镍渣煤基直接还原过程中金属铁颗粒的生长特性  

Particle growth characteristics of metallic iron in direct coal-based reduction of nickel slag

作　　者：李小明[1] 李怡 邢相栋[1] LI Xiao-ming;LI Yi;XING Xiang-dong(School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,Shaanxi,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055

出　　处：《钢铁》2020年第3期104-109,共6页Iron and Steel

基　　金：国家自然科学基金资助项目(51774224)。

摘　　要：镍渣煤基直接还原可有效利用其中的二次资源。定量描述不同条件下镍渣煤基直接还原过程中金属铁颗粒的生长特性及规律,为后续磨矿及磁选工艺的制定提供理论支撑,以此来达到镍渣资源化利用的目的。采用扫描电镜获得还原产物中金属铁颗粒的微观形貌,通过Image-Pro Plus图像分析软件对扫描图片进行金属铁颗粒尺寸测量统计,并对还原后样品进行金属化率检测。结果表明,煤基直接还原技术能够有效还原镍渣中的铁氧化物,产物的金属化率呈先增长后稳定的变化趋势,温度为1250℃、时间为60min时,金属化率最终可达91.89%;随着还原时间的延长及还原温度的升高,镍渣还原产物中金属铁颗粒的聚集和生长加快,颗粒的平均直径逐渐变大;还原温度为1250℃,还原时间为60min时,金属铁颗粒的平均直径可增长到10.3μm。The secondary resources in nickel slag can be effectively utilized by direct coal-based reduction.The growth characteristics and rules of metallic iron particles during the direct coal-based reduction of nickel slag under different conditions was described quantitatively,providing theoretical support for the development of subsequent grinding and magnetic separation processes,so as to achieve the purpose of efficient resource utilization of nickel slag.The microstructure of iron particles was observed by the scanning electron microscope.Image-Pro Plus Image analysis software was used to detect and analyze the size of metallic iron particles.The metallization rate of the reduced samples was measured.The results indicate that the coal-based direct reduction technology can effectively reduce the iron resources in nickel slag;the metallization rate of products shows a trend of first increasing and then stabilizing,and finally reaches 91.89%at 1250℃and 60 min;the average size of metallic iron particles in the reduced samples of nickel slag increases with the increase of time and temperature,and the increase of temperature is beneficial to the aggregation and growth of metallic iron particles in nickel slag;the average size of iron particle in the reduced samples increases up to 10.3μm when the temperature is 1250℃and the reduction time is 60 min.

关 键 词：镍渣 直接还原 金属铁相 颗粒尺寸 生长特性 

分 类 号：TF55[冶金工程—钢铁冶金]