A tailings damming process to address insufficient clarification distance

Abstract

This invention relates to a tailings dam construction process to address insufficient clarification distance, comprising the following steps: Step 1, material extraction; Step 2, transportation and road preparation; Step 3, piling and compaction; Step 4, shaping and protection: the preliminary dam body is sloped and shaped to form a wide-topped dam with specified outer and inner slope ratios; the dam height and dry beach length are determined according to the tailings dam grade; Step 5, post-treatment. This invention, by constructing an "artificial dry beach," i.e., a wide-topped dam, can effectively extend the water flow path, ensuring sufficient settling of suspended solids, thereby guaranteeing the quality of the backwater and the safety of the dam for flood control.

Description

Technical Field

[0001] This invention relates to the field of mine dam construction technology, and in particular to a tailings dam construction process that solves the problem of insufficient clarification distance. Background Technology

[0002] Tailings damming is an engineering project that uses tailings or earthwork to construct retaining walls to enclose storage space for mineral processing waste. Since mineral processing tailings are mostly fine sand, open and scattered dumping of tailings easily leads to dust storms and rainwater runoff, polluting the soil and water. Furthermore, mineral processing generates large amounts of wastewater, and indiscriminate discharge of this wastewater negatively impacts the surrounding environment. Therefore, tailings damming not only centrally collects tailings waste, enabling wastewater storage and reuse and preventing direct discharge into surrounding waterways, but also prevents tailings from forming mudslides during flash floods and heavy rains, constrains storage boundaries, prevents waste from encroaching on farmland and waterways, and reduces the risk of geological disasters. Simultaneously, the dam body can be sustainably expanded in stages, facilitating the comprehensive resource utilization of tailings in the long term, such as dry disposal, reprocessing, and the production of building materials.

[0003] In the later stages of service of upstream wet tailings dams, the dam axis continuously advances upstream, significantly shortening the effective clarification distance between the tailings discharge point and the fixed flood discharge outlet and return water intake point. Insufficient clarification distance prevents suspended solids in the tailings slurry from settling sufficiently, resulting in turbid return water, severely impacting the water safety of the concentrator and exacerbating pipeline wear and blockage. Traditional methods such as decentralized discharge, centralized discharge, or pond filling are ineffective in solving this technical challenge at this stage. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a tailings dam construction technology that solves the problem of insufficient clarification distance. By constructing an "artificial dry beach," namely a wide-topped dam, the water flow path can be effectively extended, ensuring sufficient settling of suspended solids, thereby guaranteeing the quality of the backwater and the safety of the dam for flood control.

[0005] The technical solution adopted in this invention is as follows: The tailings damming technology proposed in this invention to solve the problem of insufficient clarification distance includes the following steps: Step 1, Material Extraction: In the dry beach area of ​​the tailings dam, away from the water and close to the mountain, excavate the consolidated dry tailings sand as dam construction material; Step 2, Transportation and Road Preparation: Transport the dry tailings sand to the designated area in front of the dam; before operation, the road surface must be laid and compacted to form a stable equipment operation and transportation channel; Step 3, Piling and Compaction: The unloaded dry tailings sand is gradually pushed towards the water area of ​​the reservoir, spread out, and compacted in layers to form the initial shape of the dam; Step 4, Shaping and Protection: The initially formed dam body is shaped by slope trimming to form a wide-top dam with specified outer and inner slope ratios; the dam height and dry beach length are determined according to the tailings dam grade. Step 5: Post-processing.

[0006] Furthermore, in step 4, the outer slope ratio of the wide-topped dam is 1:3, and the inner slope ratio is 1:2.

[0007] Furthermore, in step 4, the dam height must ensure that the difference between the top of the beach and the water level is >2m, and the dry beach length is ≥100m.

[0008] Furthermore, the inner slope of the wide-top dam is the water-facing side, and its surface is covered with geotextile to prevent water seepage from causing piping.

[0009] Furthermore, step 5 includes: covering the surface of the constructed wide-topped dam with topsoil and compacting it to prevent dust, while setting up water level gauges and safety warning signs on the water-facing side.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention constructs a "wide-top dam" to actively extend the clarification distance, thereby fundamentally ensuring that the water quality of backwater and flood discharge meets the standards.

