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24-MMP-A4 Mine Valuation and Mineral Resource Estimation · Undated paper

Question 14 of 19: Extending "Waste Mining" Scheduling Logic to Underground Development

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

Notes on this paper

EGBC National Exam — Mining and Mineral Processing Engineering, 09-MMP-A4 Mine Valuation and Mineral Resource Estimation, undated sitting. 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 (parts 1.1–1.5); 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, anisotropy, volume–variance relations); Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design (mine scheduling, NPV/valuation methods, stripping-ratio economics); Gentry & O'Neil, Mine Investment Analysis (Canadian mining taxation, CCA classes, smelter/refining contract terms, net smelter return); SME Mining Engineering Handbook, 3rd ed. (mineral exploration/evaluation stages, ore reserve classification); Guilbert & Park, The Geology of Ore Deposits (volcanogenic massive sulphide genesis); CIM Best Practice Guidelines and NI 43-101 (Canadian Securities Administrators).

Some question wording is assumed where the paper is unclear. Several tables in the paper do not reconcile arithmetically (the Q1.4.3 reserve table, the Q4 ore/waste schedule totals, the Q5.5 earnings-split percentages), and some sub-part mark values do not add to the question totals. This solution answers the conceptual and methodological content in full and works the self-consistent numeric sub-parts (NPV in 1.3, the nested variogram in 3.2, the depreciation schedule in 5.1, the NSV/NSR chain in 6.3–6.5), flagging every place an inconsistency is carried forward.

Question 4.5: Extending "Waste Mining" Scheduling Logic to Underground Development (3 marks)

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.

Yes — the underlying scheduling logic transfers directly, because both "waste mining" in an open pit and "development" in an underground mine share the same defining feature: non-revenue-generating work that must be completed ahead of and in a fixed ratio to ore production before that ore can be extracted. The open pit's North-West-Corner, quota-driven, "waste-ahead-of-ore" scheduling method maps onto underground development as "development-ahead-of-stope" scheduling: development metres (drifts, ramps, raises, sill/crown pillars) take the place of waste tonnes, and stope/ore tonnes take the place of open-pit ore tonnes, with the same rule that a stope cannot be mined until its access development is complete, exactly as an ore bench cannot be mined until the waste above it is stripped. The specific "development ratio" (development metres per tonne of ore, the underground analogue of the stripping ratio) varies strongly by method: sublevel/longhole open stoping requires comparatively low development intensity per tonne (large stope volumes accessed by relatively few sublevel drifts), similar to a low-stripping-ratio pit year; cut-and-fill and shrinkage stoping require continuous, ongoing development-like access work throughout extraction (backfill/access drives advancing with the stope face), more analogous to a sustained moderate stripping ratio every period rather than a front-loaded one; and block/panel caving requires an unusually large, front-loaded capital development campaign (undercut, drawpoints, extraction level) before any ore is drawn at all, closely analogous to the open pit's heavy pre-production stripping years. In every case, the same fleet-smoothing and priority-sequencing logic from 4.4.1 applies: a planner should sequence development to avoid both idle production capacity (development lagging too far behind) and unnecessarily front-loaded capital spend (development racing too far ahead), just as waste stripping is balanced against ore production in the open pit case.