Phosphorite bed sill pillar and ore block synergetic stage open stoping subsequent filling mining method

Abstract

The invention belongs to the field of phosphorite filling mining, and particularly relates to a phosphorite bed sill pillar and ore block collaborative stage open stoping subsequent filling mining method which comprises the steps that an ore bed is divided into a plurality of ore blocks in the ore bed trend, and the ore blocks comprise ore chambers and sill pillars; constructing a roadway for transportation and ventilation; mining an ore bed with a small rock stratum firmness coefficient and filling the ore bed; interlayer retaining or blasting treatment; mining an ore bed with a relatively large rock stratum firmness coefficient and filling; and mining an ore bed in the bottom pillar of the previous middle section. The method does not need to fill the mined-out area formed by sill pillar stoping, can reduce the filling process and filling materials, reduces the filling cost and construction procedures, and improves the mining efficiency. According to the method, all mining of the ore bed can be achieved, a top column is not reserved, the bottom column is recycled without filling, the ore recovery rate is close to 100%, and good economic benefits can be generated.

Description

Technical Field

[0001] The invention belongs to the field of phosphate ore filling mining, and in particular relates to a staged empty field and subsequent filling mining method in which a phosphate ore bed bottom pillar and ore blocks cooperate. Background Art

[0002] The Datang mining section of Wengfu Phosphate Mine mainly includes two ore layers, namely, ore layer a and ore layer b, with a dip angle of 85°; the two ore layers are respectively located in the second section of the Doushantuo Formation of the Lower Sinian System (Z1d 2 ) and the fourth paragraph (Z1d 4 ) stratum, there is a relatively stable dolomite interlayer between the two mineral layers (Z1d 3 ), with a total thickness of 1.38 to 5.25 m and an average thickness of 2.59 m. The a ore layer is generally 7.6 to 12.4 m thick, with an average thickness of 11.48 m, and is mainly composed of gray-green and gray-black thin-plate sand-mud phosphorite; the bottom of the a ore layer is light gray and gray medium-thick layered fine-grained dolomite, and above the a ore layer is Z1d 3 Light gray, grayish white thick to massive fine to powder crystal dolomite interlayer; b ore layer is generally 7.29 to 31.63m thick, with an average of 17.35m, mainly banded dolomitic phosphorite, siliceous massive dolomitic phosphorite, striped dolomitic phosphorite, massive dolomitic phosphorite, pseudo-oolitic dolomitic phosphorite, dense massive phosphorite, and argillaceous phosphorite; below b ore layer is Z1d 3 Dolomite interlayers, the top of the B ore layer is light gray and grayish white layered fine to medium-crystalline phosphorus-containing dolomite and dolomite.

[0003] For the above-mentioned double ore layers with interlayers in close proximity, it is more appropriate to adopt the deep hole mining stage empty field and subsequent filling mining method in combination with the thickness and inclination of the ore layers. However, how to optimize the mining sequence of ore layers a and b, determine the appropriate interlayer treatment method to improve the stability and safety of ore layer mining, and how to optimize the retention (and recovery) of the top and bottom pillars in the middle section to improve the recovery rate and efficiency have become important research topics. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a staged empty field and subsequent filling mining method in which the bottom pillar of the phosphate ore bed and the ore block cooperate, comprising the following steps:

[0005] S1: In this middle section, the ore layer is divided into several blocks along the ore layer direction; for each block, it is divided into a mine room and a bottom pillar along the height direction, and the thickness of the block is the total thickness of the ore layer and the interlayer; the upper part of the mine room is the bottom pillar left after the mine room of the previous middle section ore block is filled;

[0006] S2: construct the middle section transport tunnel at the bottom of the middle section bottom pillar roof side along the ore seam direction, and construct the mine connection tunnel at the bottom of the middle section mine room roof side along the ore seam direction; construct the middle section return air tunnel at the bottom of the middle section bottom pillar bottom side along the ore seam direction, and construct the mine return air tunnel at the bottom of the middle section mine room bottom side along the ore seam direction;

