Abstract
An investigation was made to clarify the basic feature of deoxidation of liquid iron with calcium. In the experiment, calcium metal was added to the bottom part of liquid iron using a silica tube which was inserted into the liquid iron.
The addition of calcium metal in this way gave the high concentration of calcium in the melt and the rapid decrease of oxygen concentration.
The results obtained are as follows:
(1) The concentration of calcium dissolved in the liquid iron is estimated to be at least 0.0103 weight percent at the temperature of 1600°C and in the atmosphere of 1 atm.
(2) The reaction Ca+O=CaO proceeds immediately after the addition of calcium and calcium has been proved to be a very powerful deoxidizer having K′ca= [%Ca][%O] at 1600°C.
(3) When a small amount of calcium is added to the liquid iron in which primary deoxidation products such as SiO2 or Al2O3 are suspended, the concentration of oxygen decreases very rapidly to the equilibrium value calculated from the concentration of deoxidizer.
