Downward segmented spindle-shaped open stoping subsequent cemented filling mining method

Abstract

The invention discloses a downward segmented spindle-shaped open stope subsequent cemented filling mining method, belongs to the technical field of mining, and is particularly suitable for a soft broken thick and large steep ore body. The method comprises the following steps: firstly, mining at least three layers at the top position of the ore body by adopting a downward layered access cemented filling method, and forming an initial false roof for the whole stope; mining is carried out under the initial false roof by adopting downward segmented spindle-shaped open stoping subsequent cemented filling, stoping is carried out segment by segment from top to bottom during stoping, stoping drifts between upper and lower adjacent segments are staggered in a shape like a Chinese character'pin ', upward spindle-shaped gun rows are arranged in the drifts of all the segments, stoping is carried out from an upper wall to a lower wall to form chambers, and the chambers are separated from the upper wall to the lower wall; the caved ore in the chamber is transported out by the remote control carry-scraper, and the filling air return duct at the top of the chamber can realize filling, air return and the like on the chamber; according to the mining method disclosed by the invention, non-pillar continuous efficient stoping can be realized along the trend and the vertical direction of the ore body, and the mining efficiency and the mining operation safety are improved on the basis of effectively controlling the ground surface settlement.

Description

Technical Field

[0001] The present invention relates to the technical field of mining, and particularly to a downward sublevel spindle-shaped open stoping and subsequent cemented filling mining method. Background Art

[0002] How to achieve the safe and efficient mining of soft, thick, steeply dipping ore bodies has always been a technical problem in the mining industry. In order to achieve the efficient and low dilution mining of such ore bodies while maintaining the stability of the stope, cemented filling methods are usually used for mining. Commonly used cemented filling methods include the downward slicing drift cemented filling method and the stage open stoping and subsequent cemented filling method, etc. When using the downward slicing drift cemented filling method for mining, the small exposed area of the stope void is beneficial to maintaining the stability of the stope. However, this method uses shallow-hole ore drawing, resulting in low mining efficiency and inability to achieve large-scale and efficient mining of the ore body. While the stage open stoping and subsequent filling method uses large-diameter deep-hole ore drawing, and the mining efficiency is significantly improved. However, due to the large exposed area of the rectangular stope void, especially the two vertical side walls of the first-step stope are broken ore bodies, it is difficult to form a stope, thus affecting the normal application of this method under broken ore and rock conditions.

[0003] Therefore, it is necessary to develop a new type of cemented filling mining method that can achieve the safe and efficient mining of soft, thick, steeply dipping ore bodies, thereby enhancing the technical and economic benefits of mine mining. Summary of the Invention

[0004] The object of the present invention is to provide a downward sublevel spindle-shaped open stoping and subsequent cemented filling mining method to solve the above problems.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A downward sublevel spindle-shaped open stoping and subsequent cemented filling mining method includes the following steps: (1) First, at least three slices are mined at the top position of the ore body by using the downward slicing drift cemented filling method to form an initial false roof for the entire stope; It should be noted that the "downward slicing drift cemented filling method" in this step refers to the well-known conventional (traditional) downward slicing drift cemented filling method, such as enterprise standard Q / YSJC-GY04-2010. (2) Below the initial false roof, downward sublevel spindle-shaped open stoping and subsequent cemented filling are used for mining. During mining, the sublevels are mined from top to bottom one by one, and the mining drifts between adjacent upper and lower sublevels are arranged in a "pin" shape in a staggered manner, so that the shape of the ore room formed by the first mining is a semi-"spindle" shape, and the shapes of the ore rooms formed by the mining of the remaining drifts are "spindle" shapes. Compared with the traditional "staged open stoping with subsequent backfilling method", the differences in this step are reflected in that the sublevel stoping headings are arranged in a "pin" shape. In addition, the ore rooms formed by the traditional staged open stoping with subsequent backfilling method are rectangular ore rooms, while the ore rooms formed by this method are spindle-shaped. (3) Arrange upward spindle-shaped blast rows in the headings of each sublevel. The blast row in the first mined sublevel is a semi-spindle-shaped blast row. Use the upward blast rows to carry out ore caving retreat mining row by row from the hanging wall to the footwall to form an ore room with the same shape as the blast row. The ore room is filled in two times with cementitious materials of different strengths for the upper half and the lower half respectively. (4) After the cemented filling body of the previous ore room is stable, cut a raise in the stoping heading upward adjacent to the filling body. Use this raise as the blasting compensation space to complete the initial slotting operation of the subsequent ore room. Then, retreat mining is carried out row by row of blasts to form a new spindle-shaped ore room and fill it. Repeat this cycle until a heading is completely retreated and mined out.

