A room-and-pillar mining method with subsequent filling for gently inclined to inclined ore bodies

Abstract

The invention discloses a post-stowing room-and-pillar mining method for gently inclined to inclined ore bodies, which relates to the technical field of mining and solves the existing technical problems. It includes Step 1: determining the working face layout method; Step 2: arranging the development and cutting headings; Step 3: stoping; Step 4: stowing. The process of the invention is simple, has a high degree of mechanization, large production capacity, high efficiency, and less development and cutting work volume. Moreover, it is a mining method for medium-thick ore bodies in gently inclined to inclined ore bodies that will not cause collapse of the overlying strata or the ground surface after mining. While achieving efficient mining, it can make full use of tailings sand and will not affect the upper ecological environment. The stoping of ore rooms and ore pillars is carried out by using large-scale mechanical equipment, which has the advantages of low labor intensity of workers, good safety, large production capacity, and high efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of mining, and more specifically to the technical field of the room-and-pillar mining subsequent filling mining method for gently inclined to inclined ore bodies. Background Art

[0002] A gently inclined to inclined medium-thick ore body refers to an ore body with an ore body dip angle between 15° and 50° and a thickness of 4 to 10 m. For this part of the ore body, due to the dip angle being greater than 15°, it is difficult for equipment to pass and for workers to stand and operate during the operation, and the mined ore cannot all be discharged by its own weight. The stoping of such ore bodies has always been a difficult problem in the mining industry.

[0003] Due to the inherent mining technical conditions of gently inclined to inclined medium-thick ore bodies, such as: the dip angle is small, and the caved ore cannot be completely discharged by its own weight; ore handling equipment must be used for ore drawing in the stope. Because the ore body thickness is relatively large, personnel and equipment operate in the exposed open stope, and safety is difficult to guarantee. From the mining situation of gently inclined to inclined medium-thick ore bodies at home and abroad, the open stoping method is generally adopted. In China, the open stoping method is currently generally used for mining. This type of method usually requires the setting of top pillars, bottom pillars and rib pillars. Workers need to enter the open stope for operation, and there are generally problems such as low recovery rate, high dilution rate, low mechanization level, low efficiency, high labor intensity of workers, and poor safety. Moreover, after the stoping of the ore body, the overlying surrounding rock will collapse, forming a large-scale caving circle on the surface, causing great damage to the surrounding safety and ecological environment.

[0004] How to solve the above technical problems has become the direction of efforts of those skilled in the art. Summary of the Invention

[0005] The purpose of the present invention is to provide a room-and-pillar mining subsequent filling mining method for gently inclined to inclined ore bodies in order to solve the technical problems existing in the mining of gently inclined to inclined medium-thick ore bodies. The process is simple, the mechanization level is high, the production capacity is large, the efficiency is high, the development and cutting work amount is less, and it will not cause collapse to the overlying rock stratum or the ground surface after mining. While efficiently mining, the tailings sand can be fully utilized without affecting the upper ecological environment.

[0006] The present invention specifically adopts the following technical solutions to achieve the above purpose:

[0007] A room-and-pillar mining subsequent filling mining method for gently inclined to inclined ore bodies, comprising the following steps:

[0008] Step 1, determination of the working face layout method

[0009] Above and below the coal face, the return airway and the haulage airway are respectively arranged along the strike, forming the ventilation, haulage and pedestrian passageways between the coal face and the upper and lower roadways; the coal face advances along the strike. When the dip angle of the coal seam is less than 15°, the working face is arranged along the true dip direction; when the dip angle of the coal seam is 15° - 50°, the working face is arranged in a pseudo-inclined direction, and the pseudo-inclination angle is determined according to the climbing ability of the rock drilling and ore drawing equipment, generally 5° - 25°.

