Construction method for stoping top edge jamb by utilizing lateral blasting of free surface of goaf

Abstract

The invention provides a construction method for stoping a top edge ore pillar by using lateral blasting of a free surface of a goaf, and relates to the technical field of mining, and the construction method comprises the following steps: S1, dividing an ore body into a primary mining area and a secondary mining area according to the distribution condition of the underground ore body; s2, the primary mining area is mined to form a goaf, the goaf is not filled to form a goaf boundary, and a vertical blasting free surface is formed between the goaf and the secondary mining area; and S3, a plurality of blasting holes are constructed downwards in the top of the secondary mining area, the corresponding blasting holes are filled with explosives, and a stope at the bottom of the secondary mining area serves as an ore removal channel. The ore subjected to secondary stoping can directly fall into the stope at the bottom to be collected and transported in a centralized mode, and the overall mining efficiency is greatly improved.

Description

Technical Field

[0001] The invention relates to the technical field of mining, in particular to a method for constructing a top edge ore pillar by utilizing lateral blasting of a free surface of a goaf area. Background Art

[0002] The surrounding rock of the top of this ore body is marble, and the surrounding rock of the bottom is hornfels. The ore body is layered, with a near north-south trend and a dip to the east with a dip angle of 25°~35°. The ore minerals are pyrrhotite, and the gangue minerals are calcite, dolomite and a small amount of quartz; the blasting ore volume is 4642t, with a gold grade of 2.48g / t and a sulfur grade of 35.86%. (excluding the amount of existing ore).

[0003] During the actual mining process of this type of ore body, the middle section of the upper drilling chamber had been mined to form a goaf, in which some ore was accumulated and the reserved pillars on the bottom plate of the vein connecting channel had not been mined; in the traditional mining process, the goaf needs to be filled and then the reserved pillars on the outside need to be mined; the traditional construction process takes longer and requires more filling materials, and the filling materials in the goaf need to be protected during the next blasting. The filling materials are easily affected by the next blast, resulting in a decrease in overall strength, which reduces the safety of subsequent mining. Summary of the invention

[0004] In view of the above problems, the present invention provides a method for recovering the top edge pillar by lateral blasting of the free surface of the goaf. In the invention, the secondary recovered ore can directly fall into the bottom mining area for centralized collection and transportation, greatly improving the overall mining efficiency.

[0005] To solve the above problems, the technical solution adopted by the present invention is: The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf comprises the following steps: S1, dividing the ore body into a primary mining area and a secondary mining area according to the distribution of the underground ore body; S2, first mining the primary mining area to form the goaf, and the goaf is not filled to form the boundary of the goaf, and a vertical blasting free surface is formed between the goaf and the secondary mining area; S3, constructing a plurality of blasting holes downward from the top of the secondary mining area, and loading explosives in the corresponding blasting holes, and using the mining field at the bottom of the secondary mining area as a mine exit channel; S4, guiding the explosives in the plurality of blasting holes to blast in sequence, and the collapsed ore after the blasting enters the mining field at the bottom of the secondary mining area, and the mine car loads and transports the ore in the mining field.

[0006] The primary mining area and the secondary mining area need to be accurately divided according to the distribution of the overall ore pillars. The primary mining area is larger than the secondary mining area, and the secondary mining area is located on the outer raised part compared to the primary mining area, and the connecting surface between the two is smaller.

[0007] Through the above method, there is no need to fill the primary mining area, and the pillars can be efficiently blasted in batches while ensuring safety and overall strength. Especially for the second mining, the time for blasting and subsequent ore transportation is greatly reduced. The ore from the second mining can directly fall into the mining area at the bottom for centralized collection and transportation, which greatly improves the overall mining efficiency.

[0008] Preferably, a plurality of ore receiving funnels are formed at the upper end of the bottom stope of the secondary mining area. The ore receiving funnels are located at alternating parts on both sides of the bottom stope of the secondary mining area, and there is a predetermined distance between two adjacent ore receiving funnels.

[0009] The receiving hopper here has a large cross-sectional size at the upper end and a small cross-sectional size at the lower end, which can collect the ore falling from the upper end in a centralized manner, further improving the efficiency of ore collection; setting up multiple cross-arranged receiving funnels can increase the ore collection points and area while ensuring the strength of the bottom mining area, thereby improving the overall ore collection efficiency.

[0010] Preferably, in step S3, blasting hole one is first constructed along the direction toward the primary mining area, and then blasting hole two is constructed inside the blasting free surface.

[0011] Preferably, the blasting hole one comprises at least two mutually intersecting blasting assemblies one, and the blasting hole two comprises at least two mutually parallel blasting assemblies two.

