An improved VCR subsequent filling mining method

Abstract

The invention discloses an improved VCR subsequent filling mining method, which belongs to the field of mining technology and comprises the following steps: 1) excavating a rock chamber on the top of a mine room and leaving a discontinuous ore pillar. 2) drilling a pre-splitting blasting shallow hole at the junction of the ore pillar and the top plate of the rock drilling chamber and performing pre-splitting blasting. 3) wedging a certain number of wooden wedges into the pre-cracks. 4) drilling a large-diameter deep hole in the rock drilling chamber to the bottom of the mine room. 5) excavating and exiting the ore at the bottom of the mine room to the boundary of the ore body. 6) using the excavated large-diameter deep hole as a free surface, excavating a cutting shaft by a common method until it is connected with the rock drilling chamber. 7) using the cutting shaft as a free surface, using the large-diameter deep hole to perform staged lateral ore collapse to form a cutting groove. 8) using the cutting groove as a free surface, using the large-diameter deep hole to perform staged lateral ore collapse, and recovering the ore in a backward manner, the ore pillar in the rock drilling chamber naturally collapses with the recovery. 9) After mining is completed, filling is carried out through the ventilated filling tunnel located on the top of the mine room.

Description

Technical Field

[0001] The invention belongs to the technical field of mining, and in particular relates to an improved VCR post-filling mining method. Background Art

[0002] In underground mining, there are three types of mining methods: open stop method, caving method, and backfill method. In the backfill method, there is a subdivision called "VCR backfill mining method". In order to distinguish it from the mining method described in this case, "VCR backfill mining method" will be referred to as "traditional VCR method" below.

[0003] The application scope of the traditional VCR method is steeply inclined ore bodies with an inclination angle greater than 60°. The essence and characteristics of the traditional VCR method are to first dig a rock drilling chamber of the same length and width as the mine room on the top of the mine room and leave a strip ore pillar in the rock drilling chamber to maintain the stability of the chamber, then drill a large-diameter deep hole in the rock drilling chamber to the lower cutting tunnel (i.e., trench), and load a charge with an aspect ratio of no more than 6 from the top when collapsing the ore, and then collapse a certain thickness of ore from bottom to top along the entire length and width of the stope in layers, and mine the entire mining height layer by layer. The main feature of the traditional VCR method of charging is that both ends of the vertical blasthole are open, requiring the use of special devices to keep the charge at the predetermined position.

[0004] Affected by the above essence and characteristics, the traditional VCR method has the following disadvantages:

[0005] (1) It is easy to block the hole and difficult to deal with once it is blocked;

[0006] (2) The ore loss in the lower cutting tunnel (i.e. the trench) is large;

[0007] (3) The strip-shaped pillars left in the rock drilling chamber are prone to form isolated rock masses after blasting, threatening the safety of mining;

[0008] (4) It can only be used for steeply inclined ore bodies, and its application scope is limited;

[0009] (5) Three types of rock drilling equipment are required: shallow hole, medium hole, and deep hole, and the construction process is complicated;

[0010] (6) The charging and blasting operation is complicated and it is difficult to achieve mechanical charging, which results in high labor intensity and low efficiency;

[0011] (7) The last one or two layers of the ore body have the risk of overall collapse, which is particularly prominent when there are hidden faults;

[0012] Patent CN 102953732 A discloses a room-and-pillar type large-diameter deep hole inverted step-shaped segmented lateral caving and subsequent filling mining method for steeply inclined medium-thick or above and gently inclined to extremely thick large ore bodies with stable upper and lower surrounding rocks, comprising the following steps:

[0013] (1) The ore body is divided into zones without pillars, and the zones are divided into continuous mining units in stages, and the mining sequence of "mining one every other unit" is implemented, that is, mining rooms first and then mining pillars;

[0014] (2) The bottom structure of the stope mainly includes the mine-exit tunnel, the mine-exit road, and the rock drilling and ore-collecting tunnel. At the same time, a cutting shaft and an upward fan-shaped medium-deep hole are constructed in the center of the rock drilling and ore-collecting tunnel to form a "V"-shaped trench;

