A tailings classification and backfilling system and method for mining areas

Abstract

The application discloses a mine tailings grading filling system and a filling method, which is composed of a tailings collecting device, a grading module, a filling slurry preparation module, a conveying module and a filling module, and is designed in view of the characteristics of lead-zinc-silver mine tailings, copper-tin-silver-zinc mine tailings, heavy metal containing, complex particle size and the like. A heavy metal adsorption layer is arranged at the bottom of the collecting pool of the tailings collecting device, and a sulfide adsorbent is adopted, so that the heavy metal ions such as lead, zinc and copper in the tailings can be effectively adsorbed; the cyclone of the grading module is made of corrosion-resistant material, so that the tailings are prevented from being eroded by chemical substances. The application realizes accurate tailings grading and optimized filling material grading: the application uses a cyclone and a multi-layer vibrating screen combined grading equipment to accurately separate tailings with different particle sizes according to the characteristics of lead-zinc-silver mine tailings and copper-tin-silver-zinc mine tailings, accurately controls the particle size of the tailings by adjusting the equipment parameters, provides reasonable grading raw materials for the filling slurry preparation, and improves the compactness and stability of the filling body.

Description

Technical Field

[0001] This invention relates to the field of tailings classification and backfilling technology, specifically to a tailings classification and backfilling system and method for mining areas. Background Technology

[0002] In lead-zinc-silver and copper-tin-silver-zinc mining, tailings treatment and goaf backfilling are critical issues, and traditional tailings backfilling technologies have many drawbacks. In the tailings classification stage, most existing processes struggle to effectively classify tailings with complex particle size distributions and high heavy metal content. For example, single hydrocyclone classification methods cannot accurately separate tailings of different particle sizes, leading to unreasonable gradation of subsequent backfill materials and affecting the performance of the backfill body. Regarding backfill slurry preparation, existing technologies neglect the inhibitory effect of heavy metal ions in tailings on the hydration reaction of cementitious materials. Conventional proportions prevent cementitious materials from fully exerting their cementing effect, and the selection and use of additives lack specificity, making it difficult to improve key slurry properties. Slurry transportation also presents numerous problems. The high specific gravity and abrasiveness of tailings cause wear and tear on ordinary transportation pipelines and pumping equipment, increasing maintenance costs. Precise control of slurry flow rate, pressure, and concentration is difficult during long-distance, high-elevation-difference transportation, easily leading to pipeline blockage, slurry segregation, and other problems, affecting the continuity and stability of backfilling operations. In addition, the current backfilling process is not effective. Traditional backfilling methods cannot make full use of the characteristics of tailings with different particle sizes, resulting in poor compaction and integrity of the backfill body, increasing the risk of surface subsidence. Furthermore, the resource utilization of tailings is insufficient, wasting resources and posing a potential threat to the environment. Summary of the Invention

[0003] Therefore, the present invention provides a tailings grading and backfilling system and method for mining areas to overcome the problems of the prior art.

[0004] This invention is implemented by the following technical solution:

[0005] A tailings grading and backfilling system for mining areas includes:

[0006] Tailings classification module, filling slurry preparation module, slurry conveying module, filling module, and intelligent monitoring and control module;

[0007] The tailings grading module consists of a hydrocyclone and a multi-layer vibrating screen, used to grade the tailings according to particle size. The tailings grading module grades the tailings at three grading boundaries: 500 mesh, 400 mesh, and 300 mesh. Based on material balance analysis, a grading scheme is determined, and the daily average filling volume of the goaf (Vr), the daily required slurry filling amount (Qr), and the annual average required filling slurry amount (Qa) are calculated using the following formulas:

[0008]

[0009]

[0010]

[0011] Where Vk is the daily ore production, and Z is the utilization ratio. K is the ore weight, K1 is the loss coefficient (value range 0.95-1.05), K2 is the settling ratio (value range 1.1-1.3), and T is the filling working days;

[0012] The optimal grading particle size was determined by combining thickener torque analysis;

[0013] The filling slurry preparation module includes a mixer and an automated batching system, used to determine the slurry ratio based on experiments, to achieve unconfined uniaxial compressive strength. To measure the strength of the filling material, P is the maximum longitudinal load when the test block fails, and A is the cross-sectional area perpendicular to the loading direction.

