Blasting Hazards in Sulfide-Bearing Ore Bodies

Details

• Personal Author:
  Miron, Yael
• Description:
  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 [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Explosions Explosive Agents Mining Occupational Health Safety Sulfides
• Keywords:
  Ammonium Nitrate/Fuel Oil ANFO Coal Mining Explosive Hazards Explosives Metal Mining Mining Industry Stone Mines Surface Mining
• Series:
  Mining Publications
• ISSN:
  0889-0668
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  Arizona ; California ; Nevada ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  11
• Issue:
  1
• NIOSHTIC Number:
  nn:10004016
• Citation:
  J Explos Eng 1993 May/Jun; 11(1):38-40,42-46
• Federal Fiscal Year:
  1993
• Peer Reviewed:
  False
• Source Full Name:
  The Journal of Explosives Engineering
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:7de4a1413c0b97bf0286d25d5df21ed4bd9015df26b8f6b807f398c7265271f3685c4bdd6dd44a68030f8774fbf27b5f76e816c38fe3665ee3734938cce8148b
• Download URL:
  https://stacks.cdc.gov/view/cdc/219534/cdc_219534_DS1.pdf
• File Type:
  [PDF - 531.32 KB ]