[0007] An upper middle section transport lane is left on the top plate side of the bottom pillar of the upper middle section as the auxiliary transport lane of this middle section; an upper middle section return air lane is left on the bottom plate side of the bottom pillar of the upper middle section as the rock drilling return air lane of this middle section; in each ore block of the upper middle section, an upper middle section through-vein lane is horizontally constructed to connect the upper middle section transport lane and the upper middle section return air lane, which serves as the rock drilling lane of this middle section; rock drilling chambers are constructed along the strike in the a ore layer and the b ore layer of each ore block;

[0008] Extend the return air shaft to the bottom of this middle section, construct a horizontal tunnel to connect the return air shaft with the rock drilling return air tunnel, the mine return air tunnel, and the middle section return air tunnel; in this middle section, for each ore block, construct a mine roadway from the mine connection tunnel to the mine return air tunnel, and construct a stope chute from the side of the mine connection tunnel away from the ore layer to connect the middle section transport tunnel;

[0009] S3: First, the a ore layer with a smaller rock solidity coefficient is mined, and a large-diameter deep hole is constructed from the rock drilling chamber to the a ore layer in the mine room. After charging, blasting is carried out layer by layer from bottom to top. The ore produced by blasting is released to the mine exit tunnel, and then transported from the mine exit tunnel to the mining field chute and then to the middle transportation tunnel;

[0010] S4: Determine whether to retain the interlayer or blast treatment based on the proportion of the plastic zone of the interlayer and the thickness of the non-plastic zone after the mining of the a ore layer in the mine room; when retaining the interlayer, use tailings filling materials to fill the empty area formed by the mining of the a ore layer in the mine room; if blast treatment is used, while breaking and dropping the rock of the interlayer in the mine room, use tailings filling materials to fill the empty area formed by the a ore layer mine room and the interlayer;

[0011] S5: A large-diameter deep hole is constructed from the rock drilling chamber to the B ore layer. After charging, blasting is carried out layer by layer from bottom to top. The ore produced by the blasting is released to the mine exit tunnel, and then transported from the mine exit tunnel to the mine chute and then to the middle transport tunnel;

[0012] S6: Use tailings filling materials to fill the empty area created by mining the b ore layer;

[0013] S7: Drill holes for blasting from the rock drilling chamber to the a and b ore layers in the bottom pillar of the middle section. After charging, blast each layer from bottom to top. The ore produced by the blasting is transported to the auxiliary transport tunnel through the rock drilling tunnel.

[0014] Preferably, while performing steps S3-S6, for each ore block, a through-vein tunnel is horizontally constructed from the middle transport tunnel to the middle return air tunnel, and a drilling chamber is constructed along the strike of the through-vein tunnel in the a and b ore layers.

[0015] Preferably, in step S4, when the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold and the thickness of the non-plastic zone is greater than the second threshold, the interlayer is retained; when the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold and the thickness of the non-plastic zone is less than the second threshold, tailings filling materials are used to fill the empty areas produced by mining the a ore layer and the mine room, and grouting drilling and grouting are constructed between the tailings filling body and the interlayer to reinforce the plastic zone of the interlayer.

[0016] Preferably, in step S4, when the ratio of the thickness of the plastic zone to the thickness of the interlayer is greater than the first threshold and the thickness of the non-plastic zone is greater than the second threshold, tailings filling materials are used to fill the empty areas produced by mining the a ore layer and ore room, and grouting drilling and grouting are constructed between the tailings filling body and the interlayer to reinforce the plastic zone of the interlayer; if the thickness of the non-plastic zone is greater than the third threshold, only tailings filling materials are used to fill the empty areas produced by mining the a ore layer.

[0017] Preferably, in step S4, when the ratio of the plastic zone thickness to the interlayer thickness is greater than the first threshold and the non-plastic zone thickness is less than the second threshold, the interlayer in the mine room is broken and rock is removed while the tailings filling material is used to fill the a mine layer mine room and the empty area formed by the interlayer.

