Laterite ore properties and their influence mechanism on direct reduction roasting

Two types of nickel laterite ores were chosen as the object of study. Optical microscopy, scanning electron microscopy and X-ray diffraction were used to analyze the similarity and difference between the two ores. Both the ores were beneficiated by a selective reduction roasting-magnetic separation method for studying the influence of ore properties on direct reduction roasting. It is found that the main minerals, nickel-bearing minerals and nickel distribution are very similar in the two ores. But due to the difference in content of iron, silicon and magnesium, the beneficiation results using the selective reduction roasting- magnetic separation are quite different. This is probably the reason that in the roasting process, iron, magnesium and calcium cations react with silicate anions to form different silicates, affecting the melting properties of roasting ores and the reactivity of nickel.