Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale
| Autor: | Rongdong Deng, Adrian R. Muxworthy, Jiangang Ku, Weiran Zuo, Miguel A. Valdez-Grijalva, Qidi Chen, Hua Lin |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Magnetic structure Field (physics) Condensed matter physics lcsh:QE1-996.5 0211 other engineering and technologies micromagnetic modelling Field strength 02 engineering and technology 010502 geochemistry & geophysics 01 natural sciences irregular shaped particle Magnetic field lcsh:Geology Condensed Matter::Materials Science Magnetization chemistry.chemical_compound chemistry General Earth and Planetary Sciences Particle mineral extraction Micromagnetics 021102 mining & metallurgy 0105 earth and related environmental sciences Magnetite |
| Zdroj: | Geosciences, Vol 9, Iss 3, p 133 (2019) Geosciences Volume 9 Issue 3 |
| ISSN: | 2076-3263 |
| DOI: | 10.3390/geosciences9030133 |
| Popis: | We determine the role of particle shape in the type of magnetic extraction processes used in mining. We use a micromagnetic finite element method (FEM) to analyze the effect of external magnetic fields on the magnetic structures of sub-micron magnetite particles. In non-saturating fields, the magnetite particles contain multiple possible non-uniform magnetization states. The non-uniformity was found to gradually disappear with increasing applied field strength at 100 mT the domain structure became near uniform at 300 mT the magnetic structure saturates and the magnetization direction aligned with the field. In magnetic separation techniques, we suggest that 100 mT is the optimal field for magnetite to maximize the magnetic field with the lowest energy transfer larger particles, i.e., > 1 µ m, will likely saturate in smaller fields than this. We also examined the effect of external magnetic fields on a much larger irregular particle (L × W × H = 179.5 × 113 × 103 &mu m) that was too large to be examined using micromagnetics. To do this we used COMSOL. The results show the relative difference between the magnitude of magnetic flux density of the particle and that of a corresponding sphere of the same volume is < 5% when the distance to the particle geometry center is more than five times the sphere radius. The ideas developed in this paper have the potential to improve magnetic mineral extraction yield. |
| Databáze: | OpenAIRE |
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