[0018] Preferably, in steps S4 and S6, when the tailings filling material is used to fill the mine room, the ratio of the binder to the tailings in the tailings filling material is: 1:4 in the lower part and 1:6-1:10 in the upper part.

[0019] Preferably, in step S7, if the thickness of the plastic zone of the interlayer formed after the mining of the ore layers on both sides is greater than the fourth threshold and the thickness of the non-plastic zone is greater than the fifth threshold, the interlayer is retained; if the thickness of the plastic zone of the interlayer formed after the mining of the ore layers on both sides is less than the fourth threshold and the thickness of the non-plastic zone is greater than the sixth threshold, the interlayer is retained; otherwise, the interlayer is blasted together with the ore layer, and the interlayer is not transported out when the mine is unloaded.

[0020] Preferably, each ore block is constructed sequentially along the strike direction or each ore block is constructed at intervals.

[0021] Preferably, the mine connection tunnel, the middle transport tunnel and the auxiliary transport tunnel are air intake tunnels.

[0022] Preferably, the auxiliary transport tunnel is used as the transportation path for the tailings filling material, and later the upper middle section bottom pillar is mined as the ore transportation path.

[0023] Beneficial technical effects: 1. The present invention determines the mining order of the ore layers based on the strength of the ore layers for nearly vertical ore layers, and first mines the ore layers with lower ore layer strength, which is conducive to mining and can reduce the disturbance to the interlayer. Then, the treatment method of the interlayer is determined based on the thickness of the interlayer and the influence of the mining of the ore layer, so as to ensure that the interlayer has sufficient strength or directly deal with the hidden danger of the interlayer before mining another ore layer, so as to prevent the interlayer from being unstable and damaged when mining another ore layer with greater strength, causing danger and a large amount of ore gangue.

[0024] 2. In the present invention, since the upper and lower parts of the bottom pillar are both tailings filling bodies when the upper middle bottom pillar is mined, there is no need to fill the empty area formed by the bottom pillar mining, thereby reducing the filling process and filling materials, reducing the filling cost, reducing the construction process, and improving the mining efficiency. The present invention can realize the full mining of the ore layer without leaving the top pillar, and the bottom pillar is not filled and recovered, the ore recovery rate is close to 100%, and can produce good economic benefits.

[0025] 3. The present invention adopts a three-in-three-out air intake method, and the air intake tunnel includes a mine outlet connecting tunnel, a middle transport tunnel, and an auxiliary transport tunnel, which can ensure the workers' breathing health and reduce the harm of mine dust to the workers' health. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the inclined cross section when mining the a ore layer in the open-pit subsequent filling mining method of the present invention;

[0027] Figure 2 It is a schematic diagram of the inclined profile when mining the b ore layer in the open-pit subsequent filling mining method of the present invention;

[0028] Figure 3 It is a schematic diagram of the inclined cross section during bottom pillar mining in the open field and subsequent filling mining method of the present invention;

[0029] In the figure, there is a middle transport tunnel 1, a mining chute 2, a ore-rock boundary 3, a blasthole 4, a bottom pillar 5, an upper middle transport tunnel (auxiliary transport tunnel) 6, a return air skylight 7, a middle return air tunnel 81, a mine return air tunnel 82, an upper middle return air tunnel (rock drilling return air tunnel) 83; an interlayer 9; ore 10; an upper middle through-vein tunnel (rock drilling tunnel) 11; a rock drilling chamber 12; a tailings filling body 13; a through-vein tunnel 14; a mine tunnel 15; a mine connecting tunnel 16; and a mine room 17. DETAILED DESCRIPTION

[0030] The following is combined with Figure 1-3 The present invention is further described based on the middle section 1060 of Datang Mine Section of Wengfu Phosphate Mine.

[0031] The geological conditions of the middle section 1060 of the Datang mining section of Wengfu Phosphate Mine and its upper and lower middle sections are basically the same. The ore layers include a ore layer and b ore layer with a dip angle of 85° and thicknesses of approximately 12m and 18m respectively. The thickness of the interlayer 9 between the two ore layers is approximately 3m. The roof, interlayer and floor are all dolomite. The rock strength coefficients f of the roof, b ore layer, interlayer, a ore layer and floor are 14.37, 12.45, 7.29, 8.44 and 9.86 respectively.

