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Blasting hazards in sulfide-bearing ore bodies.

Authors
Miron Y
Source
J Explos Eng 1993 May/Jun; 11(1):38-40,42-46
Link
NIOSHTIC No.
10004016
Abstract
Two unplanned detonations occurred recently during surface blasting operations in sulfide-bearing ores at a Nevada gold mine. Other premature detonations have also reportedly occurred at other Nevada, California and Arizona gold mines within the past few years, with increasing frequency. Similar unplanned detonations have happened in copper mines, in a coal mine, and in a limestone mine which had oil shale bands containing pyrite interspersed in the limestone. The common denominators in all these events were the presence of sulfide in the ores being mined and the use of ammonium nitrate-fuel oil (ANFO) explosive in the blasting. This report delineates the basic causes for these accidents. These are the exothermic oxidation of pyrite (FeS) and formation of ferrous sulfate (FeSO), the exothermic and energetic reaction of the resultant ferrous sulfate with ANFO-based explosives, and the associated elevated temperatures that can set off detonators and explosives in the boreholes. Recommendations for safe operation for all mines containing sulfide ores include monitoring of temperatures in the blast holes, analyzing for sulfate and ferrous ions, and limiting the time between loading and firing in accordance with conditions in the blast holes
Keywords
Mining industry; Surface mining; Metal mining; Coal mining; Stone mines; ANFO; Ammonium nitrate/fuel oil; Explosives; Explosions; Explosive hazards; Sulfides
CODEN
JEXEDL
Publication Date
19930501
Document Type
Journal Article
Fiscal Year
1993
NTIS Accession No.
NTIS Price
Identifying No.
OP 210-93
Issue of Publication
1
ISSN
0889-0668
Source Name
The Journal of Explosives Engineering
State
NV; CA; AZ
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