[0011] 2. This invention ensures key flood control parameters such as the safe superelevation of the dam body and the minimum dry beach length, which can significantly improve the safety level of the tailings dam at the end of its operation.

[0012] 3. This invention utilizes readily available dry tailings sand in the reservoir as material, resulting in low cost; the process route is clear, highly operable, and has high construction efficiency, saving manpower and material resources.

[0013] 4. This invention enables the recycling of tailings resources within the dam and effectively suppresses dust pollution through soil covering measures.

[0014] 5. Feedback results after the practical application of this invention show that the process is safe and reliable, the effect is significant, and it has extremely high industry promotion value. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the construction process of the wide-top dam in this invention; Figure 2 This is a schematic diagram of the structure of the wide-topped dam in this invention.

[0016] The attached diagram is labeled as follows: 1-Wide-top dam; 2-Soil; 3-Geotextile; 4-Materials intake area; 5-Transport road; 6-Return water tower; 7-Clarified water area. Detailed Implementation

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] It should be noted that in the description of this invention, the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not mean that the device or element must have a specific orientation, or be constructed and operated in a specific orientation.

[0019] like Figure 1 As shown, the tailings damming technology proposed in this invention to solve the problem of insufficient clarification distance includes the following steps: Step 1, Material Extraction: Use an excavator to excavate the consolidated dry tailings sand in the dry beach area of ​​the tailings dam, away from the water and close to the mountain, as dam construction material; Step 2, Transportation and Road Preparation: Use self-unloading trucks to transport dry tailings sand to the designated area in front of the dam; before operation, pave and compact the road surface with rubble and loess to form a stable equipment operation and transportation channel; Step 3, Piling and Compaction: With the help of bulldozers, the unloaded dry tailings sand is gradually pushed towards the water area of ​​the reservoir, spread out, and compacted in layers to form the basic shape of the dam. During the operation, close monitoring is required to prevent equipment from getting stuck in the wet and soft tailings or from collapsing.

[0020] Step 4, Shaping and Protection: The slope of the initially formed dam body is cut and shaped to form a wide-topped dam with specified outer slope ratio and inner slope ratio. The outer slope ratio of the wide-top dam 1 is 1:3, and the inner slope ratio is 1:2; the inner slope is the water-facing side. Geotextile 3 (350~450g / m²) was laid on the inner slope surface of the Kuandingzi Dam 1. 2 This is to prevent water seepage from causing piping.

[0021] The dam height and dry beach length are determined according to the tailings dam grade; the dam height must ensure that the difference between the beach crest and the water level is >2m, and the dry beach length is ≥100m.

[0022] Step 5, Post-construction treatment: Cover the outer slope and upper surface of the constructed wide-top dam 1 with 250-350mm thick mountain soil 2 and compact it to prevent dust. At the same time, set up water level gauges and safety warning signs on the water-facing side of the dam.

[0023] This invention mainly addresses the problem of short clarification distance at the end of upstream wet tailings dams. The core principle is to construct an artificial dry beach by building a wide-topped dam. By reconstructing the dam's safety conditions through its geometric configuration, dimensional parameters, and seepage prevention structure, the invention achieves dual protection of backwater purification and dam flood control from the perspectives of hydraulics and soil mechanics.

[0024] The inner slope ratio on the water-facing side is 1:2 (water-facing side of the dam), mainly based on the hydraulic buffering principle: the steeper inner slope shortens the depth of the open surface on the water-facing side, and when the tailings clear water flows to the dam, it gently overflows along the slope, avoiding the rapid flow from scouring the dam body and stirring up the already deposited fine tailings particles, causing secondary suspension; the clear water is evenly spread along the slope into the clear water area in front of the dam, preventing local turbulence from disturbing the sediment. The outer slope ratio on the back side is 1:3 (slope of the dam body behind the reservoir area), based on the soil mechanics principle of dam slope stability: the gentler outer slope increases the slope's self-weight resistance to sliding. After the dry tailings sand is layered and compacted for dam construction, the loose tailings particles rely on the gentler slope to improve the overall resistance to sliding and collapse, preventing the outer slope of the dam from collapsing under reservoir water level fluctuations and rainwater infiltration conditions, and ensuring the long-term structural stability of the structure.

