A method of upward filling mining with reserved interval pillars

Abstract

The present invention discloses an upward approach filling mining method with reserved interval pillars. The stope is divided and the mining and cutting engineering is arranged in the manner of the upward approach filling mining method. Mining is carried out in layers from bottom to top in the middle section. The ore body in the layers is divided into approaches and mined from the center to the two wings. During approach mining, the first mining approach is constructed from the vein lane perpendicular to the direction of the ore body to the boundary of the hanging wall of the ore body. Then, interval-type spalling mining is carried out on the side of the approach to form blasting compensation space for subsequent approach mining. Pillars are left at intervals between the spalling mining areas from the boundary of the vein lane. The approach is then filled and roofed. During approach filling, a filling retaining wall is constructed at the outer boundary of the spalling mining area to reserve blasting compensation space for the next approach mining. The present invention has the advantages of safe operation, large stope production capacity, high efficiency, and low cost.

Description

Technical Field

[0001] The invention belongs to the technical field of mine mining, and in particular relates to an upward approach filling mining method with reserved interval ore pillars. Background Art

[0002] Backfill mining involves filling the goaf with filler material while ore is being dropped, transported, and processed. The purpose of backfilling is to support the rock on either side of the goaf and create a foundation for continued stratified mining above. It is suitable for deposits where the ore and surrounding rock are unstable and large exposed areas are not permitted; where the surface requires protection; where rare and precious metal or high-grade ores are present; where sulfide deposits are prone to spontaneous combustion; and where the mineral deposits have complex geological conditions.

[0003] Because backfill mining maximizes mineral resource recovery and protects the underground and surface environments, it has been widely used in nonferrous and precious metal mines, particularly in recent years, driven by advancements in backfill materials, processes, pipeline transportation equipment, and technology. With the continuous reduction of backfill costs and the continued rise in mineral product prices, backfill mining, due to its irreplaceable advantages, is increasingly being used in mines such as coal and iron ore, where backfilling is traditionally unsuitable.

[0004] Among the many backfill mining methods, upward layered backfill mining is currently the most widely used method in my country's metal and non-metal mines. This method involves mining and backfilling from the bottom up using a roadway approach. The backfilling approach is carried out under the naturally stable or supported roof of the ore. It is suitable for deposits where both the ore and rock are unstable, but the ore body can basically ensure the stability of the backfilling approach.

[0005] Compared with the upward horizontal layered filling mining method, the upward horizontal approach filling mining method has a smaller exposed roof area and is safer and more reliable. However, it also has problems such as low mining efficiency and filling efficiency, limited approach specifications, full-section blasting technology required for approach construction, a large number of drillings and a long time, high unit consumption of explosives, long filling solidification time, many filling times, and high production costs. Summary of the Invention

[0006] In response to the problems existing in the above-mentioned existing upward layered approach filling mining method, the present invention discloses an upward approach filling mining method with reserved interval pillars, which includes the following steps:

[0007] Step 1: Divide the stope and arrange the mining and cutting works according to the upward approach filling mining method. Mining is carried out in layers from bottom to top in the middle section. Within the layers, a stope connecting road is constructed from the outside of the vein in a segmented level road to the boundary of the ore body footwall. Then, from the stope connecting road, a roadway along the vein is constructed in the footwall of the ore body to the boundaries of both sides of the stope. The ore body within the layers is divided into approaches for mining.

[0008] Step 2: Mining is carried out from the center to the two wings within the stope layer. At the center of the stope layer, the first mining approach is constructed from the vein lane perpendicular to the strike direction of the ore body to the boundary of the hanging wall of the ore body. The approach roof and the two sides are supported by anchor rods + mesh. Then, interval spalling mining is carried out on both sides of the first mining approach to form blasting compensation space for subsequent approach mining. Pillars are left at intervals between the spalling mining areas from the boundaries of the vein lanes. The spalling mining areas are supported by short anchor cables + mesh. After the spalling mining is completed, backfill retaining walls are erected at the outer boundaries of the spalling areas and the approach, and then the approach is filled and topped.

