A smelting tailings yard ecological restoration treatment method

Abstract

The present application provides a kind of smelting tailings yard ecological restoration management method, belong to ecological restoration technical field;The present application includes: the slope of tailings yard slows down and is even, and the solidified liquid is sprayed to the slope surface and condenses surface layer slag, then the anchor rod is fixed geogrid, and isolation layer is laid;Drainage system is constructed by water interception channel, drainage ditch and reservoir;Geogrid chamber is laid on the slope surface and restrains guest soil;Hydraulic spray technology is used to spray and form grass layer by mixed slurry containing germination accelerating seed, fiber, adhesive and fertilizer;Tree planting hole is excavated on the top of slope, horse path and slope foot, and tree is planted;Sprinkler pipe network is arranged for maintenance.The present application is aimed at the characteristics of smelting tailings, effectively consolidates the slope surface, eliminates geological disaster hidden danger, and creates suitable plant growth matrix, and realizes the recycling of water resources, finally reaches the purpose of stabilizing slope, quickly recovering vegetation, improving landscape and ecological environment.

Description

Technical Field

[0001] This invention belongs to the field of ecological restoration technology and relates to a method for ecological restoration and management of smelting tailings stockpiles. Background Technology

[0002] Pyrometallurgical processes generate tailings, which are piled up in smelting tailings dumps, and there is currently no disposal method. Smelting tailings are general solid waste with the following characteristics: (1) They form oxides after high-temperature smelting during the smelting process, and their chemical properties are stable; (2) Smelting tailings contain a high moisture content, and it is not easy to generate dust when dumping; (3) Smelting tailings have a relatively high specific gravity, with a specific gravity of 2.37 kg / m³. 3 It also exhibits a certain degree of crusting, which provides some resistance to wind erosion and sand fixation.

[0003] Based on the current production technology and needs, the smelting slag yard still needs to continue to pile up and compact the smelting tailings. According to the on-site investigation, the stockpiles are piled up along the outside of the tailings transport railway line, with a slope width of 40m to 50m. The stockpile on the northwest side is adjacent to the highway. The stockpiles are inconsistent with the surrounding environment and have a poor visual appearance.

[0004] Therefore, it is of great significance to conduct ecological restoration and management of tailings dumps, effectively address the environmental problems existing in smelting tailings dumps, eliminate potential geological hazards on tailings dump slopes, improve the ecological environment of tailings dump slopes, enhance the landscape effect of tailings dump areas, and realize the research and application of tailings dump ecological restoration and management technologies. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by providing an ecological restoration and management method for smelting tailings stockpiles. This method solves the problem of how to carry out ecological restoration and management of tailings stockpiles, address the environmental problems existing in smelting tailings stockpiles, and eliminate the potential geological hazards of tailings stockpile slopes.

[0006] Therefore, the present invention adopts the following technical solution: A method for ecological restoration and management of smelting tailings stockpile includes the following steps: Step 1: Reduce the slope of the tailings stockpile to 34-36° and level the slope.

[0007] Preferably, the original slope is reduced from 42° to 34° to 36°, and the slope is divided into 3 levels with an average slope ratio of 1:1.10-1.15. Each level is 14-15 meters high, and a 1.5-meter-wide horse trail is set between each level.

[0008] Step 2: Spray curing liquid onto the leveled slope to coagulate the loose slag on the surface into a binder. Use anchor bolts to fix the geogrid to the slope and lay an isolation layer.

[0009] Preferably, the anchor bolt includes a main anchor bolt and a secondary anchor bolt, with the main anchor bolt having a specification of ф18mm*230cm and the secondary anchor bolt having a specification of ф14mm*130cm.

[0010] Preferably, the anchor bolts are arranged at intervals to fix the geogrid; the anchor bolt intervals are 2 meters * 2 meters or 1.5 meters * 1.5 meters; the isolation layer is a three-layer geotextile.

