7TH EUROPEAN COKE AND IRONMAKING CONGRESS - ECIC 2016

It is of significant importance to utilize the in-plant iron-bearing dust and mud of steel mills which are characterized by high iron and carbon content, and some toxic metals such as lead and zinc etc. In this paper the conditions of new process of metallizing sintering of pellets were optimized to manufacture pre-reduced sinter. Under the conditions of C/Fe ratio of 0.5 (50% coal blended in the pellet feed), 18% moisture of green ball, bed height of 400mm and air speed of 0.4 m/s, the pre-reduced sinter product, assaying 60.53% Fe and the iron metallization degree of 45.23%, was produced, and the removal rate of Zn, Pb and As was obtained at 92.78%, 96.37% and 62.45%, respectively. The sintering index of unit productivity of 0.471 t·m-2·h-1, tumble index of 81.31%, and solid fuel consumption of 309.67 kg·t-1, were achieved respectively. The reducibility index and reduction disintegration index (RDI+3.15) of pre-reduced product are 80.69% and 96.45%. All of which prove that the pre-reduced sinter product is the high quality burden for blast furnace. The toxic metals were precipitated in the dust of sintering flue gas, containing 51.49% ZnO, 3.15% PbO and 1.45% As2O5.