[0014] And by measuring the water exudation rate:

[0015]

[0016] Where B is the bleeding rate, Vw is the total mass of bleeding water, W is the water consumption of the slurry, G is the total mass of the slurry and container, and Gw is the mass of the slurry.

[0017] Shrinkage rate:

[0018]

[0019] V1 is the shrinkage rate of the slurry, V2 is the volume reduced after settling, and V2 is the total volume of the raw slurry. Based on a simple volume ratio, the shrinkage rate is determined without considering the influence of the external environment on the settling. Considering the influence of heavy metal ions in the tailings on the hydration reaction of the cementitious materials, the amount of cementitious materials is increased and additives are selected to improve the slurry fluidity and the agglomeration effect of fine tailings. A mathematical model of slurry ratio and performance index is established using artificial intelligence algorithms. The ratio is continuously optimized through neural network algorithms to determine the optimal slurry ratio.

[0020] The slurry conveying module uses pipelines to transport the slurry, and the pipeline resistance is calculated using the Jinchuan formula. Estimating the critical flow velocity using the Durad formula Ensure the actual flow rate is greater than ,

[0021] The filling module transports the slurry to the underground goaf for filling.

[0022] The intelligent monitoring and control module includes a pressure sensor, a flow sensor, a wear monitoring sensor, and a PLC controller. The PLC controller is based on a PID algorithm and adjusts the pumping equipment speed and valve opening according to the real-time data from the pressure sensor, flow sensor, and wear monitoring sensor.

[0023] Preferably, in the tailings grading module, the tailings particle size is allocated according to the stress requirements of different areas of the goaf: fine-grained tailings with a particle size of less than 500 mesh are used near the top plate, and coarse-grained tailings with a particle size of more than 300 mesh are used at the bottom; the grading efficiency and dewatering effect are optimized by CFD simulation of the flow field inside the thickener.

[0024] Preferably, the filling slurry preparation module incorporates an artificial intelligence algorithm, which is a BP neural network model, and the training data comes from historical proportioning test datasets.

[0025] Preferably, the slurry conveying module is equipped with a pipe wear monitoring sensor to predict the lifespan using a wear model; wear-resistant pipe materials and wear-reducing agents are used to reduce wear, and the critical flow velocity parameters are dynamically adjusted.

[0026] Preferably, the filling module adopts a layered intermittent filling process: the bottom is filled with coarse-grained slurry to form a base layer, and fine-grained slurry is filled at intervals of a set height; the quality of the filling body is monitored in real time using ground-penetrating radar and non-destructive testing technology.

[0027] A method for graded backfilling of tailings in a mining area includes the following steps:

[0028] Step 1, Tailings Classification: Classify the tailings according to the 500 mesh, 400 mesh, and 300 mesh classification boundaries, calculate Vr, Qr, and Qa, and determine the optimal classification particle size by combining thickener torque analysis. Lay a sulfide adsorption layer at the bottom of the tailings collection pool.

[0029] Step 2, Slurry preparation: Determine unconfined compressive strength By the bleeding rate B and the sedimentation rate Determine the optimal ratio and mix thoroughly;

[0030] Step 3, Slurry conveying: Calculate pipeline resistance using the Jinchuan formula. Durand's formula for estimating critical flow velocity Ensure the actual flow rate is greater than ;

[0031] Step 4, Filling: The slurry is transported to the goaf. The online monitoring equipment obtains the lime-sand ratio (adjustable range 1:6-1:8), slurry concentration (65%-75%), and flow rate (50-150 m³ / h) in real time. When the lime-sand ratio deviates from the set value by ±5%, the automated batching system automatically adjusts the amount of cementitious material added. When the concentration is lower than 65%, the thickening equipment is started to increase the slurry consistency.

[0032] Step 5, Monitoring and Control: Real-time monitoring of pressure, flow rate, and wear data, and automatic control of pumping equipment speed and valve opening through PID algorithm.

[0033] Preferably, in step 1, the tailings particle size is allocated according to different areas of the goaf, and the thickener flow field is optimized through CFD simulation.

