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SUMMARYNumerical study with detailed chemistry has been conducted to investigate the e!ect of CO addition on #ame structure and NO V formation in CH }air counter#ow di!usion #ame. Radiation e!ect is found to be dominant especially at low strain rates. The addition of CO makes radiation e!ect more remarkable even at high-strain rates. It is, as a result, seen that #ame structure is determined by the competition between the radiation and strain rate e!ects. The important role of CO addition is addressed to thermal and chemical reaction e!ects, which can be precisely speci"ed through the introduction of an imaginary species. Thermal e!ect contributes to the changes in #ame structure and NO formation mainly, but the e!ect of chemical reaction cannot be neglected. It is noted that #ame structure is changed considerably due to the addition of CO , in such a manner, that the path of methane oxidation prefers to take CH PCH PC H PC H instead of CH PCH PCH PCH.

The correlation of the equilibrium behaviors of phosphorus and vanadium between slag and low carbon molten steel in inert atmosphere was investigated with respect to the experimental variables of slag basicity, the (P 2 O 5 ) and (V 2 O 5 ) content, and the reaction temperature. The distribution ratios of phosphorus and vanadium increased with an increase in the slag basicity. The logarithms of the vanadium distribution ratio were greater by a factor of about two than those of phosphorus in the range of low slag basicity, but the difference diminished with an increase in the slag basicity. The logarithms of the vanadium distribution ratio increased linearly with an increase in the (P2O5) and (V2O5) content in the slag, while those of phosphorus remained nearly constant. The logarithms of the phosphorus and vanadium distribution ratio decreased with an increase in temperature, and the dependence on temperature was greater for the phosphorus than for the vanadium. For both the maximization of the vanadium yield and the minimization of the rephosphorization of molten steel in the steelmaking process, the ratio of N(V2O5)/N(P2O5), the slag basicity, the ratio of f[P]/f [V], and the temperature should be maximized, and the (FeO) content in the slag should be minimized.

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