Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures
Acid-generating sulphidic tailings from a NiCu mine were exposed on the shores of Hudson Bay for 30 years before burial in a drained bedrock basin. To determine if encapsulation in permafrost will maintain the tailings, and their saline pore water, in a chemically inert state, a field and experimen...
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crcansciencepubl:10.1139/t01-028 2024-09-15T18:11:04+00:00 Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures Meldrum, J L Jamieson, H E Dyke, L D 2001 http://dx.doi.org/10.1139/t01-028 http://www.nrcresearchpress.com/doi/pdf/10.1139/t01-028 en eng Canadian Science Publishing http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining Canadian Geotechnical Journal volume 38, issue 5, page 957-966 ISSN 0008-3674 1208-6010 journal-article 2001 crcansciencepubl https://doi.org/10.1139/t01-028 2024-07-18T04:13:34Z Acid-generating sulphidic tailings from a NiCu mine were exposed on the shores of Hudson Bay for 30 years before burial in a drained bedrock basin. To determine if encapsulation in permafrost will maintain the tailings, and their saline pore water, in a chemically inert state, a field and experimental program was employed. Three years after burial, several boreholes were drilled to collect tailings and pore-water samples and to initiate long-term thermal monitoring. Columns charged with pyrrhotite-bearing, unsaturated tailings were studied at temperatures between +30°C and 10°C. Oxygen consumption was measured directly to determine the effect of low temperatures on oxidation rate. Results of the column experiments indicate that significant oxidation of the Rankin Inlet tailings occurs at +30°C, but at lower temperatures this rate is substantially reduced. At 10°C, unfrozen water was still present in the columns, but oxygen consumption was below the detection limit. The highest measured oxygen flux correlates with a temperature increase of 1°C, consistent with exothermic sulphide oxidation reactions. Thermal modeling and direct measurements have shown that the freezing of the tailings in Rankin Inlet is progressing. The tailings are expected to be ice-bonded approximately 15 years after burial.Key words: acid mine drainage, permafrost, tailings, reclamation, sulphides, oxidation Article in Journal/Newspaper Hudson Bay Ice Nunavut permafrost Rankin Inlet Canadian Science Publishing Canadian Geotechnical Journal 38 5 957 966 |
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Canadian Science Publishing |
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English |
description |
Acid-generating sulphidic tailings from a NiCu mine were exposed on the shores of Hudson Bay for 30 years before burial in a drained bedrock basin. To determine if encapsulation in permafrost will maintain the tailings, and their saline pore water, in a chemically inert state, a field and experimental program was employed. Three years after burial, several boreholes were drilled to collect tailings and pore-water samples and to initiate long-term thermal monitoring. Columns charged with pyrrhotite-bearing, unsaturated tailings were studied at temperatures between +30°C and 10°C. Oxygen consumption was measured directly to determine the effect of low temperatures on oxidation rate. Results of the column experiments indicate that significant oxidation of the Rankin Inlet tailings occurs at +30°C, but at lower temperatures this rate is substantially reduced. At 10°C, unfrozen water was still present in the columns, but oxygen consumption was below the detection limit. The highest measured oxygen flux correlates with a temperature increase of 1°C, consistent with exothermic sulphide oxidation reactions. Thermal modeling and direct measurements have shown that the freezing of the tailings in Rankin Inlet is progressing. The tailings are expected to be ice-bonded approximately 15 years after burial.Key words: acid mine drainage, permafrost, tailings, reclamation, sulphides, oxidation |
format |
Article in Journal/Newspaper |
author |
Meldrum, J L Jamieson, H E Dyke, L D |
spellingShingle |
Meldrum, J L Jamieson, H E Dyke, L D Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
author_facet |
Meldrum, J L Jamieson, H E Dyke, L D |
author_sort |
Meldrum, J L |
title |
Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
title_short |
Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
title_full |
Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
title_fullStr |
Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
title_full_unstemmed |
Oxidation of mine tailings from Rankin Inlet, Nunavut, at subzero temperatures |
title_sort |
oxidation of mine tailings from rankin inlet, nunavut, at subzero temperatures |
publisher |
Canadian Science Publishing |
publishDate |
2001 |
url |
http://dx.doi.org/10.1139/t01-028 http://www.nrcresearchpress.com/doi/pdf/10.1139/t01-028 |
genre |
Hudson Bay Ice Nunavut permafrost Rankin Inlet |
genre_facet |
Hudson Bay Ice Nunavut permafrost Rankin Inlet |
op_source |
Canadian Geotechnical Journal volume 38, issue 5, page 957-966 ISSN 0008-3674 1208-6010 |
op_rights |
http://www.nrcresearchpress.com/page/about/CorporateTextAndDataMining |
op_doi |
https://doi.org/10.1139/t01-028 |
container_title |
Canadian Geotechnical Journal |
container_volume |
38 |
container_issue |
5 |
container_start_page |
957 |
op_container_end_page |
966 |
_version_ |
1810448668190310400 |