Kinetics studies on the dissolution of nitrogen in the CaO-Al2O3-SiO2 and CaO-Al2O3-TiO x melts

The rate of nitrogen dissolution in CaO-Al₂O₃-SiO₂ and CaO-Al₂O₃-TiO _x melts was measured by ¹⁴N–¹⁵N isotope exchange reaction. The rate constant for the CaO-Al₂O₃-SiO₂ melts at the ratio of mass pct CaO/mass pct Al₂O₃ = 1 increases as SiO₂ content increases, whereas the rate constant for the same melts at the ratio of mass pct CaO/mass pct SiO₂ = 1 increases as Al₂O₃ content increases. The rate constant for the CaO-Al₂O₃-TiO _x melts at the ratio of mass pct CaO/mass pct Al₂O₃ = 1 decreases as the TiO _x content increases. The activation energies of nitrogen dissolution in CaO-Al₂O₃-SiO₂ melts are about 1.5 to 3 times larger than that of molten pure iron. Moreover, the rate constant of nitrogen dissolution is independent of the ratio of Ti³⁺/Ti⁴⁺.