Tailings dam and tailings dam construction method

Abstract

The application discloses a tailing dam and a tailing dam construction method. The tailing dam construction method comprises the following steps: stripping a covering layer of an open-pit mine to obtain covering layer stone and covering layer fine-grained soil; forming an initial dam body by using part of the covering layer stone; spreading part of the covering layer stone on one side of the initial dam body facing a water area to form an initial anti-filtration layer; spreading the covering layer fine-grained soil on the side of the initial anti-filtration layer away from the initial dam body to form an initial impermeable layer; mining a rock layer of the open-pit mine to obtain ores and separate out coarse tailings and fine tailings; discharging the coarse tailings to the side of the initial impermeable layer away from the initial dam body to form a first transition body; discharging the fine tailings to the side of the first transition body away from the initial dam body to form a filling body; and obtaining waste stone to form a staged dam body, a second transition body and a throwing filling body. The tailing construction method of the embodiment of the application can form a tailing dam with stable structure and smooth drainage, and improves the safety of the tailing dam.

Description

Technical Field

[0001] This invention relates to the field of tailings dam technology, specifically to a tailings dam and a tailings dam construction method. Background Technology

[0002] Tailings dams are external structures of tailings ponds that impound tailings and water. Currently, most tailings dams in open-pit mines are constructed from tailings alluvial deposits, resulting in poor stability. Some are also constructed by mixing tailings with mining stripping materials. These materials are a mixture of soil and rock, with varying particle sizes and quality, making it difficult to control the dam structure. Consequently, the dam's stability is poor, leading to significant overall deformation during use and easy breakage of the anti-seepage layer. Furthermore, due to the mixed materials used in constructing tailings dams, it is impossible to establish a reliable physical model of the dam body. Seepage overflow points cannot be predicted, resulting in problems such as chaotic internal seepage flow fields and poor drainage, posing significant safety hazards. Summary of the Invention

[0003] The present invention aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of the present invention propose a tailings dam and a tailings dam construction method.

[0005] The tailings dam construction method of this invention includes the following steps:

[0006] Determine the dam construction area for the tailings dam; Construction during the infrastructure phase: Sequentially stripping the overburden and rock layers of the open-pit mine to obtain overburden stone, overburden fine-grained soil and waste rock, while simultaneously obtaining ore and separating coarse tailings and fine tailings; A portion of the overburden stone and waste rock from the infrastructure phase are spread in the dam construction area to form the initial dam body; A portion of the overburden stone material from the infrastructure phase is spread on the side of the initial dam body facing the water area to form an initial filter layer; The fine-grained soil of the overburden layer during the infrastructure construction phase is spread on the side of the initial filter layer away from the initial dam body to form the initial seepage prevention layer. The coarse tailings are discharged to the side of the initial impermeable layer away from the initial dam body to form a first transition body; The fine tailings are discharged to the side of the first transition body away from the initial dam body to form a backfill.

[0007] In some embodiments, the tailings dam construction method further includes the following steps: Production phase construction: Sequentially strip the overburden and rock layers of the open-pit mine to obtain overburden stone, overburden fine-grained soil and waste rock, while obtaining ore and separating coarse tailings and fine tailings; The waste rock material from the production period is spread on the side of the initial dam body away from the water area to form a phased dam body; A portion of the cover stone material from the production phase is spread on the side of the phased dam body facing the water area to form the phased first filter layer; A portion of the cover stone material from the production period is spread on the side of the phased first filter layer facing the water area to form the phased second filter layer; The fine-grained soil of the production period is spread on the side of the second phased filter layer facing the water area to form a phased impermeable layer.

[0008] The coarse tailings are discharged to the side of the phased seepage prevention layer away from the phased dam body to continue forming the first transition body; The fine tailings are discharged to the side of the first transition body away from the phased dam body to continue forming the filling body.

[0009] In some embodiments, there are multiple phased dam bodies, which are arranged sequentially in a direction away from the initial dam body. Two adjacent phased dam bodies are connected, the phased first filter layers corresponding to two adjacent phased dam bodies are connected, the phased second filter layers corresponding to two adjacent phased dam bodies are connected, and the phased anti-seepage layers corresponding to two adjacent phased dam bodies are connected.

[0010] In some embodiments, the initial dam body and the phased dam body constitute the dam body: A portion of the waste rock is piled on the side of the dam body away from the water area to form a second transition body; A portion of the waste rock material is dumped onto the side of the second transition body away from the dam body to form a dumping body.

[0011] In some embodiments, the horizontal cross-section of the dam body gradually increases from bottom to top.

[0012] In some embodiments, the average particle size of the phased dam body, the phased first filter layer, the phased second filter layer, and the phased seepage prevention layer decreases sequentially.

