Method for preparing highway subgrade material based on yellow phosphorus slag and phosphogypsum

Abstract

The invention discloses a method for preparing a highway subgrade material based on yellow phosphorus slag and ardealite, which comprises the following steps: 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag; 2) screening granular yellow phosphorus slag, taking coarse grains as yellow phosphorus slag aggregate for later use, and grinding fine grains into powdery yellow phosphorus slag; 3) mixing the powdery yellow phosphorus slag with ardealite, fly ash, blast furnace slag and quick lime to obtain a cementing material; and 4) adding water into the yellow phosphorus slag aggregate and the cementing material, mixing, filling the cementing material powder into holes of the yellow phosphorus slag aggregate, and gelatinizing and curing. According to the invention, the defects of more surface edges and corners, more pores on particles, free fluorine and the like of the yellow phosphorus slag are overcome through lower processing cost, so that the yellow phosphorus slag can be applied to roadbed filler on a large scale, and the resource reutilization efficiency of the yellow phosphorus slag is improved.

Description

Technical Field

[0001] The invention relates to the technical field of phosphorus chemical solid waste treatment and highway subgrade material preparation, in particular to a method for preparing a highway subgrade material based on yellow phosphorus slag and phosphogypsum. Background Art

[0002] Phosphorus chemical industry is an important chemical industry, and its main products include yellow phosphorus, phosphoric acid, phosphate fertilizer, fine phosphate, etc. Among them, a large amount of yellow phosphorus slag solid waste residue is produced in the process of yellow phosphorus production, and a large amount of phosphogypsum by-product is produced in the process of wet phosphoric acid production. The storage of these solid wastes not only occupies a large amount of land, but also pollutes the environment. Therefore, how to effectively utilize these phosphorus chemical solid wastes and realize waste resource utilization is an urgent problem to be solved in the current phosphorus chemical industry. The existing solutions are mainly to treat phosphorus chemical solid wastes by physical or chemical methods, and then apply them to other fields. For example, phosphorus chemical solid wastes can be used to prepare building materials such as cement and concrete. In addition, there are also some studies that try to use phosphorus chemical solid wastes to prepare highway subgrade materials. Highway subgrade materials are an important part of highway construction, and their quality directly affects the performance and life of the highway. Traditional highway subgrade materials are mainly natural sand and gravel, and they are too dependent on natural resources. However, with the improvement of environmental protection requirements and the increasing shortage of resources, the research on the preparation of highway subgrade materials using industrial solid wastes has received more and more attention.

[0003] For example, in China's patent CN114751708A, phosphogypsum is used as the main raw material, and mineral admixtures and alkaline activators are used to prepare embankment fillers. In the existing technology of preparing roads with solid waste residue from phosphorus chemical industry as raw materials, phosphogypsum is mostly used as the main material, but phosphogypsum as powder is not conducive to improving the compressive strength of roadbed fillers; at the same time, excessive use of phosphogypsum will affect the pH value of groundwater, which is not conducive to the protection of surrounding groundwater resources.

[0004] At present, the amount of yellow phosphorus slag added to the existing building material formula is relatively small, which is mainly limited by the characteristics of yellow phosphorus slag, such as many edges and corners on the surface, many pores on the particles, and free fluorine. When using yellow phosphorus slag, the existing process requires that all yellow phosphorus slag be ground into fine powder, which also makes its application cost high, making it difficult to increase the application of yellow phosphorus slag solid waste. For an enterprise that wants to recycle solid waste resources, the total amount of yellow phosphorus slag produced in a production year may be far higher than the total amount of yellow phosphorus slag reused in that year, and the consumption and production cannot reach a dynamic balance. For yellow phosphorus production enterprises, it is necessary to waste land space to pile up excess yellow phosphorus slag, and it also costs money to manage the untreated yellow phosphorus slag. Long-term stacking will also affect the soil environment. Therefore, enterprises have low efficiency in recycling yellow phosphorus slag.

[0005] Therefore, a method for preparing roadbed filler with yellow phosphorus slag as the main raw material is needed, which is beneficial for yellow phosphorus production enterprises to improve the defects of yellow phosphorus slag in a low-cost manner, expand the amount of yellow phosphorus slag in roadbed filler, and improve the recycling efficiency of yellow phosphorus slag. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a highway subgrade material based on yellow phosphorus slag and phosphogypsum and a preparation method thereof.

