Low-disturbance step-by-step guiding and discharging stabilization method and device for tailing pile body

Abstract

The invention discloses a low-disturbance step-by-step guiding and discharging stabilization method and device for a tailing pile body, and the method comprises the steps: dividing the tailing pile body into a plurality of blocks, and introducing a drainage and discharging pipe into each block; a sodium bentonite pad is laid on the surface of the tailing pile body, a soil layer is laid on the sodium bentonite pad, and iris sibirica is planted on the soil layer; the seepage liquid and the seepage acid gas in each block are collected and directionally guided and discharged through a drainage guide and discharge pipe; and a biological agent / stabilizing agent and the like are introduced into each block through the drainage guide pipe. Compared with the prior art, dead-corner-free collection and efficient directional guide and discharge of seepage liquid and seepage acid gas under the unpowered condition are achieved through the negative pressure drainage seepage liquid / gas guide and discharge technology, and meanwhile accurate control over the chemical dosage in the stabilization process is achieved through the positive pressure grouting pile body continuous stabilization technology; the problem of acid substance rebound caused by continuous acidification after neutralization of the acid tailings is solved, and heap settlement and landslide disasters induced by in-situ injection are prevented.

Description

Technical Field

[0001] This invention belongs to the field of tailings pile treatment technology, specifically relating to a low-disturbance step-by-step stabilization method and apparatus for tailings pile. Background Technology

[0002] Tailings are a product of mineral processing, specifically the portion with the lowest content of useful target components. Under current technological and economic conditions, further processing is no longer feasible, so these tailings are stockpiled for future use. However, tailings are not entirely useless waste; they often contain components suitable for other applications and can be comprehensively utilized. Therefore, tailings represent a valuable resource waiting to be tapped, and the current task of my country's mining circular economy is to develop and utilize the large quantities of long-term stockpiled tailings.

[0003] However, the current technology for addressing the problem of acidic wastewater and waste gas generated by the oxidation of metal sulfides in tailings piles, leading to liquefaction and collapse of the piles and subsequently inducing geological disasters, uses thick pebbles to construct a water- and gas-conducting reverse filter structure and employs in-situ stirring and neutralization processes such as high-pressure jetting. However, the in-situ stirring and neutralization process using high-pressure jetting and other processes has the problems of pile disturbance and triggering geological disasters, and cannot solve the problem of continuous oxidation and acidification of sulfides after neutralization, and the rebound of acidic substances.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for stabilizing tailings piles with low disturbance through stepwise drainage, so as to solve the technical problems mentioned in the background art.

[0006] To achieve one of the above objectives, the present invention provides the following technical solution:

[0007] A low-disturbance, step-by-step tailings stabilization method includes the following steps:

[0008] S100. Divide the tailings pile into several blocks, and lay a three-dimensional drainage and drainage network in each block to cover all areas of the pile.

[0009] S200. Lay a 50cm sodium bentonite mat on the surface of the tailings pile, lay a soil layer on top of the sodium bentonite mat, and plant Siberian irises on the soil layer.

[0010] S300: The seepage liquid and seepage acid gas in each block are simultaneously collected under negative pressure and directed out through the drainage pipe.

[0011] S400: Stabilizing agents, biological agents, etc. are pumped into each block through drainage pipes.

[0012] Preferably, in step S100:

[0013] Each block's drainage pipe is equipped with a solenoid valve switch, and a sensor is installed below the switch to detect the moisture content and gas pressure in the block in real time. When the sensor signal exceeds the set threshold, the opening and closing of the pipeline is automatically controlled.

[0014] Preferably, in step S400:

[0015] The biological agent is a desulfurizing bacterium, *Desulfovibrio desulfuicans*, and a *Geobacter sulfurreducens*, in a ratio of 1:1 to 1:2.

[0016] Preferably, in step S400:

[0017] The stabilizing agent is prepared by the following method:

[0018] Using ultrafine tailings, tailings from stockpiles, and industrial waste steel slag and fluorogypsum as raw materials and activators, under the alkaline activation of calcium oxide, the halogens (F) in the fluorogypsum are released. - (1.25 Å) to replace O2 with ionic radii similar to those in the silicon-oxygen tetrahedron. - (1.32 Å), accelerated hydration to form rod-shaped ettringite and intermediate AFm phase.

