A New Expression of Slag Basicity and its Application to Several Iron and Steel Making Reactions

Abstract

In order to extend the new definition of basicity, which the author has recenly proposed taking the well-known fact that the ferrous and ferric concentrations in a slag change regularly with the basicity, to any generalized slag system, the following expression of slag basicity was given. B_L=∑\limits_ia_iN_i (N_i-mol fraction of the constituent, a_i-constant characteristic of the constituent). The values of the constants a_i are shown in Table 1. Several applications of this new expression of slag basicity were illustrated, and the significances of basicity in the iron and steel making reactions was clarified. The applied examples are as follows: (1) Solubility of magnesia in the CaO-SiO₂-FeO-MgO slag. (2) Sulphur capacity of slags. (3) Desulphurizing reaction between blast furnace slags and metal. (4) Partition equilibrium of sulphur between basic slags and metals. (5) Reduction of titanium and silicon from slags containing titanium-oxide. (6) Desulphurizing power of slags containing titanium-oxide. (7) Reduction of silicon from flux into deposited metal in welding.