[0015] (3) The top of the stage stope is a rock drilling chamber, with a column in the middle of the chamber. The pillar rock drilling chamber also needs to leave semi-circular columns close to the filling bodies on both sides to support the roof;

[0016] (4) Drilling a large-diameter deep hole downward in the rock drilling chamber, the stope adopts the blasting method of "small-section VCR method cutting groove - high-segment inverted step-shaped lateral caving", and the blasting scale is controlled by the caving step distance and height;

[0017] (5) Retaining ore and removing ore: During the step-shaped lateral collapse blasting, the ore removal from the stope is controlled and the blasting is carried out with retaining ore. Each time, only the ore is removed to the height of the compensation space required for blasting, and the ore dropped by the blasting is used to support the ore rock or filling body;

[0018] (6) Strengthening mining: After the blasting of the stope is completed, strengthen the mining to shorten the exposure time of the empty area of ​​the stope as much as possible so that the stope can be filled as soon as possible;

[0019] (7) After the mining of the ore chamber is completed, the top filling is carried out using graded tailings cementing bodies with different proportions from bottom to top. After the mining of the ore pillar is completed, the main filling method is tailings non-cementing body.

[0020] Patent CN 102953732 A mainly solves item (7) of the shortcomings of the traditional VCR method described in this case. It also involves item (4) of the shortcomings of the traditional VCR method described in this case, but does not clarify how to implement the subsequent filling process. This case solves item (7) of the shortcomings of the traditional VCR method through a process that is different from Patent CN 102953732 A and is simpler and more effective, and clarifies the implementation method of the subsequent filling process that is not specified in Patent CN 102953732 A.

[0021] Patent CN 104594903 A discloses a method for ore dropping for full-section high-combination rock drilling and blasting. The method comprises the following steps:

[0022] a. Mine room preparation: excavate the top of the selected mining area to form a rock drilling chamber, and pull the bottom of the selected mining area below the rock drilling chamber to form a tunnel to complete the preparation of the whole section high mine room.

[0023] b. Determine the VCR groove area and drill blast holes according to the following steps: first, design the blasting for the mine room after the secondary geological delineation, and determine the location and width of the VCR groove area; then take the determined VCR groove area as the center

[0024] The center is set, and the staking lines are measured and laid out to the upper and lower walls of the ore body in turn; finally, downward blasting holes are drilled in the rock drilling chamber of the mine room, and upward blasting holes are drilled in the lower tunnel.

[0025] c. Blasting the cutting skylight and forming the cutting groove is carried out according to the following steps: first, the blasting hole at the skylight part selected in the VCR groove area is loaded with explosive rolls and detonators, and the cutting skylight is blasted by the micro-difference blasting technology; then, the upward blasting hole in the lane where the cutting skylight part has been formed is loaded with explosive rolls and detonators, and the cutting groove is blasted by the micro-difference blasting technology.

[0026] d. Blasting ore dropping is carried out according to the following steps. On the basis of the cutting groove formed in step c, the bottom blasting ore dropping is first carried out through the blasting hole in the lower tunnel of the selected mining area, and then the upper blasting ore dropping is carried out in the rock drilling chamber at the upper part of the selected mining area based on the bottom blasting ore dropping, and the ore dropping in each time is transported out of the mining area in turn, thus completing the blasting mining work of the whole section high combination rock drilling.

[0027] The blasting of cutting grooves in the VCR groove pulling area and the blasting of ore dropping in step d are carried out in an alternating and step-by-step manner extending toward the unmined area.

[0028] Furthermore, the top of the tunnel prepared in step a is an upper arched circular arc top, and the upward blasting holes drilled in the tunnel based on the upper arched circular arc top are arranged in a fan shape.

[0029] Furthermore, in step b, the diameter and depth of the blasting hole drilled in the rock drilling chamber of the mine room are respectively greater than the diameter and depth of the blasting hole drilled in the tunnel.

