# Particle-Scale Magnetic Susceptibility and Automated Mineralogy Dataset ## Overview This repository contains particle-scale mineralogical and magnetic susceptibility data generated to support geometallurgical analysis of magnetic separation processes. The dataset integrates experimental magnetic classification, bulk magnetic susceptibility measurements, and SEM-based automated mineralogical analysis (MLA). ## Sample Materials and Background The data were generated for both a natural ore (Norra Kärr) and a secondary resource (WEEE slag), covering multiple particle size fractions and levels of mineralogical complexity. --- ### Norra Kärr Ore The Norra Kärr material is a peralkaline nepheline syenite-hosted ore characterized by complex mineral assemblages and a high proportion of paramagnetic mineral phases. It is commonly studied in the context of rare earth element (REE)–bearing mineral systems and exhibits significant mineralogical heterogeneity at the particle scale. In this dataset, two particle size fractions of the Norra Kärr ore are included: - **NK1-3:** 500–1000 µm - **NK1-5:** 125–250 µm These fractions enable investigation of particle-size-dependent magnetic susceptibility variability, mineral associations, and separation behavior. Relevant background information on the Norra Kärr deposit and its mineralogical characteristics can be found in the following publications: - Atanasova P, Marks MAW, Heinig T, Krause J, Gutzmer J, Markl G. Distinguishing Magmatic and Metamorphic Processes in Peralkaline Rocks of the Norra Kärr Complex (Southern Sweden) Using Textural and Compositional Variations of Clinopyroxene and Eudialyte-group Minerals. J Petrology 2017;58(2):361–84. https://doi.org/10.1093/petrology/egx019. - Leißner T, Bachmann K, Gutzmer J, Peuker UA. MLA-based partition curves for magnetic separation. Minerals Engineering 2016;94:94–103. https://doi.org/10.1016/j.mineng.2016.05.015. These studies provide geological and mineralogical context for interpreting the magnetic and mineralogical data included in this repository. --- ### WEEE Slag The WEEE slag material represents a secondary resource derived from the processing of waste electrical and electronic equipment. Such slags are characterized by highly heterogeneous mineralogical assemblages, including metallic, oxide, silicate, and spinel-type phases, often with complex magnetic behavior. The particle size fraction included in this dataset is: - **63–100 µm** This material was selected to represent challenges commonly encountered in the magnetic separation of secondary resources, including overlapping magnetic responses, fine-grained mineral associations, and non-linear magnetic behavior caused by ferro- and ferrimagnetic phases. Background information on WEEE slag processing and resource recovery can be found in the following publications: - Siddique A, Boelens P, Long F, Zhou S, Cnudde V, Leißner T. Characterization of Magnetic and Mineralogical Properties of Slag Particles from WEEE Processing. Minerals 2023;13(11):1417. https://doi.org/10.3390/min13111417. - Buchmann M, Borowski N, Leißner T, Heinig T, Reuter MA, Friedrich B et al. Evaluation of Recyclability of a WEEE Slag by Means of Integrative X-Ray Computer Tomography and SEM-Based Image Analysis. Minerals 2020;10(4):309. https://doi.org/10.3390/min10040309. These references provide broader context for the mineralogical complexity and processing relevance of WEEE-derived materials. --- ## Relevance of the Materials Together, the Norra Kärr ore and WEEE slag samples represent: - A **primary mineral resource** with geological heterogeneity - A **secondary resource** with complex, anthropogenic phase assemblages The combination enables comparative analysis of magnetic susceptibility behavior across fundamentally different material systems and supports the development and validation of particle-scale, geometallurgical approaches to magnetic separation. --- ## Dataset Structure /Dataset_Root │── README.md │ ├── Norra Karr Ore/ │ └── NK1-3/ │ └── NK1-5/ │ └── NK1-5_Feed/ │ └── README.md │ ├── WEEE_Slag/ │ └── README.md Each sample folder contains all magnetic susceptibility and MLA data related to that specific material and particle size fraction, along with a dedicated README file. --- ## Data Types Included - Magnetic susceptibility measurements of Frantz susceptibility classes - SEM-based automated mineralogy (MLA) data at class and particle scales ## Measurement Facilities and Equipment The data contained in this repository were generated using a combination of magnetic separation equipment, magnetic susceptibility measurement devices, and SEM-based automated mineralogical analysis systems. Measurements were performed at established academic research facilities with dedicated instrumentation for mineral processing and materials characterization. ### Magnetic Separation and Susceptibility Measurements Magnetic classification of particulate samples was performed using a **Frantz Isodynamic Separator** (in-house built), which enables separation of particles into discrete magnetic susceptibility classes by varying the applied current and chute conditions. Bulk magnetic susceptibility measurements of the resulting classes were conducted using a **Magnetic Susceptibility Balance (MSB Auto 2, Sherwood Scientific Ltd., Cambridge, UK)**, providing class-average susceptibility values under controlled laboratory conditions. These measurements were carried out at the **Institute of Mechanical Process Engineering and Mineral Processing, TU Bergakademie Freiberg (Germany)**. Information about the institute and its research infrastructure can be found at: - https://tu-freiberg.de/fakult4/mvtat --- ### SEM-Based Automated Mineralogy (MLA) Quantitative mineralogical characterization was performed using **SEM-based Mineral Liberation Analysis (MLA)**, which combines scanning electron microscopy with energy-dispersive X-ray spectroscopy to determine mineral phase distributions at both class and particle scales. MLA measurements were conducted at the following facilities: - **Helmholtz Institute Freiberg for Resource Technology (HIF), Germany** for Norra Kärr ore samples https://www.hzdr.de/db/Cms?pOid=40452&pNid=1524&pLang=en - **Institute of Mineralogy, TU Bergakademie Freiberg, Germany** for WEEE slag samples https://tu-freiberg.de/fakult3/min/econgeology/labore/geometallurgielabor These facilities provide dedicated SEM-MLA infrastructure for quantitative mineralogical and geometallurgical investigations. --- ## Notes on Measurement Context All measurements were performed on representative particle mounts prepared according to standard mineral processing and automated mineralogy protocols. The combination of magnetic classification, bulk susceptibility measurement, and MLA enables correlative analysis of magnetic response and mineralogical composition at multiple scales. ## Data prepared for Publication Further details on the experimental methodology, data analysis, and interpretation of the results derived from this dataset are provided in the following publication: *A Workflow for Particle-Scale Magnetic Susceptibility Estimation as a Geometallurgical Tool for Magnetic Separation.* The manuscript describes how the magnetic susceptibility measurements and automated mineralogical data contained in this repository were used to estimate particle-scale magnetic susceptibility and to investigate magnetic separation behavior. --- ## Intended Use The dataset is suitable for: - Magnetic separation studies - Particle-based mineral processing research - Geometallurgical analysis - Development and validation of data-driven characterization methods --- ## Notes - Magnetic susceptibility values are class-average measurements. - MLA data are derived from two-dimensional polished sections and may be subject to stereological effects. - Users are encouraged to consult the README file in each sample folder for sample-specific details.