Study On Coal-based Reduction Of Lateritic Nickel Ore

Nickel is a type of widely used metal.Nickel is of the superities in anti-oxidation,anti-corrosion,withstanding high temperature,high strength and highly ductility.Nickel is mainly consumed in the areas of Steel-making and nonferrous alloy,also consumed in the areas of light industry,machinofacture,chemical industry,oil industry and power industry.With technique evolution nickel is also widely used in high-tech areas.The global nickel reserve is 160 million ton,forty percents of the reserves is in the form of sulfride ore.The nickel used in the world wide is seventy percents from such sulfride ore.With the high rised requirement of nickel,the technique to produce nickel from siliceous nickel ore,laterite,is earning much interest.This paper stated the study on coal based reduction-magnetic separation to produce nickel ferrous from laterite.XRD(X-ray diffraction)result indicated that the main Ni-contained minerals are Nepouite(Ni,Mg)3Si4O10(OH)2 and Willemseite Ni3Si2O5(OH)4,main Fe-contained minerals are Lizardite(Fe,Mg)3Si2O5(OH)2 and ferripyrophilite Fe3Si4O10(OH)2.The optimum of the batch in weight is Laterite:Agent:Reductant= 40:8:3.The optimum experimental parameters were 1200? for 2h,the fine concentrate of 200 mesh and 222.88kA/m of magnetic field intensity.The optimum Ni,Fe recovery rate and concentrate grades were gotten under such parameters,90%,93%of Ni,Fe recovery rate and 14%?59%of concentrate grade corresponding to Ni,Fe.Several types coal were used in the study,the results indicated that the best batch is composed of laterite:additive:anthracite=80:16:12(in weight).The Ni,Fe recovery were83.07%,71.66%?XRD analysis indicated that Willemseite Ni3Si2O5(OH)4 separated to Ni3Si2O7(amphous)and H2O at the temperature of 600?.With temperature rising,Ni3Si2O7 separated into Ni2Si2O4.Thermaldynamic analysis indicated that,the main reductive was solid carbon in Ni,Fe reduction process.SEM analysis indicated that the metal Ni,Fe reduced from laterite was in the form of alloy.