[0009] Step 3: After the filling and maintenance of the first mining route is completed, the two adjacent routes are mined at the same time. First, the route is constructed from the vein lane perpendicular to the direction of the ore body to the boundary of the upper wall of the ore body, and then the interval-type spalling mining is carried out on the side of the route close to the original rock to form a blasting compensation space for the subsequent route mining. Pillars are left at intervals between the spalling mining areas from the boundary of the vein lane. After the spalling mining is completed, the pillars on the side of the filling body are successively recovered from the upper wall of the ore body to the lower wall. In order to ensure the stability of the intersection of the route and the vein lane, the pillars at the boundary of the vein lane are not recovered. Then, a filling retaining wall is erected at the outer boundary of the spalling area and the route entrance, and then the route is filled and topped.

[0010] Step 4: After the filling and curing of the access road mined in step 3 is completed, the two access roads on one side of the filled access road are mined again. The mining and filling methods are the same as those in step 3. This cycle is repeated until the entire layer mining is completed.

[0011] Step 5: After the entire layer mining is completed, the layer is switched and the previous layer is mined. The layer mining and filling method is the same as steps 2 to 4. This cycle is repeated until the entire stope is mined.

[0012] Furthermore, the access road is an upslope of 0.3% from the lower wall to the upper wall, the length of the access road is the thickness of the ore body, and the cross-sectional specifications of the access road are determined according to the engineering geological conditions of the ore body rock and the magnitude of the ground stress.

[0013] Furthermore, the width of the spall mining is 1 / 2 of the width of the approach, the height of the spall mining is the height of the approach, and the length of a single spall mining area is greater than or equal to 3 times the single-cycle footage of the approach; the width of the pillar is 1 / 2 of the width of the approach, the length is not greater than the single-cycle footage of the approach, and the height is equal to the height of the approach.

[0014] Furthermore, the filling retaining wall is composed of wooden columns, steel grids, geotextiles and diagonal braces. The wooden columns are erected at the designed positions of the filling retaining wall and tied to the anchor rods of the top and bottom plates. A layer of steel grid is laid and fixed between the wooden columns, and 1 to 2 layers of geotextiles are laid on the steel grids. The wooden columns, steel grids and geotextiles constitute the filling retaining wall body. The filling retaining wall body is supported and fixed by diagonal braces, and a drainage pipe is also provided at the lower part of the filling retaining wall.

[0015] Furthermore, when mining in layers, the first mining approach adopts the tunneling method for mining, and the face is the only free face and compensation space for blasting; when mining with other approaches, when the side of the filling body is a pillar, mining is carried out by tunneling, and the face is the only free face and compensation space for blasting. When the side of the filling body is the spall area of the previous approach mining, the spall area is used as the main free face and compensation space for lateral blasting and collapse of the mine. At this time, the filling retaining wall on the side of the filling body in the spall area is demolished and recovered before blasting.

[0016] Furthermore, when the access road is filled, a filling pipe and an exhaust pipe are respectively set up on the top plate of the access road, and the height of the exhaust pipe is higher than the filling pipe; the filling is carried out in batches, and the filling height of each time does not exceed 1 / 3 to 1 / 4 of the access road height, and the upper layer is filled after the lower layer filling body solidifies.

[0017] Furthermore, when the access road is filled, a cemented filling body is used for filling, and the 28-day uniaxial compressive strength of the cemented filling body is greater than or equal to 0.8~1.0MPa.

[0018] Preferably, the length of the anchor rod is 1.8~2.2m, the mesh size is 1.5m×1.5m~2m×2m, the length of the short anchor cable is 4~6mm, and the mesh size is 2m×2m~3m×3m.

[0019] Beneficial effects

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] (1) The mining efficiency of the stope is high and the production capacity is large. After the road construction is completed, the free surface and compensation space for the side road mining blasting are reserved near the side of the original rock ore body. This allows the mining of the adjacent road to be carried out by the side caving method, which effectively reduces the difficulty of the mining blasting, shortens the number of drilling holes and the drilling time, greatly improves the mining efficiency, and increases the mining production capacity.

