Geoscience Reference
In-Depth Information
Fig. 14.43
Horizontal (left) and
vertical (right) variograms for
stepwise conditionally trans-
formed Zn, Pb, Fe, and Ba for
one domain
14.4.4
Profit Function
The kriging and simulation models provide the metal
grades. The metal recoveries for both Zn and Pb were calcu-
lated as Red Dog's five year average recovery (1998-2002)
based on Teck Cominco's financial report (Teck Cominco
2003). These were 83.6 % Zn recovery and 58.7 % Pb recov-
ery. The penalty functions, constructed to mimic the impact
of Fe and Ba on Zn recovery (decreasing functions on a scale
A simple profit function was developed to account for Zn
and Pb grades, recovery functions and metal prices. Penalty
functions to account for the impact of Ba and Fe on Zn re-
covery were incorporated. Pb recovery was considered con-
stant.