[0034] Preferably, in step 2, an artificial intelligence model is used to predict the optimal ratio, and automated equipment accurately dispenses the ingredients.

[0035] Preferably, in step 3, pipe wear is monitored and lifespan is predicted by using wear-resistant materials and friction-reducing agents, and the critical flow velocity parameter is dynamically adjusted.

[0036] Preferably, in step 4, a layered intermittent filling process is adopted, and the quality of the filling body is monitored by ground-penetrating radar and non-destructive testing technology.

[0037] Advantages of this invention:

[0038] Precise tailings classification and optimized backfill material gradation: This invention uses a combination of hydrocyclone and multi-layer vibrating screen to classify tailings of different particle sizes according to the characteristics of tailings from lead-zinc-silver ore and copper-tin-silver-zinc ore. The tailings particle size is precisely controlled by adjusting the equipment parameters, providing a reasonable gradation of raw materials for backfill slurry preparation and improving the compactness and stability of the backfill body.

[0039] Targeted slurry preparation to improve backfill strength: Considering the influence of heavy metal ions in tailings on the hydration reaction of cementitious materials, this invention optimizes the slurry ratio through extensive experiments, increases the amount of cementitious materials and selects additives, such as special water-reducing agents and flocculants to improve slurry fluidity and fine tailings agglomeration effect. The unconfined uniaxial compressive strength of the prepared backfill slurry is higher than that of traditional processes, meeting the support strength requirements of mining goaf areas.

[0040] Efficient and stable conveying, reducing equipment wear and maintenance costs: The conveying module selects suitable pipe materials such as ceramic-lined composite steel pipes and high-performance pumping equipment, and monitors and controls parameters such as slurry flow rate in real time to reduce pipe wear and equipment failure rate, extend pipe service life, reduce maintenance costs, ensure stable and continuous slurry conveying, and improve filling operation efficiency.

[0041] Improving resource utilization and achieving a win-win situation for both the environment and the economy: The tailings collection and pretreatment stage, along with the efficient utilization of tailings during the backfilling process, reduces pollution. Taking a lead-zinc-silver mine as an example, this invention reduces tailings emissions, recovers non-ferrous metals, lowers backfilling costs, and increases the mine's economic benefits, achieving a win-win situation for both the environment and the economy. Attached Figure Description

[0042] 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 only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a system structure diagram of the present invention;

[0044] Figure 2 This is a flowchart of the hierarchical module described in this invention;

[0045] Figure 3 This is a schematic diagram illustrating the slurry preparation and conveying principle described in this invention.

[0046] Figure 4 This is a schematic diagram of the layered filling method described in this invention;

[0047] Figure 5 This is an optional embodiment of the intelligent monitoring system architecture described in this invention. Detailed Implementation

[0048] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0049] like Figures 1-5 As shown, a tailings grading and backfilling system for mining areas includes:

[0050] Composed of a tailings collection device, a classification module, a filling slurry preparation module, a conveying module, and a filling module, this system is designed to address the characteristics of heavy metal content and complex particle size in tailings from lead-zinc-silver and copper-tin-silver-zinc mines. The bottom of the tailings collection tank is equipped with a heavy metal adsorption layer using sulfide adsorbents, which effectively adsorbs heavy metal ions such as lead, zinc, and copper from the tailings. The hydrocyclones in the classification module are made of corrosion-resistant materials to prevent erosion by chemicals in the tailings.

[0051] After settling in the collection pond, the tailings are conveyed to the grading module through the bottom sand discharge port. The magnetic separator above the belt conveyor not only removes ferromagnetic materials, but also uses eddy current separation equipment to separate non-ferrous metal particles that may be present in the tailings, thereby improving the resource recovery rate.

[0052] When the hydrocyclone is working, based on the characteristics of the relatively high density of tailings from lead-zinc-silver ore and copper-tin-silver-zinc ore (generally 2.7-4.5 g / cm³), the following formula is used:

[0053]

[0054] F c (where m is the centrifugal force, ω is the particle mass, ω is the rotational angular velocity, and r is the distance from the particle to the center of rotation) Calculate the centrifugal force, adjust the feed pressure and cyclone tube parameters to achieve efficient separation of coarse tailings.

