CN115142850A - Safe and efficient mining method for thick and large orebodies under fault conditions - Google Patents

Abstract

The invention discloses a safe and efficient mining method for thick and large ore bodies under fault conditions. The ore layer is produced; the bottom protection layer of the fault footwall and the top wall protection layer of the fault are reserved in the footwall and the hanging wall of the fault respectively; The parallel large-diameter deep holes can be loaded with less or no explosives, and the ore falling through the fault can be realized by natural caving or induced caving. This can effectively control the exposure time and adverse effects of the weak structural plane of the fault, create favorable technical conditions for the safe and efficient mining of thick and large ore bodies under fault conditions, and further reduce the disturbance of blasting vibration to the roof and side walls of the stope. Realize safe and efficient mining of thick and large ore bodies under fault conditions.

Description

Safe and efficient mining method for thick and large orebodies under fault conditions

technical field

The invention relates to the technical field of mining, in particular to a safe and efficient mining method for thick and large ore bodies under fault conditions.

Background technique

The mining of thick and large ore bodies under fault conditions usually has the following problems: (1) The ore block is cut by the fault, which may easily lead to a large area of roof caving in the stope, resulting in rock burst disasters; (2) Mining and cutting within the affected range of the fault Engineering and rock drilling and blasting projects are difficult to construct, roadway excavation and support are difficult and costly, blast holes are easily deformed and blocked by faults, and charging is difficult; (3) The stability of the ore rock is poor, and the stope boundary is not easy to control, resulting in the filling body and The amount of surrounding rock mixed in is large, and the ore dilution rate and mining loss rate are high.

The method of reducing the stope structure parameters can reduce the stope caving 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 bodies under fault conditions is an urgent problem to be solved.

SUMMARY OF THE INVENTION

In order to solve the problems of poor safety and high mining loss rate and low efficiency in the mining of thick and large ore bodies under fault conditions in the prior art, the present invention provides a safe and efficient mining method for thick and large ore bodies under fault conditions, the method comprising: Follow the steps below:

(1) Construct the mining roadway and the cutting and bottom-drawing roadway respectively along the staged transport roadway in the stope, and then construct the ore loading roadway, which connects the ore-exiting roadway and the cutting and drawing-bottom roadway;

(2) Construction of cutting patio and upward fan-shaped medium-deep holes in the cutting and bottoming tunnel, forming stope drop space after charge blasting and mining;

(3) Reserve the top protection layer of fault hanging wall and the bottom protection layer of fault foot wall in the hanging wall and foot wall of the fault respectively;

(4) A rock drilling chamber is constructed above the roof protection layer of the fault upper wall, and many downward parallel blastholes are constructed in the rock drilling chamber, and the downward parallel blastholes pass through the fault upper wall roof protection layer, fault, and fault. The bottom wall protects the ore layer, which is used for downward parallel blasting holes. It can blast the ore in layers according to the inclination of the fault cutting plane.

(5) For the top protection layer on the upper wall of the fault and the faults below it and the bottom protection layer on the footwall of the fault, the method of natural caving or induced caving is used to realize the ore falling through the fault. No charge is applied during natural caving, and the amount of charge used in induced caving is less than that of conventional caving. blasting charge.

(6) For the ore bodies above the top protection layer on the upper wall of the fault, blasting and mining are carried out in layers in the order from bottom to top. After the whole stope is mined, the goaf is filled.

Further, the step (4) also includes supporting the rock-drilling chamber 8 with spray bolts and meshes. The thickness of the bottom-protecting ore layer on the footwall of the fault is 1.5m-2.5m, and the thickness of the top-protecting layer on the upper wall of the fault is 1.0m-2.0m. The diameter of the downward parallel blast holes is 110mm-120mm, the row spacing is 3.0m-3.5m, and the hole spacing is 3.0m-3.5m. In the step (5), when the caving is induced, the charge is 10% to 20% of the conventional blasting charge.

In order to prevent the rockburst disaster that may be caused by a large number of ore falling from the fault, the caving ore with a height of 4m to 5m should be kept in the stope each time, and all the caving ore should be emptied after the last ore falling.

As an example, the stope length is 30m-50m, the width is 10m-12m, and the stage height is 50m-60m. The length of the stope drop space is 30m-50m in stope length, 10m-12m in width and 10m-12m in height, so as to ensure sufficient downward parallel blasting compensation space for layered charge blasting. The rock drilling chamber is perpendicular to the staged transport roadway, the mining roadway is parallel to the cutting and bottoming roadway, and the included angle between the mining roadway and the loading approach is 45° to 50°. The ore body in the stope is divided into two-step mining of the mining house and the ore pillar, wherein no pillar is left between the mining of the mining house and the mining of the ore pillar. (Please verify that this description is correct).

