The effect of parameters including adding amount (650 〜950 kg) of desulfiirizer (/% ： 80. 55CaO

0. 04S

0. 01P

4. 34SiO

2

6. 06CaF

2

0. 05H

2

O)

stirring time (7 ~ 11 min)

stirring impeller rotating speed (90 〜110 r/min) and submerged depth of impeller (850 ~ 1 150 mm) on efficiency of KR desulphurization of 115 ~ 117 t hot metal (0. 03% ~ 0. 06% S

1 250 〜1 350 ℃ ) has been statistic-analyzed and studied by using response surface method ( RSM)

and a equation of regression model is obtained. Results show that with using the optimized parameters- adding amount of desulfurizer 820 kg

stirring for 9 min

rotating speed of stirring impeller 101 r/min and submerged depth of impeller in bath 985 mm

with hot me

tal KR desulphurization the predicted value of efficiency of desulphurization is 91. 99%

while the real measured value is 90. 18%

the relative error is 2. 0% ； with optimized desulphurization process the consumption of used desulfurizer decreases and the first qualified rate of metal increases from original 88. 35% to 95. 88%.