铁水复合喷吹脱硫生产低硫钢的实践

结合复合喷吹脱硫的工艺特点,分析确定转炉出钢回硫的原因主要受铁水及脱硫渣、原材料带入硫的影响。通过控制原材料硫含量,提高品位,选择合适的喷吹速度、合理控制脱硫剂配比,合理控制喷吹罐压力及助吹气体压力,调整喷枪插入铁水液面的深度,对脱硫扒渣工艺进行优化;调整扒渣板的角度和透气砖的安装高度,对扒渣设备进行攻关。对脱硫工艺条件和转炉冶炼进行规范,通过全工序控制的方法,有效控制转炉钢液回硫的现象,实现了低硫出钢的目标,转炉钢液回硫质量分数控制在25×10-6以内,出钢w(S)稳定在40×10-6以内。

Production of low sulfur steel by hot metal desulfurization with compound injection

In view of the characteristics of the compound injection desulfurization technology the origin of the sulfur pick-up during the tapping of converter is analyzed and finally determined that the primary cause to the phenomenon is carry-over of sulfur into the molten steel from the hot metal,desulfurization slag and other raw materials.By means of implementation of a series technological measures such as strictly controlling the sulfur content of the raw materials,raising the grade of the starting materials,properly selecting the spray rate,rationally controlling the ratio of desulfurizers,the pressure of the injection pot and pressure of the auxiliary blowing gas,appropriately readjusting immersion depth of spraying gun into the hot metal,optimizing the deslagging process,adjusting the angle of the deslagging board as well as the installation height of the porous fire bricks,standardizing the technological conditions of desulfurization and converter refining and initiating an overall process control the phenomenon of sulfur pick-up can be effectively controlled and the target of tapping low sulfur steel can be realized.In the end the quality fraction of sulfur pick-up of the converter is controlled in the range of 25×10-6,and the tapping sulfur content is steadily controlled in less than 40×10-6.