[0013] In some embodiments, the particle size of the phased dam body is 150~800mm, the particle size of the first phased filter layer is 20~200mm, the particle size of the second phased filter layer is 2~80mm, and the particle size of the phased seepage prevention layer is less than or equal to 5mm.

[0014] In some embodiments, the particle size of the initial dam body is 20-600 mm, the particle size of the initial filter layer is 2-20 mm, and the particle size of the initial anti-seepage layer is less than or equal to 5 mm; and / or, the total paving thickness of the initial filter layer and the initial anti-seepage layer is 0.2-0.3 m, the paving thickness of the phased first filter layer is 0.4-0.6 m, the paving thickness of the phased second filter layer is 0.4-0.6 m, and the paving thickness of the phased anti-seepage layer is 0.2-0.3 m.

[0015] In some embodiments, the initial dam body, the phased dam body, the initial filter layer, the initial anti-seepage layer, the phased first filter layer, the phased second filter layer, and the phased anti-seepage layer are all constructed using a layered compaction method.

[0016] Tailings dams in this embodiment of the invention include: The initial dam body is formed by spreading overburden stone and waste rock during the infrastructure construction period; An initial filter layer is located on the side of the initial dam body facing the water area, and the initial filter layer is formed by spreading the cover stone material during the construction period. An initial seepage barrier layer is provided on the side of the initial filter layer away from the initial dam body, and the initial seepage barrier layer is formed by spreading fine-grained soil from the cover layer during the construction period. The phased dam body is located on the side of the initial dam body away from the water area, and the phased dam body is formed by spreading waste rock materials from the production period. The first phased filter layer is located on the side of the phased dam body facing the water area, and the first phased filter layer is formed by spreading the cover stone waste stone during the production period. The second phased filter layer is located on the side of the first phased filter layer facing the water area, and the second phased filter layer is formed by spreading the cover stone material from the production period. The phased seepage barrier layer is located on the side of the second phased reverse filter layer facing the water area, and the phased seepage barrier layer is formed by spreading the fine-grained soil of the production phase cover layer; The first transition body is located on the side of the initial impermeable layer away from the initial dam body and the phased dam body, and the first transition body is formed by the discharge of coarse tailings. The backfill body is located on the side of the first transition body away from the initial dam body and the phased dam body, and the backfill body is formed by the discharge of fine tailings; The second transition body is located on the side of the phased dam body away from the water area, and the second transition body is constructed from waste rock. The fill material is located on the side of the second transition body away from the phased dam body, and the fill material is formed by dumping waste rock.

[0017] The tailings dam construction method of this invention allows for simultaneous open-pit mining and tailings dam construction, with the mining sequence and dam construction sequence being consistent. Materials stripped first are prioritized for stockpiling, making full use of open-pit mining waste. By employing different construction techniques for dam construction, the full and rational utilization of resources can be achieved.

[0018] Furthermore, by spreading stripping materials with different physical and mechanical properties in different dam construction areas, such as using low-permeability materials to form an anti-seepage layer and high-permeability materials to form a filter layer, and by using stripping materials with different physical and mechanical properties in different dam construction areas to form structures with different functions, the entire dam body can be rationally zoned, which can improve the overall structural strength of the tailings dam, reduce the overall deformation of the tailings dam, and improve the stability of the tailings dam body. At the same time, a reliable physical model of the dam body can be established, making the internal flow field of the tailings dam controllable and the drainage smooth. It is possible to predict the seepage overflow point and effectively control the phreatic line, thereby reducing safety hazards. Attached Figure Description

[0019] Figure 1 This is a longitudinal cross-sectional schematic diagram of an open-pit mine according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of a tailings dam according to an embodiment of the present invention.

[0021] Figure 3 yes Figure 2 Enlarged diagram of point A in the middle.

