Application of Gettering Process on the Improvement of the Structural and Mineralogical Properties of Tunisian Phosphate Rock

摘要

The present study deals with the effects of gettering process on the structural and mineralogical composition of Tunisian phosphate rock. The treated samples were characterized to investigate the variation of physical structure and chemical composition as compared to the reference phosphate rock. The quantitative analysis of the impurities concentration before and after gettering treatment using energy-dispersive (EDX) reveals a significant reduction of impurity concentration (more than 75%) such as Al, Si, S, Na, and Mg. Scanning electron microscopy (SEM) shows that gettering process promoted structural alterations of phosphate rock sample due to fusion of impurities. The XRD patterns show that the chief mineral constituent of treated sample is only fluorapatite, while those in the reference ore were calcite, dolomite, quartz and carbonate-fluorapatite. FT-IR characterization show a disappearance of the bands related to calcite at 714 cm-1 as well as B carbonate situated at 1430 cm-1, 1458 cm-1 after gettering treatment. This result is in good correlation with Raman analysis.