[0019] Preferably, the method for treating the permeate and permeate acidic gas collected in step S300 includes:

[0020] S310: Water-soluble silicates and ball mill steel slag particles are added to the seepage liquid, and then acidic gas is pumped into the seepage liquid through a nano aerator.

[0021] S311: Pass the gas-liquid mixture obtained in step 310 into the metal-rich biochar catalyst and stabilizing agent;

[0022] S312: The gas-liquid mixture obtained in step 311 is then passed into quicklime.

[0023] Preferably, in step S310:

[0024] The ratio of water-soluble silicate to ball mill steel slag particles is 5:1-10:1, and the nano-aeration time is 5-30 min.

[0025] Preferably, in step S310:

[0026] The water-soluble silicate is -SiO3. 2- or -Si2O5 2- One or two of water-soluble silicic acids.

[0027] Preferably, in step S311:

[0028] The metal-rich biochar catalyst is prepared by the following method:

[0029] Siberian iris plants were planted in the soil on the surface of the tailings pile. Metal ion nutrient solution, as well as sulfate and phosphate nutrient solution, were added to the soil. The plants were harvested after two months of cultivation.

[0030] The dried Siberian iris was washed, dried, and crushed in a 1 mmol / L hydrochloric acid solution;

[0031] The crushed Siberian iris was calcined at 900 degrees Celsius to obtain a metal-rich biochar catalyst.

[0032] Preferably, the metal ion nutrient solution includes nickel, cobalt, lead, copper, and zinc ions.

[0033] To achieve the second objective mentioned above, the present invention provides the following technical solution:

[0034] A tailings pile low-disturbance step-by-step stabilization device is constructed using the aforementioned tailings pile low-disturbance step-by-step stabilization method.

[0035] Compared with the prior art, the tailings pile stabilization method and apparatus with low disturbance stepwise discharge provided by the present invention has the following beneficial effects:

[0036] 1. Based on the gas pressure gradient model, this invention scientifically sets the pipeline distribution and negative pressure diversion intensity, which strengthens the formation of a uniformly distributed pressure gradient, realizes the collection of seepage liquid and seepage acid gas without dead angles and efficient directional drainage under non-powered conditions, and the collection and drainage efficiency of seepage water / gas inside the stockpile reaches more than 95%, reducing the load on the three-dimensional drainage system and the risk of spontaneous combustion and explosion.

[0037] 2. Based on the tailings' permeability, pollutant types, and pH variations, stabilizing agents / biological agents are continuously injected into the tailings pile through a three-dimensional pipeline network. Using a single-hole injection influence radius calculation model and an injection diffusion and transport model, the pipeline switches are controlled by solenoid valves. Automatic detection and dynamic feedback adjust injection parameters such as agent injection volume, pressure, and location. After treatment, the tailings leachate pH is 6-9, the oxidation rate of tailings metal sulfides is reduced by 61.63%-72.8%, and the heavy metal content of the leachate meets the requirements of GB5085.3. Compared to traditional in-situ neutralization and techniques, this method effectively achieves precise control of agent dosage during the stabilization process, solves the problem of acidic substance rebound caused by continuous acidification after neutralization of acidic tailings, and prevents in-situ injection-induced pile subsidence and landslide disasters.

[0038] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described in detail below. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] The beneficial effects of the present invention will be illustrated below through specific embodiments:

[0041] Example 1: Acidification Control and Stabilization Treatment of a High-Sulfur Copper Tailings Pond

[0042] (1) Layout of three-dimensional drainage and drainage network

[0043] The tailings pile was divided into several 10m × 10m treatment units. Vertical holes with depths of 8m, 12m, and 15m were drilled at the center and four corners of each unit, and inclined holes with an inclination angle of 15° were laid along the potential sliding surface of the pile. HDPE perforated pipes with filters (DN50 diameter) were installed in all drill holes and connected to a network via horizontal connecting pipes. The main pipeline used DN80 UPVC pipe, and normally closed solenoid valves were installed at the connection points of each branch pipe to the main pipeline. FDR-type moisture content sensors and piezoresistive pore gas pressure sensors were bundled and embedded on the branch pipes downstream of the solenoid valves. The system's automatic control threshold was set as follows: when any sensor detects a moisture content > 35% or a gas pressure > 5 kPa, the central control cabinet immediately commands the opening of the corresponding branch's solenoid valve.

