Effect of Stirring Force by Bottom Blown Gas and Partial Pressure of CO in It on Characteristics of Metallurgical Reaction in a Converter

Synopsis : Experiments were carried out in 5 t converter using five kinds of gases as a bottom blown gas in order to quantitatively evaluate the contributions of stirring force and dilution of Pco by bottom blown gas to characteristics of metallurgical reactions in a converter. On the basis of the experimental results, a new reaction model was proposed, which enables us to reasonablly explain the metallurgical reactions in a converter with bottom blown gases. The results obtained are summarized as follows ; 1) Independently of sort of bottom blown gas, oxygen concentration dissolved in steel decreases as increasing the gas flow rate of bottom blown gas. 2) Taking into consideration oxygen transfer from metal to slag, the model can reasonablly explain the phenomena that concentrations of carbon and oxygen reduce to those in equilibrium with less than 1 .0 atm of CO. 3) The amount of oxygen transfer from metal to slag increases with increasing the stirring force by bottom blown gas and decreasing carbon concentration in molten steel. 4) The effect of dilution of Pco on behavior of oxygen concentration in steel and (%T. Fe) in slag is considered to be small. Hence, the decreases of. oxygen and (%T. Fe) in IOD(Inert and Oxygen Gases Decarburization) mode result from the increase of stirring intensity by inert gas blown from bottom.