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黄金玉,胡明伟,窦安南,等. 工艺因素对铁矿粉流态化还原效果影响机理的模拟研究[J]. 安徽工业大学学报(自然科学版),xxxx,x(x):x-xx. doi: 10.12415/j.issn.1671-7872.24009
引用本文: 黄金玉,胡明伟,窦安南,等. 工艺因素对铁矿粉流态化还原效果影响机理的模拟研究[J]. 安徽工业大学学报(自然科学版),xxxx,x(x):x-xx. doi: 10.12415/j.issn.1671-7872.24009
HUANG Jinyu, HU Mingwei, DOU Annan, ZHU Guoming, XU Qiyan. Simulation Study on Influence Mechanism of Process Factors on the Fluidized Reduction Effect of Iron Ore Powder[J]. Journal of Anhui University of Technology(Natural Science). DOI: 10.12415/j.issn.1671-7872.24009
Citation: HUANG Jinyu, HU Mingwei, DOU Annan, ZHU Guoming, XU Qiyan. Simulation Study on Influence Mechanism of Process Factors on the Fluidized Reduction Effect of Iron Ore Powder[J]. Journal of Anhui University of Technology(Natural Science). DOI: 10.12415/j.issn.1671-7872.24009

工艺因素对铁矿粉流态化还原效果影响机理的模拟研究

Simulation Study on Influence Mechanism of Process Factors on the Fluidized Reduction Effect of Iron Ore Powder

  • 摘要: 以高压循环流化床为原型,建立流化床内管几何模型,综合考虑颗粒间传热传质和化学反应特征,以金属化率和反应平衡时间为评价指标,采用Barracuda软件模拟分析还原温度、矿粉粒径、还原气氛等工艺因素对铁矿粉流态化还原的影响,确定铁矿粉流态化还原的最佳方案;采用扫描电镜表征矿粉微观形貌,探讨工艺因素对铁矿粉流态化还原和黏结机理。结果表明:矿粉粒径为0.150,0.180) mm时,还原温度在573 ~1 173 K范围内,升高温度有利于提高铁矿粉的金属化率和颗粒纵向速度,缩短反应平衡时间,温度过高颗粒纵向速度降低,这是由于铁晶须相互勾连形成团聚,抑制矿粉流化;温度为973 K时,矿粉粒径在0.080,1.000) mm范围内,减小粒径可增大铁矿粉的比表面积,利于提高铁矿粉的金属化率,矿粉粒径过小会使颗粒堆积不易流化;还原气氛为(H2+CO)的条件下,纯H2的还原效率优于CO,但CO的体积比增加可减少水蒸气生成,有利于提高矿粉的流化性能。气体线速度为0.6 m/s、压力为0.2 MPa条件下,流态化还原铁矿粉的最佳工艺参数为还原温度973 K、粒径0.150,0.180) mm、还原气氛70%H2+30% CO。

     

    Abstract: Taking the high-pressure circulating fluidized bed as a prototype, the geometric model of the tube inside the fluidized bed was established, the inter-particle heat and mass transfer and chemical reaction characteristics were taken into account, and the metallization rate and reaction equilibrium time were taken as the evaluation indexes, and the Barracuda software was used to simulate and analyze the effects of the process factors, such as the reduction temperature, the particle size of the ore powder, and the reduction atmosphere, on the fluidized reduction of iron ore powder, to determine the optimal scheme for the fluidized reduction of iron ore powder. Scanning electron microscope (SEM) was used to characterize the micro-morphology of the ore powder, and to explore the influence of process factors on the fluidized reduction of iron ore powder and the bonding mechanism. The results show that when the particle size of mineral powder is 0.150, 0.180) mm, the reduction temperature is in the range of 573–1 173 K. Increasing the temperature is beneficial for improving the metallization rate and the longitudinal velocity of the particles and shortening the reaction equilibrium time. If the temperature is too high, the longitudinal velocity of the particles decreases, This is because the iron whiskers are interconnected and form agglomerations, which inhibits the fluidization of the iron ore powder.When the temperature is 973 K, the particle size of the ore powder is in the range of 0.080,1.000) mm. Decreasing the particle size can increase the surface area, which is beneficial for improving the metallization rate of iron ore powder. If the particle size is too small, it will make it difficult for the particles to accumulate and fluidize,Under the condition of reducing the atmosphere to H2 + CO , the reduction efficiency of pure H2 is better than that of CO. However, increasing the volume ratio of CO can reduce the generation of water vapor, which is beneficial for improving the fluidization performance of mineral powder. The optimum process parameters for fluidized reduction of iron ore powder are reduction temperature of 973 K, particle size of 0.150,0.180) mm, and reduction atmosphere of 70% H2 + 30% CO under the condition of gas linear velocity of 0.6 m/s and pressure of 0.2 MPa.

     

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