European Resources Ltd. has announced the results of downstream metallurgical test work conducted by the Australian Nuclear Science and Technology Organisation (ANSTO) on historical stockpile material at the Korsnäs project in Finland.
The testing extracted 88 per cent of praseodymium and 83 per cent of neodymium from an untreated lanthanide concentrate using a conventional direct acid-bake and water-leach process.
Total magnet rare earth extraction reached 83 per cent, while total rare earths plus yttrium (TREY) registered an 86 per cent extraction rate.
The successful trial significantly de-risks the downstream processing flowsheet for the 100 per cent owned European Union project by proving that its main value-bearing monazite component responds efficiently to standard treatment.
European Resources Managing Director Jason Beckton said: “ANSTO’s latest results are an important de-risking step for Korsnäs.
“The direct bake test has shown that the key magnet rare earths can be extracted at high levels from the historical concentrate using the acid-bake route.
“This is no longer just a question of what minerals are in the concentrate. ANSTO has now demonstrated that the main value-bearing monazite component responds well to treatment.”
While light and magnet rare earths showed strong extraction, heavy rare earth yields were lower, with terbium at 49 per cent and dysprosium at 43 per cent.
Consulting metallurgist Mark Steemson explained this was expected, as a portion of the heavy rare earths are hosted in apatite minerals that become tied up during direct baking.
To resolve this, the next phase of development will focus on optimising a complementary flowsheet. This will introduce a hydrochloric acid pre-leach stage to handle the apatite and calcite fractions before applying the acid bake to target the monazite.
The breakthrough comes alongside broader exploration success at Korsnäs, where recent passive seismic surveys have detected new anomalies outside the current mineral resource estimate.
