Effects of the Composition of Residual Materials from Steelwork on the Crushing Strength of DRI

Abstract

The goal of this study is to investigate the effects of the composition of residual materials, such as the basicity and (C/Ored)mol, as well as the reduction temperature and time, on the crushing strength of direct reduced iron (DRI) under the carbothermic reduction through the rotary hearth furnace (RHF) process. Laboratory- scale experiments were executed to examine the DRI quality in the RHF operation. It is observed that when the composition of residual materials varies or the reduction temperature and time decrease, DRI crushing strength becomes lower than the 60 kg/piece requirement for blast furnace feed stock. Both basicity and (C/Ored)mol of the residual materials would affect the crushing strength of DRI. As B2 increase, the crushing strength of DRI also rises, and the maximum value is when the basicity is 1.4. The result shows that as the value of (C/Ored)mol rose above 1.20, the DRI strength declined.