[0011] Step 3: Set up intercepting channels at the top and bottom of the slope, and set up drainage ditches on the slope surface; the intercepting channels are connected to the drainage ditches, and the drainage ditches are connected to the water storage tank.

[0012] Preferably, a drainage ditch is installed every 100 meters on the slope; the connection between the intercepting ditch and the drainage ditch adopts an octagonal design to reduce erosion.

[0013] Step 4: Lay geocells on the reinforced slope to confine the imported soil.

[0014] Preferably, the geocells are made of polypropylene or other polymer composite materials, which are corrosion-resistant, UV-resistant, and conducive to plant growth.

[0015] Step 5: Mix the germinated plant seeds, water, fiber mulch, adhesive and organic fertilizer into a slurry, and use a hydraulic seeding machine to spray the mixed slurry onto the slope surface to form a grass seed layer.

[0016] Preferably, the grass seed layer is 8-11 cm thick. The plant seeds are preferably a mixture of grass species selected according to local climatic conditions.

[0017] Step 6: Dig planting holes at the top of the slope, the path, and the foot of the slope, and plant trees in the planting holes.

[0018] Preferably, the trees planted are Chinese scholar trees, with a crown width of 1-1.5 meters and a root ball diameter of 30-40 centimeters.

[0019] Preferably, the planting hole has a diameter of 0.6 meters, a depth of 0.5 meters, and a horizontal spacing of 3.0 meters; a three-layer geotextile is laid in the hole and backfilled with improved soil; wherein, the improved soil is prepared by adding 50 grams of water-retaining agent and 30 kilograms of organic fertilizer per 100 kilograms of soil.

[0020] Step 7: Install sprinkler irrigation network to irrigate and maintain the vegetation on the slope.

[0021] Preferably, the sprinkler irrigation network includes main pipes, branch pipes, and micro-sprinkler branch pipes; wherein: The main pipe is a φ80 mm PE pipe, which runs from the water storage tank to the top of the slope; Branch pipes are made of φ50 mm PE pipes and are laid along the walkway and toe of the slope; The micro-spraying branch pipes are led out from the branch pipes and arranged perpendicular to the slope.

[0022] The beneficial effects of this invention are as follows: This invention, targeting the characteristics of smelting tailings, effectively consolidates the slope surface, eliminates potential geological hazards, creates a suitable substrate for plant growth, and achieves water resource recycling, ultimately aiming to stabilize slopes, rapidly restore vegetation, and improve the landscape and ecological environment; specifically: 1. This invention reduces the potential risk of slope slippage by slowing the steep slope to 34-36° and combining multi-level slope and horse trail setting. It also forms a multi-layer reinforcement system through solidification liquid spraying, geogrid anchoring and geocell laying, which effectively consolidates the loose surface material, enhances the overall slope and its resistance to erosion and wind erosion, and completely eliminates the potential geological disaster risks. 2. This invention can create a suitable foundation for plant growth. Since the smelting tailings themselves lack the soil, nutrients and stable substrate required for plant growth, the possible adverse effects of the bottom tailings can be effectively isolated by laying an isolation layer, and a stable constraint space can be provided for the topsoil through geocells. By using improved soil backfilling and hydraulic spraying technology, a fertile, water-retaining and fixed growth substrate can be provided for plant seeds and trees, thereby overcoming the technical difficulties of directly greening tailings. 3. This invention has water-saving performance. Its drainage system not only effectively guides slope runoff and prevents erosion, but also collects and reuses rainwater, realizing the recycling of water resources and saving maintenance costs. In addition, this invention uses hydraulic spraying to mix grass seeds and selects seeds according to regional characteristics, which greatly improves the efficiency of grass planting, seedling uniformity and survival rate, and quickly forms effective vegetation cover. 4. This invention combines grass planting on the slope with tree planting on the top, walkway and foot of the slope to form a comprehensive greening surface. The sprinkler system ensures the water requirements of the vegetation, especially the initial vegetation. In addition, the ecological bags and geotextile materials selected in this invention have a long service life and the plant configuration is reasonable. This makes the restored slope not only able to achieve soil and water conservation and windbreak and dust suppression, but also significantly improve the landscape effect and make it more harmonious with the surrounding environment. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the tailings stockpile slope in Example 1; Figure 2 This is a top view of the geocell installation in Example 1; Figure 3 This is a cross-sectional view of the geocell installation in Example 1; Figure 4 This is a top view of the planting hole in Example 1; Figure 5 This is a side view of the planting hole in Example 1; Figure 6 This is a schematic diagram of the sprinkler irrigation network structure in Example 1; Figure 7This is a schematic diagram of the connection between the sprinkler irrigation network and the water storage tank in Example 1; Figure 8 This is a schematic diagram of the connection structure between the intercepting channel and the drainage ditch in Example 1. Detailed Implementation

