钒钛磁铁矿含碳球团还原的影响因素

Influencing factors of the reduction of vanadium titano-magnetite carbon composite pellets

通过单因素实验考察了还原温度、还原时间及碳氧摩尔比(nC/nO)对钒钛磁铁矿含碳球团还原的影响,结合扫描电镜照片解释了钒钛磁铁矿的还原机理.实验结果表明,适当升高还原温度、延长还原时间及增加碳氧摩尔比均可以促进钒钛磁铁矿的还原,并且金属化率随还原温度的升高先急剧升高而后趋于平缓,随着还原时间的延长及碳氧摩尔比的增加而先升高后降低,而残碳量随着反应的进行不断降低.当还原温度为1350℃,还原时间为30 min,碳氧摩尔比为1.2时,球团的金属化率达到最大值.通过扫描电镜照片可以看出,球团在还原过程中形成了铁连晶,并且在不同的还原条件下铁连晶的大小及形态不同.

The influences of reduction temperature,reduction time and the C/O molar ratio on the reduction of vanadium titano-magnetite carbon composite pellets were investigated by single factor experiments.The mechanism of reduction was explained in combination with scanning electron microscopy（SEM）.Raising the reduction temperature,prolonging the reduction time and increasing the C/O molar ratio properly can promote the reduction of vanadium titano-magnetite.With the rise of reduction temperature,the metallization rate ascends quickly before 1 350 ℃ and gently then.With the increase of reduction time and C/O molar ratio,the metallization rate moves up firstly and then down,but the carbon residue content decreases with the reduction proceeding.When the reduction temperature is 1 350 ℃,the reduction time is 30 min and the C/O molar ratio is 1.2,the metallization rate of the pellets reaches the maximum.SEM observation shows that iron coupling crystals form in the reduction process,and their size and shape vary from each other under different reducing conditions.