摘要钢水炉外精炼具有改善钢材质量、提高钢液纯净度、去除有害夹杂、降低 能耗等作用。研究合适的 LF 精炼渣具有重要的工程意义和理论参考价值，对 于 LF 精炼来说，合适的精炼渣成分和碱度以及吹氩流量对精炼过程的脱硫效 果和优化钢液质量具有重要的影响。84433

本文通过分析精炼渣各组分对钢液质量的影响，使用 LF 虚拟仿真系统进 行模拟试验，对钢液进行脱硫试验，优化精炼渣成分，并确定 LF 炉精炼渣合 适的碱度。同时调整精炼过程中的吹氩流量，研究其对于钢液成分的影响，确 定较佳的吹氩量。通过上述模拟试验，得到的主要结论如下：

(1)随着精炼渣碱度增大，LF 精炼后钢液中的 S 含量呈下降趋势，即脱硫效 果变好。但是当碱度进一步增大时，钢液中的 S 含量反而开始增加，脱硫效果 减弱。

(2)虽然 A12O3 本身呈酸性且基本无脱硫作用，但是随着其含量的增加，能 够改善渣的流动性，促进脱硫反应的进行，改善脱硫效果，但过高的 A12O3 含 量也会带入较多的夹杂，反而不利于脱硫。

(3)MgO 对于改善精炼渣的脱硫效果有益，但其含量过高，也会恶化脱硫反 应的动力学条件，不利于精炼渣脱硫。

(4)CaF2 能够降低精炼渣的粘度，改善渣的流动性，增加钢-渣间的传质， 有利于脱硫反应。另一方面 CaF2 会侵蚀炉衬，一味的追求脱硫效果增大 CaF2 含量也是不可取的。

(5)LF 精炼渣脱硫试验发现一种脱硫效果较好的渣型，其成分含量为 CaO- 50%，SiO2-16%，Al2O3-20%，MgO-10%，CaF2-4%，二元碱度和四元碱度分别 为 3。12 和 1。76。

(6)吹氩试验发现底吹氩搅拌能够促进钢-渣反应，较大的氩气流量能够取得 更好的脱硫效果，但是过高的氩气流量会导致钢液面裸露，使钢液中的气体和 夹杂物增加，影响脱硫效果，因此，底吹氩流量应控制在 20 m3/h，可以得到最 佳的脱硫效果。

毕业论文关键词：炉外精炼；LF 精炼技术；精炼渣优化；模拟仿真

Abstract Molten steel refining can improve steel quality, improve the purity of molten steel, removing harmful inclusions and reduce energy consumption etc。。 The study of suitable LF refining slag has important engineering significance and theoretical reference value。 For LF refining, the appropriate refining slag composition and alkalinity, and blowing argon flow rate on the refining process of desulfurization effect and optimize the quality of liquid steel has an important influence。

This paper through the analysis of refining slag in each group effects on the quality of the steel liquid, using lf virtual simulation system for simulation test, on liquid steel for desulfurization test and optimization of refining slag composition, and to determine the LF refining furnace slag suitable basicity。 At the same time, the flow rate of argon blowing in the refining process was adjusted, and the influence of the composition of the liquid steel was studied。 The main results obtained are as follows:

(1)With the increase of basicity of refining slag, the content of S in molten steel after LF refining showed a decreasing trend, that is, the effect of desulfurization was better。 But when the alkalinity is further increased, the S content in the steel liquid increases, and the desulfurization effect is weakened。

(2)Although A12O3 itself is acid and basic without desulfurization effect, but with the increase of the content to improve the slag fluidity, promote the desulfurization reaction, improve the desulfurization effect, but too high content of Al2O3  will bring more inclusions, but not conducive to desulfurization。

(3)MgO is beneficial to improve the desulfurization effect of refining slag, but its content is too high, it will deteriorate the dynamic conditions of desulfurization reaction, is not conducive to the desulfurization of refining slag。