[0006] As a preferred technical solution, in step (2), both the sublevel height and the heading spacing are 15 - 20 m. The effect of controlling the sublevel height and the heading spacing within 15 - 20 m is that it can effectively increase the single ore caving volume, and the single ore caving volume can reach more than 10 times that of the heading cemented filling method, but it will not make the ore room size too large to reduce the stability of the ore room.

[0007] As a preferred technical solution, in step (2), a cross-cut filling and return airway is arranged at the top of the ore room for filling and air return of the stope. The advantage of arranging the filling and return airway at the top of the ore room is that it can ensure that the polluted air in the ore room can be timely removed, and at the same time, the filling material is released from a high position, which is beneficial to achieving filling up the top of the ore room.

[0008] As a preferred technical solution, in step (3), the blast row step distance is 2 - 4 m.

[0009] As a preferred technical solution, in step (3), the lower half of the ore room is filled with a cementitious material with a compressive strength of 3 - 5 MPa. After the lower half filling body solidifies, the upper half is filled, and the upper half is filled with a cementitious material with a compressive strength of 1 - 2 MPa.

[0010] The strength of the above-mentioned bonding material specifically refers to: the lower part of the mine room is filled with filling materials with a 28d compressive strength of 3 to 5MPa. After the filling body of the lower part reaches initial setting (after 3d), the upper part of the mine room is filled with filling materials with a 28d compressive strength of 1 to 2MPa. The advantage of this is that the filling body of the lower part of the mine room in this section is the direct roof of the lower section mine room. Therefore, the use of higher-strength filling body in the lower part of the mine room can ensure the stability of the roof of the lower section mine room, while the strength requirement of the filling body in the upper part of the mine room is not that high. At this time, the use of lower-strength filling materials can reduce the filling cost, which is beneficial to improving the economic benefits of mining.

[0011] As a preferred technical solution, in step (3), except for the first mining section whose length is 10 to 15 m, the length of the other section mine rooms can be increased to 20 to 30 m. The advantage of this is that, considering that the first mining section mine room is semi-spindle-shaped and the mine room roof is flat, it is more susceptible to tensile stress damage. Therefore, in order to ensure the stability of the mine room, it is advisable to appropriately reduce the length of the first mining section mine room, and it is recommended to take 10 to 15 m. The other section mine rooms are spindle-shaped, and the shape of the mine room is conducive to the distribution of ground pressure and maintaining the stability of the mine room. Therefore, in order to improve mining efficiency, it is recommended to increase the size of the mine room to 20 to 30 m.

[0012] As a preferred technical solution, in step (3), multiple approaches in the same segment are operated simultaneously. In order to control the exposed area of ​​the roof, adjacent approaches in the segment are divided into a first-step stope and a second-step stope for alternating mining. The first-step stope is at least one mine room ahead of the second-step stope, and adjacent approaches cannot be mined simultaneously in the horizontal direction.

[0013] The method of the present invention is particularly suitable for mining soft, broken, thick, steep ore bodies, and can achieve continuous and efficient mining without pillars along the strike and vertical direction of the ore body.

