A mining method and slicing mining method for gently inclined medium-thick ore body

Abstract

This invention relates to a mining method and a layered mining method for a gently dipping, medium-thick ore body with the same-layer approach. The method involves constructing a cutting vein, with the end of the cutting vein on the footwall side of the ore body being higher than the end on the hanging wall side. Multiple approaches are sequentially constructed along the cutting vein from the hanging wall to the footwall, involving mining and backfilling. In adjacent approaches, the approach behind is higher than the approach in front, allowing the backfill slurry to flow into the empty roof area of ​​the approach ahead after backfilling, thus achieving roof connection. The method of this invention results in high ore body mining efficiency.

Description

Technical Field

[0001] This invention relates to the field of ore body mining technology, specifically to a mining method and a layered mining method for gently dipping, medium-thick ore bodies using the same-layer approach. Background Technology

[0002] The statements herein provide only background information in relation to this invention and do not necessarily constitute prior art.

[0003] Gently dipping, medium-thick ore bodies refer to ore bodies with a dip angle of 5-30° and a thickness of 4-15m. Safe and efficient mining of gently dipping, medium-thick ore bodies under fractured ore-rock conditions in metal mines has always been a mining challenge both domestically and internationally. This is due to several factors: the gentle dip angle makes ore flow difficult, the high unsupported roof height results in a large exposed area, leading to extensive roof support work, significant losses and dilution during mining, and low efficiency. Because the gentle dip angle prevents gravity-based ore transport, methods like shallow-hole casting are unsuitable, further reducing transport efficiency. The thickness of the ore body limits the choice of preparatory works. Preparatory works outside the vein increase the workload and thus the mining cost, while in-vein preparatory works limit the increase in stope production capacity. Under fractured ore body conditions, the exposed roof area should not be too large, increasing support difficulty and limiting the choice of mining methods.

[0004] With the increasing level of mechanization and the requirements for managing goaf areas in mining areas, the upward horizontal stratified strike approach backfilling mining method is being used more frequently. For example... Figure 1-2 As shown, this method involves constructing an external tunnel 1, followed by the construction of a layered connecting tunnel 2 from the external tunnel 1 to the designated layer position. Then, a cutting vein 3 is constructed, extending horizontally to the hanging wall 5 of the ore body. From the hanging wall 5 to the footwall 6, access roads 4 are arranged. Ore body mining is carried out during access road construction, and this process is repeated sequentially for each access road. All access roads have the same specifications, and the roof and floor are at the same level. After each access road is mined, backfilling is performed. The next access road is mined on one side of the backfill, until the footwall access road is mined and backfilling is completed. However, this mining method requires that each access road be backfilled to the roof to ensure that the exposed roof area is minimized when the next access road is mined, thus ensuring access road mining safety. However, in actual mining operations, if… Figure 3 As shown, the tailings are transported by gravity flow and require filtration during the intake process. This results in a certain space remaining below the intake roof after the backfill solidifies (the backfill does not reach the roof), meaning the backfill surface cannot reach the top of the intake. Figure 4As shown, multiple inlet fillings not reaching the roof can lead to large areas of unsupported roof, posing a significant safety hazard of roof collapse during inlet mining. One solution to this problem is to perform multiple small-volume fillings, cycling through filling, filtration, and solidification to ensure the filling material in the inlet is approximately connected to the roof. However, this method is time-consuming, delays the project, and significantly impacts ore production. Furthermore, the closer to roof contact, the more frequently the filling pipeline valves open and close, making it very difficult to implement in practice and thus less feasible.

[0005] Furthermore, when a void appears in the lower access road, the upper access road construction requires backfilling the void area with ore to ensure the uplift height, or reducing the uplift height to the filling surface, which reduces the actual ore output during mining, affects ore production, and reduces economic benefits. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a mining method for a gently dipping, medium-thick ore body with the same-layer approach, which can improve mining efficiency, reduce backfilling and support costs, and ensure safety.

[0007] To achieve the above objectives, the present invention adopts the following technical solution.

