Modeling and Optimization of Carbon in Leach (CIL) Circuit for Gold Recovery

Abstract

Carbon in leach (CIL) is a critical gold processing step involving the simultaneous leaching of gold from ore and adsorption onto activated carbon particles. The interaction between these competing processes makes CIL circuit optimisation complex, as operating parameters affect both processes in different ways. This study develops a dynamic first-principles model of the entire CIL circuit and applies multi-objective optimisation to improve recovery and profitability while minimising reagent consumption.

A dynamic MATLAB-based model incorporating suitable kinetic models for both leaching and adsorption from literature was validated against available data. The validated model was used for sensitivity analysis to identify the key operating parameters governing circuit performance. Four decision variables were selected for optimisation: particle diameter, oxygen concentration, cyanide concentration, and ore volume fraction in tanks. Multi-objective optimisation using a genetic algorithm was performed to find the Pareto-optimal set of solutions that simultaneously maximise percent recovery and net profit while minimising cyanide consumption. The optimisation demonstrates that high recovery, high profit, and low cyanide concentrations can be achieved simultaneously through appropriate selection of operating conditions, providing a practical tool for improving the performance and sustainability of CIL gold processing circuits.

@article{wadnerkar2015modeling,
  title         = {Modeling and Optimization of Carbon in Leach (CIL) Circuit for Gold Recovery},
  author        = {Wadnerkar, Divyamaan and Tade, Moses O and Pareek, Vishnu K and Utikar,
                  Ranjeet P},
  year          = 2015,
  journal       = {Minerals Engineering},
  publisher     = {Pergamon},
  volume        = 83,
  pages         = {136--148},
  doi           = {10.1016/j.mineng.2015.09.001}
}