A Blasthole Construction Method at the Junction of Stope and Pillar

Abstract

The present invention relates to a method for constructing blastholes at the junction of a mine room and a pillar, and relates to the field of blasting recovery. The construction method comprises the following steps: recovering the pillars; installing prefabricated blastholes on the junction surface between the pillar goaf and the mine room; filling the pillar goaf with a filling body; charging the prefabricated blastholes, and carrying out blasting. The beneficial effects of the present invention are as follows: the blasthole construction method uses prefabricated blastholes to achieve precise control of the boundaries of the ore body. The difficulty of blasthole construction at the junction of the mine room and the pillars is significantly reduced, the construction accuracy is significantly improved, the depletion rate is reduced by more than 30%, and the loss rate is reduced by more than 50%.

Description

Technical Field

[0001] The present invention relates to the field of blasting stoping in mines using the stage open stoping with subsequent backfilling mining method, especially the stope stoping in metallurgical and non-ferrous mines with high ore value and relatively broken ore bodies. Specifically, the present invention relates to a method for constructing blast holes at the junction of ore rooms and ore pillars. Background Art

[0002] In mines using the stage open stoping with subsequent backfilling mining method, mining is mainly divided into two steps. The mining sequence is as follows: first, the ore pillars are mined and cemented backfilled, and then the ore rooms are mined. Due to the irregularity of the joint surface between the ore room and the ore pillar and the broken rock, the ore recovery efficiency at the junction of the ore room and the ore pillar is seriously affected, and the ore loss and dilution rates have always been high.

[0003] To solve this problem, the existing technology adopts the following method: after the ore pillar mining is completed, a 3D scanner is used to scan the mined-out area of the ore pillar to determine the shape of the joint surface between the ore pillar and the ore room; after the cemented backfilling of the ore pillar is completed, according to the shape of the joint surface, blast holes are arranged and drilled in the upper part for blasting stoping.

[0004] The existing technology has the following disadvantages: 1. On one side of the junction of the ore room and the ore pillar is the backfill body, and on the other side is the original ore rock of the ore body. The deviation rate of drilling blast holes is large, and the hole wall is broken, making it extremely easy to block the holes; 2. The joint surface between the ore room and the ore pillar is not regular, and it is impossible to avoid drilling into the backfill body or missing a part of the ore body when arranging blast holes. Summary of the Invention

[0005] The technical problem to be solved by the present invention is how to improve the ore recovery efficiency at the junction of the ore room and the ore pillar.

[0006] The technical solution of the present invention to solve the above technical problem is as follows: A method for constructing blast holes at the junction of ore rooms and ore pillars, comprising the following steps:

[0007] Step 1: Mining of ore pillars;

[0008] Step 2: Installing prefabricated blast holes on the joint surface between the mined-out area of the ore pillar and the ore room;

[0009] Step 3: Backfilling the mined-out area of the ore pillar with backfill body;

[0010] Step 4: Charging the prefabricated blast holes and implementing blasting.

[0011] The beneficial effect of the present invention is that: This method for constructing blast holes uses prefabricated blast holes, achieving precise control of the ore body boundary. The construction difficulty of blast holes at the junction of the ore room and the ore pillar is significantly reduced, the construction accuracy is significantly improved, the dilution rate is reduced by more than 30%, and the loss rate is reduced by more than 50%.

[0012] On the basis of the above technical solutions, the present invention can also be improved as follows.

[0013] Further, in step 2, the prefabricated blast holes are inclined tubular structures, and there are multiple of them. The multiple prefabricated blast holes are parallel to each other and evenly distributed, and the inclination angle of the prefabricated blast holes is the same as the inclination angle of the ore body.

[0014] The beneficial effect of adopting the above further solution is that the inclination angle of the prefabricated blast holes is the same as that of the ore body, which can reduce the blast hole density coefficient, increase the ore production per meter of blast hole and reduce the unit explosive consumption. The ore production per meter of blast hole is also called the blasting volume per meter.

[0015] Further, in step 2, the upper end of the prefabricated blast hole is detachably connected to the roadway roof through a ground anchor bolt, and the lower end of the prefabricated blast hole is detachably connected to a filling retaining wall in the roadway floor.

