深度还原工艺对铁颗粒粒度影响规律研究

采用深度还原技术处理浸染微细粒度的复杂难选铁矿石,控制铁颗粒粒度是分选出合格产品的关键.根据深度还原物料中铁颗粒的球形特征,通过测量铁颗粒二维截面参数,求取了其累计粒度特性曲线,定性地描述了不同深度还原工艺对铁颗粒粒度的影响规律.结果表明:适当的提高还原温度、延长还原时间、增大配碳系数,都有利于铁颗粒的长大,但还原温度过高、配碳系数过大将阻碍铁颗粒长大;适宜的工艺条件为:还原温度1 225℃,还原时间30min,配碳系数2.0,获得铁颗粒的d50为278.88μm.

Effect of reduction process on size of iron grain

When reduction technology is used for the fine-grained refractory iron ore,it is the key to control iron grain size in order to obtain qualified separation product.As the iron grains from the reduction materials were spherical,the effects of different reduction processes on iron particles were qualitatively described by measuring the two-dimensional cross-section parameters of iron grains for the accumulative characteristic curve.The results indicate that properly increasing the reduction temperature and time,extending the coefficient of carbon,were conducive to the iron particles to grow up.However,when reduction temperature with a coefficient of carbon was exorbitant high,the reduction temperature would prevent the growth of iron particles.The suitable process conditions of reducing temperature of 1 225 ℃,reducing time of 30 min,distribution coefficient of carbon of 2.0 were achieved.The d50 of iron particles of 278.88 μm was obtained.