Marine facies sludge modifier and method for preparing barrier material by using marine facies sludge modifier

Abstract

The invention provides a marine facies sludge modifier and a method for preparing a barrier material by using the marine facies sludge modifier. The marine facies sludge modifier is prepared from industrial solid waste and active magnesium oxide, wherein the industrial solid waste comprises fly ash and lithium slag powder, and the mass of the industrial solid waste is not lower than 85% of the total mass of the marine silt. According to the invention, common industrial solid waste fly ash and lithium slag powder are taken as main raw materials, a certain content of active magnesium oxide is supplemented to excite the potential activity of the industrial solid waste, and the modifier and marine silt are doped and mixed, so that the modifier, the marine silt and the active magnesium oxide generate a large amount of hydrogel through chemical reaction; under the combined action of the substances, not only can the influence of organic matters and high salt content in the marine facies sludge on compressive strength and impermeability be reduced, but also the transformation of the marine facies sludge to a vertical antifouling barrier material with high compressive strength and high impermeability can be realized by improving chemical bonds, crystal phases and pore structures of a marine facies sludge material.

Description

Technical Field

[0001] The present invention relates to the field of environmental rock and soil technology, and in particular to a marine silt modifier and a method for preparing a barrier material using the same. Background Art

[0002] With the acceleration of my country's industrialization, the problem of waste slag dumps has become increasingly prominent. Waste slag dumps are often located near industrial plants, particularly power plants and other resource-extraction areas. Most power plants are located in coastal areas, which creates a risk of waste slag coming into contact with the marine environment. Therefore, to prevent waste slag from polluting the surrounding environment, the construction of effective vertical anti-pollution barriers is particularly important.

[0003] Since most of my country's power plants are located in coastal areas, the waste slag they produce is piled up in nearby coastal areas. Therefore, the marine silt content around the storage yard is rich. However, traditional sludge improvers such as concrete and bentonite cannot effectively improve the marine silt, and the improved marine silt materials cannot serve as an anti-fouling barrier.

[0004] Based on this, there is an urgent need to provide a marine silt modifier and a method for preparing a barrier material using the same. Summary of the Invention

[0005] The embodiments of the present invention provide a marine sludge improver and a method for preparing a barrier material using the same, which can solve the problem that traditional sludge improvers cannot effectively improve marine sludge and the improved marine sludge material cannot serve as an anti-fouling barrier.

[0006] In a first aspect, the present invention provides a marine sludge modifier, which is composed of industrial solid waste and activated magnesium oxide; wherein the industrial solid waste includes fly ash and lithium slag powder, and the mass of the industrial solid waste is not less than 85% of the total mass of the marine sludge.

[0007] Preferably, the fly ash comprises the following components in percentage by mass: SiO2 is 45% to 55%, Al2O3 is 35% to 45%, and the content of free CaO is not more than 5%.

[0008] Preferably, the lithium slag powder comprises the following components in percentage by mass: 40% to 50% CaO, 20% to 30% SiO2, and 10% to 20% Al2O3.

[0009] Preferably, the particle size of the fly ash and the lithium slag powder are both 0.1-100 μm.

[0010] Preferably, the following components are included, calculated by mass: 30-70 parts of fly ash, 30-70 parts of lithium slag powder and 10-15 parts of active magnesium oxide.

[0011] Preferably, the mass ratio of the fly ash to the lithium slag powder is 7:(3-5).

[0012] In a second aspect, the present invention provides a method for preparing a barrier material using the marine silt modifier described in any one of the first aspects above, the preparation method comprising the following steps:

[0013] (1) adding fly ash, lithium slag powder and activated magnesium oxide into water in proportion and mixing them to obtain a modifier slurry;

[0014] (2) The improver slurry is stirred and mixed with the marine silt, and molded using a mold to obtain the barrier material.

[0015] Preferably, in step (1), the ratio of the total mass of fly ash, lithium slag powder and activated magnesium oxide to the mass of water is (0.4-0.5):1.

[0016] Preferably, in step (2), the moisture content of the marine sludge is 2 to 2.5 times its liquid limit.