[0012] Blasting component one can play a guiding role and decompose the ore pillars in the secondary mining area in a direction relatively perpendicular to the secondary mining area. Then, blasting component two can decompose the ore again from the outside to the inside, so that the ore pillars are decomposed into smaller ores that fall downward for collection.

[0013] Preferably, the blasting holes include a plurality of blast holes distributed in a fan shape, and the plurality of blast holes distributed in a fan shape are all located inside the secondary mining area.

[0014] The fan-shaped blastholes can be used to blast the ore pillars in the corresponding area in a fan-shaped manner, and the blastholes can be constructed at one location, which greatly reduces the difficulty of blasthole construction and improves the effect of blasting mining.

[0015] Preferably, the blasting assembly 1 includes mutually crossed plugs 1P and 2P, and the blasting assembly 2 includes mutually parallel 1P, 2P, and 3P, and there is a set distance between the 1P, 2P, and 3P.

[0016] The cross-arranged blasting components 1 can achieve a better effect of primary decomposition of the ore pillars; the parallel-arranged blasting components 2 can subdivide the secondary decomposition, control the ore pillars to decompose in sequence from the inside to the outside, and realize orderly blasting and ore dropping.

[0017] Preferably, the first charge blasts part of the blast holes at the upper end of the 1P row and part of the blast holes at the upper end of the 2P row; the second charge blasts the remaining blast holes at the lower end of the 1P row, the remaining blast holes at the lower end of the 2P row, and all the blast holes in the 1P row; the third charge blasts all the blast holes in the 2P row; and the fourth charge blasts all the blast holes in the 3P row.

[0018] The first charge blasting can quickly decompose the ore at the upper end, and the ore at the lower end can also play a supporting role to avoid rapid overall collapse; through subsequent blasting, the entire ore pillar can be quickly decomposed in a predetermined order, greatly improving the efficiency of the overall construction.

[0019] Preferably, the time interval between each charge explosion is the same, which is 20 milliseconds.

[0020] Preferably, in step S3, electric rake equipment is first used to rake the ore from the electric rake road at the bottom of the secondary mining area to the return air transport road for loading, and the unobstructed mining area at the bottom of the secondary mining area serves as the ore exit channel.

[0021] The beneficial effects of the present invention are: Compared with the prior art, this technical solution does not require filling of the primary mining area, and can efficiently blast the pillars in batches while ensuring safety and overall strength. Especially for the second mining, the time for blasting and subsequent ore transportation is greatly reduced, and the ore from the secondary mining can directly fall into the mining area at the bottom for centralized collection and transportation, greatly improving the overall mining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is the -55m plan view of the present invention (the green area in the attached figure is the goaf, the red area is the body to be mined, and the pink lines are the directions of the blastholes).

[0023] Figure 2 This is the -95m plan view of the present invention (the blue area in the attached figure is the S17# stope, the red dotted area is the S7 stope, and the black dotted area is the S6 stope).

[0024] Figure 3 These are the 1P and 2P cross-sectional views of the present invention (the green area in the figure is the goaf, and the red area is the body to be mined).

[0025] Figure 4 These are the 3P, 1P and 2P cross-sectional views of the present invention (the green area in the attached figure is the goaf and the red area is the body to be mined).

[0026] Figure 5 It is a schematic diagram of the blasting structure of the present invention.

[0027] Figure 6 This is a diagram of the deep hole charging structure of the present invention.

[0028] Figure 7 For the present invention Figure 2 Schematic diagram of the AA section structure (the green area in the figure is the goaf and the red area is the body to be mined).

[0029] Figure 8 This is a cross-sectional view of the S6# electric rake track in the middle section of -95m of the present invention (the green area in the figure is the goaf, and the red area is the downward funnel).

[0030] Fig. 9 This is the cross-sectional view of the S7# electric rake track in the middle section of -95m of the present invention (the green area in the attached figure is the goaf).

[0031] Fig.10 This is the plan view of the S17# electric cutting layer in the middle section of -95m of the present invention (the green area in the attached figure is the goaf). DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0033] See attached Figure 1 -Attached Fig.10 , using the free surface of the goaf to blast the top edge of the mining pillar construction method, technical features: 1. The middle section of the upper rock drilling chamber at -55m was mined to form a goaf area, the overall height of which is between -95m and +5m. There is ore in the accumulation part of the -55m platform connecting road in the goaf, and the reserved ore pillars on the bottom plate of the -55m cross-vein connecting road have not been mined (belonging to the top edge ore pillars in the middle section of -95m); 2. Initially, the S6# stope (mining elevation -79m level) and S7# stope (mining elevation -72m level) were mined in the middle section from -95m to -55m. Afterwards, the S17# stope was constructed vertically below the S6# and S7# stopes to mine the bottom ore of the S6# and S7# stopes. Since there were some bulges in the stope during the mining of S17 and the mining was incomplete, the horizontal area near the end of the S6# stope, near -55m, was not mined. Therefore, this design blasts to mine the -55m bottom ore pillar (-95m top ore pillar).

