Preparation method of ferromagnetic repair material for heavy metal contaminated soil

Abstract

The invention discloses a ferromagnetic repair material for heavy metal contaminated soil. The ferromagnetic repair material for the heavy metal contaminated soil is prepared from the following raw materials: attapulgite, absolute ethyl alcohol, 3-mercaptopropyltriethoxysilane, ferroferric oxide, sodium alginate, calcium oxide, zeolite and a calcium chloride solution. According to the ferromagnetic remediation material for the heavy metal contaminated soil, attapulgite entering the material is crushed and mixed through the crusher body, after crushing and sieving are completed, the attapulgite is conveyed into the stirrer body through the conveying auger to be stirred, and a second feeding opening in the top of the stirrer body can conduct primary mixing on mixed liquid; the preparation method comprises the following steps: mixing the attapulgite with water, stirring in a stirrer body after mixing, processing sulfydryl modified attapulgite, adding ferroferric oxide, zeolite and a cross-linking reagent into the stirrer body, and mixing to complete the preparation of the remediation agent, so that the remediation effect on the heavy metal contaminated soil can be enhanced by the completely mixed remediation agent.

Description

Technical Field

[0001] The present invention relates to the technical field of soil remediation materials, and specifically to a preparation method of a strong magnetic remediation material for heavy metal contaminated soil. Background Art

[0002] Soil pollution seriously threatens the functions of the ecosystem, food safety and human settlement safety, and soil pollution has characteristics such as concealment, hysteresis and accumulation. Therefore, compared with the pollution of other environmental media, soil pollution is more difficult to detect and treat. Heavy metals are the most prominent pollutants in the soil, and it is imperative to scientifically control the pollution of heavy metals in the soil. However, the causes of soil heavy metal pollution are complex and usually present the following characteristics: coexistence of multiple heavy metal pollutants, large-scale distribution in concentrated patches, which seriously affects the environmental quality. In response to multi-metal composite polluted soil, there is an urgent need to develop new materials that are easy to prepare, economical and green, and can play a long-term remediation role, so as to reasonably control the migration risk of soil pollutants. Soil heavy metal pollution not only causes a sharp reduction in the quality and yield of plants themselves, but also directly threatens the health of animals and humans, and even affects the safety of groundwater, threatening the sustainable development of social economy.

[0003] For example, in CN112547024A, a magnetic carbon composite material for repairing heavy metal contaminated soil and its preparation method, a divalent iron salt and a trivalent iron salt are mixed and then added to biomass charcoal and water and mixed evenly, so that the biomass charcoal adsorbs the divalent iron salt and the trivalent iron salt, and the liquid is naturally filtered to obtain biomass charcoal adsorbed with the divalent iron salt and the trivalent iron salt. After that, ammonia water is added and reacted to generate magnetite, and after washing with water, a magnetically modified biomass charcoal material is obtained; the magnetically modified biomass charcoal material and β-cyclodextrin modified starch are stirred and mixed evenly, and granulated to form a magnetic soil remediation material. The present invention solves the problems of complex preparation process and poor acid resistance existing in the application of existing magnetic materials in soil remediation. The present invention composites the magnetically modified biomass charcoal material through β-cyclodextrin modified starch, which can not only improve the adsorption capacity of heavy metal ions in the soil and improve the soil remediation efficiency, but also has good acid resistance. Therefore, the magnetic soil remediation material can be reused after the heavy metals are removed by dilute acid washing after recovery.

[0004] Before mixing the raw materials, the above patent did not crush the bulk or powdered materials, but directly put the bulk or powdered materials into a mixer and mixed them with other materials. However, the bulk materials themselves have a large volume and are inconvenient to mix. Some powdered materials will absorb the water vapor in the air after contacting the air, resulting in caking, and the mixing effect is also poor, which will affect the preparation of the strong magnetic remediation material for heavy metal contaminated soil. Summary of the Invention

[0005] The purpose of the present invention is to provide a preparation method of a strong magnetic remediation material for heavy metal contaminated soil, so as to solve the problem in the above-mentioned background technology that the existing strong magnetic remediation materials for heavy metal contaminated soil are not crushed before mixing, resulting in uneven mixing.

