Based on real production data

the process for melting low carbon steel 08Al (% : ≤0. 08C

0. 17 - 0. 37Si

0. 25 〜0. 65Mn

≤0. 030P

W0. 030S

0. 015 〜0. 065 Als) by an 100 t top and bottom combined blown converter at Lianyuan Steel has been analyzed and studied. It is found that its bottom blowing is intense in later period led to part liquid over-oxidation

and there is a definite deviation between the real end [C] [O] and the theoretical equilibrium [ C] [O] product; as basicity of converter end slag is 4 ~ 5

the distribution coefficient of phosphorus and sulphur between liquid steel and slag is largest and the effect of dephosphorization and desulphurization is best

while higher end [C]

lower (FeO) and lower oxidability of slag are unfavourable to dephosphorization but favourable to desulphurization； and the lower encl temperature of melting liquid steel

higher [C] and lower oxidability of liquid and furnace slag

the higher the residual manganese content in liquid steel.