OREAS 462

OREAS 462 is an ore grade, rare earth element (TREO = 1.54%)
matrix-matched certified reference material (MMCRM) prepared and certified by
Ore Research & Exploration. The materials constituting OREAS 462 were
sourced from Lynas Corporation’s Mount Weld Project (the ‘Central Lanthanide
Deposit’) which is located 35 kilometres south of Laverton in Western Australia.
The Mount Weld source materials (waste, low and medium grade REE ores) were
found to be highly hygroscopic to the extent that significant analytical errors
would likely result during analysis unless strict moisture handling procedures
were adhered. To avoid this complication, the hygroscopic property was destroyed
by roasting the materials at 900°C for 2 hours. Following re-equilibration of
the materials to laboratory atmosphere the hygroscopic moisture content was
deemed acceptable (~0.5% H2O-).
OREAS 462 is one of six MMCRMs ranging TREO 0.53 – 9.88% and contains 111
certified values (and 50 indicative values) including REE’s, majors and traces
by fusion XRF, fusion ICP and 4-acid digestion.
A summary of the mineralogy and supergene enrichment processes that operated
in the host lateritic rocks is given in the Certificates of Analysis. Two
‘Datapack’ files are provided. The ‘Elemental’ version contains all Certified
Values in their elemental form while the other Datapack shows some of the
Certified Values in oxide format. This includes the fusion XRF group and the
majors and REE’s (and a few other associated metals) in the fusion ICP
group.