[0007] The purpose of the present invention is achieved by the following technical solution: A method for preparing a highway subgrade material based on yellow phosphorus slag and phosphogypsum comprises the following steps:

[0008] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag; in this step, the yellow phosphorus slag is crushed and shaped to change its physical properties, reduce the surface angularity of the slag particles, make the slag particles regular in shape, smooth in surface, and evenly distributed in the subsequent mixture, so as to better fill the gaps in the mixture, increase the density and durability of the mixture, and reduce the degree of cracking of the mixture, thereby improving the strength and durability of the mixture and extending the service life of the concrete structure. This step does not require the yellow phosphorus slag to be completely ground, has low energy consumption, and is conducive to reducing processing costs;

[0009] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate, and grinding the fine particles into powdered yellow phosphorus slag; in this step, only the fine particles are ground, which has low energy consumption and is conducive to reducing processing costs, while the coarse particles of yellow phosphorus slag still have holes on their surface, and using them directly as aggregate is not conducive to increasing the structural strength of the roadbed filler, so the following steps 3) and 4) are required for further modification;

[0010] 3) Mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material; in this step, the alkaline oxides in the combination of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime can react with the fluoride in the yellow phosphorus slag after subsequent water mixing, solidifying the free fluorine to produce calcium fluoride, and combining it with the aggregate, which not only improves the structural strength, but also reduces the fluorine content of the leached product, greatly improving the application defects of the yellow phosphorus slag;

[0011] 4) Adding water to the yellow phosphorus slag aggregate and the cementitious material and mixing them, and filling the cementitious material powder into the holes of the yellow phosphorus slag aggregate and solidifying them by gelling; in this step, powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag, quicklime and other powders are filled into the holes of the yellow phosphorus slag aggregate, and solidification is stimulated during the mixing process of adding water, which has the effect of tightly filling the holes, greatly improving the structural strength, improving the application defects of the yellow phosphorus slag, and increasing the amount of the yellow phosphorus slag in the formulation of building materials such as roadbed fillers without affecting the compressive strength;

[0012] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0013] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm; the particle size of the powdered yellow phosphorus slag needs to be controlled. If the particle size of the yellow phosphorus slag powder is too large, it cannot be effectively filled into the holes of the yellow phosphorus slag aggregate, and if the particle size is too small, the grinding energy consumption is too large and the cost is too high, which is not conducive to improving the application efficiency of the yellow phosphorus slag in the roadbed filler;

[0014] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:(1-10):(0.01-0.2):(1-10):(0.01-0.05); at this ratio, it is conducive to reasonably coordinating various components to maximize their effects, so that the compressive strength of the finally prepared roadbed filler is optimal and the fluorine content in the leaching product is lowest;

[0015] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:(2-10); under this ratio, the cementitious material is evenly filled into the pores of the yellow phosphorus slag aggregate and solidified to achieve tight filling, thereby overcoming the structural defects of the yellow phosphorus slag aggregate and making the compressive strength of the finally prepared roadbed filler optimal;

[0016] In step 4), the amount of water added during mixing is 15% to 20% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0017] In the step 4), the mixing residence time is 1 to 10 minutes, and the stirring speed is 10 to 30 r / min. Only when a certain stirring time and stirring speed are reached can the cementitious material and the yellow phosphorus slag aggregate be fully mixed, and the cementitious material be fully filled and solidified in the pores of the yellow phosphorus slag aggregate.

[0018] The present invention also provides a highway subgrade material prepared based on yellow phosphorus slag and phosphogypsum, which is prepared by using the above-mentioned method for preparing a highway subgrade material based on yellow phosphorus slag and phosphogypsum.

[0019] The present invention has the following advantages:

[0020] 1. The present invention overcomes the defects of yellow phosphorus slag itself, such as many surface edges and corners, many pores on particles, and free fluorine, by means of relatively low processing cost, so that yellow phosphorus slag can be applied to roadbed fillers on a large scale, thereby improving the resource recycling efficiency of yellow phosphorus slag. For particles with porous structures such as yellow phosphorus slag, it is difficult to use them as coarse aggregates in large quantities by conventional technical means. However, by combining the yellow phosphorus slag with a special component of a cementitious material, the cementitious material can be filled into the holes, and an excitation reaction is generated in the holes after mixing with water, and the holes are filled and supported more tightly after solidification, thereby improving the compressive strength of the roadbed filler. At the same time, the special component of the cementitious material can solidify the free fluorine on the yellow phosphorus slag to generate calcium fluoride under the action of water, thereby reducing the fluorine content of the roadbed filler extract.

[0021] 2. The present invention not only increases the amount of yellow phosphorus slag used in roadbed fillers, but also helps yellow phosphorus production enterprises improve the defects of yellow phosphorus slag in a low-cost manner and improve the utilization efficiency of yellow phosphorus slag. DETAILED DESCRIPTION

[0022] 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 described clearly and completely below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. The components of the embodiments of the present invention described and shown herein can be arranged and designed in various different configurations.

