Mining method of wheel bucket excavator in alpine region

Abstract

The invention discloses an alpine region wheel bucket excavator mining method, which can improve the mining efficiency of a wheel bucket excavator by designing a proper mining belt width, and solves the problems that in the background technology, the existing alpine region wheel bucket excavator is easily influenced by the mining belt width when working in winter; the leveling frequency of the working face and the moving frequency of the sealing-tape machine are increased, and the mining efficiency of the wheel bucket excavator is low. According to the main technical scheme, the wheel bucket excavator mining method in the alpine region comprises the steps that a mine region is divided into a plurality of mining sub-regions; determining the slicing form and the operation form of the wheel bucket excavator according to the rock-soil layer structure performance of the excavation subarea; the layering height and the slope angle of the working face step of the excavation sub-area are determined, and the excavation belt width of the wheel bucket excavator on the working face step is determined according to the layering height and the slope angle; and the working face steps are excavated through the wheel bucket excavator. The device is mainly used for mine operation in alpine regions.

Description

Technical Field

[0001] The present invention relates to the technical field of mine mining, and in particular to a mining method using a bucket wheel excavator in high-altitude cold regions. Background Art

[0002] Bucket wheel excavator is an important equipment that completes mining work in the continuous mining process of mining, transportation and drainage. It is mainly used for large-scale projects with large mining volume and long service life. It is particularly suitable for engineering fields such as open-pit mines and large earthwork projects. Bucket wheel excavator is generally composed of three parts: bucket wheel machine, transfer machine and connecting bridge. It is rotated by the bucket wheel installed at the front end of the boom, and the buckets around the bucket wheel take turns to dig out the stripping materials or mineral products. Since the alpine areas are high altitude and high latitude areas with low temperature and lack of oxygen all year round, traditional mining technology is not easy to implement. Therefore, it is necessary to use large-scale mining machinery such as bucket wheel excavators to improve mining efficiency.

[0003] When operating on an end-of-face mining surface, existing bucket wheel excavators require a bulldozer to level the working surface after each excavation to ensure smooth operation. Therefore, a properly designed excavation belt width can influence the frequency of surface leveling and the number of belt conveyor relocations, further impacting the bucket wheel excavator's overall mining efficiency. Existing technologies lack a comprehensive method for determining excavation belt width, often relying on empirical judgment and decision-making. This increases mining uncertainty and reduces mining efficiency. Summary of the Invention

[0004] In view of this, in order to solve at least one of the above-mentioned technical problems, the present invention provides a mining method for a bucket wheel excavator in high-altitude and cold areas. By designing a suitable mining belt width, the mining efficiency of the bucket wheel excavator can be improved, which solves the problem in the above-mentioned background technology that the existing bucket wheel excavators in high-altitude and cold areas are easily affected by the mining belt width during winter operations, resulting in an increase in the frequency of working surface leveling and the number of belt conveyor relocations, resulting in low mining efficiency of the bucket wheel excavator.

[0005] To achieve the above objectives, the present invention mainly provides the following technical solutions:

[0006] The present invention provides a mining method using a bucket wheel excavator in high-altitude and cold regions, the method comprising:

[0007] Divide the mining area into multiple mining sub-areas;

[0008] Determine the slicing form and operation mode of the bucket wheel excavator according to the structural properties of the rock and soil layers in the mining sub-area;

[0009] Determine the layer height and slope angle of the working face step in the mining sub-area, and determine the mining zone width of the bucket wheel excavator on the working face step based on the layer height and slope angle;

[0010] The working face steps are excavated using a bucket wheel excavator.

[0011] The step of dividing the mine area into multiple mining sub-areas includes:

[0012] A predetermined number of trenches in the mining area is determined, and the predetermined number of trenches are excavated in the mining area, where mining sub-areas are formed between adjacent trenches, and the area difference between different mining sub-areas is less than a threshold.

[0013] The depth of the trench is 1.5m-2m, and the depth of the trench is greater than the thickness of the frozen soil layer distributed on the top layer of the mining sub-area.

[0014] The excavation of a predetermined number of trenches in the mining area includes:

[0015] Dig trenches, and for each trench, evenly cover the soil layer obtained from the trenching on the top of the frozen soil layer to form a covering soil layer with a thickness of 0.5m-1m.

