Effect of Stirring Intensity on the Metallurgical Reactions in Top-and Bottom-Blowing Processes

The role of stirring intensity in the basic oxygen steel-making process has been investigated in a 5t converter equipped with a top blowing lance and tuyeres for bottom-blowing. Examined blowing patterns were two types of combined blowing in addition to complete top- or bottom-blowing. Examined blowing patterns were two types of combined blowing in addition to complete top- or bottom-blowing. The time required for perfect mixing of steel bath measured by a copper tracer technique was remarkably reduced by introducing bottom-blowing gas, as predicted from a cold model experiment.
The metallurgical characteristics varying with change in stirring intensity observed in the hot model experiment has been discussed and interepreted in terms of a process parameter, ISCO (Index for selective Carbon Oxidation), which consists of the partial pressure of CO gas and the ratio of the flow rate of oxygen to that of liquid steel.