Nitrogen solubility in molten CaO-SiO2 slags

The equilibrium nitrogen solubility in the CaO-SiO2 system was studied by a slag-gas equilibration technique, in graphite crucibles at 1823K under a C O-N-2 atmosphere. The nitrogen content of the slags was determined by the K jeldahl method. A reliable technique was used to obtain an initial nitrogen content in the master slags, from the addition and pre-melting of silicon nitride. Reduction of silica by graphite was found to occur during the equi libration experiments, resulting in compositional changes of the slags. The results were extrapolated to equilibrium by kinetic evaluation of the data . The nitrogen solubility showed good agreement with the result of Suite an d Sane, while Fruehan's results were lower. However, the results of the pre sent study do not support the maximum nitrogen solubility values found by S ane.