Combined filling mining method for steeply inclined thin vein

Abstract

The invention relates to a combined filling mining method for a steeply inclined thin vein, which comprises the following steps: S1, arranging a stope: arranging the stope along the trend of an ore body, dividing the stope into a plurality of middle sections from top to bottom along the vertical direction of the vein, dividing ore blocks through a pedestrian ventilation raise, and reserving bottom columns at the bottoms of the ore blocks; s2, mining preparation cutting is conducted, specifically, an in-vein haulage roadway is tunneled in the direction of an ore body, and then a pedestrian ventilation raise is tunneled upwards through the in-vein haulage roadway to communicate an upper middle section air return roadway with the middle section in-vein haulage roadway; excavating a undercut roadway into the ore block from the pedestrian ventilation raises on the two sides along the upper boundary of the bottom column, and upwards excavating a one-way draw shaft as a draw shaft on one side, close to the footwall of the ore body, of the middle-section in-vein haulage roadway at the central position in the length direction of the ore block; s3, stoping, ore removal and filling are conducted, specifically, rock drilling and manual charging are conducted on the first layer from the undercut roadway, and the second layer is circularly stoped; and then filling in a filling step-by-step manner. The mining efficiency can be improved, and the labor intensity of workers can be relieved.

Description

Technical Field

[0001] This invention relates to the field of underground mining methods, and more particularly to a combined backfilling mining method for steeply dipping thin veins. Background Technology

[0002] In my country's underground mining, steeply dipping thin veins account for a significant proportion, especially precious metal deposits such as molybdenum, tin, gold, and silver. For example, gold-bearing veins are mostly gold-bearing quartz veins, with thicknesses ranging from 0.8 to 4 meters (thin veins) or less than 0.8 meters (thin veins). For these types of veins, the main current methods are shallow-hole retention and backfilling. Retention methods result in high ore dilution rates, and the ore tends to clump and become suspended during discharge, leading to ore accumulation and making separate mining and beneficiation difficult. Backfilling methods have low production efficiency, complex processes, and high costs. Furthermore, traditional backfilling methods typically require manual transport of ore to the pass after each discharge, resulting in low mining intensity, high labor intensity, and the need to retain a large number of pillars, making resource recovery difficult. In particular, during pillar mining, the mixing of waste rock into the stopes on both sides leads to a sharp increase in dilution, and the reduction of stope filling material reduces support, creating safety hazards.

[0003] Therefore, steeply dipping thin veins have complex occurrence conditions and are difficult to mine. Existing methods are limited, and there is an urgent need to find a new method for efficient and large-scale mining of steeply dipping thin veins. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a combined backfilling mining method for steeply inclined thin veins that improves mining efficiency and reduces manual labor intensity.

[0005] To address the above problems, the present invention provides a combined backfilling mining method for steeply dipping thin veins, comprising the following steps: S1 stope layout: The mining area is arranged along the strike of the ore body and divided into several intermediate sections from top to bottom along the vertical direction of the vein. Each intermediate section is 40-50m high and the ore blocks are divided by pedestrian ventilation shafts. The ore blocks are 50m long and do not have interstitial pillars or top pillars. A bottom pillar with a thickness of 4-6m is left at the bottom of the ore block. S2 sampling and cutting: The vein transport roadway is excavated along the strike of the ore body. Then, a ventilation shaft is excavated upward through the vein transport roadway to connect the upper and middle section return air roadway and the vein transport roadway of this middle section. From the ventilation shafts on both sides, a bottom-pulling roadway is excavated along the upper boundary of the bottom pillar into the ore block. At the center of the vein transport roadway of this middle section in the length direction of the ore block, a ore pass is excavated upward on the side of the footwall of the ore body as a ore pass. S3 mining, ore extraction and backfilling: The first layer starts from the bottom roadway, using a YT28 rock drill to drill upwards, manually loading explosives into the blast holes on the ore body. The layer height is 3.0m. The second layer is mined in cycles. The first two layers are mined by electric scrapers through the ore pass in the stope. During backfilling, 2-3m thick artificial concrete pillars are first poured along the two sides of the stope boundary. Then, the stope void between the two artificial concrete pillars is filled in stages. After backfilling, the ore is transported to the ore pass by a loader. The loader loads the ore in the transport roadway in the middle section of the vein, and then transports it to the mining area ore pass for unloading through the cross vein and the middle section transport roadway.

[0006] The step-by-step filling method in step S3 refers to the use of 1:5 cement mortar to bind and fill the artificial false bottom after the first and second layers are mined. Starting from the third layer, the surrounding rock is mined to fill the goaf. After leveling the waste rock filling body, a concrete base plate with a thickness of not less than 0.5m is poured on the top surface. Sufficient width is formed after the surrounding rock is mined starting from the third layer.

[0007] In step S3, an expansion agent is added to the artificial concrete pillars on both sides of the stope during the final layer pouring.

[0008] In step S3, the bucket capacity of the loader is 0.75~1.7m³. 3 .