[0008] In a first aspect, embodiments of the present invention provide a mining method for a gently dipping, medium-thick ore body with the same-layer approach. The method involves constructing a cutting vein, with the end of the cutting vein on the footwall side of the ore body being higher than the end on the hanging wall side. Multiple approaches are sequentially constructed for mining and backfilling along the cutting vein from the hanging wall to the footwall. In adjacent approaches, the approach behind is higher than the approach in front, so that the backfill slurry can flow into the empty roof area of ​​the approach in front after the approach behind is backfilled, thus achieving backfilling and roof connection.

[0009] Optionally, during the mining process, a three-center arch cross-section is used for the construction of the access road. Before backfilling is carried out after the access road mining is completed, the access road cross-section is expanded to a rectangular cross-section.

[0010] Optionally, the approach of the three-center arch section can be expanded to a rectangular section by blasting.

[0011] Optionally, the angle between the cutting vein and the horizontal plane is 6.5°-7.5°.

[0012] Optionally, the last access route at the footwall of the ore body may be filled multiple times to ensure that the height of the empty roof area of ​​the last access route is no more than 20cm.

[0013] Optionally, the cutting vein can be constructed along the direction from the footwall to the hanging wall of the ore body.

[0014] Secondly, embodiments of the present invention provide a layered mining method for gently dipping, medium-thick ore bodies, comprising the following steps:

[0015] Step 1: Layer the gently dipping, medium-thick ore body vertically;

[0016] Step 2: Construct an external tunnel on one side of the footwall of the ore body, with the external tunnel set along the strike of the ore body;

[0017] Step 3: Construct layered connecting roadways at the designated location in the outer vein roadway to the designated layer of ore body in the footwall of the ore body;

[0018] Step 4: Mining the ore body of the designated layer using the same-layer mining method for gently dipping medium-thick ore bodies described in the first aspect;

[0019] Step 5: Repeat steps 3-4 until the ore body is fully mined.

[0020] Optionally, layered connecting tunnels can be constructed in the middle of the outer tunnel.

[0021] Optionally, the gently dipping, medium-thick ore body can be segmented vertically, with adjacent segments connected by panel ramps, and each segment can be mined according to the methods in steps 1-5.

[0022] Optionally, an external tunnel is provided on one side of the footwall of each gently dipping, medium-thick ore body.

[0023] The beneficial effects of this invention are:

[0024] 1. In the mining method of the present invention, since the height of the rear access road is higher than that of the front access road, the filling slurry can flow into the empty roof area of ​​the front access road during the back access road filling process, so that the front access road can achieve complete roof filling and connection, which can save the time of repeated filling and roof connection, improve the access road mining efficiency. Since the access road is completely connected to the roof, the exposed area of ​​the access road roof is greatly reduced, avoiding the phenomenon of large-area empty roof causing the access road roof to be unsupported by filling body and thus causing damage and instability, ensuring the safety of the access road roof and reducing the safety hazard of roof and surrounding rock collapse.

[0025] 2. The mining method of the present invention, since the access route can achieve complete roof contact, does not need to consider the empty roof area of ​​the lower access route when raising the layer height of the upper access route between two adjacent access routes. It does not need to use ore to backfill the empty roof area of ​​the lower access route or reduce the layer height. It can raise the layer according to the set height, ensuring the mining volume of each operation cycle and layer, and improving mining efficiency.

[0026] 3. In the mining method of the present invention, the cross section of the access road is expanded into a rectangle before the access road is filled, so that the filling slurry will not be blocked by the ore on both shoulders of the three-center arch cross section when the access road is filled, thus ensuring that the filling slurry of the access road can smoothly enter the access road. Attached Figure Description

[0027] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments of this application and their descriptions are used to explain this application and do not constitute a limitation thereof.

[0028] Figure 1 Plan view of existing mining methods for gently dipping, medium-thick ore bodies;

[0029] Figure 2 Elevation view of existing mining methods for gently dipping, medium-thick ore bodies;

[0030] Figure 3 A schematic diagram illustrating the presence of a void in a single approach for mining existing gently dipping, medium-thick ore bodies.

[0031] Figure 4 A schematic diagram illustrating the large-area open roof phenomenon encountered in existing mining methods for gently dipping, medium-thick ore bodies.

