Gilbert.Cooke.Hollings.ENVIROGEO.2003.pdf (444.41 kB)
The effects of hardpan layers on the water chemistry from the leaching of pyrrhotite-rich tailings material
journal contribution
posted on 2023-05-16, 14:36 authored by Gilbert, SE, David CookeDavid Cooke, Hollings, PColumn leaching experiments were used to determine the effects of an iron-rich hardpan layer, on the rate of tailings oxidation and the composition of leachate waters, from the Renison Bell tailings dams in western Tasmania, Australia. One-meter-long PVC columns, filled with tailings, cover material (Cassiterite Flotation Tailings) and hardpan samples from the tailings dams, were leached over a period of 14 weeks. Under dry cover conditions, when hardpan was present, the solute loads peaked at 21-49 days (Fe at 2,294 ppm and SO4 2- at 4,700 ppm), and stabilised at much lower concentrations after 9 weeks. In contrast, the solute loads steadily increased over time in the column where hardpan was absent (SO4 2- from 1,800 to 3,100 ppm, and Fe from 407 to 1,692 ppm). Under saturated cover conditions, the solute concentrations in the leachate also increased with time (SO4 2- from 1,900 to 17,000 ppm, and Fe from 480 to 8,500 ppm). The presence of a hardpan layer between the reactive tailings and cover material has been found to improve leachate water chemistry and lessen the rate of sulphide oxidation.
History
Publication title
Environmental GeologyVolume
44Issue
6Pagination
687-697ISSN
0943-0105Department/School
School of Natural SciencesPublisher
Springer-VerlagPlace of publication
Heidelberg, GermanyRepository Status
- Restricted