A method of mining a stage top and bottom pillar

Abstract

The application discloses a stage top and bottom pillar stoping method and belongs to the field of metal mine mining engineering. The method is based on the application of the stage empty field subsequent filling method in the steeply inclined thick ore body, and after the stoping and filling of the upper and lower stage ore rooms are completed, the upward slicing drift strip filling method and the vertical upward fan-shaped hole method are combined to stop the top and bottom pillars between the two stages. The method can safely and efficiently stop the pillars on the basis of the stoping and filling of the upper and lower stage ore rooms, so that the loss of the ore is reduced.

Description

Technical Field

[0001] This invention relates to a method for recovering top and bottom pillars in stages, belonging to the field of underground mining technology for metal deposits. Background Technology

[0002] In the downward mining of steeply dipping, thick ore bodies, the staged stope subsequent backfilling method is adopted. After the backfilling of the previous stage stope is completed, a certain thickness of top and bottom pillars is reserved as the roof of the next stage stope to ensure safety during its mining. After the backfilling and mining of the two stages are completed, staged top and bottom pillars will remain. To ensure the mining of the staged top and bottom pillars in the future, the stage stopes in steps I / II are backfilled with highly cemented backfill at the top and bottom, and with low-cemented backfill or tailings backfill in the middle part of the stope. This invention is a method for mining staged pillars based on this technical background. Summary of the Invention

[0003] The purpose of this invention is to provide a method for mining staged top and bottom pillars. In steeply dipping, thick ore bodies, staged open spaces are subsequently filled. To achieve rapid production, downward mining is generally adopted. This results in pillars of a certain thickness being reserved between the two stages after the mining of the previous stage stope is completed, in order to ensure the safety of the roof during the mining of the next stage stope. After the mining and filling of the next stage are completed, top and bottom pillars between the two stages and peach-shaped pillars between the top and bottom of the adjacent stopes in the previous stage are left behind, causing ore loss. This invention mines these two types of pillars through vertical upward fan-shaped holes and upward layered access strips, specifically including the following steps:

[0004] (1) Pillar division: The top and bottom pillars are divided into two mining units. That is, the pillars corresponding to the bottom trench of the stope are one mining unit, and the peach-shaped pillars in the middle of the bottom of adjacent stops in the same stage and the corresponding top and bottom pillars of the stage are another mining unit.

[0005] (2) Arrange the entry strips corresponding to the pillars at the bottom of the stope and mine in layers from bottom to top until the bottom of the stope is mined. After each layer is mined, low-cement filling is carried out, followed by high-cement surface filling. During mining, the top elevation of the next stope is cut off and the detour is arranged along the vein roadway to each layer. After each layer is mined, the top is brushed and the detour outside the vein is raised, and then compacted and leveled.

[0006] (3) The peach-shaped pillar and the corresponding lower stage top and bottom pillars are divided into two parts for mining. During mining, the upper layered entry method is used to mine the corresponding pillars at the bottom of the stope first, and cemented backfilling is carried out after the mining is completed. Then, the peach-shaped pillar and the corresponding lower pillars are mined, and tailings backfilling is carried out after the mining is completed.

[0007] In the next stage, a bypass is arranged along the vein from the top elevation of the stope to the middle position of the bottom of the stage pillar, and a drilling roadway is arranged perpendicular to the ore body strike. This roadway serves as the drilling roadway at the bottom of the mining unit and the main access road for ore extraction during mining of adjacent mining units. The drilling roadways at the bottom of each mining unit are arranged perpendicular to the ore body strike at intervals of 6-7m. At the bottom elevation of the stope in the previous stage, a mining access roadway is arranged perpendicular to the ore body strike at the center line of the peach-shaped pillar. This roadway is used to clear the cemented backfill in the ore extraction roadway of the previous stage stope and serves as the drilling roadway for mining the peach-shaped pillar.

[0008] (4) Using the bottom drilling chamber roadway, cut the riser to the peach-shaped pillar at its side and pull the groove; after the groove is completed, vertical upward fan-shaped holes are arranged in the upper and lower drilling roadways respectively, and millisecond micro-delay blasting is used to squeeze back the mining in the direction of the cut groove, and the ore is extracted by using the bottom ore extraction entrance between the mining units.

[0009] (5) After mining is completed: retaining walls are set up at the ore access road and bypass passage. Filling holes are drilled along the vein roadway at the bottom of the previous stage stope to the peach-shaped pillar. Tailings are filled into the mining unit.

[0010] Preferably, in step (1) of the present invention, the access strip is arranged with a trench width of 3m and a height of 4m.

[0011] Preferably, the thickness of the low-cement filling in step (1) of the present invention is 2.5 to 3.5 μm, and the compressive strength reaches 1 to 1.5 MPa.

[0012] Preferably, in step (1) of the present invention, the thickness of the high-bonding surface layer is 0.5 μm, and the compressive strength reaches 1.5–2 MPa.

