The effect of rehabilitation on the rate of oxidation of pyrite in a mine waste rock dump

Temperature profiles within a mine waste rock dump undergoing pyritic oxidation have been used to estimate the rate of oxidation and the sites where oxidation was occurring. The waste rock dump is located at the abandoned Rum Jungle mine site in Northern Australia and was a major source of pollution to the local river system. The dump was rehabilitated in 1983-84 by reshaping to reduce erosion and covering with clay and soil to reduce infiltration of water.Heat source distributions were derived from temperature profiles measured in the dump. The oxidation of pyritic material is the main cause of heat in the dump, hence the rate and location of oxidation can be obtained from the distribution of heat sources. A comparison of the heat source distributions before and after rehabilitation showed that rehabilitation greatly reduced or stopped the oxidation of pyrite in the dump.