Geostatistical Modeling for Grade Control and Long Range Models

• Author / Creator

  Amihere, Norris

• In general, less than one billionth of the volume of a deposit is sampled before production decisions. The grades and other rock properties are estimated in the unsampled volume. The success of a mine is dependent on accurate grade control. The grade control process establishes the final planned destination of mined material, directly influencing the operation’s profitability. Mistakes at this stage are costly and irreversible. Resource models are considered long-term when used for
  long-term mine planning; an example is a Life of Mine (LOM) plan. Long-term models are based on widely-spaced drilling, which is gradually filled in as the project advances. Long-term models provide estimates of tonnage and grade for each period involved through to the end of the life of the
  mine. Long-term models are designed to estimate what will be achieved during grade control with acceptable accuracy.
  Geostatistical modeling is challenging because of the geological variability/uncertainty in the grades. For example, when material needs to be directed to various stockpiles or treatment facilities, the procedure is frequently complicated by the need for numerous classifications. Grade control programs aim to minimize the misclassification of material, while the primary focus of long-term models is on the accuracy of estimated recoverable resources awaiting more data at the time of grade control. The prediction goals differ for grade control and long-term modeling; therefore, the appropriate
  geostatistical techniques and parameter setups differ. For this research, geostatistical models are generated through the following techniques: (1) Ordinary Kriging, (2) Expected sequential Gaussian Simulation, (3) Localized Uniform Conditioning, and (4) Localized Sequential Gaussian Simulation. The expected profits from realizations are demonstrated with a series of examples. The appropriate
  modeling techniques and parameter setups for grade control and long-term models in the presence
  of geological uncertainty are demonstrated and evaluated.

• Subjects / Keywords

  • Modeling
  • Grade control
  • Kriging
  • Grade Tonnage
  • Long term
  • Cutoff
  • Geostatistics

• Graduation date

  Fall 2023

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-1fz9-8k98

• 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.