超细赤铁矿粉非熔态还原实验研究

研究了平均粒度为2μm的超细赤铁矿粉和粒度分布为0.18～0.154mm的常规细矿粉在非熔态下的还原情况.以矿粉的还原度为目标,用改造后的L₁₆(2¹⁵)正交表安排4×2³次试验,以排除还原气氛、还原温度和还原时间等因素的干扰.结果表明,在纯H₂、100%CO两种气氛下,温度为650～850℃时,均能实现不同程度Fe₂O₃→Fe的还原,与常规粒度矿粉相比,超细矿粉的还原度较高,获得相同还原度时所需的还原温度约低365℃.试验中,各因子之间均无相关性,可分别估计其定量的影响,建立线性回归式.超细赤铁矿粉非熔态还原后的粒度分布观察表明,颗粒间并未发生烧结,还原产物仍为粉状.

Experimental study on reduction of ultra-fine hematite powder at non-molten state

The reduction degrees of ultra-fine hematite powder(the average particle size is 2μm) and conventional hematite powder(the range of particle size is 0.18 to 0.154mm) in non-molten process were studied.Taking the reduction degree of hematite powder as a target and according to the transformed L₁₆(2¹⁵) orthogonal table,a series of 4×2³ times experiments were arranged to eliminate the interference of reduction atmosphere,reduction temperature and reduction time.The results show that ultra-fine hematite powder can be reduced from Fe₂O₃ to Fe at different degrees.Compared with conventional particle size hematite powder,ultra-fine hematite powder has a higher reduction degree,and the reduction temperature required to access the same reduction degree lowers about 365 ℃ under the condition of 650 to 850 ℃ and pure H₂ or 100% CO atmosphere.There is no correlation among these factors,the quantitative impact of them can be separately estimated,and this provides a basis for establishing an equation of linear regression for each of them.After reduction at non-molten state,the particle size distribution of hematite powder indicates that inter-particle sintering does not occur and the reduction product is still powdery.