Economics of Bacterial Leaching

Abstract

Most bacterial leaching techniques to improve the recovery of metals from sulphide ores exploit the basic oxidation reactions performed by naturally occurring bacteria, the oxidation of sulphur to sulphate and the oxidation of ferrous iron to ferric iron. However, up to now bacterial leaching techniques have only been economical when a natural reactor system was used, e.g. dump leaching. The long leach residence times and low pulp densities made agitated leach tanks large and uneconomical.Joint development work has been undertaken by Davy McKee (Stockton) and University College Cardiff to reduce bacterial leach residence times and increase pulp densities such that bacterial leaching in reactors would be economical.