Safe and efficient mining method for thick ore body under fault condition

Abstract

The application discloses a safe and efficient mining method for thick and large ore body under fault conditions, which comprises the following steps: drilling downward parallel large-diameter deep holes in a rock drilling chamber, and blasting and mining in layers according to the inclination of a fault cutting surface; reserving a fault lower-plate bottom-protecting ore layer and a fault upper-plate top-protecting ore layer respectively in the lower plate and the upper plate of the fault; when the fault lower-plate bottom-protecting ore layer is mined, the downward parallel large-diameter deep holes in the fault and the fault upper-plate top-protecting ore layer can be less charged with explosives or not charged with explosives, and the fault is mined by natural caving or induced caving. Thus, the exposure time and adverse effects of the fault soft structure surface can be effectively controlled, favorable technical conditions are created for safe and efficient mining of the thick and large ore body under the fault conditions, the disturbance of blasting vibration to the roof and the side wall of the stope is further reduced, and finally the safe and efficient mining of the thick and large ore body under the fault conditions is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mining, in particular to a safe and efficient mining method for thick and large ore body under the condition of fault. BACKGROUND

[0002] The mining of thick and large ore body under the condition of fault usually has the following problems: (1) the ore block is easily cut by fault, which can cause large-area roof fall and rib spalling in the stope, and cause rock burst disaster; (2) the mining and cutting engineering and the drilling and blasting engineering in the fault influence range are difficult to construct, the roadway excavation and support are difficult and costly, and the blast hole is easily deformed and blocked by fault damage, and charging is difficult; (3) the stability of the ore and rock is poor, the stope boundary is not easy to control, which can cause large amount of mixed filling body and surrounding rock, high ore dilution rate and high mining loss rate.

[0003] The method of reducing the stope structure parameters can alleviate the stope falling speed, but the stope production capacity is significantly reduced, and the mining cost is greatly increased. Therefore, how to implement safe and efficient mining of thick and large ore body under the condition of fault is a problem to be solved at present. SUMMARY

[0004] In order to solve the problems of poor safety, high mining loss rate and low efficiency in the mining of thick and large ore body under the condition of fault in the prior art, the present application provides a safe and efficient mining method for thick and large ore body under the condition of fault, which comprises the following steps:

[0005] (1) constructing an ore outlet roadway and a cutting and bottoming roadway in the stope along the stage transportation flat roadway respectively, and then constructing a ore loading access, which connects the ore outlet roadway and the cutting and bottoming roadway;

[0006] (2) constructing a cutting shaft and an upward fan-shaped medium-length hole in the cutting and bottoming roadway, and forming a stope ore falling space after charging and blasting and ore removal;

[0007] (3) reserving a fault upper wall protecting ore layer and a fault lower wall protecting ore layer on the upper wall and the lower wall of the fault respectively;

[0008] (4) constructing a drilling chamber above the fault upper wall protecting ore layer, and constructing a plurality of downward parallel blast holes in the drilling chamber, the downward parallel blast holes pass through the fault upper wall protecting ore layer, the fault and the fault lower wall protecting ore layer, and are used for layered charging and blasting and layered ore removal of the downward parallel blast holes according to the inclination angle of the fault cutting surface

[0009] (5) the fault upper wall protecting ore layer and the fault and the fault lower wall protecting ore layer below the fault upper wall protecting ore layer realize fault ore falling in a natural caving or induced caving manner, no charge is used in natural caving, and the charge amount in induced caving is less than the conventional blasting charge amount.

[0010] (6) the ore body above the hanging wall of the fault is mined according to the order from bottom to top, and after the whole stope is mined, the goaf is filled.

[0011] Further, the step (4) further comprises shotcreting and bolting the rock chamber. The thickness of the floor protection layer on the lower side of the fault is 1.5-2.5 m, and the thickness of the roof protection layer on the upper side of the fault is 1.0-2.0 m. The diameter of the downward parallel blast hole is 110-120 mm, the row distance is 3.0-3.5 m, and the hole distance is 3.0-3.5 m. The charge amount in the step (5) is 10-20% of the conventional blasting charge amount.

[0012] In order to prevent the rock burst disaster caused by a large amount of ore falling from the fault, the layered mining needs to leave 4-5 m high caving ore in the stope each time, and all the goaf is emptied after the last ore falling.

[0013] As an example, the length of the stope is 30-50 m, the width is 10-12 m, and the stage height is 50-60 m. The length of the ore falling space of the stope is 30-50 m, the width is 10-12 m, and the height is 10-12 m, so as to ensure sufficient space for the downward parallel blast hole layering charge blasting compensation. The rock chamber is perpendicular to the stage transportation roadway, the ore drawing roadway and the cutting and bottoming roadway are parallel, and the angle between the ore drawing roadway and the ore loading approach is 45-50°. The ore body in the stope is divided into two steps of ore room and ore pillar recovery, and no inter-column is left between the ore room recovery and the ore pillar recovery.

