Experiment on High Efficient Drilling and Blasting Construction for Mine Inclined Shaft in Red Clay

According to the mine gateway driving operation in red clay,the drilling and blasting construction technique applied would often have the borehole drilling difficulty,the serious requirement of the borehole parameter design,the driving speed low and other problems.The paper had the analysis and study on the borehole drilling and blasting mechanism in the red clay individually.With the improvement of the borehole drilling tools,the EZ1-21/2 hand type pneumatic drill with auger bit and auger rod was applied to the borehole drilling operation and the borehole drilling quality and speed could be highly increased.With the optimization of the borehole pattern,angle,depth,explosive loading and other blasting parameters and the twice and two sectional millisecond delay blasting technology,the utilization rate of the blasting boreholes was improved from previous 70% to over 90%.The driving rate of the single circulation was improved from 1.30 m to 1.75 m.The missed blasting rate was reduced from 24% to about 3%.Thus the profile shape results would be good and the driving speed could be highly increased.