关键词: 还原气氛, 还原温度, 氧化球团, 还原粉化, 抗压强度

Abstract: Cracking and degradation in the reduction process of iron ore oxidized pellets has serious influence on production. The effect of reduction temperature and reducing atmosphere on reduction degradation performance of oxidized pellet and the compressive strength of reduced pellet was investigated. And the reduction degradation is analyzed based on the inner microstructure pictures of the reduced pellets by Leica DMRXP microscope. The results indicate that RDI+6.3 and RDI+3.15 decreased while RDI-0.5 increased as the reduction temperature increases from 450 ℃ to 550 ℃ in gas-based direct reduction process. When the reduction temperature raises to 600 ℃，RDI+6.3 and RDI+3.15 begins to increase while RDI-0.5 decrease. When the volume ratio of H2/(H2+CO) increases，RDI+6.3 and RDI+3.15 increased，while RDI-0.5 decreased dramatically. The temperature and reducing atmosphere have an inverse effect on compressive strength of reduced pellets and the low temperature reduction degradation rate of oxidized pellet. Namely，the compressive strength of reduced pellets increased when reduction degradation rate of oxidized pellet decreased，and the compressive strength of reduced pellets decreased when reduction degradation rate increased.

Key words: Reduction atmosphere, Reduction temperature, Oxidized pellet, Reduction degradation, Compressive strength