University Of Tasmania
152600 - Unexpected non-acid drainage from sulfidic rock waste.pdf (2.75 MB)
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Unexpected non-acid drainage from sulfidic rock waste

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journal contribution
posted on 2023-05-21, 12:27 authored by Gerson, AR, Rolley, PJ, Davis, C, Sandrin FeigSandrin Feig, Doyle, S, Smart, RSC
Most rock extraction sites, including mine sites and building construction sites, require a plan to assess, and mitigate if present, the risk of acid mine drainage (AMD). AMD is typically the major environmental concern where sulfide minerals are present in the excavated material and AMD prediction and remediation is based on internationally-accepted acid-base accounting (ABA) tests of representative field samples. This paper demonstrates that standardized ABA tests may not always be provide the correct AMD classification for commonly occurring waste rocks containing low-pyrite and -carbonate due to mineralogic assumptions inherent in their design. The application of these standard ABA tests at a copper mine site in South Australia resulted in the classification of a portion of its waste material as potentially acid forming in apparent contradiction to long term field measurements. Full definition of the sulfide and silicate minerals enabled re-evaluation of the weathering reactions occurring. The overall rate of neutralisation due to silicate dissolution was found to always exceed the rate of acid generation, in agreement with field observations. Consequently, the waste rock was redefined as non-acid forming. The methods developed represent a significant advance in AMD prediction and more strategic, cost-effective environmental planning, with potential for reclassification of wastes with similar characteristics.


Publication title

Scientific Reports



Article number









Nature Publishing Group

Place of publication

United Kingdom

Rights statement

Copyright 2019 the authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0)

Repository Status

  • Open

Socio-economic Objectives

Other environmental management not elsewhere classified