[0009] Compared with the prior art, the present invention has the following advantages: 1. This invention provides artificial concrete pillars to support the surrounding rock on both sides of the stope while mining the ore block, which reduces ore loss caused by the presence of interstitial and top pillars within the ore block, and avoids the technical difficulties and repetitive work caused by the subsequent mining of such pillars.

[0010] 2. In this invention, the first and second layers are filled with cement mortar to form an artificial false bottom, creating favorable conditions for subsequent bottom column mining.

[0011] 3. In this invention, the collapsing surrounding rock from the third layer is used to fill the goaf, which reduces the complicated process of tailings cementing and filling, and provides effective space for subsequent shovels to enter the site for mechanized operations, thereby improving mining efficiency and reducing manual labor intensity.

[0012] 4. In this invention, since most of the ore in the mining area is extracted by a loader, only one chute needs to be left in a mining area, which reduces the number of chutes that need to be left every 10m in the traditional wall cutting and filling method. Attached Figure Description

[0013] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0014] Figure 1 This is a schematic diagram of the elevation layout of the present invention.

[0015] Figure 2 This is a cross-sectional view (I-I) of the present invention.

[0016] Figure 3 This is a cross-sectional view of section II-II in this invention.

[0017] Figure 4 This is a schematic diagram of the initial stage of ore block mining in this invention.

[0018] In the diagram: 1-Upper-middle section return airway; 2-Pedestrian ventilation shaft; 3-Artificial concrete pillar; 4-Concrete floor slab; 5-Waste rock filling body; 6-Artificial false floor; 7-Bottom pillar; 8-Passway; 9-Transport roadway within the vein in this middle section; 10-Blast hole; 11-Ore body; 12-Surrounding rock; 13-Crossing vein; 14-Middle section transport level roadway; 15-Pulling roadway. Detailed Implementation

[0019] A combined backfilling mining method for steeply dipping thin veins includes the following steps: S1 stope layout: like Figure 1 As shown, the mining area is arranged along the strike of the ore body 11 and is divided into several intermediate sections from top to bottom along the vertical direction of the vein. The height of each intermediate section is 40~50m. The mining blocks are divided by the pedestrian ventilation well 2. The mining blocks are 50m long and do not have interstitial pillars or top pillars. A bottom pillar 7 with a thickness of 4~6m is left at the bottom of the mining block.

[0020] S2 sampling and cutting: like Figure 4 As shown, a transport roadway is excavated along the strike of ore body 11. Then, a ventilation shaft 2 is excavated upward through the transport roadway to connect the upper and middle section return air roadway 1 and the middle section transport roadway 9. From the ventilation shafts 2 on both sides, a bottom roadway 15 is excavated along the upper boundary of the bottom pillar 7 into the ore block. At the center of the length of the ore block, a ore pass 8 is excavated upward on the side of the lower plate of the middle section transport roadway 9 near the footplate of ore body 11 as an ore pass.

[0021] S3 mining, ore extraction and backfilling: like Figures 1-3As shown, the first layer starts from the bottom roadway 15, and rock drilling is carried out upwards using a YT28 rock drill. The explosives are manually loaded into the blast holes 10 on the ore body 11. The layer height is 3.0m. The second layer is mined in cycles. The first two layers are mined by using electric scrapers to extract ore through the chute 8 in the stope. When backfilling, 2-3m thick artificial concrete pillars 3 are first poured along the two sides of the stope boundary. Then, the stope void between the two artificial concrete pillars 3 is filled in a step-by-step manner. The phased backfilling method refers to the use of 1:5 cement mortar to bind and backfill the first and second layers after mining, forming an artificial false bottom 6 to create conditions for subsequent bottom pillar 7 mining. Starting from the third layer, the surrounding rock 12 is mined to backfill the goaf. After leveling the waste rock backfill 5, a concrete base slab 4 with a thickness of not less than 0.5m is poured on the top surface to prevent fine ore from entering the backfill during the next ore run and to prevent fine ore from mixing into the backfill during electric scraper mining. It also provides a working face for the loader for ore extraction from the third layer and subsequent layers. After the surrounding rock 12 is mined from the third layer, sufficient width is formed. After backfilling, ore extraction is switched to loader transporting ore to the pass 8. The loader loads ore in the transport roadway 9 within the mid-section vein, and then transports it to the mining area pass for unloading through the cross vein 13 and the mid-section transport level roadway 14.

[0022] Among them, the artificial concrete pillars 3 on both sides of the mine stope are reinforced with an expansion agent during the final layer pouring to achieve active roof connection.

[0023] The bucket capacity of the loader is 0.75~1.7m³. 3 To adapt to narrow spaces. Example

[0025] A gold deposit has an ore body with a length of 40–446 m, a thickness of 0.66–2.07 m, a dip angle of 57°–80°, and a dip direction of 163°–234°. An experimental block was selected in the 1758 m section.