[0032] Figure 5 This is a plan view of the mining method in Embodiment 1 of the present invention;

[0033] Figure 6 This is an elevation view of the mining method in Embodiment 1 of the present invention;

[0034] Figure 7 This is a schematic diagram of the route expansion brush in Embodiment 1 of the present invention;

[0035] Figure 8 A schematic diagram showing the obstruction of ore flow to fill slurry at the shoulder of the three-core arch cross-section.

[0036] Figure 9 This is a schematic diagram of the filling of the empty roof area of ​​the forward approach in Embodiment 1 of the present invention;

[0037] Figure 10 This is a schematic diagram of the raised-layer construction in Embodiment 2 of the present invention;

[0038] Among them, 1. External tunnel, 2. Layered connecting tunnel, 3. Cutting through the vein, 4. Access road, 5. Hanging wall of the ore body, and 6. Footing wall of the ore body. Detailed Implementation

[0039] Example 1

[0040] This embodiment provides a method for mining with the same access route in gently dipping, medium-thick ore bodies. It improves upon the existing method of horizontal access route filling mining in gently dipping, medium-thick ore bodies to overcome the defect of poor access roof effect. In the traditional method of mining with the same access route filling, the cutting vein is set horizontally, and then multiple access routes are constructed and the ore body is mined from the hanging wall to the footwall of the ore body on both sides of the cutting vein. After the construction of the previous access route and the ore body mining are completed, filling is carried out. After the filling is completed, the construction of the next access route and the ore body mining are carried out until the access route mining at the footwall of the ore body is completed.

[0041] This embodiment improves upon the above method, such as... Figures 5-6 As shown, it includes the following steps:

[0042] Step 1: Construction of the cutting vein 3. The construction method of the cutting vein 3 can adopt the existing mining preparation and cutting engineering construction method, which will not be described in detail here. In this embodiment, the cutting vein 3 is no longer set horizontally, but inclined, and the height of the lower end of the ore body 6 of the cutting vein 3 is higher than the height of the upper end of the ore body 5, so that the cutting vein forms a set angle with the horizontal plane.

[0043] The angle between the cutting vein 3 and the horizontal plane is 6.5°-7.5°. In this embodiment, the angle between the cutting vein 3 and the horizontal plane is 7°. The angle between the cutting vein 3 and the horizontal plane is determined based on the width of the access path 4 and the height difference between two adjacent access paths 4.

[0044] The existing construction methods can be used for cutting through vein 3, and construction can be carried out from the footwall 6 of the ore body to the hanging wall 5.

[0045] Step 2: After the cutting vein 3 is completed, the access route 4 will be constructed. First, the first access route will be constructed. The first access route is located at the hanging wall 5 of the ore body and is located on both sides of the cutting vein 3.

[0046] During the construction of the first access route, in order to ensure the stability of the access route roof, the access route section adopted a three-center arch section with a width of 4 meters and a height of 4 meters. The first access route was set up along the ore body direction on both sides of the cutting vein 3.

[0047] The construction of the first approach and the mining method of the ore body can be carried out using the existing approach construction methods, and will not be described in detail here.

[0048] After the first access road was completed, backfilling began. Backfilling was carried out using backfill slurry. The backfill material consisted of graded tailings as aggregate, mixed with a certain proportion of binder, and then thoroughly mixed with water at the backfilling station to form a fluid backfill slurry. This slurry was then transported to the mining access road through pipelines. The concentration of the backfill slurry was 60%-70%.

[0049] Before filling, the approach section, which has a three-centered arch cross-section at the end, is first widened and reshaped into a rectangular cross-section, specifically, as follows: Figure 7 As shown, blast holes are drilled at the two shoulders of the three-center arch section of the first approach, and then explosives are used to blast the ore at the two shoulders, forming a rectangular cross section.

[0050] Since blasting construction will damage the original roof slab and the access road will be unsupported, the blasting construction time should be minimized as much as possible according to the actual situation, and the filling operation should be carried out after the blasting construction is completed.

