🤖 AI Summary
This study addresses the complex decision-making challenges in lithium mining, where production planning must contend with multiple uncertainties—including geological reserves, market demand, and price volatility—and trade-offs among diverse extraction technologies. Traditional approaches struggle to simultaneously optimize economic and environmental objectives under such dynamic conditions. To overcome this limitation, the paper proposes a novel multi-objective partially observable Markov decision process (POMDP) framework that jointly incorporates price and demand uncertainty alongside multiple lithium extraction methods. By leveraging belief-state planning, the model dynamically optimizes key decisions such as exploration timing, mine commissioning, and technology selection. Experimental results across various price evolution models and deposit scenarios demonstrate that the proposed approach significantly outperforms human-designed heuristic policies, achieving higher demand fulfillment rates while delivering a superior balance between economic returns and environmental impact over the full project lifecycle.
📝 Abstract
Decision making in lithium production is challenging, whether from an investor's perspective or a strategic production standpoint. Determining which mines to open and when to open them involves not only geological and price uncertainties, but also complexities around the choice of extraction method, from direct lithium extraction to hard rock mining. Prior work explored models of this problem and different methods to optimize mining decisions; these models did not account for uncertainty in pricing, uncertainty in demand, or different mining technologies to extract lithium. Incorporating different pricing models and extraction technology into these models enables more robust strategies for determining not only when and where to open a mine, but also which method of production to pursue. We frame the problem as a partially observable Markov decision process (POMDP) and solve using belief state planning methods to get optimal decision making. In our study, we show that POMDP solvers outperform human inspired heuristics by dynamically adapting to shifting lithium price regimes (static, linear, exponential, and stochastic) through belief state planning and explicit uncertainty management. By optimally sequencing exploration, production, and technology choice, the framework achieves higher demand fulfillment and more balanced economic environmental outcomes over the projects lifetime in all different pricing and deposit scenarios.