Thermodynamic Investigation of the BaO - B2O3 Slag at High Temperature
민동준 Dong Joon Min
Abstract
Present study was carried out to understand the thermodynamic behavior of BaO-B₂O₃ slag system at high temperature by chemical equilibration technique. Also, thermodynamic properties of Ag-Ba binary system at high temperature was measured to carry out the above mentioned investigation by the same technique. Thermodynamic behavior of Ba in Ag melts shows negaive deviation from ideal solution and can be expressed quantitatively by using α function concept as follows : logγ_(Ra)=2.63(1-X_(Ba))² α=logγ_(Ba)/(1-X_(Ba))²=2.3-7700/T BaO activity was increased with increasing the mole fraction of BaO and shows the negative deviation from the ideal sloution model. Thermodynamic properties of BaO shows similar behavior with CaO system. The thermodynamic properties of BaO in BaO-B₂O₃ slag system could be related with the stability of BaO-B₂O₃ melts which was considered to be stable compound at high temperature as a 3BaO·B₂O₃ composition. also, comparison between BaO and CaO activity and optical basicity was carried out to confirm relative strength of BaO basicity to CaO. BaO system shows higher optical basicity than CaO system at the same activity of those basic oxide, This fact may imply that BaO was more effective oxide for the refining reagents because of strong basicity.