Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale
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 magnet...
Main Authors: | , , , , , , |
---|---|
Format: | Article |
Language: | English |
Published: |
MDPI AG
2019-03-01
|
Series: | Geosciences |
Subjects: | |
Online Access: | http://www.mdpi.com/2076-3263/9/3/133 |
id |
doaj-0466a8064f184043a82cbf43183f10f0 |
---|---|
record_format |
Article |
spelling |
doaj-0466a8064f184043a82cbf43183f10f02020-11-25T00:55:11ZengMDPI AGGeosciences2076-32632019-03-019313310.3390/geosciences9030133geosciences9030133Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-ScaleJiangang Ku0Miguel A. Valdez-Grijalva1Rongdong Deng2Weiran Zuo3Qidi Chen4Hua Lin5Adrian R. Muxworthy6School of Zijin Mine, Fuzhou University, Fuzhou 350116, ChinaNatural Magnetism Group, Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UKSchool of Zijin Mine, Fuzhou University, Fuzhou 350116, ChinaSchool of Zijin Mine, Fuzhou University, Fuzhou 350116, ChinaSchool of Zijin Mine, Fuzhou University, Fuzhou 350116, ChinaSchool of Zijin Mine, Fuzhou University, Fuzhou 350116, ChinaNatural Magnetism Group, Department of Earth Science and Engineering, Imperial College London, London SW7 2AZ, UKWe 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 µm, 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 μm) 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.http://www.mdpi.com/2076-3263/9/3/133micromagnetic modellingmineral extractionirregular shaped particle |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Jiangang Ku Miguel A. Valdez-Grijalva Rongdong Deng Weiran Zuo Qidi Chen Hua Lin Adrian R. Muxworthy |
spellingShingle |
Jiangang Ku Miguel A. Valdez-Grijalva Rongdong Deng Weiran Zuo Qidi Chen Hua Lin Adrian R. Muxworthy Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale Geosciences micromagnetic modelling mineral extraction irregular shaped particle |
author_facet |
Jiangang Ku Miguel A. Valdez-Grijalva Rongdong Deng Weiran Zuo Qidi Chen Hua Lin Adrian R. Muxworthy |
author_sort |
Jiangang Ku |
title |
Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale |
title_short |
Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale |
title_full |
Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale |
title_fullStr |
Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale |
title_full_unstemmed |
Modelling External Magnetic Fields of Magnetite Particles: From Micro- to Macro-Scale |
title_sort |
modelling external magnetic fields of magnetite particles: from micro- to macro-scale |
publisher |
MDPI AG |
series |
Geosciences |
issn |
2076-3263 |
publishDate |
2019-03-01 |
description |
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 µm, 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 μm) 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. |
topic |
micromagnetic modelling mineral extraction irregular shaped particle |
url |
http://www.mdpi.com/2076-3263/9/3/133 |
work_keys_str_mv |
AT jiangangku modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT miguelavaldezgrijalva modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT rongdongdeng modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT weiranzuo modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT qidichen modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT hualin modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale AT adrianrmuxworthy modellingexternalmagneticfieldsofmagnetiteparticlesfrommicrotomacroscale |
_version_ |
1725231553270775808 |