A kind of vegetative concrete brick and method for greening mine slope

Abstract

The present invention provides a vegetated concrete brick and a method for regreening a mine slope. The vegetated concrete brick includes a water storage layer and a greening layer stacked in the thickness direction; the water storage layer includes, by mass ratio: 40-50 parts of modified phosphogypsum-tailing sand aggregate, 5-10 parts of tailing sand, 10-20 parts of anaerobic digestion sludge, and 10-15 parts of modified phosphogypsum; the greening layer includes, by mass ratio: 50-70 parts of modified phosphogypsum-tailing sand aggregate, 5-10 parts of tailing sand, 10-20 parts of aerobic fermentation sludge, 10-15 parts of modified phosphogypsum, 3-5 parts of seeds, and 1-2 parts of pore-forming agent; wherein the pH value of the modified phosphogypsum is 6-8; and the pH value of the tailing sand is 6-8. The vegetated concrete brick provided by the present invention limits the components and their contents in the water storage layer and the greening layer as well as the pH value, so that the pH value is moderate and suitable for plant growth, and the regreening of the mine slope can be achieved at a low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of concrete, and in particular relates to a vegetative concrete brick and a method for regreening a mine slope. Background Art

[0002] For mine slopes, there is often a lack of native soil and most of them are exposed bedrock. Currently, direct spraying and greening methods are mostly used to green mine slopes. However, this method has disadvantages such as small spraying thickness, lack of root soil, and easy erosion by rainwater. The long-term greening effect is not good. The use of vegetation concrete greening methods can effectively solve these problems.

[0003] In the prior art, the vegetation concrete is alkaline, and the pH of the water environment inside the pores is generally greater than 12, which does not meet the conditions for plant growth. The amount of cement used in the vegetation concrete directly affects the alkalinity inside the pores. As the amount of cement used decreases, the alkalinity of the vegetation concrete decreases, which can also reduce the price of the vegetation concrete. However, the extent of the alkalinity reduction is limited and still does not meet the conditions for plant growth. Therefore, achieving the greening of mine slopes at a low cost is a technical problem that needs to be solved urgently at this stage. Summary of the invention

[0004] The main purpose of the present invention is to provide a vegetation concrete brick, which can realize the greening of mine slopes at low cost.

[0005] The present invention also provides a method for regreening a mine slope. By using the above-mentioned vegetation concrete bricks, the regreening of the mine slope can be achieved at a low cost.

[0006] In a first aspect, the present invention provides a vegetated concrete brick, comprising a water storage layer and a greening layer stacked in a thickness direction;

[0007] The water storage layer comprises, by mass ratio, 40-50 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of anaerobic digestion residue, and 10-15 parts of modified phosphogypsum;

[0008] The greening layer comprises, by mass ratio, 50-70 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of aerobic fermentation sludge, 10-15 parts of modified phosphogypsum, 3-5 parts of seeds, and 1-2 parts of pore-forming agent;

[0009] Wherein, the pH value of the modified phosphogypsum is 6-8; the pH value of the tailings sand is 6-8;

[0010] The modified phosphogypsum-tailings sand aggregate is formed by fully mixing 30-50 parts by mass of modified phosphogypsum and 5-10 parts by mass of tailings sand, and then granulating.

[0011] The above-mentioned bioremediation concrete brick, wherein the average particle size D1 of the modified phosphogypsum-tailings sand aggregate in the aquifer is 2 mm < D1 < 5 mm, and the median particle size is < 4 mm;

[0012] The average particle size D2 of the modified phosphogypsum-tailings sand aggregate in the greening layer is 1.5 cm < D2 < 4 cm, and the median particle size is > 2 cm.

[0013] In the above-mentioned vegetated concrete bricks, the cylinder compressive strength of the modified phosphogypsum-tailings sand aggregate in the water storage layer and / or the greening layer is greater than 2MPa.

[0014] The above-mentioned bioremediation concrete brick, wherein the average particle size of the modified phosphogypsum is less than 0.1 mm;

[0015] The average particle size of the tailings sand is less than 0.05 mm.

[0016] In the above-mentioned phytoremediation concrete bricks, the moisture content of the anaerobic digestion residue is 30-60%, and the saturated moisture content is greater than 90%.

