Figure 1 - Adapted laboratory flotation setup used in the flotation experiments, comprising a beaker-based flotation cell with a froth collection support, placed inside a water bath system to ensure temperature control during operation. 2.3 Chemical analysis As already mentioned, all products obtained from the flotation experiments, as well as the feed material, were analyzed for REE content by ICP-MS. Prior to analysis, the samples were subjected to microwave-assisted acid digestion using a mixed acid system consisting of hydrochloric acid (HCl), nitric acid (HNO₃), perchloric acid (HClO₄), and hydrofluoric acid (HF), following standard procedures for the complete dissolution of silicate- and carbonate-rich mineral matrices. Approximately 2 g of each solid sample were used for the digestion process. The resulting solutions were subsequently diluted to appropriate concentrations and analyzed by ICP-MS for quantitative determination of REEs. 3. RESULTS 3.1 Elemental chemical composition The elemental composition of the feed material and the flotation concentrates obtained in the first and second stages, as determined by XRF and ICP-MS analyses, is presented in Figure 2. The results indicate that calcium (Ca), iron (Fe), manganese (Mn), and barium (Ba) are the dominant elements in both the feed and the flotation concentrates, reflecting the carbonatite–ironrich nature of the Fen Deposit ore. Confirming the complex nature of the feedstock, composed mainly of sterile carbonates (anchorite, calcite, dolomite), quartz, barite, apatite and sulfides (pyrite) (Silva et al., 2023; Akyildiz et al., 2026). A broadly similar elemental composition between the feed material and the flotation concentrates was observed for most depressants, suggesting limited selectivity in the rejection of gangue minerals. This behavior indicates that the depressant dosages applied in the present study
RkJQdWJsaXNoZXIy MTM0Mzk2