| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1992: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1991: ¥1,100,000 (Direct Cost: ¥1,100,000)
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| Research Abstract |
The purpose of present study is to investigate the thermodynamic properties of BaO- MnO fluxes.
The activity of MnO in the BaO-MnO flux was measured at 1573 and 1673K, by equilibrating the flux, a Ag-Mn alloy in a nickel crucible, and a gas mixture of CO and CO_2. The activity of BaO in the flux was calculated by using Gibbs-Duhem relationship. The influence of BaF_2 on the thermodynamics of the BaO-MnO system, including the solubility of MnO in the BaO-BaF_2 system, was also investigated at 1573K and the liquid region was established in the BaO-BaF_2-MnO ternary diagram..
Furthermore, the phosphorus and manganese partition ratios between BaO-MnO(BaF_2,CaO) melts and carbon saturated Fe-Mn melts were measured between 1573 and 1673K in a CO atmosphere. The sulfur partition ratio between BaO-MnO flux and silver was also measured at 1573K with the partial pressure of oxygen of 7.03X10^<-5>Pa. The phosphorus partition ratio increases with increasing BaO content of the flux. The manganese partition ratios were approximately constant at 0.64, 0.33 and 0.23 at 1573, 1623 and 1673K, respectively. The phosphate capacity of the BaO-MnO flux is as high as that of BaO-MnO flux and is far larger than those of CaO-bearing fluxes. The sulfide capacity of the BaO-MnO system at 1573K increases with increasing BaO content of the flux. Its value ranges from 10^<-0.4> to 10^<-0.2> and is far larger than any known flux systems.
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