[0006] To achieve the above purpose, the present invention provides the following technical solution: A strong magnetic remediation material for heavy metal contaminated soil, the strong magnetic remediation material for heavy metal contaminated soil includes the following raw materials:

[0007] Attapulgite, absolute ethanol, 3-mercaptopropyltriethoxysilane, magnetite, sodium alginate, calcium oxide, zeolite, calcium chloride solution.

[0008] A preparation method of a strong magnetic remediation material for heavy metal contaminated soil, including the following steps:

[0009] S1. Divide the materials for repairing the soil into five groups and perform pretreatment on the five groups of materials;

[0010] S2. Feed the raw materials for producing mercapto-modified attapulgite into a crushing device for crushing treatment;

[0011] S3. Feed the treated raw materials into a stirring device for mixing and processing with other materials;

[0012] S4. Mix and process the cross-linking reagent with the raw materials;

[0013] S5. Mix and process the processed mercapto-modified attapulgite with the remaining materials to produce a material dispersion;

[0014] S6. Drop the dispersion into the calcium chloride solution to produce magnetic spheres;

[0015] S7. Wash and dry the processed magnetic spheres, and collect them with a magnetic rod to obtain a magnetic composite material.

[0016] Preferably, the five groups of materials in S1 are divided into: the first group of materials: attapulgite, the second group of materials: absolute ethanol and 3-mercaptopropyltriethoxysilane, the third group of materials: magnetite, the fourth group of materials: sodium alginate and calcium oxide, the fifth group of materials: zeolite, the sixth group of materials: calcium chloride solution.

[0017] Preferably, the raw materials for producing mercapto-modified attapulgite in S2 are absolute ethanol, 3-mercaptopropyltriethoxysilane and attapulgite, which is a mixture of the first group of raw materials and the second group of raw materials.

[0018] Preferably, the crushing device in S2 is specifically a crusher body. The material crushed by the crusher body is attapulgite. After the attapulgite is crushed, it needs to be screened through a filter plate. The unqualified attapulgite after screening will be sent back to the crusher body for re-crushing.

[0019] Preferably, the mixing device in S3 is a mixer body. The raw material processed in S3 is the attapulgite crushed and processed in S2. The other material in S3 is a mixed solution composed of anhydrous ethanol and 3-mercaptopropyltriethoxysilane. The mixed solution needs to be premixed through a second feed port before being fed into the mixer body. The mixing time in S3 is 2 - 4h. After mixing, through washing and drying, mercapto-modified attapulgite can be obtained. The mass ratio of attapulgite to water in S3 is between 1:10 and 1:20, the mass ratio of mercaptopropyltriethoxysilane to anhydrous ethanol is between 1:7 and 1:11, and the mass ratio of the mixed solution to attapulgite is between 1:2 and 1:2.5.

[0020] Preferably, the raw materials constituting the crosslinking reagent in S4 are sodium alginate and calcium oxide. The sodium alginate and calcium oxide need to be weighed before mixing, and their mass ratio is between 1:0.8 and 1:1.2.

[0021] Preferably, the mixing device in S5 is a mixer body. The mixing time of the mixer body is 30 - 50min. The materials added for mixing are the mercapto-modified attapulgite processed in S3, the crosslinking reagent processed in S4, iron tetroxide, and zeolite. The mixing ratio among these raw materials is 1 - 3 parts of mercapto-modified attapulgite, 1 - 3 parts of zeolite, 0.5 - 3 parts of iron tetroxide, and 2 - 4 parts of crosslinking reagent. After mixing, a homogeneous dispersion will be obtained. During the processing, the foam generated by mixing is eliminated by turning on an ultrasonic emitter.

[0022] Preferably, the mass ratio of the dispersion to the calcium chloride solution in S6 is between 1:0.5 and 1:2. The dispersion is dropped into the calcium chloride solution through a dropper.

[0023] Preferably, the dispersion dropped into the calcium chloride solution will form magnetic spheres. After the magnetic spheres are processed, they need to be subjected to solid-liquid separation from the calcium chloride solution and dried. The drying temperature is 80 - 105°C.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: Attapulgite is fed into the pulverizer body through the feeding port for pulverization. The motor drives two groups of pulverizing rollers to rotate in opposite directions. After the attapulgite contacts the two groups of relatively rotating pulverizing rollers, it will be broken into fine particles. These particles will fall onto the filter plate. The particles smaller than the aperture of the filter plate will pass through the filter plate, and the particles larger than the aperture of the filter plate will roll along the inclined filter plate and enter the receiving box through the second through groove. The attapulgite falling onto the conveying plate will flow into the first housing along the inclined conveying plate and rise through the rotating conveying auger inside the first housing. After the attapulgite contacts the conveying pipe, it will enter the first feeding port along the inclined conveying pipe. By pulverizing the attapulgite, it can be better mixed with other materials, improving the preparation effect of the strong magnetic remediation material for heavy metal contaminated soil.

