Computer codes to simulate and model the performance of leach pads abound—any code that calculates a factor of safety against instability will work on a heap leach pad problem, and the same is true for most aspects of heap leach pad performance. For example, SOILVISION SYSTEMS sells SVFlux to analyze unsaturated flow in a pad—when coupled with ChemFlux you can study the effect of the input chemistry on the output chemistry.

Jensen and Taylor compare some codes for specifically evaluating the chemistry of heap leach pads. Here are two:

METSIM has a heap leach model that is part of their comprehensive suite of computer codes to address complex chemical, metallurgical, and environmental processes. The heap leach module performs mass balances around the heap leach process including chemical reactions, precipitation and evaporation, solids and water inventories, heap drainage and control logic. The model is non-steady state and generates time dependent plots. The model allows input of several ore types with separate recovery curves for each ore type. Detailed data on the day to day operation of the heap are provided. Comparisons of control strategies, the effects of changing key parameters and the effect of seasonal variations can be evaluated.

Leach, Inc. has a software package to scale up and simulate a heap leaching operation based on engineering and kinetic fundamentals of the leaching process. Using results from a column leach test or a commercial heap operation LEACH will allow you to quickly predict heap performance under different operating conditions such as particle size distributions, heap heights, solution flow rates and solution chemistry. The projections are based on fundamental principles not rules-of-thumb. The program is applicable to all copper and gold heap leaching operations as lab tests results or field data from each operation is used to initialize the program.