Name, Surname Number MAD 307 EVALUATION OF ORE DEPOSITS MID-TERM EXAM II 26/12/2016 20 1) Explain the terms extension variance, estimation variance and dispersion variance. 20 2) Define the mineral resource and its categories. 20 3) Estimate the grade of the point D from A and B using kriging when the variogram model for grade is spherical with parameters C=100, a=500m and z(A)=10% and z(B)=16%. A 100m D-? 300m B 20 4) Consider the following drilling pattern in which the thickness of drill holes has a mean of 5m and variance of 20. The variogram model for thickness is linear (y(h)=0 for h=0 and y(h)=h for h>0). The specific gravity of ore is 2.4 ton/m. Estimate the tonnage and construct 95% confidence interval for the true tonnage. H(1.1) 0.7652-1, F(1, 1) = 0.5213 / a=2H (0.5 1,0.5+1)-F(LI) = F(II) 56 45 35 + Var(t) $2 25 (+ +0.0609- N N 15 B 5 15 25 45 55 20 5) We want to mine a coal panel with size of 500m x 1000m by strip mining. For this purpose the blocks with size of a) 250m x 100m or b) 100m x 100m will be used. When the variogram of the coal is spherical with parameters Co-5, C=15 and a=1000m, find the block size that will give the smallest variability. () = P(V.V) - F(v, v) F(0.5, 1.0) 0.541, F(0.1, 0.2)=0.12, F(0.25, 0.1)=0.14, F(0.1,0.1)=0.078, F(0.2, 0.2) 0.155, F(0.5, 0.2)=0.28