[0014] Compared with the traditional downward layered approach cementation filling method, the application adopts large-diameter deep holes for ore dropping and centralized ore discharge in the mine room, which can realize multi-access and multi-segment mining at the same time, and its recovery efficiency will be more than twice that of the traditional downward layered approach cementation filling method; and corresponding to the traditional staged empty field subsequent filling method, the mine room of this application is spindle-shaped, the mine room roof is a cementation filling body, and the oblique sides on both sides of the lower part of the mine room are stable ore bodies that achieve a natural resting angle. The mine room shape is more conducive to ground pressure distribution and self-stabilization.

[0015] Compared with the prior art, the advantages of the present invention are: (1) This method has a low ore loss rate. During the mining process, no ore pillars will remain in the mining area, thus ensuring sufficient recovery of the ore; (2) This method has a large production capacity. It uses large-diameter deep holes to mine and has a high production capacity. Its mining capacity will be more than twice that of the layered approach cementing filling method. (3) This method has high mining efficiency. It can realize simultaneous mining of multiple access routes in a single segment, and can also realize simultaneous mining of multiple segments, thereby achieving efficient mining. After high-intensity ore dropping in medium-deep holes, the mine room is centrally filled, which also improves the filling efficiency; (4) This method has a high degree of mechanization. The drilling, charging, ore extraction, filling and other links are all mechanized operations, which facilitates the realization of unmanned intelligent mining operations underground; (5) This method is safe. This method uses remote control shovel transportation to mine in the mine room. The ore is transported outside the mine room in a supported access road. In addition, rock drilling, charging, blasting and other operations are all carried out in the supported access road. The filling operation is carried out in a tunnel with limited exposed space and the roof is a false roof of the filling body. Therefore, all mining processes of this method are carried out in a safe and secure environment. (6) This method has good ventilation conditions and filling connection conditions. When this method adopts segmented mining, the mining area has good air intake and return conditions. In addition, the filling tunnel is located at the top of the mine room, and the filling material fills the mine room from top to bottom. In addition, the upper part of the spindle-shaped mine room is gradually reduced in an inverted "V" shape. Therefore, this method can ensure that the mine room has a good filling connection rate. At the same time, the remaining filling unconnected empty areas in each mine room will not accumulate or overlap in the horizontal or vertical direction. Therefore, this method has a better rock movement control effect than the conventional filling method; (7) The mine room of this method is stable and easy to form. In this method, the mine room is a spindle-shaped structure, which is more conducive to pressure distribution and can effectively reduce the stress concentration phenomenon in the mine room. In the entire mine room, the roof and waist of the mine room are cemented filling bodies with good integrity and stability. Only the two sides of the bottom of the mine room are ore bodies, but these two side walls are inclined at 50~60 degrees and are in a natural resting and stable state. At the same time, due to the existence of the two inclined walls at the bottom, the lower half of the mine room presents a "V" shape, which can play a role in gathering the collapsed ore in the mine room and is more conducive to the full shoveling of the ore; In summary, the mining method of the present invention can achieve continuous and efficient mining without pillars along the strike and vertical direction of the ore body, thereby improving the mining efficiency of soft, broken, thick, large and steep ore bodies, and at the same time improving the safety of mining operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the downward segmented spindle-shaped empty field and subsequent cementation and filling mining method of the present invention; Figure 2 for Figure 1 Ⅰ-Ⅰ sectional view; Figure 3for Figure 1 Ⅲ-Ⅲ cross-sectional view.

[0017] In the figure: 1. The first layered approach of the initial false roof; 2. The second layered approach of the initial false roof; 3. The third layered approach of the initial false roof; 4. The return air duct for filling through the vein; 5. The approach for segmented mining; 6. The spindle-shaped blast row; 7. The cutting skylight; 8. The filling retaining wall; 9. The filling pipeline; 10. The filling pipeline shaft; 11. The segmented lower wall connecting tunnel; 12. The ore chute of the mining area; 13. The staged transportation tunnel along the vein; 14. The cutting groove of the upper wall; 15. The first-step mining area; 16. The second-step mining area; 17. The surrounding rock; 18. The ore body; 19. The cemented filling body; 20. The collapsed ore. DETAILED DESCRIPTION

