Technical Measures on Lowering Boulder Yield during Deep-hole Blast in Underground Mine

To lower blasted boulder yield is one of the most important technical considerations in deep-hole blasting operations of mine. The location, where blasted boulder occurs in drill hole blasting of underground mine, and its causes are analyzed in this paper. The influence of specific charge, hole arrangement, charge structure, stem length, millisecond interval and ignition mode on the yield of the blasted boulder is analyzed Some measures to lower boulder yield in deep hole blasting of underground mine are presented through the optimization of blasting operation parameters as follows: lowering deep hole blasting effect of geology structure, rationally determining specific charge, using technique of wide-space small burden blasting, technique of manifold charge structure and technique of millisecond compression blasting, strengthening the management of boring construction and blasting construction. Those measures bring about good results in engineering applications.