Thermomagnetic Study for Identification of Mineral Phases

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.

材料表征（materials characterization）是工程领域极具核心意义的研究方向，其依托一系列仪器分析技术，为材料分析与选材构建完备的信息数据库。在铁矿石选矿流程中，矿物学表征（mineralogical characterization）几乎完全依靠光学显微分析完成。但对于粒径小于4微米（µm）的超细颗粒材料，该设备难以实现样品的有效制备与观测。本研究采用Bartington MS3磁化率（magnetic susceptibility）测试仪，通过测试磁化率随温度的变化关系，对铁矿石选矿尾矿样品中的赤铁矿（Hematite）、磁铁矿（Magnetite）与针铁矿（Goethite）进行定性识别。该测试方法可通过特征居里温度（Curie Temperature）识别磁铁矿（580℃）与赤铁矿（675℃），并通过奈耳温度（Neel Temperature，120℃）完成针铁矿的识别。研究结果表明，该技术在载磁矿物识别与样品磁潜能量化方面具有极高应用价值。