[0010] Step 2: Layout of development and cut-off roadways

[0011] The gently inclined to inclined medium-thick ore bodies are divided into several panels along the strike. Each panel is divided into multiple stoping slices from top to bottom. In each stoping slice, there are stoping roadways along the strike of the ore body. First, enter the bottom of the panel through the ramp outside the panel and the trackless equipment access roadway, and develop the ramp within the panel for connecting each stoping roadway along the trackless equipment access roadway; the ramp within the panel is generally arranged along the footwall of the ore vein; considering the climbing ability of equipment such as rock drilling jumbo and load-haul-dump (LHD) vehicle, the ramp within the panel shall not exceed 15°. The ramp within the panel is arranged in a reverse layout within the panel, and a panel ore pass is arranged at the isolated ore pillar near the turning point. The bottom of the panel ore pass is connected to the cross-cut haulage roadway or the cross-cut roadway outside the ore vein in the middle section.

[0012] Step 3: Stoping

[0013] The stoping sequence is along the strike direction of the ore body. In the panel, the top-down progressive slicing stoping method is adopted. In each stoping slice, the ore rooms and ore pillars are arranged continuously at intervals, and stoping is carried out by the method of mining every other one. After the stoping of the ore room is completed, backfilling is carried out immediately. After the ore rooms on both sides of the ore pillar are backfilled and cured, the ore pillar is mined.

[0014] Each stoping slice includes the upper part, the lower part and the middle stoping roadway. In the first slice, the lower part is mainly mined, and the middle-section ore pillar is left unmined in the upper part; in each of the remaining stoping slices, the upper part of the current stoping slice is mined first in the stoping roadway of the upper stoping slice, and the lower part of the upper stoping slice is mined in the stoping roadway of the lower stoping slice.

[0015] Step 4: Backfilling

[0016] After the stoping is completed, the backfilling preparation work is carried out immediately. A filling drainage partition wall is set at the intersection of the stoping roadways in the mined ore room slices, and a corrugated filter water pipe is laid along the bottom to the filling drainage partition wall and passes through the filling drainage partition wall to drain the seepage water of the filling body in the stope; the curing time of the filling body is 3 to 4 months.

[0017] Further, in Step 2, the panel size: along the strike of the ore body, a panel is divided every 120 - 200 m, the panel dip length is 100 m, the panel height is 30 - 40 m, an 8.0 - m - wide panel isolation ore pillar is provided between each panel, and a 4.0 - m intermediate - level ore pillar is left between the upper and lower panels.

[0018] Further, in Step 2, four stoping slices are arranged from top to bottom in each panel. According to the stability of the ore and rock and the allowable exposed space, the height of the stoping slice is determined to be 7.5 - 10 m. A slice stoping roadway is directly driven along the strike of the ore body every 7.5 - 10 m. The slice stoping roadway is generally arranged along the footwall of the ore vein.

[0019] Further, in Step 2, the cross - sectional dimensions of the trackless equipment access roadway, the ramp in the panel, and the slice stoping roadway are all 2.5 - 4 m × 2.5 - 4.0 m. In unstable sections, prestressed resin bolts + mesh support need to be adopted. The bolt spacing is 1.2 - 1.5 m, and the row spacing is 0.7 - 1.0 m. The net diameter of the panel ore pass is 3.0 m, and the bottom of the panel ore pass is connected to the off - vein intermediate - level haulage roadway or the cross - cut haulage roadway.

[0020] Further, in Step 3, to facilitate the entry and exit of the rock - drilling jumbo and the load - haul - dump (LHD) vehicle, the angles between the ore room, the ore pillar, and the slice stoping roadway are all 35°. After the ore rooms on both sides of the slice stoping roadway are mined, ore pillars with the same width as the ore room are left, mining one and leaving one, and so on in a cycle, so that the ore rooms and ore pillars in each stoping slice are arranged in a "fishbone" shape.

