Study on ultra-deep hole expansion blasting of collapse column in No.15226 fully mechanized caving face of Xinjing Mine
Collapse column was a geological structure often encountered in coal mining,which had a negative impact on the safety mining efficiency.The X3,X4,X5 and X6 collapse columns were exposed in No.15226 Face of Xinjing Mine.In order to ensure the safe mining of the working face and improve the mining efficiency,the collapse column was controlled by ultra-deep hole expansion blasting.Combined with geological data and geophysical data,the location and shape of four collapse columns were determined,and the arrangement and parameters of ultra-deep holes were determined.The construction technology of ultra-deep drilling hole was analyzed and the safety measures of ultra-deep hole blasting were discussed.The practice showed that the No.15226 Face successfully passed through the X5 and X6 collapse columns,and the consumption rate of the pick was reduced by 74.21%compared with the non-deep hole blasting control.And the advancing speed of the working face was increased by 16.1%.The study indicated that the ultra-deep hole blasting technology ensured the safe and efficient mining of the working face.