铁矿石内配煤制粒小球动态干燥过程的破裂、粉碎会严重影响还原效果。为提高小球干燥过程的热态强度,研究了含钠添加剂对铁矿石内配煤小球动态干燥升温过程热态强度的影响,并结合含钠添加剂对内配煤、铁矿石和膨润土Zeta电位的影响研究以及动态干燥小球的内部环境扫描电镜分析,探讨了含钠添加剂对制粒小球热态强度影响的机理。结果表明:①含钠添加剂可通过改善小球主要原料颗粒表面的亲水性来强化膨润土的黏附作用,从而使小球内部结构致密,热态强度提高。②添加剂配加量为3%时,动态干燥粉化率为5.23%,动态干燥小球的落下强度、抗压强度和群落粉化率分别为3.1次、10.88N/个和3.26%,与不配加添加剂相比,各项指标显著改善。
The rupture and crushing of iron ore coal-containing mini-pellets will seriously affect the reduction of pellets in the dynamic drying. Effects of sodium additives on the heat strength of iron ore coal-containing mini-pellets in the dynamic dr- ying were studied in order to improve heat strength of mini-pellets. The behaviors of heat strength of mini-pellets improved by sodium additive were investigated by using scanning electron microscopy to analyze inside of dynamic dry pellets and the influ- ence of Zeta potential of coal-containing, iron ore and bentonite with sodium additives, then the mechanism of heat strength of pellets affected by sodium additives were expounded. The results showed that adding sodium additive can improve surface hy- drophilieity of the particles,inhance the adhension role by bentonite, the ball inside will more dense, heat strength of dynamic were improved. With 3% additives, the dynamic drying degradation index of the dynamic drying pellet was 5.23%, and the compressive strength, the drop strength of dynamic drying mini-pellets and the quantity drop degradation index reached 10.88 N/P ,3.1 times, and 3.26% respectively. Compared with the mini-pellets without additives,its index was improved significant- ly.