1758 A STOPE‑SCALE MULTIPHYSICS FRAMEWORK FOR OPTIMISING IN‑PLACE RECOVERY OF COPPER *Zhihe Wang1, Chaoshui Xu1, Peter Dowd1, Peter Dare-Bryan2, Armineh Hassanvand2, David Hunter3 1School of Chemical Engineering, Adelaide University, Australia, (*Presenting author: zhihe.wang@adelaide.edu.au) 2Orica Australia, Australia 3Core Resources, Australia ABSTRACT As shallow mineral resources are depleted, mining is moving to deeper, lower-grade, and more complex deposits, creating economic and technological challenges. As a low-cost and low-environmentalfootprint mining technique, underground leaching is gaining increasing attention for low-grade deposits. In hard-rock formations, In-Place Recovery (IPR) has can be both economically viable and technically feasible for extracting minerals from low-grade orebodies. With IPR, stopes are blasted to enhance permeability, and a lixiviant is applied to dissolve target minerals. The pregnant leach solution is collected underground for processing, thereby reducing energy consumption, land use, waste generation, and operating costs. To assess IPR performance, this study presents a stope-scale multiphysics modelling approach that couples variablysaturated fluid flow, lixiviant transport, and chemical reaction. This enables physics-based simulation of an IPR operation to predict both lixiviant migration and mineral recovery under varying ore mineralogy, blasted ore size distribution, irrigation rate, lixiviant dosing, and stope geometry. Using ore samples from an Australian mine site, key material properties measured in the lab were used as model input to simulate IPR in a single stope over a 12-month period. Multiple cases with different leaching parameters were examined to assess the leaching performance under various conditions. The outcomes of this study highlight the model's capability for IPR feasibility assessment and operational optimisation. KEYWORDS Sustainable mineral extraction, In-Place Recovery, low-grade copper, multiphysics simulation 1. INTRODUCTION Unlike conventional heap leaching where blasted ore is moved to the crusher circuit on the surface, In-Place Recovery (IPR) uses high-intensity blasting to generate permeable broken stock within a stope. Then, lixiviant is applied to the blasted ore, dissolving target minerals as it percolates through the stope, and the pregnant leach solution (PLS) is collected for subsequent processing, as shown in Figure 1 (Ghorbani et al., 2016; Hassanvand et al., 2025a). IPR can potentially be an effective method to extract minerals such as copper from low-grade and hard-rock deposits with minimal ore transportation and surface infrastructure (Dare-Bryan and Hassanvand, 2023; Estay et al., 2023).To achieve successful IPR implementation, it is important to be able to model accurately the operation process to assess project feasibility, mitigate risks, optimise designs, and forecast recovery. For the past few decades, substantial modelling works have been done to predict copper recovery for heap leaching (Ferrier et al., 2016; Marsden and Botz, 2017). In these works, column test results are often fitted with empirical or semi-empirical models based on the shrinking core concept to capture the total copper recovery change with time. The fitted models are then used to predict recovery for the actual heap leaching
RkJQdWJsaXNoZXIy MTM0Mzk2