A new generic open pit mine planning process with risk assessment ability
Loading...
Files
Date
2016-12-17
Authors
Mai, Ngoc Luan
Erten, Oktay
Topal, Erkan
Journal Title
Journal ISSN
Volume Title
Publisher
International Journal of Coal Science and Technology
Abstract
Conventionally, mining industry relies on a deterministic view, where a unique mine plan is determined based on a single resource model. A major shortfall of this approach is the inability to assess the risk caused by the well-known geological uncertainty, i.e. the in situ grade and tonnage variability of the mineral deposit. Despite some recent attempts in
developing stochastic mine planning models which have demonstrated promising results, the industry still remains sceptical about this innovative idea. With respect to unbiased linear estimation, kriging is the most popular and reliable deterministic interpolation technique for resource estimation and it appears to remain its popularity in the near future. This paper presents a new systematic framework to quantify the risk of kriging-based mining projects due to the geological uncertainties. Firstly, conditional simulation is implemented to generate a series of equally-probable orebody realisations and these realisations are then compared with the kriged resource model to analyse its geological uncertainty. Secondly, a production schedule over the life of mine is determined based on the kriged resource model. Finally, risk profiles of that production schedule, namely ore and waste tonnage production, blending grade and Net Present Value (NPV), are
constructed using the orebody realisations. The proposed model was applied on a multi-element deposit and the result demonstrates that that the kriging-based mine plan is unlikely to meet the production targets. Especially, the kriging-based mine plan overestimated the expected NPV at a magnitude of 6.70% to 7.34% (135 M$ to 151 M$). A new multivariate conditional simulation framework was also introduced in this paper to cope with the multivariate nature of the deposit. Although an iron ore deposit is used to prove the concepts, the method can easily be adapted to other kinds of mineral deposits, including surface coal mine.
Description
Keywords
open pit mine planning, geological uncertainty, multivariate conditional simulation, grade/tonnage curves, Research Subject Categories::TECHNOLOGY::Civil engineering and architecture::Geoengineering and mining engineering
Citation
Mai Ngoc Luan et al.(>2), 2016(December 17), A new generic open pit mine planning process with risk assessment ability, International Journal of Coal Science and Technology, pp.407–417