[0017] The phyto-concrete brick as described above, wherein the organic matter content of the anaerobic digestion residue is greater than 25%;

[0018] The organic matter content of the aerobic fermentation sludge is greater than 25%.

[0019] The above-mentioned vegetation concrete brick, wherein the porosity of the water storage layer is 10-30%;

[0020] The porosity of the greening layer is 20-50%.

[0021] The above-mentioned vegetation concrete brick is prepared by a method including the following process:

[0022] 1) performing a first pressing treatment on a first mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, anaerobic digestion sludge, and modified phosphogypsum to obtain the water storage layer;

[0023] 2) placing a second mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, aerobic fermentation sludge, modified phosphogypsum, seeds, and pore-forming agent on any surface of the water storage layer in the thickness direction, and performing a second pressing treatment to obtain a vegetated concrete brick including a water storage layer and a greening layer stacked in the thickness direction.

[0024] The bioremediation concrete brick as described above, wherein the thickness of the first mixed system is 20-30 cm, the pressure of the first pressing treatment is 200-500 tons, and the thickness of the water storage layer is 15-25 cm;

[0025] The thickness of the second mixed system is 20-30 cm, the pressure of the second pressing treatment is 100-300 tons, and the thickness of the greening layer is 17-27 cm;

[0026] The thickness of the vegetation concrete brick is 35-50cm.

[0027] In a second aspect, the present invention provides a method for regreening a mine slope, wherein the above-mentioned vegetation concrete bricks are laid on the surface of the mine slope, with the greening layer on the upper layer and the water storage layer on the lower layer.

[0028] The vegetation concrete brick provided by the present invention has a specific material composition and suitable pH, which can improve the survival rate of plants, thereby solving the problem of lack of soil and difficulty in greening the mine slope at a low cost. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. 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.

[0030] In a first aspect, the present invention provides a vegetated concrete brick, comprising a water storage layer and a greening layer stacked in a thickness direction;

[0031] The water storage layer comprises, by mass ratio, 40-50 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of anaerobic digestion residue, and 10-15 parts of modified phosphogypsum;

[0032] The greening layer comprises, by mass ratio, 50-70 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of aerobic fermentation sludge, 10-15 parts of modified phosphogypsum, 3-5 parts of seeds, and 1-2 parts of pore-forming agent;

[0033] Wherein, the pH value of the modified phosphogypsum is 6-8; the pH value of the tailings sand is 6-8;

[0034] The modified phosphogypsum-tailings sand aggregate is formed by fully mixing 30-50 parts by mass of modified phosphogypsum and 5-10 parts by mass of tailings sand, and then granulating.

[0035] It can be understood that the vegetated concrete bricks in the present invention include a water storage layer and a greening layer stacked in the thickness direction. The water storage layer is used to store water and provide water for plant growth in the greening layer, and the greening layer is used to provide an environment required for plant growth.

[0036] The modified phosphogypsum-tailings sand aggregate in the present invention is spherical or ellipsoidal, and is an aggregate formed by fully mixing 30-50 parts by mass of modified phosphogypsum and 5-10 parts by mass of tailings sand, and then granulating. It has a stable structure, strong compressive resistance, and strong adhesion after high-pressure pressing, and a stable brick structure can be achieved without adding concrete. Anaerobic digestion sludge is a product formed after anaerobic digestion and dehydration of municipal sludge or kitchen waste. Aerobic fermentation sludge is a product formed after sufficient aerobic fermentation of municipal sludge and auxiliary materials, and the auxiliary materials are rice husks or straw. The seed germination index is greater than 85%, and it can be the seeds of herbaceous plants, for example, fast-growing plants such as ryegrass, Cynodon dactylon, Cosmos, and Dwarf Sulfur Flower. Before being placed in the greening layer to prepare vegetation concrete bricks, they can be soaked in water at 30-40°C for 1-3 days. The pore-forming agent is ammonium bicarbonate or calcite, preferably ammonium bicarbonate, with an average particle size of 0.1-0.5 cm, which can provide certain pores for plant growth. In the present invention, the modified phosphogypsum, tailings sand, anaerobic digestion residue, and aerobic fermentation sludge in the water storage layer and the greening layer are all solid wastes, which not only realizes the resource utilization of solid wastes, but also greatly reduces costs.

