CaO-CaF₂-SiO₂フラックスの炭酸ガス溶解度

抄録

The solubility of carbon dioxide has been measured by the thermogravimetric technique for CaO-CaF₂-SiO₂ molten fluxes at temperatures from 1 200 to 1 500°C. The values of carbonate capacity (C_C=wt%CO₃^2-/P_CO2) were calculated by the solubilities and the partial pressure of carbon dioxide.
Carbonate capacities were compared with the sulfide capacities appearing in the literature. A linear relationship was obtained for C_S^2- and C_C as log C_S^2-=1.1 log C_C -3.3 at 1 200 °C.
With increasing CaF₂ from 29.0 to 88.2wt% at constant X_CaO/X_SiO2 of three at 1 400°C, C_C increased from 0.53 to 0.89.
The influence of the replacement of CaO by CaF₂ on C_C at various SiO₂ content has been investigated. With increasing CaF₂, C_C decreased for fluxes of X_CaO/X_SiO2 smaller than three, while it increased for fluxes with a ratio larger than three.
Carbonate capacities of slags of X_CaO/X_CaF2=1.56 decreased with increasing SiO₂ content from 8.3 to 25wt%. In fluxes of which the ratio was 0.68, C_C decreased with an increase of SiO₂ more than 5wt%. There was a maximum of C_C at 0.8wt%SiO₂ for the fluxes of a ratio of 0.14.