Leachate of Brukunga Mine site - A reactive modelling study

Author: Joshua Edwards

Edwards, Joshua, 2019 Leachate of Brukunga Mine site - A reactive modelling study, Flinders University, College of Science and Engineering

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Abstract

Reactive modelling of bench scale column leachate tests conducted on the Brukunga Mine, utilising tailings and waste rock material, to determine appropriate amounts of calcium carbonate (CaCO3) blended with this material and permanently saturated to neutralise resultant leachate produced through limiting reduction oxidation processes (REDOX). Results of the column tests were used to create the model, with specific concentrations of key constituents to be achieved during the modelling setup and calibration. Dissolution and REDOX of Pyrite was the primary constituent responsible for the resultant leachate with secondary dissolution and REDOX of Pyrrhotite resulting in latent increases in leachate throughout the column tests, also displayed in the model. Elevated concentrations in Sulfate and Iron were observed throughout the model, with a limited decrease in these constituents compared to results obtained form the bench scale trials. Addition of minerals Goethite and Haematite improved the overall accuracy of the model, along with the consideration that CaCO3 may not be the only mineral neutralising the leachate, additional minerals Siderite and Gibbsite may be aiding the neutralising process throughout the evolution of the leachate.

Keywords: Leachate, Brukunga Mine, Modelling, Reactive, Hydrogeology

Subject: Earth Sciences thesis

Thesis type: Masters
Completed: 2019
School: College of Science and Engineering
Supervisor: Ilka Wallis