24-MMP-A4 Mine Valuation and Mineral Resource Estimation · December 2014
Question 26 of 27: After-Tax Cash Flows and NPV
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, 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 7.1: After-Tax Cash Flows and NPV (8 marks)
Purchase (capital) cost = 0.7M at Year 0; salvage value = 0.1M realized at completion of mining (end of Year 4); cost of capital i = 10%.
Find. After-tax cash flow (ATCF) for each of Years 1–4, and the project NPV.
Cash-flow diagram: 0.7M capital outflow at Year 0, after-tax cash inflows Years 1–4 (Year 4 includes the 0.1M salvage).
Approach. Compute ATCF = Revenue − Operating cost − Tax for each year (adding salvage in Year 4), then discount each year's ATCF at 10% and sum, netting off the Year-0 capital cost.
Year 1–3 ATCF. $$ATCF_1=1.000-0.400-0.159=0.441\text{M};\quad ATCF_2=1.000-0.400-0.1615=0.4385\text{M};\quad ATCF_3=1.000-0.400-0.1656=0.4344\text{M}$$
Year 4 ATCF (including salvage). $$ATCF_4=(1.000-0.400-0.1684)+0.100=0.4316+0.100=\boxed{0.5316\text{M}}$$
Discount each year's ATCF at i=10%. $$PV_1=\frac{0.441}{1.10}=0.4009\text{M};\ PV_2=\frac{0.4385}{1.10^2}=0.3624\text{M};\ PV_3=\frac{0.4344}{1.10^3}=0.3264\text{M};\ PV_4=\frac{0.5316}{1.10^4}=0.3631\text{M}$$
Net present value. Sum the discounted cash flows and subtract the Year-0 purchase cost: $$NPV=-0.700+(0.4009+0.3624+0.3264+0.3631)=-0.700+1.4528=\boxed{0.753\text{M CDN}}$$
Year
ATCF
PV @ 10%
1
0.4410M
0.4009M
2
0.4385M
0.3624M
3
0.4344M
0.3264M
4 (incl. salvage)
0.5316M
0.3631M
NPV
0.753M CDN
Check
NPV is strongly positive (≈108% of the 0.7M purchase price) on the exam's own given cash flows — the acquisition is clearly justified at a 10% cost of capital under this data; a candidate should sanity-check that the given revenue/cost/tax figures are what the exam intends before committing to a strategic recommendation on such a large margin.