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Investigating the Energy Balance of Two Mining Methods Set in a Deep Underground Metal Mine in the U.S

Public Domain


Details

  • Personal Author:
  • Description:
    Hecla Mining Company (Hecla) operates the Lucky Friday Mine since 1958, which is an underground silver, lead, and zinc mine near Mullan, Idaho, USA. In the mid-1980s until 2020, the company relied on the Lucky Friday Underhand Longwall (LFUL) method for seismic control to mine (first) the Lucky Friday and (then) the Gold Hunter ore bodies. However, engineering challenges related to high in-situ rock stresses, squeezing ground conditions and seismic occurrences continued to increase as the production levels deepened to depths greater than 2,000 m below ground surface. In 2020, Hecla developed a new mining method called UCB (Underhand Closed Bench) which proactively induces fault slip in proximity of the mining front, improving safety and productivity at the mine. UCB was fully implemented at the Gold Hunter in 2021. Although preventing faults to slip at their critical load was identified as the main seismic control measure, the contribution of fragmented ore presents another component capable of reducing the seismic energy release measured at the mine. As part of the seismic hazard research initiative, the National Institute for Occupational Safety and Health (NIOSH) collaborated with Hecla to develop a series of numerical models using a 3-dimensional distinct element method (3DEC) to quantitatively investigate and compare the differences in the energy balance characteristics between the LFUL and the UCB methods. As a result, the numerical models were sensitive enough to capture the differences between the mining methods and were in good agreement with the field observations, recognizing the influence of blasted ore in seismic control. [Description provided by NIOSH]
  • Subjects:
  • Keywords:
  • Series:
    Mining Publications
  • ISBN:
    9780979497599
  • Publisher:
    American Rock Mechanics Association (ARMA)
  • Document Type:
    Text
  • Genre:
    Proceedings
  • Place as Subject:
  • CIO:
    National Institute for Occupational Safety and Health (NIOSH)
  • Division:
    SMRD - Spokane Mining Research Division
  • Topic:
    Workplace Safety & Health
  • Location:
    North America
  • NIOSHTIC Number:
    nn:20070433
  • Citation:
    58th US Rock Mechanics/Geomechanics Symposium, June 23-26, 2024, Golden, Colorado. Alexandria, VA: American Rock Mechanics Association (ARMA), 2024 Jun; :ARMA-24-0020
  • Federal Fiscal Year:
    2024
  • Peer Reviewed:
    False
  • Source Full Name:
    58th US Rock Mechanics/Geomechanics Symposium, June 23-26, 2024, Golden, Colorado
  • Collection(s):
  • Main Document Checksum:
    urn:sha-512:e15c22908efe6ca54180fc6dec27989f8145a40b15f0ff18689a1b184357fef207382151f451a04ddb8c2f5d0bc49788729c612118a23809811c88c2fc68dfe1
  • Download URL:
  • File Type:
    Filetype[PDF - 2.94 MB ]
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