24-MMP-A4 Mine Valuation and Mineral Resource Estimation · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Mining and Mineral Processing Engineering, 09-Mmp-A4 Mine Valuation and Mineral Resource Estimation, 2014-Dec. 3 hours duration; one handwritten 8.5×11 in reference sheet permitted (not an open-book exam); only approved Sharp or Casio calculators allowed. Question 1 is compulsory (40 marks, parts 1.1–1.7); candidates then select FOUR of the six optional Questions 2–7 (15 marks each) to complete the paper.
Reference texts: Isaaks & Srivastava, An Introduction to Applied Geostatistics (variogram modelling, kriging estimators, volume–variance relations); Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design (mine valuation, NPV and cut-off grade methodology, mineable reserves); Gentry & O'Neil, Mine Investment Analysis (Canadian mining taxation, smelter/refining contract terms, net smelter return); SME Mining Engineering Handbook, 3rd ed. (mineral exploration/evaluation stages, ore reserve classification); CIM Best Practice Guidelines and NI 43-101 (Canadian Securities Administrators).
Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.
The pseudo samples are discretization points placed at the centroid of each of the four quadrants of the block (a standard block-discretization grid used to numerically approximate the average sample–to–block covariance, since the true sample-to-block covariance is itself the average of the sample-to-point covariance integrated over every point inside the block). A 4-point (2×2) discretization is the coarsest practical grid and is only marginally adequate here: because the ranges of the fitted structures (from Figure 4.3, roughly 100–150 m in the regional component) are large relative to the 20 m block, the sample–to–point covariance barely changes across the block's own 20 m width, so a coarse 4-point grid introduces little discretization error for this specific geometry. For a smaller variogram range (comparable to or smaller than the block size) or a more anisotropic structure, however, 4 points would under-resolve the true within-block covariance variation, and a finer 4×4 (16-point) or 5×5 (25-point) grid would be needed for an accurate average.
