Mineral Economics, Mine Planning, Systems Engineering · Mine Planning · 1 mark · Multiple choice
Ore grades 58% and 62% Fe have net values₹4000 and₹4500/tonne. Net value varies linearly with grade. Waste mining costs₹1000/m³. Find the economic stripping-ratio relation SR in m³/tonne.
Value slope is(4500−4000)/(62−58)=125 rupees/tonne per percentage-point Fe. The intercept is 4000−125×58=−3250. Dividing value by 1000 rupees/m³ waste cost gives SR=−3.250+0.125Fe, A.