What is underground mine chamber blasting?

Underground mine chamber blasting is only used under special circumstances, such as goaf treatment, ore body fractures are very developed, or the rock is extremely hard and rock drilling is very difficult. Yangjiazhangzi molybdenum drug once came extrusion chamber blasting method, in Gongchangling iron ore, iron ore Jingtieshan have used this blasting method. Take Yangjiazhangzi as an example, the parameters are as follows:

The minimum resistance line of the drug room is 7~8m; the horizontal distance of the drug room is 4~6m; the number of chamber layers is 7; the drug room is 92; the looseness coefficient after extrusion is 1.162; the explosive consumption is single; f=10~12, q= 0.6kg/t, f=8, q=0.4kg/t, total charge 113.4t; detonation with 9-segment millisecond detonator. As shown in Figure 1.

Figure 1 Schematic diagram of drug room drop

(É‘) with drug room; (b) drug-free room

1-section 1.5×1.8m ² drug room roadway; 2-section 1.2×1.8m ² ;

3-well 0.5m drug well; 4-filled with broken rock