[0051] Then, a filling retaining wall is constructed at the intersection of the first approach and the cutting vein 3 to prevent the filling grout from flowing into the cutting vein. After the filling retaining wall is constructed, the filling construction of the first approach begins.

[0052] The filling grout is filled to the top surface of the first inlet, that is, the first inlet is filled with filling grout.

[0053] Step 3: After the first access route is filled, construction of the second access route begins. Along the direction from the hanging wall to the footwall of the ore body, the second access route is set behind and close to the first access route.

[0054] The first and second access paths are arranged along the direction of the cutting vein 3. Therefore, the height of the second access path is higher than that of the first access path. In this embodiment, based on the angle of the cutting vein 3 and the size of the access path 4, the height of the second access path is 0.5 meters higher than that of the first access path. That is, the top surface of the second access path is 0.5 meters higher than the top surface of the first access path, and the bottom surface of the second access path is 0.5 meters higher than the bottom surface of the first access path.

[0055] The construction method for the second route is the same as that for the first route; both can be constructed using existing methods.

[0056] After the second route was completed, the cross-section of the second route was expanded to a rectangular cross-section. The expansion method was the same as that of the first route, and will not be repeated here.

[0057] After the second access route was expanded, filling began. First, a retaining wall was constructed, and then the second access route was filled with filling grout. During the filling process, the second access route was completely filled with filling grout, as shown below. Figure 8 As shown, in a traditional three-center arch section approach, even with a height difference, the ore at the shoulder of the section will obstruct the flow of filling grout from the rear approach to the front approach. Since both the first and second approaches are rectangular sections, there is no ore obstruction between them, and the height difference between the first and second approaches further hinders this process. Figure 9 As shown, after the second inlet is filled, the filling slurry can flow by gravity into the empty roof area at the top of the first inlet, filling the empty roof area, thereby enabling the first inlet to be fully connected to the roof.

[0058] After the second inlet is filled, the slurry level drops due to water filtration. However, even though the slurry level drops, the height difference with the first inlet still allows the empty area of ​​the first inlet to be filled, achieving complete connection of the first inlet to the top.

[0059] Step 4: The construction and backfilling of multiple access routes are carried out sequentially using the method described in Step 3 until the access route corresponding to the footwall of the ore body is completed. In this embodiment, when backfilling the last access route, multiple backfilling operations are required to ensure that the height of the unsupported area does not exceed 20cm.

[0060] Using the method of this embodiment, after the rear approach is filled, the filling slurry can flow into the empty roof area of ​​the front approach due to the height difference between the front and rear approaches, so that the front approach can be completely filled and connected to the roof. This can save the time of repeated filling and roof connection, improve the efficiency of approach mining. Since the approach is completely connected to the roof, the exposed area of ​​the approach roof is greatly reduced, avoiding the phenomenon of damage and instability caused by a large area of ​​empty roof without the support of filling body, ensuring the safety of the approach roof, reducing the safety hazard of roof and surrounding rock collapse. At the same time, since the approach is completely connected to the roof, the process of backfilling the empty roof area with ore is eliminated, so that construction can be carried out according to the set lifting height, ensuring the mining volume of each operation cycle and layer, and improving mining efficiency.

[0061] Example 2:

[0062] This embodiment provides a layered mining method for gently dipping, medium-thick ore bodies, such as... Figures 5-6 As shown, it includes the following steps:

[0063] The gently dipping, medium-thick ore body is vertically segmented, and each segment is further divided into layers. Adjacent segments are connected by panel ramps, and existing methods can be used to construct the panel ramps. In this embodiment, the ore body is vertically divided into two segments, each segment being further divided into four layers: a lower second layer, a lower first layer, a horizontal layer, and an upper second layer, from bottom to top.

[0064] Each section of the ore body is mined in layers, and the mining methods for two sections are the same. The method for mining one section in layers will be used as an example for explanation:

[0065] Includes the following steps:

[0066] Step a: Construct an external channel 1 on one side of the footwall of the ore body. The external channel 1 is set along the strike of the ore body. In this embodiment, a corresponding external channel 1 is set for each segment of the ore body, and the height of the external channel 1 corresponds to the height of the leveling layer. The panel ramps of adjacent ore body segments are also constructed at the footwall of the ore body. Both the external channel 1 and the panel ramps can be constructed using existing quasi-cutting engineering methods.