[0055] For example, for tailings particles with a density of 3.5 g / cm³ and a particle size of 0.5 mm, rotating at an angular velocity of 100 rad / s inside a hydrocyclone, at a distance of 0.1 m from the center of rotation, their centrifugal force is:

[0056] N.

[0057] Vibrating screens utilize high-frequency vibrations generated by a vibrating motor, based on the formula:

[0058]

[0059] f represents the vibration frequency, and T represents the vibration period. Adjusting the vibration frequency and amplitude allows for precise classification of tailings with different particle sizes. For tailings from lead-zinc-silver mines and copper-tin-silver-zinc mines, the vibration frequency is generally set between 15-25Hz. Experiments have verified that this frequency range can achieve a screening efficiency of over 90% for tailings below 500 mesh, while avoiding excessive wear on the screen and ensuring effective classification.

[0060] When determining the slurry mix ratio in the laboratory, for lead-zinc-silver and copper-tin-silver-zinc mines, the influence of heavy metals in tailings on the hydration reaction of the cementitious material is considered, and the amount of cementitious material is adjusted through numerous experiments. In the unconfined uniaxial compressive strength test, the specimen size is 50mm×50mm×50mm. When the failure load P=10000N, the compressive strength is:

[0061]

[0062] In the calculation of the bleeding rate, the bleeding mass Vw = 20g, the water consumption W = 200g, the total mass of slurry + container G = 1000g (assuming the container mass is 200g), and the slurry mass Gw = G - container mass = 800g, then the bleeding rate is:

[0063]

[0064] When calculating the shrinkage rate, the volume of the raw slurry is V2 = 500 cm³. 3 After shrinkage, the volume V1 = 450 cm³ 3 Shrinkage rate:

[0065]

[0066] A mathematical model for slurry proportioning and performance indicators is established using artificial intelligence algorithms. By inputting data such as the chemical composition (e.g., lead content, zinc content) and particle size distribution of tailings from lead-zinc-silver ore and copper-tin-silver-zinc ore, the proportioning is continuously optimized through neural network algorithms to achieve precise control.

[0067] The artificial intelligence algorithm adopts a BP neural network model. The input layer includes six parameters such as tailings Pb content (%), Zn content (%), and -500 mesh particle ratio (%). The output layer is the optimal addition amount of cementitious material. The training data comes from 200 sets of lead-zinc-silver mine tailings proportion test datasets.

[0068] Specific examples are as follows: Input parameters: Pb content 1.8%, Zn content 2.3%, Cu content 0.9%, -500 mesh particle percentage 72%, -300 mesh particle percentage 88%, tailings density 3.4 g / cm³; Output result: Cementitious material addition amount 16.5% (percentage of tailings mass);

[0069] Calculate pipeline resistance using the Jinchuan formula.

[0070] The critical velocity can be estimated using the Durand formula, which is:

[0071]

[0072] Where C is a coefficient (generally taken as 0.5-1.5, determined according to the characteristics of the slurry); Δρ is the density difference between the tailings particles and the slurry liquid phase; g is the gravitational acceleration; d is the particle size; and ρ is the slurry density. For tailings from lead-zinc-silver mines and copper-tin-silver-zinc mines, assuming the particle size d = 0.3 mm, the tailings particle density ρs = 3.2 g / cm³, the slurry density ρ = 1.6 g / cm³, the coefficient C = 1, and the gravitational acceleration g = 9.8 m / s², then the critical flow velocity is:

[0073]

[0074] Pipeline sensors monitor parameters such as pressure and flow rate in real time. Based on the calculation results, the pumping equipment pressure and flow rate are adjusted to ensure stable slurry delivery. Simultaneously, by adding a special drag-reducing agent (developed specifically for the characteristics of tailings from lead-zinc-silver and copper-tin-silver-zinc mines), pipeline resistance is reduced. Furthermore, based on data from pipeline wear monitoring sensors and combined with wear models, pipeline lifespan is predicted, and critical flow velocity parameters are dynamically optimized. The calculated value ensures that the actual flow velocity is always higher than the adjusted critical flow velocity.