[0044] (2) Surface sealing and ecological layer construction

[0045] Heavy machinery was used to lay a 500g / m² needle-punched sodium bentonite mat across the entire surface of the leveled tailings pile, with an overlap of at least 300mm, and the joints were sealed with bentonite waterproofing sealant. Subsequently, a 30cm thick layer of topsoil (taken from nearby farmland, pH≈6.5, organic matter content>2%) was evenly spread on the bentonite mat. Two-year-old Siberian iris seedlings were then densely planted on the topsoil surface using manual sowing, with a spacing of 20cm×20cm, resulting in a planting density of approximately 25 seedlings / m².

[0046] (3) Preparation of biological agents and stabilizing agents

[0047] The biological agent consists of desulfurizing bacteria (Desulfovibrio desulfuricans CGMCC 1.1299) and Geobacter sulfurreducens (Geobacter sulfurreducens ATCC 51573), which are inoculated into a modified Postgate C medium at a wet cell weight ratio of 1:1.5 and cultured under anaerobic conditions at 35°C until the bacterial concentration reaches 10^9 CFU / mL, thus preparing a compound bacterial agent.

[0048] The stabilizing agent is made by mixing ultrafine tailings (-200 mesh, accounting for 30%), converter steel slag (specific surface area 450m² / kg, accounting for 50%), and fluorogypsum (industrial by-product, accounting for 20%) collected on site in a weight ratio, and then feeding them into a ball mill for grinding for 60 minutes until more than 90% of the material passes through a 75μm sieve, and then sealing and storing it for later use.

[0049] (4) On-site preparation of metal-rich biochar catalysts

[0050] In the spring of the following year, the mature above-ground parts of Siberian iris from step (2) were harvested. The iris was rinsed three times with a 1 mmol / L dilute hydrochloric acid solution to remove surface contaminants, and then dried in a forced-air drying oven at 80°C to constant weight. The iris was then pulverized into 1-2 mm particles using a plant pulverizer. The pulverized biomass was evenly spread in a quartz boat, placed in a tube furnace, and high-purity N2 (flow rate 200 mL / min) was introduced as a protective gas. The temperature was increased from room temperature to 900°C at a programmed rate of 10°C / min, and then pyrolyzed at this temperature for 2 hours. After the reaction, the biochar catalyst, rich in Fe, Cu, Zn, and other metal elements, was naturally cooled to room temperature under continuous N2 purging.

[0051] Tailings pile stabilization engineering application

[0052] The remediation project focused on a severely acidified area measuring 50m × 50m within the tailings dam of a large sulfur-bearing copper mine in southern China. Pre-remediation monitoring revealed that the pH of the tailings leachate in this area was 2.8, the pyrite oxidation rate was as high as 320 mg Fe²⁺ / (kg·d), and the peak pore water pressure exceeded 15 kPa during the rainy season.

[0053] Phase 1 (Guided Drainage and Biological Regulation): A central negative pressure fan with a power of 5.5kW is started to apply a stable negative pressure of -10 kPa to the inside of the tailings through a three-dimensional guided drainage network and run continuously. Simultaneously, a diaphragm pump is used to pump the composite biological agent prepared in step (3) into the tailings through the guided drainage network at a positive pressure of 80 kPa. The total dosage is 2000L, so that the initial distribution density of the agent in the tailings reaches 10^6 CFU / g.

[0054] Second stage (chemical stabilization): One week after the addition of the microbial agent, the stabilizing agent prepared in step (3) (prepared with water at a weight ratio of 1:1.2) was injected into the tailings using a high-pressure grouting pump through the same pipeline system at a pressure of 100 kPa. The total amount of agent added was 5% of the estimated dry weight of the tailings (approximately 750 tons).

[0055] After 12 months of continuous operation of the remediation project, monitoring data showed that the average pH value inside the tailings pile stabilized at 6.8, the pyrite oxidation rate decreased to 104 mg Fe²⁺ / (kg·d), a reduction of 67.5%, the pore water pressure remained stable below 5 kPa for a long period of time, and the copper ion concentration at the representative infiltration point decreased significantly from 45.2 mg / L before the remediation to 0.8 mg / L.

