Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale
Shales are increasingly being exploited for oil and unconventional gas. Exploitation of sub-arctic oil shales requires the creation of gravel pads to elevate workings above the heaving effects of ground ice. These gravel pads can potentially generate acidic leachate, which can enhance the mobility o...
Published in: | Minerals |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
MDPI AG
2014
|
Subjects: | |
Online Access: | https://doi.org/10.3390/min4020293 https://doaj.org/article/3369e962c43941ce89ac35ca480e78eb |
id |
ftdoajarticles:oai:doaj.org/article:3369e962c43941ce89ac35ca480e78eb |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:3369e962c43941ce89ac35ca480e78eb 2023-05-15T14:54:19+02:00 Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale Kathryn A. Mumford Brendan Pitt Ashley T. Townsend Ian Snape Damian B. Gore 2014-04-01T00:00:00Z https://doi.org/10.3390/min4020293 https://doaj.org/article/3369e962c43941ce89ac35ca480e78eb EN eng MDPI AG http://www.mdpi.com/2075-163X/4/2/293 https://doaj.org/toc/2075-163X 2075-163X doi:10.3390/min4020293 https://doaj.org/article/3369e962c43941ce89ac35ca480e78eb Minerals, Vol 4, Iss 2, Pp 293-312 (2014) acid rock drainage pH oxidation reduction potential metal concentration total reflection X-ray fluorescence spectrometry (TRXRF) Mineralogy QE351-399.2 article 2014 ftdoajarticles https://doi.org/10.3390/min4020293 2022-12-31T02:51:16Z Shales are increasingly being exploited for oil and unconventional gas. Exploitation of sub-arctic oil shales requires the creation of gravel pads to elevate workings above the heaving effects of ground ice. These gravel pads can potentially generate acidic leachate, which can enhance the mobility of metals from the shale. To examine this potential, pyrite-bearing shale originating from sub-Arctic gravel pad sites were subjected to leaching tests for 600 days at initial pH values ranging from 2 to 5, to simulate potential real world conditions. At set times over the 600 day experiment, pH, oxidation reduction potential (ORP), dissolved oxygen and temperature were recorded and small liquid samples withdrawn and analysed for elemental concentrations using total reflection X-ray fluorescence spectrometry (TRXRF). Six of eight shale samples were found to be acid generating, with pH declining and ORP becoming increasingly positive after 100 days. Two of the eight shale samples produced increasingly alkaline leachate conditions with relatively low ORP after 100 days, indicating an inbuilt buffering capacity. By 600 days the buffering capacity of all samples had been consumed and all leachate samples were acidic. TRXRF analyses demonstrated significant potential for the leaching of S, Fe, Ni, Cu, Zn and Mn with greatest concentrations found in reaction vessels with most acidic pH and highest ORP. Article in Journal/Newspaper Arctic Directory of Open Access Journals: DOAJ Articles Arctic Minerals 4 2 293 312 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
acid rock drainage pH oxidation reduction potential metal concentration total reflection X-ray fluorescence spectrometry (TRXRF) Mineralogy QE351-399.2 |
spellingShingle |
acid rock drainage pH oxidation reduction potential metal concentration total reflection X-ray fluorescence spectrometry (TRXRF) Mineralogy QE351-399.2 Kathryn A. Mumford Brendan Pitt Ashley T. Townsend Ian Snape Damian B. Gore Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
topic_facet |
acid rock drainage pH oxidation reduction potential metal concentration total reflection X-ray fluorescence spectrometry (TRXRF) Mineralogy QE351-399.2 |
description |
Shales are increasingly being exploited for oil and unconventional gas. Exploitation of sub-arctic oil shales requires the creation of gravel pads to elevate workings above the heaving effects of ground ice. These gravel pads can potentially generate acidic leachate, which can enhance the mobility of metals from the shale. To examine this potential, pyrite-bearing shale originating from sub-Arctic gravel pad sites were subjected to leaching tests for 600 days at initial pH values ranging from 2 to 5, to simulate potential real world conditions. At set times over the 600 day experiment, pH, oxidation reduction potential (ORP), dissolved oxygen and temperature were recorded and small liquid samples withdrawn and analysed for elemental concentrations using total reflection X-ray fluorescence spectrometry (TRXRF). Six of eight shale samples were found to be acid generating, with pH declining and ORP becoming increasingly positive after 100 days. Two of the eight shale samples produced increasingly alkaline leachate conditions with relatively low ORP after 100 days, indicating an inbuilt buffering capacity. By 600 days the buffering capacity of all samples had been consumed and all leachate samples were acidic. TRXRF analyses demonstrated significant potential for the leaching of S, Fe, Ni, Cu, Zn and Mn with greatest concentrations found in reaction vessels with most acidic pH and highest ORP. |
format |
Article in Journal/Newspaper |
author |
Kathryn A. Mumford Brendan Pitt Ashley T. Townsend Ian Snape Damian B. Gore |
author_facet |
Kathryn A. Mumford Brendan Pitt Ashley T. Townsend Ian Snape Damian B. Gore |
author_sort |
Kathryn A. Mumford |
title |
Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
title_short |
Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
title_full |
Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
title_fullStr |
Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
title_full_unstemmed |
Long-Term Acid-Generating and Metal Leaching Potential of a Sub-Arctic Oil Shale |
title_sort |
long-term acid-generating and metal leaching potential of a sub-arctic oil shale |
publisher |
MDPI AG |
publishDate |
2014 |
url |
https://doi.org/10.3390/min4020293 https://doaj.org/article/3369e962c43941ce89ac35ca480e78eb |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic |
genre_facet |
Arctic |
op_source |
Minerals, Vol 4, Iss 2, Pp 293-312 (2014) |
op_relation |
http://www.mdpi.com/2075-163X/4/2/293 https://doaj.org/toc/2075-163X 2075-163X doi:10.3390/min4020293 https://doaj.org/article/3369e962c43941ce89ac35ca480e78eb |
op_doi |
https://doi.org/10.3390/min4020293 |
container_title |
Minerals |
container_volume |
4 |
container_issue |
2 |
container_start_page |
293 |
op_container_end_page |
312 |
_version_ |
1766326031346565120 |