Taruga Minerals confirms leachable rare earths at Morgans Creek target
ANSTO Minerals’ test work was able to extract up to 70% of the MREO and 60% of the HREO from Morgans Creek-clay hosted REE using a sulphuric acid leach.
Junior explorer Taruga Minerals (ASX: TAR) has reported initial extractions of up to 70% magnet rare earth elements (REE) during sulphuric acid leach trials on samples from the Morgans Creek target within the Mt Craig project in South Australia.
The work is being conducted by rare earth research and test work facility ANSTO Minerals and results so far have confirmed the presence of easily leachable REE within the deposit.
ANSTO has been able to demonstrate that extractions of up to 70% of magnet REE oxides (MREO) and 60% of heavy REE oxides (HREO) can be achieved with moderate sulphuric acid addition.
Variable extractions
Samples were intentionally selected to represent variability across the prospect, with extractions averaging 52% coming from the upper, middle and lower portions of the Yednalue Formation target unit.
Best results were 58% MREO extraction in the upper portion between 3 metres and 4m depth; 70% MREO extraction in the middle portion between 17m and 18m depth; and 59% MREO extraction in the lower portion of the unit between 35m and 36m depth.
Further optimisation work
Taruga said results provide confidence to proceed with further work to optimise the flowsheet in alignment with commercially-viable reagent and processing costs.
The work will include variations in leaching conditions such as reagent concentration and leach times, and beneficiation including processes such as sizing, ore-sorting and de-sliming.
Rare source
Morgans Creek is believed to represent a rare source of magnet and heavy rare earths, having a very high proportion of both (34% and 35% respectively).
Sources of heavy rare earths are becoming increasingly rare and commercially important due to depleting and unsustainable primary sources in China.
Over the last five years, China’s total REE production has increased by more than 200% however the nation has been unable to increase HREE production over the same period.
Experts suggest it indicates that sources of heavy REE are depleting and China is now processing more light REE dominant resources.