ABSTRACT
The cold temperature conditions of northern climatic regions could be suitably utilized in the prevention and control of acidic drainage resulting from weathering and oxidation of sulphide bearing mining waste.
In laboratory column leaching experiments using unsaturated low sulphide gold tailings, it is demonstrated that the onset of acidic drainage is delayed and its severity decreased with the lowering of temperatures from 25°C to 2°C.
The impact of cold temperatures conditions on acid generation is modelled for various moisture regimes from unsaturated to water submersion. It is concluded that despite significantly reduced relative reaction rate constants at low temperatures, the flux of oxygen into the waste and hence the rate of acid generation is estimated to decrease only by a factor of 2.5 from 25°C to 0°C under unsaturated conditions. The effectiveness of saturating the tailings to limit oxygen influx is calculated to decrease as the temperature is lowered.
