Flotation response of parisite, monazite, bastnäsite and synchysite from a carbonatite deposit

The European Green Deal targets a carbon-neutral, resource-efficient economy by 2050. Rare earth elements (REE) are essential to this transition, especially for green energy technologies. However, rising demand and supply concerns have prompted research into REE mining and processing. This study focuses on flotation behavior of rare earth minerals (REM), particularly parisite, monazite and bastnäsite, synchysite from a Norwegian carbonatite deposit. REM (parisite, bastnäsite, monazite, synchysite) were tracked throughout the beneficiation process using ICP-MS and SEM-based automated mineralogy. Results showed 72 % recovery of total rare earth oxides (REO) with a 48 wt% REO grade in the final concentrate. The second cleaner step yielded a concentrate with 39 wt% parisite (72 % recovery), 14 wt% bastnäsite (75 % recovery), 8 wt% monazite (70 % recovery), and 4 wt% synchysite (69 % recovery). In this study, mineral association patterns of major REM subtypes (parisite-Ce, parisite-Ce-La, monazite-Ce, bastnäsite-Ce-La, and synchysite-Ce) were analyzed across all beneficiation products and the feed. The mineral association analysis revealed that parisite-Ce and bastnäsite-Ce-La had similar trends, while monazite-Ce was associated with apatite and barite, reflecting its geochemical origin. Synchysite-Ce had the highest intergrowth with other REM and the lowest liberation. Nevertheless, all target minerals exhibited a sufficient surface exposure to be successfully recovered in the final concentrate, meeting the requirements for a marketable REM concentrate. The study offers critical mineralogical insights into REM flotation, particularly the underexplored parisite, supporting future beneficiation strategies for carbonatite-hosted REE deposits. • SEM based automated mineralogy was used to characterize the feed and products. • The valuable minerals identified in the ore include parisite, monazite, bastnäsite and synchysite. • The degree of liberation and mineral associations were investigated. • A recovery of 72 % of the total rare earth oxides was achieved in the product, with a grade of 48 wt%.