Revised pourbaix diagrams for zinc at 25–300 °C
1997; Elsevier BV; Volume: 39; Issue: 1 Linguagem: Inglês
10.1016/s0010-938x(97)89246-3
ISSN1879-0496
AutoresB. Beverskog, I. Puigdomènech,
Tópico(s)Thermal and Kinetic Analysis
ResumoPourbaix diagrams (potential/pH diagrams) for zinc at 25–300°C have been revised. The diagrams were calculated for three concentrations, 10−5, 10−6 and 10−8molal, the latter for use in high purity water such as in nuclear power reactors. Extrapolation of thermochemical data to elevated temperatures has been performed with the revised model of Helgeson-Kirkham-Flowers, which also allows uncharged aqueous complexes, such as Zn(OH)2(aq), to be handled. The calculations show that the hydroxide of zinc does not passivate at the concentration of 10−6M, due to the uncharged zinc(II) complex, Zn(OH)2(aq). However, at concentrations ≥ 10−5.7 M zinc passivates by formation of ZnO, which is stable in the temperature interval investigated.
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