Cold Strength and High Temperature Behaviors of Self-Reducing Briquette Containing Electric Arc Furnace Dust and Anthracite

Abstract

Electric arc furnace dust (EAFD) is one of the by-products of steelmaking industry. This research aims at dealing with EAFD by pyrometallurgy through mixing it with anthracite to be used as carbon-containing briquettes in RHF. The effect of the briquetting parameters on the green pellet strength was investigated in this paper. Effects of reduction temperature, reduction time and C/O molar ratio on metallization rate and removal rate of element Zn were also studied respectively. The results showed that: Effect of different factors on the drop number was greater than the compressive strength of briquettes. Green briquette drop number was more sensitive to moisture content and bentonite content. Given 2 wt% content of bentonite, 70 MPa pressure and 1.0 mole ratio of C/O, the drop number of the green pellets increased from 1.4 times to 6.4 times by water content changed from 4 to 10 wt%. Zinc and iron compounds are both easy to be reduced by anthracite. When the reduction temperature is up to 1200°C, the zinc can be rapidly reduced within 5 min. But if the temperature reduced by 100°C, the total removal time would be prolonged to 20 min. The iron-containing phases were mainly Fe, Ca₂Fe₂O₅ and a small amount of FeO after high temperature reduction. When reduction temperature, reduction time, C/O molar ratio were 1200°C, 20 min and 1.1 respectively, direct reduction iron was most concentrated.