A bottom structure layout suitable for mining inclined and steeply inclined thin ore bodies

Abstract

This invention discloses a bottom structure layout suitable for mining inclined and steeply inclined thin ore bodies. The upper deep-hole drilling tunnel (3) is excavated along the ore body strike between the upper deep-hole drilling tunnel connecting tunnel (2) and the ore body section between the loading roadway (5) to form the lower middle-hole drilling tunnel (6). In the lower middle-hole drilling tunnel (6), with the cutting riser as the center, the middle hole drilling rig or mining drilling rig is used to drill the upward pulling bottom middle hole (8). In the upper deep-hole drilling tunnel (3), with the cutting riser as the free face, the mining drilling rig is used to drill the downward recovery deep hole (9). With the cutting riser as the free face, the blast holes are laterally blasted in stages, sections and rows. After each blast, a shovel loading device is used in the loading roadway (5) to shovel and transport part or all of the blasted ore (10) out of the mining area. The method of this invention can significantly improve the mechanization and mining efficiency of steeply inclined thin ore body mining, and significantly improve the safety of mining.

Description

Technical Field

[0001] This invention belongs to the field of underground mining technology, specifically relating to an efficient mining method for inclined and steeply inclined thin ore bodies with a thickness of 0.8 to 4.5 m, which is used to replace the shallow hole ore-keeping method currently widely used for inclined and steeply inclined thin ore bodies. Background Technology

[0002] Shallow-hole mining is a traditional method for mining inclined or steeply inclined thin ore bodies (<5m), and it remains the primary method for mining inclined or steeply inclined thin ore bodies in tungsten and gold mines nationwide. The ore blocks in this method are generally 40-60m long and high, with a width equal to the ore body thickness (<5m, mostly less than 2m). During mining, a pre-mining ventilation shaft is first excavated in the center of the ore block, followed by a bottom-level roadway, and finally, reverse dipping upwards for mining. During mining, as the depth increases, access shafts are gradually erected on both sides of the ore block (or, before mining, access shafts are excavated on both sides of the ore block, with a stopway excavated every 4m within the shafts). The ore body dip angle in this method is generally above 60°-65°, the ore and rock are stable, the occurrence is singular, and there is no agglomeration or spontaneous combustion. The main characteristics of this method are:

[0003] (1) It is a type of open-field mining and has the common characteristics of open-field mining. It also involves dividing the ore block into two steps: mining the stope and mining the pillar. The stope is mined first, and then the pillar is mined.

[0004] (2) In this mining method, workers work directly below the exposed surface of the mine roof.

[0005] (3) Shallow hole ore retention method is a layered ore retention method from bottom to top, using shallow holes to thin the ore.

[0006] (4) Each time the ore is mined, about 1 / 3 of it is released from the funnel by its own weight, leaving 2 / 3 of the ore as a temporary work platform for the next rock drilling and blasting operation. After the entire ore chamber is emptied, the remaining 2 / 3 of the ore is released (this is called large-scale ore release).

[0007] (5) Rock drillers work standing on the ore pile.

[0008] Shallow-hole stope mining includes: rock drilling, blasting, ventilation, partial ore release, roughing, leveling, and large-scale ore release. Stope mining is carried out layer by layer from bottom to top, with each layer typically 2-3 meters high. Shallow-hole caving is employed. There are two types of rock drilling: upward drilling and horizontal drilling. When the ore is relatively stable, upward drilling is generally used. It has high drilling efficiency and is easy for workers to operate, but workers work directly under the vibrating ore body, resulting in poor safety and working conditions (water flows downwards during drilling). Furthermore, the frequent replacement of drill rods during drilling affects efficiency. When the ore is less stable, horizontal drilling is generally used. The working face formed after drilling and blasting is relatively flat and smooth, offering better safety. However, the drilling efficiency is lower than with upward drilling, and more large pieces of ore are caved. Currently, in stopes using the stope mining method in thin and very thin veins, upward blasting is the most common method. The charge ratio in the blast hole should not be too small, ideally reaching 60-70%. If the charge ratio is too small, the explosive will be unevenly distributed in the ore, resulting in more large pieces of ore breaking off.

[0009] Shallow-hole stope mining has advantages such as simple structure, convenient management, relatively small amount of mining and cutting work, low ore loss and dilution, and low mining cost. However, traditional shallow-hole stope mining requires personnel to stand on the ore pile in the stope for drilling and blasting, with the upper part being the empty roof. During operation, all personnel must climb into the stope through the footpaths at both ends, and drilling rigs and support materials are all carried to the working face by manpower. This method has several disadvantages:

[0010] (1) All mining operations have a low degree of mechanization, resulting in high labor intensity and low efficiency for personnel;

[0011] (2) Most of the operations are carried out by personnel under the open roof of the mining area. When the stability of the ore rock mass is poor, accidents such as roof collapse and slab fall are likely to occur, resulting in poor safety and reliability.

