Coupling PhreeqcRM with GoldSim: New perspectives for the Mining Industry

Posted by Jason Lillywhite

Benoît Paris (bparis@intera.com) and Ken Esposito (KEsposito@intera.com) from Intera Geoscience and Engineering Solutions recently developed a model that couples PhreeqcRM with GoldSim using an external dynamic link library (DLL). Their model is highly flexible and efficient as it enables the user to run numerous types of simulations without the need to change the DLL, thus saving potentially significant model preparation time. This tool offers mine operators the possibility to evaluate potential mine impacts and make operational decisions in real time using scientifically-defensible mechanistic models in a probabilistic framework.

This coupling has been successfully benchmarked against examples from the PHREEQC manual and tested on a complex acid rock drainage conceptual case. While being completely dynamic and seamless, this implementation runs nearly as fast as native PHREEQC simulations allowing Monte Carlo calculations to fully propagate uncertainty in transport models.

The PhreeqcRM DLL, and its implementation within GoldSim, has been benchmarked against the Phreeqc code (Version 3.5.0) using several examples (#7, 11 & 14) from the PhreeqC manual to check the validity of their approach for simulating various coupled reactive processes. For the comparison, a 15-cell model (plus one injection cell and one extraction cell) is built using the GoldSim software (Figure below).

Network of GoldSim cells for simulating Example 11 from the Phreeqc manual

The integrated simulation tool presented in this paper allows the site-specific flow system data to be combined with a geochemical model to depict geochemical reactions that will likely occur in dynamic, real-world water balance and mixing scenarios. Our integrated model is ideal for solving mixing, chemical equilibrium and aqueous speciation problems in complex systems at operating or planned facilities. This seamless approach largely simplifies the model setup while minimizing calculation times compared to previous DLL approaches. This tool can be used to evaluate mine or nuclear waste disposal concepts and to make real-time operational decisions using scientifically defensible, mechanistic models through a probabilistic framework.

To read more about this model, please read the full paper here.