[0034] 3. Make full use of the existing projects in the upper and lower middle sections, with small investment, short construction period and quick benefits: (1) The middle section of the -55m intersecting vein connecting tunnel was used as the upper drilling chamber layer to directly construct blasting holes in the tunnel; (2) The free face of the goaf area of ​​the -95mS17# mining field was directly used as the free face for blasting in this pillar recovery, and there was no need to blast the free face in the construction of the vertical slot cutting well; (3) The electric climbing tunnel, return air system and transportation system of the -95mS17# mining field were used to directly transport the ore; (4) The ore was located at the horizontal elevation of -70m~-55m (middle and upper part), which reduced the investment in the lower engineering construction and reduced the disturbance to the original rock mass excavation; (5) The economic value exceeded 6 million yuan.

[0035] Construction steps and sequence: 1. There are ridges of ore in the bottom structure of the S17# stope in the middle section of -95m. Electric rake equipment should be used to rake the ore from the electric rake road of the S17# stope to the return air transport road for loading, and to dredge the electric rake road of the S17# stope; 2. In the -55m middle section of the vein tunnel, 5 rows of blastholes are constructed along the boundary of the goaf. The construction sequence of each row of blastholes is: insert 1P→insert 2P→1P→2P→3P; 3. Deep hole drilling equipment and parameters: SKQ-100 pneumatic down-the-hole drilling rig is used for rock drilling, with a blasthole diameter of 90mm and an emulsion explosive diameter of 70mm.

[0036] Design Description 1. This design is the design drawing for blasting to recover the residual ore along the top of line 7~8 in the middle section from -55m to -95m.

[0037] II. Overview: 1. Geological overview: The surrounding rock at the top of the ore body is marble, and the surrounding rock at the bottom is hornfels. The ore body is layered, with a near north-south trend and a dip to the east with a dip angle of 25°~35°. The ore minerals are pyrrhotite, and the gangue minerals are calcite, dolomite and a small amount of quartz; the blasting ore volume is 4642t, with a gold grade of 2.48g / t and a sulfur grade of 35.86%. (excluding the amount of existing ore) 2. Project Overview: The project has been completed and the current status is as shown in the figure.

[0038] 3. Design basis, design parameters and blasting sequence: 1. Use the bottom pillar stage empty field method and deep hole mining.

[0039] 2. Mining method: The mine adopts the open-pit method, followed by backfilling and deep-hole mining.

[0040] 3. The main parameters of deep hole mining blasting are as follows: the diameter of the blasthole is 90mm, and a small vertical down-the-hole drill is used for rock drilling. The normal deep hole network parameters are 2.1*2.1m. After the rock drill constructs all the blastholes of 1P, 2P, 1P, 2P, and 3P in sequence, the blasting is carried out in batches. During the blasting, the goaf formed by the mining of S6 and S17# mining areas is first used as the free face, and then large-scale lateral caving blasting is carried out on the free face of the goaf. Ordinary emulsion explosives are used for blasting, the diameter of the charge is 70mm, the whole hole is continuously charged, and digital electronic detonators are used for detonation.

[0041] 4. Blasting sequence: First, the first charge is used to blast the 1#, 2#, 3# blast holes of the 1P row and the 1#, 2#, 3#, 4# blast holes of the 2P row (2 days); the second charge is used to blast the 4# blast hole of the 1P row, the 5# blast hole of the 2P row, and all the 1#~8# blast holes of the 1P row. The largest explosion of this blast is 700kg of explosives (4 days); the third charge is used to blast all the 1#~8# blast holes of the 2P row (6 days); the fourth charge is used to blast all the 1#~7# blast holes of the 3P row (8 days); 5. After each charge blasting, the collapsed ore is raked into the 0.9m³ mine car group through the -95mS17# mining field electric rake road by the mine funnel, and the mine car is loaded and transported along the return air transport road.

[0042] 6. The scope of this pillar mining blasting is 379.7 meters deep and 33 holes in total.

[0043] 4. Safety parameters: The total amount of explosives is 1568kg. The maximum explosion (4 stages) is 700kg, R ground = 65 meters, R impact = 40 meters, R person = 200 meters.

[0044] V. Personnel Organization: The blasting is divided into charging group and demolition group. When charging, the bottom of the hole is blocked by 1.0m, and the hole mouth is filled by 2.0m. The hole mouth must be cleaned and the hole depth measured before drilling. Technical personnel are assigned to be responsible for organization, safe construction, charging quality, blasting technology, material removal and other work.