[0025] Geotextile 3 is laid on the inner slope. The 1:2 slope ratio ensures a smooth surface and high adhesion of the geotextile 3, reducing the probability of it being suspended or torn. The slope gradient controls the seepage rate, allowing tailings water to slowly seep vertically along the geotextile, preventing fine tailings sand from penetrating the dam body and avoiding piping and internal dam hollowing. This utilizes the reverse filtration principle to achieve solid particle retention and water permeability. The outer slope is laid with topsoil 2. The 1:3 gentle slope facilitates soil adhesion and prevents erosion by rainwater. The sealed topsoil principle blocks dust generation channels from the surface tailings sand, achieving environmental dust suppression.

[0026] A 2-meter safety freeboard is reserved as a buffer capacity for torrential rains in the reservoir area during the flood season, preventing the water level from overflowing the dam crest and threatening the dam body. This meets the requirements of the tailings dam flood control freeboard specifications and eliminates the risk of dam failure. The tailings dam safety specifications use the minimum dry beach length as a key indicator for flood control. A dry beach length of ≥100m can block the direct impact of waves from the reservoir area on the dam body, improving the safety redundancy of the dam body during the flood season.

[0027] The water entering the return water tower 6 is clarified water after settling, eliminating the problem of turbidity in the return water at the source, preventing high-sand-content return water from wearing down mineral processing pipelines and clogging equipment, and stabilizing the water quality for mineral processing production. The geotextile 3 reverse filter structure on the slope inside the dam can prevent fine sand from the inside of the dam from entering the clarified water area with the seepage water, thus preventing secondary sediment pollution of the return water.

[0028] The conceptual logic of this invention is as follows: Upon discovering the shortening of the end-clarification distance, a transverse wide-topped dam is constructed to block the direct flow of water. The dam body is stabilized by optimizing the slope ratio. Safety margins are secured through parameters such as dam height and dry beach length. Simultaneously, seepage prevention and soil covering are used to achieve structural safety and environmental dust suppression for the dam. By modifying the structures, the hydrodynamic conditions of the reservoir area are altered, systematically addressing the pain points of poor water quality and inadequate flood control caused by insufficient clarification distance.

[0029] Matters not covered in this invention are common knowledge.

[0030] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A tailings damming technology to address insufficient clarification distance, characterized in that, The process includes the following steps: Step 1, Material Extraction: In the dry beach area of ​​the tailings dam, away from the water and close to the mountain, excavate the consolidated dry tailings sand as dam construction material; Step 2, Transportation and Road Preparation: Transport the dry tailings sand to the designated area in front of the dam; before operation, the road surface must be laid and compacted to form a stable equipment operation and transportation channel; Step 3, Piling and Compaction: The unloaded dry tailings sand is gradually pushed towards the water area of ​​the reservoir, spread out, and compacted in layers to form the initial shape of the dam; Step 4, Shaping and Protection: The initially formed dam body is shaped by slope trimming to form a wide-top dam with specified outer and inner slope ratios; the dam height and dry beach length are determined according to the tailings dam grade. Step 5: Post-processing.

2. The tailings damming technology for solving insufficient clarification distance according to claim 1, characterized in that: In step 4, the outer slope ratio of the wide-topped dam is 1:3, and the inner slope ratio is 1:

2.

3. The tailings damming technology for addressing insufficient clarification distance according to claim 1, characterized in that: In step 4, the dam height must ensure that the difference between the top of the beach and the water level is greater than 2m, and the length of the dry beach is greater than 100m.

4. The tailings damming technology for solving insufficient clarification distance according to claim 1, characterized in that: The inner slope of the wide-top dam is the water-facing side, and its surface is covered with geotextile to prevent water seepage from causing piping.

5. The tailings damming technology for solving insufficient clarification distance according to claim 1, characterized in that: Step 5 includes: covering the surface of the constructed wide-top dam with topsoil and compacting it to prevent dust, and setting up water level gauges and safety warning signs on the water-facing side.

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