Close-range multi-ore-bed potassic salt ore large-section long-strip comprehensive mechanized mining method

Abstract

The invention discloses a short-distance multi-ore-bed potassic salt ore large-section long-strip comprehensive mechanized mining method, and belongs to the technical field of potassic salt ore deposit mining. The method comprises the steps that a centralized transportation roadway is arranged on an upper head mining layer, an auxiliary transportation roadway is arranged in a stable salt rock interlayer between ore layers, and combined development is achieved; arranging large-section long strip chambers in the ore blocks along the inclination direction, and reserving permanent spacing strip pillars to maintain the stope to be stable; a chamber is cut and formed at a time by a double-arm large-mining-height mining machine, and efficient stoping is realized by matching with a continuous transportation system; multiple ore beds are mined in a coordinated mode from top to bottom in sequence, and the ore block air return way and the ore block air return way of the upper ore bed are staggered by 20 m or above so as to avoid stress superposition; a full-air-pressure ventilation system combining a press-in type and a draw-out type is constructed; natural supporting is achieved through permanent spacing strip pillars and natural top and bottom plates, safety is guaranteed through a micro-seismic and top plate monitoring system, and the goaf is backfilled with tail salt slurry to achieve green mining. According to the method, safe, efficient and high-recovery-rate mining of the short-distance multi-ore-bed sylvite ore is achieved.

Description

Technical Field

[0001] This invention relates to the field of mineral resource mining technology, specifically to a comprehensive mechanized mining method for large-section, long-strip potash mines with multiple ore layers in close proximity. Background Technology

[0002] Potash is an indispensable strategic mineral resource for ensuring agricultural production and national food security.

[0003] In regions such as Africa, a typical type of solid potash deposit is widely distributed, characterized by numerous ore layers, close interlayer spacing (i.e., "close proximity"), and large individual layer thickness. The mining of these deposits faces global technical challenges, primarily constrained by their unique engineering geological and hydrogeological conditions.

[0004] The mineral layer is easily soluble in water, and the requirements for water prevention and control are strict: Potassium salt minerals (such as potassium halite and carnallite) are extremely sensitive to fresh water. Dissolving in water can cause roadway collapse, mining instability, or even major safety accidents such as water inrush and flooding of the well.

[0005] Poor stability of the roof and floor: The immediate roof and floor of potash salt ore layers are mostly composed of salt rock or mudstone, and carnallite is prone to deliquescence, resulting in generally weak stability of the surrounding rock. Under the superimposed effect of repeated mining of multiple ore layers in close proximity, stress redistribution and concentration in the overlying strata are easily triggered, causing roof subsidence and greatly increasing the difficulty of maintaining the stope and roadways.

[0006] Existing mining methods are not adaptable enough: To maintain roof stability, traditional methods often require the creation of numerous irregular pillars, resulting in low ore recovery and uneven stress distribution in the pillars. During downward mining, the mining of lower strata disturbs the stress state of upper pillars, posing a risk of roof collapse due to large-scale ground pressure activity, making safety assurance difficult. For thick strata, traditional layered mining or small-section room-and-pillar methods are complex, with tight mining continuity, and the retreat of lower layers easily damages the upper layer's protective roof or artificial false roof, resulting in high operational risks and significant resource waste.

[0007] Bottlenecks in Continuous Transportation and Efficient Mining: Achieving long-distance, high-volume continuous transportation in potash mine tunnels presents significant challenges. Traditional mine car rail or trackless transportation methods suffer from numerous transportation links, low efficiency, high energy consumption, and large personnel requirements, making it difficult to meet the high-yield and high-efficiency demands of modern mines.

[0008] Environmental pressures are becoming increasingly apparent: the stockpiling of tailings (solid) and tailings (liquid) from mineral processing not only occupies land but also poses a potential environmental pollution hazard.

[0009] Therefore, there is an urgent need in this field to develop a new mining method specifically applicable to potash mines with multiple ore layers in close proximity, and to systematically solve key technical challenges such as one-time mining of thick ore layers, safety control of the stope roof, continuous ore transportation, collaborative mining of multiple ore layers, and improvement of resource recovery rate under the premise of strict water control. Summary of the Invention

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a comprehensive mechanized mining method for large-section long strip potash mines with multiple ore layers in close proximity.

