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An analysis and prevention of flyrock accidents in surface blasting operations.

Bajpayee TS; Verakis HC; Lobb TE
Proceedings of the 30th Annual Conference on Explosives and Blasting Technique, New Orleans, Louisiana, February 1-4, 2004, 2004 Feb; 2:1-10
Blasting is a primary means of extracting minerals and ores at surface mining operations. The domestic consumption of explosives and blasting agents in 2001 was about 5.25 billion lb. Flyrock is always a major concern for the blaster. Flyrock from surface blasting operations has caused serious injury and death to employees and other persons. Injuries due to flyrock and the lack of blast area security accounted for more than two-thirds of all blasting-related injuries in surface coal, metal, and nonmetal mines during 1978-2002. Selected accidents due to flyrock and lack of blast area security in surface mining are presented in this paper. Incidents related to construction blasting are also described. Techniques to mitigate blasting accidents are discussed. These include proper blast design, driller-blaster communication, inspection before loading and firing the blast, removing employees from the blast area, controlling access to the blast area, and using a blasting shelter. An experienced driller could detect potential problem areas such as voids, mud seams, incompetent rocks, and other irregularities by observing the progress of drilling. The drill log should include the details of any unusual or exceptional circumstances noticed during drilling. A blaster may need to alter the loading configuration to alleviate potential problems. Basic blast design is sometimes taken for granted and assumed to be proper for the conditions encountered, but one size does not fit all. It is known from the physics of blasting that the explosive energy takes the path of least resistance. The path of least resistance could generate flyrock, depending on the blast site conditions. A combination of borehole tracking and laser profiling can assist in improving the design of a blast. The blaster can use these tools to adjust borehole loading to match site conditions.
Surface-mining; Explosives; Injuries; Safety-research; Coal-mining; Metal-mining; Nonmetal-mining; Geology; Construction
NIOSH Pittsburgh Research Laboratory, P.O. Box 18070, Pittsburgh, PA 15236
Publication Date
Document Type
Conference/Symposia Proceedings
Fiscal Year
NIOSH Division
Priority Area
Research Tools and Approaches: Control Technology and Personal Protective Equipment
Source Name
Proceedings of the 30th Annual Conference on Explosives and Blasting Technique
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division