旋转床CO还原澳大利亚PB粉特性及动力学研究

采用自主研制的小型旋转床反应器,结合化学分析和X射线衍射分析等技术对CO还原澳大利亚PB粉进行了直接还原实验研究。结果表明:CO流量为200 mL/min,矿粉粒径范围为0.044~0.089 mm,还原时间为60 min,还原温度为1 000℃时,还原产物还原度和金属化率达到最大值,分别为92.70%和86.28%;在700~1 000℃内基于收缩未反应核模型对澳大利亚PB粉还原反应进行动力学分析,得出反应前期(t30 min)还原过程由气体内扩散和界面化学反应混合控制;反应后期(t30 min)还原反应的限制性环节为气体内扩散,指前因子A为0.006 72 s~(-1),表观活化能E为10.043 kJ/mol。

Study on characteristics and kinetics of Australian PB powder reduced by CO in rotary bed

The experimental study on the direct reduction of Australian PB powder by CO was carried out by using a self-developed small-scale rotating bed reactor combined with chemical analysis and X-ray diffraction analysis. The results show that when the CO flow rate is 200 mL/min,the particle size range is 0.044-0.089 mm,the reduc-tion time is 60 min,and the reduction temperature is 1000 ℃,the reduction rate and metallization rate of reduced product are 92.70% and 86.28%,respectively. Kinetic analysis for Australian PB powder reduction reaction was carried out based on the shrinking unreacted core model at 700-1000 ℃. It is concluded that the reduction process is controlled by the gas internal diffusion and interface chemical reaction in the initial stage (t<30 min),and the limiting step of reduction reaction is gas internal diffusion in the final stage(t>30 min)with the pre-exponential factor of A is 0.00672 s-1 and the apparent activation energy of E is 10.043 kJ/mol.