Incorporating stochastic correlations into mining project evaluation using the Jacobi process

Uncertainty is an important phenomenon in mine project evaluation. Recovery, grade, commodity price, discount rate, and operating costs are highly uncertain variables. Given that uncertainties cannot be fully eliminated, mining companies focus on assessing risks associated with uncertainties. Mining projects generally encompass 10–50 years, and the evolution of uncertain parameters over this long time period is also uncertain. Since the future cannot be predicted, one way to deal with uncertainty is to create probable images of reality through simulation. When simulating multiple uncertain variables over time, an immediate problem is how to handle correlations among uncertain variables because the correlations themselves are uncertain variables. In this paper, the Jacobi process is used to treat the correlations stochastically. A case study was implemented in a mine project evaluation (e.g., net present value and option pricing), in which the gold prices and the US interest rates were considered as correlated uncertain variables. The correlations among uncertain variables significantly affected the value of the mining project. The Jacobi process can be used as a tool to increase the performance of mine project evaluation.