A safe and efficient mining method for steeply dipping, high-angle dipping thin ore bodies

Abstract

The application discloses a safe and efficient mining method for inclined and steeply inclined thin ore body, which comprises the following steps: excavating upper deep hole rock drilling flat roadways (3) along the ore body strike between upper deep hole rock drilling flat roadways (2), connecting the ore body segments between ore loading roads (5) to form lower medium hole rock drilling flat roadways (6); taking the cutting shaft as the center, drilling upward drawing medium holes (8) by using medium hole drilling machines or mining rock drilling jumbos in the lower medium hole rock drilling flat roadways (6); taking the cutting shaft as the free surface, drilling downward mining deep holes (9) by using mining rock drilling jumbos in the upper deep hole rock drilling flat roadways (3); taking the cutting shaft as the free surface, performing lateral caving blasting on the blast holes in batches, in sections and in rows; and after each blasting, shoveling and loading equipment is used to shovel and load part or all of the caving ores (10) in the ore loading roads (5) and transport them out of the mining field. The method can greatly improve the mechanization degree and mining efficiency of the steeply inclined thin ore body mining, and significantly improve the safety of the 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 <5m, which can 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. Summary of the Invention

[0016] The purpose of this invention is to address the shortcomings of existing shallow-hole ore-holding methods for mining inclined or steeply inclined thin ore bodies, such as low mechanization, high labor intensity, low efficiency, and poor safety and reliability, by providing a safe and efficient mining method for inclined or steeply inclined thin ore bodies that has a high degree of mechanization, high mining efficiency, and can greatly improve the safety conditions during mining using existing shallow-hole ore-holding methods.

[0017] To achieve the above-mentioned objectives of this invention, a safe and efficient mining method for inclined and steeply inclined thin ore bodies is proposed. This method employs a combined mining process using "deep-hole drilling equipment, medium-deep hole diameter, and medium-shallow hole mesh parameters" to replace the shallow-hole ore retention method. Support pillars are installed 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 implementation steps are as follows:

[0018] 1) First, in the upper middle section of the ore block, at a distance of 7-12m from the footwall of the ore body, excavate a middle section external horizontal tunnel parallel to the ore body; then, perpendicular to the middle section external horizontal tunnel and corresponding to the middle of the pillar, excavate the upper deep-hole drilling horizontal tunnel connecting tunnels at both ends of the ore block; between the upper deep-hole drilling horizontal tunnel connecting tunnels, excavate the upper deep-hole drilling horizontal tunnel along the strike of the ore body and widen it at least to the boundary line of the ore body; the thickness of the upper middle section bottom pillar above the upper deep-hole drilling horizontal tunnel should be at least greater than 3m.

[0019] 2) 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 and widened to at least the boundary line of the ore body.

[0020] 3) After the upper deep-hole drilling tunnel and the lower medium-hole drilling tunnel are formed, a cutting riser is excavated in the middle of the ore block;

[0021] 4) After the above works are completed, mining will begin. In the lower middle hole drilling tunnel, with the cutting head as the center, the middle hole drilling rig or mining drilling rig will be used to drill the upward pulling bottom middle hole; in the upper deep hole drilling tunnel, with the cutting head as the free face, the mining drilling rig will be used to drill the downward mining deep hole.

[0022] 5) 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 blasting holes. In the corresponding ore bodies above and below, the upward-pulling bottom hole is blasted first, and then the downward-returning deep hole is blasted. After each blast, a shovel is used in the ore loading route to shovel and transport part or all of the blasted ore out of the mining area.

[0023] The depth of the upward pull-down center hole is preferably in the range of 13 to 18 m, and the depth of the downward mining depth hole is preferably in the range of 35 to 45 m.

[0024] In step 5), the specific amount of ore extracted is uncertain, but the minimum amount of collapsed ore shoveled out of the mining area must be sufficient to fill the mining area space after extraction to provide compensation space for the next blast.

[0025] The top of the upper deep-hole drilling roadway must be equipped with a >3m isolation pillar. This isolation pillar can be either the bottom pillar of the upper-middle section or the top pillar of the middle section.

[0026] 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.

[0027] The safe and efficient mining method for inclined and steeply inclined thin ore bodies of the present invention, after adopting the above technical solution, exhibits the following positive effects:

[0028] (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 combines 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.

[0029] (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.

[0030] (3) In the upper and lower middle sections along the vein, 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, which greatly improves the mechanization of mining of steeply inclined thin ore bodies and achieves the goal of reducing manpower and increasing efficiency. Attached Figure Description

[0031] Figure 1This is a front view of a safe and efficient mining method for inclined and steeply inclined thin ore bodies according to the present invention;

[0032] Figure 2 This is a side view of a safe and efficient mining method for inclined and steeply inclined thin ore bodies according to the present invention.

[0033] Figure 3 This is a top-down view of the bottom pulling and ore extraction level of a safe and efficient mining method for inclined and steeply inclined thin ore bodies according to the present invention;

[0034] Figure 4 This is a top-view view of the middle section of the rock drilling method for a safe and efficient mining method for inclined and steeply inclined thin ore bodies according to the present invention.

[0035] 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

[0036] To better describe the present invention, the following detailed description, in conjunction with the accompanying drawings, provides a safe and efficient mining method for inclined and steeply inclined thin ore bodies.