[0013] Preferably, the detour slope in step (1) of the present invention is 10% to 12%.

[0014] In step (3) of this invention, after the backfilling is completed using the approach method, the bottom of the peach-shaped pillar between two adjacent stops and the corresponding lower pillar are backfilled with tailings using vertical upward fan-shaped holes. When a peach-shaped pillar and its lower pillar are backfilled as a backfilling unit, the deep-hole drilling roadway in the lower part of the adjacent un-backfilled unit of the same type serves as the main access road for the ore-producing backfilling unit. The ore-producing access road between the two units passes through the lowest access road strip.

[0015] The top and bottom pillar mining method described in this invention uses a loader for ore extraction, with appropriate additions to the preparatory work, and utilizes the existing staged ore extraction system. In locations or sections far from the ore pass, 15-20 t trucks can be used in conjunction with the loader for ore extraction.

[0016] The method for recovering pillars described in this invention uses an upward-layered, layered strip filling method for the recovery of some pillars. The recovery roadway is a single-ended roadway, and a combination of suction and pressure ventilation can be used. The peach-shaped pillar recovery unit can be ventilated along the vein by excavating a short shaft at the end of the mining trunk line to the next stage stope cut-off top elevation.

[0017] The method described in this invention involves two environmental conditions:

[0018] (1) There is no ridge-like residual ore in the bottom ditch of the upper stage stope. When mining to the uppermost layer, the filling body of the bottom ditch can be exposed.

[0019] (2) There are residual ore on the bottom plate of the trench at the bottom of the previous stage. The mining height of the corresponding access strip at the bottom of the trench should be appropriately reduced by 0.5 to 1m so that a certain thickness of ore pillar is reserved in the middle to avoid the exposure of residual ore on the ridge due to the exposure of the bottom trench, which may cause safety hazards.

[0020] Beneficial effects of this invention:

[0021] The method described in this invention is a method for recovering the top and bottom pillars between stages after the staged open-stope filling method is completed in steeply inclined ore bodies, under the premise of ensuring safety and efficiency. It solves the problem of permanent loss of stage pillars caused by mining technology and pillar occurrence conditions, and greatly improves the ore recovery rate. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view along the strike of the ore body, representing the invention.

[0023] In the diagram: 1 - Highly cemented backfill at the top of the stage stope; 2 - Cemented stope in step I; 3 - Peach-shaped pillar; 4 - Peach-shaped pillar drilling roadway; 5 - Upward-slicing access strip; 6 - Uncemented stope in step II; 7 - Backfill at the bottom of the stage stope; 8 - Mining unit; 9 - Backfill retaining wall; 17 - Top and bottom pillars of the stage stope.

[0024] Figure 2 This is a cross-sectional view along the strike of the ore body, representing the invention.

[0025] 1-Highly cemented backfill at the top of the stope in stage 1; 2-Cemented stope in step I; 3-Peach-shaped pillar; 4-Drilling roadway below the peach-shaped pillar; 10-Ore access roadway at the bottom of the stope in stage 10; 11-Vein roadway along the hanging wall of the upper stage; 12-External bypass; 13-Vein roadway along the hanging wall of the lower stage; 14-Cutting riser; 15-Vein roadway along the hanging wall of the lower stage; 16-Drilling roadway for the top and bottom pillars of stage 10; 17-Top and bottom pillars of stage 10; 18-Ore access roadway for the mining unit. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0027] A domestic mine has an ore body with a dip angle of 72°–80° and a horizontal thickness of 38–40m. It employs a staged open-stope and subsequent backfilling method in steps I / II for continuous mining. The stops are arranged perpendicular to the strike of the ore body. In step I (cemented stope 2) and step II (uncemented stope 6), the top 1 and bottom 7 are filled with 1:4 cemented material, while the middle of the stopes is filled with 1:10 cemented material or tailings. The bottom trench of the stopes is 3m wide and has no residual ore on the ridge. A 12m thick top and bottom pillar is reserved between adjacent stage stops, and a peach-shaped pillar of approximately 9m remains between the bottoms of adjacent stops in the same stage. The following plan is made for the above two parts of the top and bottom pillars, and mining will proceed accordingly.

[0028] Example 1

[0029] A method for staged top and bottom pillar recovery, such as Figure 1 and 2 Specifically, it includes the following steps:

[0030] (1) Arrange the corresponding pillars at the bottom of the stope with a trench width of 3m and a height of 4m in a roadway-type strip, and mine in layers from bottom to top until the bottom of the stope bottom trench filling body 7 is reached; after each layer is mined, a 3.5m thick low-cement filling layer with a compressive strength of 1 to 1.5 MPa is carried out, followed by a 0.5m thick high-cement surface layer filling with a compressive strength of 1.5 to 2 MPa; during mining, a bypass is arranged along the vein roadway from the top elevation of the next stope to each layer. After each layer is mined, the top is brushed and raised outside the vein bypass 12, compacted and leveled to create conditions for the upper layer access mining. The slope of the bypass should be controlled at 11%.