Compared with the prior art, the present invention has the following beneficial effects:

(1) The method of the present invention runs parallel large-diameter deep holes under the construction of the rock drilling chamber, and can blast the ore by layered charge according to the inclination angle of the fault cutting plane and discharge the ore in layers, compared with the traditional lateral collapse or horizontal layering. Collapse of the mine effectively reduces the risk of stope rock burst disasters that may be caused by fault fall.

(2) The method of the present invention reserves the bottom protection layer of the fault footwall and the top wall protection layer of the fault in the footwall and the hanging wall of the fault respectively, so as to improve the integrity and stability of the fault layer in the stope mining process. The safe and efficient mining of thick and large ore bodies has created favorable technical conditions.

(3) When the method of the present invention is recovered to the bottom protection layer of the fault footwall, the downward parallel large-diameter deep holes in the fault and the upper and lower wall roof protection layers of the fault can be loaded with less or no explosives, and the method of natural caving or induced caving can be adopted. It realizes ore falling through faults, effectively solves the problem of difficult charging caused by the deformation of blastholes caused by traditional lateral collapse or horizontal layer collapse, saves the consumption of explosives, and reduces the disturbance of blasting vibration to the roof and side walls of the stope. The production capacity of the stope and the safety of the mining operation have been greatly improved.

Therefore, the invention can safely and efficiently recover thick and large ore bodies under fault conditions, and has strong operational flexibility, less explosive consumption, and low loss and dilution.

Description of drawings

Figure 1 is a front view of a safe and efficient mining method for thick and large ore bodies under fault conditions.

Figure 2 is a top view of a safe and efficient mining method for thick and large ore bodies under fault conditions.

Reference signs: ore loading approach 1, staged transport level road 2, mining roadway 3, large-diameter blast hole 4, fault footwall bottom protection layer 5, fault 6, fault upper wall roof protection layer 7, rock drilling chamber 8. Cut the bottom roadway 9.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

This is an example of mining a thick and large ore body under the condition of a fault with an ore body thickness of 45m, a fault thickness of 15m, and a fault dip angle of 40°. Referring to Figure 1 and Figure 2, the specific implementation steps are as follows:

(1) The stope structure parameters are set as: stope length 45m, width 12m, stage height 50m. The ore body is divided into two steps of mining house and ore pillar, and no pillar is left between the one-step stope and the second-step stope, that is, no pillar is left between the mining house stope and the ore pillar stope.

(2) In the stope, the mining roadway 3 and the cutting and bottoming roadway 9 are respectively constructed along the staged transport roadway 2, and then a number of loading access roads 1 are constructed to connect the mining mining roadway 3 and the cutting and bottoming roadway 9, and the mining roadway 3. The angle between 3 and the loading route 1 is 45°, and it is better to choose within the range of 40°-45°.

(3) Construction of cutting patio and upward fan-shaped medium-deep holes in the cutting and pulling-bottom roadway 9. The diameter of the upward fan-shaped medium-deep holes is 70mm, the row spacing is 1.8m, and the hole bottom distance is 2.0m. Then the stope drop space is formed. In order to ensure sufficient compensation space for downward parallel deep hole layered blasting, the length of the stope drop space is 45m, the width is 12m, and the height is 12m.

(4) Reserve a 2.0m-thick bottom-wall protection ore layer 5 and a 1.8m-thick upper-wall roof protection layer 7 in the footwall and the upper wall of the fault 6, respectively.

(5) A rock drilling chamber 8 is constructed above the top protection ore layer 7 on the upper wall of the fault, and the rock drilling chamber 8 is supported by spray bolt nets. Then, the downward parallel large-diameter blast holes 4 are constructed in the rock drilling chamber 8. The diameter of the downward parallel blast holes is 110 mm, the row spacing is 3.0 m, and the hole spacing is 3.0 m. According to the 40° inclined plane, the ore is blasted and the ore is discharged in layers, that is, the formed blasting plane is kept parallel to the inclination direction of the fault cutting plane, so as to avoid prematurely revealing the fault during the mining process.

(6) When mining to the bottom protection layer 5 of the fault footwall, the downward parallel large-diameter blastholes 4 in the fault 6 and the fault footwall roof protection layer 5 and the fault upper wall roof protection layer 7 can be loaded with less or no explosives. , the use of natural caving or induced caving to realize fault caving can effectively solve the problem of difficult charging caused by the deformation of traditional lateral caving or horizontal layered caving, save the consumption of explosives, and reduce the impact of blasting vibration on the stope. Perturbation of the top plate and side gang. In this example, the method of induced caving is adopted, which is 15% of the conventional blasting charge. According to the specific situation, the charge amount can be 10%-15% of the conventional blasting charge amount. After the charge is blasted out of the ore, the fault recovery is completed.

