Primary Evaluation of Rare Earth Elements Status of Esfordi Phosphate Mine Using Outlook Coefficient Method

The studied area in this research is the Esfordi phosphate mine in the Bafq metallogenic state, which apatite, magnetite and hematite are its main mineralization. As one of the high phosphorus iron – apatite mine in the region, this mine contains significant mineralization of rare earth elements with a maximum and average grade of 1.7% and 0.5% (as monazite, zircon and allanite minerals in apatite), and has LREE enrichment and Eu negative anomaly.  In order to primary assessment of REEs concentration status in study area, the outlook coefficient of REEs (Koutl), which is based on the classification of REEs by the level of industry demand, was used. This coefficient is the ratio of the amount of critical REEs (Dy, Tb, Nd, Y, Er and Eu) to the amount of surplus REEs (Ce, Ho, Tm, Yb and Lu), which can be used to investigate mineralization of different types in newly discovered deposits and active mines. The results indicate the highest outlook coefficient (Koutl=0.67) for microgranite to rhyolite with amphibole unit, and also promising average outlook coefficient of 0.53. The Esfordi mine despite the lower grade, it is closer to the ideal composition compared to China's Bayan Obo mine (Koutl=0.2). Thus, can portend a bright future for REEs in this mine, if focus on exploration of these elements and further geochemical and mineralogical investigations are carried out.