Prediction of Metal Mobility from Sulfidic Waste Rocks Using Micro-analytical Tools, Baal Gammon, Northern Australia
Predictions on the behavior of environmentally significant elements at mine sites requires the use of advanced laboratory techniques. The aim of this contribution is to demonstrate the use of electron microprobe analysis (EMPA) and laser ablation inductiv
- PDF / 1,143,563 Bytes
- 20 Pages / 439.37 x 666.142 pts Page_size
- 17 Downloads / 163 Views
Abstract Predictions on the behavior of environmentally significant elements at mine sites requires the use of advanced laboratory techniques. The aim of this contribution is to demonstrate the use of electron microprobe analysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to gain an understanding of likely element behaviour. Sulfidic boulders sampled from an acid rock drainage (ARD) impacted ephemeral stream adjacent to the historical Baal Gammon workings are dominated by chalcopyrite, arsenopyrite, pyrrhotite and lesser pyrite. Micro-analytical investigations using EMPA and LA-ICPMS reveal that chalcopyrite contains significant quantities of Ag, Cd, Sn, In and Zn either substituted directly into the crystal lattice or occurring as discrete sphalerite and stannite inclusions. Arsenopyrite, comprising more than 50 % of some boulders, is most notably rich in Co, Ni, Sb and Se, but it also contains inclusions of sphalerite, chalcopyrite and stannite. By contrast, pyrrhotite contains relatively few trace elements, but it may be a significant contributor to ARD development. The trace element composition of Fe-oxides in the oxidized rinds of these boulders is likely directly influenced by the mineralogy of the sulfidic boulders on which they precipitate. Although significant quantities of As, Bi, Cu, In, Pb and Zn occur in Fe-oxides at Baal Gammon, these elements may be liberated during acid flushing of the ephemeral stream. Consequently, EMPA and LA-ICPMS represent valuable tools for evaluating the source and potential mobility of environmentally significant elements at mine sites.
N. Fox (&) A. Parbhakar-Fox School of Physical Sciences, University of Tasmania, Hobart, TAS 7001, Australia e-mail: [email protected] A. Parbhakar-Fox e-mail: [email protected] B. Lottermoser Institute of Mineral Resources Engineering, RWTH Aachen University, Wüllnerstrasse 2, 52062 Aachen, Germany e-mail: [email protected] © Springer International Publishing Switzerland 2017 B. Lottermoser (ed.), Environmental Indicators in Metal Mining, DOI 10.1007/978-3-319-42731-7_14
243
244
N. Fox et al.
Introduction The Herberton tin-tungsten province in north Queensland, Australia (Fig. 1) has been a significant contributor to Australia’s total tin production since the 1880s (Blake 1972). At least 2000 historical lode and alluvial mines and workings occur in the province, yielding over 150 kt of tin and 4 kt of tungsten (Solomon and Groves 1994). Tin mineralization largely occurs in greisen, skarn and breccias associated with Late Carboniferous granites forming polymetallic deposits that contain cassiterite, wolframite, chalcopyrite, sphalerite and galena with gangue arsenopyrite, pyrrhotite and pyrite. The rising global demand for tin and critical metals, particularly indium and tantalum (Skirrow et al. 2013), has driven a resurgence in mining and exploration in and around historical tin-tungsten provinces including the Herberton province, Queensland. Baal Gammon, located 7 km west of H
Data Loading...