[0032] Based on the thickness and strength of the two ore layers, the strength and thickness of the interlayer 9, the present invention proposes a mining sequence of first mining the a ore layer and then mining the b ore layer, as well as a technical solution for retaining the interlayer; at the same time, no top pillar is set, only bottom pillar is set, and the bottom pillar of the previous middle section (such as the 1130 middle section) is used as the top pillar of the next middle section (such as the 1060 middle section), and the bottom pillar of the previous middle section (such as the 1130 middle section) and the mine room of the next middle section (such as the 1060 middle section) are mined at the same time. Specifically, the staged empty field and subsequent filling mining method of the phosphate ore bed bottom pillar and ore block coordinated by the present invention includes the following steps:

[0033] S1: Figure 1 As shown, within the scope of this middle section (1060 middle section, the lowest elevation of this middle section is 1060m), the ore layer is divided into several blocks along the strike of the ore layer, the length of each block along the strike is 15-20m, and it is recommended to set the length of the block along the strike in the manner of 15m and 20m intervals; for each block, it is divided into a mine room 17 and a bottom pillar 5 along the height direction, the vertical height of the mine room 17 is 55m, the vertical height of the bottom pillar 5 is 15m, that is, the vertical height of the ore block is 70m, and the thickness of the ore block is the total thickness of the ore layer and the interlayer; the upper part of the mine room 17 is the mine room of the ore block of the previous middle section (1130 middle section, the lowest elevation of this middle section is 1130m), and the bottom pillar 5 left after mining and filling is adopted by the staged open field and subsequent filling mining method;

[0034] S2: Figure 1 As shown, a middle section transport tunnel 1 is constructed at the bottom of the roof side of the middle section bottom pillar 5 along the direction of the ore layer, and the elevation of the middle section transport tunnel 1 is consistent with the elevation of the bottom of the middle section bottom pillar 5; in the upper part of the middle section transport tunnel 1, a mine connection tunnel 16 is constructed at the bottom of the roof side of the middle section mine room 17 along the direction of the ore layer;

[0035] A middle section return air lane 81 is constructed at the bottom of the bottom plate side of the middle section bottom pillar 5 along the direction of the ore layer, and the elevation of the middle section return air lane 81 is consistent with the elevation of the bottom of the middle section bottom pillar 5; in the upper part of the middle section return air lane 81, a mine return air lane 82 is constructed at the bottom of the bottom plate side of the middle section mine room 17 along the direction of the ore layer;

[0036] An upper middle section transport tunnel 6 is left on the top plate side of the bottom pillar 5 of the upper middle section, serving as the auxiliary transport tunnel 6 of the current middle section; an upper middle section return air tunnel 83 is left on the bottom plate side of the bottom pillar 5 of the upper middle section, serving as the rock drilling return air tunnel 83 of the current middle section; in each ore block of the upper middle section, an upper middle section through-vein tunnel 11 is horizontally constructed to connect the upper middle section transport tunnel 6 and the upper middle section return air tunnel 83, serving as the current middle section rock drilling tunnel 11 to connect the current middle section auxiliary transport tunnel 6 and the current middle section rock drilling return air tunnel 83; rock drilling chambers 12 are also constructed along the strike in the a ore layer and the b ore layer of each ore block;

[0037] Extend the return air shaft 7 to the bottom of the middle section, and construct a horizontal tunnel to connect the return air shaft 7 with the rock drilling return air lane 83, the mine return air lane 82, and the middle section return air lane 81;

[0038] In this middle section, for each ore block, a mine tunnel 15 is horizontally constructed from the mine connection tunnel 16 to the mine return air tunnel 82, and a stope chute 2 is horizontally constructed from the side of the mine connection tunnel 16 away from the ore layer to connect to the middle transport tunnel 1;

