X.M. Yang
,
Y.S. Xie and D.G. Wang (Institute of Chemical Metallurgy
,
The Chinese Academy of Sciences
,
Beijing 100080
,
China) D.B. Huang
,
T.J. Yang and L.T. Kong (University of Science and Technology Beijing
,
Beijing 100083
,
China)
金属学报(英文版)
The reduction behavior of iron ore pellets containing carbon under non-isothermal condition in the temperature range from 573 to 1373K has been investigated in a laboratory scale setup. The test results show that carbon content has no obvious effect on reduction degree of composite pellets (C/O mole ratio=1.0) by CO in the temperature range from 575 to 1373K under linear temperature-rising program; reduction degree of iron ore pellets containing carbon is larger in 90%CO-10%CO2 mixture than that of in 100%CO atmosphere or in 80%CO-20%CO2 mixture; the s type temperature-rising program has a better effect than that of linear one to increase the reduction degree; and reduction degree of slower linear temperature-rising program is greater than that of faster one, but the final reduction degrees, i.e., those at the highest temperature are about same for various CO partial pressures or temperature-rising programs. The kinetic analysis also shows that the reduction of iron ore-carbon composite pellets by CO or CO-CO2 mixture under non-isothermal condition should be controlled 6y surface reaction, and the apparent reduction activation energy changes with the reduction progress under various test conditions.
关键词:
iron ore pellet containing carbon
,
null
,
null
,
null
,
null
梁晨
,
李家新
,
龙红明
,
王平
,
解成成
钢铁研究学报
doi:10.13228/j.boyuan.issn1001-0963.20140426
为了提高含碳球团强度,提出了内层为含碳球团,外层为精矿粉的双层结构复合含碳球团新工艺.研究了不同外层厚度球团的强度和金属化率,分析了球团强度形成的机理.研究结果表明:外层厚度适中的复合含碳球团强度能得到有效提高.该复合球团生球落下强度为普通含碳球团的2倍,400℃预热球抗压强度可达147.6N/个.900℃后,随着温度的增加,球团抗压强度提高,1150℃恒温还原30 min后抗压强度为2 080 N/个.且研究发现复合含碳球团能有效提高碳素利用率,C/O物质的量之比nC/nO为2∶3的复合球团还原后金属化率可达93.90％,其中外层金属化率为92.46％.通过显微结构分析,发现球团还原后外层生成了致密的金属铁外壳,这种外壳的独特力学性能是球团强度提高的主要原因.
关键词:
含碳球团
,
抗压强度
,
双层结构
,
金属化率
魏汝飞
,
李家新
,
龙红明
,
王平
,
施思强
钢铁
通过负荷还原试验,在温度为分别为1173,1 273和1373K,负荷为0.1 MPa,N2流量为1.0 L/min条件下对含碳球团还原过程的粘接行为进行了研究,并且对粘结临界状态进行了明确界定,对粘结指数的测定方法进行了改进.研究表明,含碳球团在还原过程中出现粘接现象,温度是影响粘结的重要因素,温度越高,粘接越严重,1373K时,含碳球团的粘结指数达到88.7％,粘结指数能够客观地反映出含碳球团在还原过程中的粘接情况,铁连晶和氧化亚铁连晶生长出界造成含碳球团的粘接,温度的升高,铁链晶和氧化亚铁连晶长大速度变大,使连晶生长出界的可能性变大,球团粘接变得严重.
关键词:
粘接行为
,
粘结指数
,
含碳球团
