Modeling of gold heap leaching for criteria of sustainability targets

A computational algorithm devised to simulate the temporal evolution of gold ore heap leaching process, in an attempt to better understand the phenomenology behind heap leaching and provide insights into the development of a sustainability indicator is described. The data used in the model include physical-chemical, geometrical and operational data. The shrinking-core model, describing the solid-fluid reaction under diffusion control, was used to calculate the variables. The simulations show that the number of layers has little effect on results indicating a stable and robust algorithm. The average residence time of the solution in the heap and the effective diffusivity of the cyanide solution through the ore particles have a significant influence on the temporal evolution of gold extraction. The results show that the model is able to predict the process performance reasonably, and might be used as a starter for sustainable development decision-making indicators.