[0016] Among them, the slicing forms include vertical slicing and horizontal slicing;

[0017] The slicing form of the bucket wheel excavator is determined according to the structural properties of the rock and soil layer in the mining area, including:

[0018] The rock and soil layers in the mining area are sampled to obtain the mechanical properties of the rock and soil layers. The slicing form of the bucket wheel excavator is determined based on the mechanical properties of the rock and soil layers. The mechanical properties of the rock and soil layers include the hardness and thickness of the rock layers.

[0019] Among them, the layer height is 13m-15m.

[0020] Among them, determining the slope angle of the working surface step includes:

[0021] Obtaining the working parameters of the bucket wheel excavator, including the bucket wheel arm swing angle and the bucket wheel free cutting angle;

[0022] Determine the slope angle α to satisfy: And α≤δ;

[0023] in, It is the excavation radius of the top layer of the working face step. is the excavation radius of the lowest layer of the working face step, φ1 is the swing angle of the bucket wheel arm toward the inside of the step when excavating the uppermost layer of the working face step, θ is the free cutting angle of the bucket wheel in the horizontal section, δ is the free cutting angle of the bucket wheel in the vertical section, and H is the layer height.

[0024] The mining zone width of the bucket wheel excavator in the mining sub-area is determined according to the layer height and the slope angle, including:

[0025] According to the excavation radius of the uppermost layer of the excavation working surface and the excavation radius of the lowest layer of the excavation working face step Get the maximum digging radius of a bucket wheel excavator

[0026] The width of the mining zone A is calculated according to the following formula:

[0027]

[0028] Among them, φ1 is the swing angle of the bucket wheel arm toward the inner side of the step when excavating the uppermost layer of the working face step, φ2 is the swing angle of the bucket wheel arm toward the side of the goaf when excavating the lowermost layer of the working face step, H is the layer height, and α is the slope angle.

[0029] Among them, the excavation operation of the working face step is carried out by a bucket wheel excavator, including:

[0030] Using a bucket wheel excavator, excavation is started on at least the uppermost layer of the current mining sub-area according to the layer height, slope angle and mining zone width, and the rear discharge port of the bucket wheel excavator is equipped with a vehicle to load and unload materials;

[0031] After completing the excavation operation of the lowest layer in the current mining sub-area, the bucket wheel excavator is mobilized to repeat the operation on the next mining sub-area.

[0032] Among them, the operation form adopted for the working face steps is the end mining working face operation method.

[0033] This invention proposes a bucket-wheel excavator mining method for high-altitude, cold regions. This method uses trenching to divide and plan the mining area, dividing the overall project into multiple sub-projects. This facilitates efficient scheduling and construction progress. Furthermore, the method selects appropriate excavation slicing patterns based on the structural properties of the rock and soil layers in each mining sub-region, further improving construction efficiency. Designing appropriate excavation belt widths for the working face steps in each mining sub-region effectively reduces the frequency of working face leveling and belt conveyor relocation, thereby increasing the bucket-wheel excavator's operating time and improving mining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart of a bucket wheel excavator mining method in a high-altitude cold region provided by an embodiment of the present invention;

[0035] Figure 2 A schematic structural diagram of a mining area from a first perspective in which the bucket wheel excavator mining method for high-altitude cold regions provided by an embodiment of the present invention is applied;

[0036] Figure 3 A schematic diagram of the cross-sectional structure of a mining area at a second viewing angle, in which the bucket wheel excavator mining method for high-altitude cold regions provided by an embodiment of the present invention is applied;

[0037] Figure 4 A schematic diagram of a cross-sectional structure of a step on a working surface in a mining sub-area of a mine area, at a first viewing angle, to which the bucket wheel excavator mining method for alpine regions provided by an embodiment of the present invention is applied;

[0038] Figure 5 A structural schematic diagram of the upper working face steps of the mining sub-area of the mining area in which the bucket wheel excavator mining method in the high-altitude cold region provided by an embodiment of the present invention is applied at a second perspective.

[0039] In the figure: 1. Mining area; 2. Trenching; 3. Mining sub-area; 4. Frozen soil layer; 5. Overburden layer; 6. Working face step; 7. Bucket wheel. DETAILED DESCRIPTION

[0040] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation method, structure, characteristics and effects of the bucket wheel excavator mining method in high-cold areas proposed by the present invention are described in detail below in combination with the accompanying drawings and preferred embodiments.

