According to calculation

for SP etc. low carbon steels the adding scrap ratio to control converter liquid end temperature is no less than 16%

but present scrap supply for 120 t converter is only up to 13%

led to liquid end temperature higher to effect lining life. According to analysis

the end temperature of liquid in converter is adjusted and controlled by adding limestore (/% : ≥53.0CaO

≤1.2SiO

2

≤0.40S

≤0.008P). The production practice with 54 heats show that as adding 500-1000 kg limestone with liquid temperature 1 660-1669 Y

liquid average temperature dropped by 3.6-8.0 ℃

1670-1679 °C

dropped by 4.9-10.8 P

and m 1680 ℃

dropped by 9.0-20.0 ℃ ； by adding limestone the average liquid dephosphorizing ratio is 83%

it is basically about equal to the dephosphorizing ratio (87% ) by adding iron ore.