BIOMASS TORREFACTION FOR COAL BLENDS AS SAPROLITE NICKEL ORE SMELTING REDUCTOR

• Main Author: Fadhila Qinthara, Hanif
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/74046
• Institution: Institut Teknologi Bandung

Indonesia is one of the largest nickel producer and exporter in western side of the earth. Indonesia has about 881,3 million tons nickel reserve which are scattered in eastern region of Indonesia such as Sulawesi, Maluku, Kalimantan, and Papua. To obtain nickel in industrial level, reduction process uses coal as its reductor. However, the usage of coal causes tons of greenhouse gas emissions. In 2019, for every ton of ferronickel, 70 ton of carbon emission is produced. One of the alternatives to reduce the reduction process emission is the usage of biomass as its reductor. However, biomass itself does not have the same amount of carbon with coal. Therefore, the usage of biomass as a reductor is not typically used in the industry. To solve those problems, torrefaction of biomass is done and is mixed with coal to reduce emission. This experiment was done by torrefying palm kernel shell (PKS) for one and three hours at 200 and 300?. Next, the biomass and coal was mixed to be a reductor with a certain composition such as 100% coal, 100% biomass, and 50% coal + 50% biomass. The reductor and the saprolite ore was mixed with the composition reductor of stoichiometry and twice stoichiometry as well as 8 gram of saprolite ore. The mixture was reduced at 900? for three hours and was continued with smelting process at 1550?. The result was analyzed with optical microscope and scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS). The temperature variation of torrefied biomass is not significantly influenced the fixed carbon content of biomass. However, the time variation of torrefied biomass is significantly influenced the fixed carbon content of biomass. The Fe content after going through the reduction and smelting process is around 71% to 87%. Meanwhile, the Ni and Cr content is 5-6% and 2,9-4,4% respectively. The Fe and Ni content is increasing alongside with the escalation of biomass content in the reductor. However, the Cr is decreasing along with the increase of biomass content in reductor. Meanwhile, the nickel yield itself is 100% on every kind of reductor that is used. It shows that biomass can be a sufficient reductor to reduce nickel saprolite ore.