[0037] Depend on Figure 1 The diagram shown is a front view of a safe and efficient mining method for 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:

[0038] 1) First, in the upper middle section of the ore block, at a distance of 7-12m from the footwall of the ore body, excavate a middle section external horizontal tunnel 1 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, excavate the upper deep hole drilling horizontal tunnel connecting tunnel 2 at both ends of the ore block; between the upper deep hole drilling horizontal tunnel connecting tunnel 2, excavate the upper deep hole drilling horizontal tunnel 3 along the ore body strike and widen it at least to the ore body boundary line 13; the thickness of the upper middle section bottom pillar 12 above the upper deep hole drilling horizontal tunnel 3 should be at least greater than 3m.

[0039] 2) Corresponding to the upper and middle sections, 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 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, and then the ore body sections between the ore loading access roads 5 are connected to form a lower middle hole drilling horizontal roadway 6 and widened to at least the ore body boundary line 13.

[0040] 3) After the upper deep-hole rock drilling tunnel 3 and the lower medium-hole rock drilling tunnel 6 are formed, the cutting riser 7 is excavated in the middle of the ore block;

[0041] 4) After the above works are completed, mining will begin. In the lower intermediate drilling roadway 6, with the cutting riser 7 as the center, an upward pulling bottom intermediate hole 8 will be drilled using an intermediate drilling rig or a mining drilling rig. The depth of the upward pulling bottom intermediate hole 8 will be in the range of 13-18m. In the upper deep drilling roadway 3, with the cutting riser 7 as the free face, a downward mining deep hole 9 will be drilled using a mining drilling rig. The depth of the downward mining deep hole 9 will be between 35-45m. The top of the upper deep drilling roadway 3 must be reserved with an isolation pillar of >3m. This isolation pillar can be the bottom pillar of the upper-middle section stope or the top pillar of this middle section stope.

[0042] 5) 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 out of the stope using shovel loading equipment within the ore loading route 5. The specific amount of ore removed is uncertain, but the minimum amount of blasted ore 10 shoveled out of the stope must be sufficient to compensate for the space in the stope after ore removal for the next blast. Of course, 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.

[0043] This invention provides a safe and efficient mining method for 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 vein in the upper, lower, and middle sections, 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 safe and efficient mining method for steeply and steeply dipping thin ore bodies, with inter-pillars (11) arranged on both sides of the ore room (14) to be mined, the upper part of the ore room (14) being the upper middle section bottom pillar (12), and the lower part of the ore room (14) being the current middle section bottom pillar (12'), characterized in that The following steps are adopted: 1) Firstly, a middle section vein outside horizontal roadway (1) is excavated in the range of 7-12 m from the footwall of the ore body to the middle of the ore block parallel to the ore body; then, an upper deep hole drilling horizontal roadway connecting roadway (2) is excavated at both ends of the ore block vertically to the middle of the middle section vein outside horizontal roadway (1) and corresponding to the middle of the pillar (11); an upper deep hole drilling horizontal roadway (3) is excavated along the strike of the ore body between the upper deep hole drilling horizontal roadway connecting roadway (2) and the ore body boundary line (13) at least; the thickness of the upper middle section bottom pillar (12) of the upper deep hole drilling horizontal roadway (3) is required to be at least 3 m; 2) A lower ore loading access connecting roadway (4) is excavated in the range of 7-12 m from the footwall of the ore body to the lower middle section of the ore block parallel to the ore body corresponding to the upper middle section; a lower ore loading access (5) is excavated every 5-7 m vertically to the lower ore loading access connecting roadway (4) to reach the ore body, and then the ore body section between the lower ore loading accesses (5) is connected to form a lower middle hole drilling horizontal roadway (6) at least to the ore body boundary line (13); 3) After the upper deep hole drilling horizontal roadway (3) and the lower middle hole drilling horizontal roadway (6) are formed, a cutting raise (7) is excavated at the middle position of the ore block; 4) After the above engineering is completed, the mining is started, an upward sublevel hole (8) is drilled in the lower middle hole drilling horizontal roadway (6) with the cutting raise (7) as the center by using a middle hole drilling machine or a mining drilling jumbo; a downward mining deep hole (9) is drilled in the upper deep hole drilling horizontal roadway (3) with the cutting raise (7) as the free surface by using a mining drilling jumbo; 5) After the upward sublevel hole (8) and the downward mining deep hole (9) are drilled, the lateral caving blasting is performed on the blast holes in batches, sections and rows with the cutting raise (7) as the free surface; in the corresponding ore body, the upward sublevel hole (8) is blasted first and then the downward mining deep hole (9) is blasted each time, and after each blasting, a part or all of the caving ore (10) is loaded and transported out of the stope in the ore loading access (5).

2. A safe and efficient mining method for steeply and very steeply inclined thin ore bodies as claimed in claim 1, characterized in that: The upward sublevel hole (8) has a hole depth in the range of 13-18 m, and the downward mining deep hole (9) has a hole depth in the range of 35-45 m.

3. A safe and efficient mining method for steeply and very steeply inclined thin ore bodies as claimed in claim 1 or 2, characterised in that: The minimum amount of the caving ore (10) loaded and transported out of the stope in step 5) must reach the compensation space of the stope space after the ore is mined to meet the next blasting.

4. A safe and efficient mining method for steeply, steep inclined thin ore bodies as claimed in claim 3, characterised in that: The top of the upper deep hole drilling horizontal roadway (3) must be provided with an isolation pillar with a thickness of >3 m, which is the bottom pillar of the upper middle section stope.

5. A safe and efficient mining method for steeply, steep inclined thin ore bodies as claimed in claim 3, characterized in that: The top of the upper deep hole drilling horizontal roadway (3) must be provided with an isolation pillar with a thickness of >3 m, which is the top pillar of the stope.

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