Method for improving blasting effect of upward fan-shaped medium-length hole

Abstract

The invention discloses a method for improving the blasting effect of an upward fan-shaped medium-length hole. The method comprises the steps that step type blasting stoping is carried out in a cutting roadway and a rock drilling roadway from top to bottom, upper layered blasting is carried out to break ore, and ore removal is carried out in a roadway with a gradient at the bottom. According to the method, blasting top suspension is effectively eradicated, the amount of ore hanging on the wall of the goaf is reduced, the ore recovery rate is effectively increased, meanwhile, the boulder rate can be further reduced, and the method has an important promoting effect on safe, green, economical and environment-friendly mining of large underground mines in the open stoping subsequent filling method in the segmented drilling stage.

Description

Technical Field

[0001] The invention belongs to the field of medium-deep hole blasting recovery of ferrous metal mines, in particular to a recovery process for improving the blasting effect of the bottom of an upward fan-shaped medium-deep hole. Background Art

[0002] As the scale of iron ore mining continues to expand, shallow resources are gradually exhausted. Underground mining has the following technical difficulties: Problem 1: The pillarless sublevel caving mining method is widely used for its safety, efficiency and economy. The amount of iron ore mined accounts for more than 80% of the total amount of underground ore mined, but its dilution has always been a global problem. Problem 2: Most iron ore bodies have complex occurrences, poor adaptability of stope structures, and design and recovery losses of about 40%. How to reduce the loss rate has always been a problem that plagues underground iron ore mining. Problem 3: With the increase in mining depth, ground pressure becomes prominent and operating safety conditions are poor; there is a lack of research on the mechanism of surface collapse and cracking and the law of settlement, which seriously threatens safe production. The above technical difficulties have seriously restricted the production and development of mines. Regarding the recovery rate problem mentioned in Problem 2, the recovery rate of many iron mines cannot meet the minimum index standard of industry standards; the main reasons are analyzed as follows: mainly due to poor ore body occurrence conditions, surrounding rock properties, complex engineering and hydrogeology, poor adaptability of mining technology, blasting recovery technology, and stope structure.

[0003] For the current large-scale underground mines, the staged empty-site subsequent filling mining method is generally adopted, which is conducive to safe, efficient and large-scale production. Therefore, in the staged rock drilling stage empty-site subsequent filling mining method, the layer height is generally high in view of the relatively simple and stable engineering geology and surrounding rock properties, which puts higher requirements on the quality of blasting and mining. In the staged rock drilling stage empty-site subsequent filling mining method, the mining method is step-by-step blasting and mining from top to bottom; in extremely inclined ore bodies and inclined ore bodies, the upper layer can generally provide blasting compensation space for the lower layer, and the blasting quality is relatively controllable and the effect is also good. However, the upper layer is affected by the depth of the medium and deep holes and the small number of free surfaces. The blasting clamping effect at the bottom of the medium and deep holes is large, which seriously affects its blasting quality.

[0004] Based on the existing problems in the current mining reality, a set of solutions to the problem is proposed. Summary of the invention

[0005] The present invention provides a method for solving the problem of the top hanging caused by the large blasting clamping effect at the bottom of the upward fan-shaped medium-deep hole in the high-stage empty field subsequent filling mining process, thereby further improving the ore recovery rate.

[0006] In order to achieve the above-mentioned object of the invention, the present invention adopts the following technical scheme:

[0007] A method for improving the blasting effect of upward fan-shaped medium-deep holes, the method comprises the following steps: performing step-type blasting and mining from top to bottom in cutting tunnels and rock drilling tunnels, blasting the upper layered blasting rows to break off the ore, and centrally mining the ore in the tunnel with a slope at the bottom.

[0008] Further technology of the present invention:

[0009] Preferably, the cutting tunnel is arranged according to two pitches, the gun row spacing close to the cutting well side is 1.2m, and a reinforced row with a row spacing of 0.5m is arranged, the row spacing of other gun rows is 1.5m, and the reinforcement hole bottom spacing is arranged at 1.3m.

[0010] Preferably, the blast rows in the rock drilling tunnel are arranged in a fan shape, with a row spacing of 1.8 m and a hole bottom distance of 2.8-3.2 m. The hole bottom distance of medium and deep holes exceeding 25 m is controlled at 2.4-2.6 m.

[0011] Preferably, the blasting method adopts a millisecond delay hole-by-hole and row-by-row detonation method, continuous coupling charging in the hole and reverse detonation technology, wherein single-hole double detonating detonators and detonators are used for deep holes in cutting tunnels, and single-hole single detonating detonator and detonators are used for rock drilling tunnels.

[0012] Preferably, the delay time between holes is 20 ms, and the delay time between rows is 60-120 ms.