[0021] The beneficial effects of the present invention are as follows:

[0022] 1. The purpose of the present invention is to solve the problems existing in the mining of gently inclined to inclined medium - thick ore bodies in the prior art, and provide a mining method for gently inclined to inclined medium - thick ore bodies with simple technology, high mechanization level, large production capacity, high efficiency, less development and cutting work, and no collapse of the overlying rock strata or the ground surface after mining. While achieving efficient mining, the tailings sand can be fully utilized, and the upper ecological environment will not be affected. The mining of ore rooms and ore pillars is all carried out using large - scale mechanical equipment, with low labor intensity of workers, good safety, large production capacity, and high efficiency.

[0023] 2. In stoping, one ore room and one ore pillar are mined and left in turn, so that the ore rooms and ore pillars are arranged in a "fishbone" shape, which helps the entry and exit of equipment; no top and bottom pillars and room - and - pillar are left, with a high recovery rate and low ore loss and dilution rate.

[0024] 3. Adopting subsequent filling, using the selected tailings sand, waste rock and a certain proportion of cementing agent as filling materials can reduce the prominent problems such as land occupation, safety, and environmental protection caused by the stacking of tailings sand and waste rock.

[0025] 4. By adopting filling mining, the impact on the surrounding environment during mining can be effectively reduced, and the mining of special sections can be realized, such as mining under buildings, railways, and water bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a plan view of the mining method according to a specific embodiment of the present invention;

[0027] Figure 2 is Figure 1 a sectional view taken along line A - A;

[0028] Figure 3 It is a schematic structural view of the pseudo - dip arrangement of the ore vein;

[0029] Figure 4 It is a process sequence diagram of stoping;

[0030] Wherein: 1 - cross - cut haulage roadway outside the ore vein, 2 - cross - cut haulage roadway in the level, 3 - panel ore pass, 4 - slicing stoping roadway, 5 - panel ramp, 6 - ore pillar to be mined, 7 - level ore pillar, 8 - ramp outside the panel, 9 - access roadway for trackless equipment, 10 - barrier ore pillar; 11. Rock - drilling jumbo; 12. LHD; 13. Filling pipeline; 14. Filling and drainage partition wall; 15. Filling body. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the accompanying drawings herein can be arranged and designed in various different configurations.

[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0033] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "first", "second", etc. are only used for descriptive distinction and cannot be construed as indicating or implying relative importance.

[0034] In the description of the embodiments of the present invention, it should be noted that the orientation or positional relationship indicated by terms such as "inner", "outer", "upper", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the invention product is habitually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention.

[0035] Embodiment 1

[0036] This technology is mainly aimed at inclined to gently inclined ore bodies with an ore body dip angle of 15° to 50°. For ore bodies with a dip angle below 15°, this method can be directly adopted. This embodiment provides a room-and-pillar mining subsequent filling mining method for gently inclined to inclined ore bodies, including the following steps:

[0037] Step 1: Determine the working face layout method

[0038] An air return roadway and a transportation roadway are respectively arranged along the strike above and below the stoping working face to form channels for ventilation, transportation, and pedestrian passage between the stoping working face and the upper and lower roadways. Since the ore body dip angle is 15° to 50°, the ramp in the middle panel area is directly arranged along the dip direction of the ore body. Due to the limited climbing ability of mechanical equipment such as rock drifters and load-haul-dumpers, they cannot reach the upper working roadway. Therefore, the middle working roadway needs to be arranged pseudo-inclined along the ore vein to reduce the slope.

[0039] As Figure 3 For the principle of pseudo-inclined layout, AD is the pseudo-dipping working face, ∠ACB is the true dip angle, that is, the ore bed dip angle α, ∠DAC is the pseudo-dip angle, ∠ADC is the angle between the pseudo-inclined working face and the strike direction, simply referred to as the strike angle, L_true is the true inclined length, L_pseudo is the pseudo-inclined length, the DC direction is the working face strike advancing direction, the AC direction is the dip direction, 1 is the upper boundary of the ore body, and 2 is the lower boundary of the ore body.

