For the analysis of refractory ores the pretreatment method must be selected carefully
REE- and other refractory ores
Many minerals hosting the rare earth elements (REE) are refractory and the acid digestion methods used in the analysis of these elements are not always effective enough to liberate the REE’s from their minerals. The peroxide fusion method (method 720) is the most reliable method for for total analysis of both light and heavy REE’s.
Labtium method 720M using ICP-MS will give all the REE’s and additionally some other elements (U, Th, Nb, Ta) included in typical ore deposits. Combined with ICP-OES analysis (720P) major, minor and tarce elements will be included in the extended package (720PM).
Also total digestion methods (methods 306PM and 307M) can be used with possibilty that some REE-bearing minerals are not totally digested,
XRF -analysis (175X) can be used to cover a large elements suite , including some of REEs.
Li-ores, pegmatites and phosphate -ores
Labtium recommends either peroxide fusion based analytical packages (720P, 720M or 720PM) or XRF-analysis from pressed pellets (175X).
Fluorine can be analysed on low levels (<2%) with NaOH-fusion and ion selective electrode (method 725I). High grade ores are analysed with XRF from presseded powders (175X).