Goldilocks: value of information for geoscience in bulk mineral mining

摘要

Comparing resource knowledge across mineral assets, combined with complexity in the decisions and processes supported by this knowledge, makes it difficult to prioritise geoscience measurement programs such as drilling or airborne geophysics in a multi-commodity portfolio. Value of Information (VOI) is a well-known concept in decision science, with potential to quantify a comparable value of geoscience programs across different assets and time horizons for use in planning and prioritization. Calculating VOI for candidate geoscience programs has two main steps. First, representation of resource uncertainty by multiple equi-probable realisations of the resource. This is achieved through utilization of previous reconciliation data and application of geostatistical techniques such as conditional simulation. For each realisation a plan is created and optimised to that realisation, and simulation of how that scenario will play out in the current base plan. Comparison of these results shows which decisions will deliver more value with better resource definition. Through examination of how extraction decisions change under different resource scenarios, it is possible to gain insight into the optimum timing and intensity of geoscience activity. This is enabled by both the ability to generate a representative distribution of resource scenarios and an internally developed mine planning platform capable of running multiple mine plans in compressed timeframes.Both Value of Perfect Information (VOPI) and Value of Imperfect Information (VOII) have been calculated for strategic and tactical geoscience programs showing the effect of uncertainty on individual mine planning decisions such as orebody sequencing, quality scheduling, and fleet estimation. This study supports that idea that quantification of resource definition through application of the VOI method to bulk mineral mining has potential to (1) drive efficiencies in geoscience planning and (2) increase mine plan value by reducing outcome uncertainty to an acceptable level.