Study effect of carbon type in thermal upgrading of limonite Fathan Bahfie, Azwar Manaf, Widi Astuti, Fajar Nurjaman, Erik Prasetyo
1Research Center of Mining Technology, National Research and Innovation Agency of Indonesia
2Physics Department, Universitas Indonesia
Abstract
Thermal upgrading is the process for nickel extraction in selective reduction with holding temperature in low (300-500 oC). The effect and type of reductor are the main factor during this process. With those factors, this research will be finding the variation of reductor type. The first step is limonite and reductor characterization. Ni, Fe, Mg, Al, and Si levels in limonite are 1.4 Ni, 50.5 Fe, 1.81 Al, 4.86 Mg, and 16.5 Si weight percent, respectively. The iron oxide/oxyhydroxide content of limonite is 94.4 percent and 5.6 percent silicate. For reductor, those are graphite, palm kernel shell, and anthracite with carbon percentage 98, 77, and 68 %. From XRF, the optimum nickel grade is in the graphite and anthracite with 6.5 and 7 wt%. For phases, the ferronickel is appearing in the high intensity for the optimum reductor type and the microstructure is around 5-10 um for both. Moreover, the optimum reductor type are graphite and anthracite.
