the desulphurizing refining time for average sulphur content in steel from 0.060% to 0.015% decreased to 20~30 min from original 30~45 min by adding lime 400~450 kg and synthetic slag 80~250kg
controlling EAF tapping steel temperature 1580~1630℃
increasing refining slag amount
ensuring refining slag basicity 1.5~2.8
Ar stirring rate 180~280 L/min and average(TFe)≤1.0%.