The rare earth elements (REEs) are the 15 lanthanides of the periodic table of elements, but often scandium and yttrium are included in the definition due to their similar chemical behaviour. The importance of this group of elements has grown in recent years due to use in a variety of industrial applications but particularly electronics, clean energy, and automobiles. Rare earth elements are found in two types of deposits: primary magmatic deposits and secondary concentration deposits, either by mechanical or chemical weathering.
Accurate analysis is vital in rare earth element (REE) exploration, particularly because many REEs are contained within minerals that are highly resistant to conventional digestion methods. Choosing the right analytical technique is therefore crucial to avoid underestimating REE concentrations and to ensure reliable data for effective decision-making. At ALS, we offer a range of advanced analytical solutions designed to achieve total recovery of REEs without compromising detection limits or sensitivity.
Our ME-MS71L™ method employs a unique ammonium bifluoride (ABF) decomposition technique. By utilising the high boiling point of ABF (239.5°C), this approach enables near complete extraction of rare earth elements, including those locked within refractory mineral phases. The method has been carefully optimised to enhance recovery and stability not only of REEs but also of critical high field strength elements (HFSE) and key pathfinder elements, providing comprehensive geochemical insights essential for exploration success.
Code | Analytes & Ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-MS71L™ 0.1g sample |
Al | 0.05-50% | Eu | 0.004-5,000 | Mo | 0.1-10,000 | Ta | 0.005-10,000 |
B | 10-10,000 | Fe | 0.05-50% | Na | 0.05-10% | Tb | 0.001-5,000 | |
Ba | 1-10,000 | Gd | 0.004-5,000 | Nb | 0.02-10,000 | Th | 0.004-10,000 | |
Be | 0.03-1,000 | Hf | 0.008-10,000 | Nd | 0.04-10,000 | Ti | 0.0002-20% | |
Ca | 0.01-50% | Ho | 0.002-5,000 | P | 0.002-20% | Tm | 0.001-5,000 | |
Ce | 0.1-10,000 | K | 0.05-25% | Pb | 0.5-10,000 | U | 0.01-10,000 | |
Co | 0.2-10,000 | La | 0.1-10,000 | Pr | 0.01-5,000 | V | 1-10,000 | |
Cs | 0.01-10,000 | Li | 1-10,000 | Rb | 0.05-10,000 | W | 0.2-10,000 | |
Cu | 2-10,000 | Lu | 0.001-5,000 | Sc | 0.04-10,000 | Y | 0.01-10,000 | |
Dy | 0.003-5,000 | Mg | 0.01-50% | Sm | 0.006-5,000 | Yb | 0.001-5,000 | |
Er | 0.002-5,000 | Mn | 0.005-50% | Sr | 0.4-10,000 | Zr | 0.5-10,000 |
Rare earth elements (REEs) can be efficiently extracted from ionic adsorption clays through the use of ammonium sulphate leaching. These clays are formed through the natural weathering of REE-rich minerals, during which REE ions become loosely adsorbed onto clay surfaces. The leaching process releases these adsorbed ions without the need to dissolve the host mineral structure—offering a selective method for recovering REEs from weathered deposits.
Code | Analytes & Ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-MS19™ 30g sample |
Al | 5-250000 | Fe | 5-500000 | Nb | 0.005-500 | Ta | 0.005-500 |
B | 10-10000 | Gd | 0.005-1000 | Nd | 0.05-10000 | Tb | 0.002-1000 | |
Ba | 0.5-10000 | Hf | 0.005-500 | Ni | 0.1-10000 | Th | 0.005-10000 | |
Be | 0.01-1000 | Ho | 0.002-1000 | P | 5-10000 | Ti | 5-100000 | |
Ca | 20-250000 | K | 20-100000 | Pb | 0.05-10000 | Tm | 0.002-1000 | |
Ce | 0.005-500 | La | 0.002-10000 | Pr | 0.004-1000 | U | 0.005-10000 | |
Co | 0.005-10000 | Li | 0.2-10000 | Rb | 0.05-10000 | V | 0.4-10000 | |
Cs | 0.005-500 | Lu | 0.002-1000 | Sc | 0.005-10000 | W | 0.01-10000 | |
Cu | 0.04-10000 | Mg | 1-250000 | Si | 10-10000 | Y | 0.005-500 | |
Dy | 0.005-1000 | Mn | 0.2-50000 | Sm | 0.004-1000 | Yb | 0.004-1000 | |
Er | 0.004-1000 | Mo | 0.01-10000 | Sn | 0.05-500 | Zr | 0.01-500 | |
Eu | 0.004-1000 | Na | 50-100000 | Sr | 0.03-10000 |
The main minerals mined for REEs are bastnasite, monazite, loparite, and laterite clays. Except for laterite clays, these minerals are highly resistant to acid digestion, requiring fusion or ABF digestion for complete decomposition and accurate analysis.
ALS method ME-MS81h is suitable for ore grade REEs and is provided from a lithium borate fusion with ICP-MS analysis. The upper limit for the trace elements by this method range from 5,000 to 50,000 ppm, however, over-range analysis by ME-OGREE can determine concentrations up to 30%. Alternatively, where the lower detection limit is of lesser concern, fusion-XRF method ME_XRF30, which also includes loss on ignition as part of the analysis, may be suitable.
Code | Analytes & Ranges (ppm) | |||||||
---|---|---|---|---|---|---|---|---|
ME-MS81h™ 0.1g sample |
Ce* | 3-50,000 | Ho | 0.05-5,000 | Rb | 1-50,000 | Tm | 0.05-5,000 |
Dy* | 0.3-5,000 | La* | 3-50,000 | Sm* | 0.2-5,000 | U | 0.3-5,000 | |
Er | 0.2-5,000 | Lu | 0.05-5,000 | Sn | 5-50,000 | W | 5-50,000 | |
Eu | 0.2-5,000 | Nb | 1-5,000 | Ta | 0.5-5,000 | Y | 3-50,000 | |
Gd* | 0.3-5,000 | Nd* | 0.5-50,000 | Tb* | 0.05-5,000 | Yb | 0.2-5,000 | |
Hf | 1-50,000 | Pr* | 0.2-5,000 | Th | 0.3-5,000 | Zr | 10-50,000 |
CODE | ANALYTES & RANGES (%) | |||||
---|---|---|---|---|---|---|
ME_XRF30 0.7g sample |
CeO2 | 0.01-50 | Ho2O3 | 0.01-10 | Sm2O3 | 0.01-10 |
Dy2O3 | 0.01-10 | La2O3 | 0.01-50 | Tb4O7 | 0.01-10 | |
Er2O3 | 0.01-10 | Lu2O3 | 0.01-10 | Tm2O3 | 0.01-10 | |
Eu2O3 | 0.01-10 | Nd2O3 | 0.01-10 | Y | 0.01-10 | |
Gd2O3 | 0.01-10 | Pr6O11 | 0.01-10 | Yb2O3 | 0.01-10 | |
OA-GRA05x ME-GRA05 |
Loss on Ignition | Furnace or Thermogravimetric Analyser (TGA). 1g sample. |
Where lower detection limits are required, two methods are suitable: ME-MS89L™ for trace values from a sodium peroxide fusion, or ME-MS81 from lithium borate.
MORE INFORMATIONMethods for determining rock forming elements may be added to both the ME-MS81™ and ME-MS89L™ REE exploration methods.
MORE INFORMATION