[0037] The pH value of the modified phosphogypsum and tailings sand is limited to 6-8 in the present invention, so that the pH value of the water environment in the pores of the concrete brick can be maintained at 6.5-8, with appropriate pH value, which effectively solves the disadvantage of high alkalinity of conventional vegetation concrete materials, improves the survival rate of plants, and further solves the problem of lack of soil and difficulty in greening the mine slopes.

[0038] The present invention does not limit the modification method of the modified phosphogypsum, as long as the modified phosphogypsum with a pH value of 6-8 is obtained by modification. For example, it can be obtained by alkalizing and grinding and screening ordinary phosphogypsum with limestone powder with a particle size of less than 0.2 mm, and the obtained modified phosphogypsum is powdery and has no agglomeration phenomenon. Its organic matter content is less than 0.5%, which can avoid the decomposition of a large amount of organic matter to produce gas affecting the strength of concrete bricks.

[0039] The vegetation concrete bricks of the present invention have a specific material composition and suitable pH, which can improve the survival rate of plants, thereby solving the problem of lack of soil and difficulty in greening the mine slopes at a low cost.

[0040] In some embodiments of the present invention, the average particle size D1 of the modified phosphogypsum-tailings sand aggregate in the water reservoir is 2 mm < D1 < 5 mm, and the median particle size is < 4 mm;

[0041] The average particle size D2 of the modified phosphogypsum-tailings sand aggregate in the greening layer is 1.5 cm < D2 < 4 cm, and the median particle size is > 2 cm.

[0042] The modified phosphogypsum-tailings sand aggregate in the water reservoir of the present invention can be prepared by fully mixing 30-50 parts by mass of modified phosphogypsum and 5-10 parts by mass of tailings sand, and then putting them into a disc granulator for granulation, and controlling the aperture of the screen to control the particle size of the modified phosphogypsum-tailings sand aggregate. For example, the granulated aggregate is sieved through a double-layer screen with an aperture between 2mm and 5mm to obtain the modified phosphogypsum-tailings sand aggregate in the water reservoir, and the difference in the aperture of the two layers of screen is between 0.5mm and 2mm. The granulated aggregate is sieved through a double-layer screen with an aperture between 1.5cm and 4cm to obtain the modified phosphogypsum-tailings sand aggregate in the greening layer, and the difference in the aperture of the two layers of screen is between 0.5cm and 2cm. Among them, double-layer screen screening means that if you want to obtain particles within a specific particle size range, you need two layers of screen screening. The upper large-aperture screen blocks oversized particles, and the lower small-aperture screen removes undersized particles. The particles remaining on the lower screen are within the required particle size range.

[0043] The present invention does not limit the specific mixing process, for example, the mixing can be carried out by a horizontal drum or a vertical mixer, as long as the modified phosphogypsum and the tailings sand are mixed evenly.

[0044] It can be understood that the water storage layer in the present invention uses modified phosphogypsum-tailings sand aggregate with a smaller particle size, which can reduce the pore radius and avoid water loss on the one hand, and prevent the plant roots from growing downward too quickly and destroying the structure of the vegetation concrete bricks on the other hand; the greening layer uses modified phosphogypsum-tailings sand aggregate with a larger particle size, which can fill more nutrient matrix in the gaps between the particles on the one hand, and provide sufficient space for plant growth on the other hand.

[0045] In some embodiments of the present invention, the cylinder compressive strength of the modified phosphogypsum-tailings sand aggregate in the water storage layer and / or the greening layer is greater than 2 MPa.

[0046] The cylinder compressive strength of the modified phosphogypsum-tailings sand aggregate in the water storage layer and / or greening layer in the present invention is greater than 2MPa, and it can maintain good stability when subjected to pressure, and can maintain its structural performance during long-term use, and is not prone to problems such as cracking and breaking, thereby helping to improve the stability of the vegetation concrete bricks, avoid damage to the vegetation concrete bricks during use or transportation, and extend their service life.

[0047] In some embodiments of the present invention, the average particle size of the modified phosphogypsum is less than 0.1 mm;

[0048] The average particle size of the tailings sand is less than 0.05 mm.

