Prototype Borehole Miner Selectively Extracts Gold from Permafrost

Details

• Personal Author:
  Miller AL ; Savanick, George A.
• Description:
  Assess the technical feasbility of mining small and/or deeply buried frozenplacer deposits from the surface through boreholes. Placer deposits in permafrost often contain up to 15% cobbles and boulders. Because of erratic loading on the bit caused by elasticity and heterogeneity of the ice-and-gravel matrix, these deposits are extremely difficult to excavate. The approach taken in this research project was to mine only the ore-bearing portion of the deposit using a high-pressure water jet to thaw the gravels and a downhole hydraulic-lift-type pump to bring the ore to he surface as slurry. Full-scale jetting tests in frozen gravel were completed, and the data were used to design a jet excavator. The excavator will deliver a water flow of 890 L/min through a 15.7 mm diam nozzle at 6,900 kPa. The prototype slurry pump was designed to lift minus 15 cm gravels to the surface from a depth of 15 m. [Description provided by NIOSH]
• Subjects:
  Mining Occupational Health Safety
• Keywords:
  Boreholes Gold Gravel Jet-Pumps Mining-industry Slurry
• Series:
  Mining Publications
• ISSN:
  0271-3888
• Publisher:
  U.S. Department of Labor, Mine Safety and Health Administration
• Document Type:
  Text
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Division:
  PRL - Pittsburgh Research Laboratory
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  20-21
• NIOSHTIC Number:
  nn:10001099
• Citation:
  Holmes Saf Assn Bull 1998 Feb; :20-21
• Contact Point Address:
  National Institute for Occupational Safety and Health, Pittsburgh Research Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA 15236
• CAS Registry Number:
  Gold (CAS RN 7440-57-5)
• Federal Fiscal Year:
  1998
• Peer Reviewed:
  False
• Source Full Name:
  Holmes Safety Association Bulletin
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:90ec4f4a8a3102012d5b0489e3d364bb032956e0f11d6ab03679fe010f6055946849af21ce05cc24f81c19a42cac42634224709b74a8f19d493d6809d42f31f0
• Download URL:
  https://stacks.cdc.gov/view/cdc/219378/cdc_219378_DS1.pdf
• File Type:
  [PDF - 401.15 KB ]