用硫铁矿烧渣制取海绵铁的碳还原过程  

Carbon reduction process in preparation of sponge iron using pyrite cinder

作　　者：龚竹青[1] 龚胜[1] 陈白珍[1] 周波[2] 

机构地区：[1]中南大学冶金科学与工程学院,湖南长沙410083 [2]广西大学资源与环境工程学院,广西南宁530004

出　　处：《中南大学学报（自然科学版）》2006年第4期703-708,共6页Journal of Central South University:Science and Technology

摘　　要：对硫铁矿烧渣的碳还原过程进行研究。热力学分析结果表明：碳的气化反应在850℃以上可以进行，1000℃时气相平衡组成中CO体积分数接近100％，在此条件下Fe2O3可迅速经Fe3O4和FeO还原成金属铁；反应温度对还原过程影响十分明显，900℃以下时铁的金属化率很低，海绵铁的制取应在950℃以上。X射线衍射结果表明：950℃以下时Fe2O3很难完全还原，于980℃还原焙烧0．5h，Fe2O3的衍射峰消失；焙烧1.5h，已出现α—Fe衍射峰，Fe3O4的衍射峰消失，还出现Fe2SiO4的衍射峰，这表明烧渣的还原过程是按Fe2O3→Fe2O3→FeO→Fe的顺序进行的，FeO还原成Fe的速度最慢，是过程的控制步骤；CaCO3脱S效果明显，且是固体碳气化的促进剂，可提高铁氧化物的还原速度，在同样反应条件下使铁金属化率提高2％～3％。The carbon reduction process of pyrite cinder was studied. The thermodynamic results show that the gasification of carbon occurs quickly above 850℃. The volume fraction of CO is close to 100% and Fe2O3 is reduced to Fe via Fe3O4 and FeO when the reaction temperature is 1 000 ℃. The experimental results show that the effects of reaction temperature on the reducing process are dominant. The metallization rate of iron lowers when temperature is below 900 ℃. Therefore, sponge iron should be prepared above 950℃. The X-ray diffraction results show that Fe2O3 is partly reduced below 950 ℃, Fe2O3 phase in calcinations sample disappears at 980 ℃ for 0.5 h, a-Fe phase appears and Fe3O4 phase disappears at 980 ℃ for 1.5 h. The cinder reduction reaction occurs in the sequence of Fe2O3→Fe3O4→FeO→Fe and the rate-determining step is FeO→Fe. When CaCO3 is used as desulfurizer and accelerant for gasification of solid carbon, reduction rate of iron oxides is improved and the metallization rate of iron oxides is increased by 2%- 3%.

关 键 词：硫铁矿烧渣 海绵铁 金属化率 

分 类 号：TF556[冶金工程—钢铁冶金]