratio of the industrial recycled slag, binder, and strengthening activator is 50-60:20-25:5-7.

[0010] Furthermore, in step S2, the modifier is composed of hyperbranched PEG, sodium lignosulfonate and KH-560 in a weight ratio of 7:3:2.

[0011] Furthermore, hyperbranched PEG is obtained by the following steps: A1. Mix polyethylene glycol, acrylic acid and catalyst, raise the temperature of the reaction system to 100-110℃, keep the reaction at this temperature for 6-8 hours, and then perform post-treatment to obtain unsaturated modified PEG. The synthesis reaction mechanism of unsaturated modified PEG is as follows:

[0012] During the reaction, concentrated sulfuric acid was used as a catalyst to catalyze the esterification reaction between the hydroxyl groups on the polyethylene glycol molecular chain and the carboxyl groups on the acrylic acid molecules, forming unsaturated double bonds on the polyethylene glycol molecular chain to prepare unsaturated modified PEG.

[0013] A2. Mix unsaturated modified PEG, sodium allyl sulfonate, 3-butenol, and purified water. Raise the temperature of the reaction system to 70-80℃, add initiator solution dropwise to the reaction system, keep the reaction at this temperature for 4-6 hours, and then perform post-treatment to obtain hyperbranched PEG.

[0014] The synthesis mechanism of hyperbranched PEG is as follows:

[0015]

[0016] During the reaction, the unsaturated olefin double bonds on the unsaturated modified PEG, sodium allyl sulfonate, and 3-butenol molecules undergo free radical polymerization under the action of free radical initiators to form long polyolefin chains. The double-terminal olefin double bonds on the unsaturated modified PEG molecular chains promote cross-linking between the long polyolefin chains, forming a hyperbranched cross-linked network.

[0017] Further, in step A1, the ratio of polyethylene glycol, acrylic acid, and catalyst is 8g:3g:0.5mL, the mass fraction of sulfuric acid is 90-98%, and the post-treatment includes: after the reaction is complete, the temperature of the reaction system is lowered to room temperature, 0.5mol / L sodium hydroxide solution is added to the reaction system to adjust the pH of the system to 7, the temperature of the reaction system is raised to 80℃, the negative pressure is drawn to 0.1MPa, and the low-boiling substances are removed by vacuum evaporation to obtain unsaturated modified PEG.

[0018] Further, in step A2, the ratio of unsaturated modified PEG, sodium allyl sulfonate, 3-butenol, purified water, and initiator solution is 13-15g:2-3g:1-2g:50mL:5mL. The initiator solution is composed of ammonium persulfate and purified water at a ratio of 1g:15mL. The post-treatment includes: after the reaction is complete, the reaction system is evaporated under reduced pressure to 0.1MPa to remove low-boiling substances, the reaction system temperature is lowered to room temperature, anhydrous ethanol is added to the reaction system, solid salts precipitate, the mixture is filtered, and the filtrate is transferred to a rotary evaporator with a water bath temperature of 70℃ to remove low-boiling substances under reduced pressure to obtain hyperbranched PEG.

[0019] Furthermore, in step S3, the preparation method of the binder is as follows: weigh out 10-12 parts of cement, 3-5 parts of lime, and 50-60 parts of phosphogypsum by weight and add them to a ball mill. After ball milling and mixing, pass the mixture through a 100-mesh sieve to obtain the binder.

[0020] Furthermore, in step S3, the strengthening activator is composed of sodium hydroxide and potassium humate in a weight ratio of 5:2. The application of silt and soft soil solidifying agent based on the regeneration of industrial waste residue involves adding 20-30% of the total mass of the silt and soft soil solidifying agent prepared by the method of regenerating industrial waste residue into the silt and soft soil of the port for silt solidification during port dredging.