[0011] To achieve the above objectives, the present invention provides the following technical solution:

[0012] This application provides a method for integrated mechanized mining of large-section, long strip potash deposits with multiple ore layers in close proximity, including the following steps:

[0013] The steps for the layout of the mining roadways are as follows: a centralized transport roadway is arranged in the upper first mining layer, and an auxiliary transport roadway is arranged in the stable salt rock interlayer between the upper and lower mining layers to achieve joint development; ore block return airways are arranged at intervals perpendicular to the development roadways to divide the ore body into several large ore blocks.

[0014] The steps of stope structure design are as follows: In the ore block, multiple large-section strip-shaped ore rooms are arranged along the dip of the ore layer, and continuous permanent strip-shaped ore pillars are left between adjacent ore rooms to jointly maintain the stability of the stope;

[0015] Mechanized mining and transportation steps: A double-arm mining machine with the ability to form large mining heights and large cross sections in one go is used to mine in the stope; a continuous transportation system is set up behind the double-arm mining machine to realize the continuous transportation of ore from the working face to the main transportation system;

[0016] Multi-layer coordinated mining steps: mining each ore layer in sequence from top to bottom, with the mining preparation roadway of the lower ore layer staggered from the corresponding roadway of the upper ore layer in the plane;

[0017] Goaf treatment steps: Prepare tailings slurry from the tailings and tailings produced by mineral processing, and backfill it into the goaf.

[0018] Optionally, in the stope structure design step, the width of the permanent strip pillar is determined through the following steps:

[0019] a. Based on the Mohr-Coulomb strength criterion, using the formula

[0020]

[0021] Estimate the ultimate strength of the pillar, where This represents the ultimate strength of the pillar under triaxial stress. The uniaxial compressive strength of the ore and rock. This refers to the vertical stress experienced by the pillar. This is the lateral pressure coefficient of the pillar;

[0022] b. Using the pillar safety factor formula Perform verification, among which The average stress of the pillar. For safety factor;

[0023] c. Combine numerical simulation analysis to optimize the pillar width in order to determine the final size that ensures the stability of the stope.

[0024] Optionally, in the step of laying out the mining roadways, the return airways of the ore blocks are arranged at predetermined large intervals.

[0025] Optionally, in the multi-layer coordinated mining step, when mining the lower layer, the return airway of the lower layer is staggered in orientation from the return airway of the upper layer.

[0026] Optionally, in the stope structure design step, the height of the stope is adapted to the thickness of the ore layer to achieve full-height mining in one go.

[0027] Optionally, in the mechanized mining step, the dual cutting heads of the twin-arm mining machine swing in an S-shaped trajectory in a symmetrical manner to cut the designed cross-section in one go.

[0028] Optionally, in the mechanized mining step, the continuous transport system includes a bridge transfer machine and a belt conveyor, and the tail of the belt conveyor can move forward synchronously with the advancement of the twin-arm mining machine.

[0029] Optionally, the method further includes a ventilation step: constructing a hybrid ventilation system so that fresh air enters from the auxiliary transport roadway and the central transport roadway, and after washing the working face, the polluted air is discharged through the adjacent mined-out stope as a return air channel.

[0030] Optionally, the method further includes a stability monitoring step: establishing a microseismic monitoring system and a roof dynamic detection system to monitor pillar stress and surrounding rock deformation data in real time, and feeding the data back to optimize mining parameters.

[0031] Optionally, in the goaf treatment step, the tailings slurry bleeds and solidifies within the goaf, forming a solid backfill that provides auxiliary support, while the bleed water is collected and discharged to the surface for treatment.

[0032] Compared with the prior art, this application has the following beneficial effects:

[0033] This method involves jointly arranging development roadways in the upper ore layer and stable interlayers, dividing the area into several large ore blocks, arranging large-section strip stopes within the blocks, and maintaining the stability of the stope with continuous permanent strip pillars. It employs a twin-arm mining machine with high mining height and one-time cross-section forming capability, combined with a continuous transport system to achieve efficient mining. It also coordinates the mining of multiple ore layers according to the principle of top-down and staggered arrangement, while backfilling tailings slurry into the goaf. Thus, under the premise of strict water control, it achieves safe, efficient, high-recovery, and green mining of potash ore in close proximity with multiple ore layers. Attached Figure Description

[0034] Figure 1 This is a plan view of the development method according to an embodiment of the present invention.