[0056] Example 2: Radon pollution control and multi-stage stabilization treatment at a uranium tailings pond

[0057] (1) Layout of radon-proof composite drainage system

[0058] The tailings heap was divided into 12m × 12m grid blocks. Within each block, ground-penetrating radar was used to precisely locate radon-rich areas, followed by drilling of vertical gas-conducting pipes to a depth below the water table. The pipes were made of modified PVC (lined with an EVOH layer), which combines high density and low radon permeability. Inclined conduits were laid at a 20° angle, intersecting with the vertical pipes at depth within the heap to form a three-dimensional gas-conducting network. All main pipelines used DN100 HDPE pipes, and corrosion-resistant solenoid valves were installed on each branch. A high-precision radon concentration sensor (using alpha spectroscopy) and a soil gas pressure sensor were integrated at the valve front end. A trigger threshold was set: when the radon concentration > 10 kBq / m³ or the gas pressure > 3 kPa, the gas discharge in that area was automatically activated.

[0059] (2) Construction of multiple surface barriers

[0060] On the leveled and compacted tailings surface, a 30cm thick layer of local red clay (particle size <0.002mm, content >30%) with a compaction degree >93% is first laid as the first adsorption and retardation layer. A 500g / m² layer of sodium-based bentonite is then laid on top, with bentonite granules used to reinforce and seal the overlaps. Finally, a 40cm thick layer of topsoil (pH neutral, rich in organic matter) is laid on top, and *Pteris vittata* seedlings are planted at a spacing of 25cm x 25cm to utilize their root system for soil stabilization and uranium and radium enrichment.

[0061] (3) Preparation of radionuclide immobilization agents and functional bacterial agents

[0062] The stabilizing agent is a mixture of ultrafine tailings (25%), blast furnace slag (specific surface area 500 m² / kg, 40%), fluorogypsum (20%), and diammonium hydrogen phosphate (15%) in a weight ratio, ball-milled to a specific surface area > 500 m² / kg. The addition of phosphates aims to promote the formation of insoluble uranyl phosphate and apatite group minerals.

[0063] The biological agent is a mixture of radiation-resistant sulfate-reducing bacteria *Desulfovibrio desulfuricans* subspecies *aespoeensis* (DSM 10631) and *Bacillus sphaericus* (JG-A12) with biomineralization function, cultured at a 1:1 ratio of viable bacteria to a concentration of 10^8 CFU / mL.

[0064] (4) On-site preparation of uranium-rich biochar

[0065] Harvest the above-ground parts of the centipede grass at the end of the growing season in step (2). After rinsing with deionized water, blanch at 105℃ for 30 minutes, then dry at 80℃ to constant weight. Crush to 2-3 mm, place in a tube furnace, and pyrolyze at 750℃ under N2 protection at a rate of 5℃ / min for 3 hours. After cooling, uranium-rich biochar with high affinity for uranium is obtained, which can be used for subsequent leachate treatment.

[0066] Application of uranium tailings dam stabilization engineering

[0067] The study focused on a test area of ​​approximately 1 hectare in a decommissioned uranium tailings dam. Before remediation, the radon emission rate on the surface of the area reached 0.8 Bq / m²·s, and the U(VI) concentration in the pore water reached 30 mg / L.

[0068] Phase 1 (Gas Control and Biological Dosing): Activate the explosion-proof negative pressure fan to maintain the system at -8 kPa, efficiently collecting and discharging radon gas. Simultaneously, inject functional microbial agents deep into the tailings using a pressurization system (60 kPa), at a dosage of 15 L / m³ of tailings.

[0069] Second stage (chemical stabilization): Two weeks after the addition of microbial agent, a screw pump is used to pump the stabilizing agent slurry (water-to-solid ratio 1:1) at a pressure of 120 kPa. The amount of agent added is 6% of the dry weight of the tailings.

[0070] After 18 months of continuous treatment, monitoring data showed that the radon emission rate on the surface of the tailings pile decreased to 0.12 Bq / m²·s, a reduction of 85%; the U(VI) concentration in the pore water remained stable below 0.1 mg / L; and the in-situ direct shear test of the pile showed that the internal friction angle increased by about 5° and the cohesion increased by 20%.

[0071] Example 3: In-situ neutralization and ecological reconstruction of alkaline leachate from a bauxite red mud dump

[0072] (1) Layout of acid gas introduction and exhaust system

[0073] The red mud pile was divided into 15m × 15m rectangular units. Within each unit, vertical drainage wells with depths of 6m and 10m were arranged in a staggered pattern. Each well had a dual-channel system, one for liquid drainage and the other for gas injection / extraction. The drainage pipes were made of alkali-resistant HDPE, and the injection pipes were made of 316L stainless steel. pH and oxidation-reduction potential (ORP) sensors were integrated into the network. The control logic was as follows: when the pH of a certain area exceeded 10.5, the gas injection valve of that unit was automatically opened, introducing pretreated industrial acidic waste gas (such as scrubbed sintering flue gas).

