摘要
为研究钒钛磁铁矿-煤球团还原过程中挥发分作用,开展了N2气氛下分层试样与两类球团非等温热重还原实验。试样的还原度由失重测定。结果发现,煤粉中的挥发分于400℃左右开始挥发。钒钛磁铁矿-非焦煤球团还原过程非常复杂,可分为四个阶段:挥发分挥发产生CO、H2还原球团、挥发分挥发的CO、H2及其碳氢化合物分解产生的C、H2与固体C共同作用还原球团、C经由气化反应媒介作用还原球团、C直接还原球团。挥发分的挥发能提高球团的气孔率和还原性,但影响较小。分析表明,在四个还原阶段中,C的直接还原作用对球团的还原影响最强,球团的还原度提高率可达0.1748%·℃-1。
Specimens of separate layers of ore and coal and two kinds of pellets were carried out thermogravimetrically in a nitrogen atmosphere to study the effect of volatile on the reduction of vanadium-titanomagnetite coal mixed pellet.The reduction degree was measured by the weigh loss.The results are found that volatilization of coal takes place at the beginning of ～400℃.The reduction processes of the pellet are very complicated and may be divided into four stages： reduction by CO and H_2 from volatilization of coal;reduction via CO and H_2 in the volatile and C and H_2 generated by cracked hydrocarbon in the volatile and fixed carbon in coal,reduction by C via the intermediate of the carbon gasification reaction,and true direct reduction via C.The volatilization of coal can increase porosity and reducibility of the pellet,however,has a less effect on the reduction of pellet.The analysis shows that the effect of direct reduction of C on the reduction of pellet is the strongest in four stages,and the increased rate of the reduction degree of pellet can reach up to 0.1748%·℃^-1.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2011年第2期183-186,199,共5页
Journal of Materials Science and Engineering
基金
国家自然基金资助项目(50406012)
攀枝花学院重点教研教改资助项目(JJ0831)
关键词
钒钛磁铁矿煤球团
挥发分
非等温还原
还原度
Vanadium-titanomagnetite-coal mixed pellet
volatile
nonisothermal reduction
reduction degree
