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HERO ID
6575106
Reference Type
Journal Article
Title
Curing temperature dependency of the release of arsenic from cemented paste backfill made with Portland cement
Author(s)
Bull, AJ; Fall, M; ,
Year
2020
Is Peer Reviewed?
Yes
Journal
Journal of Environmental Management
ISSN:
0301-4797
EISSN:
1095-8630
Volume
269
Page Numbers
110772
Language
English
PMID
32560993
DOI
10.1016/j.jenvman.2020.110772
Web of Science Id
WOS:000541757200014
Abstract
In this research, the effect of curing temperature on the metalloid (As) leachability of cemented paste backfill (CPB; a mix of tailings, cement and water) is studied. ASTM C 1308 leaching protocol is used to determine the leachability of CPB samples subjected to different curing temperatures (2, 20 and 35 °C). In addition, the effect of curing temperature on the microstructure of CPB is assessed to determine if the temperature dependence of the leaching characteristics of CPB is related to variations in the microstructure of the cement matrix. The microstructural techniques used include, powder x-ray diffraction, mercury intrusion porosimetry, and scanning electron microscopy techniques. The results obtained indicate that the curing temperature has a significant effect on the leachability of CPB. It is found that as curing temperature increased from 2 °C to 35 °C the performance of the CPB for arsenic immobilization decreased. The magnitude of this temperature-induced change in As-leachability of CPB depends on the curing temperature range (low (≤20 °C) or elevated (35 °C) temperatures). This curing temperature dependency of the leachability of CPB is attributable to the temperature-induced changes in the pore structure of CPB, formation/development of hydration products and pH in the CPBs during the curing process. The results also indicate that diffusion dominates as the leaching mechanism through the studied temperature range and is independent of curing temperature. However, curing temperature does control the availability for arsenic to leach. The new findings presented in this paper will contribute to design more environmental-friendly cemented paste backfill materials and structures, which is vital for sustainable mining.
Keywords
Cemented paste backfill; Tailing; Arsenic; Leaching; Cement; Mine
Tags
IRIS
•
Arsenic Hazard ID
Lit Search Updates Jan 2019 to April 2021 (OPP)
New to this search
PubMed
WOS
Lit Search Updates Jan 2019 to August 2022
PubMed
•
Inorganic Mercury Salts (2)
Mercuric Sulfide
Litsearch 2019-2020
PubMed
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