[0022] (2) It can effectively reduce the cost of mining. On the one hand, by improving the efficiency and production capacity of mining, the cost per ton of ore can be effectively reduced. On the other hand, the approach mining is optimized from tunneling blasting to lateral blasting, which reduces the blasting difficulty and the unit consumption of pyrotechnics, and can also reduce mining costs.

[0023] (3) By pre-setting pillars, the stability of the filling wall is improved, the exposed area of the roof is reduced, and the stability of the approach roof is ensured while expanding the mining width. This increases the single filling area, reduces the number of fillings, and improves the filling efficiency. Since it is difficult to connect the roof during approach filling, several interval pillars are set on one side of the vein outside the tunnel to ensure the stability of the roof of the vein outside the tunnel.

[0024] (4) The present invention can improve filling efficiency. By reserving ore pillars and installing a number of filling plate walls and drainage pipes between the ore pillars, water can be filtered simultaneously on the plate walls on both sides of the access road, achieving rapid and uniform filtration of the filling slurry, accelerating the solidification time of the filling body, and improving the filling work efficiency.

[0025] The technical solution of the present invention is further described in detail below through the accompanying drawings and specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a schematic diagram of the first-stage mining route of the upper route filling mining method with reserved interval pillars in an embodiment.

[0027] Figure 2 It is a schematic diagram of the slab mining of the first-layer mining approach of the upward approach filling mining method with reserved interval pillars in an embodiment.

[0028] Figure 3 This is a schematic diagram of the installation of filling retaining walls and filling pipes for the first-layer mining approach of the upward approach filling mining method with reserved interval pillars in an embodiment.

[0029] Figure 4 for Figure 3 A is an enlarged schematic diagram.

[0030] Figure 5 This is a schematic diagram of a filling retaining wall structure of an upward approach filling mining method with reserved interval pillars in an embodiment.

[0031] Figure 6 This is a schematic diagram of the mining on both sides of the first mining route of the layered upper route filling mining method with reserved interval pillars in an embodiment.

[0032] Figure 7 It is a schematic diagram of the sidewall mining and pillar recovery on both sides of the first mining route of the layered upward route filling mining method with reserved interval pillars in an embodiment.

[0033] Numbers in the figure: 1—vein tunnel, 2—ore body, 3—first mining approach, 4—mine pillar, 5—slab mining area, 6—cemented backfill, 7—wooden pillar, 8—diagonal brace, 9—steel grid, 10—geotextile, 11—drainage pipe, 12—backfill pipe, 13—exhaust pipe, 14—approach. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions of various embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-Figure 7 The method of upward filling mining with reserved interval pillars shown in the figure is a preferred solution of the present invention. The technical solution provided by the present invention includes the following steps:

[0036] Step 1. Divide the stope and arrange the mining and cutting engineering according to the upward approach filling mining method. Carry out mining in layers from bottom to top in the middle section. Construct the stope connecting road from the vein outside the layer to the boundary of the lower wall of the ore body 2. Then, construct the vein tunnel 1 along the stope from the stope connecting road in the lower wall of the ore body 2 to the boundaries of both sides of the stope. The ore body 2 in the layer is divided into approaches for mining; the approach is 0.3% upslope from the lower wall to the upper wall, the approach length is the thickness of the ore body 2, and the approach section specifications are determined according to the engineering geological conditions and ground stress of the rock of the ore body 2.

[0037] Step 2: Mining is carried out from the center to the two wings within the mining area. At the center of the mining area, the first mining approach 3 is constructed from the vein tunnel 1 perpendicular to the direction of the ore body 2 to the upper wall boundary of the ore body 2. The first mining approach 3 is mined by excavation, and blasting is carried out with the face as the only free face and compensation space; the approach roof and two sides are supported by anchor rods + mesh, and then interval spalling mining is carried out on both sides of the first mining approach 3 to form a blasting compensation space for subsequent approach mining. Pillars 4 are left at intervals between the spalling mining areas from the boundary of the vein tunnel 1. The spalling mining area 5 is supported by short anchor cables + mesh. After the spalling mining is completed, filling retaining walls are erected at the outer boundary of the spalling area and the approach, and then the approach is filled and topped.