[0049] The average particle size of the modified phosphogypsum described in the present invention is less than 0.1 mm, and the average particle size of the tailings sand is less than 0.05 mm, both of which are within a relatively small range. After being pressed, a water storage layer or a greening layer with a high degree of adhesion can be formed, which can improve the strength and stability of the water storage layer or the greening layer, and is conducive to further improving the stability of the vegetation concrete brick.

[0050] In addition, the SiO2 content of tailings sand is >50%, which can further improve the strength and stability of the vegetation concrete bricks.

[0051] In some embodiments of the present invention, the moisture content of the anaerobic digestion residue is 30-60%, and the saturated moisture content is greater than 90%.

[0052] The water storage layer of the present invention includes an appropriate amount of anaerobic digestion residue, and the water content of the anaerobic digestion residue is 30-60%, and the saturated water content is greater than 90%. The water content is relatively low, and the saturated water content is relatively high, which can store water to the maximum extent and provide the required water for the roots of plants, promote plant growth, and improve plant survival rate. The particle size of the anaerobic digestion residue is less than 1 mm, which is relatively small, and can further improve the water storage capacity of the water storage layer.

[0053] In some embodiments of the present invention, the organic matter content of the anaerobic digestion residue is >25%;

[0054] The organic matter content of the aerobic fermentation sludge is greater than 25%.

[0055] The water storage layer of the present invention includes an appropriate amount of anaerobic digestion residue, and the greening layer includes an appropriate amount of aerobic fermentation sludge. The organic matter content of the anaerobic digestion residue and the aerobic fermentation sludge is greater than 25%. The high organic matter content can provide a nutrient matrix for plant growth, allowing the plants to quickly germinate and regreen.

[0056] Aerobic fermentation sludge is relatively soft, which can protect the seeds from being damaged during the pressing process to form plant concrete bricks. In addition, aerobic fermentation sludge is sieved before use to obtain aerobic fermentation sludge with a particle size of 0.2-1cm, which can provide sufficient space for plant growth.

[0057] In some embodiments of the present invention, the porosity of the water storage layer is 10-30%;

[0058] The porosity of the greening layer is 20-50%.

[0059] The porosity of the water storage layer of the present invention is 10-30%, which is conducive to improving the water storage capacity of the water storage layer and can make the maximum water storage capacity of the water storage layer reach 5-10kg / m 3 .

[0060] The porosity of the greening layer of the present invention is 20-50%. On the one hand, it can accommodate more nutrients, which is beneficial to plant growth; on the other hand, it can maintain good air permeability, which is beneficial to the breathing and growth of plant roots and can also provide a certain space for plant growth.

[0061] In some embodiments of the present invention, the vegetation concrete brick is prepared by a method comprising the following process:

[0062] 1) performing a first pressing treatment on a first mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, anaerobic digestion sludge, and modified phosphogypsum to obtain the water storage layer;

[0063] 2) placing a second mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, aerobic fermentation sludge, modified phosphogypsum, seeds, and pore-forming agent on any surface of the water storage layer in the thickness direction, and performing a second pressing treatment to obtain a vegetated concrete brick including a water storage layer and a greening layer stacked in the thickness direction.

[0064] The vegetation concrete bricks of the present invention are obtained by two pressing processes.

[0065] Specifically, in step 1), a first mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, anaerobic digestion sludge, and modified phosphogypsum is placed in a high-pressure brick machine for a first pressing treatment to form a water storage layer.

[0066] In step 2), a second mixed system including modified phosphogypsum-tailings aggregate, tailings, aerobic fermentation sludge, modified phosphogypsum, seeds, and pore-forming agent is placed on any surface of the water storage layer in the thickness direction, and a high-pressure brick-making machine is used to perform a second pressing treatment on the second mixed system to form a greening layer. At this time, the water storage layer and the greening layer are tightly combined to form a vegetation concrete brick.

[0067] The vegetation concrete bricks prepared by the preparation method of the present invention have a specific material composition and suitable pH, which can improve the survival rate of plants, thereby solving the problem of lack of soil and difficulty in greening the mine slopes at a low cost. The method is simple and easy to implement with low cost.

