Blast Designs to Improve Dragline Stripping Rates. Final Report: Phase I

摘要

This report is in accordance with Phase I of the United States Department of Energy and Bureau of Mines Contract No. USDOE DE-AC01-77QQ90147. A thorough literature search was conducted and the current mining practice at nine coal stripping operations reviewed in detail. A review of the state of the art of blast design using current theory and practice is presented. Based upon this information, a series of recommendations are presented and a detailed test program is outlined for three operations. The recommendations to increase dragline productivity by improved blast design are directed at filling the bucket more quickly, with greater consistency and with a better fill factor: (a) overburden fragmentation, (b) muckpile displacements, and (c) blasting reliability. Recommended blast design concepts and operating procedures to provide the desired blast performance include: (1) Increase energy input per BCY by 40 to 100 percent and improve the effective powder distribution by modifying blast parameters such as burden and spacing, collar heights, toe burden, delay intervals and blast tie-in; (2) Introduce use of blast hole dewatering, dryliners and bulk AN/FO for wet holes; (3) Improve quality control in establishing shot patterns and charging blast holes. (ERA citation 05:000029)