According to issue of increasing cost and decreasing liquid quality by BOF recarburization process to melt medium and high carbon steel using semi-steel at Pan Gang

the chemical thermal compensating process by increasing silicon content of semi-steel is adopted

and based on dephosphorization thermodynamics in BOF and enrichment regularity of phosphor in slag

it is obtaind that enrichment phase of phosphor in slag is 2CaO • SiO

2

. By using technologic measures such as fast slagging

reduce tapping temperature

it is obtained that the enrichment phase of phosphor in slag is increased

which improve the dephosphorization effect. Results of test indicate that the new thermal compensating process improves the thermal resource of semi-steel as well as shorten the slag forming time from 4. 1 min to 2. 5 min

and the average carbon content of steel at endpoint is of BOF 0.18%

it is obt

aind that temperature is 1653 °C

TFe content of slag is average reduced by 2. 81 percent point

phosphor content of steel is all less than 0.015% .