Application of Hole-by-hole Blasting Technology in Taihe Iron Mine (II)

Three different schemes have been designed and applied in the mine. After practice verification, the slash detonation and V-shaped detonation are mainly used. The example is 25ms between holes and 42ms between rows. The design parameters of each scheme are shown in Figure 1~3.

Figure 1 Square cloth hole Figure 2 Triangle cloth hole oblique line detonation

The three kinds of detonation schemes can realize the detonation by the hole. However, in practice, it is found that the square cloth hole scheme 1 has the largest number, the column and column mineral rock extrusion is not sufficient; the triangle cloth hole and the oblique line detonation scheme II The effect is better than the scheme; the triangular cloth hole V-type initiation scheme is the three-optimal, the explosion pile is fully squeezed, the large block is few, loose and uniform, and it is easy to excavate and transport.

3. Charge structure in the hole

In order to reduce the upper bulk, two types of in-hole charge structures have been adopted (see Figure 4):
(1) Continuous columnar charge, separated by air spacers at the upper blockage;

(2) Packing in sections, with air spacers in between.
The blasting effect of the two charging structures is not much different, but the blasting equipment with segmented charging consumes a large amount.

Figure 3 Triangle hole V-type detonation Figure 4 Charge structure

Third, the conclusion of the Taihe owing mine since the use of hole differential blasting technology, the blasting effect is significantly improved. This is mainly reflected in the following aspects:
(1) The blasting block is uniform, the block rate is low, the upper block rate is reduced by 80%, the secondary blasting amount is small, and the base is small;
(2) Controlling the direction of the explosion, reducing the loss of ore and depletion;
(3) It can better control the shape of the explosive pile, improve the looseness and uniformity of the pile, facilitate excavation and transportation, and give full play to the efficiency of the shovel loading and transportation equipment;
(4) Reduced blasting vibration and noise, and less flying stones.
The accuracy of the detonator delay time is the necessary guarantee for the successful realization of the hole-by-hole detonation. The delay is not accurate, which is easy to cause the detonation time to be disordered, and the blasting effect should not be achieved, and the rock throwing direction will be disordered after the detonation. Taihe iron ore using high-precision non-electric detonators Orica produced, basically meet the actual needs of the mine.