A panel pillar mining method

Abstract

The present application provides a panel pillar mining method, which relates to the field of mining; the panel pillar mining method includes: dividing the panel pillar into several sub-areas along the length direction of the panel pillar, and dividing the panel pillar into several sections along the height direction of the panel pillar, constructing at least one section of roadway in each section; leaving a trench at the bottom of the lowest section, connecting the trench with the section roadway of the lowest section; constructing a first blast hole at the goaf position in each section by using the section roadway, and mining out the goaf by the open stoping method; after the goaf is formed, using the goaf as a free surface and compensation space, constructing a second blast hole and a third blast hole in the remaining ore body in the corresponding section; the blasted ore falls into the trench, and the ore is concentrated and discharged through the section roadway of the lowest section. The present application adopts a combination of the open stoping method and the caving method. During the open stoping method mining, the mixing of waste rock and ore fragments is avoided, the recovery rate is increased, and the dilution rate is reduced. During the caving method mining, the safety of blasting personnel is protected.

Description

Technical Field

[0001] This application relates to the field of mining, and more particularly, to a method for mining panel pillars. Background Art

[0002] After the panel mining is completed, the panel pillars need to be mined by blasting. Currently, the sublevel caving method without sill pillars is mainly used for mining. Specifically, first, the panel pillars are divided into sublevels in the height direction, sublevel headings are constructed within the sublevels, fan-shaped blast holes are drilled upward through the sublevel headings, and when the blast holes are detonated, the blasting is carried out row by row from the inside to the outside within the sublevel. Between the sublevels, the upper sublevel blasts ahead of the lower sublevel. Finally, the blasted ore falls to the lower ore drawing level, and a load-haul-dump (LHD) machine is used for centralized ore drawing at the ore drawing level.

[0003] When using the sublevel caving method without sill pillars to mine panel pillars, since the blast holes are detonated row by row, after each row of blast holes is detonated, the panel pillars are broken into ore fragments and fall, and the vacated space is directly occupied by nearby waste rocks. The waste rocks are mixed with the ore fragments, resulting in ore loss and a very high dilution rate. Summary of the Invention

[0004] The purpose of this application is to provide a method for mining panel pillars, which uses a combination of the open stoping method and the caving method for mining. During the open stoping method mining process, the mixing of waste rocks and ore fragments can be avoided, the recovery rate can be increased, and the dilution rate can be reduced.

[0005] This application provides a method for mining panel pillars, which includes:

[0006] The panel pillar is divided into several partitions along the length direction of the panel pillar, and the panel pillar is divided into several sublevels along the height direction of the panel pillar. At least one sublevel heading is constructed within each sublevel;

[0007] A trench is left at the bottom of the lowest sublevel, and the trench is connected to the sublevel heading of the lowest sublevel;

[0008] In each sublevel, the first blast holes are drilled at the goaf position by using the sublevel heading, and the goaf is mined by the open stoping method;

[0009] After the goaf is formed, taking the goaf as the free face and compensation space, the second blast holes and the third blast holes are drilled in the remaining ore body within the corresponding sublevel, and overall blasting is carried out by the caving method;

[0010] The blasted ore falls into the trench, and centralized ore drawing is carried out through the sublevel heading of the lowest sublevel.

[0011] Further, one end of the sectional roadway located within the panel pillar is defined as the first end, and the end separated from the panel pillar is defined as the second end. The extraction of the panel pillar is carried out by sectional extraction in sequence from the first end to the second end.

[0012] Further, the panel pillar extraction method further includes: driving a crosscut along the vein in each section and connecting the crosscut along the vein with the sectional roadway in the corresponding section.

[0013] Further, the third blast hole is inclinedly constructed.