[0030] Furthermore, in step b, when drilling blasting holes for cutting the skylight in the determined VCR groove area, two layers of blasting holes are drilled outward with the center of the VCR groove area as the reference, each layer has six blasting holes evenly distributed along the circumference, and a crushing hole is arranged in the center.

[0031] A preferred embodiment of the above scheme is that the length of the cut riser prepared by each blasting is 5 to 8 meters extending in the unmined direction.

[0032] Furthermore, the blasting holes drilled in the VCR groove area for blasting the cutting grooves are arranged on both sides of the blasting holes for blasting the cutting rise along the mining direction.

[0033] The preferred method of the above scheme is that after the cutting groove is formed, the bottom blasting is carried out first, and then the upper blasting is carried out. The advance distance of the bottom blasting to the unmined area is at least 5 to 10 rows of blasting holes ahead of the upper blasting to the unmined area.

[0034] Furthermore, after the distance from the bottom blasting mining area to the unmined area is greater than the distance of 5 rows of blasting holes, 3 rows of explosives are loaded in the bottom blasting holes, 2 rows of explosives are loaded in the upper deep holes, and explosives are loaded and blasted simultaneously within the entire height range.

[0035] Furthermore, in step c and step d, the blasting and cutting of the riser, the blasting and cutting of the groove and the blasting and dropping of the ore all adopt the micro-difference blasting and air interval charging blasting process, and the specific operation process is as follows:

[0036] After the blasting hole is drilled, first detect and record the depth and diameter of the blasting hole, then seal the bottom of the blasting hole, and then use gun mud to backfill the bottom of the blocked blasting hole with a thickness of not less than 60 cm. Then, fill the explosives in an alternating order of one layer of cordite and one layer of spacer until it is 2 to 3 meters away from the blasting hole mouth. Finally, backfill the upper part of the blasting hole that is not filled with explosives with gun mud. When filling the bottom layer of cordite, place non-electric detonators or detonating cords in the cordite at the same time. When detonating, use millisecond non-electric detonators outside the hole to carry out micro-difference blasting outside the hole.

[0037] Furthermore, the micro-difference blasting is micro-difference blasting between holes or micro-difference blasting between rows.

[0038] Patent CN 104594903 A mainly solves item (7) of the shortcomings of the traditional VCR method described in this case. It also involves item (1) of the shortcomings of the traditional VCR method described in this case, but cannot completely avoid the risk of hole plugging. This case solves item (7) of the shortcomings of the traditional VCR method and more thoroughly solves item (1) of the shortcomings of the traditional VCR method through a process that is different from Patent CN104594903 A and is simpler and more effective, that is, it more thoroughly avoids the risk of hole plugging. Summary of the invention

[0039] The purpose of the present invention is to provide a mining method which can avoid the various disadvantages of the aforementioned traditional VCR method and is different from the currently available technical solutions.

[0040] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0041] An improved VCR post-fill mining method comprises the following steps:

[0042] 1) Dig a drilling chamber with the same length and width as the mine room on the top of the mine room and leave discontinuous square or other shaped pillars in the drilling chamber to maintain the stability of the chamber.

[0043] 2) Drill shallow pre-splitting blasting holes at the junction of discontinuous ore pillars and the top of the rock drilling chamber and carry out pre-splitting blasting so that the junction of the ore pillars and the top of the rock drilling chamber is completely penetrated by the pre-cracks.

[0044] 3) A certain number of triangular wooden wedges are wedged into the pre-cracks to keep the top plate of the drilling chamber in close contact with the ore pillars.

[0045] 4) Drill large-diameter deep holes to the bottom of the mine room at a certain interval in the rock drilling chamber.

[0046] 5) Excavate in and out of the mine at the bottom of the mine room to the boundary of the ore body.

[0047] 6) At one end of the mine room, use the large diameter deep hole drilled as the free surface and use the common method to dig and cut the shaft until it is connected with the rock drilling chamber.

[0048] 7) Using the cutting shaft as the free surface, use the large-diameter deep hole to carry out staged lateral ore collapse to form a cutting groove with the same width as the mine room.