[0041] like Figure 1 As shown, an embodiment of the present invention provides a mining method for bucket wheel excavators in high-altitude cold regions, comprising:

[0042] S1. Divide the mining area 1 into multiple mining sub-areas 3.

[0043] like Figure 2 As shown, a predetermined number of trenches 2 is determined for mining area 1. These trenches 2 are excavated within mining area 1, forming mining sub-areas 3 between adjacent trenches 2. The difference in area between different mining sub-areas 3 is less than a threshold, or in other words, several similar mining sub-areas 3 are formed. Theoretically, the best results are achieved if all mining sub-areas 3 are identical. For example, the calculation of the mining belt width A, for example, for each mining sub-area 3, can be omitted. However, in practice, due to topographical constraints, the calculation of the mining belt width A may vary between mining sub-areas 3. Therefore, the application of the mining belt width A to all or some mining sub-areas 3 can be determined based on actual conditions.

[0044] Trenching 2 is crucial for winter, as surface soil or ore layers freeze and become significantly harder. Direct excavation is energy-intensive and inefficient. Pre-excavating trenches, however, separate the frozen soil from the unfrozen soft soil, enabling efficient and continuous operation of the bucket wheel excavator and reducing wear on the bucket and mechanical structure. Furthermore, in winter, when days are short and nights are long, operating time is limited. Pre-excavating trenches can segment the mining area, allowing for centralized processing of frozen areas while simultaneously advancing unfrozen areas, effectively shortening the overall construction period. Furthermore, trenching also opens up transportation channels to ensure material delivery, while increasing the thickness of the unfrozen soil below to insulate and prevent freezing.

[0045] The depth of the trench 2 can be set according to actual conditions. The depth of the trench 2 is greater than the thickness of the frozen soil layer 4 distributed on the top layer of the mining sub-area 3. For example, the depth of the trench 2 is 1.5m-2m.

[0046] The specific steps of excavating a predetermined number of trenches 2 in the mining area 1 are as follows: excavating trenches 2, such as Figure 3 As shown, for each trench 2 , the soil layer obtained by digging the trench 2 is evenly covered on the top of the frozen soil layer 4 to form a covering soil layer 5 .

[0047] The covering layer 5 can increase the thickness and coverage of the frozen soil layer 4, and can reduce the problem of further freezing of the rock and soil layer below the frozen soil layer 4. The thickness of the covering layer 5 is 0.5m-1m, which ensures that the rock and soil layer is not easy to freeze and avoids excessively increasing the construction burden.

[0048] S2. Determine the slicing mode and operation mode of the bucket wheel excavator according to the structural properties of the rock and soil layer in the mining sub-area 3.

[0049] Slicing methods include vertical slicing and horizontal slicing. In the vertical slicing method, the bucket wheel peels off the rock and soil in layers (from top to bottom or bottom to top) in a direction perpendicular to the ground. Its motion trajectory is fixed or slightly pitched by the bucket wheel arm. The equipment advances longitudinally along the mining face, with the bucket wheel's axis of rotation perpendicular to the ground, and the cutting path forms a vertical stepped section. Vertical slicing mining process: The bucket wheel cuts in from the top or bottom of the mining face and cuts a single layer of rock and soil in a vertical direction. After each layer is cut, the entire equipment moves forward a certain distance to start cutting the next layer. In the horizontal slicing method, the bucket wheel peels off the rock and soil laterally in a direction parallel to the ground. Its motion trajectory is the bucket wheel arm swinging horizontally, and the equipment moves horizontally along the mining face. The bucket wheel's axis of rotation is parallel to the ground, and the cutting path forms a horizontal continuous section. Horizontal slicing mining process: The bucket wheel cuts in from one side of the mining face and advances horizontally to the other side. After completing a single layer of cutting, the bucket wheel arm is lowered to a certain height to proceed to the next layer of horizontal cutting.

[0050] The slicing form of the bucket wheel excavator is determined according to the structural properties of the rock and soil layer in the mining sub-area 3, including: sampling the rock and soil layer in the mining sub-area 3, obtaining the mechanical properties of the rock and soil layer, and determining the slicing form of the bucket wheel excavator according to the mechanical properties of the rock and soil layer, where the mechanical properties of the rock and soil layer include rock layer hardness and rock layer thickness.

