Caracterização tecnológica do rejeito de cromita

Abstract

Brazil has a small share in world reserves and supply of chromite, in the order of 0.13% and 2.47%, respectively. In 2015, 107,494 t of chromite were imported, of which 93% came from primary goods. The data show that chromite production is insufficient to meet its current needs. The use of reject requires the technological characterization, aiming at a later study for the definition of a beneficiation plant with a view to its utilization. The use of tailings requires the technological characterization, aiming at a later study for the definition of a beneficiation plant with a view to its utilization. With this objective was collected a sample of 150 kg of waste from a plant in Northeast Brazil. The collected material was submitted to drying, followed by homogenization and blocking by means of prismatic cells. Aliquots were generated to characterize particle size distribution, chemical composition (FRX), mineralogical composition (XRD) and liberation degree (Gaudin method). The results showed that the tailings have an average of 8.41% Cr2O3, reaching a content of 29.0% Cr2O3 for sizes of less than 53μm. The studied tailing is composed mainly of the minerals chromite, serpentine and talc. It has been found that 48% of the tailings particles are less than 300μm. Finally, it was observed that 80% of the chromite is liberated from 150μm.