[0068] In some embodiments of the present invention, the thickness of the first mixed system is 20-30 cm, the pressure of the first pressing treatment is 200-500 tons, and the thickness of the water storage layer is 15-25 cm;

[0069] The thickness of the second mixed system is 20-30 cm, the pressure of the second pressing treatment is 100-300 tons, and the thickness of the greening layer is 17-27 cm;

[0070] The thickness of the vegetation concrete brick is 35-50cm.

[0071] The thickness of the first mixed system is limited in the present invention, and the pressure of the first pressing treatment is within an appropriate range, so that the water storage layer can form a relatively compact structure, thereby improving its stability and strength. The thickness of the water storage layer can increase the water storage capacity of the water storage layer, and can provide sufficient water for plant growth.

[0072] The thickness of the second mixed system is limited in the present invention, and the pressure of the second pressing treatment is within an appropriate range, so that the greening layer can form a relatively stable structure, and the thickness of the greening layer can provide sufficient growth space for plant roots, which is conducive to the healthy growth of plants.

[0073] The thickness of the vegetation concrete brick in the present invention can make it have high strength and stability, and can withstand large pressure and impact. Its shape can be set according to needs, and the length and width are generally between 20-50cm.

[0074] In a second aspect, the present invention provides a method for regreening a mine slope, wherein the above-mentioned vegetation concrete bricks are laid on the surface of the mine slope, and the greening layer is on the upper layer and the water storage layer is on the lower layer. The method for regreening a mine slope in the present invention is achieved by laying the above-mentioned vegetation concrete bricks on the surface of the mine slope, thereby improving the survival rate of plants and solving the problem of lack of soil and difficulty in regreening the mine slope.

[0075] The present invention does not limit the laying method of the vegetation concrete bricks. For example, the surface of the mine slope can be leveled with a slope angle of <70°. After leveling, the surface undulation does not exceed 10 cm. Then, the greening layer of the vegetation concrete bricks is sprinkled with water until water flows out of the water storage layer. After standing for 3-5 days, the concrete bricks can be laid on the slope surface after the seeds germinate, with the greening layer on the upper layer and the water storage layer on the lower layer.

[0076] The technical solution of the present invention is further described below in conjunction with specific embodiments.

[0077] Example 1

[0078] The preparation method of the vegetation concrete brick of this embodiment comprises the following steps:

[0079] 1) Ordinary phosphogypsum is alkalized by limestone powder with a particle size of less than 0.2 mm, and then the modified phosphogypsum is obtained by grinding and screening. 45 parts by mass of modified phosphogypsum and 10 parts by mass of tailings sand are fully mixed and then put into a disc granulator for granulation. The granulated aggregate is sieved through a double-layer sieve with an aperture of 4 mm and 3 mm respectively to form modified phosphogypsum-tailings sand aggregate A; the granulated aggregate is sieved through a double-layer sieve with an aperture of 4 cm and 2 cm respectively to form modified phosphogypsum -tailings sand aggregate B; among them, the pH value of modified phosphogypsum is 7.6, and the average particle size is 0.062mm; the pH value of tailings sand is 7.3, and the average particle size is 0.023mm; the average particle size D1 of modified phosphogypsum-tailings sand aggregate A is 3.61mm, the median particle size d1 is 3.42mm, and the cylinder pressure strength is 5.1MPa; the average particle size D2 of modified phosphogypsum-tailings sand aggregate B is 2.98cm, the median particle size d2 is 3.27cm, and the cylinder pressure strength is 4.4MPa.

[0080] 2) Take 40 parts by mass of modified phosphogypsum-tailings sand aggregate A, 8 parts by mass of tailings sand, 15 parts by mass of anaerobic digestion sludge, and 10 parts by mass of modified phosphogypsum to form a first mixed system, wherein the moisture content of the anaerobic digestion sludge is 45.3%, the saturated moisture content is 99.8%, and the organic matter content is 39.3%; the thickness of the first mixed system is 25 cm, and it is placed in a high-pressure brick-making machine for the first pressing treatment with a pressure of 500 tons to form a 20.7 cm water storage layer; the porosity of the water storage layer is 14.6%.

