Geochemical assessments and classification of coal mine spoils for better understanding of potential salinity issues at closure

Park, Jin Hee, Li, Xiaofang, Edraki, Mansour, Baumgartl, Thomas and Kirsch, Bernie (2013) Geochemical assessments and classification of coal mine spoils for better understanding of potential salinity issues at closure. Environmental Science Processes and Impacts, 15 6: 1235-1244. doi:10.1039/C3EM30672K

Author Park, Jin Hee
Li, Xiaofang
Edraki, Mansour
Baumgartl, Thomas
Kirsch, Bernie
Title Geochemical assessments and classification of coal mine spoils for better understanding of potential salinity issues at closure
Journal name Environmental Science Processes and Impacts   Check publisher's open access policy
ISSN 2050-7887
Publication date 2013-06-01
Sub-type Article (original research)
DOI 10.1039/C3EM30672K
Open Access Status Not Open Access
Volume 15
Issue 6
Start page 1235
End page 1244
Total pages 10
Place of publication Cambridge, United Kingdom
Publisher Royal Society of Chemistry
Collection year 2014
Language eng
Formatted abstract
Coal mining wastes in the form of spoils, rejects and tailings deposited on a mine lease can cause various environmental issues including contamination by toxic metals, acid mine drainage and salinity. Dissolution of salt from saline mine spoil, in particular, during rainfall events may result in local or regional dispersion of salts through leaching or in the accumulation of dissolved salts in soil pore water and inhibition of plant growth. The salinity in coal mine environments is from the geogenic salt accumulations and weathering of spoils upon surface exposure. The salts are mainly sulfates and chlorides of calcium, magnesium and sodium. The objective of the research is to investigate and assess the source and mobility of salts and trace elements in various spoil types, thereby predicting the leaching behavior of the salts and trace elements from spoils which have similar geochemical properties. X-ray diffraction analysis, total digestion, sequential extraction and column experiments were conducted to achieve the objectives. Sodium and chloride concentrations best represented salinity of the spoils, which might originate from halite. Electrical conductivity, sodium and chloride concentrations in the leachate decreased sharply with increasing leaching cycles. Leaching of trace elements was not significant in the studied area. Geochemical classification of spoil/waste defined for rehabilitation purposes was useful to predict potential salinity, which corresponded with the classification from cluster analysis based on leaching data of major elements. Certain spoil groups showed high potential salinity by releasing high sodium and chloride concentrations. Therefore, the leaching characteristics of sites having saline susceptible spoils require monitoring, and suitable remediation technologies have to be applied.

Environmental impact: This work showed that geological classification well represented spoil groups that have potential salinity issues. In this way, salinity can be easily predicted without measuring EC or element concentrations. Cluster analysis of spoils based on leaching characteristics is the first attempt to classify spoils having high salinity potential. Monitoring of salinity from spoil will help to understand water dynamics on the spoil deposition and plan for spoil management.
Keyword Soil hydraulic conductivity
Carbonate minerals
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Centre for Mined Land Rehabilitation Publications
Official 2014 Collection
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Citation counts: TR Web of Science Citation Count  Cited 4 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 5 times in Scopus Article | Citations
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Created: Tue, 04 Jun 2013, 10:37:07 EST by Thomas Baumgartl on behalf of Centre For Mined Land Rehabilitation