[0025] 1. Soil pollution seriously threatens the functions of the ecosystem, food safety, and human settlement safety. Moreover, soil pollution has characteristics such as concealment, hysteresis, and accumulation. Heavy metals are the most prominent pollutants in the soil. In order to treat heavy metal pollutants, it is necessary to use strong magnetic remediation materials for soil to absorb the heavy metal components in the soil. When preparing the strong magnetic remediation material for soil, attapulgite is fed into the pulverizer body through the feeding port for pulverization. The motor drives two groups of pulverizing rollers to rotate in opposite directions. After the attapulgite contacts the two groups of relatively rotating pulverizing rollers, it will be broken into fine particles. These particles will fall onto the filter plate. The particles smaller than the aperture of the filter plate will pass through the filter plate, and the particles larger than the aperture of the filter plate will roll along the inclined filter plate and enter the receiving box through the second through groove. The attapulgite falling onto the conveying plate will flow into the first housing along the inclined conveying plate and rise through the rotating conveying auger inside the first housing. After the attapulgite contacts the conveying pipe, it will enter the first feeding port along the inclined conveying pipe. By pulverizing the attapulgite, it can be better mixed with other materials, improving the preparation effect of the strong magnetic remediation material for heavy metal contaminated soil.

[0026] 2. Soil pollution can seriously threaten the functions of the ecosystem, food safety, and human settlement safety. Moreover, soil pollution has characteristics such as concealment, lag, and accumulation. Heavy metals are the most prominent pollutants in the soil. In order to treat heavy metal pollutants, soil strong magnetic repair materials are needed to absorb and process the heavy metal components in the soil. The crushed attapulgite clay will enter the interior of the mixer body through the first feed inlet. At this time, a mixed solution needs to be added. The absolute ethanol and 3-mercaptopropyltriethoxysilane for preparing the mixed solution are fed into the second feed inlet. The second motor at the bottom of the mixer body will drive the first gear to rotate. The first gear will mesh with the second gear and the third gear, driving them to rotate in opposite directions. The two groups of gears will drive the first stirring rod and the second stirring rod to rotate in opposite directions to mix the attapulgite clay and water entering the interior of the mixer body. At the same time, the first stirring rod will drive the third stirring rod to rotate. The rotating third stirring rod will mix the absolute ethanol and 3-mercaptopropyltriethoxysilane in the second feed inlet once. Through valve control, the mixed solution after mixing will enter the mixer body through the feeding pipe to improve the preparation effect of mercapto-modified attapulgite clay. The prepared mixed solution will be discharged through the discharge outlet. In this way, through the above operations, it is possible to fully mix the heavy metal-polluted soil strong magnetic repair material during preparation and improve the preparation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the receiving box falling back of the present invention;

[0028] Figure 2 It is a schematic diagram of the receiving box rising of the present invention;

[0029] Figure 3 It is a schematic diagram of the return opening of the present invention;

[0030] Figure 4 It is a schematic diagram of the second through groove of the present invention;

[0031] Figure 5 It is a top view schematic diagram of the mixer body of the present invention;

[0032] Figure 6 It is a schematic diagram of the method flow of the present invention.

[0033] In the figure: 1, base; 2, mixer body; 3, grinder body; 4, feeding port; 5, grinding roller; 6, filter plate; 7, conveying plate; 8, first through groove; 9, first outer shell; 10, conveying auger; 11, conveying pipe; 12, first feed inlet; 13, second outer shell; 14, material receiving box; 15, threaded block; 16, first motor; 17, threaded rod; 18, return material port; 19, second motor; 20, first gear; 21, second gear; 22, third gear; 23, first stirring rod; 24, second stirring rod; 25, third stirring rod; 26, second feed inlet; 27, feeding pipe; 28, valve; 29, discharge port; 30, third feed inlet; 31, height detector; 32, baffle; 33, second through groove. Detailed implementation mode

[0034] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0035] Please refer to Figures 1-6 , the present invention provides a technical solution: a strongly magnetic repair material for heavy metal contaminated soil, and the strongly magnetic repair material for heavy metal contaminated soil includes the following raw materials:

[0036] Attapulgite, anhydrous ethanol, 3-mercaptopropyltriethoxysilane, magnetite, sodium alginate, calcium oxide, zeolite, calcium chloride solution.

