24-MMP-A4 Mine Valuation and Mineral Resource Estimation · December 2018
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, 2018-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 1.1–1.8); candidates then select THREE of the five optional Questions 2–6 (20 marks each) to complete the paper.
Reference texts: Isaaks & Srivastava, An Introduction to Applied Geostatistics (variogram modelling, kriging, anisotropy); Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design (mine valuation, NPV/IRR and cut-off grade methodology); Gentry & O'Neil, Mine Investment Analysis (smelter/refining contract terms, net smelter return, taxation and risk); Guilbert & Park, The Geology of Ore Deposits, and Evans, Ore Geology and Industrial Minerals (VMS/SEDEX and porphyry deposit models); 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.
VMS lenses in the Canadian setting (Bathurst Camp, and historically Noranda-camp deposits) are typically STEEPLY DIPPING, structurally deformed (folded/faulted by later orogenesis) and moderate in size, which favours selective UNDERGROUND methods — longhole open stoping with backfill, or cut-and-fill where grade continuity is irregular — rather than open pit, because the deformed, discontinuous geometry makes a large open pit's stripping ratio uneconomic beyond shallow oxide caps. Selective underground mining costs more per tonne (typically several times an equivalent open-pit unit cost) but preserves grade by avoiding dilution of a relatively narrow, high-grade lens.
SEDEX deposits such as Sullivan are commonly larger, more TABULAR/gently-dipping and can be substantially thicker, which historically supported a combination of methods over the mine's life — Sullivan itself progressed through cut-and-fill, and large-scale mechanized methods including trackless mining and cemented backfill as the operation matured — generally achieving somewhat LOWER unit operating costs than a comparably-graded VMS vein-style deposit because of the larger, more regular stoping panels achievable in a tabular body, though still requiring underground access once the deposit passes below economic open-pit depth. In both cases, Canadian operating costs are strongly influenced by depth (ventilation, hoisting, ground support), remoteness (power and logistics, especially for northern VMS camps), and the selectivity required to avoid diluting a relatively narrow orebody with barren wall rock.
