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Alex Opitz

PhD Project title
The Development of an Integrated Approach for the Prediction of Acid Rock Drainage from Waste Rock
(Duration: 2015 to 2019)

The formation of acid rock drainage (ARD) poses a serious environmental risk associated with the mining of sulphidic hard-rock ores and coal. Acidity generated from sulphide oxidation leads to an increase in heavy metals concentrations and salinity in the surrounding environment. ARD generation occurs naturally in the presence of water and oxygen and are catalysed by iron- and sulphur-oxidising microorganisms. Currently, the potential for ARD generation is characterised using a sequential process. Initially, chemical laboratory screening tests assess the overall potential for ARD generation. For samples which may produce ARD, kinetic tests are conducted to quantify the rate of acid generation using water and oxygen. The current methods, however, fail to account for the action of micro-organisms and to integrate the mineralogical composition of the waste with the ARD potential. My project aims to integrate the current ARD characterisation methods with detailed mineralogical analysis and test work developed to assess the role of micro-organisms on ARD generation. Furthermore, integration between laboratory-scale tests and those conducted in the field will be performed through the use of geochemical mass transport models.

Research Outputs
Opitz, A., Broadhurst, J.L., Becker, M., Harrison, S.T.L and Franzidis, J.-P. 2014. Assessing environmental risks associated with sulfidic mine waste: A gold case study. 21st General Meeting of the International Mineralogical Association (IMA 2014), 2-5 September, Johannesburg, South Africa. Also presented at the 32nd annual SAIMM Mineral Processing Conference, 7-8 August, Cape Town.

Courses & Training

  • Research Communication & Methodology
  • Acid Rock Drainage Prediction course