Slag and the corresponding hot metal samples were collected just before tapping from electric arc furnace of Ezz Flat Steel Company (EFS) and analyzed. The temperature of hot metal was measured before tapping.
The analyses of slag and hot metal together with the metal temperature were used to estimate the activity coefficient and activity of total ferrous oxides in slag, also investigate carbon and oxygen activity coefficient in steel according to the statistical theory of regular ionic solutions.
The oxides capacity of the slag was also assessed. The variation of carbon and oxygen activity in hot metal with the concentration was also treated.
The ratio of activity to concentration of total ferrous oxides is constant and equal to 0.0179. The activity coefficients of oxygen and carbon in steel are 0.810 and 1.0704, respectively.
The oxides capacity of the slag increases with increasing carbon concentration in the bath and with increasing DRI proportion in the charge.