研磨时间对熔盐法合成铁铝尖晶石粉体的影响

Effect of grinding time on synthesis of hercynite powder by molten salt method

为了研究原料混合粉的研磨时间对熔盐法合成铁铝尖晶石的影响,以无水乙醇为研磨介质,将按一定配比配制的工业氧化铝粉、铁精矿粉、石墨粉、氯化钠混合粉在行星球磨机中分别球磨0、3、6、9和12 h,干燥后在1100℃氮气气氛中保温3 h煅烧,再经超声波水洗、过滤、干燥制得合成铁铝尖晶石粉,然后进行XRD、SEM和EDS分析。结果表明:1)采用研磨不同时间的原料混合粉合成的铁铝尖晶石粉均以铁铝尖晶石为主晶相,并含有少量方钠石相;随着研磨时间的延长,原料混合粉的粒度减小,合成铁铝尖晶石粉中铁铝尖晶石相增多,方钠石相减少。2)熔盐法合成铁铝尖晶石的过程以"模板生长"机制为主导。3)研磨时间延长使原料粒度减小,既促进了铁铝尖晶石的合成,又抑制了方钠石的形成。

In order to research the effect of the grinding time on the synthesis of hercynite by the molten salt method,the hercynite powder was prepared using anhydrous ethanol as the grinding medium,industrial alumina powder,iron ore concentrate powder,graphite powder and sodium chloride as the starting materials,mixing according to a certain proportion and grinding in a planetary ball mill for 0,3,6,9,and 12 h,respectively,after drying,firing at 1100℃for 3 h in nitrogen atmosphere,then ultrasonic washing,filtration and drying.Then the XRD,SEM and EDS analyses were carried out.The results show that:(1)all hercynite powders synthesized with different grinding time were mainly composed of hercynite and a small amount of sodalite;with the grinding time prolonging,the particle size of the mixed powder reduces,the hercynite content increases and the sodalite content decreases;(2)the synthesis of hercynite by the molten salt method is dominated by the“template formation”mechanism;(3)prolonging the grinding time reduces the particle size of the raw materials,which not only promotes the synthesis of hercynite,but also inhibits the formation of sodalite.