A method for combined lithium slag-carbide slag electroosmosis reinforcement of waste soil

Abstract

This invention relates to the field of resource utilization technology for waste soil and discloses a method for combined lithium slag and carbide slag electroosmosis reinforcement of waste soil. The method involves mixing lithium slag and carbide slag in a specific ratio with waste soil to form modified soil with low moisture content, which is then cured using an electroosmosis device to achieve rapid reinforcement and resource utilization of the waste soil.

Description

Technical Field

[0001] This invention relates to the field of resource utilization technology for waste slag, specifically to a method for combined electroosmosis reinforcement of waste slag using lithium slag and carbide slag. Background Technology

[0002] With the rapid development of industrial production, the amount of waste soil generated is increasing daily, making the effective treatment and utilization of this waste soil an urgent problem to be solved. Traditional waste soil treatment methods suffer from long processing cycles and low resource utilization rates. Lithium slag and calcium carbide slag are two common industrial wastes. Lithium slag mainly originates from waste generated during lithium battery production, while calcium carbide slag is generated during calcium carbide production. Both types of waste have large annual yields and contain a certain amount of active ingredients, making them suitable for reinforcing waste soil.

[0003] Meanwhile, electroosmosis technology has wide applications in various fields such as foundation reinforcement, dam stabilization, slope reinforcement, and sludge dewatering and remediation. It is particularly suitable for treating soft soils with high water content and low permeability, effectively accelerating soil drainage and improving soil strength and stability. However, currently, electroosmosis technology is mainly used to modify undisturbed soils with high water content, and it is difficult to implement on soils with low water content.

[0004] Therefore, using carbide slag and lithium slag to reinforce waste soil can turn waste into treasure and achieve resource utilization. If waste soil can be solidified by improving the electroosmosis device and combining it with electroosmosis technology, it will not only solve the problem that electroosmosis is difficult to apply in soil with low moisture content, but also greatly reduce the curing period, shorten the construction period, and improve construction efficiency in engineering projects. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a method for the combined electroosmotic reinforcement of waste soil using lithium slag and carbide slag. This method involves mixing lithium slag and carbide slag in a specific ratio with waste soil to form modified soil with low moisture content, which is then cured using an electroosmotic device to achieve rapid reinforcement and resource utilization of the waste soil.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A method for combined lithium slag-carbide slag electroosmosis reinforcement of waste slag includes the following steps: Step (1): Mix lithium slag and carbide slag to obtain lithium slag-carbide slag mixed solidification material; Step (2): Crush and screen the waste slag, and pass it through the sieve to obtain the pretreated waste slag; Step (3): Mix the pretreated waste slag with lithium slag-carbide slag mixed solidification material evenly, prepare a sample, and then perform electroosmotic curing. After curing, the solidified product is obtained.

[0007] Preferably, in step (1), the weight ratio of lithium slag to carbide slag is 1:1 to 3:1.

[0008] Preferably, in step (1): the particle size of the lithium slag is 0.01-1mm, the SiO2 content in the lithium slag is 60-70wt%, and the Al2O3 content is 15-30wt%.

[0009] Preferably, in step (1), the particle size of the carbide slag is 0.01-1 mm, and the Ca(OH)2 content in the carbide slag is 70-100 wt%.

[0010] Preferably, in step (2), the particle size of the pretreated waste soil is 0.01-5mm.

[0011] Preferably, in step (3), the weight ratio of the pretreated waste slag to the lithium slag-carbide slag mixed solidification material is 5:1 to 15:1.

[0012] Preferably, in step (3), the electroosmotic curing conditions are as follows: in the electroosmotic device, electroosmosis is carried out for 2-48 hours under the condition that the electric field strength is 1-15V / cm.

[0013] Furthermore, in step (3), the electroosmotic curing conditions are as follows: in the electroosmotic device, electroosmosis is carried out for 4-12 hours under the condition of electric field strength of 6-10V / cm.

[0014] Preferably, the solidified product is prepared by the method of combined electroosmosis reinforcement of waste soil using lithium slag and carbide slag as described above.

[0015] Preferably, an application of the cured product as described above in building materials.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention makes full use of two waste resources, lithium slag and carbide slag, reducing environmental pollution and realizing the resource utilization of waste. Moreover, no external chemical agents are required during the electroosmosis process, eliminating the risk of secondary pollution, and it belongs to a green and environmentally friendly treatment technology. Furthermore, it shortens the curing period and reduces the time cost of the project.

[0017] 2. This invention applies the electroosmosis method to the treatment of slag with low moisture content, and combines electroosmosis technology with industrial waste residue for the reinforcement of waste slag. This breaks through the limitation of traditional electroosmosis technology, which is only applicable to soft soil with high moisture content, and broadens the application of the electroosmosis method.

