Horizontal short-hole shrinkage method suitable for residual phosphate ore mining

Abstract

The application discloses a horizontal shallow hole and ore remaining room pillar method suitable for phosphorite residual ore mining, which comprises the following steps: firstly, designing middle section and stope structure parameters, determining the position of the ore pillar, then performing preparation and cutting engineering, and finally, in the process of the last mining, after rock drilling and blasting, ventilation and ore leveling, a working face for subsequent mining is formed, then in the subsequent mining, with the increase of the stripped ore and the expansion of the mined-out area, three continuous working zones of mining, ore transportation and dry filling are formed between two ore pillar mining areas, and the mining is repeatedly performed. In order to cope with the complex engineering environment of the phosphorite, for the area with poor operation conditions, a door-shaped arch pillar is used between the ore pillars to improve the stability of the mined-out area. The application can improve the residual ore mining efficiency of the lower layer existing mined-out area, is safe and reliable in mining operation, low in production cost, small in engineering quantity, high in adaptability to engineering environment, and can fully utilize the ore pillar condition of the mined-out area to meet the supporting requirement.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mining methods of mines, and particularly relates to a horizontal shallow hole ore-remaining room pillar method suitable for residual phosphate ore recovery. BACKGROUND

[0002] When mining such a gently inclined ore body as phosphate ore, the shallow hole room pillar method is often used for recovery under the condition that the filling mining technology cost is high. Generally, the phosphate ore is mined from the lower phosphate layer (Ph1) to the middle phosphate layer (Ph2) and the upper phosphate layer (Ph3) in turn. Due to the constraints of occurrence conditions, rock drilling, ore extraction, support and other aspects, it is difficult to realize safe, efficient and economic mining of this type of ore body. At the same time, due to the limitation of roof management and support, only the lower phosphate ore (Ph1) with high grade is often recovered, and the ore is not completely mined, resulting in a waste of a large amount of valuable mineral resources. How to efficiently and safely recover the residual ore body under the complex goaf has important practical significance for the full use of mineral resources of mining enterprises and the extension of the service life of mines. The research and practice of residual ore recovery are also increasingly concerned by people.

[0003] For this type of gently inclined phosphate ore residual ore body with a goaf in the lower part, the conventional mining method and the existing technical level have poor safety in recovery operation, great difficulty in recovery, and poor effect in residual ore recovery. It is imperative to explore a low-consumption, safe and efficient recovery method for the residual ore layer under the complex goaf.

[0004] Therefore, it is urgent to research a horizontal shallow hole ore-remaining room pillar method suitable for residual phosphate ore recovery to meet the above needs. SUMMARY

[0005] For the problem of mining the gently inclined phosphate ore residual ore with a goaf in the lower part, the application provides a horizontal shallow hole ore-remaining room pillar method suitable for residual phosphate ore recovery, which can effectively solve the problems of poor safety in recovery operation, low recovery efficiency and great difficulty in recovery of this type of ore body.

[0006] Based on the above problems, the application adopts the following technical scheme:

[0007] A horizontal shallow hole ore-remaining room pillar method suitable for residual phosphate ore recovery, characterized in that the specific steps are as follows:

[0008] Step S1. Determine the structure parameters of the stope:

[0009] Determine the size of the ore room and preset the position of the ore pillar according to the mine output and technical conditions, and a "door" type ore pillar is left between two adjacent ore pillars in the region with unstable engineering environment;

[0010] Step S2. Preparation and cutting:

[0011] A pedestrian ventilation connecting passage is excavated along the middle section transportation roadway to the ore body, the roadway is developed to the goaf through the pedestrian ventilation connecting passage, a cutting slot is developed upward at the end above the ore room, a cutting raise is formed horizontally and penetrates the phosphate ore layer, after the ore drawing and transportation process is completed, a top cutting layer drilling flat roadway is developed gradually, and a drilling flat roadway is arranged at a certain distance from the bottom to the top along the inclination direction;

[0012] Step S3. Stoping;

[0013] (1) Stoping sequence

[0014] In the strike direction, the mining is from both ends to the middle, and in the inclination direction, the mining is from top to bottom;

[0015] (2) Drilling and blasting

[0016] After the cutting slot construction is completed, as the most initial blasting free space, horizontal blast holes are arranged at the cutting slot along the strike direction of the ore body for blasting, after the horizontal blast holes are arranged for the mined ore body at the cutting slot, blasting is performed, for the multi-layer deposition ore layer of the phosphate ore, the blasting is performed along the strike direction, and the blasting is performed from bottom to top along the ore layer, and the lower ore layer mining is ahead of the upper ore layer;

[0017] (3) Ventilation

[0018] After the blasting operation, the blasting gas discharge work is performed;

[0019] (4) Leveling the ore

[0020] Step S4. The above steps 2-3 are repeated, and the ore accumulation forms an original operation space;

[0021] Step S5. Ore transportation;

[0022] Step S6. Dry filling

[0023] Step S7.

