Direct block scheduling under marketing uncertainties

Abstract

Mineral projects are composed of geological, operational and market uncertainties, and reducing these uncertainties is one of the objectives of engineering. Most surveys assess the impact of geological and operational uncertainties on the mining planning. The objective of this work is to study the impact of market uncertainty on the mineral activity. The influence of iron ore price simulation on mining sequencing will be evaluated. The price of iron ore has random behavior that is best represented by the Geometric Brownian Movement system. This study analyzed the historical series of iron ore in order to determine the percentage volatility and drift. Traditionally, a constant and deterministic price is used for the ore mined in all periods of a mineral project. The direct block scheduling methodology was adopted because it is able to apply the appropriate financial discount factor to the simulated probabilistic price. The proposed methodology was able to quantify the market uncertainty.

Optimum mine production rate based on price uncertainty

“…Low operating costs and high production capacities are the basis of economies of scale. Burgarelli et al (Burgarelli et al, 2018) analysed the impact of the price on extremely sensitive iron ore deposit and cut off grade policy behavior showed that a change in ore price altered the destination can reach 45% of the scheduled blocks due the deposit behavior. This change can affect the haul distance and the mine cost.…”

Analysis of the impacts of slope angle variation on slope stability and NPV via two different final pit definition techniques

“…Treating uncertainties is one of the mainstream paths in recent mine planning studies. There are numerous research studies with different approaches to different sources of uncertainties, such as Burgarelli et al (2018), Carvalho et al (2018) and Ramazan and Dimitrakopoulos (2018). The first study presented the impact of market uncertainty by evaluating the influence of iron ore price simulation on mining sequencing using the DBS methodology; the second, compared models in terms of sensitivity to the spatial variability of the ore grades using both the LG algorithm and the DBS; and the later, integrated deposit variability and uncertainty directly in the production scheduling optimization process.…”

Impacto econômico da lavra de barragens

“…Durante a realização, foram encontradas dificuldades na estacionalização de massas na alimentação da usina, pois o software não levava em consideração o decapeamento que deve ser realizado nas frentes de lavra, extraindo assim muito material em determinados períodos e quase nenhum em outros. Após a aplicação de uma técnica denominada pré-stripping o problema foi solucionado e chegamos à conclusão de que, no cenário escolhido, utilizando determinados parâmetros, a utilização da lavra da barragem/pilha ocasionou não uma queda no valor presente líquido (VPL) do empreendimento, mas sim um leve aumento (Burgarelli, et al 2018) (Souza & Melo 2014).…”