Electrical properties and mineralogical investigation of Egyptian iron ore deposits

Electrical properties and X-ray diffraction of 20 hematite sandstone samples of the most economically interesting Egyptian iron ore deposits have been investigated. Samples were collected from two different areas in Egypt (Aswan and Bahariya). Complex impedance measurements in the frequency range from 10 Hz to 100 kHz were performed at room temperature (∼20 °C). The observed dielectric behavior was characterized by Maxwell–Wagner interfacial polarization at low frequencies and bulk polarization at relatively higher frequencies. The frequency dependence on conductivity shows a classical relaxation behavior followed Jonscher’s universal law. The measured electrical properties vary strongly with the frequency and sample composition. The difference in the electrical properties may be attributed to the fluctuations in the concentration of the sample constituents and to the degree of heterogeneity of the grains. The XRD-patterns of Egyptian iron ore deposits prove that the main phases are hematite and quartz.