Potencial geológico e mineral de elementos terras raras na Paraíba: caracterização física e química

Abstract

Monazite is a phosphate light rare earth mineral [(REEL)PO4] which occurs in association with titanium ore. Rare earth elements (REE) form the group of lanthanide compounds, elements that play a huge role in global economic growth and the modern technology market. This technological resource, the rare earths, is widely distributed throughout the world, but China has a monopoly on it. The global demand for REE has led China - the "leading producer of REE" - to limit its export quotas, thus reducing the supply of REE. Due to the depleting availability of RE, other countries have started to look for alternative and additional sources of REE. The Brazil has an important role to play, since it has a large scale of exploitable deposits. However, little of these inputs is produced and consumed due to a lack of appropriate technology. Given this scenario, several studies have been conducted to increase the exploration and production of these in the country. Three main minerals are considered for REE element extraction to be feasible: the monazite mineral, which is the objective of this study, bastnasite and xenotime. The work aims to collect data information on the chemical composition, microstructure e the crystal phases of the ilmenite ore concentrate tailings. In this work the chemical and mineralogical characterization was performed. Therefore, a characterization study was performed using XRD techniques, X Ray fluorescence and scanning electron microscopy (SEM) equipped with energy-sidpersive X Rray spectroscopy (EDS), this last analysis has seen noted the morphological details on the surface of the sample, and the other hand the composition and the identify mineral phases were studied by FRx and DRx. The sample was classified into four size classes: range of size 0.595mm, size 0.420mm, size 0.297mm and size 0.210mm. The XRF analysis confirmed the presence of Si, Al, Fe, Ti oxides and rare earth oxides typescripts: REO’s (Ce, La and Nd). The XRD results revealed the presence of quartz, most of all, which as expected, then, is characterized as the gangue mineral. Moreover, the XDR analysis identified traces of monazite phases ((Ce, La, Nd, Th (PO4)). This is due to the fact in which stage of mineral processing the raw material was collected and analyzed. Traces of Si, Al, Fe, Ti, Ca, K were also confirmed by SEM elemental mapping. To reduce the increase in mining beneficiation costs, a preliminary mineralogical analysis is needed to mine the RTS efficiently.