Fluidized solidified soil based on large-particle waste residue and preparation method thereof

Abstract

The present invention discloses a method for preparing fluidized solidified soil based on large-particle waste residue. First, steel slag and tailings in a mass ratio of (2-3): (7-8) are uniformly stirred at high speed, and then water is added and stirred continuously to obtain a turbid liquid. Then, sodium silicate is slowly added to the turbid liquid under high-speed stirring to obtain a mixed liquid. A water reducer and a thickener are simultaneously added dropwise to the mixed liquid under stirring to obtain a mixture. Finally, a slump test is performed on the mixture. The amount of silica gel or water added is determined based on the test results to obtain fluidized solidified soil based on large-particle waste residue. This method improves the stirring and pumping performance of large-particle materials, reduces the risk of segregation, improves the homogeneity and stability of fluidized solidified soil, and reduces production costs. It also achieves the batch disposal of large amounts of solid waste and solves the problem of limited use of large-particle materials in traditional fluidized solidified soil.

Description

Technical Field

[0001] The present invention belongs to the field of environmental rock and soil technology, and particularly relates to a fluidized solidified soil based on large-particle waste residue and a preparation method thereof. Background Art

[0002] Globally, fluidized soil (FST) has attracted extensive attention and research as a building material with simple construction and excellent performance. Existing FSTs are primarily made from materials such as cement, lime, fly ash, and other reactive waste residues, and are suitable for projects such as backfilling, backfilling, and foundation treatment. However, conventional FSTs typically do not include large particles, primarily due to their poor mixing properties, difficulty in pumping, and tendency to segregate after filling. This limitation limits the large-scale application of bulk industrial solid wastes such as iron slag and steel slag. In China, the research and application of FSTs has gradually gained attention. Many studies have focused on optimizing the mix ratio of FSTs to improve their fluidity and stability. Cement and lime are widely used as the primary curing agents, but due to resource consumption and cost issues, a growing number of studies are focusing on alternative materials such as fly ash, slag powder, and other industrial by-products.

[0003] Existing research has largely focused on activating the activity of fine-powder waste residues, while the direct utilization of larger particles has been less studied. Some domestic research teams have experimented with using coarse-grained tailings or incompletely crushed industrial waste residues as aggregates to prepare fluidized soils, finding that under certain conditions, they can meet construction requirements. However, due to issues with mixing and pumping, their effectiveness in practical application remains to be further verified. Research on fluidized soils began earlier abroad, particularly in Europe and the United States. Foreign research institutions and companies have conducted extensive research on the material composition and process optimization of fluidized soils. Many studies focus on using industrial waste to replace traditional materials to reduce costs and minimize environmental impact. In Europe, some countries have made progress in utilizing steel slag and other industrial waste materials. Improvements in mixing equipment and processes have enhanced the pumping capacity of larger particles. Adjusting mix ratios and adding chemical additives have also successfully reduced segregation and stratification. Research in the United States has focused more on evaluating the performance of different waste residue materials. Through in-depth analysis of the physical and chemical properties of waste residue materials, suitable treatment methods for larger particles can be developed. For example, some research projects in the United States are dedicated to applying unground steel slag to fluidized soil, thereby reducing production costs and achieving rapid disposal of bulk waste.

[0004] Despite progress in the research of fluidized soils both domestically and internationally, the application of large-particle waste residues still faces numerous challenges. First, large-particle materials have poor mixing and pumping properties, leading to segregation and stratification during construction. Second, the uneven distribution of specific gravity and particle size of large-particle materials results in insufficient homogeneity and stability in fluidized soils. Furthermore, improving the overall performance of fluidized soils without increasing costs remains a pressing technical challenge. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for preparing fluidized solidified soil based on large-particle waste residue to address the problems in the existing fluidized solidified soil preparation technology, such as poor stirring effect and pumping effect of large particles and components with high specific gravity, easy segregation and stratification after filling, and poor homogeneity. The method can improve the stirring and pumping performance of large-particle materials, reduce the risk of segregation, improve the homogeneity and stability of fluidized solidified soil, and at the same time reduce production costs and realize the batch disposal of large amounts of solid waste.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0008] Step S1: stirring the steel slag and tailings at high speed, then adding water and continuing stirring to obtain a turbid liquid;

[0009] Step S2: slowly adding sodium silicate to the turbid liquid under high-speed stirring to obtain a mixed liquid;

[0010] Step S3: adding a water reducing agent and a thickener dropwise to the mixed solution while stirring to obtain a mixture;

[0011] Step S4: performing a slump test on the mixture, and determining the amount of silica gel or water to be added according to the slump test result to obtain a fluidized solidified soil based on large-particle waste residue.