[0081] 3) Take 65 parts by mass of modified phosphogypsum-tailings sand aggregate B, 10 parts by mass of tailings sand, 20 parts by mass of aerobic fermentation sludge, 10 parts by mass of modified phosphogypsum, 5 parts by mass of ryegrass seeds, and 2 parts of pore-forming agent and mix them evenly to form a second mixed system, wherein the organic matter content of the aerobic fermentation sludge is 30.2%, and the thickness of the second mixed system is 30 cm. It is placed on any surface of the water storage layer in the thickness direction, and a second pressing treatment is performed with a pressure of 300 tons to form a vegetated concrete brick including a water storage layer and a greening layer stacked in the thickness direction; wherein the thickness of the greening layer is 25.4 cm, the porosity of the greening layer is 29.8%, and the thickness of the vegetated concrete brick is 45.3 cm.

[0082] The method for regreening the mine slope of this embodiment comprises the following steps:

[0083] The surface of the mine slope is leveled with a slope angle of 56.7°. After leveling, the surface undulation does not exceed 10cm. Then, the greening layer of the vegetation concrete bricks is sprinkled with water until the water flows out of the water storage layer. After standing, the concrete bricks are laid on the slope surface with the greening layer on the upper layer and the water storage layer on the lower layer after the seeds germinate.

[0084] Example 2

[0085] The preparation method of the vegetation concrete brick and the method for regreening the mine slope of Example 2 are basically the same as those of Example 1, except that the pH value of the modified phosphogypsum is changed to 6.1.

[0086] Example 3

[0087] The preparation method of the vegetation concrete brick and the method for regreening the mine slope of Example 3 and Example 1 are basically the same, except that the pH value of the tailings sand is changed to 6.4.

[0088] Example 4

[0089] The preparation method of the vegetated concrete bricks and the method of mine slope regreening of Example 4 and Example 1 are basically the same, except that the average particle size D1 of the modified phosphogypsum-tailings sand aggregate A is changed to 4.32 mm and the median particle size d1 is changed to 3.95 mm.

[0090] Example 5

[0091] The preparation method of the vegetated concrete bricks and the method of mine slope regreening of Example 5 are basically the same as those of Example 1, except that the average particle size D2 of the modified phosphogypsum-tailings sand aggregate B is changed to 3.55 cm and the median particle size d2 is changed to 3.79 cm.

[0092] Example 6

[0093] The preparation method of the vegetated concrete bricks and the method of mine slope regreening of Example 6 and Example 1 are basically the same, except that the moisture content of the anaerobic digestion sludge is changed to 56.1%, the saturated moisture content is 97.2%, and the organic matter content is 31.5%.

[0094] Example 7

[0095] The preparation method of the vegetation concrete bricks and the method for regreening the mine slope of Example 7 are basically the same as those of Example 1, except that the mass fraction of the aerobic fermentation sludge is changed to 15 parts and the organic matter content is 28.3%.

[0096] Example 8

[0097] The preparation method of the vegetated concrete bricks and the method of mine slope regreening of Example 8 are basically the same as those of Example 1, except that the pressure of the first pressing treatment is changed to 300 tons, the thickness of the water storage layer is 23.3 cm, and the porosity is 23.3%.

[0098] Example 9

[0099] The preparation method of the vegetated concrete bricks and the method of mine slope regreening of Example 9 are basically the same as those of Example 1, except that the pressure of the second pressing treatment is changed to 150 tons, the thickness of the greening layer is 28.0 cm, and the porosity is 35.8%.

[0100] Comparative Example 1

[0101] The preparation method of the vegetated concrete bricks and the method for regreening the mine slope of this comparative example are basically the same as those of Example 1, except that the vegetated concrete bricks do not include an aquifer.

[0102] Comparative Example 2

[0103] The preparation method of the vegetation concrete brick and the method for regreening the mine slope in this comparative example are basically the same as those in Example 1, except that the pH value of the modified phosphogypsum is changed to 4.1.

[0104] Comparative Example 3

[0105] The preparation method of the vegetation concrete bricks and the method for regreening the mine slope in this comparative example are basically the same as those in Example 1, except that the pH value of the tailings sand is changed to 4.6.

