关键词: 红土镍矿, 碱度, 还原焙烧, 弱磁选, 镍铁合金

Abstract: The grate-kiln DR process for the reduction of laterite pellets requires high temperature，which brings about problems such as higher demand of refractory material and poor reducing performance.In order to develop a more efficient process with low cost，the effect of basicity was studied by addition CaO as flux in the pellets.Experimental results show that at reduction temperature 1 400 ℃ for 60 min and the roasted products via grinding-low intensity magnetic separation on natural basicity laterite，the magnetic products with nickel and iron grade of only 3.8% and 72.9%，nickel and iron recovery of 17.8% and 39.8% were obtained，there are much magnesium olivine and enstatite in magnetic products; the fusion temperature of laterite ore could be decreased by 100 ℃ by adjusting the basicity to 1.0，compared with natural basicity; at reduction temperature 1 300 ℃ for 60 min with basicity of 1.0，and the roasted products via grinding-low intensity magnetic separation，the magnetic products with nickel and iron grade of 8.7% and 83.8%，nickel and iron recovery of 85.6% and 62.8% were obtained.The XRD patterns and scanning electron microscope shown that the Fe-Ni particles generated during the reducing of laterite ore with natural basicity distributed dispersedly and the size was generally below 5 μm.What's more，forsterite and enstatite was found in the magnetic material.With the basicity increased to 1.0 through adding CaO，the size of Fe-Ni particles grown to 10~50 μm，and few impurities could be found in the magnetic product.The experimental results could provide fundamental basis for the novel process for preparation of ferronickel from laterite pellets by reduction roasting.

Key words: Nickel Laterite, Basicity, Reduction roasting, Low intensity magnetic separation, Ferronickel alloy