• Sean Guidi

Optimization of Recovery from Heap Leach Facilities (HLF) utilizing Dynamic Systems Modelling

Sean Guidi, Forte Dynamics, CO, USA

Brendan Fetter, Forte Dynamics, CO, USA

Abstract paper on Heap Leach Facility Modeling from Sean Guidi and Brendan Fetter of Forte Dynamics. Forte Dynamics will be presenting on Optimization and Recovery from Heap Leach Facilities utilizing Dynamic Systems Modeling at the Heap Leach Solutions 2020 conference September 13-15, 2020, in Reno, Nevada (https://www.heapleachsolutions.ca/).


When looking to optimize recovery from Heap Leach Facilities (HLF), it is important to utilize dynamic systems models that track key process indicators (KPIs) related to heap leach operations. These models can be utilized to evaluate multiple scenarios and to optimize the project for recovery or for NPV. These models utilize a full mine-to-heap approach to understand how variations in mine plans and HLF operations impact recovery and project NPV. These models incorporate best practices for optimization; evaluating changes of the mine plan, ore placement, changes in PSD, and changes in planned leaching operations.

This discussion will focus on best practices utilizing dynamic systems models for optimization of project using a mine-to-heap modelling approach. Additionally, this will include discussion on integration of operational data for enhanced planning and forecasting of HLFs. Discretized heap leach models have been developed for several sites around the world. These models incorporate metallurgical data, tons and grade, PSD, ore stacking plans, pad geometry, kinetics, and hydrodynamics. The HLF is represented as a discretized matrix with vertical separation, representing lifts, to form spatially discrete cells. Activation of extraction and recovery is based on loading and leaching to allow for simulated growth, compaction, solution movement, and recovery over time. Each discrtized cell is quantified with ore properties and metals content including bulk density, initial moisture content, residual moisture content, metals content, and specific equations for detailing recovery. The model tracks solution movement and recovery of metals as a function of time based on unsaturated flow properties, kinetics dissolution and diffusion rates, and leaching dynamics. These models have been utilized by sites to evaluate the full mine-to-heap approach to assist operations with optimizing project performance. They assist with both short term and long term planning to bring ounces forward and enhance project NPV. They are important tools for trade-off evaluation and optimization of operational performance with respect to HLF recovery.

Brief Biography of the Author

Sean Guidi is a mechanical engineer with engineering and construction experience in dynamic systems modelling analyses related to heap leach facilities and other mining processes. He also has experience working as a process engineer, performing several models for existing operations to enhance production and analyze processing facilities. This has included optimization of project performance by evaluation various trade-off scenarios. Sean also has experience with development and maintenance of water balance models in GoldSim.

Forte Dynamics

Forte Dynamics is a mining consultancy firm providing an integrated mine-to-heap approach that looks at the entire heap leach mining process, including design, stacking, leaching operations, and the process plant. The result is project optimization on a much broader scale than has been possible in the past. The improved design, operations, and economics enabled by our approach make Forte Dynamics an essential partner for mining corporations worldwide. Find out more at www.fortedynamics.com.

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