mining cycle

• Outline of the Mining Cycle

  • WHAT IS MINING?
  • MINE LIFE CYCLE
  • LIFE CYCLE OF DEPOSITS
  • LIFE-CYCLE OF A MINE PROJECT
  • STAGES IN THE LIFE CYCLE OF A MINE PROJECT
  • ENVIRONMENTAL IMPACTS OF NONRENEWABLE MINERAL RESOURCES
• Mining


  The activity that removes from the earth’s crust the abnormal concentration of metal found in the deposit
• Mine


  An opening or excavation of the earth from which minerals are extracted
• Mine Life Cycle

  1. Exploration

  2. Mining

  3. Reclamation (or Closure)
• Stages in the Life Cycle of a Mine Project


  1. Prospecting (Mineral Deposit)

  2. Exploration (Ore Body)

  3. Development

  4. Exploitation (Mine)

  5. Reclamation
• Environmental Impacts of Nonrenewable Mineral Resources


  • Sources of Metal Pollution
  • Harmful Environmental Effects of Mining
  • Persistent, Bio-accumulative and Toxic (PBT): Lead, Mercury, Cadmium, Arsenic
• Prospecting and exploration, precursors to actual mining, are linked and sometimes combined
• Development and exploitation are closely related stages; they are usually considered to constitute mining proper and are the main province of the Mining engineer
• Reclamation has been added to these stages since the first edition, to reflect the times
• Closure and reclamation of the mine site has become a necessary part of the mine life cycle because of the demands of society for a cleaner environment and stricter laws regulating the abandonment of a mine
• The overall process of developing a mine with the future uses of the land in mind is termed sustainable development
• The fifth stage of the mine is of paramount importance and should be planned at the earliest possible time in the life of the mine
• The five stages in the life of a mine are summarized in Table 1
• Prospecting methods include direct (physical geologic) and indirect (geophysical, geochemical) methods
• Exploration involves defining the extent and value of ore through examination and evaluation
• 2002; p.8
• Mining Proper

  1. Acquire mining rights (purchase or lease), if not done in stage 2

  2. File environmental impact statement, technology, assessment, permit

  3. Construct access roads, transport system

  4. Locate surface plant, construct facilities

  5. Excavate deposit (strip or sink shaft)
• Exploitation (Mine)

  1. Factors in choice of method: geologic, geographic, economic, environmental, societal safety

  2. Types of mining methods: Surface (open pit, open cast, etc.), Underground (room and pillar, block caving, etc.)

  3. Monitor costs and economic payback (3 - 10 yr)
• Reclamation (Real estate)


  Restoration of site: Removal of plant and buildings, Reclamation of waste and tailings dumps, Monitoring of discharges
• Prospecting (Mineral Deposit)

  1. Prospecting, the search for ores or other valuable minerals, direct and indirect prospecting techniques employed

  2. Direct method of discovery: visual examination, geologic studies, precise mapping, structural analysis

  3. Indirect search: geophysics, geochemistry, geobotany

  4. Prospecting activity conducted by geologists, geophysicists, field samplers, drillers, and laboratory personnel

  5. Prospecting methods: Remote sensing tools, Ground prospecting
• Prospecting activity is largely conducted by geologists and geophysicists, assisted by field samplers, drillers, and laboratory personnel (for chemical assays)
• How prospecting is conducted and its cost can vary significantly, depending on whether a company is prospecting areas
• Tools for mineral prospecting

  • Remote sensing (satellite imagery), Geophysical surveys, Geological mapping, Geochemical surveys, Radiometric surveys
• Exploration generally shifts to surface and subsurface locations, using a variety of measurements to obtain a more positive picture of the extent and grade of the ore body
• Exploration


  Shifts to surface and subsurface locations, using a variety of measurements to obtain a more positive picture of the extent and grade of the ore body
• Exploration is commonly the longest and riskiest “stage” on the road to establishing a mine, and can take up to several years for each project
• For one successful prospect that will develop into a mine, many more will be abandoned without any further development
• Exploration activity is largely conducted by geologists and geophysicists, assisted by field samplers, drillers, and laboratory personnel (for chemical assays)
• How exploration is conducted and its cost can vary significantly, depending on whether a company is exploring areas
• Ground exploration

  1. Geological mapping

  2. GIS (Geographic Information System)

  3. Drilling (RAB, RC, diamond)

  4. Sampling (chip, rock, ….. etc.)

  5. Chemical assays
• Tools used for exploration depend on various factors such as the size and accessibility of the area, whether deposits are exposed at the surface or hidden, and the stage of exploration
• 3D Modeling Software's for Mining Sectors

  • Surpac
  • Minex
  • Whittle
  • GEMS
  • MineSched
  • PCBC
  • Vulcan
  • Leapfrog Geo
  • Micromine
• Exploration Results include results of outcrop sampling, assays of drill hole intersections, geochemical results, and geophysical survey results
• 3D Geological Modeling

  The 3D underground geological model for ore deposit structures interpolated from detailed surface geological map & cross-sections derived from downhole drilling data
• Mineral resource estimation has changed considerably in the past 25 years
• The fundamental key to a successful mineral project is resource estimation with a clear understanding of the resource geology and mining aspects of the deposit
• Mineral Resources categories

  • Inferred
  • Indicated
  • Measured
• Ore Reserves are those portions of Mineral Resources that, after the
• Mineral Resources


  Sub-divided, in order of increasing geological confidence, into Inferred, Indicated, and Measured categories
• Resource Estimation


  • Mineral Reserve