Heap Leach Crush Size Optimization - VAT Leach Testing

Nick Gow, PhD, QP - ngow@forteanalytical.com, Forte Analytical, CO, USA

Significant efforts have been made in recent heap leach models to improve the accuracy and consistency of gold production forecasts. It starts with breaking the heap leach facility into manageable cells which can be customized based on the client’s level of resolution. The discretized model tracks numerous metallurgically relevant inputs such as ore type, tons and grade, particle size distribution, pad stacking and geometry, leach kinetics, and solution hydrodynamics. Frequently, these criteria are not well defined, or operations are unable to project changes to production based on changing site conditions. It is critical that the metallurgical testing programs are defined well enough upfront to provide a broader array of information such that an operation can be able to adjust based on their actual mining and process condition.

Forte Analytical recommends VAT leach testing as part of the need to understand the leach recovery rates of an orebody both by crush size and alteration type. VAT leach can be employed early in the design phase of a new or upcoming ore body in order to optimize a crush size and NPV for a heap leach. Gold recovery and leach kinetics can then be projected by alteration type to determine an overall optimal crush size balanced by operating expenditures and anticipated mine plan. Once developed, the recovery parameters become an integral part of a dynamic model used to project the production of gold recovery through time at various sizes, leach cycles, and stacking conditions to provide an optimized operating scenario.

Forte Analytical is here to assist with all stages of your heap leach needs.

Forte Analytical is an independent metallurgical research and testing laboratory dedicated to open pit mine and heap leach facility advancement, providing a modern approach to analytical, geotechnical, and metallurgical testing services. Forte Analytical is a division of Forte Dynamics, an engineering and consulting firm known for surface mine and heap leach systems engineering. The Forte group, including Forte Dynamics, Forte Analytical, and Opencontour, provides an expansive list of services to support mining companies in maximizing profits and efficiencies.