Effect of Adding Direct Reduced Iron to EAF on Steelmaking

Abstract

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.

Keywords

• consteel eaf； dri； technical and economic indicators； cleanliness； final slag of eaf