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
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.

View here for the details from the publisher