Thermomagnetic Study for Identification of Mineral Phases

Abstract

The characterization of materials is an area of extreme importance for engineering, it uses a range of instrumental techniques to provide an information bank for material analysis and selection. In the treatment of iron ore the mineralogical characterization is done, almost exclusively, by optical microscopy. However, materials with very fine granulometry, below 4 μm, make their preparation and visualization restricted in this equipment. The present work aims to identify the minerals Hematite, Magnetite and Goethite in samples of tailings from the iron ore processing, employing a Bartington MS3 that evaluates the magnetic susceptibility as a function of the temperature. These measurements make it possible to identify Curie temperatures characteristic of Magnetite (580 °C) and Hematite (675 °C), as well as Goethite's Neel temperature (120 °C). The results showed that the application of the technique is of great value for the identification of the magnetic bearing minerals and the quantification of the magnetic potential of the sample.

A multi-analytical methodology for the characterization of industrial samples of spent Ni-MH battery powders

“…2) b)). Hematite is anti-ferromagnetic and has a Neel temperature of 675°C (Cunha et al, 2017) which is above the maximum temperature used during the susceptibility measurements. However, the presence of Fe 2 O 3 could justify the remaining mass magnetic susceptibility of 300 cm 3 /g at 600°C (Fig.…”