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.
A small copper producer has no captive smelting or refining capacity of its own, so its entire revenue stream depends on a third party buying and processing its concentrate. Without a signed offtake/smelter contract fixing treatment charges, refining charges, payables, penalty schedules and shipping terms before construction begins, the project cannot secure project financing (lenders require a bankable revenue stream), cannot forecast operating margin with any confidence (spot concentrate markets are thin and volatile, especially for a junior with no trading relationships), and risks having no buyer at all once concentrate is produced — smelters allocate capacity years in advance and prioritize established, contracted counterparties. The contract is therefore a precondition of financeability, not merely of marketing convenience.
A large, vertically integrated conglomerate producing on the order of ~20% of world copper supply is different in kind: it typically owns or controls its own smelting and refining capacity (or has such deep, diversified long-term relationships and trading volume that it can place concentrate on the spot/merchant market at will). Such a company can operate without a dedicated long-term smelter contract for a given mine because it can (a) toll its own concentrate through its own smelters, internalizing the treatment/refining margin rather than paying it away, (b) self-finance new mine development from balance-sheet cash flow rather than needing a bankable offtake contract to satisfy lenders, and (c) exert enough market influence/volume to sell concentrate on relatively favourable spot terms without long-term commitment. In short, contract dependence scales inversely with vertical integration and balance-sheet strength.