[0039] S3: Figure 1 As shown, by comparing the rock formation firmness coefficients of the a ore layer and the b ore layer, the ore layer with a smaller rock formation firmness coefficient is mined first; in this embodiment, the rock formation firmness coefficients f of the b ore layer and the a ore layer are 12.45 and 8.44 respectively, so the a ore layer is mined first; a large-diameter deep hole 4 is constructed from the rock drilling chamber 12 to the a ore layer in the mine room, and after charging, blasting is performed layer by layer from bottom to top, and the ore 10 produced by the blasting is released from the ore discharge funnel to the ore discharge tunnel 15, and then transported from the ore discharge tunnel 15 to the stope chute 2 and then to the middle transport tunnel 1, and transported out through the transportation equipment of the middle transport tunnel 1;

[0040] S4: Figure 2 As shown, the ratio of the thickness of the plastic zone of the interlayer 9 to the thickness of the interlayer after the mining of the a ore layer in the mine room, as well as the thickness of the non-plastic zone of the interlayer are determined. When the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold value (set to 40% in this embodiment) and the thickness of the non-plastic zone is greater than the second threshold value (set to 1.2m in this embodiment), the interlayer does not need to take reinforcement measures and is retained, indicating that the thickness of the interlayer is large enough and the strength is high;

[0041] When the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold value (set to 40% in this embodiment) and the thickness of the non-plastic zone is less than the second threshold value (set to 1.2 m in this embodiment), the tailings filling material is used to fill the empty area produced by the mining of the a ore layer and the grouting drilling and grouting reinforcement of the interlayer plastic zone are constructed between the tailings filling body 13 and the interlayer 9, indicating that the interlayer thickness is small but the strength is very high;

[0042] When the ratio of the thickness of the plastic zone to the thickness of the interlayer is greater than the first threshold value (set to 40% in this embodiment) and the thickness of the non-plastic zone is greater than the second threshold value (set to 1.2m in this embodiment), the tailings filling material is used to fill the empty area generated by the mining of the a ore layer and the mine room, and the grouting drilling and grouting reinforcement of the interlayer plastic zone are constructed between the tailings filling body 13 and the interlayer 9, indicating that the interlayer thickness is moderate but the strength is weak. If the thickness of the non-plastic zone is greater than the third threshold value (set to 3.5m in this embodiment), only the tailings filling material can be used to fill the empty area generated by the mining of the a ore layer and the mine room, and there is no need to construct grouting drilling and grouting reinforcement of the interlayer plastic zone, indicating that the interlayer thickness is large but the strength is weak.

[0043] When the ratio of the plastic zone thickness to the interlayer thickness is greater than the first threshold value (set to 40% in this embodiment) and the non-plastic zone thickness is less than the second threshold value (set to 1.2 m in this embodiment), the interlayer 9 in the mine room is broken and rock is removed while the tailings filling material is used to fill the mine room of the a ore layer and the empty area formed by the interlayer, indicating that the interlayer thickness is small and the strength is weak;

[0044] In this embodiment, the thickness of the interlayer 9 is 3m on average. Since the strength of the interlayer is only slightly less than that of the a ore layer, the mining of the a ore layer has little disturbance on the interlayer, and the plastic zone accounts for about 20%. The thickness of the interlayer is moderate, and the thickness of the non-plastic zone is about 2.4m. Therefore, in this embodiment, tailings filling materials are used to fill the empty area generated by the mining of the a ore layer, and then grouting drilling and grouting are constructed between the tailings filling body 13 and the interlayer 9 to reinforce the plastic zone of the interlayer;

[0045] In this embodiment, tailings filling materials are used to fill the empty areas produced by mining of the a ore layer (and rock breaking and rock falling of the interlayer) in the mine room. The ratio of binder (such as cement) to tailings in the tailings filling materials is 1:4 in the lower part (vertical height 15m) and 1:6-1:10 in the upper part (vertical height 15m);

[0046] The present invention aims at nearly vertical ore layers, determines the mining order of the ore layers based on the strength of the ore layers, and mines the ore layers with lower strength first, which is beneficial to mining and can reduce the disturbance to the interlayers; then, based on the thickness of the interlayers and the influence of the mining of the ore layers (the proportion of the plastic zone), determines the treatment method of the interlayers to ensure that the interlayers have sufficient strength or directly treat the hidden danger of the interlayers before mining another ore layer, so as to prevent the interlayers from being unstable and damaged when mining another ore layer with greater strength, causing danger and a large amount of ore gangue.