[0012] (3) When there is no central ventilation atrium, the ventilation effect is poor, and accidents such as poisoning and suffocation are likely to occur.

[0013] (4) When an arch occurs in the ore pile at the mining site, it can easily cause accidents that bury personnel and equipment.

[0014] Due to the aforementioned drawbacks of the shallow-hole stope method, particularly its high labor intensity, low production efficiency, and poor safety, it is becoming increasingly difficult to recruit workers willing to perform this work underground. Therefore, finding new mining methods for such steeply dipping or thin-dipping ore bodies is imperative. A few mines in China, such as Zhangyuan Tungsten Industry, have independently conducted pilot projects similar to sublevel stope mining, but with minimal success.

[0015] In the past, due to equipment limitations, my country's mining industry primarily used shallow-hole drilling rigs, with a smaller number using medium-hole rigs, but the drilling depth was generally below 20 meters. In the past two decades, with the emergence of imported and domestically produced high-efficiency hydraulic rock drilling rigs, the mining of medium-thick ore bodies has largely shifted to hydraulic rig drilling, and hole depths from over ten meters to nearly one hundred meters no longer present technical difficulties. The emergence of high-efficiency rock drilling equipment has provided favorable equipment conditions for the implementation of this invention.

[0016] To address the problems of low mining efficiency and poor safety in the current mining of inclined and steeply inclined thin ore bodies, Chinese Patent 202010271737.2 discloses a mining method for steeply inclined thin veins, which includes the following steps: 1) Preparation: Opening a stopway on the ore body, the stopway being arranged along the strike of the ore body, the stopway having a stopway roof; 2) Drilling: Drilling holes in the current stopway roof, the holes including multiple blast holes and multiple anchor bolt holes, the depth of the blast holes being greater than the depth of the anchor bolt holes. The method involves the following steps: 1) Depth of the anchor bolt holes; 2) Support: Install the anchor bolts into the anchor bolt holes; 3) Mining: After the support step is completed, mine the ore; 4) Filling the blast holes with explosives; 5) Blasting: After the mining step is completed, blasting is carried out to knock down the current stope roof; 6) Hazard removal: After the blasting step is completed, if the next stope roof is exposed, pry away the exposed next stope roof and surrounding rock to remove hazards, and then return to the drilling step. This mining method can improve mining efficiency and safety. However, overall, this method is not suitable for large-scale, mechanized applications in inclined or steeply inclined thin ore bodies, and the production efficiency and mechanization level are still not high. Summary of the Invention

[0017] The purpose of this invention is to address the shortcomings of existing inclined or steeply inclined thin ore bodies, such as low mechanization, high labor intensity, low efficiency, and poor safety and reliability, by providing a bottom structure layout suitable for the mining of inclined or steeply inclined thin ore bodies. This layout offers high mechanization, high mining efficiency, and significantly improves safety during the mining of inclined or steeply inclined thin ore bodies. It is applicable to the mechanized mining of inclined and steeply inclined thin ore bodies with a thickness of 0.8 to 4.5 m.

[0018] To achieve the above-mentioned objectives of this invention, a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies is proposed. This invention employs a combined mining process using "deep-hole drilling equipment, medium-deep hole diameter, and medium-shallow hole mesh parameters" instead of the shallow-hole ore retention method. Support pillars are provided on both sides of the ore-to-be-mined chamber. The upper part of the ore-to-be-mined chamber is the upper-middle section bottom pillar, and the lower part of the ore-to-be-mined chamber is the middle section bottom pillar. The specific technical solution is implemented as follows:

[0019] S1: First, in the upper middle section of the ore block, at a distance of 8-15m from the footwall of the ore body, excavate a mid-section external horizontal tunnel parallel to the ore body; then, perpendicular to the mid-section external horizontal tunnel and corresponding to the middle of the pillar, excavate upper deep-hole drilling horizontal tunnels connecting to the two ends of the ore block. Between the upper deep-hole drilling horizontal tunnels connecting to the pillars, excavate upper deep-hole drilling horizontal tunnels along the strike of the ore body. The upper deep-hole drilling horizontal tunnels extend beyond the ore body boundary line between the footwall and footwall by a certain distance, generally more than 0.3m beyond the ore body boundary line, preferably in the range of 0.5m to 3.0m; the thickness of the upper middle section bottom pillar above the upper deep-hole drilling horizontal tunnel should be at least greater than 3.1m, preferably in the range of 3.2-4.5m.