[0021] The present invention has the following beneficial effects: 1. This invention involves preparing hyperbranched PEG containing sulfonic acid groups, hydroxyl groups, and ether bonds, and then mixing it with sodium lignosulfonate and KH-560 to encapsulate and modify the inorganic particles of the curing agent. This creates an "organic-inorganic" composite structure within the fine particles of the curing agent, improving interfacial compatibility. The organic coating layer provides steric hindrance and electrostatic repulsion, dispersing sludge particles and enhancing the permeability of the curing agent in the sludge. The binder, composed of cement, lime, and phosphogypsum, provides energy for the hydration reaction and acts as a cementing material. The reinforcing activator, composed of NaOH and potassium humate, activates the components in the industrial recycled slag and binder, accelerating the hydration reaction and firmly binding the sludge particles together. This accelerates sludge solidification and improves the overall strength and erosion resistance of the solidified sludge.

[0022] 2. This invention utilizes industrial waste residues rich in active silica and alumina, such as slag powder and fly ash, as raw materials. A hydration reaction occurs in an alkaline environment, generating products such as hydrated calcium silicate gel and ettringite. This reduces the internal porosity of the sludge, lowers the water permeation path, and improves the erosion resistance of the solidified sludge. The mixing of carbide slag with the industrial waste residue provides an additional calcium source, promoting the formation of ettringite during the hydration reaction and further enhancing the early strength of the solidified sludge. Sodium lignosulfonate acts as a dispersant to prevent particle agglomeration, ensuring the uniformity of the hydration reaction. Chelation can fix heavy metal ions and reduce environmental pollution. After hydrolysis, KH-560 coupling agent modifies the surface of inorganic particles, and then reacts with the hydroxyl groups on the surface of inorganic particles through epoxy groups to form chemical bonds, which enhances the organic-inorganic interface bonding force and reduces interface defects. The network structure of hyperbranched PEG and the dispersing effect of sodium lignosulfonate work together to ensure uniform distribution of industrial waste particles. At the same time, KH-560 strengthens the interface bonding to form an "organic-inorganic" composite reinforcement system, which further enhances the strength and erosion resistance of solidified sludge.

[0023] 3. This invention uses cement, lime, and phosphogypsum as a binder. Cement provides tricalcium silicate and dicalcium silicate, which hydrate to produce calcium silicate hydrate gel and ettringite, thus increasing strength. Lime raises the pH of the system, activates the pozzolanic activity of industrial waste, and promotes the hydration reaction. SO4²⁻ and Ca²⁺ in phosphogypsum react to form ettringite, accelerating early strength development and regulating the reaction rate. NaOH in the activator provides a strongly alkaline environment, promoting the deagglomeration of glass in slag and fly ash and accelerating the hydration reaction. Potassium humate dissolves metal ions through complexation, preventing their precipitation from interfering with the hydration process. Furthermore, the small molecular structure of potassium humate can penetrate into micropores, enhancing the hardening strength and erosion resistance of the solidified sludge. Detailed Implementation

[0024] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In this application, the slag powder is a granular material formed by water quenching and rapid cooling of molten slag, a by-product of blast furnace ironmaking, with a SiO2 content of 45-50%, an Al2O3 content of 18-22%, a CaO content of 25-28%, and a MgO content of 5-7%. In this application, the waste gypsum has a CaSO4·2H2O content higher than 85-90% and a P2O5 content lower than 1.5%. In this application, the blast furnace slag has a CaO content of 45-48%, a SiO2 content of 32-35%, an Al2O3 content of 5-9%, and a MgO content of 8-10%. In this application, fly ash is fine ash emitted by coal-fired power plants, which meets the requirements of GB / T 1596-2017 standard; In this application, the calcium carbide slag has a Ca(OH)2 content of 88-92%, a SiO2 content of 2.5-4%, and an Al2O3 content of 1.5-2%. In this application, the cement is ordinary Portland cement, type PO42.5; In this application, phosphogypsum is a byproduct generated during the production of phosphoric acid from the reaction of sulfuric acid with phosphate rock. The phosphogypsum contains 48-52% SO3, 0.5-0.8% P2O5, and 0.1-0.2% F⁻. In this application, polyethylene glycol is a commercially available product, model PEG1000; In this application, KH-560 is γ-glycidoxypropyltrimethoxysilane, CAS number 2530-83-8. Example 1