[0014] Further, the method of extracting the goaf by the open stoping method includes: driving a cutting crossheading at the end of the goaf area, then driving a cutting raise upward at one end of the cutting crossheading, constructing a fourth blast hole in the cutting crossheading with the cutting raise as a compensation space, blasting to form a cutting slot, then constructing the first blast hole in the sectional roadway, and then retreating and mining row by row with the cutting slot as a compensation space.

[0015] Further, the diameter of the cutting raise is 0.5 - 1.5 m.

[0016] Further, the length of each section is 20 - 40 m.

[0017] Further, the height of each section is 10 - 20 m.

[0018] Further, the boundary of the goaf is 5 - 15 m away from the sectional boundary, and the volume of the ore body in the goaf is defined as V1, and the volume of the remaining ore body in the corresponding section is defined as V2, and V1 / V2 ≥ 20%.

[0019] Further, the exposed area of the roof and side wall of the goaf is less than the allowable exposed area in the corresponding section.

[0020] Compared with the prior art, the beneficial effects of the present application are as follows:

[0021] In the present application, by partitioning and sectionally extracting the panel pillar, first using the open stoping method to extract the goaf, and then using the goaf as a compensation space to integrally caving the remaining ore body by the caving method, the safety during the extraction process is significantly improved, the extraction cycle is shortened, the mining duration of miners in the sectional roadway is reduced, the mining risk is reduced, and the present application combines the open stoping method and the caving method. During the open stoping method mining, the mixing of waste rock and ore fragments is avoided, the recovery rate is increased, and the dilution rate is reduced. During the caving method mining, the personal safety of blasting personnel is protected. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for the embodiments will be briefly introduced below. It should be understood that the following accompanying drawings only show some embodiments of the present invention, and therefore should not be regarded as a limitation of the scope. For those of ordinary skill in the art, without creative efforts, other related accompanying drawings can also be obtained based on these drawings.

[0023] Figure 1 Shows the construction schematic diagram of the panel pillar in the width direction in some embodiments;

[0024] Figure 2 Shows in some embodiments Figure 1 The schematic diagram of the II-II section in;

[0025] Figure 3 Shows in some embodiments Figure 1 The schematic diagram of the III-III section in;

[0026] Figure 4 Shows in some embodiments Figure 1 The schematic diagram of the IV-IV section in;

[0027] Figure 5 Shows another construction schematic diagram of the panel pillar in the width direction in some embodiments.

[0028] Main element symbol description:

[0029] 100 - Panel pillar; 110 - First partition; 120 - Second partition; 101 - Uppermost segment; 102 - Intermediate segment; 103 - Lowermost segment; 1001 - Segment roadway; 1002 - Trench; 1003 - First blast hole; 1004 - Second blast hole; 1005 - Third blast hole; 1006 - Goaf; 1007 - Cutting crossheading; 1008 - Cutting raise; 1009 - Crosscut; 1010 - Shaft; 200 - Waste rock. Detailed implementation manners

[0030] The embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the accompanying drawings, where the same or similar reference numerals represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application and should not be construed as a limitation of the present application.

[0031] In the description of the present application, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationships shown in the drawings. These are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application.

[0032] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0033] In the present application, unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0034] In the present application, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0035] Embodiment

[0036] Please refer to Figure 1 and Figure 2, during the panel mining process, the panel pillar 100 serves as a support structure between two adjacent panels to ensure the safety of mining. That is, the panel pillar 100 itself is an ore body with high economic value. After the panel mining is completed, the panel pillar 100 needs to be recovered and utilized. At this time, except for the panel pillar 100 in the panel, the surrounding areas are all waste rocks 200, and the stability of the waste rocks 200 is extremely poor. Slight blasting vibration is sufficient to destroy the stability of the waste rocks 200, resulting in the rolling of the waste rocks 200.

[0037] On the one hand, during the recovery process of the panel pillar 100, the personal safety of miners is threatened to a certain extent. On the other hand, the waste rocks 200 are mixed with broken ore fragments, resulting in ore loss and a high dilution rate.

