24m high step slope expansion blasting method for open pit mine

Abstract

The invention discloses a 24m high step slope expansion blasting method for an open pit mine. On a basis of considering advantages and disadvantages of a rotary drill and a down-the-hole drill fully,a way of combination operation of the rotary drill, the pore diameter of which is 310 mm, and the down-the-hole drill, the pore diameter of which is 165 mm, is adopted for hole arrangement. The methodcomprises a specific measure of adding 3-4 165 mm inclined holes parallel to a step slope between two front row 310 mm vertical holes. The method reduces a front row resistance line of high step blasting effectively and guarantees the perforating efficiency of the drills to the maximum extent, so that blasting economy is rationalized.

Description

technical field [0001] The invention relates to the technical field of mine blasting, in particular to a 24m high step side expansion blasting method in an open-pit mine. Background technique [0002] The existing side expansion method of the open-pit mine is to expand outward layer by layer according to the original 12-meter step level. When facing the two-by-two or even multiple groups of steps that have been merged in the previous stage, the current side expansion method needs to face steep and straight steps. Unfavorable conditions such as slope, narrow site, and dangerous operation of large equipment. In order to overcome the above unfavorable factors and speed up the expansion of the upper steps, the original two merged 12-meter steps are regarded as a 24-meter-high step for one-time piercing and assembly. However, with the increase of the height of the steps, the resistance line of the front row chassis is constantly increasing, and the front row of blastholes often ...

AI Technical Summary

Problems solved by technology

However, with the increase of the height of the steps, the resistance line of the front row chassis is constantly increasing, and the front row of blastholes often cannot effectively overcome the front row of resistance lines. After blasting, large blocks, roots and even rock walls are easy to appear in the front row of the steps.

The emergence of large blocks, roots or rock walls not only increases the workload of the secondary blasting, but also reduces the efficiency of the electric shovel and slows down the speed of the steps. Therefore, in the blasting of the 24-meter-high steps, it is necessary to overcome the large resistance of the front row. line technology

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