Mineralogical and physical beneficiation studies for iron extraction from Bardaskan titanomagnetite placer deposit

In this work, a bench-scale process was developed using mineral-processing methods to recover iron from a placer deposit located in Bardaskan, Khorasan-e-Razavi, Iran. The mineralogical studies were performed by X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Electron Probe Micro-Analyzer (EPMA), and an optical microscope. These studies indicated that titanomagnetite, magnetite, and hematite were presented in the sample as valuable minerals. In contrast, the gangue minerals were silicates such as pyroxene, plagioclase, quartz, feldspar, calcite, and some secondary minerals. The optimum liberation degree of the iron-containing minerals was obtained to be 75 µm with average Fe and TiO2 contents of 5% and 1%, respectively. The analysis showed that magnetite was the main iron mineral, and most of the hematite was formed due to martitization. Also minor ilmenite contents were found in hematite and magnetite in a blade form. The maximum TiO2 content in the magnetite lattice was 19%, only 8% of which was recovered to the magnetic product. Eventually, an iron concentration flow sheet was developed, which included the removal of a major part of silicates and then iron minerals by a low intensity wet magnetic separator. The final product contained 55, 7.8, and 0.77% of Fe, TiO2, and V2O5, respectively, which can be used for iron production, and V2O5 extraction (as the by-product).