小颗粒石灰石高温快速煅烧微观组织演变行为研究

Research on microstructure evolution behavior of small particle limestone during rapid calcination at high temperature

采用热重分析技术和扫描电镜,研究了小颗粒石灰石在转炉炼钢温度下快速煅烧分解的微观组织行为演变。研究表明:平均粒径在0.13~1.5 mm的石灰石颗粒转化率比较相似,比粒径小于0.13 mm和大于1.5 mm的石灰石颗粒转化速率更快。平均粒径小于0.074 mm的石灰石颗粒在高温下快速煅烧,会出现快速粘结,抑制转化速率。随着煅烧时间的增长,CaO晶粒逐渐长大,晶粒间的气孔先增多增大后又开始收缩;平均粒径为0.84 mm的石灰石颗粒在1 350℃下快速煅烧60 s时,出现大量气孔,形成高活性石灰。

Using thermogravimetric analysis technology and scanning electron microscope, the evolution of microstructure behavior of small particles of limestone during rapid calcination and decomposition at converter steelmaking temperature was studied. Studies have shown that the conversion rate of limestone particles with an average particle size of 0.13 to 1.5 mm is relatively similar, which is faster than that of limestone particles with a particle size of less than 0.13 mm and larger than 1.5 mm. Limestone particles with an average particle size of less than 0.074 mm are quickly calcined at high temperatures, which will cause rapid bonding and inhibit the conversion rate. As the calcination time increases, the CaO grains gradually grow, and the pores between the grains first increase and then begin to shrink.When the limestone particles with an average particle size of 0.84 mm are rapidly calcined at 1 350 ℃ for 60 s, a large number of pores appear, and high active lime is formed.