[0017] Preferably, in step (2), the mass of the improver slurry accounts for 20-40% of the mass of the marine silt.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects:

[0019] (1) In the present invention, common industrial solid waste fly ash and lithium slag powder are used as the main raw materials, and a certain amount of active magnesium oxide is added to stimulate the potential activity of the above industrial solid waste. During the mixing process of the above modifiers with marine silt, the three produce a large amount of hydrogel through chemical reaction. The combined action of the above substances can not only reduce the impact of organic matter and high salt content in marine silt on compressive strength and impermeability, but also realize the transformation of marine silt into a vertical anti-fouling barrier material with high compressive strength and high impermeability by improving the chemical bonds, crystal phase and pore structure of the marine silt material.

[0020] (2) The marine sludge improver of the present invention uses simple and low-cost raw materials, including solid wastes such as fly ash and lithium slag powder. It not only realizes the recycling of industrial solid waste, but also effectively improves the properties of marine sludge by using the sludge improver prepared therefrom, realizes the large-scale resource utilization of marine sludge, and produces good environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 This is a flow chart of a method for preparing a barrier material using a marine silt modifier provided in Example 1 of the present invention. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0024] Traditional sludge conditioners are generally based on concrete, bentonite, cement and lime, which can be mixed with water-containing sludge to solidify to form a barrier material with a certain strength. However, unlike traditional water-containing sludge, marine sludge has the characteristics of high water content, high salt content, high organic matter and low bearing capacity. During the improvement process, due to the influence of the salt content and organic matter in the marine silt, traditional sludge conditioners are not suitable for marine silt. After using them to improve marine silt, they cannot form an anti-fouling barrier material that meets the barrier function.

[0025] Therefore, in the embodiment of the present invention, from the perspective of realizing the resource recycling of industrial solid waste and marine silt, by using local materials, fly ash and lithium slag powder, which are common solid waste materials in coastal areas, are used as the main raw materials, and supplemented with a certain amount of active magnesium oxide to improve the marine silt together, so that it meets the requirements of the vertical anti-pollution barrier and forms an efficient silt barrier soil material; in this way, the transportation and procurement costs of the materials can be reduced, and the silt barrier soil material with excellent performance is prepared by improving the marine silt, which is of great significance to the current coastal waste slag yards.

[0026] Based on this, an embodiment of the present invention provides a marine sludge modifier, which is composed of industrial solid waste and activated magnesium oxide; wherein the industrial solid waste includes fly ash and lithium slag powder, and the mass of the industrial solid waste is not less than 85% of the total mass of the marine sludge (for example, it can be 85%, 90% or 95%).

[0027] In an embodiment of the present invention, common industrial solid waste fly ash and lithium slag powder are used as the main raw materials, and a certain amount of active magnesium oxide is added to stimulate the potential activity of the above-mentioned industrial solid waste. During the process of doping and mixing the above-mentioned modifiers with marine silt, the three produce a large amount of hydrogel through chemical reaction. The combined action of the above-mentioned substances can not only reduce the impact of organic matter and high salt content in marine silt on compressive strength and impermeability, but also can realize the transformation of marine silt into a vertical anti-fouling barrier material with high compressive strength and high impermeability by improving the chemical bonds, crystal phases and pore structures of the marine silt materials.

[0028] According to some preferred embodiments, the fly ash comprises the following components, in mass percentage: SiO2 is 45% to 55% (for example, it can be 45%, 48%, 50%, 52% or 55%), Al2O3 is 35% to 45% (for example, it can be 35%, 38%, 40%, 42% or 45%), and the content of free CaO is not more than 5%.

[0029] According to some preferred embodiments, the lithium slag powder comprises the following components, in mass percentage: CaO is 40% to 50% (for example, it can be 45%, 48%, 50%, 52% or 55%), SiO2 is 20% to 30% (for example, it can be 45%, 48%, 50%, 52% or 55%), and Al2O3 is 10% to 20% (for example, it can be 45%, 48%, 50%, 52% or 55%).

[0030] In the embodiment of the present invention, the fly ash used is untreated first-level fly ash produced by a power plant, and does not require drying or grinding. The lithium slag powder is the waste slag discharged by calcining spodumene ore at a high temperature of 1200°C during the production of lithium carbonate. The two are mixed and used directly without pretreatment, which simplifies the production process. The main active ingredients in the fly ash are SiO2 and Al2O3, which can provide rich Al and Si components. The main active ingredients in the lithium slag powder are CaO, SiO2 and Al2O3. After mixing, the two can complement each other. The active substances in the fly ash and lithium slag powder are stimulated by active magnesium oxide to form a geogel polymer. Moreover, under the joint action of the above substances, not only can the effects of organic matter and high salt content in marine silt on the improvement process of marine silt be effectively reduced, but it can also be converted into an anti-fouling barrier material with good compressive strength and impermeability.

