Feasibility of co-reduction roasting of a saprolitic laterite ore and waste red mud

• Published in: International journal of minerals, metallurgy and materials metallurgy and materials, 2018-06, Vol.25 (6), p.591-597
• Main Authors: Wang, Xiao-ping, Sun, Ti-chang, Kou, Jue, Li, Zhao-chun, Tian, Yu
• Format: Article
• Language: English
• Subjects: Ceramics; Characterization and Evaluation of Materials; Chemical composition; Chemistry and Materials Science; Composites; Corrosion and Coatings; Direct reduced iron; Feasibility; Ferronickel; Glass; Grain growth; Iron ores; Laterites; Liquid phases; Magnetic separation; Materials Science; Metallic Materials; Mud; Natural Materials; Nickel; Recovery; Red mud; Roasting; Silicon dioxide; Surfaces and Interfaces; Thin Films; Tribology; X-ray diffraction
• ISSN: 1674-4799; 1869-103X
• DOI: 10.1007/s12613-018-1606-7

Large scale utilization is still an urgent problem for waste red mud with a high content of alkaline metal component in the future. Laterite ores especially the saprolitic laterite ore are one refractory nickel resource, the nickel and iron of which can be effectively recovered by direct reduction and magnetic separation. Alkaline metal salts were usually added to enhance reduction of laterite ores. The feasibility of co-reduction roasting of a saprolitic laterite ore and red mud was investigated. Results show that the red mud addition promoted the reduction of the saprolitic laterite ore and the iron ores in the red mud were co-reduced and recovered. By adding 35wt% red mud, the nickel grade and recovery were 4.90wt% and 95.25wt%, and the corresponding iron grade and total recovery were 71.00wt% and 93.77wt%, respectively. The X-ray diffraction (XRD), scanning electron microscopy, and energy dispersive spectroscopy (SEM-EDS) analysis results revealed that red mud addition was helpful to increase the liquid phase and ferronickel grain growth. The chemical compositions “CaO and Na 2 O” in the red mud replaced FeO to react with SiO 2 and MgSiO 3 to form augite.