[0074] (2) Construction of alkali-resistant coating

[0075] A 20cm thick layer of gravel (10-30mm particle size) is laid directly on the red mud surface for drainage. A 600g / m² composite geomembrane (HDPE membrane + non-woven fabric) is then laid on top as the main seepage barrier. Following this, a 50cm thick layer of topsoil (pre-acidified by mixing 30% sulfur powder and 5% ferrous sulfate) is laid. Finally, alkali-tolerant pioneer plants, Tamarix chinensis and Suaeda salsa, are planted at a spacing of 30cm x 30cm.

[0076] (3) Preparation of alkaline neutralization and stabilizing agents

[0077] The stabilizing agent uses steel slag (CaO content >40%, 35%), fluorogypsum (25%), fly ash (20%), and locally discarded acidic clay (20%) as raw materials. After all components are mixed, they are ball-milled until 80% of the particles pass through a 45μm sieve, utilizing the combined effects of the alkalinity of steel slag, the activating effect of fluorogypsum, and the acidity and ion exchange capacity of clay.

[0078] (4) Propagation of alkaliphilic bacteria

[0079] A strain of alkaliphilic bacterium, *Bacillus halodurans* BH-1, was screened and domesticated from local alkaline soil. It was cultured in modified LB medium at pH 10 at 37°C and 180 rpm until the bacterial concentration reached 10^9 CFU / mL, and then used for addition.

[0080] Application of ecological reconstruction project of red mud dump

[0081] The target area is the western part of the red mud dump of an aluminum company, where the pore liquid pH is as high as 11.2 and the total alkalinity (calculated as CaCO3) exceeds 4000 mg / L.

[0082] Phase 1 (In-situ Acidification and Ecosystem Establishment): Flue gas containing approximately 5% CO2 and 500ppm SO2 (after dust removal and cooling) was injected into the designated unit at a flow rate of 0.1 m³ / min for 2 weeks via a gas injection system. Simultaneously, alkaliphilic bacteria agent was mixed with the topsoil from step (2) and covered with the mixture, and planted vegetation was completed.

[0083] Second stage (deep stabilization): Stabilizing agent slurry (water-to-solid ratio 1.2:1) is injected into the deep red mud at a pressure of 80 kPa through the guide / injection well, with an addition amount of 4% of the dry weight of the red mud.

[0084] After 24 months of treatment, the pH of the red mud pore liquid in the area remained stable in the range of 8.5-9.0, the total alkalinity of the leachate decreased by more than 70%, the surface vegetation coverage increased from less than 10% to 80%, and the average height of tamarisk reached 1.5m.

[0085] Example 4: Fluorine pollution migration prevention and consolidation in a phosphogypsum tailings pond

[0086] (1) Layout of Fluorine Corrosion Resistant Drainage and Monitoring System

[0087] The reservoir was divided into 10m × 10m treatment units. All drainage pipe networks, including perforated pipes, connecting pipes, and main pipes, were made of polyvinylidene fluoride (PVDF) material resistant to hydrofluoric acid corrosion. A 1.5mm thick HDPE smooth geomembrane was added beneath the sodium bentonite mat to form a "membrane-mat" composite seepage-proof layer. In addition to conventional moisture content and pressure sensors, fluoride ion selective electrodes were added to monitor the fluoride concentration in pore water in real time. A warning threshold of >80 mg / L for fluoride ion concentration was set to trigger enhanced drainage.

[0088] (2) Design of fluorine-specific stabilizing agents

[0089] The stabilizing agent uses high-calcium steel slag (CaO > 45%, 40%), bauxite (Al₂O₃ > 50%, 30%), fluorogypsum (20%), and a small amount of sodium aluminate (10%) as raw materials. All components are ground together to a specific surface area > 450 m² / kg. This formulation aims to utilize the reaction of calcium and aluminum components with fluoride ions to generate calcium fluoroaluminate (such as Ca₄Al₂O₆F₂) and fluorapatite, which have extremely low solubility, thereby achieving the chemical fixation of fluoride.