[0035] Figure 2 This is a cross-sectional view of the development method according to an embodiment of the present invention (corresponding to...). Figure 1 Section I-I).

[0036] Figure 3 This is a cross-sectional view of the development method according to an embodiment of the present invention (corresponding to...). Figure 1 Section II-II).

[0037] Figure 4 This is a schematic diagram of the mining area layout according to an embodiment of the present invention.

[0038] Figure 5 This is a schematic cross-sectional view of the mining area layout according to an embodiment of the present invention (corresponding to...). Figure 4 (AA section).

[0039] Figure 6 This is a schematic cross-sectional view of the mining area layout according to an embodiment of the present invention (corresponding to...). Figure 4 (BB section).

[0040] Figure 7 This is a schematic diagram of the ventilation system of the longwall mining face according to an embodiment of the present invention.

[0041] Figure 8 This is a schematic diagram of the cutting and shaping route of the mining machine according to an embodiment of the present invention.

[0042] In the attached diagram: 1-Centralized transport roadway; 2-Auxiliary transport roadway; 3-Ore block transport roadway; 4-Ore block return air roadway; 5-Ore block transport transfer roadway; 6-Connecting roadway; 7-Bottom ore bin; 8-Main shaft; 9-Mining face; 10-Double-arm mining machine; 11-Bridge transfer machine; 12-Belt conveyor; 13-Ventilator; 14-Fresh airflow; 15-Stale air; 16-Panel return air roadway; 7-Ventilation shaft. Detailed Implementation

[0043] 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.

[0044] Furthermore, in this invention, an element referred to as fixed to or disposed on another element may be directly disposed on the other element, or there may be an intermediate element. When an element is considered to be connected to another element, it may be directly connected to the other element, or there may be an intermediate element present simultaneously. The terms vertical, horizontal, left, right, and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0045] The following examples are combined Figures 1-8 This application provides a detailed description of a comprehensive mechanized mining method for large-section, long-strip potash deposits with multiple ore layers in close proximity, as provided in this application:

[0046] Example 1

[0047] The present invention will now be described in detail with reference to the accompanying drawings and the description of the embodiments.

[0048] This application provides a method for integrated mechanized mining of large-section, long strip potash deposits with multiple ore layers in close proximity, including the following steps:

[0049] The steps for arranging development roadways and preparation roadways are as follows: a centralized transport roadway 1 is arranged in the upper first mining layer, and an auxiliary transport roadway 2 is arranged in the stable salt rock interlayer between the upper and lower mining layers to achieve joint development; ore block return airways 4 are arranged perpendicular to the development roadways at intervals to divide the ore body into large ore blocks.

[0050] The steps of stope structure design are as follows: In the ore block, multiple large-section strip-shaped ore rooms are arranged along the dip of the ore layer, and continuous permanent strip-shaped ore pillars are left between adjacent ore rooms to jointly maintain the stability of the stope;

[0051] Mechanized mining and transportation steps: A double-arm mining machine 10 with high mining height and one-time section forming capability is used to mine in the stope; a continuous transportation system is set up behind the double-arm mining machine 10 to realize the continuous transportation of ore from the working face to the main transportation system;

[0052] Multi-layer coordinated mining steps: mining each ore layer in sequence from top to bottom, with the mining preparation roadway of the lower ore layer staggered from the corresponding roadway of the upper ore layer in the plane;

[0053] Goaf treatment steps: Prepare tailings slurry from the mineral processing tailings and backfill it into the goaf.

[0054] In this embodiment, taking the mining of two closely spaced potash layers I and II as an example, the average thickness is relatively large and the interlayer spacing is about 15-20 meters.

[0055] In the first step, a centralized transport roadway 1 is arranged in the I ore layer, and an auxiliary transport roadway 2 is arranged in the salt rock between the two ore layers. A block transport roadway 3 is arranged parallel to the centralized transport roadway 1 at a distance of 50m. Every 200m along the strike, a block return airway 4 is arranged from the block transport roadway 3, with a length of about 1500m, thus delineating a standard block with an area of ​​about 300,000m².

