铁水预处理镁系脱硫渣流动性能调控研究

Study on fluidity control of magnesium desulfurization slag after hot metal pretreatment

镁系脱硫剂与硫的亲和力强,脱硫效率高,是铁水预处理脱硫过程常用的脱硫剂之一,但脱硫后的渣具有渣稀、不易扒渣等特点。为了改善脱硫渣的流动性、增加界面的粘接力、降低扒渣铁损,研究了脱硫渣改性剂碱度和添加量对脱硫渣黏度的影响。首先采用FactSage热力学软件对不同碱度和FeO加入量的脱硫渣黏度进行了模拟计算,分析了碱度和FeO加入量对脱硫渣黏度的影响。然后通过绘制CaO-SiO_(2)-Al_(2)O_(3)-MgO(10%)-FeO(11%)脱硫渣的等温液相线图,找到了脱硫渣扒渣难的原因。利用熔渣综合物性测定仪测定了加入脱硫渣改性剂前后熔渣的黏度。结果表明:未加入脱硫渣改性剂之前脱硫渣的黏度均偏低,达不到合适的扒渣黏度;加入脱硫渣改性剂后可以增大脱硫渣的黏度,适宜的脱硫渣改性剂添加量为脱硫渣改性剂与脱硫渣配比为2∶5、3∶5,此时在扒渣温度区间1330~1340℃,脱硫渣黏度在2.007~2.114、2.5~2.77 Pa·s,有利于脱硫渣的粘结。

Magnesium desulfurizer has strong affinity with sulfur and high desulfurization efficiency.It is one of the commonly used desulfurizers in hot metal pretreatment desulfurization process.However,the desulfurized slag has the characteristics of thin slag and not easy to pick up slag.In order to improve the fluidity of desulfurization slag,increase the adhesive force of interface and reduce the iron loss of slag removal,the effects of basicity and addition amount of desulfurization slag modifier on the viscosity of desulfurization slag were studied in this paper.Firstly,Factsage thermodynamic software was used to simulate the viscosity of desulfurization slag with different basicity and FeO addition,and the influence of basicity and FeO addition on the viscosity of desulfurization slag were analyzed.Then,by drawing the isothermal liquidus diagram of CaO-SiO_(2)-Al_(2)O_(3)-MgO(10%)FeO(11%)desulfurization slag,the reason why it was difficult to remove the slag from the desulfurization slag was found.The viscosity of slag before and after adding desulfurization slag modifier was measured by slag comprehensive physical property tester.The results show that the viscosity of desulfurized slag is low before adding desulfurized slag modifier,and the appropriate viscosity of desulfurized slag cannot be reached.The viscosity of desulfurized slag can be increased by adding desulfurized slag modifier.The appropriate addition amount of desulfurized slag modifier is that the ratio of desulfurized slag modifier to desulfurized slag is 2∶5 and 3∶5.At temperature range of 1330-1340℃,the viscosity of desulfurized slag is 2.007-2.114、2.5-2.77 Pa·s,which is conducive to the bonding of desulfurized slag.