
%0 Journal Article
%A Pound, BG 
%A Wright, GA 
%A Sharp, RM 
%T Electrochemical Phase Diagrams for the Fe/S/H<sub>2</sub>O System under Geothermal Conditions
%J Australian Journal of Chemistry
%D 1985/05/01
%V 38
%N 5
%P 643-657
%K 
%R https://doi.org/10.1071/CH9850643
%U https://www.publish.csiro.au/paper/CH9850643 
%X Previously published electrochemical phase (potential-pH) diagrams for the Fe/S/H2O system at elevated temperatures are assessed. It is concluded that the potential-pH equations derived by Biernat and Robins1 can be used to provide reliable diagrams over the temperature range 298-573 K. These equations were used to derive a set of diagrams relevant to geothermal fluids in general terms, so that the corrosion products of iron and ferrous alloys immersed in these fluids may be predicted. In addition, diagrams are presented for geothermal fluids in the Broadlands and Wairakei fields in New Zealand. The significant changes in the E-pH diagrams as the temperature increases over the range 298-573 K are that the region of stability for Fe(OH)3- widens and the regions of stability for FeS2 and Fe3O4 and, at higher temperatures, FeS, shrink in size. 