[0014] Compared with the prior art, the present application has the following beneficial effects:

[0015] (1) The method can construct downward parallel large-diameter deep holes in the rock chamber, can layer charge blasting and layer mining according to the inclination angle of the fault cutting surface, and can effectively reduce the risk of stope rock burst disaster caused by fault caving compared with the traditional lateral caving or horizontal layer caving.

[0016] (2) The method reserves the floor protection layer on the lower side of the fault and the roof protection layer on the upper side of the fault, respectively, improves the integrity and stability of the fault during the stope recovery process, and creates favorable technical conditions for safe and efficient mining of thick and large ore bodies under the condition of the fault.

[0017] (3) The method of the present application recovers to the floor-ward protective ore layer under the fault, and the downward parallel large-diameter deep holes in the fault and the roof-ward protective ore layer on the upper and lower sides of the fault can be less charged with explosives or not charged with explosives, and the fault ore falling is realized by natural caving or induced caving, effectively solving the problem of charging difficulty caused by deformation of the blasting hole in the traditional lateral caving or horizontal slicing caving, saving the consumption of explosives, reducing the disturbance of blasting vibration on the roof and side slope of the stope, and greatly improving the production capacity of the stope and the safety of the recovery operation.

[0018] Therefore, the present application can safely and efficiently recover the thick and large ore body under the fault condition, and has strong operational flexibility, less consumption of explosives, and low loss and dilution. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Front view of the safe and efficient mining method for thick and large ore body under fault condition.

[0020] Figure 2 Front view of the safe and efficient mining method for thick and large ore body under fault condition.

[0021] Legend: ore loading access 1, stage transportation roadway 2, ore drawing roadway 3, large-diameter blast hole 4, floor-ward protective ore layer under the fault 5, fault 6, roof-ward protective ore layer on the upper side of the fault 7, rock drilling chamber 8, cutting and bottoming roadway 9. DETAILED DESCRIPTION

[0022] The present application will be described in detail below in combination with the drawings and specific examples.

[0023] This is an example of mining a thick and large ore body under fault condition, with an ore body thickness of 45m, a fault thickness of 15m, and a fault inclination of 40°, as shown in Figure 1 and Figure 2 The specific implementation steps are as follows:

[0024] (1) The stope structure parameters are set as: stope length 45m, width 12m, and stage height 50m. The ore body is divided into two steps of ore room and ore pillar recovery, and no inter-column is left between the one-step stope and the two-step stope, i.e. no inter-column is left between the ore room stope and the ore pillar stope.

[0025] (2) The ore drawing roadway 3 and the cutting and bottoming roadway 9 are constructed in the stope along the stage transportation roadway 2, respectively, and then a plurality of ore loading accesses 1 are constructed to connect the ore drawing roadway 3 and the cutting and bottoming roadway 9, and the included angle between the ore drawing roadway 3 and the ore loading access 1 is 45°, which is better within the range of 40°-45°.

[0026] (3) In the cutting bottom roadway 9, cut the cutting shaft and the upward fan-shaped medium-length hole, the upward fan-shaped medium-length hole is 70mm in diameter, the row distance is 1.8m, the hole bottom distance is 2.0m, the charging blasting and the ore drawing form the stope falling ore space. In order to ensure enough downward parallel deep hole layering blasting compensation space, the stope falling ore space is 45m in length, 12m in width and 12m in height.

[0027] (4) In the lower wall of the fault 6 and the upper wall, the fault lower wall protective bottom ore layer 5 with a thickness of 2.0m and the fault upper wall protective top ore layer 7 with a thickness of 1.8m are reserved respectively.

[0028] (5) Above the fault upper wall protective top ore layer 7, the rock drilling chamber 8 is constructed, and the rock drilling chamber 8 is supported by the shotcrete anchor net. Then, the downward parallel large-diameter blast hole 4 is constructed in the rock drilling chamber 8, the downward parallel blast hole is 110mm in diameter, the row distance is 3.0m, and the hole distance is 3.0m. According to the 40° inclined surface layering charging blasting and layering ore drawing, the formed blasting surface and the fault cutting surface keep parallel in the direction of the inclination angle, so as to avoid early exposure of the fault in the recovery process.

