Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

The ore of the Vergenoeg fluorite mine, South Africa, contains rare earth elements in concentrations that may be of commercial interest. To assess the distribution of the rare earth minerals in the industrial flotation process currently used to produce fluorite concentrates, one mining block, that was carefully chemically, mineralogically and petrographically characterised, was fed to the flotation plant and subsequently the plant was systematically sampled. Mineral liberation analysis was conducted on the feed and the flotation products. Monazite and xenotime are the two main rare earth minerals. They are microcrystalline and occur mostly in association with each other and with iron oxide minerals in the ground flotation feed. A Particle Tracking technique was used to process the mineral liberation analysis and to assess the flotation behaviour of monazite and xenotime. Based on the study, different flotation behaviour was proposed for liberated and locked monazite and xenotime. The highest grade of monazite and xenotime was found in the tailing sample from the second cleaner unit of the flotation plant. Monazite and xenotime show high degree of liberation in this product. The tailings, especially of the second cleaner unit, were recommended for further beneficiation of rare earth elements.