Rare earth elements (REE) consist of lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd),
promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy),
holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu). Yttrium (Y) is also typically
grouped with the REE.
TREO are the total rare earth element oxides in the sample, with the REE metals expressed as rare earth element oxides, which is a common method for summarising the total grade.
This is TREO minus the amount of cerium oxide in the sample. CeO2 is relatively low in value.
Ppm is parts per million by mass, which is the standard unit for reporting REE grades. 10,000ppm =
Permanent magnets are used in electronic and computing equipment, batteries, electric vehicles, wind
turbines, mobile phones and military systems. Nd & Pr are used in high-power permanent magnets. Dy, Sm and Tb are used in high-temperature permanent magnets. Some reporters called them “Super Magnet” REE.
Ionic adsorption clay (IAC) rare earth elements
In contrast with hard-rock REE ores, ionic adsorption clay REE mineralisation forms when REE attach loosely to clays and can be recovered by low-cost leaching methods.
IAC REE deposits have been mined in southern China and Myanmar. ABx is one of the very few listed
companies to discover true IAC REE mineralisation in Australia.
Extraction rates from desorption tests
To assess the potential of extracting REEs from prospects, tests have been carried out by ANSTO, who have extensive experience in metallurgical testing of clayhosted rare earth deposits worldwide. These were conducted at “standard” desorption conditions of 0.5 M ammonium sulfate at pH 4 which are low-acid, low-cost processing conditions for ionic adsorption clay REE.
The ”extraction rate” is the proportion of REE contained in the sample that is extracted and reports to the leach solution. Very few other REE occurrences in Australia have achieved extraction rates that have been achieved on ABx’s REE mineralisation in the channels at the Deep Leads project area in northern Tasmania.