[0049] 8) With the cutting groove as the free surface, the large-diameter deep hole is used to carry out staged lateral caving and backward mining of ore. The discontinuous ore pillars reserved in the rock drilling chamber will naturally collapse as the mining progresses.

[0050] 9) After mining is completed, subsequent filling is carried out through the ventilation filling tunnel located on the top of the mine room.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1) Completely avoid the shortcomings of the traditional VCR method, which is easy to block the hole and difficult to deal with once the hole is blocked. The reason why the traditional VCR method is easy to block the hole is that multiple blastings are required in the same blasthole. Taking the common middle section height of 40m as an example, generally speaking, about 10 blastings are required. The original cracks in the hole wall continue to expand or generate new cracks under the impact and stretching of the blasting shock wave. The explosive gas scours the inner wall of the blasthole at a high speed, causing the original or newly generated cracks to further expand, and finally forming a hole wall collapse and blocking the hole. In this case, the risk of blockage is completely avoided by reducing the number of blastings required in the same blasthole to 1 time and changing the escape channel of the explosive gas from the traditional VCR method through the large-diameter deep hole to escape through the goaf. Compared with patent CN102953732 A, in this patent, 3 blastings are required in the same blasthole. Although the risk of blockage is reduced to a certain extent, the risk of blockage still exists because the number of blastings in the same blasthole is still multiple and the way of escape of the explosive gas has not been changed before the "top of the slope". Compared with patent CN 104594903 A, in this patent, the cut ceiling is formed by VCR grooving, and about 10 blasts are still required in the same blast hole during the VCR grooving, which cannot completely avoid the risk of hole blockage;

[0053] 2) Reduce ore loss in the lower cutting tunnel (i.e., the trench). In the traditional VCR method, the two sides of the trench are unblasted ore and cannot be recovered. In this case, the ore on the side of the trench away from the ore outlet is blasted along with the mining in the mine room, and the "crushing coefficient" is used to reduce the ore loss rate. The ore on the side of the trench close to the ore outlet is recovered through shallow hole blasting after a large amount of ore is discharged from the mine room and before the filling process begins, thereby reducing the ore loss rate. Compared with Patent CN 102953732 A and Patent CN 104594903 A, these two patents do not contain content in this regard;

[0054] 3) Avoids the formation of isolated hanging rock masses and improves the inherent safety level. After the traditional VCR method mine room is mined, the strip pillars reserved in the rock drilling chamber are very likely to form isolated hanging rock masses, posing a threat to the safety of mining operations. In this case, the strip pillars are changed into discontinuous square or other shaped pillars, and pre-splitting blasting shallow holes are drilled at the junction of the discontinuous pillars and the top of the rock drilling chamber, and pre-splitting blasting is performed, so that the junction between the pillars and the top of the rock drilling chamber is completely penetrated by the pre-cracks, so that the discontinuous pillars reserved in the rock drilling chamber can collapse naturally with the progress of mining, thereby avoiding the formation of isolated hanging rock masses and improving the inherent safety level. Compared with Patent CN 102953732 A and Patent CN 104594903 A, these two patents do not have this content;

[0055] 4) It clarifies the layout of the VCR subsequent filling method when it is used for gently inclined ore bodies. The application scope of the traditional VCR method is steeply inclined ore bodies with an inclination angle greater than 60°. This case clarifies the layout of the VCR method when it is used for gently inclined ore bodies, expanding the application scope of the traditional VCR method. Compared with patent CN 102953732 A, this patent only briefly describes the layout of the traditional VCR method applied to gently inclined ore bodies, and does not clarify the operational layout. Compared with patent CN 104594903 A, this patent does not have this aspect;

[0056] 5) Simplify the types of rock drilling equipment. The traditional VCR method requires the use of three different types of rock drilling equipment: shallow hole, medium hole, and deep hole, which are used for drilling horizontal tunnels, trenches, and large-diameter deep holes. This case only requires two types of rock drilling equipment: shallow hole and deep hole, which are used for drilling horizontal tunnels or cutting shafts, and large-diameter deep holes. Compared with patent CN 102953732 A and patent CN104594903 A, these two patents do not contain this content;

[0057] 6) Simplify charging operations, facilitate mechanized charging, reduce labor intensity and improve labor efficiency.