[0090] (3) Construction of a dedicated leachate treatment system

[0091] The collected high-fluoride leachate ([F⁻] ≈ 150 mg / L) was first pumped into an adsorption tower filled with activated alumina (γ-Al₂O₃) for pretreatment, with the empty tower flow rate controlled at 2 BV / h. The effluent then entered a subsequent nano-aeration-metal-rich biochar-quicklime synergistic treatment system (see claims 5, 6, 7).

[0092] (4) Preparation of aluminum-rich biochar

[0093] Plants with a strong ability to accumulate aluminum (such as Miscanthus sinensis) planted on the surface of the pile were harvested and then pyrolyzed at 800°C according to the method in Example 1 to prepare aluminum-rich biochar, which was used as a supplementary adsorbent material in the leachate treatment process.

[0094] Engineering Applications of Phosphogypsum Storage Consolidation and Fluorine Pollution Control

[0095] The treatment area is the edge of a phosphogypsum storage area of ​​a phosphate fertilizer plant. The leachate in this area has a fluoride concentration as high as 150 mg / L and the pile structure is loose.

[0096] Phase 1 (Drainage and Seepage Prevention): Activate the negative pressure drainage system (-5 kPa) while closely monitoring the integrity of the composite seepage prevention layer.

[0097] The second stage (in-situ fluorine fixation): The stabilizing agent slurry (water-to-solid ratio 1:1) is injected into the reactor body at a pressure of 90 kPa using a corrosion-resistant pump. The agent dosage is 7% of the dry weight of phosphogypsum.

[0098] The third stage (leachate treatment): The collected leachate is continuously passed through a specialized treatment system.

[0099] After 12 months of treatment, the fluoride concentration in the leachate of the heap decreased to 8 mg / L, meeting the leaching toxicity limit (10 mg / L) of the "Identification Standard for Hazardous Waste". The in-situ load test of the heap showed that the bearing capacity characteristic value reached 120 kPa and the unconfined compressive strength was 1.5 MPa, achieving the dual goals of stabilization and fluoride fixation.

[0100] Example 5: Cyanide Degradation and Synergistic Stabilization in a Gold Mine Cyanide Tailings Pond

[0101] (1) Cyanide degradation enhanced drainage system

[0102] The tailings pile division and pipeline layout are based on Example 1. The key improvements are: a) integrating an ultraviolet photolysis unit into the main pipeline to pretreat hydrogen cyanide (HCN) in the extracted gas; b) adding a cyanide ion (CN⁻) selective electrode to the sensor array and setting an alarm threshold of >1 mg / L.

[0103] (2) Preparation of catalytic degradation stabilizing agents and microbial agents

[0104] The stabilizing agent is formulated with an additional 5% manganese dioxide (MnO2, catalytic activity >90%) as a cyanide oxidation catalyst in the basic formula (30% ultrafine tailings, 45% steel slag, 25% fluorogypsum).

[0105] The biological agent consists of desulfurizing bacteria, Geobacterium (ratio 1:1), and a cyanide-degrading bacterium *Pseudomonas fluorescens PCN-2 (accession number: CCTCC M 2023125) isolated from contaminated soil, which are mixed and cultured at a live bacteria ratio of 1:1:2.

[0106] (3) Integration of precious metal recycling modules

[0107] Following the initial collection tank of the negative pressure drainage system, an adsorption column filled with a strongly basic anion exchange resin (such as type D201) is connected in series. The leachate is passed through the resin column at a flow rate of 3 BV / h, selectively adsorbing and recovering [Au(CN)2]⁻ isocyanate complex ions.

[0108] (4) Multiple surface barriers

[0109] The "sandwich" covering structure of "topsoil (20cm) + sodium bentonite mat + topsoil (20cm)" is adopted. The bottom layer of topsoil is mixed with slow-release nitrogen and phosphorus fertilizer to promote plant growth, and the top layer of topsoil is used for direct planting.

[0110] Application of collaborative management of cyanide tailings ponds

[0111] The target area is a historical tailings pond of a gold mine, with a total cyanide concentration of approximately 50 mg / L in the tailings leachate and trace amounts of residual gold.

[0112] Phase 1 (Resource Recovery and Bioinoculation): The drainage system is activated to guide the initially collected high-concentration leachate to the resin column for precious metal recovery. Simultaneously, a compound microbial agent is added through the pipeline network.

[0113] Second stage (chemical oxidation stabilization): Inject slurry containing MnO2 as a stabilizing agent, with an addition amount of 5.5% of the dry weight of the tailings.