[0018] The present invention will be further described below in conjunction with the accompanying drawings. Example

[0019] A downward segmented spindle-shaped open-pit subsequent cementation and filling mining method is suitable for mining soft, broken, thick, steep ore bodies with high grade or high value. During mining, an initial false roof is first formed at the top of the ore body through downward layered access cementation and filling, and then a spindle-shaped ore room is used for subsequent filling mining in each segment downward. The method specifically includes the following steps: Before mining according to this method, at least three layers are mined at the top of the ore body using the downward layered approach cementation filling method to form an initial false roof for the subsequent filling mining of the lower segmented spindle-shaped open space; Figures 1 to 3 As shown ( Figure 1 for Figure 3 Ⅱ-Ⅱ sectional view), in this embodiment, they are initial false roof first layer approach 1, initial false roof second layer approach 2 and initial false roof third layer approach 3; when mining according to the downward layer approach type cemented filling method, the first layer and the second layer mining approach, i.e., the initial false roof first layer approach 1 and the initial false roof second layer approach 2, are both in the form of straight wall semicircular arch in cross section, with width × height = 4m × 4m, and single-layer anchor spraying network support is adopted. The spacing between adjacent mining approaches in the first layer is 4m, the bottom plate elevation of the initial false roof second layer approach 2 is 2.5m lower than the bottom plate elevation of the initial false roof first layer approach 1, and the initial false roof second layer approach 1 is located at the first Below the columns between adjacent mining routes of the layers; the cross-section of the third layered route 3 of the initial false roof is rectangular, with width × height = 4m × 2.5m, and is located directly below the bottom plate of the first layered route. Its route bottom plate is at the same elevation as the bottom plate of the second layered route. Since the top plate and both sides of the third layered route are cemented filling bodies 21, no support is required. After the three layers are mined and filled, an initial false roof can be formed for the entire mining field. However, it should be noted that when the second and third layered routes are mined, it is necessary to reserve the through-vein filling return air duct 4 according to the position of the first and second segmented mine rooms at the lower part, and fill it after completing the filling and return air missions of the lower mine room; After the initial false roof is formed, downward sublevel open stoping with subsequent backfilling is carried out under the false roof. The sublevel height and drift spacing are both 15 m, the stage height is 90 m, and the sublevel stoping drifts 5 between adjacent upper and lower sublevels are arranged in a staggered "pin" shape, so that the shape of the ore room formed by the stoping of each drift is "spindle-shaped" (the ore room in the first mined sublevel is semi-spindle-shaped); A cross-cut filling return airway 4 is arranged at the top of the ore room for filling and air return of the stope. The filling return airways in the first and second sublevels are the first and second stratified stoping drifts for forming the initial false roof, and their shapes are rectangular or straight-wall semi-circular arched; the filling return airways in the remaining sublevels are isosceles trapezoids with a height of 2.5 m, a top width of 4 m, and a bottom width of 6 m in the vein, and straight-wall semi-circular arched roadways of 2.5 m × 2.5 m outside the vein. The construction of this roadway sinks from the sublevel footwall cross-heading 11 at a slope of 10% and is arranged under the floor of the drift in the mined sublevel. After the in-vein section of this roadway is formed, except for the floor being ore, both the two waists and the roof are cemented filling bodies 21, so no support is required in the vein, and only single-layer shotcrete bolting support is needed for the out-of-vein section; during