[0058] The main feature of the traditional VCR method of charging is that both ends of the vertical blasthole are open, requiring the use of special devices to keep the explosive package at the predetermined position. Therefore, the charging process is complicated and labor-intensive, and the operating efficiency is low. In this case, the blasthole form is changed to a bottom-closed one, and a charging machine is used to load rock powder emulsion explosives. There is no need to use special devices to charge, which reduces labor intensity and improves operating efficiency. Compared with patent CN 102953732 A and patent CN 104594903 A, these two patents do not have this content;

[0059] 7) Avoid the risk of mine room collapse. The last one or two layers of the ore body in the traditional VCR method have the risk of overall collapse, which is particularly prominent when there are hidden faults; this case avoids this risk by changing the horizontal mine fall to staged lateral mine collapse. Compared with patent CN102953732 A, the staged lateral mine collapse described in this case does not require a "slope top", which is more concise and efficient. Compared with patent CN104594903 A, the main difference between the staged lateral mine collapse described in this case and the mine collapse method described in the patent is the different depths of the large-diameter deep holes. The large-diameter deep holes described in this case are constructed to the bottom plate of the mine, while the large-diameter deep holes described in patent CN 104594903 A are constructed to the level of the trench. The two are basically similar in the drilling of large-diameter deep holes, but the hole arrangement method described in this case is the premise for achieving the intended effects of items 2) and 6) of this case, that is, the beneficial effects of this hole arrangement method are indirectly reflected through the beneficial effects of items 2) and 6). BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A schematic diagram of an improved VCR subsequent filling method;

[0061] Figure 2 It is a schematic diagram of the traditional VCR method;

[0062] Figure 3 A schematic diagram of the layout of a modified VCR subsequent filling method for a gently inclined ore body.

Claims

1. An improved VCR subsequent filling mining method, characterized in that: The steps include: 1) Dig a rock drilling chamber with the same length and width as the mine room on the top of the mine room and leave discontinuous square or other shaped pillars in the rock drilling chamber to maintain the stability of the chamber; 2) Drilling a shallow pre-splitting blasting hole at the junction of the discontinuous ore pillar and the top plate of the rock drilling chamber and performing pre-splitting blasting so that the junction of the ore pillar and the top plate of the rock drilling chamber is completely penetrated by the pre-crack; By changing the strip pillars into discontinuous square or other shaped pillars and drilling shallow pre-splitting blasting holes at the junction of the discontinuous pillars and the top of the rock drilling chamber and performing pre-splitting blasting, the junction of the pillars and the top of the rock drilling chamber is completely penetrated by the pre-cracks, so that the discontinuous pillars reserved in the rock drilling chamber can be naturally collapsed with the progress of mining, thereby avoiding the formation of isolated hanging rock masses; 3) A certain number of triangular wooden wedges are wedged into the pre-cracks to keep the top plate of the rock drilling chamber in close contact with the pillars; 4) Drilling large-diameter deep holes to the bottom of the mine room at a certain interval in the rock drilling chamber; 5) Excavate in and out of the mine at the bottom of the mine room to the boundary of the ore body; 6) At one end of the mine room, use the large-diameter deep hole drilled as the free surface to use the common method to excavate and cut the shaft until it is connected with the rock drilling chamber; 7) Using the cutting shaft as the free surface, use the large-diameter deep hole to carry out staged lateral ore collapse to form a cutting groove with the same width as the mine room; 8) With the cutting groove as the free surface, the large-diameter deep hole is used to carry out staged lateral ore collapse and backward mining of ore. The discontinuous ore pillars reserved in the rock drilling chamber collapse naturally as the mining proceeds; 9) After mining is completed, subsequent filling is carried out through the ventilation filling tunnel located on the top of the mine room.

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