[0056] The system is connected by a connecting roadway 6: a section of ore transport transfer roadway 5 connects ore transport roadway 3 and central transport roadway 1, which is used to transfer ore to the central transport roadway 1; another section of connecting roadway 6 connects ore transport roadway 3 and auxiliary transport roadway 2, which is used to transport equipment and materials to the working face.

[0057] In the second step, the width of the mining face 9 was determined to be 8m, the height to be 7m, and the width of the strip pillar to be 12m. Numerical simulation analysis showed that this pillar width could ensure the stability of the mining area within a depth of 420m.

[0058] In the third step, a double-arm mining machine 10 is selected, with a single cutting section of 8m × 7m. A bridge-type transfer conveyor 11 and a belt conveyor 12 are connected after the mining machine 10. The ore is loaded onto the mining machine 10, transferred by the transfer conveyor 11, and then conveyed to the belt conveyor 12. As the mining machine 10 advances, one end of the belt conveyor 12 moves forward with it, extending the belt from its storage device, thus achieving continuous transport. The ore mined from the working face is loaded onto the belt conveyor 12 after passing through the mining machine 10. It then travels through the ore transport roadway 3 (belt conveyor 12), the ore transport transfer roadway 5 (belt conveyor 12), and the main transport roadway (belt conveyor 12), and after crushing, is transported to the bottom ore bin 7. Finally, it is hoisted to the surface through the main shaft 8. The annual production capacity of a single working face can reach over 1 million tons.

[0059] In the fourth step, the mining face 9 adopts a single-lane layout, utilizing the return air from adjacent mined faces. A connecting lane 6 is excavated every 150-200m between the two lanes. After the first connecting lane 6 is completed, the second connecting lane is closed. The isolated section of the mining face 9 uses a local ventilation fan 13 for forced ventilation, forming a combined forced and exhaust ventilation system. Fresh air 14 flows from the auxiliary transport lane 2 and the centralized transport lane 1 to each mined face. After cleaning the face, the waste air 15 flows through adjacent mined faces into the panel return air lane 16, and then through the panel return air lane 16 to the ventilation shaft 17 for discharge to the surface.

[0060] In the fifth step, the upper I ore layer is mined first. After the goaf stabilizes, the lower II ore layer is mined. When mining the II ore layer, a 10m safety thickness is left between it and the upper ore layer. At the same time, the return airway 4 of the II ore layer is staggered by 20m from the return airway 4 of the upper ore layer in the plane. The ventilation system utilizes the adjacent goaf strips as return air ducts to form a complete full-pressure ventilation network.

[0061] In the sixth step, the stability of the pillars is monitored over a long period using a microseismic monitoring system. Simultaneously, the tailings generated on the surface are processed into a slurry and pumped to the goaf areas of 1-2 downstream working faces for backfilling, thus achieving underground tailings disposal.

[0062] This application utilizes permanent strip pillars with scientifically calculated and simulated widths to provide a robust and continuous support system for multiple ore layers in close proximity, effectively controlling the risks of roof collapse and strata movement. Combined with a top-down mining sequence and staggered arrangement, stress concentration is avoided. Multi-system dynamic monitoring further ensures safe production.

[0063] By employing a large-scale specialized mining machine (Type 10), a large-section mining area can be formed in a single cut, enabling the full height mining of thick ore layers in one operation and reducing the number of stratification steps. The accompanying continuous transport system reduces transportation interruptions and transshipment links, significantly improving production efficiency.

[0064] Large-section strip mining reduces the amount of resources occupied by pillars, while large-scale mining at one time reduces the number of stratifications, ore loss and dilution, thereby significantly improving the overall recovery rate of mineral resources.

[0065] This method is specifically designed to address the water-soluble properties of potash ore, and its development roadway layout is particularly suitable for efficient and intensive mining under conditions of close proximity and multiple ore layers.

[0066] The tailings slurry backfilling technology for goaf areas enables underground disposal of solid waste, solves the environmental pressure, land occupation and potential risks of surface tailings storage, and realizes the integration of waste generation and treatment, which meets the requirements of green and sustainable development in the mining industry.

