摘要
包头铁精矿球团中含有钾、钠等碱金属有害元素,造成球团还原异常膨胀。添加MgO,可有效降低球团的还原膨胀率。采用压团、焙烧和分段还原法测量铁氧化物各还原阶段的还原膨胀率,采用光学显微镜及SEM观察焙烧试样和还原产物的形貌。研究结果表明,MgO促进了铁酸镁或磁铁矿的形成,并导致Na偏聚析出,抑制了Fe_(2)O_(3)→Fe_(3)O_(4)阶段的还原膨胀率。MgO抑制了浮氏体的层状定向结晶,并生成了高熔点渣相,降低了Fe_(3)O_(4)→Fe_(x)O阶段的还原膨胀率。添加MgO后,稳定了浮氏体晶格,减少了晶体缺陷,使Na从铁氧化物中析出,抑制铁晶须生长,抑制球团Fe_(x)O→Fe阶段的还原膨胀率。
The harmful elements K,Na in iron ore from Baotou will result in abnormal reduction swelling of pellet which can be resisted effectively by the MgO content.The reduction swelling index in stages(Fe_(2)O_(3)→Fe_(3)O_(4),Fe_(3)O_(4)→Fe_(x)O,Fe_(x)O→Fe)was measured,the optical microscope and scanning electron microscope were used to study the morphology of roasting and reduction samples.It was found that MgO promoted the formation of magnesium ferrite and sup-pressed the reduction swelling index of sample with 0.3%F content during Fe_(2)O_(3)→Fe_(3)O_(4).While the reduction swelling rate was accelerated by MgO in sample with 0.6%F content during Fe_(2)O_(3)→Fe_(3)O_(4).The effect of MgO content on the reduction swelling index during the transformation of Fe_(3)O_(4)→Fe_(x)O was i MPacted by the content difference of K,Na.MgO inhibits the reduction swelling rate of the third stage by suppressing the growth of iron whiskers.
作者
刘安康
范晓晶
Liu Ankang;Fan Xiaojing(Hebei All-joint Energy and Environmental Protection Technology Co.,Ltd.,Shijiazhuang Hebei 050000,China)
出处
《山西冶金》
2025年第8期59-63,共5页
Shanxi Metallurgy
