钒钛磁铁矿含碳球团的还原机制

 以转底炉工艺为基础，对不同配碳比、不同焙烧温度、不同焙烧时间条件下的金属化球团宏观形貌和内部组织结构进行分析研究。结果表明：随着还原温度的升高，Ti在球团中由集中分布到均匀分布再到集中分布，与Fe逐渐分离，而Ti与Mg的分布状态几乎相同，且V的赋存形态几乎与Ti一致。通过扫描电镜观察及分析得知，随着还原温度的升高，球团孔隙度降低，这在一定程度上影响了还原反应的继续进行。还原时间为20~40min时，Fe与Ti、V基本能够分开，Mg与Ti则基本互溶在一起，走向一致。无论在何种配碳比的条件下，球团中均出现了金属铁和(Fe,Mg)Ti2O5，而黑钛石的存在限制了金属化率的进一步升高，且当配碳比增加到1.3时，球团中出现了新相TiC0.2N0.8。

Reduction Mechanism of Vanadium Titano-Magnetite Carbon Composite Pellets

On basis of RHF(rotary hearth furnace) technology,the macro morphology and inner microstructure was investigated under the conditions of different carbon ratio,different roasting temperature and different roasting time.The results show that: with increase in reduction temperature,Ti in the pellets is firstly centralized distribution,and then uniformed distribution,finally centralized distribution;Fe element is gradually separated,Ti and Mg distribution is almost the same,and the V forms almost consistent with Ti.The porosity of pellet is decreased with increase in reduction temperature through observation and analysis by SEM,which can to some degree have effect on reduction process.If the reduction time is controlled about 20 to 40 minutes,Fe and Ti,V can be separated,however Mg and Ti are immiscible together.No matter what proportions of carbon condition,pellets exist metallic iron and(Fe,Mg)Ti2O5.Titanium black stone will limit increase in the metallization rate,and when the w(C)/w(O) is up to 1.3,the new phase of TiC0.2N0.8 appears in pellet.