[0031] It should be noted that, in the embodiments of the present invention, fly ash and lithium slag powder inevitably include other components. Considering that the components are mainly used as effective ingredients in the improvement process of marine sludge, the other components have little effect on the improvement process, so they are not described in detail in the embodiments of the present invention.

[0032] According to some preferred embodiments, the particle size of the fly ash and the lithium slag powder are both 0.1-100 μm.

[0033] In the embodiment of the present invention, both fly ash and lithium slag powder are untreated primary solid waste powder separated by a grading system in industry, which is conducive to ensuring better subsequent reaction activity and process performance.

[0034] According to some preferred embodiments, the following components are included, in parts by mass: 30 to 70 parts of fly ash (for example, 30 parts, 40 parts, 50 parts, 60 parts or 70 parts), 30 to 70 parts of lithium slag powder (for example, 30 parts, 40 parts, 50 parts, 60 parts or 70 parts) and 10 to 15 parts of activated magnesium oxide (for example, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts or 15 parts).

[0035] According to some preferred embodiments, the mass ratio of the fly ash to the lithium slag powder is 7:(3-5) (for example, it can be 7:3, 7:4 or 7:5).

[0036] In the embodiments of the present invention, fly ash is used as the primary raw material, along with a certain amount of lithium slag powder, and activated magnesium oxide is used to stimulate the activity of the two, thereby enabling a chemical reaction between the three to form a large amount of polymer hydrogel. The formation of the polymer hydrogel not only increases the adhesion between the marine silt components but also significantly improves the chemical bonds, crystal phase, and pore structure of the marine silt. Unlike activators such as sodium hydroxide or sodium silicate, which are prone to insufficient alkalinity in the later stages, resulting in slow strength growth, the embodiments of the present invention use activated magnesium oxide to stimulate the activity of fly ash and lithium slag powder. Magnesium oxide has a relatively low solubility and can slowly release hydroxide ions, thereby continuously increasing the strength of the marine silt-solidified soil. In addition, the magnesium oxide produced by hydration will expand early to counteract the shrinkage of the marine silt-solidified soil. At the same time, in highly saline marine silt, magnesium oxide can stimulate the production of magnesium-containing gel, which is salt-tolerant and can resist salt erosion.

[0037] Furthermore, in an embodiment of the present invention, by synergistically controlling the contents of fly ash, lithium slag powder and active magnesium oxide, the marine silt can be transformed into an anti-fouling barrier material, and is conducive to ensuring the anti-fouling barrier material has better compressive strength and impermeability. Experiments of the present invention have confirmed that if the fly ash content is too high, it is not conducive to ensuring the good mechanical strength of the anti-fouling barrier material. The addition of an appropriate content of lithium slag powder is conducive to releasing active components under the stimulation of magnesium oxide to react with the active components in the fly ash to form a polymer hydrogel, thereby further enhancing the mechanical strength of the anti-fouling barrier material. However, if the content of lithium slag powder is too high, it may lead to a decrease in impermeability. At the same time, an appropriate content of active magnesium oxide is conducive to achieving continuous stimulation of the active components in fly ash and lithium slag powder to ensure the anti-fouling barrier material has better mechanical properties and impermeability, but if the content of active magnesium oxide is too high, it will increase the cost.

[0038] like Figure 1 As shown, the present invention also provides a method for preparing a barrier material with the marine silt modifier described in any one of the above, and the preparation method comprises the following steps:

[0039] (1) adding fly ash, lithium slag powder and activated magnesium oxide into water in proportion and mixing them to obtain a modifier slurry;

[0040] (2) The improver slurry is stirred and mixed with the marine silt, and molded using a mold to obtain the barrier material.

[0041] According to some preferred embodiments, in step (1), the ratio of the total mass of fly ash, lithium slag powder and activated magnesium oxide to the mass of water is (0.4-0.5):1 (for example, it can be 0.4:1, 0.45:1 or 0.5:1).