[0029] (6) When the fault lower wall protective bottom ore layer 5 is recovered, the fault 6 and the downward parallel large-diameter blast hole 4 in the fault lower wall protective top ore layer 5 and the fault upper wall protective top ore layer 7 can be less charged or not charged, and the natural caving or induced caving method is adopted to realize the fault falling ore, which can effectively solve the charging difficulty problem caused by the deformation of the traditional lateral caving or horizontal layering caving blast hole, save the explosive consumption, and reduce the disturbance of the blasting vibration to the stope roof and the side slope. In this embodiment, the induced caving method is adopted, and the charging amount in this example is 15% of the conventional blasting charging amount. According to the specific situation, the charging amount can be 10%-15% of the conventional blasting charging amount. After the layering ore drawing by charging blasting, the fault recovery is completed.

[0030] (7) The ore body above the fault upper wall protective top ore layer 7 is layering blasted and drawn according to the order from bottom to top. Each time of layering ore drawing needs to leave 4m-5m high caving ore in the stope, and after the last time of falling ore, the whole empty space is drawn out to prevent the rock burst disaster caused by a large amount of falling ore in the fault fracture zone. After the whole stope recovery is completed, the full tailings paste is used to fill the goaf, and the filling body strength is 1.0MPa-2.0MPa.

[0031] In some embodiments of the present application, according to specific actual conditions, when the fault is thin, the thickness of the floor and roof protection layers can be selected to be thin, the diameter of the downward parallel blast hole can be small, and the row distance and hole distance can be small. Generally, the thickness of the floor protection layer under the downwall of the fault is 1.5m-2.5m, and the thickness of the roof protection layer under the upwall of the fault is 1.0m-2.0m; the diameter of the downward parallel blast hole is 110mm-120mm, the row distance is 3.0m-3.5m, and the hole distance is 3.0m-3.5m. The stope structure parameters of the present application can be set as length 30m-50m, width 10m-12m, and stage height 50m-60m. Within this range, the present application method can be effectively used. The length of the stope ore falling space is 30m-50m of the stope length, the width is 10m-12m of the stope width, and the height is 10m-12m, within this range, enough downward parallel blast hole layer charging blasting compensation space can be ensured.

Claims

1. A safe and efficient mining method for thick ore body under fault condition, comprising the following steps: (1) constructing an ore drawing tunnel and a cutting floor tunnel respectively along the stage transportation roadway in the stope, and then constructing a loading access which connects the ore drawing tunnel and the cutting floor tunnel; (2) constructing a cutting shaft and an upward fan-shaped medium-length hole in the cutting floor tunnel, and forming a stope ore drawing space after charging and blasting and ore drawing; (3) reserving a fault upper wall protecting ore layer on the upper wall of the fault and a fault lower wall protecting ore layer on the lower wall of the fault; (4) constructing a rock drilling chamber above the fault upper wall protecting ore layer, and constructing a plurality of downward parallel blast holes in the rock drilling chamber, wherein the downward parallel blast holes pass through the fault upper wall protecting ore layer, the fault, and the fault lower wall protecting ore layer, and are used for downward parallel blast hole layering charging and blasting and layering ore drawing according to the fault cutting surface inclination angle, so as to control the exposure time and adverse effects of the fault weak structural plane; (5) the fault upper wall protecting ore layer and the fault and the fault lower wall protecting ore layer below the fault upper wall protecting ore layer are realized by natural caving or induced caving, wherein no charge is used in natural caving, and the charge amount in induced caving is less than the conventional blasting charge amount; (6) the ore body above the fault upper wall protecting ore layer is layering blasted, drawn, and filled in sequence from bottom to top, and after the whole stope is mined, the goaf is filled.

2. The safe and efficient mining method of thick ore body under fault condition according to claim 1, characterized in that: The step (4) further comprises shotcrete and anchor net supporting the rock drilling chamber (8).

3. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized in that: The thickness of the fault lower wall protecting ore layer is 1.5m-2.5m, and the thickness of the fault upper wall protecting ore layer is 1.0m-2.0m.

4. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized in that: The diameter of the downward parallel blast hole is 110mm-120mm, the row distance is 3.0m-3.5m, and the hole distance is 3.0m-3.5m.

5. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized in that: The charge amount in induced caving in the step (5) is 10%-20% of the conventional blasting charge amount.

6. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized in that: The layering ore drawing needs to leave 4m-5m high caved ore in the stope each time, and the whole goaf is drawn after the last caving, so as to prevent the rock burst disaster caused by a large amount of fault caving.

7. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized in that: The length of the stope is 30m-50m, the width is 10m-12m, and the stage height is 50m-60m.

8. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized by: The rock drilling chamber is perpendicular to the stage transportation roadway, the ore drawing tunnel and the cutting floor tunnel are parallel, and the included angle between the ore drawing tunnel and the loading access is 45°-50°.

9. The safe and efficient mining of thick ore bodies under fault conditions according to claim 1, characterized by: The length of the stope ore drawing space in the step (2) is 30m-50m, the width is 10m-12m, and the height is 10m-12m, so as to ensure enough space for downward parallel blast hole layering charging and blasting.

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