Strategic mining options optimization： Open pit mining, underground mining or both

• Published in: International journal of mining science and technology 2016-11, Vol.26 (6), p.1065-1071
• Main Authors: Ben-Awuah, Eugene, Richter, Otto, Elkington, Tarrant, Pourrahimian, Yashar
• Format: Article
• Language: English
• Subjects: Concurrent; MILP; Mining options optimization; Mixed Integer Linear Programming (MILP); Open pit; Open stope; Underground; 优化器; 地下开采; 投资回报; 挖掘; 混合整数线性规划; 露天开采; 露天矿开采
• ISSN: 2095-2686
• DOI: 10.1016/j.ijmst.2016.09.015

Near-surface deposits that extend to considerable depths are often amenable to both open pit mining and/or underground mining. This paper investigates the strategy of mining options for an orebody using a Mixed Integer Linear Programming （MILP） optimization framework. The MILP formulation maximizes the Net Present Value （NPV） of the reserve when extracted with （i） open pit mining, （ii） underground mining, and （iii） concurrent open pit and underground mining. Comparatively, implementing open pit mining generates a higher NPV than underground mining. However considering the investment required for these mining options, underground mining generates a better return on investment than open pit mining. Also, in the concurrent open pit and underground mining scenario, the optimizer prefers extract- ing blocks using open pit mining. Although the underground mine could access ore sooner, the mining cost differential for open pit mining is more than compensated for by the discounting benefits associated with earlier underground mining.