[0114] Phase 3 (Ecological Enclosure): Complete the construction of the "sandwich" cover layer and plant local suitable grasses and shrubs.

[0115] After the remediation period, the total cyanide concentration in the tailings leachate decreased to 0.3 mg / L, far below the limit (1 mg / L) stipulated in the "Technical Specification for Pollution Control of Cyanide Slag in the Gold Industry". Simultaneously, a considerable amount of gold was recovered from the resin column. The stability of the stockpile met the requirements for safe storage.

[0116] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for stabilizing tailings piles with low disturbance through stepwise drainage, characterized in that, Includes the following steps: S100. Divide the tailings pile into several blocks, and lay a three-dimensional drainage and drainage network in each block to cover all areas of the pile. S200. Lay a 50cm sodium bentonite mat on the surface of the tailings pile, lay a soil layer on top of the sodium bentonite mat, and plant Siberian irises on the soil layer. S300: The seepage liquid and seepage acid gas in each block are simultaneously collected under negative pressure and directed out through the drainage pipe. S400: Stabilizing agents, biological agents, etc. are pumped into each block through drainage pipes.

2. The method for low-disturbance step-by-step stabilization of tailings piles according to claim 1, characterized in that, In step S100: Each block's drainage pipe is equipped with a solenoid valve switch, and a sensor is installed below the switch to detect the moisture content and gas pressure in the block in real time. When the sensor signal exceeds the set threshold, the opening and closing of the pipeline is automatically controlled.

3. The method for low-disturbance step-by-step stabilization of tailings piles according to claim 2, characterized in that, In step S400: The biological agent is a desulfurizing bacterium, *Desulfovibrio desulfuicans*, and a *Geobacter sulfurreducens*, in a ratio of 1:1 to 1:

2.

4. The method for low-disturbance step-by-step stabilization of tailings piles according to claim 3, characterized in that, In step S400: The stabilizing agent is prepared by the following method: Using ultrafine tailings, tailings from stockpiles, and industrial waste steel slag and fluorogypsum as raw materials and activators, the halogens (F) in the fluorogypsum are released under the alkaline activation of calcium oxide in the steel slag. - (1.25 Å) to replace O2 with ionic radii similar to those in the silicon-oxygen tetrahedron. - (1.32 Å), accelerated hydration to form rod-shaped ettringite and intermediate AFm phase.

5. The method for low-disturbance stepwise stabilization of tailings piles according to claim 4, characterized in that, The treatment method for the collected seepage fluid and seepage acidic gas in step S300 includes: S310: Water-soluble silicates and ball mill steel slag particles are added to the seepage liquid, and then acidic gas is pumped into the seepage liquid through a nano aerator. S311: Pass the gas-liquid mixture obtained in step 310 into the metal-rich biochar catalyst and stabilizing agent; S312: The gas-liquid mixture obtained in step 311 is then passed into quicklime.

6. The method for low-disturbance stepwise stabilization of tailings piles according to claim 5, characterized in that, In step S310: The ratio of water-soluble silicate to ball mill steel slag particles is 5:1-10:1, and the nano-aeration time is 5-30 min.

7. The method for low-disturbance step-by-step stabilization of tailings piles according to claim 5, characterized in that, In step S310: The water-soluble silicate is -SiO3. 2- or -Si2O5 2- One or two of water-soluble silicic acids.

8. The method for low-disturbance step-by-step stabilization of tailings piles according to claim 5, characterized in that, In step S311: The metal-rich biochar catalyst is prepared by the following method: Siberian iris plants were planted in the soil on the surface of the tailings pile. Metal ion nutrient solution, as well as sulfate and phosphate nutrient solution, were added to the soil. The plants were harvested after two months of cultivation. The dried Siberian iris was washed, dried, and crushed in a 1 mmol / L hydrochloric acid solution; The crushed Siberian iris was calcined at 900 degrees Celsius to obtain a metal-rich biochar catalyst.

9. A method for stabilizing tailings piles with low disturbance through stepwise drainage according to claim 8, characterized in that, The metal ion nutrient solution includes nickel, cobalt, lead, copper, and zinc ions.

10. A low-disturbance, step-by-step tailings stabilization device, characterized in that, It is constructed using the low-disturbance stepwise drainage stabilization method for tailings piles as described in any one of claims 1-9.