[0016] The beneficial effect of adopting the above further solution is that the prefabricated blast holes are convenient to fix, and the ground anchor bolts can be recycled and reused.

[0017] Further, step 4 specifically includes: removing the ground anchor bolts, plugging the prefabricated blast holes to meet the charging conditions, charging the prefabricated blast holes, and implementing blasting.

[0018] The beneficial effect of adopting the above further solution is that the ground anchor bolts are removed and recycled, reducing material waste.

[0019] Further, between step 3 and step 4, it also includes: cutting off the part of the prefabricated blast hole extending out of the ore body and the filling body.

[0020] The beneficial effect of adopting the above further solution is that by cutting off the upper end of the prefabricated blast hole, the connection between the prefabricated blast hole and the ground anchor bolt can be quickly released, and the ground anchor bolt can be quickly removed and recycled.

[0021] The present invention also provides a blast hole installation structure at the joint of a stope and a pillar, including prefabricated blast holes. The prefabricated blast holes are installed at the joint surface between the goaf of the pillar and the stope. The goaf of the pillar is filled with a filling body, and the prefabricated blast holes are filled with explosives.

[0022] The beneficial effect of adopting the above further solution is that the blast hole installation structure has a simple structure, low cost, simple process and convenient installation. It realizes precise control of the ore body boundary. The construction difficulty of the blast holes at the joint of the stope and the pillar is significantly reduced, the construction accuracy is significantly improved, the dilution rate is reduced by more than 30%, and the loss rate is reduced by more than 50%.

[0023] Further, the prefabricated blast holes are tubular structures arranged obliquely, and there are multiple of them. The multiple prefabricated blast holes are parallel to each other and evenly distributed, and the inclination angle of the prefabricated blast holes is the same as the inclination angle of the ore body.

[0024] The beneficial effect of adopting the above further scheme is that the prefabricated blast holes are parallel to the inclination angle of the ore body and evenly distributed, reducing the blast hole density coefficient, increasing the ore fragmentation per meter of blast hole and reducing the unit consumption of explosive. The ore fragmentation per meter of blast hole is also called the blasting volume per meter.

[0025] Further, it also includes ground anchor bolts. The lower end of the ground anchor bolts can be detachably inserted into the bottom plate of the drilling chamber above the roof of the roadway. The upper end of the prefabricated blast holes extends into the drilling chamber, and the upper end of the ground anchor bolts is detachably connected to the upper end of the prefabricated blast holes.

[0026] The beneficial effect of adopting the above further scheme is that the prefabricated blast holes are convenient to fix, and the ground anchor bolts can be recycled and reused.

[0027] Further, the ground anchor bolts are arranged vertically, and the horizontal distance from the ground anchor bolts to the joint surface of the pillar goaf and the stope is greater than or equal to 1 m. The depth of the lower end of the ground anchor bolts inserted into the bottom plate of the drilling chamber is greater than or equal to 0.6 m, and the length of the upper end of the ground anchor bolts protruding from the bottom plate of the drilling chamber is greater than or equal to 1 m.

[0028] The beneficial effect of adopting the above further scheme is that the structure of the ground anchor bolts is stable and the reliability is high.

[0029] Further, it also includes a filling retaining wall. The filling retaining wall is vertically fixed in the bottom plate of the roadway, and the lower end of the prefabricated blast holes is detachably connected to the filling retaining wall.

[0030] The beneficial effect of adopting the above further scheme is that when filling the pillar goaf, the filling retaining wall serves as the boundary of the filling body to limit the range of the filling body. At the same time, the filling body is used to fix the prefabricated blast holes without adding too many additional structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic diagram of the layout of the prefabricated blast holes of the blast hole installation structure at the joint of the stope and the pillar of the present invention;

[0032] Figure 2 is Figure 1 a side view of the schematic diagram of the layout of the prefabricated blast holes;

[0033] Figure 3 is Figure 2 a partial enlarged view at the ground anchor bolts; the dimensions shown in the figure are only one preferred embodiment.