[0031] (2) After the strip mining and backfilling of the access road is completed, the peach-shaped pillar 3 and the lower stage top and bottom pillars 17 are mined by vertical upward fan-shaped holes, and they are treated as a mining unit 8. Among them, the bottom of the peach-shaped pillar is provided with the bottom ore access road 10 of the stage stope, and the interior is filled with 1:4 cemented backfill. In order to reduce the dilution of the pillar recovery, the backfill needs to be cleaned during mining.

[0032] (3) According to the mining requirements described in step (2), the peach-shaped pillar and the corresponding stage top and bottom pillars 17 are divided into two parts for mining. A bypass roadway 13 is arranged along the vein in the lower stage to the middle position of the bottom of the stage top and bottom pillars 17, and a drilling roadway 16 is arranged perpendicular to the ore body direction to serve as the main line for mining when the peach-shaped pillar and the top and bottom pillar mining unit 8 are mining. The drilling roadway at the bottom of each mining unit is arranged at a distance of about 6-7m perpendicular to the ore body direction. A mining preparation roadway is arranged perpendicular to the ore body direction at the bottom mining elevation of the upper stage stope along the vein and at the center position of the peach-shaped pillar to clear the cemented backfill in the mining roadway of the upper stage stope and serve as the drilling roadway for mining the peach-shaped pillar. When mining unit 8, the lower part is the high cemented backfill 1 at the top of the stage stope, whose strength can meet the operation of the trackless equipment during pillar mining.

[0033] (4) Using the bottom drilling chamber roadway, cut wells 14 are arranged on its side to the peach-shaped pillar 3 for slotting; after slotting is completed, vertical upward fan-shaped holes are arranged on the peach-shaped pillar drilling roadway 4 and the stage top and bottom pillar drilling roadway 16 respectively, and millisecond micro-delay blasting is used to squeeze back mining in the direction of the cutting groove, and ore is extracted by using the bottom ore extraction entrance in the mining unit 8.

[0034] (5) After the mining is completed, a backfilling retaining wall 9 is arranged at the entrance of the mining unit 18 and the bypass 12. A backfilling hole is drilled in the upper plate along the vein roadway 11 to the peach-shaped pillar 3, and the tailings are backfilled in the mining unit.

Claims

1. A method for mining staged top and bottom pillars, characterized in that, Specifically, the following steps are included: (1) Pillar division: The top and bottom pillars are divided into two mining units. That is, the pillars corresponding to the bottom trench of the stope are one mining unit, and the peach-shaped pillars in the middle of the bottom of adjacent stops in the same stage and the corresponding top and bottom pillars of the stage are another mining unit. (2) Arrange the approach strips corresponding to the pillars at the bottom of the stope and mine in layers from bottom to top until the bottom of the stope is mined. After each layer is mined, low-cemented filling is carried out, followed by high-cemented surface filling. During mining, the top elevation of the next stope is cut off and the bypass is arranged along the vein roadway to each layer. After each layer is mined, the top is brushed and the bypass is raised outside the vein, and then compacted and leveled. (3) Divide the peach-shaped pillar and the corresponding stage top and bottom pillars below it into two parts for mining. At the top elevation of the lower stage stope, arrange a bypass along the vein upward to the middle position of the bottom of the stage top and bottom pillars, and arrange a drilling roadway perpendicular to the ore body strike. This roadway serves as the drilling roadway at the bottom of the mining unit and the main line for ore extraction during mining of adjacent mining units. The drilling roadway at the bottom of each mining unit is arranged at intervals of 10-14m perpendicular to the ore body strike. At the bottom elevation of the upper stage stope, arrange a mining roadway perpendicular to the ore body strike along the center line of the peach-shaped pillar. This roadway is used to clear the cemented backfill in the upper stage stope's ore extraction roadway and serves as the drilling roadway for mining the peach-shaped pillar. (4) Using the bottom drilling chamber roadway, cut the riser to the peach-shaped pillar at its side and pull the groove; after the groove is completed, vertical upward fan-shaped holes are arranged in the upper and lower drilling roadways respectively, and millisecond micro-delay blasting is used to squeeze back the mining in the direction of the cut groove, and the ore is extracted by using the bottom ore extraction entrance between the mining units. (5) After the mining is completed: retaining walls are set up at the entrance of the mining road and the bypass. Filling holes are drilled along the vein roadway at the bottom of the previous stage stope to the peach-shaped pillar. Tailings are filled into the mining unit. In step (2), access strips are laid out according to a trench width of 3m and a height of 4m; In step (2), the thickness of the low-cement filling is 3.5m, and the compressive strength reaches 1 to 1.5 MPa; In step (2), the thickness of the high-bonding surface layer is 0.5m, and the compressive strength reaches 1.5~2Mpa.

2. The method for mining staged top and bottom pillars according to claim 1, characterized in that: In step (2), the detour slope is 10% to 12%.

Images