Finite volume discretisation for solving acid mine drainage problems

Authors: R. Singh, F. D. Ardejani

Many environmental problems associated with the mining industry involve the understanding and analysis of fluid or gas flow.

Typical examples include groundwater flow, transport of contaminants, and teat transfer.

The long-term pyrite oxidation and transportation of the oxidation products are noted to be the most important problems that can be modeled in order to predict the transport of the contaminants through groundwater flow systems, to interpret the geochemistry and achieve a better understanding of the processes involved.

Computational Fluid Dynamics (CFD) makes it possible to model the processes in which fluid flow, mass transport, heat transfer and chemical processes such as pyrite oxidation are involved.

This paper attempts to describe mathematically the numerical finite volume discretisation of the groundwater flow, pyrite oxidation, atmospheric oxygen transport and the solute transport governing equations.

These eąuations have been numerically solved using a CFD package called PHOENICS.

For all non-standard calculations for this package, the necessary modifications have been carried out by applying FORTRAN 99 coding in a user accessible subroutine.