[0026] S1 mining area layout: The mining area is arranged along the strike of the ore body and is divided into several intermediate sections from top to bottom along the vertical direction of the vein. Each intermediate section is 50m high and is divided into ore blocks by pedestrian ventilation shafts. The ore blocks are 50m long and do not have interstitial pillars or top pillars. A 5m thick bottom pillar is left at the bottom of the ore block.

[0027] S2 Preparatory Cutting: Excavate the intravein transport roadway along the strike of the ore body, and then excavate the pedestrian ventilation shaft upward through the intravein transport roadway to connect the upper and middle section return air roadway and the middle section transport roadway; from the pedestrian ventilation shafts on both sides, excavate the bottom roadway along the upper boundary of the bottom pillar into the ore block; at the center of the length direction of the ore block, excavate a ore pass upward along the side of the middle section intravein transport roadway near the footwall of the ore body as the ore pass.

[0028] S3 Mining, Ore Extraction, and Backfilling: The first layer starts from the bottom roadway, using a YT28 rock drill to drill upwards, manually charging explosives, with a layer height of 3.0m. The second layer is mined in cycles. The first two layers are mined using electric scrapers through the ore pass within the stope. During backfilling, a 3m thick artificial concrete pillar is first poured along both sides of the stope boundary. The backfilling of the stope void between the pillars is carried out in the following steps: After the first and second layers are mined, 1:5 cement mortar is used to bind and fill the void to form an artificial false bottom, creating conditions for subsequent bottom pillar mining. Starting from the third layer, the surrounding rock is mined to fill the goaf. After leveling and filling the waste rock, a concrete base plate with a thickness of not less than 0.5m is poured on the top surface to prevent fine ore from entering the backfill during the next ore extraction and to prevent fine ore from mixing into the backfill during electric scraper shoveling. It also provides a working face for the loader for ore extraction from the third layer and subsequent layers. After the surrounding rock is mined from the third layer and a sufficient width is formed, ore extraction is converted to loader transportation of ore to the ore pass.

[0029] Specifically, the loader loads ore in the transport roadway within the mid-section vein, and then transports it to the mining area pass for unloading via the cross-vein and mid-section transport roadways.

[0030] The bucket capacity of a loader should be selected with a capacity of 0.75m³ to suit narrow spaces.

[0031] An expansion agent was added to the artificial concrete pillars on both sides of the stope during the final layer pouring to achieve active roof support.

Claims

1. A combined backfilling mining method for steeply dipping thin veins, comprising the following steps: S1 stope layout: The mining area is arranged along the strike of the ore body (11) and divided into several intermediate sections from top to bottom along the vertical direction of the vein. Each intermediate section is 40-50m high and the ore blocks are divided by the pedestrian ventilation well (2). The ore blocks are 50m long and no interstitial pillars or top pillars are left. A bottom pillar (7) with a thickness of 4-6m is left at the bottom of the ore block. S2 sampling and cutting: Along the strike of the ore body (11), a transport roadway is excavated within the vein. Then, through the transport roadway within the vein, a pedestrian ventilation shaft (2) is excavated upward to connect the upper and middle section return air roadway (1) and the transport roadway within the vein of this middle section (9). From the pedestrian ventilation shafts (2) on both sides, a bottom-pulling roadway (15) is excavated along the upper boundary of the bottom pillar (7) into the interior of the ore block. At the center of the length direction of the ore block, a ore pass (8) is excavated upward on the side of the footwall of the vein of this middle section (9) near the ore body (11) as an ore pass. S3 mining, ore extraction and backfilling: The first layer starts from the bottom roadway (15), and the YT28 rock drill is used to drill upwards. The explosives are manually loaded into the blast holes (10) on the ore body (11). The layer height is 3.0m. The second layer is mined in cycles. The first two layers are mined by electric scraper through the ore pass (8) in the stope. When filling, 2-3m thick artificial concrete pillars (3) are poured along the two sides of the stope. Then, the stope void between the two artificial concrete pillars (3) is filled in a step-by-step manner. After filling, the ore is transported to the ore pass (8) by a loader. The loader loads the ore in the transport roadway (9) in the middle section of the vein, and then transports it to the ore pass in the mining area through the vein (13) and the middle section transport roadway (14) for unloading.

2. The combined backfilling mining method for steeply dipping thin veins as described in claim 1, characterized in that: The step-by-step filling method in step S3 refers to the use of 1:5 cement mortar to bind and fill the artificial false bottom (6) after the first and second layers are mined. Starting from the third layer, the surrounding rock (12) is mined to fill the goaf. After leveling the waste rock filling body (5), a concrete base plate (4) with a thickness of not less than 0.5m is poured on the top surface. After the surrounding rock (12) is mined from the third layer, a sufficient width is formed.

3. The combined backfilling mining method for steeply dipping thin veins as described in claim 1, characterized in that: In step S3, an expansion agent is added to the artificial concrete pillars (3) on both sides of the mine gate during the last layer of pouring.

4. The combined backfilling mining method for steeply dipping thin veins as described in claim 1, characterized in that: In step S3, the bucket capacity of the loader is 0.75~1.7m³. 3 .

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