[0051] Specifically, rock and soil layer sampling and testing were performed to analyze the mechanical properties of the rock and soil layers in different mining sub-areas 3. Vertical slicing was used to mine softer rock and soil and ore layers, particularly thin ore layers, where the bucket wheel consumes less power to lift the material. Horizontal slicing was used to mine harder rock and soil and ore layers, where the bucket wheel crushed the material during excavation, consuming more power.

[0052] The mining parameters are designed based on the rock and soil hardness data, including:

[0053] 1) Soft soil and loose rock: The Proctor hardness f is 0.5-1.5. The soil structure includes sand, humus and wet clay, which makes the cutting resistance low. The vertical slice thickness of the excavator is designed to be 1.5m-3m, which is suitable for rapid advancement.

[0054] 2) Medium-hard rock: The Pugh hardness f is 2-6, including weathered limestone, marl, etc. The excavator needs to be designed by increasing the bucket tooth density or reducing the horizontal slice thickness, usually controlled at 1m-2m to balance efficiency and wear;

[0055] 3) Hard rock and extra-hard rock: For rocks with a Procter & Gamble hardness f of 6-20, including granite, basalt, quartzite, etc., the horizontal slice thickness of the designed excavator needs to be reduced to 0.5m-1m, and a high-strength bucket tooth design should be used to cope with high cutting resistance;

[0056] The mining parameters are designed based on the rock and soil thickness data, including:

[0057] 1) Slice thickness selection principle: For soft rock and soil, thicker slices of about 2m-3m are selected to improve excavation efficiency. For hard rock, thin slices of about 0.5m are selected to reduce instantaneous load, bucket wheel wear and energy consumption.

[0058] 2) After freezing in winter, the soil hardness increases to about 2-3 times the original hardness value (the f value increases by about 1.5-4). At this time, it is necessary to dig trenches in advance and then break the frozen layer, and adjust the slice thickness to 70%-80% of the normal thickness value.

[0059] S3. Determine the layer height and slope angle of the working face step 6 of the mining sub-area 3, and determine the mining zone width A of the bucket wheel excavator on the working face step 6 according to the layer height and slope angle.

[0060] like Figure 4-5 As shown, each mining sub-area 3 is designed with a working face step 6. The working face step 6 is stepped, and stratification refers to the division of steps, with each step being called a layer. During mining, the bucket wheel 7 of the bucket wheel excavator operates on the working face step 6, using an end-to-end mining method. The layer height is 13-15 meters, which is suitable for most bucket wheel excavators.

[0061] The working face step 6 is designed as a layered structure to facilitate mining operations. The end-mining working face operation mode requires a smaller working face operation space and does not occupy much flat plate width, which can reduce the production stripping ratio and improve mining efficiency.

[0062] In one embodiment, determining the slope angle of the working surface step 6 includes: obtaining working parameters of the bucket wheel excavator, the working parameters including the bucket wheel arm swing angle and the bucket wheel free cutting angle;

[0063] Determine the slope angle α to satisfy: And α≤δ;

[0064] in, is the excavation radius of the uppermost layer of the excavation working face step (6), is the excavation radius of the lowest layer of step 6 of the working surface, φ1 is the swing angle of the bucket wheel arm toward the inside of the step when excavating the uppermost layer of step 6 of the working surface, θ is the free cutting angle of the bucket wheel in the horizontal section, δ is the free cutting angle of the bucket wheel in the vertical section, and H is the layer height.

[0065] Design and design the top layer excavation radius separately The excavation radius of the lowest layer Its functions include:

[0066] 1) Adapting to the difference in layered resistance:

[0067] The upper layer has high resistance: The uppermost layer usually contains permafrost, hard rock or weathering crust, which has high compressive strength (higher Proctor hardness coefficient f). By reducing the excavation radius of the upper layer, the bucket wheel cutting force can be concentrated, and the increased pressure per unit area can effectively crush the hard rock;

[0068] The lower layer has low resistance: the lower layer is mostly unfrozen soft soil or loose cover layer (Praeter hardness coefficient f value is 0.5-1.5), with low cutting resistance. By increasing the lower layer excavation radius, the single cutting volume can be increased, thereby increasing the mining output per unit time;

[0069] 2) Reduce the impact of dynamic loads on equipment and balance torque requirements

[0070] The use of a small radius in upper layer operations can shorten the lever arm between the bucket wheel and the center of rotation, reduce the overturning moment of the equipment, and enhance stability. In addition, when using a small radius to cut hard rock, the bucket wheel speed can be appropriately reduced to reduce the frequency of collision between the bucket teeth and hard rock, reduce the wear rate, and thus extend the life of the bucket teeth.

