During an experiment of fluidized-bed reduction of Brazil iron ore powder, effects of temperature, particle size, hydrogen content and linear velocity of gas on the metallization rate, as well as the bonding mechanism of ore powder were investigated. The primary and secondary factors affecting the metallization rate were studied by using range analysis and comprehensive equilibrium analysis. Energy spectrum analysis was then conducted for the defluidized ore samples. Results show that temperature is the predominant factor influencing the metallization rate. At an temperature of 750 ℃, with particle size within the range of 0.149~0.425 mm, hydrogen content at 80%, linear velocity of gas at 0.3 m/ s (neglecting blowing loss), the metallization rate reached 82%. And during the reduction process, the higher the metallization rate, the lower the pressure difference of fluidized-bed. With the particle size less than 0. 149 mm, defluidization occurred after process ran for 15 minutes. It is concluded that ore powder with medium size range can have a longer fluidization time.%研究了巴西矿粉流态化还原实验中温度、颗粒粒径、富氢含量和气体线速度等因素对金属化率的影响,并分析了矿粉粘结机理.采用极差分析法和综合平衡分析法研究了影响金属化率的主次因素,并对发生失流的试样进行了能谱分析.结果表明,温度是影响金属化率的主要因素;750℃ 、颗粒粒径0.149~0.425 mm、氢气含量80%、气体线速度0.3 m/s(不考虑吹损)时,金属化率达到82%;还原过程中,金属化率越高,床层压差越小.当粒度小于0.149 mm时,15 min开始出现失流,中等粒度的矿粉能保持较长的流化时间.
展开▼