[0037] A preparation method for a strongly magnetic repair material for heavy metal contaminated soil includes the following steps:

[0038] S1. Divide the materials for repairing the soil into five groups and perform pretreatment on the five groups of materials;

[0039] S2. Feed the raw materials for producing mercapto-modified attapulgite into a pulverizing device for pulverization treatment;

[0040] S3. Feed the processed raw materials into a stirring device for mixing and processing with other materials;

[0041] S4. Mix and process the crosslinking reagent with the raw materials;

[0042] S5. Mix and process the processed mercapto-modified attapulgite with the remaining materials to produce a material dispersion;

[0043] S6. Drop the dispersion into the calcium chloride solution to produce magnetic spheres;

[0044] S7. Clean and dry the processed magnetic spheres, and collect them with a magnetic rod to obtain the magnetic composite material.

[0045] The five groups of materials in S1 are as follows: the first group of materials: attapulgite; the second group of materials: absolute ethanol and 3-mercaptopropyltriethoxysilane; the third group of materials: ferroferric oxide; the fourth group of materials: sodium alginate and calcium oxide; the fifth group of materials: zeolite; the sixth group of materials: calcium chloride solution. The raw materials for producing mercapto-modified attapulgite in S2 are absolute ethanol, 3-mercaptopropyltriethoxysilane and attapulgite, which are a mixture of the first group of raw materials and the second group of raw materials. The crushing equipment in S2 is specifically the crusher body 3. The material crushed by the crusher body 3 is attapulgite. After being crushed, the attapulgite needs to be sieved through the filter plate 6. The unqualified attapulgite after sieving will be sent back to the crusher body 3 for re-crushing. The stirring equipment in S3 is the stirrer body 2. The processed raw materials in S3 are the attapulgite crushed and processed in S2. The remaining materials in S3 are a mixed solution composed of absolute ethanol and 3-mercaptopropyltriethoxysilane. The mixed solution needs to be premixed once through the second feed port 26 before being fed into the stirrer body 2. The stirring time in S3 is 2 - 4 h. After stirring and through washing and drying, mercapto-modified attapulgite can be obtained. The mass ratio of attapulgite to water in S3 is between 1:10 and 1:20, the mass ratio of 3-mercaptopropyltriethoxysilane to absolute ethanol is between 1:7 and 1:11, and the mass ratio of the mixed solution to attapulgite is between 1:2 and 1:2.5. The raw materials for forming the cross-linking reagent in S4 are sodium alginate and calcium oxide. Sodium alginate and calcium oxide need to be weighed before mixing, and their mass ratio is between 1:0.8 and 1:1.2. The mixing device in S5 is the stirrer body 2. The stirring time of the stirrer body 2 is 30 - 50 min. The materials added for stirring are the mercapto-modified attapulgite processed in S3, the cross-linking reagent processed in S4, ferroferric oxide and zeolite. The mixing ratio among these raw materials is 1 - 3 parts of mercapto-modified attapulgite, 1 - 3 parts of zeolite, 0.5 - 3 parts of ferroferric oxide, and 2 - 4 parts of cross-linking reagent. After stirring, a homogeneous dispersion will be obtained. During the processing, the ultrasonic emitter is turned on to eliminate the foam generated by stirring. The mass ratio of the dispersion to the calcium chloride solution in S6 is between 1:0.5 and 1:2. The dispersion is dropped into the calcium chloride solution through a dropper. The dispersion dropped into the calcium chloride solution will form magnetic spheres. After the magnetic spheres are processed, they need to be separated from the calcium chloride solution by solid-liquid separation and dried, and the drying temperature is 80 - 105 °C.