[0071] Although the lower layer operation adopts a large radius to increase the lever arm, the lower layer cutting force F is small and the overall torque is controllable. In addition, when cutting soft rock, the large radius is combined with a high speed to use centrifugal force to quickly throw the material, which can effectively reduce adhesion and blockage.

[0072] 3) The top layer is excavated with a small radius to form a steep section, which can reduce the excavation volume and retain more original rock support. The lower layer is excavated with a large radius to form a gentle slope section, which can increase the bottom bearing area and prevent landslides during mining.

[0073] By calculating the appropriate slope angle α of the working face step 6, it is possible to avoid the problem of the step structure being unstable and prone to landslides when the slope angle α of the working face step 6 is designed to be too large. It is also possible to avoid the problem of the normal mining operation of the bucket wheel being affected when the slope angle α of the working face step 6 is designed to be too small.

[0074] In one embodiment, determining the mining zone width A of the bucket wheel excavator in the mining sub-area 3 according to the layer height H and the slope angle α includes:

[0075] According to the excavation radius of the uppermost layer of step 6 of the excavation working surface and the excavation radius of the lowest layer of step 6 of the excavation working surface Get the maximum digging radius of a bucket wheel excavator

[0076] The width of the mining zone A is calculated according to the following formula:

[0077]

[0078] Among them, φ1 is the swing angle of the bucket wheel arm toward the inner side of the step when the uppermost layer of the working face step 6 is excavated, φ2 is the swing angle of the bucket wheel arm toward the side of the goaf when the lowermost layer of the working face step 6 is excavated, H is the layer height, α is the slope angle, ctgα is the cotangent value of α, that is,

[0079] By calculating the mining belt width A, the frequency of leveling the working surface and the number of times the belt conveyor is moved when the bucket wheel excavator mines a mining belt can be effectively reduced, thereby improving the mining time and mining efficiency of the bucket wheel excavator.

[0080] Maximum digging radius R max The calculation can be done using the following steps:

[0081] 1) Establish an equation based on the excavation radius of the top layer and the bottom layer, expressed as:

[0082]

[0083] Where L is the horizontal boom length from the bucket wheel center to the rotation center, θ1 is the pitch angle of the boom at the uppermost layer, θ2 is the pitch angle of the boom at the lowermost layer, and h is the height difference between the uppermost layer and the lowermost layer.

[0084] 2) Solve the boom length and pitch angle range by elimination method, expressed as:

[0085]

[0086] 3) Calculate the maximum excavation radius R max The corresponding boom is bent down to the limit angle θ minWhen the value is set, θ min Generally, it is -15°, which is expressed as R max =L·cosθ min .

[0087] S4. Excavation operation is performed on the working surface step 6 by using a bucket wheel excavator.

[0088] Specifically, the bucket wheel excavator begins excavating the uppermost layer of the current mining sub-area 3 according to the aforementioned settings, such as at least the layer height H, the slope angle α, and the mining zone width A. The bucket wheel excavator's tail discharge port is equipped with a vehicle for loading and unloading materials. After completing excavation of the lowermost layer of the current mining sub-area 3, the bucket wheel excavator is mobilized to repeat the operation for the next mining sub-area 3.

[0089] That is, the slicing form can be determined in step 2 for the current mining sub-area 3, and the slice height H, slope angle α, and mining zone width A can be calculated in step 3. Then, mining operations can be performed on this mining sub-area 3. Once the mining operation in the current mining sub-area 3 is completed, steps 2 and 3 are repeated for the next mining sub-area 3, and mining operations can be performed on the next mining sub-area 3. This continues until all mining sub-areas 3 are completed.