[0067] The reason for constructing the inclined ramp and external tunnel 1 in the lower plate 6 of the ore body is that the joints and fissures in the lower plate 6 of the ore body are not obvious and the surrounding rock is stable. The upper plate of the ore body is filled with 10cm thick backfill mud. It is extremely unsafe to arrange the mining and cutting project in the upper plate 5 of the ore body.

[0068] Step b: Begin construction of layered connecting roadway 2 at the middle position of the outer channel 1, until the layered connecting roadway 2 is constructed to the position corresponding to the lower second layer.

[0069] Step c: The method of Example 1 is used to mine the downward two-layered ore body, including the construction of cutting the cross vein 3, the construction of the access road 4 in sequence, and backfilling. The specific method is described in detail in the example and will be repeated here.

[0070] Step d: As Figure 10 As shown, after the construction of the downward two-layer ore body is completed, the lifting layer construction is carried out. The lifting layer height is 4 meters. Specifically, the layer connecting roadway 2 is constructed again in the middle of the outer roadway 1. The layer connecting roadway 2 is constructed to the corresponding position of the downward first layer. Then, the ore body of the downward first layer is mined using the method of Example 1.

[0071] Step e: Repeat step d until all layers of ore body have been mined.

[0072] Both sections of the ore body were mined using the same method. The mining method in this embodiment shortened the construction period, ensured construction safety, and improved mining efficiency.

[0073] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A method of mining gently inclined medium thick ore bodies with a horizontal slice, characterized in that, The construction cutting through the vein is located at the end of the lower side of the ore body higher than the end of the upper side of the ore body, and the mining and filling construction of multiple entries are carried out along the cutting through the vein from the upper side of the ore body to the lower side of the ore body, and in adjacent entries, the entry in the rear is higher than the entry in the front so that the filling slurry can flow into the empty roof area of the front entry after the filling of the rear entry to realize the filling of the roof. During mining, the three-center arch section is used to construct the entry, and before filling, the entry section is expanded to a rectangular section. The angle between the cutting through the vein and the horizontal plane is 6.5°-7.5°.

2. A method of mining gently inclined medium thick ore bodies by the same level drifts, according to claim 1, characterized in that, The three-center arch section is expanded to a rectangular section by blasting.

3. A method of mining gently inclined medium thick ore bodies by the same level drifts, according to claim 1, characterized in that, The last entry at the lower side of the ore body is filled multiple times to ensure that the height of the empty roof area of the last entry is not greater than 20 cm.

4. A method of mining gently inclined medium thick ore bodies by the same level drifts, according to claim 1, characterized in that, The cutting through the vein is constructed from the lower side of the ore body to the upper side of the ore body.

5. A sublevel mining method for gently inclined medium thick ore bodies, characterized in that, The method comprises the following steps: Step 1: stratifying the gently inclined medium-thick ore body in the vertical direction; Step 2: constructing an out-of-vein roadway on the lower side of the ore body, and the out-of-vein roadway is arranged along the strike of the ore body; Step 3: constructing a stratified connecting roadway to the position of the set layer of the ore body on the lower side of the ore body at the set position of the out-of-vein roadway; Step 4: mining the ore body of the set layer by using the mining method of the gently inclined medium-thick ore body of the same layer according to any one of claims 1-4; Step 5: repeating steps 3-4 until the mining of the ore body is completed.

6. A bench and fill method of mining gently inclined medium thick ore bodies as claimed in claim 5, wherein, The stratified connecting roadway is constructed at the middle position of the out-of-vein roadway.

7. A bench and fill method of mining gently inclined medium thick ore bodies as claimed in claim 5, wherein, The gently inclined medium-thick ore body is segmented in the vertical direction, and adjacent two segments are connected by a panel slope, and each segment is mined according to steps 1-5.

8. A bench and fill method of mining gently inclined medium thick ore bodies as claimed in claim 5 wherein, An out-of-vein roadway is arranged on the lower side of the ore body of each segment of the gently inclined medium-thick ore body.

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