[0046] In specific implementation, soil pollution seriously threatens the functions of the ecosystem, food safety, and human settlement safety. Moreover, soil pollution has characteristics such as concealment, hysteresis, and accumulation. Heavy metals are the most prominent pollutants in the soil. In order to treat heavy metal pollutants, it is necessary to use a strong magnetic soil remediation material to absorb the heavy metal components in the soil. When preparing the strong magnetic soil remediation material, attapulgite is fed into the crusher body 3 through the feed port 4 for crushing. The motor drives the two groups of crushing rollers 5 to rotate in opposite directions. After the attapulgite comes into contact with the two relatively rotating crushing rollers 5, it will be broken into fine particles. These particles will fall onto the filter plate 6. The particles smaller than the aperture of the filter plate 6 will pass through the filter plate 6, and the particles larger than the aperture of the filter plate 6 will roll along the inclined filter plate 6 and enter the receiving box 14 through the second through groove 33;

[0047] The attapulgite that falls into the conveying plate 7 will flow into the first housing 9 along the inclined conveying plate 7 and rise through the rotating conveying auger 10 inside the first housing 9. After the attapulgite comes into contact with the conveying pipe 11, it will enter the first feed port 12 along the inclined conveying pipe 11. After the attapulgite larger than the particle size of the filter plate 6 falls into the receiving box 14, it will accumulate in the receiving box 14. When the height of the attapulgite in the receiving box 14 is greater than the threshold set by the height detector 31, a signal will be sent to the PLC controller, causing the PLC controller to control the first motor 16 to rotate, driving the threaded rod 17 to rotate forward, engaging in a threaded drive with the threaded block 15, and causing the receiving box 14 to rise. When the baffle 32 on one side of the receiving box 14 contacts the return port 18, the material inside the receiving box 14 will impact the baffle 32, causing the baffle 32 to rotate and open. At this time, the material inside the receiving box 14 will enter the feed port 4 through the return port 18 and be crushed again by the crushing rollers 5 until the particle size meets the requirements;

[0048] The ground attapulgite clay will enter the interior of the mixer body 2 through the first feed inlet 12. At this time, a mixed solution needs to be added. The absolute ethanol and 3-mercaptopropyltriethoxysilane used to prepare the mixed solution are fed into the second feed inlet 26. The second motor 19 at the bottom of the mixer body 2 will drive the first gear 20 to rotate. The first gear 20 will mesh with the second gear 21 and the third gear 22, driving them to rotate in opposite directions. The two sets of gears will drive the first stirring rod 23 and the second stirring rod 24 to rotate in opposite directions to mix the attapulgite clay and water entering the interior of the mixer body 2. At the same time, the first stirring rod 23 will drive the third stirring rod 25 to rotate. The rotating third stirring rod 25 will mix the absolute ethanol and 3-mercaptopropyltriethoxysilane inside the second feed inlet 26 once. Controlled by the valve 28, the mixed solution after mixing will enter the mixer body 2 through the feed pipe 27 to improve the preparation effect of the mercapto-modified attapulgite clay. The prepared mixed solution will be discharged through the discharge port 29;

[0049] The discharged mixed solution is washed and dried to obtain the mercapto-modified attapulgite clay. After mixing the constituent raw materials of the cross-linking reagent and storing them after mixing, when the mercapto-modified attapulgite clay is produced, the mercapto-modified attapulgite clay, ferric oxide, zeolite, and cross-linking reagent are mixed. After mixing, a homogeneous dispersion will be obtained. The homogeneous dispersion is collected by a container. After collection, the homogeneous dispersion is dropped into a calcium chloride solution. After the homogeneous dispersion is dropped into the calcium chloride solution, magnetic spheres will be formed. These magnetic spheres are fished out of the calcium chloride solution for cleaning and dried, and then collected using a magnetic rod to complete the preparation of the strong magnetic repair material for heavy metal-polluted soil. After the strong magnetic repair material for heavy metal-polluted soil is put into the land, it will absorb the heavy metal components in the land. Thus, through the above operations, it is possible to fully mix the strong magnetic repair material for heavy metal-polluted soil during its preparation and improve the preparation effect.

