Prof. Joel Brugger - Honours Projects
Investigating the effect of water on the ‘solid-state’ synthesis of chalcopyrite
Chalcopyrite (copper iron sulphide) is an important resource of copper, and is mined at a variety of locations around the world. Despite this, the mechanisms of formation of chalcopyrite are not fully understood. Chalcopyrite should be producible from both hydrothermal and solid-state syntheses; however recent studies in this research group have produced some surprising results. ‘Solid state’ syntheses of chalcopyrite have only succeeded after adding microlitre quantities of water to a solid-state synthesis – which of course implies this is no longer truly a solid-state synthesis! It has been postulated that the presence of water acts as a medium for sulfide dissolution allowing proper mixing, the lack thereof causes various intermediate Cu-Fe-S compounds to form. Determining the role minute quantities of water play in this system has potentially wide-reaching implications for the behaviour of water in deep crustal environments where water is scarce. This project will be primarily laboratory based, supported by computer modelling and a variety of characterisation techniques.
Strong interest in geochemistry and chemistry is required. The project is aoso suitable for students with an engineering or chemistry background.
Co-precipitation/adsorption of native Pb onto natural sulfide minerals
Lead is a deleterious element that is found in sufficient concentrations in copper bearing ore bodies and is often upgraded during the processing of these ores. Additionally, sufficient concentrations of Pb are also found in the tailings that undergo Acid mine drainage, resulting in severe contamination of native water streams and ground water systems. Previous work has been conducted to investigate the role of Pb adsorption onto typical sulfide minerals characteristic of mine tailings including chalcopyrite, pyrite and hematite as a function of pH representative of environmental conditions. The present work will aim to further expand our current understanding of Pb speciation under variable metal-cation concentrations to mimic “real-world” conditions in order to study the deportment of Pb from ore processing to ore-tails. This will be conducted using a novel flow through column setup, where variable solutions will be held in contact with target minerals to explore the micro-scale interactions that occur leading to co-precipitation and adsorption of Pb supported by various characterisation and modelling techniques.
Mineral dissolution, transport and deposition in hydrothermal fluids
Collaborating organisation(s): CSIRO Mineral Resources Flagship (Weihua Liu).
Metals are transported within the deep Earth at high pressure and temperature by fluids possessing a complex chemical makeup; knowledge of the identity, stoichiometry and thermodynamic properties of metals in those fluids is thus essential for modelling the dissolution, transportation and deposition of minerals. This project will investigate metal behaviour in wide range of temperature, pressure and chemistry conditions and the role of environment changes in mineral depositions. The aim of this project is to provide not only macro scale understanding of mineral replacement reactions and metal solubility in hot fluids, but also micro scale insights into metal complexation and molecular structures via state-of-the art synchrotron based X-ray spectroscopy (mAESTRO autoclave system recently commissioned at the Australian Synchrotron) and first principle molecular dynamics. Strong background of geochemistry, chemistry and physics is required; basic knowledge of thermodynamics would be a bonus.