转炉利用石灰石造渣炼钢的试验研究

基于对石灰石分解机理的分析,研究了炼钢过程中利用石灰石代替石灰进行造渣时炉内富余热量的变化,发现当采用全部石灰进行冶炼时,铁水加入比(质量分数)可达到86.1%左右,随着石灰石加入量的增加,废钢比降低,吨钢富余热量减少,石灰加入量降低.若全部采用石灰石进行造渣,铁水比最高可达到97.0%.在此基础上,利用60 t转炉研究了炼钢过程采用石灰石完全代替石灰进行造渣炼钢的冶金效果.实验发现：与采用石灰造渣炼钢相比,当采用石灰石进行造渣炼钢时,吹炼至4 min时的炉渣TFe质量分数为21.87%,碱度为1.22；随着吹炼时间增加,炉渣TFe含量降低,碱度上升至3.0以上.炼钢过程脱磷更加稳定且脱磷率提高了2.6%；平均终渣碱度为3.52,能满足冶炼的脱磷要求；渣量大幅度降低,从而降低了钢铁料消耗；吹炼时间略有延长,终点熔池温度基本保持不变.研究结果为调整炉料结构、降低生产成本提供了新的方法和思路.

Research on slagging by limestone during BOF steelmaking process

On the basis of analysis of limestone decomposing and slagging mechanism, the changing of surplus heat was studied using limestone instead of lime as the slagging agent during steelmaking process, which indicates that hot metal added ratio can reach approximate 86. 1% if using lime entirely. If limestone is applied in the steelmaking process to replace all limes for slagging, the hot metal ratio can reach up to 97. 0%. On this basis, the metallurgical results of using limestone instead of lime for slagging in 60 t con-verter were studied. The results show that the content of TFe in slag is 21. 87% at 4 min and the basicity is 1. 22 using limestone for slagging. With the blowing time increasing, the content of TFe reduces while the basicity increases to more than 3. 0. Besides, the de-phosphorization process is much more stable and the dephosphorization ratio increases by 2. 6%, and the average basicity of slag in the end is 3. 52, meeting the demand of dephosphorization. Since the slag amount substantially reduces, which results in the decline of the consumption of steel material. The blowing time is prolonged and the temperature of liquid steel is kept constant. Furthermore, the re-sults also provide a new method and concept for optimizing the charging material structure and reducing the production cost.