[0012] Furthermore, in step S1, the mass ratio of steel slag to tailings is (2-3): (7-8).

[0013] Furthermore, in step S1, the particle size of the steel slag is 100-200 mesh, the tailings are iron tailings or copper tailings, and the tailings particle size is 150-250 mesh.

[0014] Furthermore, in step S1, the mass ratio of the added amount of water to the total mass of the steel slag and tailings is 5:1.

[0015] Furthermore, in steps S1 and S2, the high-speed stirring rate is 280-300 r / min.

[0016] Furthermore, in step S2, the modulus of the sodium silicate is 1.5 to 2, and the amount of sodium silicate added is 20% to 30% of the total mass of the steel slag and tailings.

[0017] Furthermore, in step S2, during the process of adding sodium silicate, it is observed whether there are large particles floating on the surface of the turbid liquid. If so, the rotation speed is reduced until it is reduced to 200 r / min.

[0018] Furthermore, in step S3, the water reducer is a polycarboxylate water reducer, and the thickener is guar gum.

[0019] Furthermore, in step S3, the amount of the water reducer and thickener added is 0.1% to 0.3% of the total mass of the steel slag and tailings.

[0020] Furthermore, in step S4, the method for determining the amount of silica gel or water to be added according to the slump test results is as follows: if the slump is within the range of 140 mm to 200 mm, no silica gel or water is needed; if the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements, and the amount of silica gel added is 1% to 3% of the total mass of the slag and tailings; if the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm.

[0021] The fluidized solidified soil based on large-particle waste residue is prepared by the above method.

[0022] Compared with the existing technology, the present invention has the following beneficial effects: the present invention provides a preparation method for fluidized solidified soil based on large-particle waste residue, which can make full use of large-particle industrial waste residue. Through innovative material ratios and preparation processes, the stirring and pumping performance of large-particle materials is improved, the risk of segregation is reduced, the homogeneity and stability of the fluidized solidified soil are improved, the permeability coefficient is reduced, the unconfined compressive strength is improved, and at the same time the production cost is reduced, the batch disposal of large amounts of solid waste is realized, and the problem of limited use of large-particle materials in traditional fluidized solidified soil is solved. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is described clearly and completely below with reference to specific embodiments. It should be noted that in the following embodiments and comparative examples, the steel slag used has a particle size of 150 mesh and is sourced from a mining area in Guizhou Province, and the tailings used are iron tailings with a particle size of 200 mesh and are sourced from the Lianyungang Port Area, but the present invention is not limited thereto.

[0024] In the following examples and comparative examples, the test method for the slump of fluidized solidified soil adopts the method in GB / T50080-2016 "Standard for Test Methods for Performance of Ordinary Concrete Mixtures"; the unconfined compressive strength and permeability coefficient tests adopt the method in GB / T50123-2019 "Standard for Geotechnical Test Methods".

[0025] Example 1

[0026] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0027] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0028] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0029] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0030] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0031] The fluidized solidified soil based on large-particle waste residue prepared in Example 1 was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 0.6 MPa, and the permeability coefficient was 8.6×10 -7 cm / s.

[0032] Comparative Example 1

[0033] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0034] Step S1: stirring the steel slag and tailings at a mass ratio of 1:9 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0035] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0036] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0037] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0038] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 0.3 MPa and 1.1×10 -6 cm / s.

[0039] Comparative Example 2

[0040] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0041] Step S1: stirring the steel slag and tailings at a mass ratio of 1:2 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0042] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0043] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0044] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0045] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 0.2 MPa and 1.2×10 -6 cm / s.

[0046] Example 2

[0047] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0048] Step S1: stirring the steel slag and tailings at a mass ratio of 2.5:7.5 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0049] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0050] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0051] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0052] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 1.4 MPa and 1.4×10 -7 cm / s.

[0053] Example 3

[0054] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0055] Step S1: Stir the steel slag and tailings at a mass ratio of 3:7 evenly at a stirring speed of 290 r / min, then add water and continue stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1 to obtain a turbid liquid.

[0056] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0057] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0058] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0059] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength of the sample was 0.8 MPa and the permeability coefficient was 4.7×10 -7 cm / s.

[0060] Example 4

[0061] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0062] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0063] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 30% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0064] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0065] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0066] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 1.8 MPa and 2.8×10 -7 cm / s.

[0067] Example 5

[0068] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0069] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0070] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 26% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0071] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0072] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0073] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of this sample was 1.4 MPa, and the permeability coefficient was 4.5×10 -7 cm / s.

[0074] Example 6

[0075] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0076] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0077] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 22% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0078] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.1% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0079] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0080] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 0.64 MPa and 7.9×10 -7 cm / s.