[0067] In one specific embodiment, in the stope structure design step, the width of the permanent strip pillar is determined through the following steps:

[0068] a. Based on the Mohr-Coulomb strength criterion, using the formula

[0069]

[0070] Estimate the ultimate strength of the pillar, where This represents the ultimate strength of the pillar under triaxial stress. The uniaxial compressive strength of the ore and rock. This refers to the vertical stress experienced by the pillar. This is the lateral pressure coefficient of the pillar;

[0071] b. Using the pillar safety factor formula Perform verification, among which The average stress of the pillar. For safety factor;

[0072] c. Combine numerical simulation analysis to optimize the pillar width in order to determine the final size that ensures the stability of the stope.

[0073] In the numerical simulation analysis, a three-dimensional geological model is established using finite element software such as FLAC3D or ANSYS. The physical and mechanical parameters of the ore layer are input, including elastic modulus, Poisson's ratio, cohesion, and internal friction angle, to simulate the distribution of mining-induced stress and the deformation behavior of the pillars. Through multiple iterative calculations, the stability indicators of the pillars under different width schemes are analyzed, such as the expansion of the plastic zone and the changing trend of the safety factor, identifying potential instability risk points. During optimization, a pillar width that meets the minimum safety factor is prioritized, typically set to 1.5-2.0, while also considering mining efficiency and resource recovery rate. Finally, the accuracy of the model is verified using field monitoring data, such as stress gauge and displacement sensor readings, to ensure long-term stability of the stope.

[0074] In one specific embodiment, during the preparation roadway layout step, the ore block return airway 4 is arranged at a predetermined large interval.

[0075] This arrangement aims to optimize ventilation and reduce stress disturbances during mining. Verified through numerical simulation, the spacing is typically set at 150-200 meters to match the pillar width optimization scheme, ensuring the pillar safety factor (F) is not less than 1.8 while improving resource recovery. In practice, iterative calculations are performed based on the ore layer's physical and mechanical parameters, such as elastic modulus and internal friction angle, to prevent the plastic zone from extending to the vicinity of the return airway. Stability is monitored in real-time using data from on-site displacement sensors.

[0076] In one specific embodiment, during the multi-layer coordinated mining step, when mining the lower layer, the return airway 4 of the lower layer is staggered in orientation from the return airway 4 of the upper layer.

[0077] In practice, this staggered arrangement aims to reduce the superposition effect of inter-layer stress. The staggered distance is determined through numerical simulation analysis, typically set at 15-20 meters, to match the optimized pillar width scheme and ensure that the safety factor φ is not less than 1.8. Iterative calculations are performed by combining the physical and mechanical parameters of the ore layer, such as elastic modulus and cohesion, to prevent the plastic zone from extending to critical areas. Furthermore, displacement sensors are used to monitor roadway deformation in real time, improving mining stability and resource recovery efficiency.

[0078] In one specific implementation, during the stope structure design step, the height of the stope is adapted to the thickness of the ore layer to achieve full-height mining in one go.

[0079] In practical implementation, the determination of the stope height needs to be combined with the physical and mechanical parameters of the ore layer, such as the elastic modulus and cohesion. Iterative calculations are performed through numerical simulation to optimize the design and prevent the plastic zone from extending to critical areas. Displacement sensors are used to monitor stope deformation in real time to ensure a safety factor. The value should be no less than 1.8, thereby improving mining stability and resource recovery efficiency.

[0080] In one specific embodiment, during the mechanized mining step, the dual-arm mining machine 10's dual cutting heads oscillate in an S-shaped trajectory in a symmetrical manner to cut the designed cross-section in one go.

[0081] The swing amplitude and frequency of the swing trajectory are optimized through numerical simulation analysis. Iterative calculations, combined with ore layer physical and mechanical parameters such as elastic modulus and cohesion, are performed to minimize stress concentration and prevent the plastic zone from extending to critical areas. Simultaneously, displacement sensors are used to monitor the cutting head's movement in real time, dynamically adjusting the swing parameters to ensure a safe operating factor. The value should be no less than 1.8, thereby improving cutting accuracy and mining efficiency.