[0038] This embodiment provides a method for recovering panel pillars. The method for recovering panel pillars includes the following steps:

[0039] S100. Divide the panel pillar 100 into several sections along the length direction of the panel pillar 100, and divide the panel pillar 100 into several segments along the height direction of the panel pillar 100. At least one section of roadway 1001 is constructed within each segment.

[0040] For the convenience of description and understanding, this embodiment will be exemplarily described with two sections and three segments.

[0041] Define the two sections as the first section 110 and the second section 120 respectively. Among them, along the length direction of the panel pillar 100, the first section 110 is relatively closer to the waste rocks 200 than the second section 120. It can be understood that the width of each section is the width of the panel pillar 100.

[0042] Define the three segments as the uppermost segment 101, the middle segment 102, and the lowermost segment 103 respectively. Among them, the uppermost segment 101 is relatively closer to the waste rocks 200 than the middle segment 102.

[0043] In some embodiments, the length of each section is 20 - 40m. Miners can make a reasonable division according to the actual length of the panel pillar 100. For example, divide the panel pillar 100 with a length of 50m into two equal-length sections, and the length of each section is 25m.

[0044] Of course, for the convenience of division, the lengths of each section can also be unequal. For example, divide the panel pillar 100 with a length of 55m into two sections. The length of the first section 110 is 25 meters, and the length of the second section 120 is 30m.

[0045] In some embodiments, the height of each segment is 10 - 20m. Similar to the length of the partition, miners can rationally divide according to the actual height of the panel pillar 100. For example, the panel pillar 100 with a height of 45m is evenly divided into three segments of equal height, and the height of each segment is 15m.

[0046] As described above, the length range of each partition and the height range of each segment are obtained through continuous experiments by the inventor. Under the premise of ensuring safety, the blasting effect is good. It can be understood that if the maximization of blasting efficiency is not pursued, the values outside the above ranges can also be used for the partition and segment values.

[0047] In this embodiment, one end of the sectional roadway 1001 located within the panel pillar 100 is defined as the first end, and the end separated from the panel pillar 100 is defined as the second end. The mining of the panel pillar 100 is carried out by partition mining in sequence from the first end to the second end.

[0048] Specifically, when miners carry out the mining of the panel pillar 100, they first mine the segment closest to the waste rock 200 (i.e., the first partition 110), and gradually retreat to the roadway opening of the sectional roadway 1001. Such a retreating mining method can ensure the personal safety of miners to the greatest extent and improve the mining efficiency.

[0049] There are three segments in total for the segment closest to the waste rock 200. Miners can carry out overall blasting on the uppermost segment 101, the middle segment 102, and the lowermost segment 103 by the full caving method.

[0050] In summary, the sectional roadway 1001 has functions such as passage, charging, and transportation.

[0051] This embodiment significantly improves the safety during the mining process, shortens the mining cycle, reduces the mining duration of miners in the sectional roadway 1001, and reduces the mining risk by partitioning and segmenting the mining of the panel pillar 100.

[0052] S200. Leave a trench 1002 at the bottom of the lowermost segment, and connect the trench 1002 with the sectional roadway 1001 of the lowermost segment 103.

[0053] The trench 1002 is configured to be two opposite ones, and the two trenches 1002 are arranged at an angle. And the lowest part of each trench 1002 is connected to the sectional roadway 1001 of the lowermost segment 103, and the sectional roadway 1001 serves as a collecting roadway.

[0054] S300. In each partition, use the sectional roadway 1001 to construct the first blast hole 1003 at the goaf 1006 position, and extract the goaf 1006 by the open stoping method.

[0055] Please refer to Figure 3And Figure 4 For the open stoping method to extract the goaf 1006, it includes: constructing a cutting crossheading 1007 at the end of the goaf 1006 area, then constructing a cutting raise 1008 upward from one end of the cutting crossheading 1007, constructing the fourth blast hole in the cutting crossheading 1007 with the cutting raise 1008 as the compensation space, blasting to form a cutting slot, then constructing the first blast hole 1003 in the sectional roadway 1001, and then retreating in rows for mining with the cutting slot as the compensation space, blasting 2 - 4 rows each time.

