of the effects of grain size to mine water quality and Acid Rock
Drainage (ARD) production in Kinetic Testing

Embile Jr is representing MinSouth, from The University of

quality of mine drainage from sulfide containing waste dumps is
controlled by several factors and surface area (grain size) exposed
to weathering conditions is important. However, the textural
variation may control the main driving mechanisms for an acid
generating or neutralizing reactions. Depending on their rates and
intrinsic properties, leachate chemistry for a certain grain size
can be characterized through different types of tests and analysis.
Kinetic test using humidity columns is performed on five different
grain size ranges of waste rocks. Water leachate quality is
analysed on a weekly basis for their pH, alkalinity, conductivity,
anions, cations and dissolved metal concentrations. Results showed
that finer grains produced near neutral to neutral pH and higher
sulfate production rates unlike for coarser grains. This indicates
that the rate of sulphide oxidation and neutralization may be only
partly controlled by grain size as well as a number of interrelated