Stemming zone fragmentation analysis of optimized blasting with top-column air decks

摘要

Trial application of air decks on a production shot improved fragmentation (32% reduction in x_(50)). Empirical fragmentation models and digital image processing software were used to estimate fragment size distribution of the blasted muck pile. The x_(20), x_(50), and x_(80) passing fractions, and top size were 42, 265, 683, and 1,455 mm, respectively. Air-deck application reduced explosives load in blast-holes, lowering total charging cost by US$20/hole (15% decrease) and the powder factor to an average of 0.86 kg/m~3 (12% decrease). Blast results were 443,624 t of blasted material from the block (90% of total muck pile) was smaller than 900 mm.