[0056] In this embodiment, it can also be set that the width of the cutting slot is configured to be 2 - 5 m, and the length of the cutting slot is the same as the width of the goaf 1006, and the height of the cutting slot is the same as the height of the goaf 1006.

[0057] When conducting open stoping blast holes in multiple levels, the method of the upper level leading the lower level or blasting multiple levels simultaneously can be adopted.

[0058] In some embodiments, the diameter of the cutting raise 1008 is 0.5 - 1.5 m.

[0059] In some embodiments, the boundary of the goaf 1006 is 5 - 15 m away from the sectional boundary, and the boundary between the goaf 1006 and the sectional boundary is defined as D.

[0060] Define the ore body volume of the goaf 1006 as V1, and the remaining ore body volume in the corresponding section as V2, and V1 / V2 ≥ 20%.

[0061] In some embodiments, the exposed area of the roof and side walls of the goaf 1006 is less than the allowable exposed area in the corresponding section.

[0062] In this embodiment, the goaf 1006 is extracted by the open stoping method. At this time, the blasted ore fragments are protected by the surrounding remaining ore body and will not come into contact with the waste rock 200 outside the remaining ore body, let alone be mixed with the waste rock 200. Therefore, the blasted ore fragments in the goaf 1006 have good recovery significance, with high recovery rate and low dilution rate.

[0063] Please refer to Figure 5 .

[0064] S400. After the goaf 1006 is formed, using the goaf 1006 as the free face and compensation space, construct the second blast hole 1004 and the third blast hole 1005 in the remaining ore body in the corresponding section, and conduct overall blasting by the caving method.

[0065] In this embodiment, the second blast hole 1004 and the third blast hole 1005 are blasted simultaneously by the overall caving method. After charging, the blasters withdraw, effectively ensuring personal safety and reducing the probability of accidents.

[0066] Specifically, after the gob areas 1006 in the middle section 102 and the bottommost section 103 are formed, second blast holes 1004 are constructed on both sides of the gob area 1006 and charged and blasted. At this time, the sectional roadways 1001 on both sides of the gob area 1006 remain intact and can be used as the standing positions for miners to charge.

[0067] The third blast holes 1005 are constructed obliquely.

[0068] In this embodiment, the section is divided into three sections. Gob areas 1006 are respectively mined out in the middle section 102 and the bottommost section 103. Then, third blast holes 1005 are constructed in the uppermost section 101. A plurality of third blast holes 1005 are arranged in a fan shape. Miners stand in the sectional roadway 1001 of the uppermost section 101 to charge.

[0069] During the construction of the fan-shaped third blast holes 1005 as described above, due to the formation of the gob area 1006 in the middle section 102, the position corresponding to the gob area 1006 in the sectional roadway 1001 of the uppermost section 101 has collapsed. At this time, there are two standing positions for miners in the sectional roadway 1001 of the uppermost section 101. The first position is on the left side of the gob area 1006, and the second position is on the right side of the gob area 1006.

[0070] At the first position, miners arrange a set of fan-shaped third blast holes 1005 upward. At the second position, miners also arrange a set of fan-shaped third blast holes 1005 upward. The two sets of third blast holes 1005 are arranged oppositely. After blasting, a space corresponding to the gob area 1006 can be formed. The overlying waste rock 200 immediately falls and occupies this space. At this time, the waste rock 200 is located above the ore fragments, and the situation of mixing will not occur, improving the dilution rate.

[0071] Since the diameter of the blast holes is much smaller than the size of the panel pillar 100, the first blast hole 1003, the second blast hole 1004, and the third blast hole 1005 are presented in a straight line in the figure.