[0040] Step 2: Layout of development and cut-off roadways:

[0041] The gently inclined to inclined medium-thick ore body is divided into several panels along the strike. Each panel is divided into multiple stoping slices from top to bottom. In each stoping slice, a stoping roadway is arranged along the strike of the ore body. First, enter the bottom of the panel through the ramp 8 outside the panel and the trackless equipment access roadway 9, and develop the ramp 5 within the panel for connecting each stoping roadway along the trackless equipment access roadway 9. The ramp 5 within the panel is generally arranged along the footwall of the ore vein. Considering the climbing ability of equipment such as rock drilling jumbo and load-haul-dumper, the ramp 5 within the panel shall not exceed 15°. The ramp 5 within the panel adopts a zigzag layout within the panel, and a panel ore pass 3 is arranged at the isolation ore pillar near the turning point. The bottom of the panel ore pass 3 is connected to the cross-cut haulage roadway 1 outside the vein or the cross-cut haulage roadway 2 in the middle section.

[0042] Panel dimensions: Along the strike of the ore body, a panel is divided every 120 - 200 m, the inclined length of the panel is 100 m, the height of the panel is 30 - 40 m, and there is a panel isolation ore pillar 10 with a width of 8.0 m between each panel. A 4.0 m middle section ore pillar 7 is left between the upper and lower panels.

[0043] Each panel is provided with four stoping slices from top to bottom. According to the stability of the ore and rock and the allowable exposed space, the height of the stoping slice is determined to be 7.5 - 10 m. Every 7.5 - 10 m, a slice stoping roadway 4 is directly driven along the strike of the ore body. The slice stoping roadway 4 is generally arranged along the footwall of the ore vein.

[0044] The cross-sectional dimensions of the trackless equipment access roadway 9, the ramp 5 in the panel, and the slice stoping roadway 4 are all 2.5 - 4 m × 2.5 - 4.0 m (determined according to the rock drilling jumbo and load-haul-dump equipment and the stability of the ore and rock). In unstable sections, prestressed resin bolts + wire mesh support need to be adopted. The bolt spacing is 1.2 - 1.5 m, and the row spacing is 0.7 - 1.0 m. The net diameter of the panel ore pass 3 is 3.0 m. The bottom of the panel ore pass 3 is connected to the off-vein middle section transport roadway 1 or the cross-cut transport roadway 2. The ore room is arranged as follows Figure 1 、 Figure 2 as shown.

[0045] Step 3: Stoping

[0046] The stoping sequence is along the strike direction of the ore seam. In the panel, the top-down progressive slicing stoping method is adopted. In each stoping slice, the ore rooms and ore pillars are arranged continuously and alternately. Stoping is carried out in the way of mining one and leaving one. After the stoping of the ore room is completed, backfilling is carried out immediately. After the ore rooms on both sides of the ore pillar are backfilled and cured, the ore pillar is mined (specifically, the method of mining one and leaving one is as follows Figure 4 as shown, first mine ore room one. After the stoping of ore room one is completed, backfilling preparation is carried out. After leaving the ore pillar, mine ore room two. When mining ore room two, backfill ore room one. After the backfilling and curing of ore room one are completed, when mining ore room three, backfill ore room two. After the backfilling and curing of ore room two are completed, mine ore pillar one in the second step);

[0047] Each stoping slice includes the upper part, the lower part, and the middle stoping roadway. The first slice mainly mines the lower part, and the upper part leaves the middle section ore pillar without mining. For each of the remaining stoping slices, first mine the upper part of this stoping slice in the stoping roadway of the upper stoping slice, and then mine the lower part of the upper stoping slice in the stoping roadway of the lower stoping slice;

[0048] Since the ore room is 5 m long and its inclined length is 11.6 m, for the convenience of the rock drilling jumbo 11 and the load-haul-dump 12 to enter and exit, the included angles between the ore room, the ore pillar, and the slice stoping roadway 4 are all 35°. After the stoping of the ore rooms on both sides of the slice stoping roadway 4 is completed, ore pillars with the same width as the ore room are left, mining one and leaving one, and so on in a cycle, so that the ore rooms and ore pillars in each stoping slice are arranged in a "fishbone" shape.