ventilation, fresh air flows into the ore room from the stoping drift to wash the working face, and the dirty air in the ore room is extracted by the cross-cut filling return airway 4 at the top of the ore room and discharged to the sublevel footwall cross-heading 11 connected to it, and then discharged into the return air shaft. At the same time, a filling pipeline 9 is arranged in this roadway. The filling pipeline 9 is lowered from the surface to the stope through the filling pipeline shaft 10 to achieve high-level filling of the ore room; When each sublevel is mined, in order to prevent the roof exposure area from being too large, the drifts in the sublevel need to be numbered in sequence. The odd-numbered drifts are used as the first-step stope 15, and the even-numbered drifts are used as the second-step stope 16. The first-step stope 15 and the second-step stope 16 are mined alternately. The first-step stope 15 is at least one ore room ahead of the second-step stope 16, and adjacent drifts cannot be mined simultaneously in the transverse direction; The stoping drifts in each sublevel are supported by single-layer shotcrete bolting. Operations such as ore drawing, drilling, charging, ventilation, and ore extraction are all completed in the drift; before the drift is mined, an upward spindle-shaped blast row 6 is arranged in the drift. The diameter of the blast hole is 80 mm, and the angle of the side hole of the blast row should be greater than the natural angle of repose of the caved ore 22 under the open stope. Preferably, the side hole is taken as 55°, so as to ensure that the caved ore can roll down from the side walls of the ore room to the floor of the drift under the action of its own weight and be centrally shoveled out. The blast hole spacing is taken as 3 m, which can increase the amount of ore caved at one time and protect the brow line of the rear row of holes. Since the blast row for ore caving is spindle-shaped, the formed ore room is also spindle-shaped; Before mining is withdrawn, a cutting groove is constructed at the end of the upper plate of each access road as the blasting compensation space for the initial mining of the access road. During mining, the ore is withdrawn row by row from the upper plate to the lower plate. The collapsed ore 22 is shoveled out of the mine room by a remote-controlled scraper. In order to improve the mining efficiency, the ore is transported to the ore chute 12 in the mining field by manual driving outside the mine room, and finally lowered to the stage transportation tunnel 13 through the ore chute in the mining field for centralized transportation. Usually, the mine room can be filled once every 15 to 30 meters of mining withdrawal to prevent the exposed area of ​​the mine room from being too large and causing a decrease in stability. The preferred length of the first mining section mine room is 15 meters. The length of the remaining segmented mine rooms can be increased to 30m; before filling, a filling retaining wall 8 is built at the connection point between the mining access road and the filling return air tunnel and the mine room to seal the mine room. The filling of the mine room is completed in two times. First, a filling material with a 28d compressive strength of 5MPa is used to fill the lower half of the mine room (the filling material is a slurry made by mixing water, cement and tailings in proportion, and the proportion is to meet the "28d compressive strength of 5MPa", which is a conventional technology in this field). After the lower half solidifies for 3d, a filling material with a 28d compressive strength of 2MPa is used to fill the upper half of the mine room, thereby reducing the filling cost. Since the filling tunnel is located at the top of the mine room, the filling material fills the mine room from top to bottom. In addition, the upper part of the spindle-shaped mine room presents an inverted "V" structure, and the space gradually shrinks. Therefore, this method can ensure that the mine room can be basically backfilled. The mine room backfill rate (the ratio of the volume of the unfilled empty area in the mine room to the total volume of the mine room) can reach more than 98%, while the conventional backfill rate is generally around 90%.