(7) For the ore bodies above the top protection ore layer 7 on the upper wall of the fault, the ore bodies shall be blasted and discharged in layers in the order from bottom to top. The caving ore with a height of 4m to 5m should be kept in the stope for each layered ore, and all the ore will be emptied after the last ore drop, so as to prevent the rock burst disaster that may be caused by a large number of ore falling in the fault broken zone. After the whole stope is recovered, the goaf is filled with full tailings paste, and the strength of the backfill is 1.0MPa to 2.0MPa.

In still other embodiments of the present invention, according to the actual situation, when the fault is thin, the thickness of the bottom protection layer and the top protection layer can be selected to be thinner, the diameter of the downward parallel blast holes can be smaller, and the row spacing and hole spacing can be smaller. . Generally, the thickness of the bottom protection layer of the fault footwall is 1.5m~2.5m, and the thickness of the top protection layer of the fault hanging wall is 1.0m~2.0m; the diameter of the downward parallel blasting hole is 110mm~120mm, and the row spacing is 3.0m~3.5m; The distance is 3.0m ~ 3.5m. The stope structure parameters of the present invention can be set to be 30m-50m in length, 10m-12m in width, and 50m-60m in stage height. Within this range, the method of the present invention can be effectively used. The length of the stope drop space is the stope length of 30m~50m, the width is the stope width of 10m~12m, and the height is 10m~12m. Within this range, enough downward parallel blasting hole layered charge blasting compensation space can be guaranteed .

Claims (9)

1. A safe and efficient mining method for thick and large ore bodies under fault conditions, comprising the steps of: (1) Construct the mining roadway and the cutting and bottom-drawing roadway respectively along the staged transport roadway in the stope, and then construct the ore loading roadway, which connects the ore-exiting roadway and the cutting and drawing-bottom roadway; (2) Construction of cutting patio and upward fan-shaped medium-deep holes in the cutting and bottoming tunnel, forming stope drop space after charge blasting and mining; (3) Reserve the top protection layer of fault hanging wall and the bottom protection layer of fault foot wall in the hanging wall and foot wall of the fault respectively; (4) A rock drilling chamber is constructed above the roof protection layer of the fault upper wall, and many downward parallel blastholes are constructed in the rock drilling chamber, and the downward parallel blastholes pass through the fault upper wall roof protection layer, fault, and fault. The bottom wall of the footwall is used to protect the bottom of the ore layer, which is used for downward parallel blasting. It can blast the ore and mine the ore in layers according to the inclination of the fault cutting plane, and control the exposure time and adverse effects of the weak structural plane of the fault; (5) For the top protection layer on the upper wall of the fault and the faults below it and the bottom protection layer on the footwall of the fault, the method of natural caving or induced caving is used to realize the ore falling through the fault. No charge is applied during natural caving, and the amount of charge used in induced caving is less than that of conventional caving. blasting charge. (6) For the ore bodies above the top protection layer on the upper wall of the fault, blasting and mining are carried out in layers in the order from bottom to top. After the whole stope is mined, the goaf is filled. 2 . The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1 , wherein the step (4) further comprises spraying bolt net support for the rock drilling chamber 8 . 3 . 3. The safe and efficient mining method for thick and large orebodies under fault conditions according to claim 1, characterized in that: the thickness of the bottom protection layer of the fault footwall is 1.5m～2.5m, and the thickness of the top wall protection layer of the fault is 1.5m to 2.5m. 1.0m to 2.0m. 4. The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1, characterized in that: the diameter of the downward parallel blastholes is 110mm to 120mm, and the row spacing is 3.0m to 3.5m; 3.0m to 3.5m. 5 . The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1 , characterized in that: in the step (5) inducing caving, the charge is 10% to 20% of the conventional blasting charge. 6 . 6. The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1, characterized in that: said layered ore mining needs to keep 4m-5m high caving ore in the stope each time, After the last ore fall, it will be completely empty to prevent the rock burst disaster that may be caused by a large number of ore falling from the fault. 7 . The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1 , wherein the length of the stope is 30m-50m, the width is 10m-12m, and the stage height is 50m-60m. 8 . 8. The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1, characterized in that: the rock drilling chamber is perpendicular to the staged transport roadway, the mining roadway and the cutting and bottom-drawing roadway are In parallel, the included angle between the mining tunnel and the loading approach is 45° to 50°. 9. The safe and efficient mining method for thick and large ore bodies under fault conditions according to claim 1, characterized in that: the length of the stope falling space described in step (2) is the stope length of 30m to 50m, and the width is The width of the stope is 10m-12m, and the height is 10m-12m, so as to ensure sufficient compensation space for layered charge blasting of downward parallel blastholes.

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