[0038] Step 3: After the filling and maintenance of the first mining route 3 are completed, the two adjacent routes 14 are mined at the same time. First, the route is constructed from the vein tunnel 1 perpendicular to the direction of the ore body 2 to the upper wall boundary of the ore body 2. When the route 14 is mined, if there is a ore pillar 4 on the side of the filling body, mining is carried out by excavation. The face is the only free surface and compensation space for blasting. If there is a spalling area on the side of the filling body that is mined by the previous route, the spalling area is used as the main free surface and compensation space for lateral blasting and collapse. At this time, the filling retaining wall on the side of the spalling area on the side of the filling body is demolished and recovered before blasting. Then, interval spalling is carried out on the side of the approach close to the original rock to form blasting compensation space for subsequent approach mining. Pillars 4 are left at intervals between the spalling mining areas 5 from the boundary of the vein tunnel 1. After the spalling is completed, the pillars 4 on the side of the filling body are successively recovered from the upper wall to the lower wall of the ore body 2. In order to ensure the stability of the intersection of the approach and the vein tunnel 1, the pillars 4 at the boundary of the vein tunnel 1 are not recovered. Then, filling retaining walls are erected at the outer boundary of the spalling area and the approach, and then the approach is filled and topped.

[0039] Step 4: After the filling and curing of the access road mined in step 3 is completed, the two access roads on one side of the two filling access roads are mined again. The mining and filling methods are the same as those in step 3. This cycle is repeated until the entire layer mining is completed.

[0040] Step 5: After the entire layer mining is completed, the layer is switched and the previous layer is mined. The layer mining and filling method is the same as steps 2 to 4. This cycle is repeated until the entire stope is mined.

[0041] The width of the spall mining is 1 / 2 of the width of the approach, the height of the spall mining is the height of the approach, and the length of a single spall mining area 5 is greater than or equal to 3 times the single-cycle footage of the approach; the width of the pillar 4 is 1 / 2 of the width of the approach, the length is not greater than the single-cycle footage of the approach, and the height is equal to the height of the approach.

[0042] The filling retaining wall is composed of wooden columns 7, steel grids 9, geotextiles 10 and diagonal braces 8. The wooden columns 7 are erected at the designed position of the filling retaining wall and tied to the anchor rods of the top and bottom plates. A layer of steel grids 9 is laid and fixed between the wooden columns 7, and 1 to 2 layers of geotextiles 10 are laid on the steel grids. The wooden columns 7, steel grids 9 and geotextiles 10 constitute the filling retaining wall body. The filling retaining wall body is supported and fixed by diagonal braces 8. A drainage pipe 11 is also provided at the lower part of the filling retaining wall.

[0043] When the access road is filled, a filling pipe 12 and an exhaust pipe 13 are respectively set up on the top plate of the access road, and the height of the exhaust pipe 13 is higher than the filling pipe 12; the filling is carried out in batches, and the filling height of each time does not exceed 1 / 3 to 1 / 4 of the access road height. The upper layer filling is carried out after the lower layer filling body solidifies.

[0044] When the access road is filled, a cementing filling body 6 is used for filling, and the 28-day uniaxial compressive strength of the cementing filling body 6 is greater than or equal to 0.8-1.0 MPa.

[0045] The length of the anchor rod is 1.8~2.2m, the mesh size is 1.5m×1.5m~2m×2m, the length of the short anchor cable is 4~6mm, and the mesh size is 2m×2m~3m×3m.

