钢中硅质量分数对出钢渣洗脱硫效果影响

 为了提高出钢渣洗脱硫效果，在国内某钢厂300 t转炉进行了21炉出钢渣洗脱硫试验。研究结果表明，当钢中Als和硫质量分数分别为0.025%～0.045%和0.002%～0.004%时，钢中硅质量分数对出钢渣洗脱硫效果影响十分显著，而锰质量分数对出钢渣洗脱硫效果没有直接的影响。通过将出钢过程钢水硅质量分数控制在0.05%以上，并借助渣洗脱硫工艺，可以稳定生产硫质量分数小于0.002%的管线钢。此外，基于耦合反应动力学模型，通过将Al-O反应、Si-O反应、脱硫反应和Fe-O反应进行耦合，得到钢中硅质量分数是通过影响界面氧活度来影响渣洗脱硫效果。在钢水氧活度变化不大的条件下，界面氧活度主要取决于炉渣氧化性，而从炉渣成分中可以看出，硅质量分数小于0.05%的钢种对应的炉渣氧化性要高于硅质量分数大于0.05%的钢种，这与模型计算结果相一致。

Influence of silicon content in steel on tapping slag infiltration desulfurization

The industrial experiments of 21 heats were conducted at a commercial steel plant to analyze the efficiency of desulfurization during tapping slag infiltration. The results show that the influence of silicon in the steel on the tapping slag infiltration desulfurization was significant for the steel with the aluminum content of 0.025%-0.045%and the sulfur content of 0.002%-0.003%,while the influence of manganese content in the steel on the tapping slag infiltration desul-furization was not apparent. The sulfur content of pipeline steel can be controlled stably below 0.002%in the present pro-cess of tapping slag infiltration when the silicon content in steel was controlled above 0.05%. Moreover,the reactions of Al-O,Si-O,CaO-S and Fe-O were coupled based on the coupled reaction kinetics model and it shows the silicon con-tent in steel influences the desulfurization effect during tapping by influencing the oxygen activity at the interface be-tween slag and steel. The oxygen activity at the interface between slag and steel was determined by the oxidability of slag when the oxygen activity of molten steel was certain,and the compositions of slag after tapping slag infiltration de-sulfurization show that the oxidability of slag with the less than 0.05%silicon content is higher than that with the silicon content beyond 0.05% in steel,which was consistent with the calculated results.