[0024] The technical solution of the present invention will be described below with reference to the accompanying drawings and implementation methods.

[0025] The method provided by this invention is particularly suitable for the ecological restoration of slopes along tailings dumps generated by pyrometallurgical processes. The tailings are usually general solid wastes with stable chemical properties, high moisture content, high specific gravity, and a crust on the surface.

[0026] Example 1 This embodiment provides a method for ecological restoration and management of smelting tailings stockpiles, the specific steps of which are as follows: Step 1, Slope preparation and slope treatment: like Figure 1 As shown, the original slope of the tailings stockpile was reduced from 42° to 36°, with an average slope ratio of 1:1.15. A top-down construction method was adopted, with three levels of safe slope construction. The height of each slope level was 14.8 meters.

[0027] A 1.5-meter-wide walkway is set up between every two slope levels. The slope surface is manually leveled after sloping. Tools are used to flatten obvious protrusions. Shallow pits and trenches are backfilled with slag and compacted to make the entire slope surface basically flat.

[0028] Step 2, Slope reinforcement: like Figure 2 and 3 As shown, a curing liquid is prepared, which includes, by weight, the binder: planting soil: water = 1:3:6. The curing liquid is evenly sprayed onto the entire slope using a hydraulic spraying vehicle. The curing liquid penetrates and coats the loose slag particles on the surface, causing them to coagulate and form a bonding shell layer with a certain strength, thereby enhancing the wind erosion resistance and initial stability of the slope surface. Next, anchor bolts are used to tension and fix the 15mm*15mm triaxial geogrid to the slope surface that has been sprayed with curing liquid. The anchor bolts are arranged in a staggered or rectangular pattern at 2m*2m intervals; among which: The anchor bolts include main anchor bolts and secondary anchor bolts; the ratio of main anchor bolts to secondary anchor bolts is 1:2.

[0029] Specifically, the main anchor bolt has a specification of ф18 mm * 230 cm; the secondary anchor bolt has a specification of ф14 mm * 130 cm.

[0030] Finally, a three-layer geotextile is laid on the slope where the geogrid has been fixed. The geotextile serves as a waterproof layer, an alkali barrier layer, and a heat insulation layer, blocking the adverse effects of the lower waste material and providing a working surface for subsequent projects.

[0031] Step 3: Excavate drainage ditches and intercepting ditches: A drainage system is constructed on the leveled and reinforced slope. A water interception channel is excavated behind the slope crest line and in front of the slope toe line. A longitudinal drainage ditch is excavated every 100 meters along the vertical direction on the slope surface. The ends of all drainage ditches eventually flow into one or more water storage tanks to collect and store rainwater.

[0032] In this embodiment, a total of 5 drainage ditches are set up. The intercepting ditches at the top and bottom of the slope are connected to the drainage ditches on the slope surface, such as... Figure 8 As shown, the connection between the intercepting channel and the drainage ditch adopts an eight-shaped structure to smoothly guide the water flow and reduce the concentrated scouring force of the water flow.

