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Thermodynamic behaviour of carbon in CaO‐SiO 2 slag system
Author(s) -
Song HyoSoek,
Rhee ChangHee,
Min DongJoon
Publication year - 1999
Publication title -
steel research
Language(s) - English
Resource type - Journals
eISSN - 1869-344X
pISSN - 0177-4832
DOI - 10.1002/srin.199905608
Subject(s) - slag (welding) , solubility , dissolution , carbide , chemistry , carbon fibers , metallurgy , steelmaking , inorganic chemistry , oxygen , materials science , chemical engineering , composite material , organic chemistry , engineering , composite number
In order to understand the thermodynamic behaviour of carbon in steelmaking slag at high temperature, the carbon dissolution into CaO‐SiO 2 slag system has been investigated including the effects of temperature and slag components on the carbon dissolution reaction. It was found that carbide solubility in the CaO‐SiO 2 slag decreased with increasing oxygen potential to confirm the theoretical relationship of −1/2, which reflected the ionic exchange reaction mechanism between carbon and oxygen ions. Carbide solubility in slag as a function of slag basicity for various slag systems appeared to confirm this mechanism. This reaction mechanism implied that the carbide dissolution proceeded due to the reaction of solid carbon and oxygen ions supplied from (CaO) in slag. The oxygen ion appears to be the driving force as it is influenced by the slag components as well as the temperature as shown in the concept of the carbide capacity of slag. The solubility of carbide in the CaO‐SiO 2 slag increased with the addition of CaF 2 ; the role of CaF 2 for carbide dissolution into slag could be speculated to have complex effects on indirect increase in basicity in spite of (CaO) dilution. Substitution of CaO by MgO decreased the solubility of carbide in the CaO‐SiO 2 ‐MgO slag, possibly caused by the relatively low electro‐negativity of MgO.