In the last article Hardrock Mining Drill Rig Selection – Part One, we introduce field application for Mining Drill Rig and the target for all application(Minimum Cost and Maximum Output), in today’s blog, we will give more detailed suggestions how to select proper rig for specific application.

Operations Priority

  • Focus on budgets and invoice costs
    • Buys the largest hole diameter and the cheapest drill rig one can find or subcontracts the drilling
    • Miminize moveability and versatility, service, spare parts, reliability, operational costs
    • Proper criteria for us, Surface Study Program to get on right track.
  • Balancing budget imperatives with applications issues
    • Committee or application consensus drives selection
    • Eliminate drill alternatives that don’t fit.
    • Support, spare part issues. Create ” a standard” (spec, controls etc. for our advantage).
    • Automation options to create enhanced value with low cost.
  • Focus on lowest cost/ton operating scenario
    • Creates a working operating economic cost model that demonstrates full process costs with internal and external factors
    • Surface Study Program, Plant designer program, Sim Quarry.
    • Run scenarios with different rigs and hole sizes.
    • SanRemo, TIM3D and connections to existing mine automation systems to be monitored as a part of the process.
    • Hole quality and it’s significance Lifetime support

Selecting the drill hole diameter

  • Largely depends on desired production rate and rock drillability as well as rock properties
  • Some factors restricting
    • Required fragmentation size
    • Ground vibration restrictions when blasting
    • Selective rock excavation
  • Smaller holes -> lighter explosives -> better fragmentation
  • Lafarge Exshaw Cement Quarry
    • Annual production 1,6 Million Tons
    • Rock type limestone/dolomite (density 2 600 kg/m3)
    • Primary gyratory crusher 1370 mm with opening 150 mm

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  • Mining drilling hole size and fragmentation
    • Larger holes lead to coarser fragmentation
    • Deeper sub-drilling and larger floor damage
    • Thicker stemming and amount of oversize, fly rocks and wall/face damage

 

 

 

 

 

 

 

 

 

 

 

 

  • Selecting the drill hole diameter Mining drilling as recommended in chart below

 

Choosing Right Rig for Right Purpose from HARDROCK

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