钒钛磁铁矿煤基直接还原试验

Direct reduction of coal based vanadium-bearing titanomagnetite

为探明钒钛磁铁矿直接还原过程及其影响因素,研究了不同还原温度、不同还原时间、不同配碳比对钒钛磁铁矿含碳团块直接还原过程的影响,并通过XRD分析方法对还原机理进行了分析。研究结果表明,在一定条件下,直接还原团块金属化率随温度升高而升高,但还原温度超过1 200℃后,金属化率增幅逐渐减少,这是由于还原温度高于1 200℃后,金属化团块内铁氧化物的还原逐渐趋于平缓,而铁钛化合物的还原较为缓慢;团块金属化率随反应时间的延长和配碳比的升高均呈现了先升高后降低的趋势,这主要是由于反应时间过长使得金属化团块发生了再氧化及煤粉配入量过大导致带入灰分较多,在一定程度上阻碍了还原反应的顺利进行,从而导致金属化率降低。

In order to investigate the influence factors and reduction behavior of vanadium-bearing titanomagnetite,the influences of reduction temperature,reduction time and n（C）/n（O） on the reduction process of carbon composite briquettes of vanadium-bearing titanomagnetite were studied,and the XRD was used for analyzing the reduction mechanism of carbon composite briquettes of vanadium-bearing titanomagnetite. The results show that under certain conditions the metallization rate increases with the rise of reduction temperature,but the metallization rate increases gently after1 200 ℃,because the reduction reaction of iron oxides becomes gently after 1 200 ℃,and titanium iron compounds are difficult to be broken. With the increase of reduction time and n（C）/n（O）,the metallization rate increases firstly and then decreases,because the reduction time lasts too long,the reoxidation of metallized briquettes can not be avoided,and the high n（C）/n（O） leads to too much ash in metallized briquettes.It has an effect on reduction process,so the metallization rate of metallized briquettes decreases.