[0013] The beneficial effects of the present invention are:

[0014] The present invention is to improve the effect of upward fan-shaped medium-deep hole blasting. The technical method is mature, simple in process, easy to operate, and has the remarkable characteristics of safety, environmental protection, high efficiency, and economy. This method of improving the blasting effect will effectively prevent blasting hanging tops, reduce the amount of ore hanging on the wall in the goaf, effectively improve the ore recovery rate, and further reduce the large block rate at the same time, which has an important role in promoting the safe, green, economical, and environmentally friendly mining of large underground mines in the staged rock drilling stage and subsequent filling method. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0016] Figure 1 Schematic diagram of cutting tunnel and rock drilling tunnel.

[0017] Figure 2 Schematic diagram of blasthole arrangement. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be further described in detail below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention but not all. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0019] like Figure 1-2 Anhui Development Mining Co., Ltd. has two mining areas, namely Lilou Iron Mine and Wuji (North Section) Iron Mine. They are medium-to-large underground mines. They adopt the open-pit filling mining method in the stage of segmented rock drilling. The stage height is 100m and the layer height is 25m. The Pusch hardness coefficient f of the ore is 12-16. The rock drilling equipment used is the simba1354 trolley, with an upward fan-shaped hole arrangement and a medium-deep hole diameter of 80mm. The mining method is step-by-step blasting from top to bottom, with ore falling by blasting in the upper layer and concentrated ore discharge from the bottom structure.

[0020] In the construction process of the mining project, the slope of the tunnel floor is increased from 3‰ to 3%-5%. In this embodiment, 3% is selected, and the upper layer blasting height is controlled below 23m.

[0021] The controlled height of the cutting well exceeds the depth by 1m, and the vertical depth of the upward fan-shaped medium-deep hole in cutting lane 1 exceeds the depth by 1m.

[0022] When designing medium-long holes, the cutting lanes are set at two pitches. The row spacing of the blastholes close to the cutting well is 1.2m, and a reinforced row with a row spacing of 0.5m is set. The row spacing of other blasthole rows is 1.5m, and the bottom spacing of the reinforced holes is arranged at 1.3m.

[0023] The medium-deep holes in rock drilling tunnel 2 are arranged in a fan shape with a row spacing of 1.8m. The distance from the bottom of the hole is generally 2.8-3.2m. The distance from the bottom of the medium-deep holes exceeding 25m is appropriately reduced and controlled at 2.4-2.6m.

[0024] The blasting method adopts millisecond delay hole-by-hole and row-by-row detonation, continuous coupled charging in the hole and reverse detonation technology. Among them, single-hole double detonating detonators and detonators are used for deep holes in cutting tunnels, and single-hole single detonating detonator and detonators are used for rock drilling tunnels. The delay time between holes is 20ms, and the delay time between rows is 60-120ms.

[0025] The blastholes are plugged with bagged Marisan material, and the reserved length for hole plugging is reserved according to the requirements of hole mouth distance, and the hole mouth distance is reserved as 0.4-1.2m.

[0026] Each blasting is organized according to 2-4 rows. The blasting is carried out from top to bottom. The blasting steps are set according to 4-8 rows. Generally, the row spacing of the upper layer is set to a larger value, and the blasting steps of the lower layer are set to a smaller value.

[0027] The above contents are merely examples and explanations of the structure of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for improving the blasting effect of upward fan-shaped medium-deep holes, characterized in that: The method is to carry out step-by-step blasting and mining in the cutting and drilling tunnels from top to bottom, with the upper layer blasting to break up the ore and the bottom tunnel with a slope to concentrate the ore.

2. A method for improving the effect of upward fan-shaped medium-deep hole blasting according to claim 1, characterized in that: The cutting tunnel is set up with two pitches. The spacing between the gun rows close to the cutting well is 1.2m, and a reinforced row with a spacing of 0.5m is set. The spacing between other gun rows is 1.5m, and the bottom distance of the reinforced hole is arranged at 1.3m.

3. A method for improving the effect of upward fan-shaped medium-deep hole blasting according to claim 1, characterized in that: The blast rows in the rock drilling tunnel are arranged in a fan shape, with a row spacing of 1.8m and a hole bottom distance of 2.8-3.2m. The hole bottom distance for medium and deep holes exceeding 25m is controlled at 2.4-2.6m.

4. A method for improving the effect of upward fan-shaped medium-deep hole blasting according to claim 1, characterized in that: The blasting method adopts millisecond delay hole-by-hole and row-by-row detonation, continuous coupled charging in the hole and reverse detonation technology. Among them, single-hole double detonating detonators and detonators are used for deep holes in cutting tunnels, and single-hole single detonator and detonators are used for rock drilling tunnels.

5. A method for improving the effect of upward fan-shaped medium-deep hole blasting according to claim 4, characterized in that: The delay time between holes is 20ms, and the delay time between rows is 60-120ms.

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