THERMAL REDUCTION OF EAF DUSTS BY USING BF DUSTS AS A REDUCING AGENT

摘要

The investigation of the thermal reduction of Electric Arc Furnace Dust (EAFD) by Blast Furnace Dust (BFD) was carried out using simultaneous thermogravimetric analysis (STA) coupled with Quadrupole Mass Spectroscopy (QMS). Chemical and mineralogical analyses were also employed. EAF Dust, which mainly consists of higher zinc compounds as Zincite (ZnO) and Franklinite (ZnFe_2O_4), is produced in electric arc furnaces (EAF). Blast furnace dust (BFD) with a carbon-iron rich, flue by-product released in the iron-making process was used as a reductant agent. Both raw materials were examined individually in different controlled atmospheres of Ar, air and CO_2 between 20° and 1400°C. Different parameters such as effect of reaction atmosphere, temperature and quantity of the reductant agent were explored. The products of reaction were examined by x-ray diffraction (XRD) as well as the gaseous substances evolved in the reactions. The results indicated that, at 1300°C in Ar atmosphere, a complete reduction of oxide compounds contained in both samples is achieved with a 33 % reductant mixture.