Based on research of refining slag series by 55~75kg experimental ladle furnace (LF)

the commercial production experiment of embedding are refining slag in a 60t ladle furnace has been carried out using three kind of slag:S1  slag-63.6~70.0 lime

22.7～25.0 high alumina and 5.0~13.6 fluorite; S2 slag-60.0~66.7 lime

20.8～25.0 fluorite and 12.5～15.0 refractory block; and S3 slag-55.5～65.0 lime and 35.0～44.5 fluorite

and the refining steel grades were 20

20G

40Cr

35CrMoA and CCr15  steel. The results showed that all average desulphurization rate of molten steel using the three-slag series was 87%

and the average heat up rate of molten steel during LF refining was 3.84 ℃/min

2.86 ℃/min and 2.48 ℃/min respectively by using S1

S2 and S3 slag series. As desulphurization speed was quick by using S1 slag therefore the refining time decreased.