[0026] This embodiment provides a method for preparing a silt and soft soil solidification agent based on industrial waste recycling, including the following steps: Step 1: Preparation of hyperbranched PEG Weigh out 80g of polyethylene glycol, 30g of acrylic acid, and 5mL of 90wt% sulfuric acid and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 100℃. Keep the reaction at this temperature for 6 hours. Then, lower the temperature of the reaction flask to room temperature and add 0.5mol / L sodium hydroxide solution to adjust the pH of the system to 7. Raise the temperature of the reaction flask to 80℃ and apply a negative pressure of 0.1MPa to remove low-boiling substances by vacuum evaporation to obtain unsaturated modified PEG. Ammonium persulfate and purified water were mixed evenly at a ratio of 1g:15mL to obtain an initiator solution; Weigh out 130g of unsaturated modified PEG, 20g of sodium allyl sulfonate, 10g of 3-butenol, and 500mL of purified water and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 70℃. Add the initiator solution dropwise to the reaction flask and keep it at this temperature for 4 hours. Then, apply a negative pressure of 0.1MPa to the reaction flask and remove low-boiling substances by vacuum evaporation. Lower the temperature of the reaction flask to room temperature and add 1L of anhydrous ethanol to the reaction flask. Solid salts will precipitate out. Filter the mixture and transfer the filtrate to a rotary evaporator with a water bath temperature of 70℃. Remove low-boiling substances by vacuum evaporation to obtain hyperbranched PEG.

[0027] Step 2: Preparation of industrial recycled slag Weigh out the following by weight: 50 parts slag powder, 20 parts waste gypsum, 30 parts blast furnace slag, and 25 parts fly ash, and mix them to obtain industrial waste residue; Industrial waste residue and calcium carbide slag were added to a ball mill at a weight ratio of 7:1 and ball-milled, then passed through a 40-mesh sieve to obtain a mixed powder. Hyperbranched PEG, sodium lignosulfonate, and KH-560 were mixed evenly in a weight ratio of 7:3:2 to obtain the modifier; Weigh 600g of mixed powder and 1500mL of 3mol / L sodium hydroxide solution and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 50℃. Stir and disperse for 2 minutes. Add 180g of modifier to the reaction flask and keep it at the temperature for 60 minutes. Then, remove the reactants from the reaction flask and spread them in an oven at 70℃. Dry them to constant weight, pulverize them, and pass them through a 40-mesh sieve to obtain industrial recycled residue.

[0028] Step 3: Preparation of cementing agent and strengthening activator Weigh out the following by weight: 10 parts cement, 3 parts lime, and 50 parts phosphogypsum. Add them to a ball mill, mix them by ball milling, and then pass them through a 100-mesh sieve to obtain a binder. Weigh out 5 parts sodium hydroxide and 2 parts potassium humate by weight, mix them evenly, and obtain the strengthening activator.

[0029] Step 4: Prepare curing agent Weigh out 50 parts by weight of industrial recycled slag, 20 parts by weight of binder, and 5 parts by weight of strengthening activator, mix them evenly to obtain curing agent. Example 2

[0030] This embodiment provides a method for preparing a silt and soft soil solidification agent based on industrial waste recycling, including the following steps: Step 1: Preparation of hyperbranched PEG Weigh out 80g of polyethylene glycol, 30g of acrylic acid, and 5mL of 94wt% sulfuric acid and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 105℃. Keep the reaction at this temperature for 7 hours. Then, lower the temperature of the reaction flask to room temperature and add 0.5mol / L sodium hydroxide solution to adjust the pH of the system to 7. Raise the temperature of the reaction flask to 80℃ and apply a negative pressure of 0.1MPa to remove low-boiling substances by vacuum evaporation to obtain unsaturated modified PEG. Ammonium persulfate and purified water were mixed evenly at a ratio of 1g:15mL to obtain an initiator solution; Weigh out 140g of unsaturated modified PEG, 25g of sodium allyl sulfonate, 15g of 3-butenol, and 500mL of purified water and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 75℃. Add the initiator solution dropwise to the reaction flask and keep it at this temperature for 5 hours. Then, apply a negative pressure of 0.1MPa to the reaction flask and remove low-boiling substances by vacuum evaporation. Lower the temperature of the reaction flask to room temperature and add 1L of anhydrous ethanol to the reaction flask. Solid salts will precipitate out. Filter the mixture and transfer the filtrate to a rotary evaporator with a water bath temperature of 70℃. Remove low-boiling substances by vacuum evaporation to obtain hyperbranched PEG.

