Increasing the Mixing Rate of Metalized Pellets in Blast Furnace Based on the High-temperature Interactivity of Iron Bearing Materials

Abstract

The softening and melting dripping properties of increasing mixed rate of metalized pellets were investigated. The experimental results showed that the softening and melting properties of the lump ores or oxidized pellets were dramatically improved by interaction between lump ores (or oxidized pellets) and metalized pellets, while there was no obvious interaction between sinters and metalized pellets. On the basis of the constant basicity of mixed burden, the softening and melting start temperatures reduced and softening and melting interval became wide as the mixing rate of metalized pellets was increasing from 0% to 56%. The influence of the mixed rate of metalized pellets, less than 25%, on the properties of mixed burden is little. When the rate was more than 25%, the properties of mixed burden would rapidly deteriorate. With a large number of metalized pellets, especially 56% sinters replaced, the properties of mixed burden were worst. According to the element migration of burden interface observed, it was found that the diffusion of Ca and Si between oxidized pellets and sinters (or metalized pellets) was obvious. However, the phenomenon between metalized pellets and sinters was weaker. Thus, it was confirmed that the strong interaction must happen between burdens, the nature differences of which were larger.