A/Prof Anita Parbhakar-Fox is a Principal Research Fellow and leads the Mine Waste Transformation through Characterisation (MIWATCH) group at the University of Queensland. Anita's research is focussed on improving mine planning and waste management practices by establishing new toolkits for predicting acid mine drainage. Additionally, she is leading government funded projects characterising a range of mine waste materials to evaluate their economic potential with a focus on critical metal recovery.
@parbhakarfox is me on twitter.
The global response to climate change, initiated by the Paris Agreement, has been to encourage countries to transition to low-carbon economies. New technologies such as electric vehicles, low-emission power sources and products for the medical and defence sectors are required to support this. The manufacture of these products requires resources of ‘critical metals’ including cobalt, tungsten, rare earth elements, indium, gallium and germanium. Traditionally, these metals were considered unwanted by-products of base metal and precious metal mining operations, and consequently are concentrated in mine waste.
Mine waste reprocessing is a business proposition that is increasingly being adopted in many countries, including several in Australia e.g., the Hellyer, Century, Mt Carbine, Mt Morgan and Tick Hill Mines. However, these materials are mineralogically heterogeneous thus, a ‘one approach-fits all’ will not optimise value-recovery or indeed, guarantee that the waste is environmentally de-risked. Fundamentally materials must be thoroughly characterised adopting similar practices as undertaken in geometallurgical studies.
In Australia, a national-scale secondary prospectivity program has recently been established with significant progress already made in Queensland. Here, at least 40 significant metalliferous mining operations producing mine waste streams containing unknown quantities of critical metals. Additionally, there are 120 state-managed abandoned mines. Many of these sites contain reactive sulphide-rich mine waste with associated acid and metalliferous drainage risks. The ongoing management of these sites is costly, but their potential critical metal content – as yet uncharacterised – presents a unique opportunity to rehabilitate these sites through reprocessing waste. The critical metal fertility of 22 sites has to date been examined and reprocessing potential of reactive mine waste assessed. Hosting of Co in sulphides and Mn- and Fe-oxides was commonly observed in tailings, waste rock and spent heap leach materials collected in NW Queensland with REEs in tailings hosted by allanite, stillwellite and Fe-oxides.