(中南大学 资源加工与生物工程学院，长沙 410083)
摘 要: 采用钠盐添加剂强化红土镍矿的还原焙烧−磁选，确定了添加剂存在下适宜的焙烧和磁选技术参数，开发出红土镍矿还原焙烧−磁选制取镍铁合金原料的新工艺。结果表明：钠盐添加剂具有显著降低焙烧温度、大幅提高产品镍、铁品位和回收率的作用；对一种含镍1.58%、铁22.06%的红土镍矿配加添加剂后，在还原温度1 100 ℃、还原时间60 min、磁场强度0.1 T的条件下，磁性产品的镍、铁品位可分别从无添加剂时的2.0%、57.2% 提高到 7.5%、80.5%，镍、铁回收率也相应从19.1%、33.6% 增加到82.7%、62.8%。XRD结果表明：红土镍矿在无添加剂作用下经还原焙烧−磁选所得的磁性产物中仍有部分镁橄榄石及顽火辉石存在；而有添加剂存在时，还原生成的镍铁合金通过磁选可与非磁性脉石成分得到更为有效的分离，产品可作为不锈钢的生产原料。
关键字: 红土镍矿；添加剂；还原焙烧；镍铁；不锈钢
laterite ore by reduction roasting-magnetic separation
（School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, China）
Abstract:An innovative process for preparing ferronickel materials from laterite ore by reduction roasting-magnetic separation in the presence of additives was proposed, and the effect of additives on reducing roasting-magnetic separation of laterite ore and the technical parameters of roasting and magnetic separation were investigated. The results show that the sodium salt additives are not only able to dramatically decrease the reducing temperature, but also increase the grades and recoveries of nickel and iron in ferronickel. The grades of nickel and iron are improved from 2.0% and 57.2% to 7.5% and 80.5%, respectively, and also the recoveries of nickel and iron are improved from 19.1% and 33.6% to 82.7% and 62.8%, respectively, as the addition of additives is under the conditions of reduction temperature 1 100 ℃, reduction time 60 min, magnetic field intensity of 0.1 T. The ferronickel materials obtained can be used for the stainless steel production as the XRD results show that the magnetic product is mainly comprised of ferronickel in the presence of additives, while still contains a portion of forsterite and enstatite in the absence of additives.
Key words: laterite; additives; reduction roasting; ferronickel; stainless steel