[0020] S2: Corresponding to the upper and middle sections, in the lower middle section of the ore block, within a distance of 7 to 12 meters from the footwall of the ore body, a lower ore loading access connecting roadway is excavated parallel to the ore body and perpendicular to the lower ore loading access connecting roadway. The ore loading access roadway is excavated every 5 to 7 meters to reach the ore body. Then, the ore body sections between the ore loading access roads are connected to form a lower middle hole drilling horizontal roadway. The lower middle hole drilling horizontal roadway extends more than 0.3 meters beyond the ore body boundary line between the upper and lower footwalls, preferably within the range of 0.5 to 3.0 meters.

[0021] S3: After the upper deep-hole drilling tunnel and the lower medium-hole drilling tunnel are formed, the cut-out riser is excavated in the middle of the ore block;

[0022] S4: After the above works are completed, mining begins. In the lower middle hole drilling tunnel, with the cutting head as the center, a middle hole drilling rig or mining drilling rig is used to drill the upward pulling bottom middle hole; in the upper deep hole drilling tunnel, with the cutting head as the free face, a mining drilling rig is used to drill the downward mining deep hole; the depth of the upward pulling bottom middle hole is in the range of 13 to 17m, and the depth of the downward mining deep hole is between 36 and 44m.

[0023] After the drilling of the upward-pulling bottom hole and the downward-returning deep hole is completed, the cutting riser is used as the free face, and the blasting is carried out in stages, sections and rows of the blast holes. In the corresponding ore bodies, the upward-pulling bottom hole is blasted first, followed by the downward-returning deep hole. After each blast, a portion or all of the blasted ore is shoveled out of the stope using shovel loading equipment in the ore loading route. The specific amount of ore removed is uncertain, but the minimum amount of blasted ore removed from the stope must be sufficient to provide the compensation space for the next blast after the ore is removed.

[0024] Preferably, a >3m isolation pillar must be left at the top of the upper deep-hole drilling roadway. This isolation pillar can be either the bottom pillar of the upper-middle section or the top pillar of the middle section.

[0025] The bottom structure layout method of this invention, suitable for mining inclined and steeply inclined thin ore bodies, exhibits the following positive effects after adopting the above technical solution:

[0026] (1) The method of the present invention adopts a combined mining process of "deep hole drilling equipment, medium-deep hole diameter, and medium-shallow hole mesh parameters" to replace the shallow hole ore retention method. It uses deep hole or deep hole plus medium hole equipment for drilling, medium hole diameter, and medium or shallow hole mesh parameters. One mining method integrates the relevant processes of three types of mining methods: shallow hole, medium hole and deep hole, which greatly improves the mining efficiency of inclined and steeply inclined thin ore bodies.

[0027] (2) During mining, drilling and charging are carried out in the horizontal tunnels in the upper and lower middle sections of the vein, which can greatly improve the safety of mining using the existing shallow hole ore-holding method.

[0028] (3) In the upper and lower middle sections along the vein roadway, a medium hole drilling rig or mining trolley is used to drill upward medium holes and downward deep holes respectively. The cut-up well is used as the free surface, and the side collapse mining body is adopted. This greatly improves the mechanization of mining steeply inclined thin ore bodies, greatly reduces the number of on-site workers, and significantly reduces personnel and increases efficiency. Attached Figure Description

[0029] Figure 1 This is a front view of a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies according to the present invention;

[0030] Figure 2 This is a side view of a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies according to the present invention.

[0031] Figure 3 This is a top-view diagram of the bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies according to the present invention, showing the bottom pulling and ore extraction level.

[0032] Figure 4 This is a top view of the middle section of the rock drilling, which is a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies according to the present invention.

[0033] The markings in the diagram are as follows: 1-Intermediate vein external horizontal tunnel; 2-Upper deep-hole drilling horizontal tunnel connecting tunnel; 3-Upper deep-hole drilling horizontal tunnel; 4-Lower ore loading access connecting tunnel; 5-Ore loading access; 6-Lower middle-hole drilling horizontal tunnel; 7-Cutting riser; 8-Upward pulling bottom middle hole; 9-Downward mining deep hole; 10-Collapsed ore; 11-Interstitial pillar; 12-Upper-middle section bottom pillar; 12'-This middle section bottom pillar; 13-Ore body boundary line; 14-Mining stope to be mined. Detailed Implementation

[0034] To better describe the present invention, the following description, in conjunction with the accompanying drawings, provides a more detailed description of a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies.

