The average silicon content of the hot metal produced by Corex furnace is 0.6-1.5 mass%, which increases the oxygen blowing time and leads the unsatisfactory dephosphorization, high reblowing rate. ...The oxidation of carbon and silicon and optimization of dephosphorization during the refining process were studied through industrial practice and theoretical calculation. The results show that the optimum residual content of silicon in liquid steel at first slag making phase is about 0.05-0.07 mass%. The phosphorus content of liquid steel at first deslagging can be controlled at a low level (0.055-0.060 mass %), when the temperature is 1340-1360°C. The slag basicity of first deslagging should be controlled about 1.5, and (FeO) content should be controlled within 15%. In order to control the P of molten steel within 0.01mass%, the basicity should be higher than 3.4 and the temperature should be less than 1640°C.
This study focuses on understanding the dephosphorization behaviors in converter steelmaking process under different situations. When controlling the basicity of slag, Fe
t
O content and bath ...temperature by single slag and double slag-slag remaining operation to blow ordinary P-containing hot metal, the equilibrium value of phosphorus (P
e
) between hot metal and slag in the early stage of steelmaking is lower than 0.0068%, and the ratio of actual phosphorus content (P
r
) to equilibrium value (Pe) is less than 4.6. By using top-blown lime powde, dephosphorization efficiency of high phosphorus hot metal at the early stage was up to 93.8%, and P
r
/P
e
lowered to be 2.24. When lime slagging instead of the top-blown lime powder method was used, the dephosphorization effect is bad in the early stage of blowing the medium phosphorus hot metal by double slag process, and it leads to high material consumption and low productivity.
