高镁贫镍红土矿煤基还原制备镍铁合金

Preparation of Ferro-Nickel Alloy from High Magnesium Low Nickel Laterite Ore in Coal-based Direct Reduction Smelting Process

以含Ni 0.82%、含MgO 31.49%的高镁贫镍红土矿为原料,采用煤基直接还原熔炼方法制备镍含量高于7%的镍铁合金,对产物进行了表征,通过正交实验确定了最优工艺条件.结果表明,原矿主要由蛇纹石、石英和氧化镁组成,81.49%的镍元素取代镁或以吸附态分布于蛇纹石中.温度高于1500℃熔炼过程才能顺利进行.通过L9（3^3）正交实验确定的最优工艺条件为：熔炼温度1600℃,配碳比C/O=2.0,焙烧时间45 min.该条件下制备出了镍品位7.19%、镍铁含量84.23%的球状镍铁合金,Ni回收率为82%.

The high magnesium（31.49% Mg O）, low nickel（0.82% Ni） laterite ore was used to extract the high grade ferro-nickel alloy by the coal-based direct reduction method. The product was analyzed, the optimal conditions were obtained by orthogonal experiments. The results showed that the content of Ni in the ferro-nickel alloy is more than 7%. The laterite ore mainly consists of serpentine, quartz and magnesium oxide phases. In addition, 81.49% Ni within raw ore is distributed in serpentine, by substitution for Mg and/or by adsorption. Smelting could be occurred completely when the roasting temperature above 1 500 ℃. The orthogonal experiments L9（3^3） were carried out to obtain the optimum technological parameters. A ferro-nickel alloy, which contains 7.19% Ni, 84.23% ferro-nickel can be obtained at the roasting temperature 1 600 ℃ for 45 min, with atomic ratio C/O 2.0, the recovery rate of nickel is 82%.