Effects of different atmosphere on reaction behaviors of metallised burden

Abstract

ABSTRACT The utilisation of metallised burden in blast furnace (BF) as a way of CO2 emission reduction has been widely considered. One of the major concerns is its reoxidation by CO2 in the upper part of BFs. In this study, the non-isothermal reaction behaviours of metallised burden with a metallisation ratio of 70% in different CO2 + CO gas mixtures were analysed. The results showed that the metallised burden can be oxidised by CO2 under sufficiently large CO2 partial pressure. In a 50%CO2 + 50%CO gas mixture, Fe was oxidised to FeO. And the reaction started at 718°C, which is much higher than the temperature in the upper shaft of BFs. The metallised burden cannot be oxidised by CO2 in the low temperature zone of BFs. During the descent of the burden, temperature increases and the reduction atmosphere strengthens in an actual BF. The CO2 partial pressure is insufficient to oxidise the metallised burden.