Phase Transformation of Limonite Nickel Ores with Na2SO4 Addition in Selective Reduction Process

4th International Conference on Advanced Materials Science and Technology

Mayangsari, W.^1 ; Prasetyo, A.B.^1

Research Center for Metallurgy and Material, Indonesian Institute of Sciences, South Tangerang, Banten, Indonesia^1

关键词: Crystalline water;    Limonite;    Muffle furnaces;    Na2SO4;    Reduction temperatures;    Selective reduction;    Silica content;    Thermo-gravimetric;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/202/1/012016/pdf
DOI  :  10.1088/1757-899X/202/1/012016

来源: IOP

【 摘 要 】

This study aims to observe the transformations, both mineralogy and morphology of limonite nickel ore with coal as reducing agent and Na2SO4as an additive in the selective reduction processes. A series of selective reduction processes were carried out at various temperatures in Carbolite muffle furnace for 1 hour. The range of reduction temperature was determined from Thermogravimetric-Derivative Thermal Analysis (TG-DTA). The mineralogy of raw and reduced ores was characterized by using XRD analysis. The morphology, particle size, and mapping were characterized by using SEM-EDS analysis. The results showed that goethite was the main component in the raw limonite nickel ore and it was decomposed by losing the crystalline water at 300 °C. The decompositions were continued to lizardite and trevorite at 600 °C and 800 °C respectively, then Fe and Fe-Ni were formed at 900 °C. Metallization continuously occurred by increasing reduction temperature up to 1100 °C. Moreover, the particle size and porosity of reduced ore were greater up to 2.5-times. The addition of Na2SO4on the selective reduction processes decreased silica content; it also caused the formation of fayalite and FeS at 600 °C and 800 °C respectively. The intensity of fayalite and FeS decreased when the reduction temperature was more than 900 °C.