(中南大學(xué) 資源加工與生物工程學(xué)院，長沙 410083)
摘 要: 采用鈉鹽添加劑強(qiáng)化紅土鎳礦的還原焙燒−磁選，確定了添加劑存在下適宜的焙燒和磁選技術(shù)參數(shù)，開發(fā)出紅土鎳礦還原焙燒−磁選制取鎳鐵合金原料的新工藝。結(jié)果表明：鈉鹽添加劑具有顯著降低焙燒溫度、大幅提高產(chǎn)品鎳、鐵品位和回收率的作用；對一種含鎳1.58%、鐵22.06%的紅土鎳礦配加添加劑后，在還原溫度1 100 ℃、還原時間60 min、磁場強(qiáng)度0.1 T的條件下，磁性產(chǎn)品的鎳、鐵品位可分別從無添加劑時的2.0%、57.2% 提高到 7.5%、80.5%，鎳、鐵回收率也相應(yīng)從19.1%、33.6% 增加到82.7%、62.8%。XRD結(jié)果表明：紅土鎳礦在無添加劑作用下經(jīng)還原焙燒−磁選所得的磁性產(chǎn)物中仍有部分鎂橄欖石及頑火輝石存在；而有添加劑存在時，還原生成的鎳鐵合金通過磁選可與非磁性脈石成分得到更為有效的分離，產(chǎn)品可作為不銹鋼的生產(chǎn)原料。
關(guān)鍵字: 紅土鎳礦；添加劑；還原焙燒；鎳鐵；不銹鋼
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