[0082] In one specific embodiment, in the mechanized mining step, the continuous transport system includes a bridge transfer machine 11 and a belt conveyor 12, the tail of which can move forward synchronously with the advancement of the twin-arm mining machine 10.

[0083] This synchronous forward movement mechanism is implemented through a hydraulic control system, ensuring close coordination between the transportation system and the mining progress, reducing downtime and improving overall operational efficiency. Simultaneously, displacement sensors monitor the tail section's position in real time, dynamically adjusting the forward movement speed to prevent equipment jamming or stress exceeding limits due to undulating ore layers. Numerical simulation analysis of the ore layer's physical and mechanical parameters optimizes the conveyor's extension and retraction amplitude and frequency to minimize disturbance to the surrounding rock mass and prevent the plastic zone from expanding to critical areas. Furthermore, the bridge-type transfer conveyor 11 efficiently transfers the cut ore to the belt conveyor 12, coordinating its actions with the automatic control system to ensure a high safety factor. It is always kept at a level of 1.8 to ensure mining stability and maximize resource recovery.

[0084] In one specific embodiment, the method further includes a ventilation step: constructing a hybrid ventilation system so that fresh airflow 14 enters from the auxiliary transport roadway 2 and the central transport roadway 1, and after washing the working face, the polluted air 15 is discharged through the adjacent mined-out stope as a return air channel.

[0085] This hybrid ventilation system employs a combined axial-flow main fan and local ventilation fans 13 to ensure that airflow uniformly covers the working face at a velocity of not less than 0.5 m / s, effectively diluting and expelling harmful gases and dust. The airflow path is precisely controlled through dampers and air walls. Combining geological parameters of the ore layer, such as permeability and fracture rate, computational fluid dynamics simulations are used to optimize airflow distribution, preventing the stagnation of polluted air 15 or short-circuiting of fresh air 14. Simultaneously, a gas sensor network is installed in the return air duct to monitor CO, H2S concentrations, and temperature in real time. Furthermore, a stress distribution model is used to assess the stability of the mined-out stope, preventing rock mass instability during the return air process and maintaining a safety factor Fs ≥ 1.8. Periodic ventilation efficiency analysis is used to optimize system operating parameters to improve energy utilization and mining continuity.

[0086] In one specific embodiment, the method further includes a stability monitoring step: establishing a microseismic monitoring system and a roof dynamic detection system to monitor pillar stress and surrounding rock deformation data in real time, and feeding the data back to optimize mining parameters.

[0087] In the microseismic monitoring system, a high-sensitivity sensor array is deployed to cover key mining areas, capturing rock fracture signals in real time. A three-dimensional positioning algorithm is used to analyze the spatiotemporal distribution of microseismic events and predict potential instability areas. The roof dynamic monitoring system uses fiber optic grating sensors and laser rangefinders to continuously monitor roof subsidence and fracture propagation speed. Combined with pillar strain gauge data, it generates a surrounding rock deformation trend map. The collected data is transmitted to the central control unit via an industrial IoT platform. Machine learning models such as support vector machines or random forests are used to identify abnormal patterns. When the deformation rate exceeds a preset threshold (≥0.5 mm / h) or the cumulative microseismic energy exceeds a critical point, an early warning mechanism is automatically triggered. The feedback mechanism includes dynamically adjusting mining parameters: for example, optimizing stope advance speed and pillar size based on real-time stress data to ensure that the stress redistribution in the surrounding rock is controlled within an elastic range. Simultaneously, the ventilation system is linked to adjust airflow pressure, ultimately achieving a mining efficiency increase of over 20% while maintaining a safety factor Fs≥1.8. Furthermore, the system periodically generates stability assessment reports and iteratively optimizes the monitoring algorithm based on historical data, enhancing its adaptability to the interactive effects of multiple ore layers.

[0088] In one specific embodiment, during the goaf treatment step, the tailings slurry bleeds and solidifies within the goaf, forming a solid backfill that provides auxiliary support, while the bleed water is collected and discharged to the ground for treatment.