[0045] 6. Ore transportation: The blasted ore is transported by the electric rake ore car group through the -95mS17# electric rake receiving funnel.

[0046] 7. Ventilation: Fresh air flows from the -95m bottom edge and -95m return air transport lane into the S17# mining field electric rake road respectively → flows to the blasting working face; polluted air flows from the blasting working face → flows to the upper middle section -55m return air system, enters the main return air system and is discharged to the surface.

[0047] 8. Safety: 1. Strengthen on-site safety management. All blasting preparations must be done carefully before blasting. The number of detonator sections must be marked on site, and the bottom of ultra-deep holes must be plugged.

[0048] 2. Before blasting, samples must be taken for testing of the concentration of water-soluble Fe2+ and Fe3+, and the hole temperature must be measured. Blasting can only be carried out if the requirements are met.

[0049] 3. Organize large-scale blasting strictly in accordance with blasting regulations and design requirements. During blasting, underground workers must evacuate the mine half an hour in advance.

[0050] 4. Before blasting, confirm the blasting line and number of holes on site. Before blasting, carefully check whether the rock on the top board of the chamber is loose. Carefully clean the top board, eliminate hidden dangers, do a good job of protecting the edge of the chute and the empty area. Operators must wear safety belts and confirm safety before working.

[0051] 5. After the blasting, the ventilation inspection team shall conduct ventilation and on-site safety inspections on the middle section of the underground area affected by the blasting, and confirm that there is no blasting smoke underground before notifying the underground workers to enter the working face; during the mining process, the ore is discharged evenly from each funnel of the electric rake road, and the safety management of the electric rake road, tunnel top and side is strengthened; pay attention to the falling of the roof and strengthen observation.

[0052] 6. During the mining process, special attention should be paid to the ventilation of the mining area. If the ventilation effect is not good, local fans, secondary crushing and other mining safety management measures should be installed on site in a timely manner. Miners are prohibited from standing on the inside of the funnel to work.

[0053] 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, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for recovering the top edge pillar by lateral blasting of the free surface of the goaf, characterized in that: The steps include: S1. Divide the ore body into primary mining area and secondary mining area according to the distribution of underground ore body; S2, firstly, the primary mining area is mined to form a goaf area, and the goaf area is not filled to form the goaf area boundary, and a vertical blasting free surface is formed between the goaf area and the secondary mining area; S3, construct multiple blast holes downward from the top of the secondary mining area, and load explosives in the corresponding blast holes, using the stope at the bottom of the secondary mining area as a mine exit channel; S4. The explosives in the multiple blast holes are guided to blast in sequence. After the blasting, the collapsed ore enters the stope at the bottom of the secondary mining area, and the mine car loads and transports the ore in the stope.

2. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 1 is characterized in that: A plurality of ore receiving funnels are formed at the upper end of the bottom stope of the secondary mining area. The ore receiving funnels are located at alternating parts on both sides of the bottom stope of the secondary mining area, and there is a predetermined distance between two adjacent ore receiving funnels.

3. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 1 is characterized in that: In step S3, blasting hole one is first constructed along the direction toward the primary mining area, and then blasting hole two is constructed inside the blasting free surface.

4. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 3 is characterized in that: The blasting hole 1 at least includes two mutually intersecting blasting components 1, and the blasting hole 2 at least includes two mutually parallel blasting components 2.

5. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 3 or 4, characterized in that: The blasting holes include a plurality of blast holes distributed in a fan shape, and the plurality of blast holes distributed in a fan shape are all located inside the secondary mining area.

6. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 5 is characterized in that: The first blasting assembly includes mutually crossed plugs 1P and 2P, and the second blasting assembly includes mutually parallel 1P, 2P, and 3P, and there is a set distance between the 1P, 2P, and 3P.

7. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 6 is characterized in that: The first charge is to blast part of the blast holes at the upper end of the 1P row and part of the blast holes at the upper end of the 2P row; the second charge is to blast the remaining blast holes at the lower end of the 1P row, the remaining blast holes at the lower end of the 2P row, and all the blast holes in the 1P row; the third charge is to blast all the blast holes in the 2P row; the fourth charge is to blast all the blast holes in the 3P row.

8. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 7 is characterized in that: The time interval between each charge explosion is the same, which is 20 milliseconds.

9. The method for recovering the top edge pillar by lateral blasting of the free surface of the goaf according to claim 1 is characterized in that: In step S3, the electric rake equipment is first used to rake the ore from the electric rake road at the bottom of the secondary mining area to the return air transport road for loading, and the unobstructed mining area at the bottom of the secondary mining area is used as the ore exit channel.

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