Mineral Economics, Mine Planning, Systems Engineering · Mine Planning · 2 marks · Numerical answer
The exploratory boreholes and their influence polygons are shown. With equal density assumed, estimate average deposit grade in percent to two decimals.
Weight each interval grade by interval thickness and polygon area. D1 contributes area0.02 times(6×63+6×66); D2 contributes0.03 times(6×60+4×64); D3 contributes0.04 times(8×64+7×62). Divide their sum by0.02×12+0.03×10+0.04×15. The result is62.98%. Equal density cancels, while unequal thicknesses must remain in the weights.