[0022] Figure label: 1. Overburden layer; 11. Gravel layer; 12. Topsoil layer; 13. Clay layer; 2. Rock layer; 21. Strongly weathered rock layer; 22. Moderately weathered rock layer; 23. Slightly weathered rock layer; 31. Initial dam body; 32. Initial filter layer; 33. Initial seepage prevention layer; 4. First transition body; 5. Filling body; 61. Phased dam body; 611. Phase 1 dam body; 612. Phase 2 dam body; 613. Phase 3 dam body; 614. Phase n dam body; 62. Phased first filter layer; 63. Phased second filter layer; 64. Phased seepage prevention layer; 7. Second transition body; 8. Concrete filling material; 91. First slope; 92. Second slope. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] like Figure 1 and Figure 2 As shown, the tailings dam construction method of this invention includes the following steps: Determine the dam construction area for the tailings dam; Construction during the infrastructure phase: Sequentially stripping the overburden layer 1 and rock layer 2 of the open-pit mine to obtain overburden stone, overburden fine-grained soil and waste rock, while obtaining ore and separating coarse tailings and fine tailings; A portion of the overburden stone and waste rock from the infrastructure construction phase will be spread in the dam construction area to form the initial dam body 31; A portion of the cover stone material during the infrastructure construction phase is laid on the side of the initial dam body 31 facing the water to form the initial filter layer 32. The fine-grained soil of the foundation period is spread on the side of the initial filter layer 32 away from the initial dam body 31 to form the initial seepage prevention layer 33. The coarse tailings are discharged to the side of the initial seepage barrier layer 33 away from the initial dam body 31 to form the first transition body 4. The fine tailings are discharged to the side of the first transition body 4 away from the initial dam body 31 to form the filling body 5.

[0025] The tailings dam construction method of this invention allows for simultaneous open-pit mining and tailings dam construction, with the mining sequence and dam construction sequence being consistent. Materials stripped first are prioritized for stockpiling, making full use of open-pit mining waste. By employing different construction techniques for dam construction, the full and rational utilization of resources can be achieved.

[0026] Furthermore, stripping materials with different physical and mechanical properties are stacked and spread separately in different dam construction areas. For example, low-permeability materials form an anti-seepage layer, and high-permeability materials form a filter layer. By using stripping materials with different physical and mechanical properties in different dam construction areas to form structures with different functions, the overall dam body is rationally zoned, which can improve the overall structural strength of the tailings dam, reduce the overall deformation of the tailings dam, and improve the stability of the tailings dam body. At the same time, a reliable physical model of the dam body can be established, making the internal flow field of the tailings dam controllable and the drainage smooth. It is possible to predict the seepage overflow point and effectively control the phreatic line, thereby reducing safety hazards.

[0027] like Figure 1As shown, the open-pit mine includes a cover layer 1 and a rock layer 2. The cover layer 1 is a Quaternary cover layer, which includes a gravel layer 11, a topsoil layer 12, and a clay layer 13. By stripping the gravel layer 11, gravel, coarse sand, and fine sand are obtained. By stripping the topsoil layer 12, topsoil (humus) is obtained. By stripping the clay layer 13, silt, clay, gravelly soil, and completely weathered material are obtained. Among them, the gravel and coarse sand obtained by stripping the gravel layer 11 and the gravelly soil obtained by stripping the clay layer 13 constitute the above-mentioned cover layer stone material. The silt, clay, and completely weathered material obtained by stripping the clay layer 13 constitute the above-mentioned cover layer fine-grained soil.

[0028] Rock layer 2 includes strongly weathered rock layer 21, moderately weathered rock layer 22, and slightly weathered rock layer 23. Mining the strongly weathered rock layer 21, moderately weathered rock layer 22, and slightly weathered rock layer 23 from top to bottom can yield ore, strongly weathered stone, moderately weathered stone, and slightly weathered stone. Among them, the tailings separated from the ore are graded (e.g., hydraulic grading or mechanical grading) to obtain coarse tailings and fine tailings. The strongly weathered stone, moderately weathered stone, and slightly weathered stone obtained from mining rock layer 2 constitute the aforementioned waste rock material.

[0029] It should be noted that the stripped topsoil cannot be used as dam construction material for tailings dams and must be stockpiled separately.

[0030] like Figure 1 As shown, open-pit mining includes infrastructure construction and production construction. Both phases involve stripping the overburden layer 1 and the rock layer 2 sequentially from top to bottom. First, the construction area is determined, and construction begins. After completion, production construction commences, expanding outwards from the infrastructure construction area. Furthermore, production construction includes the initial production phase and the production phase itself. These techniques for open-pit mining are well-known to those skilled in the art and will not be elaborated upon here.

[0031] Optionally, some of the gravel and sand from the overburden stone and some of the weathered stone from the waste rock can be spread in the dam construction area to form the initial dam body 31.

[0032] Optionally, the fine sand and some gravel of the cover stone material during the infrastructure construction period are spread on the side of the initial dam body 31 facing the water to form the initial filter layer 32.

[0033] Optionally, the fine-grained soil, silt, clay and weathered material of the foundation layer during the construction period can be spread on the outside of the initial filter layer 32 (i.e. the side away from the initial dam body 31) to form the initial seepage prevention layer 33.