[0031] Step 2: Preparation of industrial recycled slag Weigh out the following by weight: 55 parts slag powder, 25 parts waste gypsum, 35 parts blast furnace slag, and 30 parts fly ash, mix them together to obtain industrial waste residue; Industrial waste residue and calcium carbide slag were added to a ball mill at a weight ratio of 7.5:1 and ball-milled. The mixture was then passed through a 40-mesh sieve to obtain a mixed powder. Hyperbranched PEG, sodium lignosulfonate, and KH-560 were mixed evenly in a weight ratio of 7:3:2 to obtain the modifier; Weigh out 650g of mixed powder and 1500mL of 3.5mol / L sodium hydroxide solution and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 55℃. Stir and disperse for 2.5h. Add 200g of modifier to the reaction flask and keep it at the temperature for 70min. Then remove the reactants from the reaction flask and spread them in an oven at 75℃. Dry them to constant weight, pulverize them, and pass them through a 40-mesh sieve to obtain industrial recycled residue.

[0032] Step 3: Preparation of cementing agent and strengthening activator Weigh out the following by weight: 11 parts cement, 4 parts lime, and 55 parts phosphogypsum. Add them to a ball mill, mix them by ball milling, and then pass them through a 100-mesh sieve to obtain a binder. Weigh out 5 parts sodium hydroxide and 2 parts potassium humate by weight, mix them evenly, and obtain the strengthening activator.

[0033] Step 4: Prepare curing agent Weigh out the following by weight: 55 parts of industrial recycled slag, 23 parts of binder, and 6 parts of strengthening activator, mix them evenly, and obtain the curing agent. Example 3

[0034] This embodiment provides a method for preparing a silt and soft soil solidification agent based on industrial waste recycling, including the following steps: Step 1: Preparation of hyperbranched PEG Weigh out 80g of polyethylene glycol, 30g of acrylic acid, and 5mL of 98wt% sulfuric acid and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 110℃. Keep the reaction at this temperature for 8 hours. Then, lower the temperature of the reaction flask to room temperature and add 0.5mol / L sodium hydroxide solution to adjust the pH of the system to 7. Raise the temperature of the reaction flask to 80℃ and apply a negative pressure of 0.1MPa to remove low-boiling substances by vacuum evaporation, thus obtaining unsaturated modified PEG. Ammonium persulfate and purified water were mixed evenly at a ratio of 1g:15mL to obtain an initiator solution; Weigh out 150g of unsaturated modified PEG, 30g of sodium allyl sulfonate, 20g of 3-butenol, and 500mL of purified water and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 80℃. Add the initiator solution dropwise to the reaction flask and keep it at this temperature for 6 hours. Then, apply a negative pressure of 0.1MPa to the reaction flask and remove low-boiling substances by vacuum evaporation. Lower the temperature of the reaction flask to room temperature and add 1L of anhydrous ethanol to the reaction flask. Solid salts will precipitate out. Filter the mixture and transfer the filtrate to a rotary evaporator at a water bath temperature of 70℃. Remove low-boiling substances by vacuum evaporation to obtain hyperbranched PEG.

