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Thermodynamic behaviour of zinc in Fe‐C and CaO‐FeO‐CaF 2 slag at high temperatures
Author(s) -
Moon Seok Min,
Lee Myoung Jin,
Min Dong Joon
Publication year - 2002
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.200200193
Subject(s) - zinc , slag (welding) , dissolution , chemistry , activity coefficient , metallurgy , alloy , stoichiometry , oxygen , steelmaking , inorganic chemistry , nuclear chemistry , materials science , aqueous solution , organic chemistry
The distribution ratio of zinc between Ag‐Zn and Fe‐Zn alloys was measured to clarify the thermodynamic behaviour of zinc in Fe‐C melt at high temperatures. Also, the distribution ratio between Ag‐Zn alloy and CaO‐FeO‐CaF 2 slag was measured to understand the dissolution mechanism of zinc in molten slags. The activity coefficient of zinc in Ag‐Zn alloy was preliminarily measured as a fundamental thermodynamic data for the activity of zinc in Fe‐C melt. From the dependence of the activity coefficient of zinc in Fe‐C melts on temperature and carbon content, the following equation could be obtained at 1473 ‐ 1623 K: ln γ Zn Fe − C = 35.1 − 42200 T + 20.9 ( X C − X C satd ) ( 1573 K ≤ T ≤ 1623 K ) .The distribution ratio of zinc between Ag‐Zn alloy and CaO‐FeO‐CaF 2 slag increased by increasing both the oxygen potential and slag basicity. The stoichiometric coefficients of the dissolution reaction were obtained by considering the relationship between zinc distribution ratio and slag basicity or oxygen partial pressure, when one of these two independent variables was fixed. The dissolution reaction of zinc into the slags could be described as follows: Zn ( 1 ) + 2 O 2 − ( slag ) + 1 2 O 2 ( g ) = ZnO 3 4 − ( slag ) .