[0034] In some embodiments, such as Figures 1 to 3 As shown, the tailings dam construction method also includes the following steps: Production phase construction: Sequentially stripping the overburden layer 1 and rock layer 2 of the open-pit mine to obtain overburden stone, overburden fine-grained soil and waste rock, to obtain ore and separate coarse tailings and fine tailings; Waste rock from the production period is spread on the side of the initial dam body 31 away from the water area to form the phased dam body 61. A portion of the overburden stone material from the production phase is laid on the side of the phased dam body 61 facing the water area to form the first phased filter layer 62. A portion of the cover stone material from the production period is laid on the side of the first phase filter layer 62 facing the water area to form the second phase filter layer 63. The fine-grained soil of the production period is spread on the side of the second stage filter layer 63 facing the water area to form the staged seepage prevention layer 64. The coarse tailings are discharged to the side of the phased seepage prevention layer 64 away from the phased dam body 61 to continue forming the first transition body 4; The fine tailings are discharged to the side of the first transition body 4 away from the phased dam body 61 to continue forming the filling body 5.

[0035] In some embodiments, such as Figure 1 and Figure 2 As shown, there are multiple phased dam bodies 61, which are arranged sequentially in a direction away from the initial dam body 31. Two adjacent phased dam bodies 61 are connected, the phased first filter layer 62 corresponding to two adjacent phased dam bodies 61 are connected, the phased second filter layer 63 corresponding to two adjacent phased dam bodies 61 are connected, and the phased seepage prevention layer 64 corresponding to two adjacent phased dam bodies 61 are connected.

[0036] Optionally, strongly weathered stone, moderately weathered stone, and slightly weathered stone from the waste rock are spread on the side of the initial dam body 31 away from the water area to form a phased dam body 61. Multiple phased dam bodies 61 are arranged sequentially downstream of the initial dam body 31, and the phased dam bodies 61 are connected to the initial dam body 31 and together constitute the dam body. The multiple phased dam bodies 61 are constructed in stages, and as the construction of the multiple phased dam bodies 61 continues, the total height of the dam body composed of the phased dam bodies 61 and the initial dam body 31 also increases in stages. Correspondingly, after the construction of each phased dam body 61 is completed, a first filter layer, a phased second filter layer 63, and a phased seepage prevention layer 64 need to be sequentially spread on the side of the phased dam body 61 facing the water area.

[0037] Optionally, the fine sand and gravel in the cover stone material of the production period are spread on the side of the phased dam body 61 facing the water area to form the phased first filter layer 62; the fine sand and gravel in the cover stone material of the production period are spread on the side of the phased first filter layer 62 facing the water area to form the second filter layer, wherein the average particle size of the second filter layer is smaller than the average particle size of the first filter layer.

[0038] The first stage filter layer 62 and the second stage filter layer 63 corresponding to the staged dam body 61 near the initial dam body 31 are both connected to the initial filter layer 32. The staged seepage prevention layer 64 corresponding to the staged dam body 61 near the initial dam body 31 is connected to the initial seepage prevention layer 33. The first stage filter layer 62 corresponding to two adjacent staged dam bodies 61 are connected, the second stage filter layer 63 corresponding to two adjacent staged dam bodies 61 are connected, and the staged seepage prevention layer 64 corresponding to two adjacent staged dam bodies 61 are also connected. Thus, a complete and structurally stable filter layer and seepage prevention layer can be formed on the side of the dam body facing the water.

[0039] This anti-seepage layer can lower the phreatic line, prevent water from entering the dam body, and prevent piping. This filter layer can also facilitate drainage and prevent seepage from accumulating in the dam body, thereby further lowering the phreatic line, improving the overall strength of the tailings dam, and reducing the risk of damage and deformation.

[0040] In other embodiments, the materials of the initial filter layer 32, the phased first filter layer 62, and the phased second filter layer 63 can be screened or purchased externally to meet the design requirements of the filter layers.

[0041] Optionally, the coarse tailings (unsaturated tailings) separated from the ore are discharged to the side of the initial impermeable layer 33 away from the initial dam body 31 and the phased dam body 61, that is, upstream of the initial impermeable layer 33 and the phased impermeable layer 64, to form the first transition body 4. This can create a dry beach area between the dam body and the water area, and at the same time, it can supplement the impermeable layer, isolate the water area, and extend the seepage path.

[0042] Optionally, the fine tailings (saturated tailings) separated from the ore are discharged to the side of the first transition body 4 away from the initial dam body 31 and the phased dam body 61, i.e., upstream of the first transition body 4, to form a backfill body 5. The backfill body 5 is usually below the water surface and can play a role in water retention and dust suppression.

[0043] In practical applications, a small amount of fine tailings can be mixed in the first transition body 4, and a small amount of coarse tailings can also be mixed in the filling body 5.