[0049] The blast holes are drilled by a jumbo. Medium-deep hole drilling is adopted, and medium-deep hole drilling is carried out in the sectional drilling roadway. The mining jumbo drills medium-deep holes along the full section of the ore room. The diameter of the blast holes is ф76mm, the row spacing of the blast holes is 1.5m to 2m, and the hole bottom distance is 3m to 4m. One to two rows of holes are blasted at a time. If the stability of the ore and rock is relatively low, a roadheader can also be directly used for cutting and stoping instead of a rock drill. After blasting, ventilation is carried out to remove the blast fumes. After passing the inspection, a load-haul-dump machine enters the stope for loading. After loading, it is transported to the panel ore pass and directly unloaded into the ore pass;

[0050] Step Four: Backfilling

[0051] After stoping is completed, backfilling preparation work is carried out immediately. A filling drainage partition wall 14 is set at the intersection of the stratified stoping roadways in the mined ore room, and a corrugated filter water pipe 13 is laid along the bottom to the filling drainage partition wall 14 and passes through the filling drainage partition wall 14 to drain the seepage water of the filling body in the stope; the curing time of the filling body is 3 to 4 months.

[0052] Specifically, after the block stoping is completed, backfilling preparation work is carried out immediately. The main work of stope backfilling preparation is to do a good job in the airtight work of the stope to separate the entire stope from all surrounding roadways to prevent the loss and pollution of the backfill material. The filling drainage partition wall is set at the intersection of the mined ore room and the sectional drilling roadway.

[0053] The corrugated filter water pipe 13 runs from the filling station to the upper haulage roadway and is laid through the ramp 5 in the connection panel to the stratified stoping roadway 4. Before backfilling, carefully check the entire filling pipeline system to ensure that the filling control valve opens and closes sensitively, the pipeline is intact and unblocked. A corrugated filter water pipe 13 is laid along the bottom of the ore room to be filled to the filling drainage partition wall 14 and passes through the filling drainage partition wall 14 to drain the seepage water of the filling body in the stope. The backfilling is carried out in stages. To prevent the accident of slurry leakage and reduce the pressure of the filling body on the partition wall, generally 2m to 3m of backfill material is filled first, and then filled successively after initial setting until the stope is full. The curing time of the filling body is 3 to 4 months.

[0054] For the local filling working face where the roof is not fully connected, after the entire stratified stoping is completed, the roof connection filling is carried out from the equipment connection ramp.

[0055] For the roadway driving and mining used in this technology, the drill and blast method is preferably adopted. When the strength of the ore and rock is low, a medium-thick ore body that can be directly cut and stoped by a roadheader can also use this method, and the layout form of the development roadways, stoping, ore drawing, and backfilling methods remain unchanged.

