Estudo químico de minerais do grupo xenotímio nos pegmatitos ao redor da mina da Volta Grande, visando elementos terras raras

The work aims to study two concentrates of heavy minerals derived from pegmatites located around the Volta Grande Mine for the identification of its main mineral constituents, characterization of the rare earth elements carriers, with focus on xenotime. Sampling involved about 20 kg of material of saprolite from the pegmatites, 92 2016 - XXIV – Jornada de Iniciacao Cientifica-CETEM washed, deslimed and panned in the field to concentrate heavy minerals. The final concentrates were sonicated and processed in bromoform (S.G, = 2.89), methylene iodide (S.G,= 3.32), ferrite hand magnet and Frantz isodynamic magnetic separator (0, 3, 0.5, 0.6, 0.8, 1.0, 1.5 and 2.0A) aimed at separation of para- and diamagnetic minerals by magnetic susceptibility. All products were studied by stereomicroscope, Raman spectroscopy and SEM-EDS. Preliminarily mineralogy of the Ribeirao Mosquitos pegmatite: ilmenite, columbite-tantalite, garnet, xenotime, monazite, epidote, cassiterite, gahnite, pyrite, zircon, microlite, phenakite, spodumene, iron oxide and tourmaline; and pegmatite Tais 2: ilmenite, garnet, iron oxide, epidote, columbitetantalite, monazite, gahnite, zircon, rutile, diopside and apatite. The REE bearers are monazite, xenotime and apatite. Xenotime-(Y) also carries relatively high levels of medium (Sm - 1.3% and Gd - 4.8%) and heavy REE (Dy - 4.9%) .