[0044] In other embodiments, the first transition body 4 may also be formed by a mixture of coarse tailings and fine tailings. That is, the fine tailings separated from the ore and a portion of the coarse tailings are mixed and discharged to the side of the initial anti-seepage layer 33 away from the initial dam body 31 and the phased dam body 61 to form the first transition body 4.

[0045] The first transition body 4 and the filling body 5 together form a self-healing seepage-proof structure, which can serve as a seepage-proof self-repairing layer for seepage-proof layers 33 and 64.

[0046] As an example, such as Figure 2 As shown, there are n phased dam bodies 61, meaning that the phased dam bodies 61 need to be constructed in n phases. The n phased dam bodies 61 are the first phase dam body 611, the second phase dam body 612, the third phase dam body 613, ..., the nth phase dam body 614. Correspondingly, the first phased filter layer 62, the second phased filter layer 63, the phased seepage prevention layer 64, the first transition body 4, and the filling body 5 are also constructed in n phases and match the construction steps of the phased dam bodies 61.

[0047] In some embodiments, the initial dam body 31 and the phased dam body 61 constitute the dam body: A portion of the waste rock was piled on the side of the dam away from the water area to form the second transition body 7; A portion of the waste rock material is dumped onto the side of the second transition body 7 away from the dam body to form the dumping body 8.

[0048] Optionally, the second transition body 7 is formed by piling up waste rock (mainly moderately weathered waste rock), and the fill body 8 is formed by filling waste rock (mainly moderately weathered and slightly weathered waste rock). The average particle size of the second transition body 7 is smaller than the average particle size of the fill body 8.

[0049] The second transition body 7 is located downstream of the dam body, which can effectively coordinate the deformation between the dam body and the fill body 8, while providing a good drainage channel for the entire tailings dam. The fill body 8 is located downstream of the second transition body 7, which can provide good slope protection, foundation preloading and drainage channel for the entire tailings dam. In addition, by using the fill method to fill the rockfill material obtained from the mining rock layer 2 downstream of the second transition body 7, large-scale mechanized operations can be carried out, reducing the dam construction cost.

[0050] Specifically, such as Figure 2 As shown, a first slope 91 is formed at the junction of the dam body and the second transition body 7, and a second slope 92 is formed between the second transition body 7 and the fill body 8. The slope of the first slope 91 is greater than the slope of the second slope 92. The side of the fill body 8 away from the second transition body 7 is stepped from the top to the bottom of the fill body 8. This improves the stability of the dam body, the second transition body 7, and the fill body 5.

[0051] In some embodiments, the horizontal cross-section of the dam body gradually increases from bottom to top.

[0052] The horizontal section of the dam body is parallel to the horizontal plane.

[0053] Specifically, the dam body is elongated and designed to intercept water flow. The vertical cross-section of the dam body is parallel to the vertical plane and perpendicular to the length of the dam body. Figure 2 As shown, the vertical cross-section of the dam body is conical, which can improve the overall stability of the tailings dam.

[0054] In some embodiments, the average particle size of the phased dam body 61, the phased first filter layer 62, the phased second filter layer 63, and the phased seepage prevention layer 64 decreases sequentially.

[0055] From the phased seepage prevention layer 64 to the phased dam body 61, the particle size gradually transitions from small to large, which can prevent particle loss and form a gradient of permeability coefficient from low to high. The seepage prevention layer prevents most of the water from entering the dam body, while a small amount of water passes through the seepage prevention layer and enters the filter layer. Since the filter layer has better permeability, it can quickly drain the seepage water, thereby effectively reducing the phreatic line in the dam body, improving the overall strength of the tailings dam, and reducing the risk of tailings dam damage and deformation.

[0056] In some embodiments, the particle size of the phased dam body 61 is 150~800mm, the particle size of the phased first filter layer 62 is 20~200mm, the particle size of the phased second filter layer 63 is 2~80mm, and the particle size of the phased seepage prevention layer 64 is less than or equal to 5mm.

[0057] In some embodiments, the particle size of the initial dam body 31 is 20~600mm, the particle size of the initial filter layer 32 is 2~20mm, and the particle size of the initial anti-seepage layer 33 is less than or equal to 5mm.

[0058] Optionally, the particle size of the first transition body 4 is less than or equal to 2 mm; the particle size of the filler body 5 is less than or equal to 0.1 mm.

[0059] Optionally, the particle size of the second transition body 7 is 600~1000mm; the particle size of the filler body 8 is 600~1500mm.

[0060] Therefore, the average particle size gradually increases from upstream to downstream, which can significantly reduce the seepage line inside the tailings dam and reduce the safety hazards of the tailings dam.

