The tested hot metal containing 0.40% P is made from commercial iron

phosphoric iron and ferrous sulfide with slagging forming material lime : fluorite =9 ：1 and slagging forming material : metal = 1 ：50

and melted at 1600℃. by a tube-type electric resistance furnace. The effect of the microstructure of lime-specific surface area (1.05~4.75 m

2

/ g)

average pore diameter (605~ 404 nm)

pore volume (0.23~0.78 mL/g) and bulk density (0.80~3.10 g/cm

3

)

and the activity of lime (298~350 mL) on dephosphorization of hot metal has been studied by field emission SEM and automatic pressure mercury device. Results show that with increasing the activity of lime the dephosphorization ratio increases gradually ； with increasing the specific surface area

average pore diameter

pore volume and bulk density

the dephosphorization ratio of metal increases first and then decreases ； with lime specific surface area 2.5 m

2

/g

average pore diameter 750~850 nm

pore volume 0.45 ~0.55 mL/g and bulk density 2.0 g/cm

3

the dephosphorization ratio of metal is highest

it is up to 63.0%.