[0023] Therefore, the following detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0026] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate the orientation or position relationship as shown, or the orientation or position relationship in which the product of the invention is usually placed when in use, or the orientation or position relationship commonly understood by those skilled in the art, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0027] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] Example 1: A method for preparing a highway subgrade material based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0029] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0030] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0031] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0032] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0033] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0034] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0035] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:(1-10):(0.01-0.2):(1-10):(0.01-0.05);

[0036] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:(2-10);

[0037] In step 4), the amount of water added during mixing is 15% to 20% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0038] In the step 4), the mixing residence time is 1 to 10 minutes, and the stirring speed is 10 to 30 r / min.

[0039] The method of this embodiment uses a relatively low processing cost to prepare a highway subgrade material based on yellow phosphorus slag and phosphogypsum, thereby overcoming the defects of yellow phosphorus slag itself, such as many surface edges and corners, many pores on particles, and free fluorine, so that yellow phosphorus slag can be used on a large scale as a subgrade filler, thereby improving the resource recycling efficiency of yellow phosphorus slag. For particles with porous structures such as yellow phosphorus slag, the compressive resistance is insufficient, and it is difficult to use it in large quantities as a coarse aggregate by conventional technical means. However, by combining it with a cementitious material of a special component, the cementitious material can be filled into the holes, and after mixing with water, an excitation reaction is generated in the holes, and after solidification, the holes are filled and supported more tightly, thereby improving the compressive strength of the subgrade filler. At the same time, the cementitious material of the special component can, under the action of water, solidify the free fluorine on the yellow phosphorus slag to form calcium fluoride, thereby reducing the fluorine content of the subgrade filler extract.

[0040] Embodiment 2: A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0041] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0042] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0043] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0044] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0045] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0046] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0047] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:1:0.01:1:0.01;

[0048] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:2;

[0049] In step 4), the amount of water added during mixing is 20% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0050] In the step 4), the mixing residence time is 1 min and the stirring speed is 30 r / min.

[0051] Embodiment 3: A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0052] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0053] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0054] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0055] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0056] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0057] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0058] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:10:0.2:10:0.05;

[0059] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:10;

[0060] In step 4), the amount of water added during mixing is 15% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0061] In the step 4), the mixing residence time is 10 min and the stirring speed is 10 r / min.

[0062] Embodiment 4: A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0063] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0064] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0065] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0066] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0067] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0068] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0069] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:8:0.15:4:0.04;

[0070] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:4;

[0071] In step 4), the amount of water added during mixing is 18% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0072] In the step 4), the mixing residence time is 6 minutes and the stirring speed is 20 r / min.

[0073] Example 5: A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0074] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0075] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0076] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0077] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0078] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0079] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0080] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:6:0.1:8:0.02;

[0081] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:8;

[0082] In step 4), the amount of water added during mixing is 16% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0083] In the step 4), the mixing residence time is 4 minutes and the stirring speed is 15 r / min.

[0084] Example 6: A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, comprising the following steps:

[0085] 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag;

[0086] 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag;

[0087] 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material;

[0088] 4) mixing the yellow phosphorus slag aggregate and the cementitious material with water, filling the cementitious material powder into the pores of the yellow phosphorus slag aggregate and gelling and solidifying;

[0089] In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates for later use, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag;

[0090] In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm;

[0091] In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:4:0.1:6:0.03;

[0092] In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:6;

[0093] In step 4), the amount of water added during mixing is 17% of the total mass of the cementitious material and the yellow phosphorus slag aggregate;

[0094] In the step 4), the mixing residence time is 8 minutes and the stirring speed is 24 r / min.

[0095] Example 7: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided, the difference being that the particle size of the powdered yellow phosphorus slag is greater than 0.075 mm, and the particle size of the powdered yellow phosphorus slag obtained by grinding in this example is in the range of 0.3 mm to 0.5 mm.

[0096] Example 8: On the basis of Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided, the difference being that the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:0.5:0.005:0.5:0.1.

[0097] Example 9: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided. The difference lies in that no yellow phosphorus slag is used as aggregate. Powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime are directly mixed in a mass ratio of 1:4:0.1:6:0.03, and water is added to mix to prepare the subgrade filler.

[0098] Example 10: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided, the difference being that there is no powdered yellow phosphorus slag in the cementitious material, the mass ratio of phosphogypsum, fly ash, blast furnace slag and quicklime is 4:0.1:6:0.03, the mass ratio of cementitious material and yellow phosphorus slag aggregate is 1:6, and water is added and mixed to prepare the roadbed filler.

[0099] Example 11: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided. The difference lies in that there is neither yellow phosphorus slag aggregate nor powdered yellow phosphorus slag. The cementitious material prepared from phosphogypsum, fly ash, blast furnace slag and quicklime is directly mixed in a mass ratio of 4:0.1:6:0.03, and water is added to mix to prepare the subgrade filler.

