电石渣代替氧化钙对镍渣深度还原提铁的影响

Effect of carbide slag as additive on recovering iron by deep reduction process of nickel slag

采用深度还原法处理镍渣,以电石渣或氧化钙作单一添加剂,通过X射线衍射(XRD)、扫描电子显微镜(SEM)和能谱(EDS)等方法,对比分析了两种添加剂分别作用时所得还原产物中的物相和微观结构特征。结果表明,以电石渣代替氧化钙作单一添加剂进行镍渣深度还原提铁是可行的;两者所得金属精选粉的铁指标变化趋势基本一致,所得还原产物的物相组成基本相同,但微观结构存在差异;电石渣作添加剂时,还原产物内部的金属相成片连接,内部气孔形态不规则,气孔表面形成更密集的金属相层,生成的金属相向气孔表面迁移富集趋势较使用氧化钙时更显著;电石渣作添加剂在二元碱度1.0时,所得金属精选粉的铁品位、铁回收率和铁金属化率分别为91.07%、91.20%和92.35%。

A nickel slag was processed by the deep reduction method with carbide slag and calcium oxide as single additive,respectively.The phase composition and microstructure of the reduction products obtained using the different additives were comparatively investigated by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM） and energy dispersive spectrometry（ EDS） analysis. The results show that it is feasible to utilize carbide slag as the additive replacement of calcium oxide for recovering iron from nickel slag by deep reduction,and their change tendency of iron indexes about the metallic concentrate powders are consistent basically,and their phase composition of the reduction products is same mostly,but their microstructure of reduction products is different obviously. At binary basicity ratio of 1. 0and with carbide slag as additive,the grade,recovery rate and metallization rate of iron for the obtained metal concentrate powders are91. 07% 、91. 20% and 92. 35%,respectively.