[0106] Comparative Example 4

[0107] The preparation method of the vegetated concrete bricks and the method for regreening the mine slope in this comparative example are basically the same as those in Example 1, except that ordinary cement aggregate is used instead of modified phosphogypsum-tailings sand aggregate A and modified phosphogypsum-tailings sand aggregate B.

[0108] Table 1

[0109]

[0110] It can be seen from Table 1 that, compared with the comparative example, the vegetation concrete bricks provided by the present invention have a specific material composition and suitable pH, which can improve the survival rate of plants, thereby solving the problem of lack of soil and difficulty in greening the mine slopes at a low cost.

[0111] From the comparison between Example 1 and Comparative Examples 1-4, it can be seen that the vegetation concrete bricks provided by the present invention are used for the greening of mine slopes, which can improve the survival rate of plants.

[0112] 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A planted concrete brick, characterized in that: It includes a water storage layer and a greening layer stacked in the thickness direction; The water storage layer comprises, by mass ratio, 40-50 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of anaerobic digestion residue, and 10-15 parts of modified phosphogypsum; The greening layer comprises, by mass ratio, 50-70 parts of modified phosphogypsum-tailings sand aggregate, 5-10 parts of tailings sand, 10-20 parts of aerobic fermentation sludge, 10-15 parts of modified phosphogypsum, 3-5 parts of seeds, and 1-2 parts of pore-forming agent; Wherein, the pH value of the modified phosphogypsum is 6-8; the pH value of the tailings sand is 6-8; The modified phosphogypsum-tailings sand aggregate is formed by fully mixing 30-50 parts by mass of modified phosphogypsum and 5-10 parts by mass of tailings sand, and then granulating.

2. The vegetation concrete brick according to claim 1, characterized in that: The average particle size D1 of the modified phosphogypsum-tailings sand aggregate in the water reservoir is 2mm<D1<5mm, and the median particle size is<4mm; The average particle size D2 of the modified phosphogypsum-tailings sand aggregate in the greening layer is 1.5 cm < D2 < 4 cm, and the median particle size is > 2 cm.

3. The vegetation concrete brick according to claim 2, characterized in that: The cylinder compressive strength of the modified phosphogypsum-tailings sand aggregate in the water storage layer and / or greening layer is greater than 2MPa.

4. The vegetation concrete brick according to claim 3, characterized in that: The average particle size of the modified phosphogypsum is less than 0.1 mm; The average particle size of the tailings sand is less than 0.05 mm.

5. The vegetation concrete brick according to claim 4, characterized in that: The moisture content of the anaerobic digestion residue is 30-60%, and the saturated moisture content is greater than 90%.

6. The vegetation concrete brick according to claim 1, characterized in that: The organic matter content of the anaerobic digestion residue is greater than 25%; The organic matter content of the aerobic fermentation sludge is greater than 25%.

7. The vegetation concrete brick according to claim 1, characterized in that: The porosity of the water reservoir is 10-30%; The porosity of the greening layer is 20-50%.

8. The vegetation concrete brick according to any one of claims 1 to 7, characterized in that: The vegetation concrete brick is prepared by a method comprising the following steps: 1) performing a first pressing treatment on a first mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, anaerobic digestion sludge, and modified phosphogypsum to obtain the water storage layer; 2) placing a second mixed system including modified phosphogypsum-tailings sand aggregate, tailings sand, aerobic fermentation sludge, modified phosphogypsum, seeds, and pore-forming agent on any surface of the water storage layer in the thickness direction, and performing a second pressing treatment to obtain a vegetated concrete brick including a water storage layer and a greening layer stacked in the thickness direction.

9. The vegetation concrete brick according to claim 8, characterized in that: The thickness of the first mixed system is 20-30 cm, the pressure of the first pressing treatment is 200-500 tons, and the thickness of the water storage layer is 15-25 cm; The thickness of the second mixed system is 20-30 cm, the pressure of the second pressing treatment is 100-300 tons, and the thickness of the greening layer is 17-27 cm; The thickness of the vegetation concrete brick is 35-50cm.

10. A method for regreening a mine slope, characterized in that: The vegetation concrete bricks described in any one of claims 1 to 9 are laid on the surface of the mine slope, with the greening layer on the upper layer and the water storage layer on the lower layer.

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