24-MMP-A4 Mine Valuation and Mineral Resource Estimation · May 2013
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, 2013-May. 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, selective mining units); Gentry & O'Neil, Mine Investment Analysis (Canadian mining taxation, smelter/refining contract terms, net smelter return); SME Mining Engineering Handbook, 3rd ed. (mineral exploration and evaluation stages, ore reserve classification).
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.
Price participation. "Price participation" is a smelter-contract clause under which the metal price used to settle payment is not fixed at the moment of shipment but is instead determined by the average market price (e.g. LME cash settlement) over an agreed quotational period that can extend before, during or after the shipment date – commonly the average of the month of arrival, or the average of the month following arrival, at the smelter. Because the market price is only known once the quotational period ends, both the mine and the smelter carry price (and sometimes currency) exposure between the shipment date and final settlement, and the contract sets provisional payment terms (typically ~90% of provisional value paid on shipment, with a final adjustment once the true quotational-period average price and final assays are known) to manage that exposure. In effect, "price participation" is the mechanism by which the concentrate seller shares in whatever the market does during the negotiated pricing window, rather than locking in the spot price on the day of shipment.
Why a smelter contract must be secured before opening a mine. A medium-cap producer typically has no smelting or refining capacity of its own, so its entire revenue stream depends on a third-party smelter agreeing, in advance, to accept its concentrate at defined treatment/refining charges, penalty schedules and payability terms. Without that contract in hand the company cannot forecast net smelter return, cannot present a bankable cash-flow model to lenders, and risks having a finished mine with no committed offtake for its product – smelters have finite throughput capacity that is booked years in advance, so waiting until the mine is built is far too late.
Comparison with oil-sands pipeline capacity. Yes, the situations are directly analogous: an oil-sands producer likewise has no independent means of monetizing its bitumen without secured, contracted pipeline (or rail) takeaway capacity to a refining/upgrading market, and pipeline capacity is similarly finite and booked well in advance. In both cases the mine/well site is only the first link of a supply chain whose downstream capacity (smelter or pipeline) is owned by someone else, is capacity-constrained, and must be contractually secured before capital is committed – failure to do so in either industry leaves the producer exposed to distressed spot-market terms (heavy discounting, or simply no buyer) once production starts.