[0047] S5: Figure 2 As shown, a large-diameter deep hole 4 is constructed from the rock drilling chamber 12 to the b ore layer. After charging, blasting is performed layer by layer from bottom to top. The ore 10 produced by the blasting is released from the ore discharge funnel to the ore discharge tunnel 15, and then transported from the ore discharge tunnel 15 to the mining field chute 2 and then to the middle transport tunnel 1, and then transported out through the transportation equipment of the middle transport tunnel 1;

[0048] S6: Figure 3 As shown, tailings filling materials are used to fill the empty areas created by mining of the b ore layer. The ratio of binder (such as cement) to tailings in the tailings filling materials is 1:4 in the lower part (vertical height 15m) and 1:6-1:10 in the upper part (vertical height 15m).

[0049] While carrying out steps S3-S6, for each ore block, a through-vein tunnel 14 is horizontally constructed from the middle transport tunnel 1 to the middle return air tunnel 81, and a rock drilling chamber 12 is constructed along the strike of the through-vein tunnel 14 in the a and b ore layers;

[0050] S7: Figure 3 As shown, blasting holes are constructed from the rock drilling chamber 12 to the a and b ore layers in the bottom pillar 5 in the upper middle section. After charging, blasting is carried out layer by layer from bottom to top. The ore 10 produced by the blasting is transported to the auxiliary transport tunnel 6 through the rock drilling tunnel 11 for transportation out.

[0051] In step S7, if the thickness of the plastic zone formed by the mining of the ore layers on both sides of the interlayer 9 is greater than the fourth threshold value (50% in this embodiment) and the thickness of the non-plastic zone is greater than 2m, the interlayer is retained, indicating that the interlayer strength is general but the thickness is large; if the thickness of the plastic zone formed by the mining of the ore layers on both sides of the interlayer 9 is less than the fourth threshold value (50% in this embodiment) and the thickness of the non-plastic zone is greater than 1.2m, the interlayer is retained, indicating that the interlayer strength is large and the thickness is moderate; otherwise, the interlayer is blasted together with the ore layer, and the interlayer is not transported out when the mine is removed. In this embodiment, it is estimated that the plastic zone of the interlayer caused by the mining of the ore layers on both sides accounts for 40%. Since the height of the bottom pillar is relatively small, the influence of the mining of the ore layers is small, the plastic zone range is small, the integrity is good, and the thickness of the non-plastic zone reaches 1.8m, so the interlayer 9 can be retained.

[0052] In the present invention, since the upper and lower parts of the bottom pillars are both tailings filling bodies when the last middle section bottom pillar is mined, there is no need to fill the empty area formed by the bottom pillar mining, because when the mining and filling work of the current middle section mine room is carried out, the upper part of the bottom pillar of the previous middle section is the tailings filling body produced by the mining of the mine room, and the proportion of the cementing material used is large, which ensures the strength of the tailings filling body, and can avoid the influence of the empty area after the mining of the last middle section bottom pillar during the mining of the current middle section bottom pillar, especially the mine room height of the present invention reaches 55m. In this way, the present invention can reduce the filling process and filling materials, reduce the filling cost, reduce the construction process, and improve the mining efficiency. The present invention can realize the full mining of the ore layer, without leaving the top pillar, and the bottom pillar is not filled and recovered, the ore recovery rate is close to 100%, and good economic benefits can be generated.

[0053] In the present invention, each ore block in the middle section and the bottom pillar of the corresponding upper middle section are constructed in sequence along the strike direction, or the odd-numbered ore blocks are constructed first and then the even-numbered ore blocks.