[0072] Please refer to Figure 1 for reference.

[0073] S500. The blasted ore falls to the trench 1002 and is centrally ore-drawn through the sectional roadway 1001 of the bottommost section 103.

[0074] Please refer to Figure 3 for reference.

[0075] S600. A crosscut 1009 is constructed in each section, and the crosscut 1009 is connected to the sectional roadway 1001 in the corresponding section.

[0076] The crosscut 1009 serves as a transportation roadway.

[0077] A ore pass 1010 is set on the drift along the vein. After blasting, the ore fragments are transported out by a load-haul-dump (LHD) vehicle, transported from the sublevel drift 1001 to the drift along the vein 1009, and then poured into the ore pass 1010 nearby for transportation.

[0078] In this embodiment, the open stoping method and the caving method are combined. During the open stoping method, the mixing of waste rock 200 and ore fragments is avoided, the recovery rate is increased, and the dilution rate is reduced. During the caving method, the personal safety of blasting personnel is protected.

[0079] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0080] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A panel pillar mining method, characterized in that, Including: The panel pillar is divided into several sub - areas along the length direction of the panel pillar, and is divided into several segments along the height direction of the panel pillar. The number of segments is three, and the three segments are respectively defined as the uppermost segment, the middle segment and the lowermost segment. Among them, the uppermost segment is closer to the waste rock relative to the middle segment. At least one segment roadway is constructed within each segment; A cut - off trench is left at the bottom of the lowermost segment, and the cut - off trench is communicated with the segment roadway in the lowermost segment; In the middle segment and the lowermost segment, the first blast holes are constructed at the goaf position by using the segment roadway, and the goaf is mined out by the open - stoping method; After the goaf is formed, taking the goaf as the free face and compensation space, the second blast holes are constructed on both sides of the goaf in the middle segment and the lowermost segment, and the third blast holes are constructed in the uppermost segment, and overall blasting is carried out by the caving method; The blasted ore falls into the cut - off trench, and is concentrated for ore drawing through the segment roadway in the lowermost segment.

2. The panel pillar mining method according to claim 1, wherein, One end of the segment roadway located within the panel pillar is defined as the first end, and the end separated from the panel pillar is defined as the second end. The stoping of the panel pillar is carried out in sequence by segment stoping from the first end to the second end.

3. The panel pillar mining method according to claim 2, characterized in that, Also including: A drift along the vein is constructed within each segment, and the drift along the vein is communicated with the segment roadway in the corresponding segment.

4. The panel pillar mining method according to any one of claims 1 to 3, characterized in that, The third blast holes are constructed obliquely.

5. The panel pillar mining method according to any one of claims 1 to 3, characterized in that, Mining out the goaf by the open - stoping method includes: constructing a cut - off cross - drift at the end of the goaf area, then constructing a cut - off raise upward at one end of the cut - off cross - drift, constructing the fourth blast holes in the cut - off cross - drift with the cut - off raise as the compensation space, blasting to form a cut - off slot, then constructing the first blast holes in the segment roadway, and then retreating for stoping row by row with the cut - off slot as the compensation space.

6. The panel pillar mining method according to claim 5, characterized in that, The diameter of the cut - off raise is 0.5 - 1.5m.

7. The panel pillar mining method according to any one of claims 1 to 3, characterized in that, The length of each sub - area is 20 - 40m.

8. The panel pillar mining method according to any one of claims 1 to 3, characterized in that, The height of each segment is 10 - 20m.

9. The panel pillar mining method according to any one of claims 1 to 3, characterized in that, The boundary of the goaf is 5 - 15m away from the segment boundary, and the volume of the ore body in the goaf is defined as V1, and the volume of the remaining ore body in the corresponding segment is defined as V2, and V1 / V2≥20%.

10. The panel pillar mining method according to claim 9, characterized in that, The exposed area of the roof and side wall of the goaf is less than the allowable exposed area in the corresponding segment.

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