[0033] Step 4: Laying geocells: Several geocells are laid sequentially on the slope surface where three layers of geotextile have been laid. In this embodiment, the geocells are three-dimensional honeycomb structures made of high-strength strips welded together. After anchoring them on the slope surface, topsoil is filled into the grid as planting soil.

[0034] Geocells provide effective three-dimensional lateral restraint to the filling soil, preventing it from shifting and sinking under hydraulic and gravity forces, thereby improving the stability of the overburden layer.

[0035] Step 5: Hydroseeding the grass layer: Select a variety of plant seeds suitable for the local climate and soil conditions, mix them together, and pre-germinate the seeds. Add the pre-germinated mixed seeds, water, fibrous coverings such as wood fiber or pulp, environmentally friendly adhesives, and organic fertilizers or compound fertilizers to the mixing tank of the hydraulic seeding machine in a certain proportion to form a uniform slurry.

[0036] This embodiment uses hydraulic hydroseeding technology for grass planting. The pumping system and spray gun of the hydroseeding machine are used to spray the mixed slurry evenly onto the surface of the topsoil in the geocell chamber. The hydroseeding thickness is 8-10 cm.

[0037] The sprayed material forms a cover layer on the slope, where the fibers and adhesives firmly adhere the seeds and soil to the slope and provide moisture and nutrients for seed germination.

[0038] Step 6: Greening of the horse trail and the upper and lower edges of the slope: like Figure 4 and 5As shown, trees are planted on the hilltop platform, the various levels of horse trails, and the hillside platform. Planting pits are dug manually. Specifically, the planting pits are square or round, with a diameter of 0.6 meters and a depth of 0.5 meters. The planting pits are arranged at equal intervals along the horse trails, with a tree spacing of 3 meters.

[0039] After the planting hole is dug, a three-layer geotextile is laid at the bottom and on the side walls, and the improved planting soil is backfilled into the hole. Specifically, the improved soil is prepared by mixing 50 grams of water-retaining agent and 30 kilograms of decomposed organic fertilizer into every 100 kilograms of ordinary planting soil. The mixture is thoroughly mixed to provide the trees with a water-retaining and fertile growing substrate and to further prevent the lower layer of waste material from being trapped.

[0040] When selecting Chinese scholar trees for landscaping, the seedlings should have a crown width of 1-1.5 meters. When digging, the seedlings should be dug up with a root ball, the diameter of which should be 30-40 centimeters. Place the seedlings in the planting holes, backfill with improved soil and compact it, then water thoroughly.

[0041] Step 7: Installation and maintenance of the sprinkler system: like Figure 6 and 7 As shown, the irrigation water source comes from the reservoir built in step 3, and a submersible pump is installed in the reservoir.

[0042] The sprinkler irrigation network adopts a fixed layout, including main pipes, branch pipes, and micro-sprinkler branch pipes; among which: The main pipe uses an 80 mm PE pipe, which is led out from the submersible pump outlet and extends along one side of the slope to the top of the slope; the overall direction of the main pipe can be determined according to the site topography, for example, from northwest to southeast; The branch pipes are made of φ50 mm PE pipes, which are basically perpendicular to the direction of the main pipe and are arranged at the foot of the slope, each level of the ramp and the top of the slope. In this embodiment, a total of 3 branch pipes are arranged. Micro-spray branch pipes are led out from the branch pipes and are arranged perpendicular to the slope or at a certain angle along the slope, and nozzles are installed thereon.

[0043] The sprinkler network covers the entire restoration area and is a grid-like sprinkler network. In the early stage of vegetation restoration, the sprinkler system needs to be activated regularly according to the weather and soil moisture to ensure the water required for seed germination and seedling survival. In the later stage, it can mainly rely on rainwater and a small amount of supplemental irrigation.

