A method for mining steeply inclined thin ore bodies in broken ground conditions

Abstract

The application discloses a kind of steeply inclined thin ore body mining method suitable for broken surrounding rock condition;It relates to underground mining technical field including following steps: S1, engineering geological condition investigation is carried out to ore body and its surrounding rock, and the structure parameters of stope are determined;S2, according to the length of stope, the ore body is divided into ore room and ore pillar along the trend, and is mined continuously in two steps;S3, construction of mining preparation cutting engineering in stope;S4, inclined ramp is arranged in the middle position of ore body at close range from ore body, and from inclined ramp to ore body, construction of communication roadway to the other side of ore body is carried out, then vertical communication roadway is close to the side of surrounding rock with better stability, and the mining access is constructed to both sides respectively, and step-by-step mining and filling are carried out;S5, after the first layer of mining is completed, filling is carried out, after filling is completed, the second layer of mining is carried out after reaching the design strength, and the cycle is carried out until the stope mining is completed;The application is provided with spiral inclined ramp and layered platform, so that the distance between inclined ramp and stope is reduced, the engineering quantity of communication roadway is greatly reduced, each layered platform is responsible for a layer, the slope of communication roadway is reduced, ore transportation and equipment operation are facilitated;Meanwhile, when steeply inclined thin ore body is mined in broken surrounding rock condition of upward horizontal layering, the problem that broken surrounding rock appears cross roof fall or even ore body roof appears cracking phenomenon, and the safety of personnel mining operation under cracked roof is poor is solved, and the application has the advantages of high safety, high efficiency, high mechanization rate and the like.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of underground mining, in particular to a mining method for steeply inclined thin ore body under broken surrounding rock condition. BACKGROUND

[0002] The steeply inclined thin ore body refers to the ore body with the inclination greater than 55° and the thickness less than 5m, which is commonly found in lead-zinc, gold, tungsten and other deposits, and the upward horizontal slicing and filling mining method is commonly used for mining such ore body. When the upward horizontal slicing and filling mining method is used for mining, the mining stope is generally arranged along the ore body strike, and the length of the mining stope is about 40.0-60.0m, especially when some independent ore body is mined, only one mining stope is arranged; the mining process is two mining and one filling, and the empty roof height is generally 6.0-8.0m. If the above mining method is used under the condition of broken surrounding rock, large area cross roof fall often occurs due to the large exposed area of the stope side, and even the roof cracking occurs, which causes great safety hazard. SUMMARY

[0003] In order to reduce the space required for construction, reduce the exposed area of the stope side and improve the safety of operation, the present application provides a mining method for steeply inclined thin ore body under broken surrounding rock condition.

[0004] The present application provides a mining method for steeply inclined thin ore body under broken surrounding rock condition, which adopts the following technical scheme:

[0005] The mining method for steeply inclined thin ore body under broken surrounding rock condition comprises the following steps:

[0006] S1, engineering geological condition investigation is conducted on the ore body and its surrounding rock to determine the stope structure parameters;

[0007] S2, the ore body is divided into ore rooms and ore pillars along the strike according to the length of the stope, and the ore body is continuously mined in two steps;

[0008] S3, mining preparation cutting engineering is constructed in the stope;

[0009] S4, a ramp is arranged at a certain distance from the ore body at the middle position of the ore body, a connecting roadway is constructed from the ramp to the other side of the ore body, and then the mining drifts are constructed on both sides of the connecting roadway close to the side with better surrounding rock stability, and the mining and filling are conducted in steps;

[0010] S5, after the first layer is mined, the filling is conducted, and after the filling is completed and the designed strength is reached, the second layer is mined, and the cycle is repeated until the stope mining is completed.

[0011] Optionally, in step S1, the rock mass quality classification and stability evaluation are required for the ore body, and then the stope structure parameters are further determined according to the Mathews graphical method and numerical simulation software.

[0012] Optionally, the length of the one-step stope and the two-step stope is consistent in the step S2, the stope width is the thickness of the ore body, and the stope layer height is 3.0-4.0 m.

[0013] Optionally, the mining preparation cutting engineering in the step S3 comprises an ore chute, a waste rock chute, and a filling air return shaft.

[0014] Optionally, in the step S4, the ramp is a spiral ramp, and a layer platform is formed every interval of a layer height, and a connecting roadway is constructed from each layer platform of the ramp to the other side of the ore body; and each layer platform is connected to different layers.

[0015] Optionally, in the step S4, if the thickness of the ore body is less than two widths of the drift, the remaining ore body is mined by the form of expansion after one drift is constructed.

[0016] Optionally, in the step S4, if the thickness of the ore body is more than two widths of the drift, the remaining ore body is mined by the vertical drift after one drift is constructed, and a permanent point column is left to support the stope.

[0017] In summary, the present application has the following beneficial technical effects:

[0018] 1. The present application reduces the distance between the ramp and the stope by the setting of the spiral ramp and the layer platform, greatly reduces the engineering quantity of the connecting roadway, and reduces the slope of the connecting roadway by each layer platform being responsible for one layer, thereby facilitating the ore transportation and equipment operation.