[0075] Layered intermittent filling is employed, with the bottom layer using coarse-grained slurry and the upper layer using fine-grained slurry. Three-dimensional laser scanning technology is used to monitor the morphology and height of the filling body in real time, and the filling strategy is adjusted based on the monitoring data to ensure dense filling of the goaf and effectively control ground pressure activity.

[0076] In practical applications:

[0077] Tailings classification principle: Hydrocyclones achieve tailings classification based on centrifugal force. Lead-zinc-silver ore and copper-tin-silver-zinc ore tailings particles of different densities and sizes move along different trajectories under centrifugal force, thus separating them. Vibrating screens use vibration to force tailings particles through the screen according to their size, achieving fine classification to meet different filling requirements.

[0078] The principle of filling slurry preparation: Based on the characteristics of tailings from lead-zinc-silver mines and copper-tin-silver-zinc mines, tailings, cementitious materials, additives, and water are rationally proportioned. The cementitious materials undergo a hydration reaction to bind the tailings particles, the additives improve the slurry properties, and the water adjusts the concentration and fluidity to prepare a filling slurry that meets the strength and construction requirements.

[0079] Slurry conveying principle: The pumping equipment provides pressure to overcome pipeline resistance, and relevant parameters are calculated based on the Jinchuan formula and Durdhausen formula to optimize the conveying process. Through monitoring and adjustment, the stable flow of slurry in the pipeline is ensured, avoiding sedimentation and blockage.

[0080] Filling principle: Layered intermittent filling, coarse-grained slurry forms the bottom layer support, fine-grained slurry fills the gaps, improves the density and integrity of the filling body, effectively supports the surrounding rock, ensures the safety of mining, and realizes the resource utilization of tailings.

[0081] Specifically, the method for graded backfilling of tailings in mining areas includes:

[0082] Tailings Collection and Pretreatment Stage: For tailings generated from lead-zinc-silver and copper-tin-silver-zinc mining, large collection ponds are set up near the tailings discharge outlets. The bottom of the collection pond is lined with inclined, wear-resistant plates at a slope of 5°-8°, allowing tailings to naturally slide to the discharge outlet in the center of the pond bottom, reducing manual cleaning workload. Corrosion-resistant guide plates are installed on the pond walls to guide the tailings flow and prevent tailings from accumulating in corners. At the inlet of the collection pond, multi-layered screens are installed to intercept large rock fragments, branches, and other debris, preventing them from entering the subsequent classification system and causing equipment blockage or damage. Simultaneously, heavy metal ion monitoring sensors installed in the collection pond monitor the concentration of heavy metal ions such as lead, zinc, and copper in the tailings in real time. Once the concentration exceeds the set range, a chemical reagent addition device is automatically activated. By adding precipitants such as sodium sulfide, heavy metal ions precipitate, reducing the impact of heavy metals in the tailings on subsequent treatment and the environment. The sulfide precipitate after heavy metal adsorption is dewatered by pressure filtration to form a filter cake, which is then solidified with cement and safely buried in a seepage-proof tailings pond.

[0083] Tailings classification stage

[0084] Preliminary classification: Multiple hydrocyclones of different specifications are used for preliminary classification. Based on the characteristics of high density and wide particle size distribution of tailings from lead-zinc-silver and copper-tin-silver-zinc mines, large-diameter hydrocyclones (e.g., 500mm-800mm) are selected to handle the tailings portion with a higher content of coarse particles, while small-diameter hydrocyclones (e.g., 150mm-300mm) are used to handle the tailings portion with a higher content of fine particles. Preliminary separation of tailings of different particle sizes is achieved by adjusting the hydrocyclone feed pressure (generally controlled at 0.1-0.3MPa), feed flow rate (determined according to tailings output and classification requirements, such as 100-300 cubic meters per hour), and the diameters of the underflow and overflow outlets. For example, for lead-zinc-silver mine tailings with a density of 3.8 g / cm³, when the feed pressure is 0.2 MPa, the feed flow rate is 200 cubic meters per hour, the underflow diameter of the large-diameter hydrocyclone is 50 mm, and the overflow diameter is 100 mm, it can effectively discharge coarse tailings with a particle size greater than 0.2 mm from the underflow port, while fine tailings with a particle size less than 0.2 mm and some water flow out from the overflow port.