[0035] Step 2: Preparation of industrial recycled slag Weigh out the following by weight: 60 parts slag powder, 30 parts waste gypsum, 40 parts blast furnace slag, and 35 parts fly ash, and mix them to obtain industrial waste residue; Industrial waste residue and calcium carbide slag were added to a ball mill at a weight ratio of 8:1 and ball-milled. The mixture was then passed through a 40-mesh sieve to obtain a mixed powder. Hyperbranched PEG, sodium lignosulfonate, and KH-560 were mixed evenly in a weight ratio of 7:3:2 to obtain the modifier; Weigh 700g of mixed powder and 1500mL of 4mol / L sodium hydroxide solution and add them to a reaction flask. Stir the mixture and raise the temperature of the reaction flask to 60℃. Stir and disperse for 3 hours. Add 220g of modifier to the reaction flask and keep it at the temperature for 80 minutes. Then, remove the reactants from the reaction flask and spread them in an oven at 80℃. Dry them to constant weight, pulverize them, and pass them through a 40-mesh sieve to obtain industrial recycled residue.

[0036] Step 3: Preparation of cementing agent and strengthening activator Weigh out the following by weight: 12 parts cement, 5 parts lime, and 60 parts phosphogypsum. Add them to a ball mill, mix them by ball milling, and then pass them through a 100-mesh sieve to obtain a binder. Weigh out 5 parts sodium hydroxide and 2 parts potassium humate by weight, mix them evenly, and obtain the strengthening activator.

[0037] Step 4: Prepare curing agent Weigh out the following by weight: 60 parts of industrial recycled slag, 25 parts of binder, and 7 parts of strengthening activator. Mix them evenly to obtain the curing agent. Example 4

[0038] This embodiment provides an application of a silt and soft soil solidifying agent prepared based on industrial waste residue recycling. The solidifying agent prepared in Example 1 is added to the port silt and soft soil at 20% of the total mass of silt. After mixing evenly, the mixture is solidified for 10 days at room temperature with a humidity of 90% to complete the solidification of the port dredging silt. The water content of the silt is 90%. Example 5

[0039] This embodiment provides an application of a silt and soft soil solidifying agent prepared based on industrial waste residue recycling. The solidifying agent prepared in Example 2 is added to the port silt and soft soil at 25% of the total mass of silt. After mixing evenly, the mixture is solidified for 10 days at room temperature with a humidity of 94% to complete the solidification of the port dredging silt. The water content of the silt is 75%. Example 6

[0040] This embodiment provides an application of a silt and soft soil solidifying agent prepared based on industrial waste residue recycling. The solidifying agent prepared in Example 3 is added to the port silt and soft soil at 30% of the total mass of silt. After mixing evenly, the mixture is solidified for 10 days at room temperature with a humidity of 98% to complete the solidification of the port dredging silt. The water content of the silt is 60%.

[0041] Comparative Example 1 The difference between this comparative example and Example 6 is that, in the preparation of the curing agent, in step 1, polyethylene glycol is used instead of unsaturated modified PEG to participate in the preparation of hyperbranched PEG.

[0042] Comparative Example 2 The difference between this comparative example and Example 6 is that KH-560 was not added in step 2 when preparing the curing agent.

[0043] Comparative Example 3 The difference between this comparative example and Example 6 is that, in step 2 of the preparation of the curing agent, carbide slag was not added.

[0044] Comparative Example 4 The difference between this comparative example and Example 6 is that no strengthening activator was added in step 4 during the preparation of the curing agent.

[0045] Performance testing: Referring to standard JTG 3441-2024 "Test Procedure for Inorganic Binder Stabilized Materials for Highway Engineering", the unconfined compressive strength and erosion resistance of the silt in Examples 4-6 and Comparative Examples 1-4 were determined on the 5th, 7th and 10th days after solidification. The specific test data are shown in Table 1 below.

[0046] Table 1 - Performance Test Data of Samples

[0047] Data Analysis: Comparative analysis of the data in Table 1 shows that the solidified sludge sample prepared by this invention achieved an unconfined compressive strength of 2.55 MPa and a scour loss rate of 1.32% on day 5, 2.69 MPa and 1.29% on day 7, and 2.75 MPa and 1.27% on day 10. All performance test data are superior to the comparative example, indicating that this invention, by modifying industrial waste residue through alkali activation and then combining it with a binder and a reinforcing activator to form a solidifying agent for sludge solidification, not only effectively improves the solidification rate of the sludge but also enhances the unconfined compressive strength and scour resistance of the solidified sludge.