[0061] Furthermore, fine-grained materials (upstream) typically have higher compressibility and greater settlement, while coarse-grained materials (downstream) have lower compressibility and less settlement. By gradually varying the particle size, a gradual change in settlement can be achieved, and the various structures can form a whole. This can improve the deformation coordination of the tailings dam, avoid step-like displacement or cracks caused by excessive settlement differences at a certain interface, and improve the overall stability of the tailings dam.

[0062] In some embodiments, the initial filter layer 32 and the initial impermeable layer 33 are both paved with a thickness of 0.2~0.3m, the first phase filter layer 62 is paved with a thickness of 0.4~0.6m, the second phase filter layer 63 is paved with a thickness of 0.4~0.6m, and the impermeable layer 64 is paved with a thickness of 0.2~0.3m.

[0063] By limiting the thickness of each filter layer and seepage barrier layer as described above, a more stable filter layer and seepage barrier layer can be formed on the side of the dam facing the water, thereby reducing the risk of damage to the filter layer and seepage barrier layer and improving the overall stability of the tailings dam.

[0064] The paving thickness is the thickness of the initial filter layer 32, the initial anti-seepage layer 33, the first phase filter layer 62, the second phase filter layer 63, and the anti-seepage layer 64 before compaction.

[0065] In some embodiments, the initial dam body 31, the phased dam body 61, the initial filter layer 32, the initial anti-seepage layer 33, the phased first filter layer 62, the phased second filter layer 63, and the phased anti-seepage layer 64 are all constructed by layered compaction.

[0066] Optionally, both the initial dam body 31 and the phased dam body 61 are constructed by vibratory roller compaction in layers, and settlement is strictly controlled. After compaction, the strength index of the initial dam body 31 and the phased dam body 61 will increase significantly, thereby improving the overall strength of the tailings dam.

[0067] Optionally, the initial filter layer 32 and the initial anti-seepage layer 33 are constructed by layered compaction using one or more of the following: sheep's foot roller, bump roller, and small vibratory roller.

[0068] Optionally, both the first stage filter layer 62 and the second stage filter layer 63 are constructed by layered compaction using a small vibratory roller.

[0069] Optionally, the phased impermeable layer 64 is constructed by layered compaction using sheep's foot rollers and / or bump rollers.

[0070] Optionally, the second transition body 7 is compacted in layers using an impact roller.

[0071] Optionally, the fill material 8 may be compacted using an impact roller.

[0072] like Figure 2 As shown, the tailings dam in this embodiment of the invention includes: The initial dam body 31 is formed by the laying of overburden stone and waste rock during the infrastructure construction period; The initial filter layer 32 is located on the side of the initial dam body 31 facing the water area. The initial filter layer 32 is formed by spreading the cover stone material during the construction period. The initial seepage barrier 33 is located on the side of the initial filter layer 32 away from the initial dam body 31. The initial seepage barrier 33 is formed by spreading the fine-grained soil of the cover layer during the construction period. Phased dam body 61 is located on the side of the initial dam body 31 away from the water area. Phased dam body 61 is formed by spreading waste rock materials from the production period. The first phased filter layer 62 is located on the side of the phased dam body 61 facing the water area, and is formed by spreading the cover stone material of the production phase. The second phased filter layer 63 is located on the side of the first phased filter layer 62 facing the water area, and the second phased filter layer 63 is formed by spreading the cover stone material during the production period. The phased seepage barrier layer 64 is located on the side of the phased second filter layer 63 facing the water area. The phased seepage barrier layer 64 is formed by spreading the fine-grained soil of the production phase cover layer. The first transition body 4 is located on the side of the initial seepage barrier layer 33 and the phased dam seepage barrier layer 64 away from the initial dam body 31 and the phased dam body 61. The first transition body 4 is formed by the discharge of coarse tailings. The filling body 5 is located on the side of the first transition body 4 away from the initial dam body 31 and the phased dam body 61. The filling body 5 is formed by the discharge of fine tailings. The second transition body 7 is located on the side of the dam body away from the water area and is constructed from waste rock. The fill body 8 is located on the side of the second transition body 7 away from the dam body, and the fill body 8 is made of waste rock.

[0073] The tailings dam of this invention makes full use of open-pit mine waste and utilizes different construction techniques to achieve full and rational resource utilization. Different physical and mechanical properties of the stripping material are stacked and spread in different dam construction areas; for example, low-permeability materials form an impermeable layer, and high-permeability materials form a filter layer. The use of stripping materials with different physical and mechanical properties in different dam construction areas forms structures with different functions, ensuring reasonable zoning of the entire dam body. This improves the overall structural strength of the tailings dam, reduces overall deformation, and enhances the stability of the dam body. Simultaneously, a reliable physical model of the dam body can be established, making the internal flow field controllable and drainage smooth. It also allows for the prediction of seepage overflow points and effective control of the phreatic line, thereby reducing safety hazards.