[0034] In the drawings, the list of components represented by each reference numeral is as follows:

[0035] 1. Drifting chamber for rock drilling; 2. Ground anchor bolt; 3. Prefabricated blast hole; 4. Ore body boundary; 5. Filling retaining wall; 6. Pillar goaf; 7. Blast holes drilled in the stope; 8. Stope; 9. Undercutting roadway. Specific implementation mode

[0036] The principles and features of the present invention will be described below. The examples given are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0037] As Figures 1-3 shown, a blast hole construction method at the joint of a stope and a pillar in this embodiment includes the following steps:

[0038] Step 1: Pillar extraction

[0039] Step 2: Install the prefabricated blast hole 3 on the joint surface between the pillar goaf 6 and the stope 8.

[0040] Step 3: Fill the pillar goaf 6 with filling material.

[0041] Step 4: Charge the prefabricated blast hole 3 and carry out blasting.

[0042] This blast hole construction method uses the prefabricated blast hole 3, realizing precise control of the ore body boundary. It significantly reduces the construction difficulty of the blast holes at the joint of the stope and the pillar, significantly improves the construction accuracy, reduces the dilution rate by more than 30%, and reduces the loss rate by more than 50%.

[0043] Specifically, in step 4, the upper end of the prefabricated blast hole 3 extends into the drifting chamber 1 above the roadway, and charging is carried out from the upper end of the prefabricated blast hole 3.

[0044] On the basis of the above solution, in step 2, the prefabricated blast hole 3 is an inclined tubular structure, and there are multiple of them. The multiple prefabricated blast holes 3 are parallel to each other and evenly distributed, and the inclination angle of the prefabricated blast hole 3 is the same as the inclination angle of the ore body.

[0045] The inclination angle of the prefabricated blast hole 3 being the same as the inclination angle of the ore body can reduce the blast hole density coefficient, increase the ore broken per meter of blast hole, and reduce the unit consumption of explosive. The ore broken per meter of blast hole is also called the blasting volume per meter.

[0046] On the basis of the above solution, in step 2, the upper end of the prefabricated blast hole 3 is detachably connected to the roadway roof through the ground anchor bolt 2, and the lower end of the prefabricated blast hole 3 is detachably connected to the filling retaining wall 5 in the roadway floor.

[0047] The prefabricated blast hole 3 is convenient to fix, and the ground anchor bolt 2 can be recycled and reused.

[0048] On the basis of the above solution, step 4 specifically includes: removing the ground anchor bolt 2, plugging the prefabricated blast hole 3 to meet the charging condition, charging the prefabricated blast hole 3, and implementing blasting.

[0049] Remove and recycle the ground anchor bolt 2 to reduce material waste.

[0050] Specifically, plugging the prefabricated blast hole 3 is specifically as follows: insert the plugging material from the upper end of the prefabricated blast hole 3, and plug the lower end of the prefabricated blast hole 3 through the plugging material. The plugging material can be common plugging materials for blast holes such as stemming. Charge in the middle section of the prefabricated blast hole 3. After charging, the upper end of the prefabricated blast hole 3 can also be plugged through the plugging material to ensure the blasting effect.

[0051] On the basis of the above solution, between step 3 and step 4, it also includes: cutting off the part of the prefabricated blast hole 3 that extends out of the ore body and the filling body.

[0052] The upper end of the prefabricated blast hole 3 extends out of the ore body and the filling body, which is convenient for fixing with the ground anchor bolt 2. Cutting off the upper end of the prefabricated blast hole 3 before blasting can quickly release the connection between the prefabricated blast hole 3 and the ground anchor bolt 2, and quickly remove and recycle the ground anchor bolt 2.

[0053] In one specific embodiment, a blast hole construction method at the joint of the ore room and the ore pillar includes the following working steps:

[0054] Ore pillar extraction;

[0055] Clean the roof and floor of the roadway;

[0056] Construct the upper ground anchor bolt 2;

[0057] Construct the filling retaining wall 5;

[0058] Install the prefabricated blast hole 3 and fix it firmly. Specifically, the upper end of the prefabricated blast hole 3 is fixed with the ground anchor bolt 2, and the lower end of the prefabricated blast hole 3 is fixed with the filling retaining wall 5;

[0059] Cementitious filling of the mined - out area 6 of the ore pillar;

[0060] Cut off the upper and lower parts of the prefabricated blast hole 3 that exceed the ore body and the filling body, release the fixing structure of the prefabricated blast hole 3 and recycle the relevant materials. Specifically, remove the ground anchor bolt 2 and recycle it;

[0061] Plug the prefabricated blast hole 3 to meet the charging requirements. After detecting and plugging the prefabricated blast hole 3, it is ready for charging and blasting;

[0062] Charge the prefabricated blast hole 3 and implement blasting.