[0018] 3. This invention shortens the curing period of waste soil and improves reinforcement efficiency by using electroosmosis technology, while meeting the requirements of various performance indicators.

[0019] 4. The lithium slag used in this invention mainly comes from the waste residue generated during the lithium salt production process, while the calcium carbide slag is an industrial waste residue generated during the reaction of calcium carbide (CaC2) with water to produce acetylene. Both types of waste residue need to undergo pretreatment processes such as drying, crushing, and screening before use to control their particle size and ensure the uniformity and reactivity of the active ingredients. During the electroosmosis process, the active ingredients in the lithium slag and calcium carbide slag are excited under the action of an electric field to generate cementing substances such as hydrated calcium silicate (CSH), which significantly improves the strength and stability of the soil. At the same time, electroosmosis itself has the effect of drainage and consolidation, and the migration of water between electrodes increases the density of the soil sample. The prepared lithium slag-calcium carbide slag mixture and its reaction products can act as conductors during the electroosmosis process, with good conductivity, which improves the efficiency of electroosmosis and shortens the curing time.

[0020] 5. This invention utilizes industrial waste residue to replace traditional cement, lime and other solidification materials, significantly reducing material costs. The prepared solidified product has a compressive strength greater than 800 kPa, a plasticity index less than 15, and a moisture content that can be reduced by 30%. It can be widely used in the field of building materials, including but not limited to the production of bricks, paving materials and other building materials, and has good market prospects. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the electroosmosis device structure in the electroosmosis curing operation of the present invention; in the figure, 1 is a knob, 2 is a cover plate, and 3 is the main body base and support; Figure 2 This is a schematic diagram of the electroosmosis device structure in the electroosmosis curing operation of the present invention; in the figure, 1 is a knob, 2 is a cover plate, 3 is the main body base and support, 4 is a wire, and 5 is a soil sample; Figure 3 This is a working diagram of the electroosmosis device used in the electroosmosis curing operation of this invention; 1 in the diagram is an adjustable voltage DC power supply; Figure 4 This is a schematic diagram of the structure of the electrode plate in the electroosmosis device of the present invention; in the figure, 1 is the metal electrode plate, 2 is the cover plate, and 3 is the place where the wire is connected in the electrode plate; Figure 5 This is an X-ray diffraction pattern of the waste slag used in Embodiments 1 and 2 of the present invention. In the figure, Q represents quartz, H represents amphibole, and C represents calcite. Detailed Implementation

[0022] The present invention will be further illustrated below through specific embodiments. The following embodiments are specific implementations of the present invention, but the implementation of the present invention is not limited to the following embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and are included within the protection scope of the present invention.

[0023] Example 1 This embodiment discloses a method for combined lithium slag-carbide slag electroosmosis reinforcement of waste slag, including the following steps: Step (1): Mix lithium slag and carbide slag in a weight ratio of 2:1 to obtain lithium slag-carbide slag mixed solidification material; Step (2): Crush and screen the waste slag to remove large pieces of debris, and pass it through a 5mm sieve to obtain pre-treated waste slag with uniform particle size. Step (3): Mix the pretreated waste slag and lithium slag-carbide slag solidification material in a mixer at a weight ratio of 8:1 for 30 minutes to make a standard sample with a diameter of 39.1 mm and a height of 80 mm. Then, place it in an electroosmosis device and electroosmosis for 12 hours under an electric field strength of 10 V / cm for curing. After curing, the solidified product is obtained.

[0024] Example 2 This embodiment discloses a method for combined lithium slag-carbide slag electroosmosis reinforcement of waste slag, including the following steps: Step (1): Mix lithium slag and carbide slag in a weight ratio of 3:1 to obtain lithium slag-carbide slag mixed solidification material; Step (2): Crush and screen the waste slag to remove large pieces of debris, and pass it through a 5mm sieve to obtain pre-treated waste slag with uniform particle size. Step (3): Mix the pretreated waste slag and lithium slag-carbide slag solidification material in a mixer at a weight ratio of 10:1 for 30 minutes to make a standard sample with a diameter of 39.1 mm and a height of 80 mm. Then, place it in an electroosmosis device and electroosmosis for 4 hours under an electric field strength of 6 V / cm for curing. After curing, the solidified product is obtained.

[0025] In the above embodiments, the lithium slag has a particle size of 0.01-1 mm, a SiO2 content of 60-70 wt%, and an Al2O3 content of 15-30 wt%; the calcium carbide slag has a particle size of 0.01-1 mm, and a Ca(OH)2 content of 70-100 wt%. Figure 5 As shown, the main components of the waste soil are quartz, amphibole, and calcite.