[0042] In an embodiment of the present invention, in the process of improving marine silt using the above-mentioned marine silt improver, the above-mentioned raw materials are first added to water in proportion and mixed to form an improver slurry with a certain mass concentration. The improver slurry is stirred and mixed with the marine silt and added to a mold for solidification and shaping, which is conducive to sufficient contact between the components in the improver slurry and the marine silt, thereby realizing the transformation of the marine silt into an anti-fouling barrier material with high impermeability and mechanical strength.

[0043] It should be noted that, in the embodiment of the present invention, the stirring speeds in step (1) and step (2) can be adjusted according to actual needs. For example, the stirring rate in step (1) can be 30-40 r / min, and the stirring time is 3-5 min; in step (2), for example, a small planetary mixer can be used for uniform stirring for 5-10 min.

[0044] According to some preferred embodiments, in step (2), the water content of the marine sludge is 2 to 2.5 times (for example, 2 times, 2.2 times or 2.5 times) its liquid limit.

[0045] According to some preferred embodiments, in step (2), the mass of the modifier slurry accounts for 20% to 40% (for example, 20%, 30% or 40%) of the mass of the marine silt.

[0046] In an embodiment of the present invention, the above-mentioned marine silt improvement is used to treat marine silt with a water content of more than 2 times its liquid limit. The marine silt has a high water content and almost zero bearing capacity, and the salt content of the marine silt is 11.3% and the organic matter content is 13.2%. By adding a small amount of marine silt improver into the above-mentioned marine silt, the properties of the marine silt can be effectively improved, and an anti-fouling barrier material that meets the performance requirements of vertical barriers in coastal areas and has excellent anti-seepage performance is obtained. The anti-fouling barrier material meets the construction requirements of vertical anti-fouling barriers and can realize large-scale resource utilization of marine silt; moreover, the raw materials used in the silt improver are simple in type and low in cost, including solid wastes such as fly ash and lithium slag powder, and waste-to-waste treatment is achieved without relying on traditional cement or quicklime, thereby producing good environmental benefits. The improver has the advantages of low carbon emissions, low cost and easy operation.

[0047] In order to more clearly illustrate the technical solutions and advantages of the present invention, a marine sludge modifier and a method for preparing a barrier material using the same are described in detail below through the following examples; in the following examples, the fly ash is the first-grade fly ash produced by the power plant that has not been dried, and its main components and mass percentages are as follows: SiO2 59.97%, Al2O3 20.35%, Fe2O3 7.04%; the main components and mass percentages of the lithium slag powder are as follows: CaO 43.17%, SiO2 27.75%, Al2O3 14.85%; the active magnesium oxide is active magnesium oxide with a purity of 90% and an activity of 70; the content of each component is expressed in parts by mass.

[0048] Example 1:

[0049] (1) Add 70 parts of fly ash, 30 parts of lithium slag powder and 10 parts of activated magnesium oxide to 50 parts of water in proportion and stir at 40 r / min for 4 minutes to obtain a modifier slurry;

[0050] (2) adding clean water to the in-situ marine silt with a moisture content of 35% to 50% to adjust its moisture content to 2 to 2.5 times the liquid limit until its moisture content reaches 90%;

[0051] The improver slurry and 500 parts of marine silt were added to a small star mixer and stirred at 30 r / min for 5 minutes to mix. The stirred improved silt was then loaded into a mold in three layers and vibrated thoroughly to make the improved silt in the mold dense to obtain a barrier material.

[0052] Example 2:

[0053] (1) Add 70 parts of fly ash, 30 parts of lithium slag powder and 10 parts of activated magnesium oxide to 50 parts of water in proportion and stir at 30 r / min for 5 minutes to obtain a modifier slurry;

[0054] (2) adding clean water to the in-situ marine silt with a moisture content of 35% to 50% to adjust its moisture content to 2 to 2.5 times the liquid limit until its moisture content reaches 90%;

[0055] The improver slurry and 640 parts of marine silt were added to a small star mixer and stirred at 30 r / min for 5 minutes to mix. The stirred improved silt was then loaded into a mold in three layers and vibrated thoroughly to make the improved silt in the mold dense to obtain a barrier material.

