The influence of bath agitation intensity on metallurgical characteristics in top and bottom blown converter was studied by using 70 ton LD converter and the following main benefits in metallurgical reaction were obtained in comparison with LD converter.
1) In this process, iron oxide in slag and the oxygen content, under the same carbon content at turn down, become lower than in LD process.
2) The aimmed dephosphorization reaction is attainable in spite of lower iron oxide in slag.
3) The manganese content at turn down rises.
4) The controllable range of iron oxide can be more extended by selecting the relative intensity of the top-and bottom blowing conditions, than by LD or Q-BOP process.
It has been shown that the content of iron oxide in slag is controlled by the newly defined operational index of BOG, which means the balance of the formation rate of iron oxide and the feeding rate of carbon as a reducing agent determined by the time required for fully mixing and carbon content.
Balance of Oxygen-and Carbon-feeding rate= QO2S/(W/τ)[%C]
