Reducibility of nickeliferous limonitic laterite ore from Central Anatolia

This study investigates the reduction of limonitic nickel laterite ore from the Sivrihisar reserve in Turkey, focusing on the effects of temperature and coal addition on nickel and cobalt metallisation. The objective was to determine how varying temperatures (700–1100°C) and coal percentages (5.74, 8.61, and 11.48 wt-%) under an argon atmosphere influence the metallisation processes. Methodologically, the run-of-mine ore and reduced samples were analyzed using X-ray diffraction to quantify the metallisation of iron (Fe), nickel (Ni), and cobalt (Co). Results indicated that the metallisation of Fe was limited up to 900°C but increased significantly at higher temperatures, especially at 1100°C. The metallisation of Ni and Co rose with temperature increases from 700 to 800°C, plateaued until 900°C, and continued to rise up to 1100°C. Interestingly, coal addition did not significantly impact Fe metallisation up to 900°C, while its effects were more noticeable at higher temperatures. The data suggest that increased coal addition consistently affected nickel reduction across all temperatures without influencing Co metallisation. This highlights the complex interactions between reduction conditions and the metallisation of key minerals in nickel laterites.