[0100] Example 12: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided. The difference lies in that the cementitious material contains only powdered yellow phosphorus slag, phosphogypsum, fly ash and blast furnace slag, and the mass ratio is 1:4:0.1:6. The cementitious material and yellow phosphorus slag aggregate are mixed with water to prepare the subgrade filler.

[0101] Example 13: Based on Example 6, a method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum is provided. The difference lies in that the cementitious material contains only powdered yellow phosphorus slag, fly ash, blast furnace slag and quicklime, and the mass ratio is 1:0.1:6:0.03. The cementitious material and yellow phosphorus slag aggregate are mixed with water to prepare the subgrade filler.

[0102] The roadbed filler prepared in the above-mentioned Example 2-13 was prepared according to the type I-1 test in the compaction test (T 0131-2019) of the "Highway Geotechnical Test Code" (JTG3430-2020), and then placed in a standard concrete curing box for curing to obtain a sample to be tested. The unconfined compressive strength of the sample to be tested at different ages was tested according to the "Highway Geotechnical Test Code" (JTG 3430-2020), and the leaching solution was prepared by the "Solid Waste Leaching Toxicity Leaching Method Horizontal Oscillation Method" (HJ 557-2010) method, and the pH value of the leaching solution was determined by the "Water Quality pH Value Determination Electrode Method" (HJ 1147-2020) method, and the fluoride content of the leaching solution was determined by the "Water Quality Fluoride Determination Ion Selective Electrode Method" (GB 7484-1987) method. The measurement results are shown in Table 1.

[0103] Table 1 Test results of roadbed filler performance prepared in Examples 2-13

[0104]

[0105] From the results of Example 6 in Table 1, it can be seen that the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:4:0.1:6:0.03, the mass ratio of cementitious material to yellow phosphorus slag aggregate is 1:6, and when the particle size of the powdered yellow phosphorus slag is less than 0.075 mm, the compressive strength performance of the roadbed filler at 180 d is the best, the content of fluoride in the leachate is the smallest, and its pH value is closest to neutral, indicating that the impact on the groundwater environment is minimal; from the results of Example 7, it can be seen that when the particle size of the powdered yellow phosphorus slag is greater than 0.075 mm, the compressive strength is significantly reduced. This may be because the powdered yellow phosphorus slag cannot be evenly dispersed with other materials and filled into the holes of the aggregate, resulting in the effect of adding water to stimulate the reaction being affected, making it impossible for the holes of the aggregate to be tightly filled, while reducing the solidified free fluorine, resulting in an increase in the fluoride content of the leachate. It can be seen from the results of Example 9 and Example 10 in Table 1 that the aggregate and powdered yellow phosphorus slag play a synergistic role in the compressive strength of the roadbed filler, and both are indispensable.

[0106] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum, characterized in that: The steps include: 1) crushing yellow phosphorus slag to obtain granular yellow phosphorus slag; 2) screening the granular yellow phosphorus slag, using the coarse particles as yellow phosphorus slag aggregate for later use, and grinding the fine particles into powdered yellow phosphorus slag; 3) mixing powdered yellow phosphorus slag with phosphogypsum, fly ash, blast furnace slag and quicklime to obtain a cementitious material; 4) Mix the yellow phosphorus slag aggregate and the cementitious material with water, and fill the cementitious material powder into the pores of the yellow phosphorus slag aggregate and solidify it by gelling.

2. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In step 2), the granular yellow phosphorus slag is sieved with a mesh size of 30 meshes, the coarse particles are used as yellow phosphorus slag aggregates, and the fine particles are ground and passed through a 200-mesh sieve to obtain powdered yellow phosphorus slag.

3. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In step 2), the particle size of the powdered yellow phosphorus slag is less than 0.075 mm.

4. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In step 3), the mass ratio of powdered yellow phosphorus slag, phosphogypsum, fly ash, blast furnace slag and quicklime is 1:(1-10):(0.01-0.2):(1-10):(0.01-0.05).

5. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In step 4), the mass ratio of the cementitious material to the yellow phosphorus slag aggregate is 1:(2-10).

6. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In step 4), the amount of water added during mixing is 15% to 20% of the total mass of the cementitious material and the yellow phosphorus slag aggregate.

7. The method for preparing highway subgrade materials based on yellow phosphorus slag and phosphogypsum according to claim 1, characterized in that: In the step 4), the mixing residence time is 1 to 10 minutes, and the stirring speed is 10 to 30 r / min.

8. A method for preparing a highway subgrade material based on yellow phosphorus slag and phosphogypsum, characterized in that: The roadbed material is prepared by the method for preparing roadbed material based on yellow phosphorus slag and phosphogypsum as described in any one of claims 1 to 7.

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