[0085] Fine Classification: The tailings overflowing from the hydrocyclone enter a multi-layer vibrating screen for fine classification. The vibrating screen uses a multi-layer structure with screens of different mesh sizes, such as a 300-mesh screen in the upper layer, a 400-mesh screen in the middle layer, and a 500-mesh screen in the lower layer. By adjusting the frequency (15-25Hz) and amplitude (3-8mm) of the vibrating motor, the tailings are made to jump and tumble fully on the screen surface. Tailings with a particle size smaller than 300 mesh pass through the upper screen and enter the middle screen for further screening; tailings smaller than 400 mesh pass through the middle screen and enter the lower screen; finally, fine tailings smaller than 500 mesh pass through the lower screen, achieving precise classification. The classified tailings of different particle sizes are then transported to their respective storage silos via chutes or belt conveyors.

[0086] Filler slurry preparation stage

[0087] Proportioning Determination: In the laboratory, numerous backfill slurry proportioning tests were conducted based on the geological conditions, surrounding rock stability requirements, and tailings characteristics of the goaf areas of lead-zinc-silver and copper-tin-silver-zinc mines. Considering the potential inhibitory effect of heavy metal ions in the tailings on the hydration reaction of the cementitious materials, the amount of cementitious materials (such as cement) was appropriately increased. For example, for ordinary tailings backfilling, the ash-sand ratio might be 1:8-1:10; while for tailings from lead-zinc-silver and copper-tin-silver-zinc mines, the ash-sand ratio was adjusted to 1:6-1:8. Simultaneously, appropriate additives were added, such as polycarboxylate superplasticizers (0.5%-1.5%) to improve slurry fluidity, and flocculants (0.1%-0.3%) to enhance the agglomeration effect of fine tailings and improve sedimentation efficiency. The optimal proportion was determined by testing the unconfined uniaxial compressive strength, bleeding rate, and shrinkage rate of slurries with different proportions.

[0088] Preparation process: Tailings, cementitious materials, additives, and water are accurately measured according to a set ratio using automated metering equipment (such as high-precision electronic scales and flow meters) and then sequentially fed into a twin-shaft forced mixer. The mixer operates at 30-60 rpm for 3-5 minutes to ensure thorough and uniform mixing of all raw materials, forming a filling slurry with good fluidity and stability. During the mixing process, temperature and pressure sensors installed within the mixer are used to monitor the slurry temperature and mixing pressure in real time to ensure normal mixing operation. If the temperature is too high or the pressure is abnormal, an automatic alarm is triggered, and mixing parameters are adjusted, such as reducing the mixing speed or increasing the cooling water flow rate.

[0089] Slurry conveying stage

[0090] Pipeline Laying and Selection: The pipeline route is rationally planned based on the layout of the underground mine roadways and the location of the goaf. In horizontal roadway sections, ceramic-lined composite steel pipes are preferred due to their excellent wear resistance, effectively resisting the erosion and wear from tailings in lead-zinc-silver and copper-tin-silver-zinc mines. In vertical shaft sections, high-strength seamless steel pipes are used, and pipeline support brackets are installed to ensure stability under gravity. Pipeline connections utilize a combination of welding and flange connections to ensure sealing and strength at the joints. Removable wear-resistant bushings are installed at easily worn parts such as elbows and tees for convenient periodic replacement.

[0091] Conveying Parameter Control: A piston-type concrete pump is used as the pumping equipment. Based on the conveying distance, pipeline length, and height difference, the pumping pressure (generally 1-5 MPa) and pumping flow rate (determined according to the filling slurry production and goaf filling speed requirements, such as 50-150 cubic meters per hour) are adjusted to ensure stable slurry flow in the pipeline. Pressure sensors, flow sensors, and density sensors installed on the pipeline are used to monitor changes in slurry pressure, flow rate, and density in real time. A sudden increase in pressure or an abnormal decrease in flow rate may indicate pipeline blockage; pumping is immediately stopped, and the pipeline is cleared using a backflushing device or manual cleaning. Simultaneously, the filling slurry mix ratio is adjusted promptly based on changes in slurry density to ensure the delivered slurry quality meets requirements.