[0056] Example 3:

[0057] (1) Add 70 parts of fly ash, 30 parts of lithium slag powder and 10 parts of activated magnesium oxide to 50 parts of water in proportion and stir at 40 r / min for 4 minutes to obtain a modifier slurry;

[0058] (2) adding clean water to the in-situ marine silt with a moisture content of 35% to 50% to adjust its moisture content to 2 to 2.5 times the liquid limit until its moisture content reaches 90%;

[0059] The improver slurry and 950 parts of marine silt were added to a small star mixer and stirred at 30 r / min for 5 minutes to mix. The stirred improved silt was then loaded into a mold in three layers and vibrated thoroughly to make the improved silt in the mold dense to obtain a barrier material.

[0060] Example 4:

[0061] Example 4 is basically the same as Example 1, except that: in step (1), the improver slurry contains 60 parts of fly ash, 40 parts of lithium slag powder, 10 parts of active magnesium oxide, and 50 parts of water.

[0062] Example 5:

[0063] Example 5 is basically the same as Example 1, except that: in step (1), the improver slurry contains 60 parts of fly ash, 40 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 640 parts of marine sludge with a moisture content of 90% are used.

[0064] Example 6

[0065] Example 6 is basically the same as Example 1, except that: in step (1), the improver slurry contains 60 parts of fly ash, 40 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 950 parts of marine silt with a moisture content of 90%.

[0066] Example 7

[0067] Example 7 is basically the same as Example 1, except that: in step (1), the improver slurry contains 50 parts of fly ash, 50 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 500 parts of marine silt with a moisture content of 90%.

[0068] Example 8

[0069] Example 8 is basically the same as Example 1, except that: in step (1), the improver slurry contains 50 parts of fly ash, 50 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 640 parts of marine silt with a moisture content of 90% are used.

[0070] Example 9

[0071] Example 9 is basically the same as Example 1, except that: in step (1), the improver slurry contains 50 parts of fly ash, 50 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 950 parts of marine silt with a moisture content of 90%.

[0072] Example 10

[0073] Example 10 is basically the same as Example 1, except that: in step (1), the improver slurry contains 40 parts of fly ash, 60 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 500 parts of marine sludge with a moisture content of 90%.

[0074] Example 11

[0075] Example 11 is basically the same as Example 1, except that: in step (1), the improver slurry contains 40 parts of fly ash, 60 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 640 parts of marine sludge with a moisture content of 90%.

[0076] Example 12

[0077] Example 12 is basically the same as Example 1, except that: in step (1), the improver slurry contains 40 parts of fly ash, 60 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 950 parts of marine silt with a moisture content of 90%.

[0078] Example 13

[0079] Example 13 is basically the same as Example 1, except that: in step (1), the improver slurry contains 30 parts of fly ash, 70 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 500 parts of marine sludge with a moisture content of 90%.

[0080] Example 14

[0081] Example 14 is basically the same as Example 1, except that: in step (1), the improver slurry contains 30 parts of fly ash, 70 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 640 parts of marine sludge with a moisture content of 90%.

[0082] Example 15

[0083] Example 15 is basically the same as Example 1, except that: in step (1), the improver slurry contains 30 parts of fly ash, 70 parts of lithium slag powder, 10 parts of activated magnesium oxide, and 50 parts of water; in step (2), 950 parts of marine sludge with a moisture content of 90%.

[0084] Comparative Example 1

[0085] (1) Add 390 parts of fly ash and 23.40 parts of quicklime to 248.04 parts of water and stir at 40 rpm for 4 minutes to obtain a modifier slurry;

[0086] (2) adding clean water to the in-situ marine silt with a moisture content of 35% to 50% to adjust its moisture content to 2 to 2.5 times the liquid limit until its moisture content reaches 90%;

[0087] The improver slurry and 413.4 parts of marine silt were added to a small star mixer and stirred at 30 r / min for 5 minutes to mix. The stirred improved silt was loaded into a mold in three layers and vibrated thoroughly to make the improved silt in the mold dense to obtain a barrier material.

[0088] Comparative Example 2

[0089] Comparative Example 2 is substantially the same as Comparative Example 1, except that: in step (1), the amount of quicklime in the improver slurry is 31.20 parts; and in step (2), the amount of marine silt with a water content of 90% is 421.2 parts.

[0090] Comparative Example 3

[0091] Comparative Example 3 is substantially the same as Comparative Example 1, except that: in step (1), the amount of quicklime in the improver slurry is 39.00 parts; and in step (2), the amount of marine silt with a water content of 90% is 429.00 parts.

