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Title: The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT

Abstract

Approximately 20,000 tonnes of arsenic (As)-bearing emissions from roasting gold (Au)-bearing arsenopyrite ore were aerially released from 1949 to 1999 at Giant Mine, near Yellowknife, Canada. Soil samples collected within 4 km of the former roaster from sites undisturbed by mining or other human activity contain up to 7700 mg/kg total As. Total As concentrations are highest within a few cm of the surface, and particularly enriched in soil pockets on rock outcrops. Scanning electron microscopy and synchrotron microanalysis show that roaster-derived arsenic trioxide (As2O3) has persisted in shallow soils in the area. Roaster-generated maghemite and hematite are also present. These anthropogenic forms of As are much more common in near-surface soils than natural As-bearing minerals. Comparison of the proportions of As, Sb, and Au concentrations in outcrop soil samples and historic As2O3-rich dust captured by emission controls suggest most of the roaster-derived As in soils at Giant was likely deposited before 1964. Topographic restriction by rock outcrops and a dry, cold climate likely contribute to the persistence of As2O3 in outcrop soils.

Authors:
ORCiD logo; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1409624
Report Number(s):
BNL-114676-2017-JA¿¿¿
Journal ID: ISSN 0883-2927
DOE Contract Number:
SC0012704
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Geochemistry; Journal Volume: 82; Journal Issue: C
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Bromstad, Mackenzie J., Wrye, Lori A., and Jamieson, Heather E. The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT. United States: N. p., 2017. Web. doi:10.1016/j.apgeochem.2017.04.004.
Bromstad, Mackenzie J., Wrye, Lori A., & Jamieson, Heather E. The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT. United States. doi:10.1016/j.apgeochem.2017.04.004.
Bromstad, Mackenzie J., Wrye, Lori A., and Jamieson, Heather E. 2017. "The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT". United States. doi:10.1016/j.apgeochem.2017.04.004.
@article{osti_1409624,
title = {The characterization, mobility, and persistence of roaster-derived arsenic in soils at Giant Mine, NWT},
author = {Bromstad, Mackenzie J. and Wrye, Lori A. and Jamieson, Heather E.},
abstractNote = {Approximately 20,000 tonnes of arsenic (As)-bearing emissions from roasting gold (Au)-bearing arsenopyrite ore were aerially released from 1949 to 1999 at Giant Mine, near Yellowknife, Canada. Soil samples collected within 4 km of the former roaster from sites undisturbed by mining or other human activity contain up to 7700 mg/kg total As. Total As concentrations are highest within a few cm of the surface, and particularly enriched in soil pockets on rock outcrops. Scanning electron microscopy and synchrotron microanalysis show that roaster-derived arsenic trioxide (As2O3) has persisted in shallow soils in the area. Roaster-generated maghemite and hematite are also present. These anthropogenic forms of As are much more common in near-surface soils than natural As-bearing minerals. Comparison of the proportions of As, Sb, and Au concentrations in outcrop soil samples and historic As2O3-rich dust captured by emission controls suggest most of the roaster-derived As in soils at Giant was likely deposited before 1964. Topographic restriction by rock outcrops and a dry, cold climate likely contribute to the persistence of As2O3 in outcrop soils.},
doi = {10.1016/j.apgeochem.2017.04.004},
journal = {Applied Geochemistry},
number = C,
volume = 82,
place = {United States},
year = 2017,
month = 7
}
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