[0024] According to the stoping structure parameters calculated in step S1, the ore pillars are reserved, the maximum span between the stoping filling operation surface and the blasting operation surface is determined, and steps S3 to S6 are repeated.

[0025] Further, in step S1, for the region with complex engineering environment, the part of the ore body between the ore pillars of the two ore layers at the upper part of the goaf is not mined as the roof, and the original ore pillar of the goaf is used as support, thereby forming a door-shaped ore pillar with a door-shaped appearance.

[0026] Further, the roof thickness of the door-shaped ore pillar ranges from 10-10.5m.

[0027] Further, the width of the top cutting layer drilling flat roadway is 2-3m.

[0028] Further, the blasting in step S3 is for the upward mining sequence due to the existence of the lower goaf, by taking the original goaf as the working face, developing the cutting groove to the top, then blasting the horizontal fan-shaped holes along the strike direction in the cutting groove, cutting the groove as the compensation space for horizontal short-hole blasting, taking the blasting ore pile as the working platform, continuing to develop the cutting groove upward, gradually increasing the cutting groove height, then blasting the holes horizontally, and finally large-scale continuous mining.

[0029] Further, in step S6, the dry filling is specifically using the waste rock or waste rock yard stone of the mined section to fill, and covering the concrete to reinforce the filling area.

[0030] Further, in step S7, steps S3 to S6 are repeated, and three stage areas are gradually formed in the panel to work continuously, which are the dry filling area, the ore transportation area, and the mining and ore falling area along the recovery direction.

[0031] Compared with the prior art, the present application has the following beneficial effects:

[0032] 1. The horizontal short-hole blasting after the cutting groove is cut by the horizontal short-hole and ore-remaining room-and-pillar method can make the blasting pile more concentrated, greatly reduce the range of ore scattering, and improve the safety of blasting.

[0033] 2. The horizontal short-hole and ore-remaining room-and-pillar method combines the advantages of the ore-remaining method and the room-and-pillar method, uses the short-hole for recovery, is flexible, helps to remove the stone and control the dilution rate, and ensures the recovery rate.

[0034] 3. The horizontal short-hole and ore-remaining room-and-pillar method can combine the complex engineering environment, fully utilize the pillar conditions of the goaf, adopt the door-type arch pillar design for the places with unstable geological conditions to improve the safety of the goaf operation, and make the mine room and pillar penetrate the ore layer for the places with stable geological conditions to improve the recovery rate of the pillar. BRIEF DESCRIPTION OF DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following describes the drawings needed in the prior art description as a simple introduction. Obviously, for those skilled in the art, other drawings can be obtained without creative labor based on these drawings.

[0036] Figure 1 A mine room plan view of the horizontal short-hole and ore-remaining room-and-pillar method suitable for phosphate ore residual mining according to the present application;

[0037] Figure 2It is a mine room longitudinal section view of a horizontal shallow hole ore room pillar method suitable for residual ore recovery of phosphate ore according to the patent;

[0038] Figure 3 It is a mine room transverse section view of a horizontal shallow hole ore room pillar method suitable for residual ore recovery of phosphate ore according to the patent;

[0039] Figure 4 It is a mine room longitudinal section view of a horizontal shallow hole ore room pillar method suitable for residual ore recovery of phosphate ore according to the patent;

[0040] Figure 5 It is a partial mine room recovery schematic view of a horizontal shallow hole ore room pillar method suitable for residual ore recovery of phosphate ore according to the patent;

[0041] Reference signs:

[0042] 1 - middle section transportation roadway, 2 - lower sublevel transportation ramp, 3 - door-shaped arch pillar, 4 - top cutting layer transportation ramp, 5 - pedestrian ventilation connecting tunnel, 6 - top cutting layer drilling roadway, 7 - cutting groove, 8 - cutting raise, 9 - stable pillar, 10 - weak pillar, 11 - vertical medium-depth blast hole, 12 - horizontal fan-shaped blast hole, 13 - first stage area, 14 - second stage area, 15 - third stage area. DETAILED DESCRIPTION

[0043] The technical solutions in the patent embodiments of the present application will be clearly and completely described below with reference to the drawings in the patent embodiments of the present application. Obviously, the described embodiments are only some of the patent embodiments of the present application, not all.