[0020] During the mining withdrawal process, after the cemented filling body of the previous chamber reaches the designed strength, a cutting chamber 7 with a diameter of 1.0 m is constructed on the top plate of the mining access road by using a raise drill immediately behind the filling body, and spindle-shaped blastholes are arranged around the cutting chamber 7. The cutting chamber 7 is used as a blasting compensation space, and the blasting operation of the first row of blastholes in the next chamber is completed (which can also be regarded as forming an upper plate cutting groove 14), providing a blasting compensation space for subsequent blasthole rows, and then retreating the mining row by row to form a new spindle-shaped chamber and complete the filling work, and the cycle is repeated until the mining withdrawal of one chamber is completed; During the mining process of each approach, after each row of spindle-shaped blastholes is blasted, fresh air is transported to the mine room through the compressed air local fans in the mining approach, and the polluted air in the mine room is extracted by the exhaust local fans in the vein-filling return air tunnel on the top of the mine room, and discharged to the segmented lower wall connecting tunnel 11 outside the vein, and finally discharged to the return air shaft. In this method, the mining field has good ventilation conditions.

[0021] This method is to mine downward in sections. Only after the adjacent access of the previous section has been mined and a false roof of the filling body has been formed, can the corresponding access of the next section be mined, thereby ensuring that the roof of the next section's spindle-shaped mine room is the cemented filling body 19 of the previous section, thereby achieving the stability of the mine room roof. In this method, for any mine room, its roof is the cemented filling body 19, and only the two inclined walls at the bottom of the mine room are the ore body 18, but the angles of these two inclined walls are usually 50~60°, and the stability is better. In addition, except for the first mining section mine room which is semi-spindle-shaped, the remaining section mine rooms are all spindle-shaped, which is more conducive to the distribution of ground pressure, so the entire mine room has better stability; It should be noted that Figure 1-Figure 3 In the figure, different filling figures represent different entities, for example, the lower right oblique line is filled with surrounding rock 17, the lower left oblique line is filled with ore body 18, the finer particles are filled with cemented filling body 21, and the coarser particles are filled with collapsed rock 20.

[0022] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A downward segmented spindle-shaped empty field followed by cementation and filling mining method, characterized in that: It includes the following steps: (1) First, at least three slices are mined by the downward slicing drift cemented filling method at the top position of the ore body to form an initial false roof for the entire stope; (2) Below the initial false roof, mining is carried out by the downward sublevel spindle-shaped open stoping followed by cemented filling. During stoping, mining is carried out from top to bottom slice by slice. The stoping drifts between the upper and lower adjacent slices are arranged in a "pin" shape in stagger. Except for the ore room formed by the stoping of the first mined slice drift, which is semi-"spindle-shaped", the shapes of the ore rooms formed by the stoping of the drifts in the other slices are all "spindle-shaped"; (3) Upward spindle-shaped blast rows are arranged in the drifts of each slice. The blast row in the first mined slice is semi-spindle-shaped. Using the upward blast rows, ore caving and retreating mining are carried out row by row from the hanging wall to the footwall to form a spindle-shaped ore room with the same shape as the blast row. The ore room is filled in two times with cemented materials of different strengths for the upper half and the lower half respectively; (4) After the cemented filling body of the previous ore room is stable, a cut raise is constructed upward adjacent to the filling body in the stoping drift. Using this raise as the blasting compensation space, the initial slotting operation of the subsequent ore room is completed. Subsequently, ore caving and retreating are carried out row by row to form a new spindle-shaped ore room and then filled. This process is repeated until the complete retreating mining of one drift is finished.

2. A downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1, characterized in that: In step (2), the sublevel height and the drift spacing are both 15 - 20 m.

3. A downward segmented spindle-shaped empty site followed by cementation and filling mining method according to claim 1, characterized in that: In step (2), a cross-cut filling return airway is arranged at the top of the ore room.

4. A downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1, characterized in that: In step (3), the blast row spacing is 2 - 4 m.

5. The downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1 is characterized in that: In step (3), the lower half of the ore room is filled with a cemented material with a compressive strength of 3 - 5 MPa. After the lower half filling body solidifies, the upper half is filled, and the upper half is filled with a cemented material with a compressive strength of 1 - 2 MPa.

6. A downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1, characterized in that: In step (3), the ore room is filled once every 10 - 30 m of retreating mining.

7. A downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1, characterized in that: In step (3), the length of the ore room in the first mined slice is 10 - 15 m, and the length of the ore rooms in the other slices can be increased to 20 - 30 m.

8. The downward segmented spindle-shaped open-pit subsequent cementation filling mining method according to claim 1 is characterized in that: In step (3), multiple drifts in the same slice are operated simultaneously. To control the exposed area of the roof, the adjacent drifts in the slice are divided into a first-step stope and a second-step stope for alternating mining. The first-step stope is at least one ore room ahead of the second-step stope, and adjacent drifts cannot be mined simultaneously in the transverse direction.

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