Hematite from a mining area in the east border of Quadrilátero Ferrífero, Minas Gerais, Brazil

Abstract

Iron oxides are dominant minerals in many geo-domains of economical interest, as iron ore mines. Knowing the main mineral transformation pathways is a fundamental step to plan prospecting new mineral deposits. This study aimed at contributing to a better understanding of the chemical and mineralogical processes related to the genesis and transformations of iron oxides involving hematite in an iron-ore mine of the east border of Quadrilátero Ferrífero, Minas Gerais, Brazil. Two representative geo-samples were analyzed with synchrotron radiation X-ray diffraction (XRD), 57 Fe Mössbauer spectroscopy, X-ray fluorescence and saturation magnetization (σ ) measurements. The iron content varied from 65 to 69 mass% Fe. From XRD data, hematite is indeed the major mineral for all samples but characteristic reflections of goethite and magnetite also appear. For the magnetic A.R.P. Pereira et al.sample, σ = 6.9 J T −1 kg −1 . 298 K-and 110 K-Mössbauer data allow characterizing hematite in these iron-rich geo-materials.