[0050] In summary, the attapulgite clay entering is crushed and mixed by the crusher body 3. After crushing and sieving, it is transported to the mixer body 2 by the conveying auger 10 for stirring. The second feed inlet 26 at the top of the mixer body 2 will mix the mixed solution once. After mixing, it is sent into the mixer body 2 for stirring to improve the processing effect of the mercapto-modified attapulgite clay and enhance the preparation effect of the strong magnetic repair material for heavy metal-polluted soil. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0051] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A strongly magnetic remediation material for heavy metal contaminated soil, characterized in that, The heavy metal contaminated soil strong magnetic remediation material comprises the following raw materials: Attapulgite, absolute ethanol, 3-mercaptopropyltriethoxysilane, ferroferric oxide, sodium alginate, calcium oxide, zeolite, calcium chloride solution.

2. A method for preparing a strongly magnetic remediation material for heavy metal contaminated soil according to claim 1, characterized in that: The preparation method comprises the following steps: S1. Divide the materials for remediating the soil into five groups, and perform pretreatment on the five groups of materials; S2. Feed the raw materials for producing mercapto-modified attapulgite into a crushing device for crushing; S3. Feed the processed raw materials into a stirring device for mixing and processing with other materials; S4. Mix and process the cross-linking reagent with the raw materials; S5. Mix and process the processed mercapto-modified attapulgite with the remaining materials to produce a material dispersion; S6. Drop the dispersion into the calcium chloride solution to produce magnetic spheres; S7. Wash and dry the processed magnetic spheres, and collect them with a magnetic bar to obtain a magnetic composite material.

3. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The five groups of materials in the S1 are divided into the first group of materials: attapulgite, the second group of materials: absolute ethanol and 3-mercaptopropyltriethoxysilane, the third group of materials: ferroferric oxide, the fourth group of materials: sodium alginate and calcium oxide, the fifth group of materials: zeolite, and the sixth group of materials: calcium chloride solution.

4. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The raw materials for producing mercapto-modified attapulgite in the S2 are absolute ethanol, 3-mercaptopropyltriethoxysilane and attapulgite, which are a mixture of the first group of raw materials and the second group of raw materials.

5. A preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The crushing device in the S2 is specifically a crusher body (3). The material crushed by the crusher body (3) is attapulgite. After the attapulgite is crushed, it needs to be screened through a filter plate (6). The unqualified attapulgite will be sent back to the crusher body (3) for re-crushing.

6. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The stirring device in the S3 is a mixer body (2). The processed raw materials in the S3 are the attapulgite crushed in the S2. The remaining materials in the S3 are a mixed solution composed of absolute ethanol and 3-mercaptopropyltriethoxysilane. The mixed solution needs to be mixed once through a second feed port (26) before being fed into the mixer body (2). The stirring time in the S3 is 2-4 h. After stirring, through washing and drying, mercapto-modified attapulgite can be obtained. The mass ratio of attapulgite to water in the S3 is between 1:10 and 1:20, the mass ratio of 3-mercaptopropyltriethoxysilane to absolute ethanol is between 1:7 and 1:11, and the mass ratio of the mixed solution to attapulgite is between 1:2 and 1:2.

5.

7. A method for preparing a strongly magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The raw materials for forming the cross-linking reagent in the S4 are sodium alginate and calcium oxide. The sodium alginate and calcium oxide need to be weighed before mixing, and the mass ratio between them is between 1:0.8 and 1:1.

2.

8. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The mixing device in S5 is a blender body (2). The mixing time of the blender body (2) is 30 - 50 minutes. The materials added for mixing are the mercapto-modified attapulgite clay processed in S3, the cross-linking reagent, iron tetroxide, and zeolite processed in S4. The mixing ratio between these raw materials is 1 - 3 parts of mercapto-modified attapulgite clay, 1 - 3 parts of zeolite, 0.5 - 3 parts of iron tetroxide, and 2 - 4 parts of cross-linking reagent. After mixing, a homogeneous dispersion will be obtained. During the processing, the ultrasonic emitter is turned on to eliminate the foam generated by stirring.

9. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: In S6, the mass ratio of the dispersion to the calcium chloride solution is between 1:0.5 and 1:

2. The dispersion is dropped into the calcium chloride solution through a dropper.

10. The preparation method of a strong magnetic remediation material for heavy metal contaminated soil according to claim 2, characterized in that: The dispersion dropped into the calcium chloride solution will form magnetic spheres. After the magnetic spheres are processed, they need to be subjected to solid-liquid separation from the calcium chloride solution and then dried. The drying temperature is 80 - 105 °C.

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