[0074] As an example, the physical properties of the tailings dam of this embodiment of the invention, such as particle size distribution, permeability coefficient, and strength, are shown in Table 1. The quality control properties of the tailings dam, such as deformation control and dry density, are shown in Table 2. The construction control properties of the tailings dam, such as construction method and layer thickness, are shown in Table 3.

[0075] Table 1: Physical Indicators of Each Structure

[0076] Table 2: Quality Control Indicators for Each Structure

[0077] Table 3: Construction Control Indicators for Each Structure

[0078] The tailings dam structure of this invention has the following characteristics.

[0079] I. The various structural components of the tailings dam and the dam construction methods are compatible with the mining and stripping processes, development sequence, production organization plan, and physical and mechanical properties of the stripped material in the open-pit mine.

[0080] Second, the various structural components of the tailings dam make full use of the overburden from the mining area, including various types of waste soil (clay, silt, gravel, etc.), weathered stone, soft rock, hard rock, etc., to ensure that all materials are used to their fullest potential.

[0081] Third, the various structural components and construction methods of the tailings dam are designed to facilitate phased implementation, and the tailings storage in each phase is coordinated with the production of stripped material from the mining area. At the same time, the construction difficulty, cycle, and dam rising speed of the tailings dam are coordinated with the rising speed of the tailings in the reservoir.

[0082] IV. The various structural components and construction methods of the tailings dam shall be coordinated with the tailings storage and stripping material dam construction in each phase and area, and the construction in each area shall not interfere with each other, and the overall construction shall be coordinated.

[0083] V. The various structural components of the tailings dam rationally arrange the stripped materials with different physical and mechanical properties (including strength, permeability, gradation, etc.) at different times in different areas of the tailings dam. The materials stripped first are stored first, low-permeability materials are arranged in the seepage prevention zone, and high-permeability materials are arranged in the drainage zone. The dam body is rationally zoned.

[0084] VI. The structural components of the tailings dam are rationally divided, with clear physical concepts, a clear calculation model, sufficient theoretical basis, stable zonal structures (including stable seepage prevention layer structure and stable drainage layer structure), and stable overall structure.

[0085] VII. The various structural components of the tailings dam are highly adaptable, especially suitable for complex geological conditions such as soft soil areas and high seismic zones, and have good stability.

[0086] 8. The structural components and construction methods of the tailings dam meet the deformation coordination requirements of the dam construction materials during the construction and operation periods in each area, and the overall dam deformation is controllable.

[0087] 9. The various structural components and construction methods of the tailings dam facilitate mechanization and large-scale construction operations, which can reduce dam construction costs and make the project economical and reasonable while ensuring safety, stability, and deformation coordination.

[0088] 10. It can realize the integrated disposal of various solid wastes in open-pit mines, saving land and protecting the environment.

[0089] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0090] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0091] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0092] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0093] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0094] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A tailings dam construction method, characterized in that, Includes the following steps: Determine the dam construction area for the tailings dam; Construction during the infrastructure phase: Sequentially stripping the overburden (1) and rock layer (2) of the open-pit mine to obtain overburden stone, overburden fine soil and waste rock, while obtaining ore and separating coarse tailings and fine tailings; A portion of the overburden stone and the waste stone during the infrastructure construction period are spread in the dam construction area to form the initial dam body (31). A portion of the overburden stone material during the infrastructure phase is spread on the side of the initial dam body (31) facing the water area to form an initial filter layer (32). The fine-grained soil of the overburden layer during the construction period is spread on the side of the initial filter layer (32) away from the initial dam body (31) to form the initial seepage prevention layer (33). The coarse tailings are discharged to the side of the initial seepage barrier layer (33) away from the initial dam body (31) to form the first transition body (4). The fine tailings are discharged to the side of the first transition body (4) away from the initial dam body (31) to form a backfill body (5).

2. The tailings dam construction method according to claim 1, characterized in that, It also includes the following steps: Production period construction: Sequentially strip the overburden (1) and rock layer (2) of the open-pit mine to obtain overburden stone, overburden fine soil and waste rock, while obtaining ore and separating coarse tailings and fine tailings; The waste rock material from the production period is spread on the side of the initial dam body (31) away from the water area to form the phased dam body (61). A portion of the cover stone material from the production period is spread on the side of the phased dam body (61) facing the water area to form the phased first filter layer (62). A portion of the cover stone material from the production period is spread on the side of the phased first filter layer (62) facing the water area to form the phased second filter layer (63). The fine-grained soil of the production period is spread on the side of the phased second filter layer (63) facing the water area to form a phased impermeable layer (64). The coarse tailings are discharged to the side of the phased seepage prevention layer (64) away from the phased dam body (61) to continue forming the first transition body (4). The fine tailings are discharged to the side of the first transition body (4) away from the phased dam body (61) to continue forming the filling body (5).