[0044] Embodiment one

[0045] Figures 1 to 3 As shown, the selected phosphate ore body in Hubei is a gently inclined ore body, and the overall mining method has been adopted since the mine was built. The middle-high grade area of the lower phosphorus layer (Ph1) in the mining area is mined, which accounts for about one fourth of the entire thickness, causing great resource waste and environmental damage. Now the residual ore in the upper goaf is recovered.

[0046] The patent provides a horizontal shallow hole ore room pillar method suitable for residual ore recovery of phosphate ore, which comprises the following steps:

[0047] Step S1. Determine the structure parameters of the stope;

[0048] The size of the room is determined according to the mine production and technical conditions, and the pillar position is preset. For the area with unstable engineering environment, a "door" type pillar is left between two adjacent pillars. In this embodiment, the pillar position along the strike and dip direction of the room is aligned with the lower goaf pillar. During the mining process, the area without preset pillars is mined from top to bottom along the strike in sequence, and then gradually blasted to form a room. After that, the ore body between the pillars is mined.

[0049] Step S2. Preparation and cutting;

[0050] A pedestrian ventilation connecting tunnel 5 is excavated along the middle section transportation roadway 1 to the ore body. The roadway is developed through the pedestrian ventilation connecting tunnel 5 to reach the room. A cutting slot 7 is developed upward at the end above the room. A cutting slot 8 is gradually formed through the phosphate ore layer to provide space and engineering conditions for subsequent mining. A top cutting rock drilling roadway 6 is developed along the strike, with a width of about 2-3 m. A top cutting rock drilling roadway 6 is arranged every 19.5 m along the dip direction according to the mining sequence to provide a free surface and a transportation channel for subsequent ore body mining.

[0051] Step S2. Preparation and cutting:

[0052] Step S3. Mining

[0053] (1) Mining sequence

[0054] Mining from both ends to the middle in the strike direction, and from top to bottom in the dip direction;

[0055] (2) Rock drilling and blasting

[0056] As shown in Figure 4 , vertical medium-depth blast holes 11 are arranged at the lower phosphate ore (Ph1) end. After blasting, a cutting slot 7 is formed. After the cutting slot 7 is constructed, it serves as the initial blasting free space. After arranging horizontal fan-shaped blast holes 12 for the mined ore body at the cutting slot 7, blasting is performed. For multiple layers of phosphate ore deposits, forward blasting is performed along the strike, and blasting is performed from bottom to top along the ore layer. The lower ore layer mining should be ahead of the upper ore layer.

[0057] (3) Ventilation

[0058] After blasting, the blasting gas discharge work is performed.

[0059] (4) Leveling the ore

[0060] The fallen ore is accumulated in the stope by gravity and temporarily left in the room, so that the ore pile surface maintains a working space of about 2 m high between the working face. The ore pile surface is leveled by manpower or machinery, and the ore continues to fall until the room mining is completed.

[0061] Step S4. Repeat the above steps 2-3 times, and the ore is accumulated to form the original working space;

[0062] Step S5. Ore transportation

[0063] When the panel length of the ore falling area reaches a certain length, the ore is transported from the previous ore falling area, the shovel reaches the mine from the top cutting layer transportation ramp 6, enters the ore falling area through the top cutting layer drilling roadway 6, and reaches the middle section transportation roadway from the goaf through the top cutting layer transportation ramp 4, and then is transported to the ground surface through the main transportation ramp.

[0064] Step S6. Dry filling step

[0065] When the panel length of the ore falling area reaches a certain length, the ore is transported from the previous ore falling area, the shovel reaches the mine from the top cutting layer transportation ramp 6, enters the ore falling area through the top cutting layer drilling roadway 6, and reaches the middle section transportation roadway from the goaf through the top cutting layer transportation ramp 4, and then is transported to the ground surface through the main transportation ramp.

[0066] Step S7. The stope structure parameters calculated in step S1 are reserved, and the maximum span between the stope filling working face and the blasting working face is determined, and steps three to six are repeated, so that the goaf mining, ore transportation, and filling operations in the same panel can be carried out simultaneously. That is, the first stage area 13 in the above figure corresponds to the mining and ore falling area, the second stage area 14 corresponds to the ore transportation area, and the third stage area 15 corresponds to the dry filling area. Figure 5

[0067] In a further preferred embodiment, for the area with complex engineering environment, the part of the ore body between the pillars of the upper two ore layers of the goaf is not mined as the roof, and a portal pillar is formed, and the original pillar of the goaf is used as support, thereby forming a portal pillar with a portal shape, a thick roof, and good stability. In this embodiment, the roof thickness of the portal pillar is in the range of 10-10.5m, and the Flac 3D and other related software are used to conduct numerical simulation analysis to verify the feasibility of the design in maintaining the stability of the goaf. The portal pillar is installed according to the complex engineering environment to protect the area with weak stability.

