氯化钙作用下镁质贫镍红土矿选择性富集镍的研究

采用还原焙烧-磁选工艺, 对氯化钙作用下镁质贫镍红土矿选择性富集镍进行了研究, 考察了还原温度、还原时间、还原剂用量和氯化钙用量对富集镍的影响。结果表明, 在还原温度1 200 ℃、还原时间40 min、还原剂和氯化钙用量均为8%的条件下, 可获得镍品位8.67%、回收率92.01%的镍铁精矿; 相比于直接还原焙烧-磁选, 加入8%氯化钙后使镍的富集比由3增加到11, 显著提高了镍的富集效果。磁选产品物相分析显示, 镍主要以铁纹石形式存在于精矿中, 通过磁选实现了对镍铁精矿与脉石的有效分离。

Selective Enrichment of Nickel from Low-Ni and Mg-rich Laterite Ore in the Presence of Calcium Chloride

The selective enrichment of nickel from low-nickel magnesium-rich laterite ore was studied by adopting a process consisting of reduction roasting and magnetic separation, and effects of reduction temperature, reduction time, reductant dosage and calcium chloride dosage on enrichment of nickel were investigated. Results showed that the ore reduced at 1 200 ℃ for 40 min in the presence of 8% reductant and calcium chloride, resulted in 92.01% recovery to a ferronickel concentrate grading 8.67% Ni. Compared with the process of reduction without calcium chloride, an addition of 8% calcium chloride increased the enrichment ratio of nickel from 3 to 11, indicating a significant improvement. The phase analysis of product after magnetic separation indicated that nickel primarily exists in the form of kamacite in the concentrate, and the separation between ferronickel concentrate and gangue can be actualized by magnetic separation.