As the cleanliness steel was melted by 120 t converter at Masteel

with using ≤ 0.002% S deep-desulphurizing hot metal

cold charge ratio 17%

using[S

]

≤0.020% low sulphur quality scrap steel

applying off gas analysis dynamic-state controlling technique

controlling converter end slag basicity 3.2～3.5 and adding active lime 600 kg

during tapping

it ensured the end [S

]

≤ 0.008%

the percentage of hits for end [C

]

and temperature increased

the end active oxygen content in steel was 556×10

-6

the blowing melting lose and splashing decreased

the lime etc slag-making material was ≤ 90 kg/t and the charge of iron and steel was ≤ 1104 kg/t.