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

Abstract

The preparation method comprises the following steps: uniformly stirring steel slag and tailings according to a mass ratio of (2-3): (7-8) at a high speed, adding water, continuously stirring to obtain a turbid solution, slowly adding sodium silicate into the turbid solution under high-speed stirring to obtain a mixed solution, simultaneously dropwise adding a water reducing agent and a thickening agent into the mixed solution under stirring, and uniformly stirring to obtain a slurry; and finally, carrying out a slump test on the mixture, and determining the addition amount of silica gel or water according to a test result, so as to obtain the flow-state solidified soil based on the large-particle waste residues. According to the method, through the innovative material ratio and preparation process, the stirring and pumping performance of the large-particle material is improved, the segregation risk is reduced, the homogeneity and stability of the fluid-state solidified soil are improved, meanwhile, the production cost is reduced, batch consumption of a large amount of solid waste is achieved, and the problem that use of the large-particle material in traditional fluid-state solidified soil is limited is solved.

Description

Technical Field

[0001] The 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 has received extensive attention and research as a building material with simple construction and excellent performance. Existing fluidized soil is mainly made of materials such as cement, lime, fly ash and other active waste slag, and is suitable for projects such as filling, backfilling and foundation treatment. However, the composition of traditional fluidized soil usually does not include large particles, which is mainly due to the poor mixing effect, difficulty in pumping and easy segregation of large particles after filling. This problem limits the large-scale application of bulk industrial solid waste such as iron slag and steel slag. In China, the research and application of fluidized soil has gradually received attention. Many studies have focused on how to optimize the mix ratio of fluidized soil to improve its fluidity and stability. Cement and lime are widely used as the main curing agents, but due to resource consumption and cost issues, more and more studies have begun to focus on alternative materials such as fly ash, slag powder and other industrial by-products.

[0003] Existing research focuses on the activation of fine powder waste slag, while there are few studies on the direct utilization of large-particle waste slag. Some domestic research teams have tried to use coarse-grained tailings sand or incompletely crushed industrial waste slag as aggregates to prepare fluidized solidified soil, and found that it can also meet construction requirements under certain conditions. However, due to the problems of mixing and pumping, the actual application effect needs to be further verified. In foreign countries, especially in Europe and the United States, the research on fluidized solidified soil started early. Foreign research institutions and enterprises have conducted a lot of research on the material composition and process optimization of fluidized solidified soil. Many studies focus on how to use industrial waste to replace traditional materials to reduce costs and reduce environmental impact. In Europe, some countries have made some progress in the use of steel slag and other industrial waste. They have improved the pumping capacity of large-particle materials by improving mixing equipment and processes. In addition, by adjusting the mix ratio and adding chemical additives, segregation and stratification phenomena have been successfully reduced. Research in the United States focuses more on the performance evaluation of different waste slag materials. Through in-depth analysis of the physical and chemical properties of waste slag materials, a suitable treatment method for large-particle waste slag is developed. For example, some research projects in the United States are dedicated to applying unground steel slag to fluidized soil consolidation, thereby reducing production costs and achieving rapid disposal of bulk waste.

[0004] Although some progress has been made in the research of fluidized solidified soil at home and abroad, the application of large-particle waste slag still faces many challenges. First, the mixing and pumping performance of large-particle materials is poor, which leads to segregation and stratification problems during construction. Secondly, due to the uneven distribution of specific gravity and particle size of large-particle materials, the homogeneity and stability of fluidized solidified soil are insufficient. In addition, how to improve the comprehensive performance of fluidized solidified soil without increasing costs is still a technical problem that needs to be solved urgently. 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, in order 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, and improve the homogeneity and stability of the fluidized solidified soil. At the same time, it can also 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 to obtain a turbid liquid; then adding water and continuing stirring.

[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 thickening agent to the mixed solution while stirring to obtain a mixed material;

[0011] Step S4: Perform a slump test on the mixture, determine the amount of silica gel or water to be added according to the slump test result, and 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 meshes, the tailings are iron tailings or copper tailings, and the particle size of the tailings is 150-250 meshes.

[0014] Furthermore, in step S1, the mass ratio of the amount of water added to the total mass of the 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 1.5-2, and the amount of sodium silicate added is 20%-30% of the total mass of the 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 reducing agent and thickener added is 0.1% to 0.3% of the total mass of the slag and tailings.