3. The tailings dam construction method according to claim 2, characterized in that, The number of phased dam bodies (61) is multiple. The multiple phased dam bodies (61) are arranged sequentially in a direction away from the initial dam body (31). Two adjacent phased dam bodies (61) are connected. The phased first filter layer (62) corresponding to two adjacent phased dam bodies (61) is connected. The phased second filter layer (63) corresponding to two adjacent phased dam bodies (61) is connected. The phased seepage prevention layer (64) corresponding to two adjacent phased dam bodies (61) is connected.

4. The tailings dam construction method according to claim 2, characterized in that, The initial dam body (31) and the phased dam body (61) constitute the dam body: A portion of the waste rock is piled on the side of the dam away from the water area to form a second transition body (7). A portion of the waste rock material is dumped onto the side of the second transition body (7) away from the dam body to form a dumping body (8).

5. The tailings dam construction method according to claim 4, characterized in that, The horizontal cross-section of the dam body gradually increases from bottom to top.

6. The tailings dam construction method according to claim 2, characterized in that, The average particle size of the phased dam body (61), the phased first filter layer (62), the phased second filter layer (63), and the phased seepage prevention layer (64) decreases sequentially.

7. The tailings dam construction method according to claim 6, characterized in that, The particle size of the phased dam body (61) is 150~800mm, the particle size of the first phased filter layer (62) is 20~200mm, the particle size of the second phased filter layer (63) is 2~80mm, and the particle size of the phased seepage prevention layer (64) is less than or equal to 5mm.

8. The tailings dam construction method according to claim 2, characterized in that, The initial dam body (31) has a particle size of 20~600mm, the initial filter layer (32) has a particle size of 2~20mm, and the initial anti-seepage layer (33) has a particle size of less than or equal to 5mm; and / or, The initial filter layer (32) and the initial anti-seepage layer (33) are both 0.2~0.3m thick, the first phase filter layer (62) is 0.4~0.6m thick, the second phase filter layer (63) is 0.4~0.6m thick, and the anti-seepage layer (64) is 0.2~0.3m thick.

9. The tailings dam construction method according to any one of claims 2-8, characterized in that, The initial dam body (31), the phased dam body (61), the initial filter layer (32), the initial anti-seepage layer (33), the phased first filter layer (62), the phased second filter layer (63), and the phased anti-seepage layer (64) are all constructed by layered compaction.

10. A tailings dam, characterized in that, include: The initial dam body (31) is formed by spreading the overburden stone and the waste rock during the construction period; An initial filter layer (32) is provided on the side of the initial dam body (31) facing the water area. The initial filter layer (32) is formed by spreading the cover stone material during the construction period. An initial seepage barrier (33) is provided on the side of the initial filter layer (32) away from the initial dam body (31). The initial seepage barrier (33) is formed by spreading the fine-grained soil of the cover layer during the construction period. Phased dam body (61), the phased dam body (61) is located on the side of the initial dam body (31) away from the water area, the phased dam body (61) is formed by spreading waste rock materials from the production period; The first phased filter layer (62) is located on the side of the phased dam body (61) facing the water area. The first phased filter layer (62) is formed by spreading the cover stone material during the production period. The second staged filter layer (63) is located on the side of the first staged filter layer (62) facing the water area, and the second staged filter layer (63) is formed by spreading the cover stone material during the production period; Phased seepage barrier layer (64), the phased seepage barrier layer (64) is located on the side of the phased second filter layer (63) facing the water area, the phased seepage barrier layer (64) is formed by spreading fine-grained soil from the production phase cover layer; The first transition body (4) is located on the side of the initial seepage barrier layer (33) and the phased dam seepage barrier layer (64) away from the initial dam body (31) and the phased dam body (61), and the first transition body (4) is formed by the discharge of the coarse tailings. The filling body (5) is located on the side of the first transition body (4) away from the initial dam body (31) and the phased dam body (61), and the filling body (5) is formed by the discharge of the fine tailings; The second transition body (7) is located on the side of the phased dam body (61) away from the water area. The second transition body (7) is constructed from waste rock. The filler (8) is located on the side of the second transition body (7) away from the phased dam body (61), and the filler (8) is made of waste rock.

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