[0035] This invention discloses a bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies, applicable to the mechanized mining of inclined and steeply inclined thin ore bodies with a thickness of 0.8–4.5 m. (The invention is based on...) Figure 1 The diagram shown is a front view of a bottom structure layout suitable for mining inclined and steeply inclined thin ore bodies according to the present invention, and is combined with... Figure 2 , Figure 3 , Figure 4 It can be seen that there are intermediate columns 11 on both sides of the ore-to-mine chamber 14, the upper part of the ore-to-mine chamber 14 is the upper middle section bottom column 12, and the lower part of the ore-to-mine chamber 14 is the middle section bottom column 12'. The specific implementation steps are as follows:

[0036] S1: First, in the upper middle section of the ore block, at a distance of 8-15m from the footwall of the ore body, a middle-section external horizontal tunnel 1 is excavated parallel to the ore body; then, perpendicular to the middle-section external horizontal tunnel 1 and corresponding to the middle of the inter-pillar 11, an upper deep-hole drilling horizontal tunnel connecting tunnel 2 is excavated at both ends of the ore block; between the upper deep-hole drilling horizontal tunnel connecting tunnel 2, an upper deep-hole drilling horizontal tunnel 3 is excavated along the ore body strike; the upper deep-hole drilling horizontal tunnel 3 extends 0.8m beyond the ore body boundary line 13 of the footwall and footwall of the ore body; the upper middle section bottom pillar 12 of the upper deep-hole drilling horizontal tunnel 3 has a thickness of 3.5m.

[0037] S2: Corresponding to the upper middle section, in the lower middle section of the ore block, within a distance of 7 to 12m from the footwall of the ore body, a lower ore loading access connecting roadway 4 is excavated parallel to the ore body. The lower ore loading access connecting roadway 4 is excavated perpendicular to the lower ore loading access connecting roadway 4. Every 5 to 7m, the ore loading access roadway 5 is excavated to reach the ore body. Then, the ore body sections between the ore loading access roads 5 are connected to form the lower middle hole drilling horizontal roadway 6. The lower middle hole drilling horizontal roadway 6 extends 0.7m beyond the ore body boundary line 13 between the upper and lower walls of the ore body.

[0038] S3: After the upper deep-hole drilling tunnel 3 and the lower medium-hole drilling tunnel 6 are formed, the cutting riser 7 is excavated in the middle of the ore block;

[0039] S4: After the above work is completed, mining begins. In the lower intermediate-hole drilling roadway 6, with the cutting riser 7 as the center, an upward-pulling bottom intermediate hole 8 is drilled using an intermediate-hole drilling rig or mining drilling jumbo. In the upper deep-hole drilling roadway 3, with the cutting riser 7 as the free face, a downward-pulling deep mining hole 9 is drilled using a mining drilling jumbo. The depth of the upward-pulling bottom intermediate hole 8 is in the range of 13-17m, and the depth of the downward-pulling deep mining hole 9 is between 36-44m. A >3m isolation pillar must be left at the top of the upper deep-hole drilling roadway 3. This isolation pillar can be the bottom pillar of the upper-middle section stope or the top pillar of this middle section stope.

[0040] After drilling the upward-pulling bottom hole 8 and the downward-recovery deep hole 9, lateral blasting is carried out on the blast holes in stages, sections, and rows, using the cutting riser 7 as the free face. In the corresponding ore bodies, the upward-pulling bottom hole 8 is blasted first, followed by the downward-recovery deep hole 9. After each blast, a portion or all of the blasted ore 10 is shoveled and transported out of the stope using shovel-loading equipment within the loading route 5. The specific quantity of ore removed is uncertain, but the minimum amount of blasted ore 10 shoveled and transported out of the stope must be sufficient to compensate for the next blasting within the stope space after ore removal. Alternatively, the mined ore can be directly dumped into the ore transport equipment or dumped into the stope pass after being shoveled by the shovel-loading equipment.

[0041] In the method of this invention, the length and angle of the upward pull-down center hole and the downward return mining deep hole are not limited, and the specific value of the hole diameter is not limited. Except for the upper deep hole drilling tunnel and the lower center hole drilling tunnel, which are mandatory projects, the other mining preparation, cutting projects and the lower pull-down center hole can be added or subtracted according to factors such as the mine equipment, ore body occurrence, and existing projects around the mining area. The cross-sectional size of all projects is not limited.