[0048] The above description is merely an example and illustration of the structure of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the structure of the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A method for preparing silt and soft soil solidifying agent based on industrial waste recycling, characterized in that, Includes the following steps: S1. After mixing industrial waste residue and carbide slag, the mixture is ball-milled and passed through a 40-mesh sieve to obtain a mixed powder; S2. Mix the mixed powder and sodium hydroxide solution, raise the temperature of the reaction system to 50-60℃, stir and disperse for 2-3 hours, add the modifier to the reaction system, keep the reaction at the temperature for 60-80 minutes, and then perform post-treatment to obtain industrial recycled slag. S3. Mix the industrial recycled slag, binder, and strengthening activator evenly to obtain the curing agent.

2. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 1, characterized in that, In step S1, the weight ratio of the industrial waste residue and the carbide slag is 7-8:1, wherein the industrial waste residue comprises the following components by weight: 50-60 parts of slag powder, 20-30 parts of waste gypsum, 30-40 parts of blast furnace slag, and 25-35 parts of fly ash.

3. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 1, characterized in that, In step S2, the ratio of the mixed powder, sodium hydroxide solution, and modifier is 6-7g:15mL:1.8-2.2g, and the concentration of the sodium hydroxide solution is 3-4mol / L; in step S3, the weight ratio of the industrial recycled slag, binder, and strengthening activator is 50-60:20-25:5-7.

4. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 1, characterized in that, In step S2, the modifier is composed of hyperbranched PEG, sodium lignosulfonate and KH-560 in a weight ratio of 7:3:

2.

5. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 4, characterized in that, Hyperbranched PEG is obtained by the following steps: A1. Mix polyethylene glycol, acrylic acid and catalyst, raise the temperature of the reaction system to 100-110℃, keep the reaction at this temperature for 6-8 hours, and then perform post-treatment to obtain unsaturated modified PEG. A2. Mix unsaturated modified PEG, sodium allyl sulfonate, 3-butenol, and purified water. Raise the temperature of the reaction system to 70-80℃, add initiator solution dropwise to the reaction system, keep the reaction at this temperature for 4-6 hours, and then perform post-treatment to obtain hyperbranched PEG.

6. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 4, characterized in that, In step A1, the ratio of polyethylene glycol, acrylic acid, and catalyst is 8g:3g: 0.5 mL, wherein the sulfuric acid has a mass fraction of 90-98%.

7. The method for preparing silt and soft soil solidifying agent based on industrial waste recycling according to claim 4, characterized in that, In step A2, the ratio of unsaturated modified PEG, sodium allyl sulfonate, 3-butenol, purified water and initiator solution is 13-15g:2-3g:1-2g:50mL:5mL, and the initiator solution is composed of ammonium persulfate and purified water at a ratio of 1g:15mL.

8. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 1, characterized in that, In step S3, the cementitious agent is prepared by weighing 10-12 parts of cement, 3-5 parts of lime, and 50-60 parts of phosphogypsum by weight and adding them to a ball mill. After ball milling and mixing, the mixture is passed through a 100-mesh sieve to obtain the cementitious agent.

9. The method for preparing silt and soft soil solidification agent based on industrial waste recycling according to claim 1, characterized in that, In step S3, the strengthening activator is composed of sodium hydroxide and potassium humate in a weight ratio of 5:

2.

10. The application of a silt and soft soil solidification agent prepared from recycled industrial waste residue, characterized in that, The silt and soft soil solidifying agent prepared by the method of preparing silt and soft soil solidifying agent based on industrial waste residue regeneration as described in any one of claims 1-9 is added to port silt and soft soil at 20-30% of the total mass for silt solidification during port dredging.

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