Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget
Laboratory magnetic measurements are used to develop a methodology to characterize the Kiruna-type Rare Earth Elements (REE) bearing apatite iron-oxide deposits at Blötberget in central Sweden. This high-grade ore deposit is known to have sharp boundaries between lens shaped main ore bodies of magne...
Main Author: | |
---|---|
Format: | Bachelor Thesis |
Language: | English |
Published: |
Uppsala universitet, Geofysik
2018
|
Subjects: | |
Online Access: | http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975 |
id |
ftuppsalauniv:oai:DiVA.org:uu-347975 |
---|---|
record_format |
openpolar |
spelling |
ftuppsalauniv:oai:DiVA.org:uu-347975 2023-05-15T17:04:20+02:00 Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget Karaktärisering av magnetisk susceptibilitet och remanens hos magnetit och hematitrika borrkärnor från Blötberget Bjork, Andreas 2018 application/pdf http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975 eng eng Uppsala universitet, Geofysik Examensarbete vid Institutionen för geovetenskaper, 1650-6553 424 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975 info:eu-repo/semantics/openAccess Verwey Morin Curie Néel magnetite hematite alteration iron-ore quality control kappabridge hysteresis susceptibility anisotropy magnetit hematit oxidation järnmalm kvalitetskontroll susceptibilitet anisotropi Geophysics Geofysik Student thesis info:eu-repo/semantics/bachelorThesis text 2018 ftuppsalauniv 2023-02-23T21:47:21Z Laboratory magnetic measurements are used to develop a methodology to characterize the Kiruna-type Rare Earth Elements (REE) bearing apatite iron-oxide deposits at Blötberget in central Sweden. This high-grade ore deposit is known to have sharp boundaries between lens shaped main ore bodies of magnetite-rich ore, and a complex hematite-rich ore associated with pegmatites and skarn formation. The thesis covers laboratory magnetic measurements of 37 samples originating from eight drill cores and reference samples from previously mined area. It focuses on on-covering how the samples relate in terms of magnetic susceptibility, further its dependency on temperature, frequency, field and the orientation. The results are correlated with petrographic analysis previously performed on accompanying thin sections. The measurements show that magnetite with strong susceptibility contribution overshadow the hematite contribution in the samples. Transition changes in susceptibility are noticeable when crossing the Verwey temperature; -153°C, Curie temperature; 580°C and Néel temperature; 680°C. The Morin temperature appears at -60°C, or is missing. Linear relationships are identified between the magnitude difference in susceptibilities across transitions at high temperature and wt% magnetite and hematite have been identified. The Blötberget skarn and hematite-rich ore samples have a higher degree of susceptibility anisotropy than the other ore-types. Blötberget samples are dominated by multidomain characteristics in remanence, saturation and coercivity. High temperature measurements have shown that the magnetite is close to pure. The low temperature measurements suggest hematite is impure or bears a petrological footprint. The study also shows that rich iron ore samples sometimes can be at risk of being overlooked with standard methods of measuring susceptibility Laboratorietekniska metoder kan användas som ett komplement till malmgeologi och geofysisk prospektering. I denna metodstudie karaktäriseras apatitjärnmalm från ... Bachelor Thesis Kiruna Uppsala University: Publications (DiVA) Kiruna |
institution |
Open Polar |
collection |
Uppsala University: Publications (DiVA) |
op_collection_id |
ftuppsalauniv |
language |
English |
topic |
Verwey Morin Curie Néel magnetite hematite alteration iron-ore quality control kappabridge hysteresis susceptibility anisotropy magnetit hematit oxidation järnmalm kvalitetskontroll susceptibilitet anisotropi Geophysics Geofysik |
spellingShingle |
Verwey Morin Curie Néel magnetite hematite alteration iron-ore quality control kappabridge hysteresis susceptibility anisotropy magnetit hematit oxidation järnmalm kvalitetskontroll susceptibilitet anisotropi Geophysics Geofysik Bjork, Andreas Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
topic_facet |
Verwey Morin Curie Néel magnetite hematite alteration iron-ore quality control kappabridge hysteresis susceptibility anisotropy magnetit hematit oxidation järnmalm kvalitetskontroll susceptibilitet anisotropi Geophysics Geofysik |
description |
Laboratory magnetic measurements are used to develop a methodology to characterize the Kiruna-type Rare Earth Elements (REE) bearing apatite iron-oxide deposits at Blötberget in central Sweden. This high-grade ore deposit is known to have sharp boundaries between lens shaped main ore bodies of magnetite-rich ore, and a complex hematite-rich ore associated with pegmatites and skarn formation. The thesis covers laboratory magnetic measurements of 37 samples originating from eight drill cores and reference samples from previously mined area. It focuses on on-covering how the samples relate in terms of magnetic susceptibility, further its dependency on temperature, frequency, field and the orientation. The results are correlated with petrographic analysis previously performed on accompanying thin sections. The measurements show that magnetite with strong susceptibility contribution overshadow the hematite contribution in the samples. Transition changes in susceptibility are noticeable when crossing the Verwey temperature; -153°C, Curie temperature; 580°C and Néel temperature; 680°C. The Morin temperature appears at -60°C, or is missing. Linear relationships are identified between the magnitude difference in susceptibilities across transitions at high temperature and wt% magnetite and hematite have been identified. The Blötberget skarn and hematite-rich ore samples have a higher degree of susceptibility anisotropy than the other ore-types. Blötberget samples are dominated by multidomain characteristics in remanence, saturation and coercivity. High temperature measurements have shown that the magnetite is close to pure. The low temperature measurements suggest hematite is impure or bears a petrological footprint. The study also shows that rich iron ore samples sometimes can be at risk of being overlooked with standard methods of measuring susceptibility Laboratorietekniska metoder kan användas som ett komplement till malmgeologi och geofysisk prospektering. I denna metodstudie karaktäriseras apatitjärnmalm från ... |
format |
Bachelor Thesis |
author |
Bjork, Andreas |
author_facet |
Bjork, Andreas |
author_sort |
Bjork, Andreas |
title |
Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
title_short |
Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
title_full |
Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
title_fullStr |
Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
title_full_unstemmed |
Characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at Blötberget |
title_sort |
characterizing magnetic susceptibility and remanent magnetization of magnetite and hematite rich drill-core samples at blötberget |
publisher |
Uppsala universitet, Geofysik |
publishDate |
2018 |
url |
http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975 |
geographic |
Kiruna |
geographic_facet |
Kiruna |
genre |
Kiruna |
genre_facet |
Kiruna |
op_relation |
Examensarbete vid Institutionen för geovetenskaper, 1650-6553 424 http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-347975 |
op_rights |
info:eu-repo/semantics/openAccess |
_version_ |
1766058413765165056 |