[0090] This invention proposes a bucket-wheel excavator mining method for high-altitude cold regions. This method divides and plans the mining area 1 by excavating trenches 2, dividing the overall project into multiple sub-projects, facilitating efficient scheduling and construction progress. Furthermore, the excavation slicing method is selected based on the structural properties of the rock and soil layers in different mining sub-areas 3, further improving construction efficiency. Designing an appropriate mining belt width for the working face step 6 in each mining sub-area 3 effectively reduces the frequency of working face leveling and belt conveyor relocation, thereby increasing the bucket-wheel excavator's operating time and improving mining efficiency.

[0091] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A bucket wheel excavator mining method in high-altitude cold areas, characterized in that ,include: Divide the mining area into multiple mining sub-areas; Determining the slicing mode and operation mode of the bucket wheel excavator according to the structural properties of the rock and soil layers in the mining sub-area; Determining the layer height and slope angle of the working face step of the mining sub-area, and determining the mining zone width of the bucket wheel excavator on the working face step according to the layer height and the slope angle; The bucket wheel excavator is used to excavate the working surface step.

2. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: The step of dividing the mine area into a plurality of mining sub-areas comprises: A predetermined number of trenches in the mining area is determined, and the predetermined number of trenches are excavated in the mining area. Mining sub-areas are formed between adjacent trenches, and a difference in area between different mining sub-areas is less than a threshold.

3. The method for mining in cold regions using a bucket wheel excavator according to claim 2, characterized in that: The depth of the trench is 1.5m-2m, and the depth of the trench is greater than the thickness of the frozen soil layer distributed on the top layer of the mining sub-area.

4. The bucket wheel excavator mining method in alpine regions according to claim 2, characterized in that: Excavating the predetermined number of trenches in the mining area includes: A trench is dug, and for each trench, the soil layer obtained by digging the trench is evenly covered on the top of the frozen soil layer to form a covering soil layer, and the thickness of the covering soil layer is 0.5m-1m.

5. The method for mining in cold regions using a bucket wheel excavator according to claim 1, characterized in that: The slicing forms include vertical slicing and horizontal slicing; The determining of the slicing form of the bucket wheel excavator according to the structural properties of the rock and soil layer in the mining sub-area includes: Sampling the rock and soil layer in the mining sub-area to obtain mechanical properties of the rock and soil layer, and determining the slicing form of the bucket wheel excavator based on the mechanical properties of the rock and soil layer, wherein the mechanical properties of the rock and soil layer include rock layer hardness and rock layer thickness.

6. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: The layer height is 13m-15m.

7. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: Determine the slope angle of the working face step including: Acquiring operating parameters of the bucket wheel excavator, wherein the operating parameters include a bucket wheel arm swing angle and a bucket wheel free cutting angle; Determine that the slope angle satisfies: And α≤δ; in, It is the excavation radius of the top layer of the working face step. is the excavation radius of the lowest layer of the working face step, φ1 is the swing angle of the bucket wheel arm toward the inside of the step when excavating the uppermost layer of the working face step, θ is the free cutting angle of the bucket wheel in the horizontal section, δ is the free cutting angle of the bucket wheel in the vertical section, H is the layer height, and α is the slope angle.

8. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: The determining of the mining zone width of the bucket wheel excavator in the mining sub-area according to the layer height and the slope angle includes: According to the excavation radius of the uppermost layer of the working surface step and the excavation radius of the lowest layer of the working face step Get the maximum digging radius of the bucket wheel excavator The width of the mining zone is calculated according to the following formula: Among them, φ1 is the swing angle of the bucket wheel arm toward the inner side of the step when excavating the uppermost layer of the working face step, φ2 is the swing angle of the bucket wheel arm toward the side of the goaf when excavating the lowermost layer of the working face step, H is the layer height, α is the slope angle, and A is the width of the mining belt.

9. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: The excavation operation on the working surface step by the bucket wheel excavator includes: Using the bucket wheel excavator, excavation is started on the uppermost layer of the current mining sub-area according to at least the layer height, the slope angle, and the width of the mining zone, and the tail discharge port of the bucket wheel excavator is equipped with a vehicle for loading and unloading materials; After completing the excavation operation of the lowest layer in the current mining sub-area, the bucket wheel excavator is mobilized to repeat the operation on the next mining sub-area.

10. The bucket wheel excavator mining method in alpine regions according to claim 1, characterized in that: The working surface step is operated in the form of end mining working surface operation.

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