石灰石对转炉冶炼效果的影响

Influence of limestone on metallurgical effect of converter

在实验室条件下对石灰石和石灰块在转炉初期渣的溶解状况进行研究。结果表明,在1 550℃,加入石灰块与部分初期渣反应,仍为固相,没有形成液相;加入的石灰石块已完全溶解在转炉初期渣中,形成均质的液态渣。在工业试验中,分别在转炉前期和中后期加入石灰石考察其熔化状况及脱磷效果,结果显示,吹炼前期加入石灰石的炉次,吹炼前期形成的炉渣碱度较低,约为1.5左右,吹炼终点炉渣碱度才达到预期的指标,脱磷效果前期不佳,中后期才有所提高;中后期加入石灰石的炉次,吹炼过程能够保持较高的炉渣碱度,有利于保持稳定的脱磷效果。

The dissolving status of limestone and lime in the initial BOF slag was studied in the laboratory.The results showed that the lime block reacted with the partial initial BOF slag at 1 550℃,however the produced phase was still solid and no liquid phase was formed.The limestone block was completely soluble in the initial BOF slag and the homogeneous liquid slag was formed.In the industrial tests the limestone was added into converter at the earlier stage and middle-late period.The melting status and dephosphorization effect were investigated.The result showed that when adding limestone at the earlier stage,the basicity of the formed slag was lower,about 1.5at the earlier stage and reached expected indexes at the smelting end-point.The dephosphorization effects at the earlier stage were unsatisfactory and improved at the middle and late period.When adding limestone at the middle and late period,the slag basicity kept higher value during blowing process,which can be beneficial to obtain stable dephosphorization rate.