[0046] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method of upward filling mining with reserved interval pillars, characterized in that: The following steps are involved: Step 1: Divide the stope and arrange the mining and cutting works according to the upward approach filling mining method. Mining is carried out in layers from bottom to top in the middle section. Within the layers, a stope connecting road is constructed from the outside of the vein in a segmented level road to the boundary of the ore body footwall. Then, from the stope connecting road, a roadway along the vein is constructed in the footwall of the ore body to the boundaries of both sides of the stope. The ore body within the layers is divided into approaches for mining. Step 2: Mining is carried out from the center to the two wings within the stope layer. At the center of the stope layer, the first mining approach is constructed from the vein lane perpendicular to the strike direction of the ore body to the boundary of the hanging wall of the ore body. The approach roof and the two sides are supported by anchor rods + mesh. Then, interval spalling mining is carried out on both sides of the first mining approach to form blasting compensation space for subsequent approach mining. Pillars are left at intervals between the spalling mining areas from the boundaries of the vein lanes. The spalling mining areas are supported by short anchor cables + mesh. After the spalling mining is completed, backfill retaining walls are erected at the outer boundaries of the spalling areas and the approach, and then the approach is filled and topped. Step 3: After the filling and maintenance of the first mining route is completed, the two adjacent routes are mined at the same time. First, the route is constructed from the vein lane perpendicular to the direction of the ore body to the boundary of the upper wall of the ore body, and then the interval-type spalling mining is carried out on the side of the route close to the original rock to form a blasting compensation space for the subsequent route mining. Pillars are left at intervals between the spalling mining areas from the boundary of the vein lane. After the spalling mining is completed, the pillars on the side of the filling body are successively recovered from the upper wall of the ore body to the lower wall. In order to ensure the stability of the intersection of the route and the vein lane, the pillars at the boundary of the vein lane are not recovered. Then, a filling retaining wall is erected at the outer boundary of the spalling area and the route entrance, and then the route is filled and topped. Step 4: After the filling and curing of the access road mined in step 3 is completed, the two access roads on one side of the filled access road are mined again. The mining and filling methods are the same as those in step 3. This cycle is repeated until the entire layer mining is completed. Step 5: After the entire layer mining is completed, the layer is switched and the previous layer is mined. The layer mining and filling method is the same as steps 2 to 4. This cycle is repeated until the entire stope is mined.

2. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: The access road slopes up 0.3% from the lower wall to the upper wall, the length of the access road is the thickness of the ore body, and the cross-sectional specifications of the access road are determined according to the engineering geological conditions of the ore body rock and the magnitude of the ground stress.

3. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: The width of the spall mining is 1 / 2 of the width of the approach, the height of the spall mining is the height of the approach, and the length of a single spall mining area is greater than or equal to 3 times the single-cycle footage of the approach; the width of the pillar is 1 / 2 of the width of the approach, the length is not greater than the single-cycle footage of the approach, and the height is equal to the height of the approach.

4. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: The filling retaining wall is composed of wooden columns, steel grids, geotextiles and diagonal braces. The wooden columns are erected at the designed positions of the filling retaining wall and tied to the anchor rods of the top and bottom plates. A layer of steel grid is laid and fixed between the wooden columns, and 1 to 2 layers of geotextiles are laid on the steel grids. The wooden columns, steel grids and geotextiles constitute the filling retaining wall body. The filling retaining wall body is supported and fixed by diagonal braces. A drainage pipe is also provided at the lower part of the filling retaining wall.

5. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: During stratified mining, the first mining approach adopts the tunneling method for mining, and the face is the only free face and compensation space for blasting; when the other approaches are mining, when the side of the filling body is the pillar, the tunneling method is adopted for mining, and the face is the only free face and compensation space for blasting. When the side of the filling body is the spall area of the previous approach mining, the spall area is used as the main free face and compensation space for lateral blasting and collapse of the mine. At this time, the filling retaining wall on the side of the filling body in the spall area is demolished and recovered before blasting.

6. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: When the access road is filled, a filling pipe and an exhaust pipe are respectively set up on the access road top plate, and the height of the exhaust pipe is higher than the filling pipe; the filling is carried out in batches, and the filling height of each time does not exceed 1 / 3 to 1 / 4 of the access road height. The upper layer is filled after the lower layer filling body solidifies.

7. The method of mining with upward filling of reserved interval pillars according to claim 6 is characterized in that: When the access road is filled, a cemented filling body is used for filling, and the 28-day uniaxial compressive strength of the cemented filling body is greater than or equal to 0.8 to 1.0 MPa.

8. The method of mining with upward filling of reserved interval pillars according to claim 1 is characterized in that: The length of the anchor rod is 1.8 to 2.2 m, and the mesh size is 1.5 m×1.5 m to 2 m×2 m. The length of the short anchor cable is 4 to 6 mm, and the mesh size is 2 m×2 m to 3 m×3 m.

Images