Improvement of Strength of Preheated Pellet with Small Addition of Sodium Silicate

摘要

In the iron ore pelletizing process of grate-kiln system for induration, pellets are indurated at about 1000 deg C within a traveling grate and then at about 1200 deg C within a rotary kiln. It is very important for pelletizing process to increase strength of preheated pellet, which means the pellet crushing strength before a rotary kiln, in order to prevent the collapse of pellets in a rotary kiln. Therefore, to strengthen pellets sufficiently within a traveling grate with shorter time, an application of liquid phase sintering method to palletizing process was studied experimentally with addition of sodium silicate solution. The results are summarized as following:(1)The strength of preheated pellets was increased by addition of dilute sodium silicate solution with low melting temperature.(2)The strength of preheated pellets with addition of sodium silicate solution for granulating water, was much more increased than that with addition of solid sodium silicate.(3)Addition of sodium silicate solution did not influence on reducibility, reduction degradation index and reduction test under load of pellets.