The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories
Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-28 11:06:41.351 Increased demand for rare earth elements (REEs) for applications in modern technologies has led to an increase in REE exploration. Several deposits are expected to begin mining withi...
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ftqueensuniv:oai:https://qspace.library.queensu.ca:1974/12206 2024-06-02T08:12:19+00:00 The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories Purdy, Colin Geological Sciences and Geological Engineering Jamieson, Heather E. 2014-05-28 11:06:41.351 application/pdf http://hdl.handle.net/1974/12206 eng eng Canadian theses http://hdl.handle.net/1974/12206 This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. Geochemistry Speciation Sorption Rare Earth Elements Colloids PHREEQC Lanthanides MLA Synchrotron Tailings Mine Waste Aqueous Mobility thesis 2014 ftqueensuniv 2024-05-06T10:47:32Z Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-28 11:06:41.351 Increased demand for rare earth elements (REEs) for applications in modern technologies has led to an increase in REE exploration. Several deposits are expected to begin mining within a decade, but few studies have examined the possible environmental effects created by these mines. Metal toxicity is thought to be greater in aqueous environments when metals occur as free ions rather than complexes, and the speciation can also impact the treatment technologies utilized to reduce metal concentrations. This research investigates the mineralogical source of REEs and the mechanism of REE mobility in low-temperature waters that have interacted with pilot plant tailings from the Nechalacho deposit, Northwest Territories. The Nechalacho deposit is owned by Avalon Rare Metals Inc. and located approximately 100 km east of Yellowknife. The deposit is hosted within a hydrothermally altered layered nepheline-sodalite syenite in the peralkaline Blatchford Lake complex. The main REE ore minerals are zircon, fergusonite, allanite, monazite, bastnäsite, and synchisite-parasite. Characterization of the tailings using mineral liberation analyzer (MLA) show that the ore minerals are fine grained and well liberated. Bastnäsite and synchisite-parasite are the only potentially soluble ore minerals at low temperature and near-neutral pH. Shake flask experiments were designed to simulate the interaction of tailings with three different leach waters to identify soluble phases and mobile elements. Decanted solutions from the shake flasks were filtered to 0.45µm and 0.01µm. Speciation modelling of the 0.01µm filtrate suggests that carbonate ligands will form the dominant complexes with the REEs, and <2% occur as free metal ions. Higher proportions of LREEs (1-6%) occur as free metal ions than HREEs (<1%) and LREEs occur in higher concentrations (2 to 8 times greater) than the HREE. REEs were found in the colloidal ... Thesis Northwest Territories Yellowknife Queen's University, Ontario: QSpace Northwest Territories Yellowknife Blatchford Lake ENVELOPE(-112.584,-112.584,62.184,62.184) |
institution |
Open Polar |
collection |
Queen's University, Ontario: QSpace |
op_collection_id |
ftqueensuniv |
language |
English |
topic |
Geochemistry Speciation Sorption Rare Earth Elements Colloids PHREEQC Lanthanides MLA Synchrotron Tailings Mine Waste Aqueous Mobility |
spellingShingle |
Geochemistry Speciation Sorption Rare Earth Elements Colloids PHREEQC Lanthanides MLA Synchrotron Tailings Mine Waste Aqueous Mobility Purdy, Colin The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
topic_facet |
Geochemistry Speciation Sorption Rare Earth Elements Colloids PHREEQC Lanthanides MLA Synchrotron Tailings Mine Waste Aqueous Mobility |
description |
Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2014-05-28 11:06:41.351 Increased demand for rare earth elements (REEs) for applications in modern technologies has led to an increase in REE exploration. Several deposits are expected to begin mining within a decade, but few studies have examined the possible environmental effects created by these mines. Metal toxicity is thought to be greater in aqueous environments when metals occur as free ions rather than complexes, and the speciation can also impact the treatment technologies utilized to reduce metal concentrations. This research investigates the mineralogical source of REEs and the mechanism of REE mobility in low-temperature waters that have interacted with pilot plant tailings from the Nechalacho deposit, Northwest Territories. The Nechalacho deposit is owned by Avalon Rare Metals Inc. and located approximately 100 km east of Yellowknife. The deposit is hosted within a hydrothermally altered layered nepheline-sodalite syenite in the peralkaline Blatchford Lake complex. The main REE ore minerals are zircon, fergusonite, allanite, monazite, bastnäsite, and synchisite-parasite. Characterization of the tailings using mineral liberation analyzer (MLA) show that the ore minerals are fine grained and well liberated. Bastnäsite and synchisite-parasite are the only potentially soluble ore minerals at low temperature and near-neutral pH. Shake flask experiments were designed to simulate the interaction of tailings with three different leach waters to identify soluble phases and mobile elements. Decanted solutions from the shake flasks were filtered to 0.45µm and 0.01µm. Speciation modelling of the 0.01µm filtrate suggests that carbonate ligands will form the dominant complexes with the REEs, and <2% occur as free metal ions. Higher proportions of LREEs (1-6%) occur as free metal ions than HREEs (<1%) and LREEs occur in higher concentrations (2 to 8 times greater) than the HREE. REEs were found in the colloidal ... |
author2 |
Geological Sciences and Geological Engineering Jamieson, Heather E. |
format |
Thesis |
author |
Purdy, Colin |
author_facet |
Purdy, Colin |
author_sort |
Purdy, Colin |
title |
The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
title_short |
The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
title_full |
The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
title_fullStr |
The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
title_full_unstemmed |
The Geochemical and Mineralogical Controls on the Environmental Mobility of Rare Earth Elements From Tailings, Nechalacho Deposit, Northwest Territories |
title_sort |
geochemical and mineralogical controls on the environmental mobility of rare earth elements from tailings, nechalacho deposit, northwest territories |
publishDate |
2014 |
url |
http://hdl.handle.net/1974/12206 |
long_lat |
ENVELOPE(-112.584,-112.584,62.184,62.184) |
geographic |
Northwest Territories Yellowknife Blatchford Lake |
geographic_facet |
Northwest Territories Yellowknife Blatchford Lake |
genre |
Northwest Territories Yellowknife |
genre_facet |
Northwest Territories Yellowknife |
op_relation |
Canadian theses http://hdl.handle.net/1974/12206 |
op_rights |
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
_version_ |
1800758707004375040 |