来源：ScienceDirect
In the in-situ leaching of ionic rare earth ores, ineffective through-flow induced by ore body heterogeneity and suboptimal rinsing strategies constrain both extraction efficiency and mine environmental sustainability. This study employed an experimentally validated pore-scale numerical model, reconstructed from nuclear magnetic resonance imaging, to elucidate magnesium ion transport mechanisms and optimize rinsing operations for enhanced in-situ leaching performance. Simulation results showed a three-stage transport pattern in magnesium ion migration through heterogeneous ore pore networks, with advection, diffusion, and retention prevailing in sequence. Increasing the injection concentration from 0.06 to 0.48 mol/L increased the total magnesium output at the outlet by 916.55 %, aggravating the ineffective through-flow and severely compromising reagent utilization efficiency within the ore body. Critically, rinsing timing regulates magnesium ion displacement and retention by dynamically reshaping pore-scale concentration gradients. An optimal threshold for starting the rinsing operation was identified at 90 % of the peak rare earth concentration in the declining phase of the leaching curve. At this threshold, a balanced performance across multiple in-situ leaching indicators was achieved: 82 % of theoretical maximum rare earth recovery, 49.26 % magnesium utilization efficiency, rare earth output per unit injected magnesium of 1.20, yield-to-residual magnesium ratio of 2.45, and marginal rare earth gain of 2.30. This work proposed a simulation-guided dynamic rinsing strategy that offers a quantitative alternative to conventional empirical fixed liquid-to-solid ratios widely adopted in field practice. By elucidating the pore-scale “through-flow effect” and “displacement-retention” equilibrium, this study provides mechanistic insights into solute transport in heterogeneous ore bodies and a reference basis for process intensification and sustainable in-situ leaching of ionic rare earth ores.