[0089] Furthermore, this consolidation process accelerates the separation of seepage water by controlling the concentration and temperature of the tailings slurry, ensuring that the backfill reaches its design strength (≥1.0 MPa) within 7 days. This effectively shares the load on the pillars and reduces the risk of roof deformation. Simultaneously, the collected seepage water is pumped to the surface through an underground water collection system. After treatment in sedimentation tanks and filtration devices, a portion is reused, achieving resource recycling and reducing wastewater discharge. This mechanism not only improves the stability of the goaf but also dynamically adjusts backfill parameters based on real-time data from the microseismic monitoring system, ensuring the synergistic optimization of surrounding rock stress balance and mining safety.

[0090] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0091] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A comprehensive mechanized mining method for large-section, long-strip potash deposits with multiple ore layers in close proximity, characterized in that: Includes the following steps: The steps for the layout of the mining roadway are as follows: a centralized transport roadway (1) is arranged in the upper first mining layer, and an auxiliary transport roadway (2) is arranged in the stable salt rock interlayer between the upper and lower mining layers to achieve joint development; a block return airway (4) is arranged perpendicular to the development roadway at intervals to divide the ore body into several large blocks. The steps of stope structure design are as follows: In the ore block, multiple large-section strip-shaped ore rooms are arranged along the dip of the ore layer, and continuous permanent strip-shaped ore pillars are left between adjacent ore rooms to jointly maintain the stability of the stope; Mechanized mining and transportation steps: A double-arm mining machine (10) with the ability to form a large mining height and a large cross section at one time is used to mine in the stope; a continuous transportation system is set up behind the double-arm mining machine (10) to realize the continuous transportation of ore from the working face to the main transportation system; Multi-layer coordinated mining steps: mining each ore layer in sequence from top to bottom, with the mining preparation roadway of the lower ore layer staggered from the corresponding roadway of the upper ore layer in the plane; Goaf treatment steps: Prepare tailings slurry from the tailings and tailings produced by mineral processing, and backfill it into the goaf.

2. The method according to claim 1, characterized in that, In the aforementioned stope structure design step, the width of the permanent strip pillar is determined through the following steps: a. Based on the Mohr-Coulomb strength criterion, using the formula: ； Estimate the ultimate strength of the pillar, where This represents the ultimate strength of the pillar under triaxial stress. The uniaxial compressive strength of the ore and rock. This refers to the vertical stress experienced by the pillar. This is the lateral pressure coefficient of the pillar; b. Using the pillar safety factor formula: Perform verification, among which The average stress of the pillar. For safety factor; c. Combine numerical simulation analysis to optimize the pillar width in order to determine the final size that ensures the stability of the stope.

3. The method according to claim 1, characterized in that, In the mining preparation roadway layout step, the ore block return airway (4) is arranged at a predetermined large interval.

4. The method according to claim 1, characterized in that, In the multi-layer coordinated mining process, when mining the lower layer, the return airway (4) of the lower layer is staggered from the return airway (4) of the upper layer in terms of orientation.

5. The method according to claim 1, characterized in that, In the aforementioned stope structure design step, the height of the stope is adapted to the thickness of the ore layer in order to achieve full-height mining in one go.

6. The method according to claim 1, characterized in that, In the mechanized mining step, the dual-arm mining machine (10) has two cutting heads that swing in an S-shaped trajectory in a symmetrical manner to cut the designed cross section in one go.

7. The method according to claim 1, characterized in that, In the mechanized mining step, the continuous transport system includes a bridge transfer machine (11) and a belt conveyor (12), and the tail of the belt conveyor (12) can move forward synchronously with the advancement of the double-arm mining machine (10).

8. The method according to claim 1, characterized in that, The method also includes a ventilation step: constructing a hybrid ventilation system so that fresh air (14) enters from the auxiliary transport roadway (2) and the central transport roadway (1), and after washing the working face, the polluted air (15) is discharged through the adjacent mined-out stope as a return air channel.

9. The method according to claim 1, characterized in that, The method also includes a stability monitoring step: establishing a microseismic monitoring system and a roof dynamic detection system to monitor pillar stress and surrounding rock deformation data in real time, and feeding the data back to optimize mining parameters.

10. The method according to claim 1, characterized in that, In the goaf treatment step, the tailings slurry bleeds and solidifies within the goaf, forming a solid backfill that provides auxiliary support, while the bleed water is collected and discharged to the surface for treatment.

Images