24-MMP-A5 Surface Mining Methods and Design · December 2014
Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)
EGBC National Exam — Mining and Mineral Processing Engineering, 09-MMP-A5 Surface Mining Methods and Design, 2014-Dec. 3 hours duration, closed book; one hand-written 8.5×11 inch reference sheet and an approved Casio or Sharp calculator permitted. Question 1 is compulsory (40 marks, all seven parts 1.1–1.7); a candidate then selects THREE of Questions 2–7 (each worth 20 marks).
Reference texts: Hartman & Mutmansky (eds.), SME Mining Engineering Handbook, 3rd ed. (dragline stripping systems, truck-shovel productivity, mine dewatering, mine cost estimation); Hustrulid, Kuchta & Martin, Open Pit Mine Planning and Design, 3rd ed. (block-model economics, floating/moving-cone algorithm, the Lerchs–Grossmann graph-theoretic pit-optimization method); Kennedy, B.A. (ed.), Surface Mining, 2nd ed., SME (dragline range-diagram geometry, stripping methods); Lerchs, H. & Grossmann, I.F. (1965), “Optimum Design of Open-Pit Mines,” CIM Bulletin, 58, 47–54; Mular, A.L. & Poulin, R. (1998), CapCosts: A Handbook for Estimating Mining and Mineral Processing Equipment Costs, CIM Special Volume 47 (parametric open-pit capital-cost formulae used throughout Question 7).
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.
Cost index. A cost index is a dimensionless number, tracked over time against a fixed base year, that captures how the cost of a representative “basket” of labour, equipment, and materials for a given class of project has escalated – it lets an estimator scale a KNOWN historical project cost to a CURRENT-year estimate by simple ratio: $$\text{Cost}_{now}=\text{Cost}_{base}\times\dfrac{\text{Index}_{now}}{\text{Index}_{base}}$$ without re-deriving the estimate from first principles.
Two examples. (i) The Marshall and Swift Mining and Milling (M&S M/M) cost index (Question 1.7.1) – a composite index specific to mining/milling capital equipment and construction, the one used to escalate the Mular & Poulin 1998-dollar formulae of Question 7 to a current-year figure. (ii) A general engineering construction index such as the Chemical Engineering Plant Cost Index (or the Engineering News-Record Construction Cost Index) – broader, tracking general process-plant/construction labour and materials rather than mining-specific equipment, useful for the infrastructure and building components of a mine cost estimate that are not well represented by a mining-specific basket.
Problems applying one index to all cost sectors. Every index is built from a FIXED weighting of labour, steel, energy, and specific equipment types representative of a “typical” project when the index was defined; individual cost centres do not escalate at the same rate as that blended average – energy-intensive centres (drilling, hauling fuel) can spike well above the index during an oil-price shock while labour-dominated centres move with regional wage settlements, and equipment-heavy centres (shovels, trucks) can escalate very differently again as manufacturers adopt new technology (Question 7.7 finds exactly this: the escalated 1998 shovel/truck costs likely under-predict 2014 actual costs). A single index also does not capture REGIONAL cost differences (remote/heavy-terrain sites, per Question 7's own site) or technology substitution (a newer, more productive machine class replacing the one the index basket was built around). Applying one index uniformly therefore systematically mis-states some cost sectors even while it is approximately right on average.