[0019] 2. The ore body is first analyzed professionally, and then the stope length is divided, one drift is first mined, then one drift is mined vertically, and then the drift is made into a concrete permanent point column to control the exposed area of the stope roof and side wall, thereby avoiding the broken surrounding rock from appearing cross-roofing or even the cracking of the ore body roof, and ensuring the safety of personnel operation. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a typical plan view of the mining scheme for the thickness of the ore body being 1-2 widths of the drift;

[0021] Figure 2 is a schematic view of the AA section in Figure 1 ;

[0022] Figure 3 is a schematic view of the BB section in Figure 1 ;

[0023] Figure 4 is a typical plan view of the mining scheme for the thickness of the ore body being more than 2 widths of the drift;

[0024] Figure 5 Fig. 1 is a schematic view of a CC profile in the mine body; Figure 4

[0025] Figure 6 Fig. 2 is a schematic view of a DD profile in the mine body; Figure 4

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] 1, ramp; 2, ore chute; 3, waste chute; 4, connecting roadway; 5, filling retaining wall; 6, stoping drift; 7, first sublevel; 8, ore body; 9, filling air return shaft; 10, second sublevel; 11, drill jumbo; 12, blast hole; 13, pillar. DETAILED DESCRIPTION

[0028] The following will be described in detail in combination with the accompanying drawings. Figures 1-6 The application will be further described in detail.

[0029] Example 1

[0030] Reference Figures 1-3 The application discloses a method for mining steeply inclined thin ore body under the condition of broken surrounding rock, which comprises the following steps:

[0031] Step S1, rock mass quality classification and stability evaluation are performed on the ore body and its upper and lower wall rocks, and then the stope structure parameters are obtained according to the Mathews graphical method and numerical simulation software; here, the upper wall rock (quartz porphyry) of the ore body is III-IV rock mass, the lower wall rock (Shidengzi limestone) is II-III rock mass, the upper wall exposed area is 100 m 3 For example, in order to control the stability of the upper wall, the stope structure parameters are set to 3.0x30.0 m.

[0032] Step S2, here, the ore body is divided into two stopes along the strike, and the ore body is continuously mined in two steps, one step stope and two step stope have the same length of 30.0 m, the stope width is the thickness of the ore body, and the stope sublevel height is 3.0 m.

[0033] Step S3, the preparation cutting engineering is constructed in the stope, including the ore chute 2, the waste chute 3 and the filling air return shaft.

[0034] ​​Step S4, first, the spiral ramp 1 is arranged at 6.0m from the ore body on the side with better stability of the surrounding rock in the middle of the ore body, the ramp 1 makes a layered platform (3m, 6m, 9m ore body, etc.) every 3.0m, the contact lane 4 is constructed from the layered platforms of the ramp 1 to the other side of the ore body, and then the 2.6x3.0m recovery access is constructed on both sides near the side with better stability of the surrounding rock; in the embodiment of the application, the thickness of the ore body is less than the width of two accesses, so after the construction of one access, the remaining ore body is recovered by expanding the brush.

[0035] Step S5, the recovery is carried out in the form of mining and filling, that is, after the recovery of the first layer, the filling is carried out, the filling retaining wall 5 is arranged in the contact lane 4 during the filling process, after the filling is completed and reaches the design strength, the recovery of the second layer is carried out, and the cycle is continued until the end of the recovery of the mining field.

[0036] Embodiment 2;

[0037] Reference Figures 4-6 The embodiment is different from the embodiment 1 in that the thickness of the ore body is greater than the width of two accesses, in step S4, after the construction of one access, the recovery is carried out vertically, first, one vertical access is recovered every 10m, second, the recovered vertical access is filled with high-strength concrete to make a permanent point column, then the other vertical accesses are recovered, and finally, after the layered recovery is completed, the filling is carried out according to the design requirements.

[0038] The above are preferred embodiments of the application, and are not intended to limit the protection scope of the application, so: any equivalent changes made according to the structure, shape, principle of the application should be covered within the protection scope of the application.

Claims

1. A method for mining steeply dipping thin ore bodies suitable for fractured surrounding rock conditions, characterized in that... Includes the following steps: S1. Conduct an engineering geological survey of the ore body and its surrounding rock to determine the structural parameters of the mining area; S2. Based on the length of the stope, the ore body is divided into stops and pillars along the strike, and the ore is continuously mined in two steps. S3. Carry out the pre-cutting and cutting work in the mining area; S4. At a certain distance from the ore body, a ramp is set up in the middle of the ore body. A connecting roadway is constructed from the ramp to the other side of the ore body. Then, the mining access roadway is constructed from the side of the connecting roadway with better surrounding rock stability to both sides, and mining and backfilling are carried out in stages. S5. After the first layer is mined, backfilling is carried out. After the backfilling is completed and the design strength is reached, the second layer is mined. This cycle continues until the mining of the stope is completed. During the mining process in step S4, if the ore body thickness reaches more than two mining access widths, mining will be carried out vertically after one mining access is constructed, and permanent support pillars will be left to support the stope; if the ore body thickness is less than two mining access widths, mining will be carried out in the form of widening after one mining access is constructed.

2. The method for mining steeply dipping thin ore bodies under fractured surrounding rock conditions according to claim 1, characterized in that: In step S1, the rock mass quality classification and stability evaluation of the ore body need to be carried out. Then, the stope structure parameters are further determined according to the Mathews graphical method and numerical simulation software.

3. The method for mining steeply dipping thin ore bodies under fractured surrounding rock conditions according to claim 1, characterized in that: In step S2, the length of the first-step stope and the second-step stope are the same, the width of the stope is equal to the thickness of the ore body, and the height of the stope stratification is 3.0 to 4.0 m.

4. The method for mining steeply dipping thin ore bodies suitable for fractured surrounding rock conditions according to claim 1, characterized in that: The mining preparation and cutting process in step S3 includes: ore pass, waste rock pass and backfilling return air shaft.

5. The method for mining steeply dipping thin ore bodies under fractured surrounding rock conditions according to claim 1, characterized in that: In step S4, the ramp is a spiral ramp, and a layered platform is built at every layer height. From each layered platform of the ramp, a construction connecting roadway is built to the other side of the ore body, so that each layered platform is connected to different layers.

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