在自制的kg级高温流化床中研究了氢气还原1～3mm矿粉的动力学试验.随着时间的增加,气体利用率下降,表明还原前期反应速度快,后期反应慢;温度越高,气体利用率越高,但随着还原时间的增加,差距在逐步缩小;对于750℃,前20min的气体利用率为9%,金属化率达到84%,说明氢气还原矿粉反应是非常迅速的.随着气速的增加,金属化率在增加,并且几乎成线性关系,因此使用氢气作为还原剂,可以允许更高的气速,从而提高设备的生产效率.随着料高的增加,金属化率不断下降,然而气体利用率却在不断升高.使用氢气作为还原剂,可以将还原温度降低到700～750℃,避免流化床过程中的粘结难题;试验中氢气还原1～3mm铁矿粉时的表观活化能为58.4 kJ/mol.
Kinetics experiment was conducted in a self-prepared kg-scale high temperature fluidized bed for 1-3 mm ore fines reduction with hydrogen. The utilization rate of hydrogen decreases with reaction, which shows that the reactive speed is fast in the early reaction stage, but afterwards slower. The higher the reaction temperature, the more the utilization rate of hydrogen, but difference of the utilization rate is narrowed gradually with the increase in reaction time. Under the conditions of the first 20 min and 750℃, the utilization rate of hydrogen is 9%, and the metallization degree reaches 84%, which shows that the speed of reduction reaction with hydrogen is very fast. With increase in hydrogen gas velocity, the metallization degree of iron ore fines increases linearly. So, in order to im-prove the productivity of facility, in case of hydrogen as reducing gas, much higher velocity of hydrogen can be al-lowed. With increase in the bed depth, metallization degree of iron ore fines decreases while the utilization rate of hydrogen increases gradually. The reaction temperature can lower to 700-750 ℃ with hydrogen as reducing gas, which is helpful to solve the sticking problems of fluidized bed. As for the reduction reaction of 1-3 mm iron ore fine swith hydrogen, its apparent activation energy is about 58.4 kJ/mol in the fluidized bed experiment.
参考文献
| [1] | Fruehan R J;Li Y;Brabie L .Final Stage of Reduction of Iron Ores by Hydrogen[J].Scandinavian Journal of Metallurgy,2005,34:205. |
| [2] | El-geassy A A;Nasr M I .Influence of Original Structure on the Kinetics and Mechanisms of Carbon Monoxide Reduction of Hematite Compacts[J].ISIJ International,1990,30(06):417. |
| [3] | Sujoy K dutta;Ahindra ghosh .Kinetics of Gaseous Reduction of Iron Ore Fines[J].ISIJ International,1993,33(11):1168. |
| [4] | Pourghahramani P;Forssberg E .Reduction kinetics of mechanically activated hematite concentrate with hydrogen gas using nonisothermal methods[J].Thermochimica Acta: An International Journal Concerned with the Broader Aspects of Thermochemistry and Its Applications to Chemical Problems,2007(2):69-77. |
| [5] | Pineau A;Kanari N;Gaballah I .Kinetics of reduction of iron oxides by H-2 - Part I: Low temperature reduction of hematite[J].Thermochimica Acta: An International Journal Concerned with the Broader Aspects of Thermochemistry and Its Applications to Chemical Problems,2006(1):89-100. |
| [6] | Unal A;Bradshaw A V .Rate Processes and Structural Changes in Gaseous Reduction of Hematite Particles to Magnetit[J].Metallurgical and Materials Transactions B:Process Metallurgy and Materials Processing Science,1983,14B(12):743. |
| [7] | Farren M;Matthew S P;Hayes P C .Reduction of Solid Wustite in H_2/H_2O/CO/CO_2 Gas Mixtures[J].Metallurgical and Materials Transactions B:Process Metallurgy and Materials Processing Science,1990,21B(02):135. |
| [8] | R.A.D. Rodriguez;A.N. Conejo;E.B. Bedolla .Kinetics of Reduction of Fe_2O_3 Particles with H_2-CO Mixtures at Low Temperatures[J].Iron & Steelmaker,2003(1):25-33. |
| [9] | 赵沛,郭培民,张殿伟.低温非平衡条件下氧化铁还原顺序研究[J].钢铁,2006(08):12-15. |
| [10] | 赵沛,郭培民.纳米冶金技术的研究及前景[C].2005中国钢铁年会论文集,2005:677-681. |
| [11] | 赵沛,郭培民.利用粉体纳米晶化促进低温冶金反应的研究[J].钢铁,2005(06):6-9. |
| [12] | 庞建明,郭培民,赵沛,曹朝真,张殿伟.低温下氢气还原氧化铁的动力学研究[J].钢铁,2008(07):7-11. |
| [13] | 郭培民,张殿伟,赵沛.氧化铁还原率及金属化率的测量新方法[J].光谱学与光谱分析,2007(04):816-818. |
| [14] | 华一新.冶金过程动力学导论[M].北京:冶金工业出版社,2004 |
| [15] | 刘建华,张家芸,周土平.CO及CO-H2气体还原铁氧化物反应表观活化能的评估[J].钢铁研究学报,2000(01):5-9. |
| [16] | 刘建华;张家芸;周土平 .氢气还原铁氧化物反应表观活化能的评估[J].钢铁研究学报,1999,11(06):9. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%