[0092] Pipeline Maintenance and Monitoring: During the transportation process, the pipe wall thickness is regularly checked using an ultrasonic thickness gauge, especially in areas prone to wear. Simultaneously, pipe leak detection sensors are installed to monitor for leaks in real time. Once a leak is detected, emergency shut-off valves are immediately activated to prevent slurry leakage, environmental pollution, and resource waste. Based on pipe wear models and actual operating data, the pipeline's service life is predicted, and materials and equipment needed for replacement are prepared in advance to ensure the continuity and stability of the transportation system.

[0093] Filling stage

[0094] Layered Interval Filling: In underground goaf areas, a layered interval filling process is adopted. First, coarse-grained slurry is transported to the bottom of the goaf through the filling pipe to form the bottom support structure. The thickness of each filling layer is determined according to the goaf height, geological conditions, and slurry properties, generally 1-3 meters. After the bottom layer of coarse-grained slurry is filled, it is allowed to settle and solidify for 1-2 days to form a stable foundation. Then, the upper layer of fine-grained slurry is filled. During the filling process, a 3D laser scanner installed near the filling pipe is used to monitor the shape and height changes of the filling body in real time to ensure uniform filling and avoid voids or insufficient filling.

[0095] Quality monitoring and control of the backfill material: During the backfilling process, samples of the backfill slurry are periodically collected from the backfilling pipe opening for on-site testing of indicators such as slump and density to ensure that the slurry performance meets design requirements. Simultaneously, pressure and displacement sensors are pre-embedded at different locations within the goaf to monitor the pressure exerted by the backfill material on the surrounding rock and changes in rock displacement in real time. Based on the monitoring data, parameters such as backfilling speed and slurry mix ratio are adjusted promptly to ensure that the backfill material effectively supports the surrounding rock and prevents excessive rock deformation that could lead to safety accidents. After backfilling is completed, the strength and integrity of the backfill material are tested by core drilling. If quality problems are found, remedial measures are taken promptly, such as secondary backfilling or reinforcement treatment.

