Minerals replacement reactions: understanding mineral formation under hydrothermal conditions. Many geological processes involve the transformation of one mineral into another. By understanding molecular-level reaction mechanisms, we can predict how fast reactions progress, and what the final product will look like. This project focuses on a reaction mechanism called 'coupled dissolution-reprecipitation', in which the parent mineral is dissolved into a thin layer of fluid at the reaction front, ....Minerals replacement reactions: understanding mineral formation under hydrothermal conditions. Many geological processes involve the transformation of one mineral into another. By understanding molecular-level reaction mechanisms, we can predict how fast reactions progress, and what the final product will look like. This project focuses on a reaction mechanism called 'coupled dissolution-reprecipitation', in which the parent mineral is dissolved into a thin layer of fluid at the reaction front, and the daughter mineral subsequently precipitates. This concept will be applied to sulfide minerals for the first time. The results have many applications for the Australian mining industry, in particular in improving the efficiency of the processing of Ni- and Au-ores.Read moreRead less
Resistivity of typical rocks at crustal pressure and temperature conditions from combined laboratory and magnetotelluric measurements. Magnetotelluric surveys are playing an increasing role in Australian geoscience, including academic research, data collected by geological surveys (including a role in Geoscience Australia's $58.9 million Onshore Energy and Security Program), mineral exploration and geothermal exploration. This project will enable the results of these surveys to be interpreted mo ....Resistivity of typical rocks at crustal pressure and temperature conditions from combined laboratory and magnetotelluric measurements. Magnetotelluric surveys are playing an increasing role in Australian geoscience, including academic research, data collected by geological surveys (including a role in Geoscience Australia's $58.9 million Onshore Energy and Security Program), mineral exploration and geothermal exploration. This project will enable the results of these surveys to be interpreted more accurately and meaningfully by constraining the expected resistivities of crustal rocks at various pressures and temperatures. This research is vital if the investment currently being put into MT surveys is to be capitalized upon. Read moreRead less
Experimental studies on hydrothermal reaction processes at the molecular level: the role of mineral replacement reactions in ore formation. Most of the World's supply of metals such as copper (Cu), gold (Au), molybdenum (Mo), lead (Pb), zinc (Zn) or uranium (U) comes from hydrothermal ore deposits. The metals were deposited deep below the Earth's surface when hot fluids, carrying minute quantities of the metals, reacted with suitable rocks to form ore minerals. By understanding molecular-level ....Experimental studies on hydrothermal reaction processes at the molecular level: the role of mineral replacement reactions in ore formation. Most of the World's supply of metals such as copper (Cu), gold (Au), molybdenum (Mo), lead (Pb), zinc (Zn) or uranium (U) comes from hydrothermal ore deposits. The metals were deposited deep below the Earth's surface when hot fluids, carrying minute quantities of the metals, reacted with suitable rocks to form ore minerals. By understanding molecular-level reaction mechanisms at high pressure and temperature, we can predict the nature of the ore minerals formed for a given set of physical and chemical conditions. This multidisciplinary research project is devoted to understanding these chemical and physical processes and how this knowledge can be applied to improve mineral exploration, mining, and ore processing.Read moreRead less
Transport of metals in vapours and brines: new insights into the formation of the Earth's mineral deposits. Traditional models for the formation of hydrothermal ore deposits assume that aqueous fluids transported the metals. This view is challenged by new observations showing that gold and copper are preferentially enriched in vapours coexisting with salty aqueous fluids in some deposits. This project uses state-of-the-art techniques and develops new instruments to measure experimentally the par ....Transport of metals in vapours and brines: new insights into the formation of the Earth's mineral deposits. Traditional models for the formation of hydrothermal ore deposits assume that aqueous fluids transported the metals. This view is challenged by new observations showing that gold and copper are preferentially enriched in vapours coexisting with salty aqueous fluids in some deposits. This project uses state-of-the-art techniques and develops new instruments to measure experimentally the partitioning of metals between solid, fluid and vapour at temperatures typical for natural ore deposits (350-550C, pressures varying for vapour saturated to 1 kb). By improving our understanding of metal transport within the Earth's crust, these data will lead to improved models and technologies for exploring and processing base and precious metals.Read moreRead less
Nickel iron sulphide mineralogy: the link between mineral transformations and microstructure and magnetic properties. This project is about measuring the rate at which minerals transform or react and how metal diffusion controls these reactions. Metal diffusion in sulphides is much more rapid that in silicates and is still very significant at low temperatures (< 300 C). In this project, we are trying to measure the rate at which the principal ore of nickel, pentlandite, transforms to violarite ....Nickel iron sulphide mineralogy: the link between mineral transformations and microstructure and magnetic properties. This project is about measuring the rate at which minerals transform or react and how metal diffusion controls these reactions. Metal diffusion in sulphides is much more rapid that in silicates and is still very significant at low temperatures (< 300 C). In this project, we are trying to measure the rate at which the principal ore of nickel, pentlandite, transforms to violarite, another important nickel rich sulphide that forms from it in the upper parts of ore bodies. The arrangement of the metal atoms in these minerals is sensitive to temperature, so it may be used as a geothermometer.Read moreRead less