High throughput online sequential extraction of natural rare earth elements and determination by mass spectrometry

As the beginning of rare earth industry, several days are normally required for characterization of rare earth elements (REEs) fractionation in ore samples. Herein, rapid fractionation analysis of 15 REEs and accompanied metal (Fe, Mn, etc.) in ore samples has been achieved within 1 h using ICP-MS with a homemade device for online sequential solvent extraction. As a result, five fractionations for REEs occurrences, i.e., water soluble, exchangeable, reducible, oxidizable and crystalline, have been identified, offering chemical insights which not only reveal the formation mechanism of REEs ores but also show great implications for guiding the exploitation and separation of REEs. In comparison with conventional methods, the present approach significantly shortened the analysis time (1 h vs. similar to 80 h) and reduced the sample consumption (1.0 mg vs. 5.0 g) with high recovery (>95%), providing a useful platform for the rapid quantitative fractionation analysis of REEs in complexed samples such as ore and fossils.

Automated summary

In this study, rapid fractionation analysis of 15 REEs and accompanying metals in ore samples was achieved within 1 h using ICP-MS with a homemade device for online sequential solvent extraction. The identified five fractionations for REEs occurrences offer chemical insights on the formation mechanism of REEs ores and guidance for their exploitation and separation. Compared to conventional methods, this approach significantly shortened the analysis time and reduced sample consumption, providing a useful platform for rapid quantitative fractionation analysis of REEs in complexed samples.