[0020] Further, in step S4, the method for determining the amount of silica gel or water to be added according to the slump test result is: if the slump is in the range of 140mm to 200mm, there is no need to add silica gel or water; if the slump is higher than the range of 140mm to 200mm, 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 140mm to 200mm, water accounting for 5% of the total mass of the slag and tailings is added, mixed evenly and tested again, and if it does not meet the standard, continue to add water until the slump meets the requirements of 140mm to 200mm.

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

[0022] Compared with the prior art, 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, improve the stirring and pumping performance of large-particle materials through innovative material ratios and preparation processes, reduce the risk of segregation, improve the homogeneity and stability of fluidized solidified soil, reduce the permeability coefficient, and improve the unconfined compressive strength. At the same time, it reduces production costs, realizes batch disposal of large amounts of solid waste, and solves the problem of limited use of large-particle materials in traditional fluidized solidified soil. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is clearly and completely described below in conjunction with specific embodiments. It should be noted that in the following embodiments and comparative examples, the steel slag particle size used is 150 mesh, which comes from a mining area in Guizhou, and the tailings used are iron tailings sand, the tailings particle size is 200 mesh, which comes from the Lianyungang port area, but it is not limited thereto.

[0024] In the following embodiments and comparative examples, the test method for the slump of fluidized solidified soil adopts the method in GB / T50080-2016 "Standard Test Method 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0030] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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 for 28 days under standard curing conditions (relative humidity 95%, temperature 20°C), and the unconfined compressive strength and permeability coefficient of the sample 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0037] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 0.3 MPa, and the permeability coefficient was 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 in 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0044] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 0.2 MPa, and the permeability coefficient was 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0051] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 1.4 MPa, and the permeability coefficient was 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 in a mass ratio of 3:7 evenly at a stirring speed of 290 r / min, then add water and continue stirring, the mass ratio of the added water to the total mass of the steel slag and tailings is 5:1, and a turbid liquid is obtained.

[0056] Step S2: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0058] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 30% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0065] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 1.8 MPa, and the permeability coefficient was 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 26% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0072] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 22% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.1% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0079] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 0.64 MPa, and the permeability coefficient was 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 26% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.2% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0086] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 1.1 MPa, and the permeability coefficient was 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.25% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0093] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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, and the unconfined compressive strength and permeability coefficient were tested. The unconfined compressive strength of the sample was 2.4 MPa, and the permeability coefficient was 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: at a stirring speed of 290 r / min, slowly add sodium silicate with a modulus of 1.5 to the turbid liquid, wherein the mass of the added sodium silicate is 20% of the total mass of the slag and the tailings, to obtain a mixed liquid; at the same time, observe 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: at a stirring speed of 200 r / min, a polycarboxylate water reducer and a guar gum thickener are simultaneously added dropwise to the mixed liquid, wherein the addition amount of the water reducer and the thickener is 0.3% of the total mass of the slag and tailings, and whether the particles are still floating on the liquid surface is observed to obtain a mixed material;

[0100] Step S4: Perform a slump test on the mixture. If the slump is within the range of 140 mm to 200 mm, there is no need to add silica gel or water. 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, add 5% of the total mass of the slag and tailings. After mixing evenly, test again. If it does not meet the standard, continue to add water until the slump meets the requirements of 140 mm to 200 mm, and obtain 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 to obtain a turbid liquid; then adding water and continuing stirring. 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 thickening agent to the mixed solution while stirring to obtain a mixed material; 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; In step S1, the mass ratio of steel slag to tailings is (2-3): (7-8); In steps S1 and S2, the high-speed stirring rate is 280-300 r / min.

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 S1, the particle size of the steel slag is 100-200 meshes, the tailings are iron tailings or copper tailings, and the particle size of the tailings is 150-250 meshes.

4. 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 slag and tailings.

5. 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 process of adding 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.

6. The method for preparing fluidized solidified soil based on large-particle waste residue according to claim 1, characterized in that: In step S3, the water reducing agent is a polycarboxylate water reducing agent, and the thickener is guar gum.

7. 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 reducing agent and thickener added is 0.1% to 0.3% of the total mass of the slag and tailings.

8. The method for preparing fluidized solidified soil based on large-particle waste residue according to any one of claims 1 to 7, 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, there is no need to add silica gel or water; 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, and 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.

9. Fluidized solidified soil based on large-particle waste residue obtained by the method according to any one of claims 1 to 8.