[0044] Example 2 This embodiment is basically the same as Embodiment 1, except for the selection of some technical parameters, which is intended to illustrate the adjustability and applicability of this method.

[0045] Step 1, Slope preparation and slope surface finishing: Reduce the slope to 34°, with an average slope ratio of 1:1.10. Divide the slope into 3 levels, with each level being approximately 14.8 meters high and the walkway being 1.5 meters wide.

[0046] Step 2, Slope reinforcement: The spacing of the anchor bolts is increased to 1.5m*1.5m to provide higher anchoring strength, which is suitable for sections with higher stability requirements or in cases with slightly poor soil quality.

[0047] Step 5, Hydroseeding: The cover layer formed by hydraulic hydroseeding is 9-11 cm thick to provide a thicker protective layer and growth substrate.

[0048] Other steps, such as step 3 drainage system, step 4 geocell laying, step 6 tree planting and greening, and step 7 sprinkler system layout, are consistent with Example 1.

Claims

1. A method for ecological restoration and management of smelting tailings stockpiles, characterized in that, Includes the following steps: Step 1: Reduce the slope of the tailings stockpile from 42-50° to 30-40°, divide it into multiple slopes, set up walkways between each slope, and level the slope surface. Step 2: Spray solidifying liquid onto the leveled slope to coagulate the surface debris, use anchor bolts to fix the geogrid to the slope, and lay the isolation layer. Step 3: Set up intercepting channels at the top and bottom of the slope, and set up several drainage ditches at intervals on the slope surface. The intercepting channels, drainage ditches and water storage tanks are connected in sequence. Step 4: Lay geocells on the reinforced slope; Step 5: Using hydraulic spraying, the mixed slurry is sprayed onto the slope surface to form a grass seed layer; the mixed slurry contains germinated plant seeds, water, fiber mulch, adhesive, and organic fertilizer; Step 6: Dig planting holes at the top of the slope, the horse trail, and the foot of the slope, and plant trees in the planting holes; Step 7: Install sprinkler irrigation network to irrigate and maintain the vegetation on the slope.

2. The method according to claim 1, characterized in that, In step 1, the slope is reduced to 34-36°, with an average slope ratio of 1:1.10-1.

15. The slope is divided into 3 levels, with each level being 14-15 meters high. A 1.5-2 meter wide walkway is set between each level.

3. The method according to claim 1, characterized in that, In step 2, the anchor rods are arranged at 1.5-2m intervals to fix the geogrid; The anchor bolts include main anchor bolts and secondary anchor bolts; wherein: the main anchor bolt has a specification of ф18 mm * 230 cm; and the secondary anchor bolt has a specification of ф14 mm * 130 cm.

4. The method according to claim 1, characterized in that, In step 2, the isolation layer consists of at least three layers of geotextile.

5. The method according to claim 1, characterized in that, In step 3, the connection between the intercepting channel and the drainage ditch adopts an eight-shaped structure.

6. The method according to claim 1, characterized in that, In step 4, the geocells are made of polypropylene or polymer composite materials.

7. The method according to claim 1, characterized in that, In step 5, the grass seed layer thickness is 8-15cm; the plant seeds used are mixed grass seeds.

8. The method according to claim 1, characterized in that, In step 6, the dimensions of the planting holes are: diameter 0.6-1m, depth 0.5-0.8m; the horizontal spacing between the planting holes is 3-4 meters. An isolation layer is laid in the planting hole, and then the soil is backfilled with improved soil.

9. The method according to claim 8, characterized in that, The soil improvement formula is as follows: add 50-60 grams of water-retaining agent and 30-40 kilograms of organic fertilizer per 100 kilograms of soil.

10. The method according to claim 1, characterized in that, In step 7, the sprinkler network includes main pipes, branch pipes, and micro-sprinkler branch pipes; the branch pipes are arranged along the walkway and the toe of the slope, and the micro-sprinkler branch pipes are arranged perpendicular to the slope.

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