[0081] Example 7

[0082] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0083] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0084] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 26% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0085] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.2% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixed material;

[0086] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0087] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 1.1 MPa and 7.8×10 -7 cm / s.

[0088] Example 8

[0089] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0090] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0091] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0092] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.25% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixed material;

[0093] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0094] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days. The unconfined compressive strength and permeability coefficient of the sample were tested. The unconfined compressive strength and permeability coefficient of the sample were 2.4 MPa and 2.1×10 -7 cm / s.

[0095] Example 9

[0096] A method for preparing fluidized solidified soil based on large-particle waste residue comprises the following steps:

[0097] Step S1: stirring the steel slag and tailings at a mass ratio of 2:8 at a stirring speed of 290 r / min, then adding water and continuing stirring, wherein the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, to obtain a turbid liquid;

[0098] Step S2: Slowly adding sodium silicate with a modulus of 1.5 to the turbid liquid at a stirring speed of 290 r / min, wherein the mass of the added sodium silicate is 20% of the total mass of the steel slag and tailings, to obtain a mixed liquid; while observing whether there are large particles floating on the surface of the turbid liquid. If a large number of particles begin to float on the liquid surface, the speed can be reduced by one gear until it is reduced to 200 r / min;

[0099] Step S3: adding a polycarboxylate water reducer and a guar gum thickener dropwise to the mixed liquid at a stirring speed of 200 r / min, wherein the amount of the water reducer and the thickener added is 0.3% of the total mass of the steel slag and tailings, and observing whether the particles still float on the liquid surface to obtain a mixture;

[0100] Step S4: The mixture is subjected to a slump test. If the slump is within the range of 140 mm to 200 mm, no silica gel or water is required. If the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements. The amount of silica gel added is 1% to 3% of the total mass of the slag and tailings. If the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, water is continued to be added until the slump meets the requirements of 140 mm to 200 mm, thereby obtaining a fluidized solidified soil based on large-particle waste slag.

[0101] The prepared fluidized solidified soil based on large-particle waste residue was cured under standard curing conditions (relative humidity 95%, temperature 20°C) for 28 days, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of this sample was 1.6 MPa, and the permeability coefficient was 5.5×10 -7 cm / s.

Claims

1. A method for preparing fluidized solidified soil based on large-particle waste residue, characterized in that: The steps include: Step S1: stirring the steel slag and tailings at high speed, then adding water and continuing stirring to obtain a turbid liquid; Step S2: slowly adding sodium silicate to the turbid liquid under high-speed stirring to obtain a mixed liquid; Step S3: adding a water reducing agent and a thickener dropwise to the mixed solution while stirring to obtain a mixture; Step S4: performing a slump test on the mixture, and determining the amount of silica gel or water to be added based on the slump test result to obtain a fluidized solidified soil based on the large-particle waste residue; In step S1, the mass ratio of steel slag to tailings is (2-3): (7-8), the particle size of the steel slag is 100-200 mesh, and the tailings are iron tailings or copper tailings, and the tailings particle size is 150-250 mesh; In steps S1 and S2, the high-speed stirring rate is 280-300 r / min; In step S3, the water reducer is a polycarboxylate water reducer, and the thickener is guar gum.

2. The method for preparing fluidized solidified soil based on large-particle waste residue according to claim 1, characterized in that: In step S1, the mass ratio of the added amount of water to the total mass of the slag and tailings is 5:

1.

3. The method for preparing fluidized solidified soil based on large-particle waste residue according to claim 1, characterized in that: In step S2, the modulus of the sodium silicate is 1.5-2, and the amount of sodium silicate added is 20%-30% of the total mass of the steel slag and tailings.

4. The method for preparing fluidized solidified soil based on large-particle waste residue according to claim 1, characterized in that: In step S2, during the addition of sodium silicate, observe whether there are large particles floating on the surface of the turbid liquid. If so, reduce the rotation speed until it is reduced to 200 r / min.

5. The method for preparing fluidized solidified soil based on large-particle waste residue according to claim 1, characterized in that: In step S3, the amount of the water reducer and thickener added is 0.1% to 0.3% of the total mass of the slag and tailings.

6. The method for preparing fluidized solidified soil based on large-particle waste residue according to any one of claims 1 to 5, characterized in that: In step S4, the method for determining the amount of silica gel or water to be added according to the slump test result is as follows: if the slump is within the range of 140 mm to 200 mm, no silica gel or water is needed; if the slump is higher than the range of 140 mm to 200 mm, silica gel needs to be added until the slump meets the requirements, and the amount of silica gel added is 1% to 3% of the total mass of the slag and tailings; if the slump is lower than the range of 140 mm to 200 mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm.

7. Fluidized solidified soil based on large-particle waste residue obtained by the method according to any one of claims 1 to 6.