[0063] Specifically, as Figure 2As shown in the figure, during the extraction of the stope, the existing construction plan is adopted. Specifically, blast holes 7 are drilled in the ore body as the blast holes during normal extraction, and explosives are charged into the blast holes 7 drilled in the stope and blasting is carried out.

[0064] This embodiment also provides a blast hole installation structure at the junction of the stope and the pillar, including a prefabricated blast hole 3, which is installed at the joint surface of the goaf 6 of the pillar and the stope 8. The goaf 6 of the pillar is filled with a filling body, and the prefabricated blast hole 3 is filled with explosives.

[0065] The blast hole installation structure is simple in structure, cheap in price, simple in process and convenient in installation. It realizes the precise control of the ore body boundary. The construction difficulty of the blast holes at the junction of the stope and the pillar is significantly reduced, the construction accuracy is significantly improved, the dilution rate is reduced by more than 30%, and the loss rate is reduced by more than 50%.

[0066] Among them, the prefabricated blast hole 3 is made of a flexible thick-walled anti-static plastic pipe, and the inner diameter of the prefabricated blast hole 3 can be any size. For example, the inner diameter of the prefabricated blast hole 3 can be 50 mm - 150 mm. In one specific embodiment, preferably, the inner diameter of the prefabricated blast hole 3 is 100 mm.

[0067] On the basis of the above scheme, the prefabricated blast hole 3 is an inclined tubular structure, and there are multiple of them. The multiple prefabricated blast holes 3 are parallel to each other and evenly distributed, and the inclination angle of the prefabricated blast hole 3 is the same as the inclination angle of the ore body.

[0068] The prefabricated blast holes 3 are parallel to the inclination angle of the ore body and evenly distributed, reducing the blast hole density coefficient, increasing the ore broken per meter of blast hole and reducing the unit consumption of explosives. The ore broken per meter of blast hole is also called the blasting volume per meter.

[0069] Among them, the spacing between two adjacent prefabricated blast holes 3 can be selected according to the actual situation. For example, the spacing between two adjacent prefabricated blast holes 3 can be 1 m - 5 m. In one specific embodiment, preferably, the spacing between two adjacent prefabricated blast holes 3 is 2 m.

[0070] Specifically, as Figure 1 shown, the prefabricated blast holes 3 are arranged starting from the ore body boundary 4 on one side and evenly arranged to the ore body boundary 4 on the other side.

[0071] On the basis of the above scheme, it also includes a ground anchor bolt 2. The lower end of the ground anchor bolt 2 is detachably inserted into the bottom plate of the drilling chamber 1 above the roadway roof, the upper end of the prefabricated blast hole 3 extends into the drilling chamber 1, and the upper end of the ground anchor bolt 2 is detachably connected to the upper end of the prefabricated blast hole 3.

[0072] The prefabricated blast hole 3 is convenient to fix, and the ground anchor bolt 2 can be recycled and reused.

[0073] Specifically, in a mine, the space above the roadway is called the drilling chamber 1, and the space below the roadway is called the undercut roadway 9.

[0074] On the basis of the above solution, the ground anchor bolt 2 is vertically arranged, and the horizontal distance from the ground anchor bolt 2 to the joint surface of the pillar goaf 6 and the stope 8 is greater than or equal to 1 m. The depth of the lower end of the ground anchor bolt 2 inserted into the bottom plate of the drilling chamber 1 is greater than or equal to 0.6 m, and the length of the upper end of the ground anchor bolt 2 protruding from the bottom plate of the drilling chamber 1 is greater than or equal to 1 m.

[0075] The structure of the ground anchor bolt 2 is stable and has high reliability.

