Definition of an envelope and life-of-mine production schedule for block caving mines under grade and material flow uncertainty

Authors: Noriega, R; Pourrahimian, Y Download Paper Open access courtesy of:

This paper is hosted with the kind permission of the Universidad de Chile, Eighth International Conference & Exhibition on Mass Mining, 2020.

DOI https://doi.org/10.36487/ACG_repo/2063_74

Cite As:
Noriega, R & Pourrahimian, Y 2020, 'Definition of an envelope and life-of-mine production schedule for block caving mines under grade and material flow uncertainty ', in R Castro, F Báez & K Suzuki (eds), MassMin 2020: Proceedings of the Eighth International Conference & Exhibition on Mass Mining, University of Chile, Santiago, pp. 1025-1038, https://doi.org/10.36487/ACG_repo/2063_74



Abstract:
One of the main concerns when determining an economic envelope and life-of-mine schedule for block caving projects is the potential dilution of the estimated grade model. Material flow and mixing, which coupled with the uncertainty associated with the grade estimation process can generate unreliable mine plans and unrealistic economic valuations at early stages of the project. This paper presents a stochastic mathematical programming model to incorporate 3D material flow and mixing, through the concept of a cone of movement, and grade uncertainty, through sequential Gaussian simulation (SGS), into the definition of an envelope and life-of-mine production schedule for block caving mines. The model maximizes the NPV of the project under operational constraints and can be used on the resource model at early stages of the project. The result is a more robust mine plan that aims to meet production and grade quality targets over the different scenarios and a more realistic NPV estimation for the project.