Drill-hole Spacing Optimizations in Grade-Control

• Author / Creator

  Gomes, Caio

• Final estimates at the grade-control (GC) stage of mining are built to maximize the correct classificationof mineable blocks. The costs include drilling, mining, and processing. When consideringdedicated GC drilling, Drill-hole spacing (DHS) optimization for profit balances the cost of estimationuncertainty and the cost of the drilling. The drilling amount is optimal when drilling less wouldincur large estimation costs and drilling more would incur large drilling costs.To support DHS optimization in GC, a DHS framework for regularly-spaced drill-holes is developedand evaluated. Aiming at increasing profit and going beyond regularly-spaced drilling, a secondDHS methodology is designed, where DHS from two phases are optimized. An automated workflowis developed that delivers the location of the final optimal GC samples in addition to optimal DHSdecisions.The methodology of DHS optimization for profit is investigated by considering geology, miningselectivity, spatial continuity, ore price, and other factors. Each factor is varied one at a time,and optimal DHS decisions and profit changes are recorded and summarized. Finally, the DHSframeworks are demonstrated on real data from a copper-molybdenum deposit.The research establishes a conceptual foundation and practical details for developing DHS optimizationfor final estimates in mining operations with dedicated drilling systems. The nested DHSframework can lead to improved results, but greater flexibility at the time of mining is required.

• Subjects / Keywords

  • geostatistics
  • drill-hole spacing
  • grade-control
  • mining
  • profit optimization
  • mineral resource estimation
  • mine geology

• Graduation date

  Fall 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-k1w8-4p57

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.