Simulating Li-Ion Extraction: A Reservoir-Scale Feasibility

The escalating demand for lithium-ion batteries prompts exploration into efficient lithium production methods. Lithium, prevalent in brine, igneous, and sedimentary rocks, faces surging demand and prices. While brine remains a common source, growing interest in ores arises due to market dynamics. Spodumene, a major lithium-bearing mineral, poses challenges due to its resistance to industrial acids. Traditional methods involve converting α-spodumene to β-spodumene through high-temperature processes, hindering solution mining. Recent studies propose direct extraction using mixed acids. This research focuses on spodumene, assessing the feasibility of solution mining with a proposed mixed acid. Numerical simulations predict lithium-ion production, revealing challenges in deposits with limited acid injection feasibility. Artificial fractures prove crucial in deposits without natural fractures. Deeper deposits yield more lithium ions, correlating with dissolution rates and pressure differentials. Simulator outcomes reveal disparities, highlighting the need for optimized acid injection schedules. This study underscores the current challenges in applying the solution mining method to lithium-bearing deposits and emphasizes the need for further acid treatment optimization to achieve comparable productivity in the industry. The research contributes valuable insights for the future of sustainable lithium production. 1. INTRODUCTION In recent years, the demand for lithium-ion batteries as the next-generation power source for achieving a sustainable society has been expanding, and the consumption of lithium ions, the raw material for these batteries, is on the rise (Meng et al., 2021). Lithium is widely distributed in nature. It is found in brine (52-66%), igneous rocks (25-35%), and sedimentary rocks (8-13%), with brine being predominantly utilized in commercial production due to cost advantages (Reich et al., 2023; Zhao et al., 2023). The recent increase in demand for lithium has led to a rise in lithium prices, prompting a renewed interest in lithium production from ores. Among various lithium-bearing minerals such as spodumene, lepidolite, hectorite, and jadarite. Spodumene stands out as a major ore responsible for approximately 90% of lithium production from sources other than brine (Meng et al., 2021). In its natural state, spodumene exists as the α-phase in pegmatite deposits, and this α-spodumene exhibits strong resistance to acids commonly used in industrial plants (Aylmore et al., 2018; Li et al., 2019). Therefore, the extraction process for lithium ions from spodumene typically involves converting the α-Spodumene present in the ore into the more chemically reactive β-Spodumene phase through processes such as calcination or roasting (Meng et al., 2021). The necessity for calcination at temperatures exceeding 1000°C has been a hindrance to applying solution mining to lithium production (Aylmore et al., 2018; Salakjani et al., 2020). However, recent studies suggest that the direct extraction of lithium ions from α-spodumene is possible by using mixed acids, such as HF/H2SO4, CaF/HeSO3, and CaF/NaOH (Guo et al., 2017; Kuang et al., 2012).