Fe_(2)O_(3)对高硅碱性球团固结性能的影响

Influence of Fe_(2)O_(3)on consolidation properties of high silica alkaline pellets

深入研究Fe_(2)O_(3)对于高硅碱性球团生球以及成品球性能的影响,有助于促进基于我国铁矿资源特征的低碳炼铁技术发展。本文通过调整碱性球团用混合料中Fe_(2)O_(3)的含量,解析Fe_(2)O_(3)对高硅碱性球团生球、预热球和成品球性能的影响规律,并采用扫描电镜以及图像识别处理系统表征高硅碱性球团的微观矿相结构。结果表明:随着混匀矿中赤铁矿配比的提高,高硅碱性球团生球、预热球和成品球的抗压强度均有所降低,随着Fe_(2)O_(3)配比的升高,成球性能劣化,生球的抗压强度降低至9.04 N/P。赤铁矿连晶固结性能变差,成品球的强度降低至3433 N/P。当两种矿粉的配比为50%时,球团孔隙率急剧增大为32.8%,A矿粉配比不宜超过40%。微观矿相结果表明,随着Fe_(2)O_(3)含量的增加,球团内部小颗粒尺寸晶粒变多,大颗粒尺寸晶粒减少,平均颗粒面积减少,晶粒间连晶性能变差,固结性能削弱,内部孔隙率提高。在制备高硅碱性球团时,含Fe_(2)O_(3)的精矿粉配加不宜太高,会对球团矿的固结性能产生不利影响。

The in-depth research of the influence of Fe_(2)O_(3)on consolidation properties of high silica alkaline pellets fresh pellet and finished pellets is helpful to promote the development of low-carbon ironmaking technology based on the characteristics of iron ore resources in China.The influence of Fe_(2)O_(3)on the properties of high silica alkaline pellets in fresh pellets,preheated pellets and finished pellets is analyzed by adjusting the content of Fe_(2)O_(3)in the compound for alkaline pellets,and the microscopic mineral facies structure of high silica alkaline pellets is characterized by scanning electron microscope and image recognition processing system.The results show that with the increase of the hematite ratio in the mixed ore,the compressive strength of the high silica alkaline pellet fresh pellets,preheated pellets and finished pellets decreases,and with the increase of the ratio of Fe_(2)O_(3),the pelletizing properties deteriorate,and the compressive strength of the fresh pellets decreases to 9.04 N/P.The consolidation properties of hematite deterioration become worse,and the strength of the finished ball decreases to 3433 N/P.When the ratio of the two mineral powders is 50%,the porosity of the pellets increases sharply to 32.8%,and the ratio of A ore powder should not exceed 40%.The results of microscopic mineral facies show that with the increase of Fe_(2)O_(3)content,the small particle size in the pellet increases,the large particle size decreases,the average particle area decreases,the intergranular cohesion performance deteriorates,the consolidation performance weakens,and the internal porosity increases.In the preparation of high silica alkaline pellets,the addition of concentrate powder containing Fe_(2)O_(3)should not be too high,which will adversely affect the consolidation properties of pellets.