[0068] In a further preferred embodiment, the rock drilling and blasting in step S3 is carried out according to the upward mining sequence due to the existence of the goaf below. The original goaf is used as the working face, the cutting slot is cut upward, then horizontal fan-shaped blast holes are drilled along the strike direction in the cutting slot, horizontal shallow hole blasting is carried out with the cutting slot as the compensation space, the blasting ore pile is used as the working platform, the cutting slot is gradually raised, the drilling height is gradually increased, then horizontal drilling and blasting are carried out, and finally large-scale continuous mining is carried out.

[0069] ​The dry filling in step S6 can be filled with waste rock or waste rock yard stone of the mined section level, which has high strength, low cost and can be reused, and the concrete reinforced filling area is covered.

[0070] The above description is only a preferred embodiment of the present application, and the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacements or changes according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

[0071] The technical means disclosed in the present application is not limited to the technical means disclosed in the above embodiment, and also includes the technical scheme composed of any combination of the above technical features. It should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, some improvements and refinements can be made, which are also considered as the protection scope of the present application.

Claims

1. A horizontal shallow-hole ore-retention room pillar method suitable for mining residual phosphate ore, characterized in that: The specific steps are as follows: Step S1. Determine the stope structure parameters: The size of the stope and the location of the pillars are determined based on the mine's output and technical conditions. In areas with unstable engineering environments, a "gate"-shaped pillar is left between two adjacent pillars. In areas with complex engineering environments, part of the ore body between the pillars of the two ore layers above the goaf is used as the roof and is not mined. The original pillars of the goaf serve as support, thus forming a gate-shaped pillar. The thickness of the roof of the gate-shaped pillar ranges from 10 to 10.5 meters. Step S2. Precision sampling and cutting: A pedestrian ventilation connecting roadway is excavated along the middle section of the transport roadway toward the ore body. The roadway is then developed through the pedestrian ventilation connecting roadway to reach the goaf. At the end above the stope, a cutting groove is developed upwards, and a cutting riser is gradually formed horizontally to penetrate the phosphate ore layer. After the ore is dropped and transported, a cutting-top drilling roadway is gradually developed. A drilling roadway is laid out at regular intervals from bottom to top along the dip direction. Step S3. Re-mining; (1) Mining sequence In terms of direction, mining proceeds from both ends towards the middle; in terms of dip, mining proceeds from top to bottom. (2) Rock drilling and blasting After the cutting groove is constructed, as the initial free space for blasting, horizontal blast holes are arranged along the strike direction of the ore body at the cutting groove for blasting. Blasting is carried out after the horizontal blast holes are arranged at the ore body to be mined from the cutting groove. For multi-layer sedimentary phosphate ore, forward blasting is carried out along the strike, and blasting is carried out from bottom to top along the ore layer. The mining of the lower ore layer should be carried out ahead of the upper ore layer. For the bottom-up mining sequence adopted due to the existence of goaf in the lower part, the original goaf is used as the working face to open up the cutting groove to the top. Then, horizontal fan-shaped blast holes are drilled in the cutting groove along the strike direction. Horizontal shallow hole blasting is carried out with the cutting groove as the compensation space. The blasted ore pile is used as the working platform to continue to pull the groove upward, gradually increasing the groove height. Then, horizontal hole drilling and blasting are carried out. Finally, large-scale continuous ore extraction is carried out. (3) Ventilation After the blasting operation, the blasting gases are released. (4) Leveling the ore Step S4. Repeat steps 2 to 3 times above to accumulate ore and form the original working space; Step S5. Ore handling; Step S6. Dry filling Step S7. Based on the mining structure parameters calculated in step S1, reserve pillars and determine the maximum span between the mining filling face and the blasting face. Repeat steps S3 to S6.

2. The horizontal shallow-hole ore-retention room pillar method for mining residual phosphate ore as described in claim 1, characterized in that: The width of the rock-drilling tunnel for cutting the top layer is 2-3m.

3. The horizontal shallow-hole ore-retention room pillar method for mining residual phosphate ore as described in claim 1, characterized in that: In step S6, dry backfilling specifically involves reusing waste rock or waste rock dump material from the already mined section level for backfilling, and covering the backfill area with reinforced concrete.

4. The horizontal shallow-hole ore-retention room pillar method for mining residual phosphate ore as described in claim 1, characterized in that: In step S7, steps S3 to S6 are repeated, and three phase areas will gradually form in the panel area, which are working continuously and simultaneously. Along the mining direction, they are the dry filling area, the ore transportation area, and the mining and ore falling area.

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