[0054] In the present invention, during the process of dropping and transporting each ore block, the air intake path is: the mine connection tunnel 16, the mine tunnel 15, the mine return air tunnel 82, and the return air skylight 7; the mine dust generated by the blasting of the mine room is large, and there are many miners, but ventilation through the mine connection tunnel 16 can ensure the freshness of the wind and reduce the impact of the mine dust generated during ore transportation; because the ore is transported out through the mining field chute 2 through the middle transportation tunnel 1, and the mining field chute 2 is located on the side of the mine connection tunnel 16 away from the ore layer, the wind entering from the mine connection tunnel 16 is less affected by ore transportation, which can improve the quality of the wind in the mine tunnel 15 and ensure the health of the workers.

[0055] In the present invention, when the middle section vein tunnel 14 and rock drilling chamber 12 are under construction, the air inlet path is: middle section transport tunnel 1, vein tunnel 14, middle section return air tunnel 81, return air shaft 7; although a certain amount of ore dust will be generated due to ore transportation, the impact is small due to the small number of staff.

[0056] In the present invention, during the process of dropping and filling of each ore block, the air inlet path is: auxiliary transport tunnel 6, rock drilling tunnel 11, rock drilling return air tunnel 83, return air skylight 7; the auxiliary transport tunnel 6 is used as the transportation path for tailings filling materials and as the transportation path for auxiliary materials for construction. In the later stage, the upper middle bottom pillar recovery is used as the ore transportation path (auxiliary transportation equipment can be used for transportation). The specific filling path is: auxiliary transport tunnel 6, rock drilling tunnel 11 and rock drilling chamber 12, rock drilling return air tunnel 83, return air skylight 7; the specific ore transportation path is: rock drilling tunnel 11, auxiliary transport tunnel 6.

[0057] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone can derive other various forms of methods under the inspiration of the present invention. Any technical solution that is the same or similar to that of the present application falls within the protection scope of the present invention.

Claims

1. A staged empty field and subsequent filling mining method with coordinated bottom pillars and ore blocks of phosphate ore beds, characterized in that: The steps include: S1: In this middle section, the ore layer is divided into several blocks along the ore layer direction; for each block, it is divided into a mine room and a bottom pillar along the height direction, and the thickness of the block is the total thickness of the ore layer and the interlayer; the upper part of the mine room is the bottom pillar left after the mine room of the previous middle section ore block is filled; S2: construct the middle section transport tunnel at the bottom of the middle section bottom pillar roof side along the ore seam direction, and construct the mine connection tunnel at the bottom of the middle section mine room roof side along the ore seam direction; construct the middle section return air tunnel at the bottom of the middle section bottom pillar bottom side along the ore seam direction, and construct the mine return air tunnel at the bottom of the middle section mine room bottom side along the ore seam direction; An upper middle section transport lane is left on the top plate side of the bottom pillar of the upper middle section as the auxiliary transport lane of this middle section; an upper middle section return air lane is left on the bottom plate side of the bottom pillar of the upper middle section as the rock drilling return air lane of this middle section; in each ore block of the upper middle section, an upper middle section through-vein lane is horizontally constructed to connect the upper middle section transport lane and the upper middle section return air lane, which serves as the rock drilling lane of this middle section; rock drilling chambers are constructed along the strike in the a ore layer and the b ore layer of each ore block; Extend the return air shaft to the bottom of this middle section, construct a horizontal tunnel to connect the return air shaft with the rock drilling return air tunnel, the mine return air tunnel, and the middle section return air tunnel; in this middle section, for each ore block, construct a mine roadway from the mine connection tunnel to the mine return air tunnel, and construct a stope chute from the side of the mine connection tunnel away from the ore layer to connect the middle section transport tunnel; S3: First, the a ore layer with a smaller rock solidity coefficient is mined, and a large-diameter deep hole is constructed from the rock drilling chamber to the a ore layer in the mine room. After charging, blasting is carried out layer by layer from bottom to top. The ore produced by blasting is released to the mine exit tunnel, and then transported from the mine exit tunnel to the mining field chute and then to the middle transportation tunnel; S4: Determine whether to retain the interlayer or blast treatment based on the proportion of the plastic zone of the interlayer and the thickness of the non-plastic zone after the mining of the a ore layer in the mine room; when retaining the interlayer, use tailings filling materials to fill the empty area formed by the mining of the a ore layer in the mine room; if blast treatment is used, while breaking and dropping the rock of the interlayer in the mine room, use tailings filling materials to fill the empty area formed by the a ore layer mine room and the interlayer; S5: A large-diameter deep hole is constructed from the rock drilling chamber to the B ore layer. After charging, blasting is carried out layer by layer from bottom to top. The ore produced by the blasting is released to the mine exit tunnel, and then transported from the mine exit tunnel to the mine chute and then to the middle transport tunnel; S6: Use tailings filling materials to fill the empty area created by mining the b ore layer; S7: Drill holes for blasting from the rock drilling chamber to the a and b ore layers in the bottom pillar of the middle section. After charging, blast each layer from bottom to top. The ore produced by the blasting is transported to the auxiliary transport tunnel through the rock drilling tunnel.

2. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: While carrying out steps S3-S6, for each ore block, a through-vein tunnel is horizontally constructed from the middle transport tunnel to the middle return air tunnel, and a drilling chamber is constructed along the strike of the through-vein tunnel in the a and b ore layers.

3. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: In step S4, when the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold and the thickness of the non-plastic zone is greater than the second threshold, the interlayer is retained; when the ratio of the thickness of the plastic zone to the thickness of the interlayer is less than the first threshold and the thickness of the non-plastic zone is less than the second threshold, tailings filling materials are used to fill the empty area generated by the mining of the a ore layer and the mine room, and grouting drilling and grouting are constructed between the tailings filling body and the interlayer to reinforce the plastic zone of the interlayer.

4. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: In step S4, when the ratio of the thickness of the plastic zone to the thickness of the interlayer is greater than the first threshold and the thickness of the non-plastic zone is greater than the second threshold, tailings filling materials are used to fill the empty areas produced by the mining of the a ore layer and the mine room, and grouting drilling and grouting are constructed between the tailings filling body and the interlayer to reinforce the plastic zone of the interlayer. If the thickness of the non-plastic zone is greater than the third threshold, only tailings filling materials are used to fill the empty areas produced by the mining of the a ore layer.

5. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: In step S4, when the ratio of the plastic zone thickness to the interlayer thickness is greater than the first threshold and the non-plastic zone thickness is less than the second threshold, the interlayer in the mine room is broken and rock is removed while the tailings filling material is used to fill the empty area formed by the mine room and the interlayer of the a ore layer.

6. The staged emptying and subsequent filling mining method according to any one of claims 1 to 5, characterized in that: In steps S4 and S6, when the tailings filling material is used to fill the mine room, the ratio of the binder to the tailings in the tailings filling material is: 1:4 in the lower part and 1:6-1:10 in the upper part.

7. The staged emptying and subsequent filling mining method according to any one of claims 1 to 5, characterized in that: In step S7, if the thickness of the plastic zone of the interlayer formed after the mining of the ore layers on both sides is greater than the fourth threshold and the thickness of the non-plastic zone is greater than the fifth threshold, the interlayer will be retained; if the thickness of the plastic zone of the interlayer formed after the mining of the ore layers on both sides is less than the fourth threshold and the thickness of the non-plastic zone is greater than the sixth threshold, the interlayer will be retained; otherwise, the interlayer will be blasted together with the ore layer, and the interlayer will not be transported out when the mine is unloaded.

8. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: Each ore block is constructed sequentially along the strike direction or each ore block is constructed at intervals.

9. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: The mine connecting tunnel, middle transport tunnel and auxiliary transport tunnel are air intake tunnels.

10. The staged emptying and subsequent filling mining method according to claim 1 is characterized in that: The auxiliary transport tunnel is used as the transportation path for tailings filling materials, and later the upper middle section bottom pillar is mined as the ore transportation path.

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