[0096] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A mine tailings graded fill system characterized by, The application relates to a mine tailings grading and filling system and a mine tailings grading and filling method. The tailings grading module is composed of a cyclone and a multilayer vibrating screen and is used for grading full tailings according to particle sizes; the tailings grading module grades full tailings according to three grading limits of 500 meshes, 400 meshes and 300 meshes; a grading scheme is determined based on material balance analysis; daily average filling mined-out area volume Vr, daily required tailings slurry filling amount Qr and annual average tailings slurry required amount Qa are calculated; the best grading particle size is determined by combining thickener torque analysis; the dewatering rate is determined by combining the following formula: the settling rate is determined by combining the following formula: the filling module is used for conveying the tailings slurry to a mined-out area for filling; the intelligent monitoring and regulation module comprises a pressure sensor, a flow sensor, a wear monitoring sensor and a PLC controller; the PLC controller is based on a PID algorithm and adjusts the rotating speed of a pumping device and the opening degree of a valve according to real-time data of the pressure sensor, the flow sensor and the wear monitoring sensor. In the tailings grading module, tailings particle sizes are distributed according to the stress requirements of different regions of the mined-out area; fine particle size tailings with a particle size less than 500 meshes are used near the roof, and coarse particle size tailings with a particle size greater than 300 meshes are used at the bottom; the grading efficiency and dewatering effect are optimized through CFD simulation of the internal flow field of the thickener. wherein Vk is the daily production of ore, Z is the adoption ratio, is the ore weight, K1 is the loss coefficient, taking the value 0.95-1.05, K2 is the sinking ratio, taking the value 1.1-1.3, T is the filling working day; The filling slurry preparation module introduces an artificial intelligence algorithm, and the artificial intelligence algorithm is a BP neural network model; training data is derived from historical proportioning test data sets. The filling slurry preparation module includes a stirrer and an automatic batching system for determining the slurry proportioning according to the test to determine the unconfined uniaxial compressive strength The strength of the filling body is measured, P is the maximum load in the longitudinal direction when the test block is destroyed, and A is the cross-sectional area perpendicular to the loading direction. The slurry conveying module adds a pipeline wear monitoring sensor and predicts the service life by combining a wear model; wear-resistant pipeline materials and a wear-reducing agent are used to reduce wear, and the critical flow velocity parameter is dynamically adjusted. where B is the water bleed rate, Vw is the total mass of water bleed, W is the water usage of the slurry, G is the total mass of the slurry + vessel, and Gw is the mass of the slurry. The filling module adopts a layered interval filling process: coarse particle size slurry is filled at the bottom to form a base layer, and fine particle size slurry is filled after the interval height is set; the quality of the filling body is monitored in real time by using a geological radar and a nondestructive testing technology. The slurry settlement rate is V1 / V2, V1 is the reduced volume after the settlement ends, and V2 is the total volume of the raw slurry. Based on the simple volume ratio relationship, the settlement rate is determined without considering the influence of the external environment on the settlement. Considering the influence of heavy metal ions in the tailings on the hydration reaction of the cementitious material, the amount of cementitious material is increased and additives are selected to improve the flowability of the slurry and the agglomeration effect of the fine tailings. A mathematical model of the slurry proportioning and performance indicators is established using artificial intelligence algorithms, and the proportioning is continuously optimized through neural network algorithms to determine the optimal slurry proportioning. The slurry conveying module adopts pipeline to convey slurry, and the pipeline resistance is calculated by Jinchuan formula The critical flow velocity is estimated by Durand formula The actual flow velocity is ensured to be greater than , The method adopts the mine tailings grading and filling system in any one of claims 1-5 and comprises the following steps: Step 1, tailings grading: full tailings are graded according to the grading limits of 500 meshes, 400 meshes and 300 meshes, Vr, Qr and Qa are calculated, the best grading particle size is determined by combining thickener torque analysis, and a sulfide adsorption layer is laid at the bottom of a tailings collecting pool; step 2, tailings preparation: tailings are prepared according to the best grading particle size; step 3, slurry preparation: the prepared tailings are mixed with cement, fly ash and water to prepare a tailings slurry; step 4, filling: the tailings slurry is conveyed to the mined-out area, and the ash-sand ratio is obtained in real time through online detection equipment; the range of the ash-sand ratio is 1:6-1:8, the slurry concentration is 65%-75%, and the flow is 50-150 m³ / h; when the ash-sand ratio deviates from the set value by ±5%, the automatic proportioning system automatically adjusts the amount of cementitious material; when the concentration is lower than 65%, the concentration equipment is started to increase the slurry consistency; step 5, monitoring and regulation: the pressure, flow and wear data are monitored in real time, and the rotating speed of the pumping device and the opening degree of the valve are automatically regulated through the PID algorithm.

2. A mine tailings classified fill system according to claim 1, characterised in that: In step 1, tailings particle sizes are distributed according to different regions of the mined-out area, and the thickener flow field is optimized through CFD simulation.

3. A mine tailings classified fill system according to claim 2, characterised in that: In step 2, the best proportioning is predicted by using an artificial intelligence model, and the automatic equipment accurately proportioning.

4. A mine tailings classified fill system according to claim 3, characterised in that: ​ 5. A mine tailings graded fill system according to claim 4, characterised in that: ​ 6. A method of graded filling of mine tailings characterized in that, ​ ​ Step 2, Slurry preparation: Determination of unconfined compressive strength , by bleeding B and slump flow Determination of optimum proportioning, mixing uniform; Step 3, slurry transportation: calculate pipe transportation resistance by Jinchuan formula , estimate critical flow velocity by Dulaide formula , ensure actual flow velocity greater than ; ​ ​ 7. A method of graded filling of mine tailings according to claim 6, characterised by, ​ 8. A method of graded filling of mine tailings according to claim 7, characterised by, ​ 9. A method of graded filling of mine tailings according to claim 8, characterised by, In step 3, the pipeline wear is monitored and the service life is predicted, the wear-resistant materials and the friction-reducing agents are adopted, and the critical flow velocity parameters are dynamically adjusted.

10. A method of graded filling of mine tailings according to claim 9, characterised in that, In step 4, the layered interval filling process is adopted, and the filling body quality is monitored by combining the geological radar and the nondestructive testing technology.

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