Simultaneous stochastic optimisation of an open-pit gold mining complex with waste management

Abstract

Simultaneous stochastic optimisation manages risk and capitalises on the unique interactions that occur in a mining complex, where materials are transferred between mines, processors, stockpiles, and waste facilities to achieve a marketable product. Typically, when optimising the production schedule, the primary focus is to deliver valuable products to the market. However, this tends to ignore the environmental and economic impact of simplifying waste management requirements, including the storage and disposal of waste material. Stricter regulations and engineering requirements are transforming past mining practices to develop more sustainable operations. These transformations increase the financial cost of waste management and identify the requirement to integrate waste management into the production schedule. Additionally, misrepresenting the material uncertainty and variability associated with the amount of waste produced can impact, both, the stakeholders and the profitability of a mining complex. In this case study, a simultaneous stochastic optimisation approach is applied in a gold mining complex that integrates waste management into the longterm production schedule. The resulting schedule leads to a 6% increase in the net present value when compared to a conventional approach, while minimising the likelihood of deviating from production targets and ensuring permit constraints are satisfied.

Sustainable open pit fleet management system: Integrating economic and environmental objectives into truck allocation

“…Implementation of their proposed model on the case study shows that market uncertainty has a direct impact on all components of an open pit mining operation. Levinson and Dimitrakopoulos (2020) represent a simultaneous stochastic optimization model aiming to maximize the net present value (NPV) and minimize the risk of deviation from the production and environmental targets as well as the costs of mining and processing, deviations from waste disposal schedule, and the capacity of the stockpile. Authors implemented a meta heuristic solution method to solve the abovementioned problem.…”

Integration of strategic open-pit mine planning into hierarchical artificial intelligence

“…Decisions regarding exploration and sampling campaigns are beyond the scope of the MPSP as developed previously by Ferland (2014a, 2014b), Navarra, Grammatikopoulos, and Waters (2018), and others (Bienstock and Zuckerberg, 2010;Levinson and Dimitrakopoulos, 2019;Montiel and Dimitrakopoulos, 2015;Muñoz et al, 2018;Saliba and Dimitrakopoulos, 2019); although they could be part of the future work framed by Figure 3. Moreover, Navarra, Grammatikopoulos, and Waters (2018) give only a cursory discussion regarding strategic directives for linking rock types to concentrator operational modes, identifying data structure development as an avenue for incorporating downstream realism.…”

“…Any change in the sequence of extraction of the mining blocks modifies the activities downstream, including blending, processing, and transporting the processed material to output stockpiles or ports. This work seeks to extend the paradigm of the MPSP into a broader holistic view (Levinson and Dimitrakopoulos, 2019;Saliba and Dimitrakopoulos, 2019).…”

An Application of Simultaneous Stochastic Optimization at a Large Open-Pit Gold Mining Complex under Supply Uncertainty

“…However, it does not directly incorporate operating modes, transportation alternatives, or material supply from sources other than open-pit mines. This approach has been applied to different case studies incorporating market supply uncertainty [23], waste management [24], tailings management [25], and nonadditive attributes such as hardness [26]. In addition, the approach has been extended into a dynamic simultaneous stochastic optimizer to include capital investments [27,28].…”