[0026] Experimental data characterization and performance testing The performance of the cured products prepared in Examples 1-2 was tested, and the results are shown in Table 1. Table 1

[0027] The testing methods for each index in Table 1 are as follows: For liquid limit and plastic limit, the limit moisture content test was conducted on the carbonized soil sample according to the "Standard for Geotechnical Testing Methods" (GB / T 50123-2019) to determine the liquid limit and plastic limit; For unconfined compressive strength, the soil sample was prepared by the layered compaction method according to the "Standard for Geotechnical Testing Methods" (GB / T 50123-2019) to make a standard specimen with a diameter of 39.1 mm and a height of 80 mm. The compaction degree was controlled at 94% ± 2% by the total mass of the mixture. The strength test was also conducted according to the "Standard for Geotechnical Testing Methods" (GB / T 50123-2019).

[0028] As shown in Table 1, after electroosmotic curing, the plastic limit of the standard sample in Example 1 increased from 12% to 14%, and the liquid limit decreased from 30% to 24%, indicating gradual soil compaction. The unconfined compressive strength increased to 963 kPa after electroosmotic curing. Therefore, the electroosmotic curing product obtained in Example 1 can meet the requirements for use in secondary and lower-grade highway subgrades. After electroosmotic curing, the plastic limit of the standard sample in Example 2 increased from 12% to 13%, and the liquid limit decreased from 30% to 27%. The unconfined compressive strength increased to 867 kPa after electroosmotic curing. Therefore, the electroosmotic curing product obtained in Example 2 can be used for brick firing.

[0029] In summary, the properties of the solidified products prepared in Examples 1 and 2 of this invention are improved after electroosmosis treatment. Specifically, after electroosmosis treatment, the liquid limit of the solidified products decreases and the plastic limit increases. This is because the pretreated waste soil and the lithium slag-carbide slag mixed solidification material generate hydration products during the mixing reaction, which reduces the soil moisture and the free water content in the soil. The hydration products have a thicker bound water film, resulting in improved overall water stability and better plasticity. Meanwhile, the compressive strength of the solidified products increased after electroosmosis treatment. This is because before electroosmosis treatment, the geopolymer system composed of carbide slag and lithium slag underwent rapid hydration reaction, generating cementitious substances mainly composed of aluminosilicates. These cementitious substances have high strength, can bind soil particles, fill soil pores, and increase soil density, thus achieving an early increase in strength. During electroosmosis treatment, the electric current accelerated the migration of ions inside the soil sample, promoting hydration reaction and the generation of cementitious substances. Electroosmosis treatment also caused water inside the soil sample to migrate from the cathode to the anode and be discharged at the anode, greatly increasing the density of the anode. After electroosmosis, the anode of the soil sample is acidic, while the cathode is alkaline. Alkalinity can catalyze the geopolymer reaction, and the cathode strength also gradually increases, ultimately leading to a rapid increase in the overall strength of the soil sample within a few hours.

[0030] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for combined lithium slag-carbide slag electroosmosis reinforcement of waste slag, characterized in that, Includes the following steps: Step (1): Mix lithium slag and carbide slag to obtain lithium slag-carbide slag mixed solidification material; Step (2): Crush and screen the waste slag, and pass it through the sieve to obtain the pretreated waste slag; Step (3): Mix the pretreated waste slag with lithium slag-carbide slag mixed solidification material evenly, prepare a sample, and then perform electroosmotic curing. After curing, the solidified product is obtained.

2. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and calcium carbide slag according to claim 1, characterized in that, In step (1), the weight ratio of lithium slag to carbide slag is 1:1 to 3:

1.

3. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and calcium carbide slag according to claim 1, characterized in that, In step (1): the particle size of the lithium slag is 0.01-1mm, the SiO2 content in the lithium slag is 60-70wt%, and the Al2O3 content is 15-30wt%.

4. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and carbide slag according to claim 1, characterized in that, In step (1), the particle size of the carbide slag is 0.01-1 mm, and the Ca(OH)2 content in the carbide slag is 70-100 wt%.

5. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and calcium carbide slag according to claim 1, characterized in that, In step (2), the particle size of the pretreated waste soil is 0.01-5mm.

6. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag-carbide slag according to claim 1, characterized in that, In step (3), the weight ratio of the pretreated waste slag to the lithium slag-carbide slag mixed solidification material is 5:1 to 15:

1.

7. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and calcium carbide slag according to claim 1, characterized in that, In step (3), the electroosmotic curing conditions are as follows: in the electroosmotic device, electroosmosis is carried out for 2-48 hours under the condition that the electric field strength is 1-15V / cm.

8. The method for combined electroosmotic reinforcement of waste slag and soil using lithium slag and calcium carbide slag according to claim 1, characterized in that, In step (3), the electroosmotic curing conditions are as follows: in the electroosmotic device, electroosmosis is carried out for 4-12 hours under the condition that the electric field strength is 6-10V / cm.

9. A solidified product prepared by the method of combined electroosmosis reinforcement of waste slag and carbide slag as described in any one of claims 1-8.

10. An application of the cured product as described in claim 9 in building materials.

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