Optimization In Mining

Whittle Programming Pty Ltd. (Melbourne, Australia)

THREE-D

Finds the three dimensional open pit outline which maximizes the total undiscounted cash flow. It can be used for mines with a life of up to three years. Beyond three years the discounting of future cash flows starts to affect the ultimate pit outline which has the highest Net Present Value.

FOUR-D

Deals with the effect of time on the value of cash flows. It also allows rapid simulation of the mine life for different mining sequences and economic scenarios. Four-D should be used rather than Three-D when the mine life is expected to be more than three years.

OPTI-CUT

Optimizes the cut-offs to be used over the life of a mine so as to maximize Net Present Value.

FOUR-X

Analyses and forecasts the optimal pit for long term projects. There is a single element version and a multi-element version. It has all the facilities of Four-D, and operates in a similar way. However, unlike Four-D it is not limited to handling just one product. Four-X handles up to ten "elements", where each may or may not be a product and each may or may not be the subject of a cut-off. Costs and recoveries can vary with the grade of any of the elements. FOUR-X can be used for project scoping, for feasibility studies, for sensitivity work, for risk analysis, for scheduling, and for deciding where to drill.