The pressure dissolution behaviour of pyrite was investigated via its polarisation curve and using electrochemical impedance spectroscopy (EIS) in a FeCl3 solution under differential stress. The results showed that the pyrite pressure dissolution process is a galvanic corrosion process and that there is a negative linear relationship between the pyrite potential difference and the stress action. The EIS experiments confirm that the pyrite was in a passive state in a 0.0010 mol L-1 FeCl3 solution and that a thin surface layer of Fe1-yS2 was present. In a 0.010 mol L-1 FeCl3 solution, the pyrite was in a trans-passive state, in which the aforementioned passive layer became porous. In a 0.10 mol L-1 FeCl3 solution, the pyrite was in an active state, the surface layer dissolved completely, and a lattice layer of S-2(0) was created instead of a passive layer of S-0. Under the present stress conditions, the stress action did not change the pyrite electrochemical dissolution mechanism; however, the conditions decreased the charge transfer resistance and passive resistance and increased the species diffusion capacitance. (c) 2012 Elsevier Ltd. All rights reserved.
Publication name |
APPLIED GEOCHEMISTRY Volume: 29 Pages: 144-150 Published:FEB 2013 |
Author(s) |
Liu, Qingyou; Zhang, Yanqing; Li, Heping
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Corresponding author |
LIU Qingyou
liheping123@yahoo.com
Chinese Acad Sci, Inst Geochem, Lab High Temp & High Pressure Study Earths Interi, Guiyang 550002, Peoples R China.
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