Abstract: Converter dephosphorization in Beiying steelmaking plant of Benxi steel group corporation, depended on high basicity, large quantity of slag, high oxidization, low temperature technology in the past. More emphasis on the amount of lime caused high lime consumption, being 40－50 kg/t, and ignoring the slag fluidity and thermodynamic conditions. The plant began to study slag-forming process in 120 t converter in 2016, by reducing slag melting point, changing its liquidity, and improving dynamic conditions. Lime consumption of converter reduced from 42 kg/t to 33 kg/t, decreased by 1/5. And the dephosphorization rate of molten steel in converter endpoint increased form 87 % to 92 %.A large number of production practices show that the converter less slag smelting process was feasible.

Key words: converter, less slag smelting, remaining slag, dephosphorization rate, lime consumption