Production Pathways: Magnesite deposit at prospect ridge; north-western Tasmania

Critical metals play a crucial role in the advanced manufacturing industries and economies of nations worldwide because of their irreplaceable technological values in sustainable cleaner energy production. Both the demand for these metals to meet global energy security needs and the World Health Organization (WHO) net zero-carbon emission target present major supply chain challenges, particularly to the mining industry. According to Statista (2023), Australia contributed 2.6 million metric tonnes to the global magnesite annual production. This can be significantly increased if more investments in exploration, prospecting and characterization of new deposits are carried out to develop innovative and cost-effective production pathways for critical minerals/metals. In this regard there is growing interest in Australia in mining magnesite, a magnesium carbonate (MgCO₃) mineral out of which Mg can be extracted from.

Although there are conventional commercial routes for production of magnesite ores, including the Pidgeon and Electrolytic processes, some technological challenges are still being researched. For instance, the application of intensive heating of magnesite ores which is often costly and cell cathode passivation, due to high impurities content of the feed ore, during the electrolytic process the cell performance is severely affected. Hence, there is a pressing need to develop an effective yet cost friendly processing route for magnesite production.

The present research seeks to undertake comprehensive characterisation of the geology, alteration, mineralogy, Mg mineralisation and chemistry of the Prospect Ridge deposit in Tasmania through core logging and several field and lab-based analytical techniques (SEM-based automated mineralogy and XRF). Appropriate and cost-effective production route(s) will be assessed based on characterisation data to extract magnesite from associated gangue and other deleterious minerals via judicious use of beneficiation and extractive metallurgical techniques.