关键词: 地下开采, 乳化炸药, 微囊, 上向孔, 爆轰性能

Abstract: In order to solve the sloughing problem and weak low temperature resistant performance of emulsion explosives during pumping into the upward blast holes of underground metal mine,a novel underground mining emulsion explosive with thickening microcapsules was developed to realized thickening in the hole.The viscosity and pumping process of emulsion explosive were not affected by the addition of thickening microcapsules,when reaching the point of the pipe nozzle,the thickening microcapsules would be damaged by the highspeed shearing action and then released the thickening agent to the emulsion explosive,increasing the viscosity of the emulsion explosive promptly.The thickening microcapsules were spherical and particle size about 2 mm,which could effectively encapsulate the thickening liquid.After the highspeed shearing,the thickening microcapsules released the thickening agent which would distribute in the emulsion matrix with a linear network structure,achieving the thickening effect of emulsion explosive in the borehole.The viscosity of underground mining emulsion explosive with 2% of thickening microcapsules after shearing was 127.9 Pa·s,which met the requirement of stable adhesion of emulsion explosive in the borehole.The experimental results showed that the detonation velocity of the emulsion explosive with 2% of thickening microcapsules after shearing was 5 030 m/s,and was still 4 618 m/s after storing at the temperature of -20 ℃ for 12 h,which indicated that the underground mining emulsion explosive had an excellent detonation performance and lowtemperature resistance performance.The underground mine emulsion explosive with thickened microcapsule can meet the requirement of explosive performance in underground metal mining.