含钛精矿用于鞍钢球团的试验研究

Experimental study on applying titanium-containing concentrate to Angang steel pelletization

为探索将含钛精矿配加到鞍钢卡拉拉精矿中进行球团生产的可行性,考察了膨润土配比、含钛精矿配比和焙烧温度对含钛球团性能的影响。结果表明:在含钛磁铁矿配比为5%~25%条件下,添加1.3%~1.5%的膨润土,可制得满足生产要求的生球;焙烧温度与含钛磁铁矿配比对成品球的抗压强度具有重要的影响,随着焙烧温度升高,抗压强度先增大后减小,在1200℃左右达到最大值,同时增加含钛磁铁矿的配比可提高抗压强度上升幅度。从球团矿相的角度出发,采用偏光显微镜、扫描电镜(SEM+EDS)和电子探针(EPMA)等分析测试方法,分析了添加含钛磁铁矿降低球团适宜焙烧温度及含钛球团与普通球团强度差异的内在机理,发现在1150℃时生成了钛赤铁矿,球团获得了强度来源,而高温下TFe(全铁)的氧化再结晶能力差,球团抗压强度降低,因此含钛球团的适宜焙烧温度较低;而含钛球团中钛赤铁矿较粗大,氧化再结晶能力较弱,相反普通球团具有大量细而均匀的磁铁矿晶粒,因此强度较普通球团低。

In order to explore the feasibility of adding titanium concentrate to Angang Karala concentrate for pelletizing,the effects of bentonite ratio,titanium concentrate ratio and roasting temperature on the properties of titanium-bearing pellets were investigated.The results show that the qualified green pellets could be prepared with 5% to 25% titan magnetite and 1.3% to 1.5% bentonite in terms of mass fraction.The roasting temperature and the mass faction of titanomagnetite played an important role in the compressive strength of the finished ball.As the roasting temperature increased,the compressive strength first increased and then decreased,reaching the maximum value at about 1200℃.From the perspective of mineralogical phase,the mechanism of relatively low roasting temperature of titanium-bearing pellets as well as the difference between their strength and that of ordinary ones was studied by means of polarization microscope,SEM,EDS and EPMA.It is found that titanium-bearing pellets have low roasting temperature due to the formation of ilmenite at 1150℃,which could provide intensity in the pellets.Furthermore,the oxidative recrystallization at high temperature is poor.Compared with the ordinary pellets which have a large number of fine and uniform magnetite grains,the ilmenite in the titaniumbearing pellets is large,resulting in their weak oxidative recrystallization,and their strength is lower than that of the ordinary pellets.