表征铁矿粉烧结液相流动性能的新方法

为了弥补传统评价铁矿粉烧结液相流动性能指标不考虑液相流动速度、温度及升温速率或不考虑温度对液相流动速度影响的不足和采用多个指标分开来表征液相流动速度与温度所带来的使用上的不便.利用可视卧式高温炉观测铁矿粉试样的熔化流动过程,结合试验中试样收缩与流动规律定义了烧结液相流动始末点,并提取重要参数指标:流动温度、流动时间、面积增长率和升温速率;给出了定量表征温度对烧结液相流动速度影响的函数关系式v(T);在此基础上建立了以实际烧结生产温度为基准,包含流动过程各种关键信息及其内涵的流动性特征数(LD).对比2种方法得到的结果,发现采用流动性特征数可以进一步区分出不同铁矿粉的流动性差异,提高了表征精度,从而为评价铁矿粉流动性能提供了可靠的参考依据.

A new characterization method for the liquid phase fluidity of iron ore powder during sintering

In order to make up for the deficiency of traditional evaluation indexes which does not consider the liquid flow rate, temperature and heating rate or the effects of temperature on the liquid flow rate and the inconvenience for using multiple indexes to express the characterization of liquid flow rate and temperature??a visible horizontal high temperature furnace was employed to observe the melting process of iron ore powder samples, with the combination of shrinkage and flowing phenomenon of the sample, the beginning and ending point of liquid phase flowing was defined, and several important parameters including flowing temperature, flowing time, increasing rate of area and heating rate were extracted. Besides, the functional relationship formula v(T) between temperature and liquid phase flowing speed was quantitatively given. Based on this, the fluidity characteristics number (LD), taking the actual sintering temperature as the reference temperature, was established and it includes the key information and the internal relation of corresponding parameters. Comparing the results of the two methods, the new index can further distinguish the differences among different iron ore powders in fluidity thus improve the precision of characterization, which provides a reliable reference for evaluating the flowing properties of iron ore powder.