[0076] Preferably, the upper end of the prefabricated blast hole 3 is fixed to the ground anchor bolt 2 by wire binding. The lateral distance from the ground anchor bolt 2 to the joint surface of the pillar goaf 6 and the stope 8 is greater than or equal to 1 m; the distance between adjacent two ground anchor bolts 2 is the same as the distance between adjacent two prefabricated blast holes 3; the length of the upper end of the ground anchor bolt 2 exposed from the bottom plate of the drilling chamber 1 is greater than or equal to 1 m. In one specific embodiment, preferably, the ground anchor bolt 2 is made of threaded steel. The ground anchor bolt 2 and the prefabricated blast hole 3 are fixed by binding with No. 8 wire, and the binding is not less than 4 turns.

[0077] On the basis of the above solution, it further includes a filling retaining wall 5. The filling retaining wall 5 is vertically fixed in the bottom plate of the roadway, and the lower end of the prefabricated blast hole 3 is detachably connected to the filling retaining wall 5.

[0078] When filling the pillar goaf 6, the filling retaining wall 5 serves as the boundary of the filling body to limit the scope of the filling body. At the same time, the filling body is used to fix the prefabricated blast hole 3 without adding too many additional structures.

[0079] Specifically, the filling retaining wall 5 includes a plurality of cross beams arranged horizontally and spaced apart in the vertical direction, and a plurality of longitudinal beams arranged vertically and spaced apart in the horizontal direction. The plurality of cross beams and the plurality of longitudinal beams are fixed to form a grid-like structure.

[0080] Among them, the lower end of the prefabricated blast hole 3 is fixed to the uppermost cross beam of the filling retaining wall 5 by wire binding. Preferably, the cross beam and the prefabricated blast hole 4 are fixed by binding with No. 8 wire, and the binding is not less than 4 turns. The length of the lower end of the prefabricated blast hole 3 exposed outside the filling retaining wall 5 is greater than or equal to 0.5 m. That is to say, as Figure 2 shown, the lower end of the prefabricated blast hole 3 extends obliquely towards the filling retaining wall 5, passes through the filling retaining wall 5, and the length of the part protruding from the filling retaining wall 5 is greater than or equal to 0.5 m, so as to facilitate adjusting the installation angle of the prefabricated blast hole 3 and facilitating the binding and fixing with the filling retaining wall 5. The part of the prefabricated blast hole 3 protruding from the filling retaining wall 5 can be cut off before blasting.

[0081] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. 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. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0082] In the present invention, unless otherwise clearly specified and defined, 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 simply means 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 simply means that the first feature has a lower horizontal height than the second feature.

[0083] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. 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 invention. 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 a suitable manner in any one or more embodiments or examples. 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.

[0084] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installed", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0085] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for drilling blast holes at the joint of a stope and a pillar, characterized in that, it includes the following steps: Step 1: Pillar extraction; Step 2: Install prefabricated blast holes (3) on the joint surface between the goaf (6) of the pillar and the stope (8); the prefabricated blast holes (3) are inclined tubular structures, there are multiple of them, and the multiple prefabricated blast holes (3) are parallel to each other and evenly distributed, and the inclination angle of the prefabricated blast holes (3) is the same as the inclination angle of the ore body; Step 3: Fill the goaf (6) of the pillar with filling material; Step 4: Charge the prefabricated blast holes (3) and carry out blasting.

2. The method for drilling blast holes at the joint of a stope and a pillar according to claim 1, characterized in that, in Step 2, the upper end of the prefabricated blast hole (3) is detachably connected to the roadway roof through a ground anchor bolt (2), and the lower end of the prefabricated blast hole (3) is detachably connected to the filling retaining wall (5) in the roadway floor.

3. The method for drilling blast holes at the joint of a stope and a pillar according to claim 2, characterized in that, Step 4 specifically includes: removing the ground anchor bolt (2), blocking the prefabricated blast hole (3) to meet the charging condition, charging the prefabricated blast hole (3), and carrying out blasting.

4. The method for drilling blast holes at the joint of a stope and a pillar according to claim 1, characterized in that, between Step 3 and Step 4, it further includes: cutting off the part of the prefabricated blast hole (3) that extends out of the ore body and the filling material.

Images