NIOSHTIC-2 Publications Search

Control of flyrock in blasting.

Authors
Fletcher-LR; D'andrea-DV
Source
Paper in Proceedings of the 12th Conf on Explosives & Blasting Tech Atlanta, Georgia, 2/9-14/86 :11 pages
Link
NIOSHTIC No.
10007511
Abstract
Excessive flyrock, which is blasted rock that travels beyond the secured blast area, is responsible for 25 pct of the blasting injuries that occur in surface mining. Excessive flyrock is also a frequent cause of damage to mine equipment and facilities. Flyrock is produced when explosive energy is excessive for the amount of burden, stemming is inadequate, or the energy is too rapidly vented through a zone of weakness in the rock. When this happens, much of the explosive energy is used to throw rock, rather than to create fragmented rock and controlled displacement of the burden material. Geology, improper blast design, or carelessness can cause unwanted flyrock. The operator must learn how to change blasting methods when shooting in geology that favors the production of flyrock. Other factors such as powder factor, pattern layout, delay sequence, stemming height, drilling accuracy, and hole-loading methods should also be evaluated if excessive flyrock is being generated.
Keywords
Rock-bursts; Blasting-agents; Mining-industry; Surface-mining; Injuries; Injury-prevention; Mining-equipment; Explosion-damage; Explosives; Explosion-venting; Geology
Publication Date
19860101
Document Type
OP; Conference/Symposia Proceedings
Fiscal Year
1986
Identifying No.
OP 36-90
NIOSH Division
TCRC
Source Name
Paper in Proceedings of the 12th Conf. on Explosives & Blasting Tech., Atlanta, Georgia, 2/9-14/86
State
GA; MN
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division