Joint stochastic optimisation of short a

A new multistage stochastic mine production scheduling approach is developed and tested in a large operating gold mine. The method incorporates short scale orebody information via grade control data which are not available at the time of production scheduling. The approach consists of four stages: the first stage simulates future grade control data using exploration data; the second updates orebody models through conditional simulation; the third formulates a stochastic programming mine scheduling that maximizes net present value (NPV) and minimizes deviations from production targets; and the fourth quantifies the risk and reports on the production schedules. The application of this approach resulted in an additional 3.6 Mt of ore and 2.6 Mg of metal, with a cumulative NPV on average 7 million AUD higher than a conventional schedule. Furthermore, it demonstrated compliance between short- and long-term production schedules, increasing the probability of meeting production targets while enhancing productivity. These findings suggest that the proposed approach is practical and significantly beneficial, especially in the capital-intensive context of mining operations.