Claims

1. A subsequent filling mining method for room-and-pillar mining of gently inclined to inclined ore bodies, characterized in that, It includes the following steps: Step 1: Determine the layout mode of the working face An air return gateway and a haulage gateway are respectively arranged along the strike above and below the longwall face to form channels for ventilation, haulage and pedestrian traffic between the longwall face and the upper and lower gateways; The longwall face advances along the strike. When the dip angle of the ore seam is less than 15°, the working face is arranged along the true dip direction; when the dip angle of the ore seam is 15° - 50°, the working face is arranged in a pseudo - dip direction, and the pseudo - dip angle is determined according to the climbing ability of the rock drilling and ore drawing equipment, which is 5° - 25°; Step 2: Layout of the development and cut - through roadways The gently inclined to inclined medium - thick ore bodies are divided into several panels along the strike. Each panel is divided into multiple stoping slices from top to bottom. In each stoping slice, there are stoping roadways along the strike of the ore body. First, enter the bottom of the panel from the external ramp (8) of the panel through the trackless equipment access roadway (9), and develop the internal ramp (5) of the panel for connecting each stoping roadway along the trackless equipment access roadway (9); the internal ramp (5) of the panel is arranged along the footwall of the ore vein; the gradient of the internal ramp (5) of the panel shall not exceed 15°. The internal ramp (5) of the panel adopts a reversing layout in the panel, and a panel ore pass (3) is arranged at the isolation ore pillar near the turning point. The bottom of the panel ore pass (3) is connected with the cross - cut haulage roadway (1) or the cross - cut haulage roadway in the middle section (2); Step 3: Stoping The stoping sequence is along the strike direction of the ore seam. In the panel, the top - down progressive slicing stoping method is adopted. In each stoping slice, the ore rooms and ore pillars are arranged continuously at intervals. Stoping is carried out by the method of mining one and leaving one. After the stoping of the ore room is completed, backfilling is carried out immediately. After the ore rooms on both sides of the ore pillar are backfilled and cured, the ore pillar is mined; Each stoping slice includes the upper part, the lower part and the middle stoping roadway. In the first slice, the lower part is mainly mined, and the upper part is left with a middle - section ore pillar without mining; in each of the remaining stoping slices, the upper part of the current stoping slice is mined first in the stoping roadway of the upper stoping slice, and the lower part of the upper stoping slice is mined in the stoping roadway of the lower stoping slice; In the said Step 3, for the convenience of the rock drilling jumbo (11) and the load - haul - dump (LHD) (12) to enter and exit, the included angles between the ore room, ore pillar and the slice stoping roadway (4) are all 35°. After the stoping of the ore rooms on both sides of the slice stoping roadway (4), ore pillars with the same width as the ore room are left, mining one and leaving one, and so on in a cycle, so that the ore rooms and ore pillars in each stoping slice are arranged in a "fishbone" shape; Step 4: Backfilling The corrugated filter water pipe (13) is laid from the charging station to the upper haulage level, and then through the internal ramp (5) in the connecting panel to the slice stoping roadway (4); after the stoping is completed, the backfilling preparation work is carried out immediately. A backfilling water - drainage partition wall (14) is set at the intersection of the stoping roadways in the mined slices, and the corrugated filter water pipe (13) is laid along the bottom to the backfilling water - drainage partition wall (14) and passes through the backfilling water - drainage partition wall (14) to drain the seepage water of the backfill in the stope; The backfilling is carried out in stages. First, 2 - 3 m of backfill material is filled. After initial setting, backfilling is carried out successively until the stope is full; the curing time of the backfill is 3 - 4 months.

2. The subsequent filling mining method for room-and-pillar mining of gently inclined to inclined ore bodies according to claim 1, characterized in that, In Step 2, the panel size: along the strike of the orebody, a panel is demarcated every 120 - 200 m, the panel dip length is 100 m, the panel height is 30 - 40 m, an 8.0 - m - wide panel isolation ore pillar (10) is provided between each panel, and a 4.0 - m - high - level ore pillar (7) is left between the upper and lower panels.

3. The subsequent filling mining method for room-and-pillar mining of gently inclined to inclined ore bodies according to claim 2, characterized in that, In Step 2, four stoping slices are set from top to bottom in each panel. According to the stability of the ore and rock and the allowable exposed space, the height of the stoping slice is determined to be 7.5 - 10 m. A slice stoping roadway (4) is directly driven along the strike of the orebody every 7.5 - 10 m, and the slice stoping roadway (4) is arranged along the footwall of the ore vein.

4. The subsequent filling mining method for room-and-pillar mining of gently inclined to inclined ore bodies according to claim 1, characterized in that, In Step 2, the cross - sectional dimensions of the trackless equipment access roadway (9), the ramp in the panel (5), and the slice stoping roadway (4) are all 2.5 - 4 m × 2.5 - 4.0 m; in unstable sections, prestressed resin bolts + wire mesh support need to be adopted, the bolt spacing is 1.2 - 1.5 m, the row spacing is 0.7 - 1.0 m, the net diameter of the panel ore pass (3) is 3.0 m, and the bottom of the panel ore pass (3) is connected to the off - vein level haulage roadway (1) or the cross - cut haulage roadway (2).

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