[0092] Comparative Example 4

[0093] Comparative Example 4 is substantially the same as Comparative Example 1, except that: in step (1), the amount of quicklime in the improver slurry is 46.80 parts; and in step (2), the amount of marine silt with a water content of 90% is 436.80 parts.

[0094] Comparative Example 5

[0095] Comparative Example 5 is substantially the same as Comparative Example 1, except that: in step (1), the amount of quicklime in the improver slurry is 54.60 parts; and in step (2), the amount of marine silt with a moisture content of 90% is 444.60 parts.

[0096] The barrier materials in Examples 1 to 15 and Comparative Examples 1 to 5 were subjected to performance tests. The test results are shown in Table 1.

[0097] According to the existing specification "Standard for Geotechnical Test Methods" (GB / T50123-2019), the above-mentioned barrier materials are formed and cured, and then subjected to unconfined compressive strength test and flexible wall permeability test.

[0098] Table 1

[0099]

[0100]

[0101] Among them, “-” means that the test cannot be performed

[0102] As can be seen from Table 1, in the embodiments of the present invention, under the same proportions of fly ash, lithium slag powder and activated magnesium oxide, the strength of the prepared silt barrier material gradually decreases with the increase of the marine silt content. Only in Example 3, at the curing age of 28 days, the unconfined compressive strength does not meet the requirements of the vertical anti-fouling barrier (>0.1 MPa). The strength of the silt barrier material increases with the increase of the amount of lithium slag powder. In addition, the permeability coefficients of Examples 4, 7, 10, 13 and 14 meet the requirements of the anti-fouling barrier (≤1.0×10 -7 cm / s); when the modifier incorporation ratio is too low or the lithium slag powder content is insufficient, the gel formed is insufficient to modify the marine sludge to meet the requirements. Therefore, the present invention utilizes solid wastes such as fly ash and lithium slag powder to produce a sludge modifier, which is modified according to the characteristics of marine sludge and is used in vertical anti-fouling barriers. The sludge modifier of the present invention not only effectively solves the problem of solid waste material stacking and reduces the environmental burden, but also provides a feasible solution to the high moisture content and low utilization rate of marine sludge.

[0103] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A marine sludge modifier, characterized in that: The marine sludge improver consists of industrial solid waste and active magnesium oxide; wherein the industrial solid waste includes fly ash and lithium slag powder, and the mass of the industrial solid waste is not less than 85% of the total mass of the marine sludge.

2. The marine sludge modifier according to claim 1, characterized in that Calculated by mass percentage, the fly ash includes the following components: SiO2 is 45% to 55%, Al2O3 is 35% to 45%, and the content of free CaO is not more than 5%.

3. The marine sludge modifier according to claim 1, characterized in that Calculated by mass percentage, the lithium slag powder includes the following components: CaO is 40% to 50%, SiO2 is 20% to 30%, and Al2O3 is 10% to 20%.

4. The marine sludge modifier according to claim 1, characterized in that The particle sizes of the fly ash and the lithium slag powder are both 0.1-100 μm.

5. The marine sludge modifier according to claim 1, characterized in that The invention comprises the following components in parts by mass: 30 to 70 parts of fly ash, 30 to 70 parts of lithium slag powder and 10 to 15 parts of active magnesium oxide.

6. The marine sludge modifier according to claim 5, characterized in that The mass ratio of the fly ash to the lithium slag powder is 7:(3-5).

7. The method for preparing a barrier material using a marine sludge modifier according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: (1) adding fly ash, lithium slag powder and activated magnesium oxide into water in proportion and mixing them to obtain a modifier slurry; (2) The improver slurry is stirred and mixed with the marine silt, and molded using a mold to obtain the barrier material.

8. The preparation method according to claim 7, characterized in that In step (1), the ratio of the total mass of fly ash, lithium slag powder and activated magnesium oxide to the mass of water is (0.4-0.5):

1.

9. The preparation method according to claim 7, characterized in that In step (2), the water content of the marine sludge is 2 to 2.5 times its liquid limit.

10. The preparation method according to claim 7, characterized in that In step (2), the mass of the improver slurry accounts for 20 to 40% of the mass of the marine sludge.

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