电弧炉配加直接还原铁对炼钢的影响

Effect of Adding Direct Reduced Iron to EAF on Steelmaking

通过开展全废钢及配加10%、20%、30%比例直接还原铁(DRI,direct reduced iron)试验研究了Consteel电弧炉配加不同比例DRI对冶炼技术经济指标、钢水洁净度和电弧炉终渣成分的影响,并根据试验情况对金属料加入、吹氧喷碳、造渣辅料加入、排渣等冶炼控制要点进行分析。结果表明,随着DRI加入比例增加,电耗、钢铁料消耗、造渣辅料消耗和渣量等逐渐增加。且DRI加入比例在30%时,因炉渣量较大,在冶炼过程中后期有炉渣从炉门溢出。同时,电弧炉配加DRI后钢水洁净度明显升高,电弧炉冶炼终点氮、磷、硫和残余元素质量分数降低,且随着DRI加入比例增加,电弧炉终点钢水氮质量分数下降速率变小。此外,随着DRI加入比例增加,电弧炉终渣FeO质量分数呈降低趋势。DRI加入比例20%时效果较好,冶炼周期较短,与全废钢炉次相比电耗增加不高,且氮和残余元素含量较低,满足大部分钢种要求。

The effects of adding different ratios of DRI(direct reduced iron)to Consteel EAF on smelting technical and economic indicators,molten steel cleanliness,and the ingredients of acr furnace final slag were studied by conducting experiments on all scrap steel and adding 10%,20%,and 30%ratios of DRI.And based on the experimental results,the key points of smelting control such as adding metal materials,blowing oxygen and carbon,adding slag making auxiliary materials,and slag discharge were analyzed.The results show that as the proportion of DRI added increases,the consumption of electricity,steel material,slag making auxiliary material,and slag amount gradually increase.When the proportion of DRI addition is 30%,due to the large amount of slag,slag overflows from the furnace door in the middle and late smelting process;At the same time,the cleanliness of the molten steel significantly increases after adding DRI to the EAF,and the mass fraction of nitrogen,phosphorus,sulfur and residual elements at the end of EAF smelting is reduced.And as the proportion of DRI added increases,the rate of decrease in nitrogen mass fraction at the endpoint of the electric furnace decreases.In addition,with the increase of DRI addition ratio,the FeO mass fraction of final slag showed a decreasing trend.When DRI is added at a proprotion of 20%,the effect is better,the smelting cycle is lower,the increase in electricity consumption is not high compared to the total scrap steel furnace,and the nitrogen and residual element content is lower,meeting the requirements of most steel grades.