[0042] This invention provides a bottom structure layout suitable for mining inclined and steeply inclined thin ore bodies, which has been successfully applied in engineering practice. The application results show that it has the following outstanding advantages compared with the original shallow hole ore-holding method: First, it can significantly improve the mechanization of mining steeply inclined thin ore bodies, achieving reduced manpower and increased efficiency, with a reduction of more than 50% in on-site mining personnel; second, all mining operations are carried out in the horizontal roadway within the upper, lower, and middle sections of the vein, which can greatly improve the safety conditions during mining using the existing shallow hole ore-holding method; third, it significantly improves the mining efficiency of this type of ore body, increasing mining efficiency by more than 60%.

Claims

1. A bottom structure arrangement suitable for mining inclined and steeply inclined thin ore bodies, used for mechanized mining of inclined and steeply inclined thin ore bodies with a thickness of 0.8 to 4.5 m; wherein intermediate columns (11) are provided on both sides of the mining chamber (14), the upper part of the mining chamber (14) is the upper middle section bottom column (12), and the lower part of the mining chamber (14) is the middle section bottom column (12'), characterized in that A combined mining process using "deep-hole drilling equipment, medium-deep hole diameter, and hole network parameters for medium or shallow holes" will replace the shallow-hole ore-holding method, and will be implemented using the following technical solutions: S1: First, in the middle section of the ore block, at a distance of 8-15m from the footwall of the ore body, a middle section external horizontal tunnel (1) is excavated parallel to the ore body; then, perpendicular to the middle section external horizontal tunnel (1) and corresponding to the middle of the inter-pillar (11), an upper deep-hole drilling horizontal tunnel connecting tunnel (2) is excavated at both ends of the ore block, and an upper deep-hole drilling horizontal tunnel (3) is excavated along the ore body strike between the upper deep-hole drilling horizontal tunnel connecting tunnel (2). The upper deep-hole drilling horizontal tunnel (3) extends more than 0.3m beyond the ore body boundary line (13) of the footwall and footwall of the ore body, and the thickness of the upper middle section bottom pillar (12) above the upper deep-hole drilling horizontal tunnel (3) is required to be at least greater than 3.1m; the top of the upper deep-hole drilling horizontal tunnel (3) must be reserved with an isolation pillar of >3m, which is the bottom pillar of the upper middle section stope and the top pillar of this middle section stope; S2: Corresponding to the upper middle section, in the lower middle section of the ore block, within a distance of 7 to 12m from the footwall of the ore body, a lower ore loading access connecting roadway (4) is excavated parallel to the ore body, and a ore loading access roadway (5) is excavated perpendicular to the lower ore loading access roadway (4) every 5 to 7m to reach the ore body. Then, the ore body sections between the ore loading access roads (5) are connected to form a lower middle hole drilling roadway (6). The lower middle hole drilling roadway (6) extends more than 0.3m beyond the ore body boundary line (13) between the upper and lower walls of the ore body. S3: After the upper deep hole drilling tunnel (3) and the lower medium hole drilling tunnel (6) are formed, the cutting riser (7) is excavated in the middle of the ore block. S4: After the above works are completed, mining begins. In the lower middle hole drilling tunnel (6), with the cutting head (7) as the center, the middle hole drilling rig or mining drilling rig is used to drill the upward pulling bottom middle hole (8); in the upper deep hole drilling tunnel (3), with the cutting head (7) as the free face, the mining drilling rig is used to drill the downward mining deep hole (9), and the blast holes are blasted laterally in stages, sections and rows; the upward pulling bottom middle hole (8) is blasted first each time. After each blast, a portion or all of the collapsed ore (10) is shoveled out of the mining area using a shovel in the loading route (5). The minimum amount of collapsed ore (10) shoveled out of the mining area must be sufficient to provide compensation space for the next blast after the mining area is opened. The depth of the upward pulling bottom hole (8) is in the range of 13 to 17 m, and the depth of the downward mining hole (9) is between 36 and 44 m.

2. The bottom structure layout method suitable for mining inclined and steeply inclined thin ore bodies as described in claim 1, characterized in that: In step S1, the distance between the upper deep-hole drilling tunnel (3) and the boundary line (13) of the ore body on the upper and lower walls of the ore body is 0.5m to 3.0m.

3. The bottom structure layout method suitable for mining inclined and steeply inclined thin ore bodies as described in claim 2, characterized in that: In step S2, the distance between the lower central hole drilling tunnel (6) and the boundary line (13) of the ore body on the upper and lower walls of the ore body is 0.5m to 3.0m.

4. The bottom structure layout method suitable for mining inclined and steeply inclined thin ore bodies as described in claim 3, characterized in that: In step S1, the thickness of the upper middle section bottom column (12) of the upper deep hole drilling tunnel (3) is in the range of 3.2 to 4.5 m.

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