高铁低硅高料层烧结研究

A STUDY OF HIGH IRON AND LOW SILICA SINTERING AT DEEP BED

高铁低硅烧结矿是强化高炉炼铁的优质炉料 ,但随烧结矿铁品位升高及二氧化硅含量降低 ,其强度变差。本文研究了在高料层 ( 70 0～ 80 0mm)条件下高铁低硅料的烧结特性。包括铁品位、硅含量 ( 3 8%～ 4 5 % )、料层厚度 ( 70 0～ 80 0mm)及添加蛇纹石对烧结矿产质量的影响。并就各种条件下烧结矿的矿物组成及冶金性能进行了对比。结果表明 ,随料层厚度增加 ,烧结矿转鼓强度升高 ,固体燃耗下降。在高料层 ( 75 0mm)及添加 1 3%蛇纹石的条件下进行高铁低硅烧结 ,则效果更佳。因此 。

High iron and low silica sinter is a quality feed to enhance the ironmaking in blast furnace. However, the sinter strength deteriorates with an increase in iron grade and a decrease in silica content. In this paper,a study of fabrication of high iron and low silica sinter containing 58.5%～60.5% TFe and 3.8%～4.5% silica content was conducted at 700 mm～800 mm bed height and with the addition of serpentine in the sinter mix, which included the effect of process factors on strength and productivity of finished sinter,sinter mineralogy and metallurgical properties.The base case sintering experiment was performed under the conditions of 600 mm bed height and without proportioning of serpentine in the sinter mix.It was shown that high bed sintering is of importance to enhance strength and productivity of sinter and reduce coke consumption. Compared with the results of bass case,TI and coke consumption are increased by 2.26%and decreased by 3.12 kg/t respectively at bed 750?mmbed height and without adding serpentine.However,TI and coke consumption are increased by 4.45% and decreased by 3.59 kg/t respectively at 750?mm bed height and with adding 1.3% serpentine in sinter mix compared with that of base case. The mechanism is demonstrated that oxygen potential of bed increases and the induration time of minerals at high temperature zone extends during high bed sintering with less coke content proportioned,resulting in 2.3%～3.3% and 1.89%～2.33%increases in calcium ferrite content and reducibility index,respectively.