Extraction of Limonitic Nickel Ore using Dissolved SO2-Air

• Main Author: Ade Rangga (NIM : 13013092), Dye
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21855
• Institution: Institut Teknologi Bandung

Nickel is one of metal with many applications in our daily life. The amount of limonite nickel ore in Indonesia is higher than saprolite nickel ore. However, limonite nickel processing using common technology such as high pressure acid leaching isnot economically feasible because it requires high capital investment cost for its equipment, whereas the ore’s nickel-content is very low (less than 1.5% w/w). This research about extraction of limonite nickel ore using dissolved SO2-air is expected to solve problem about limonite extraction, because this extraction method does not require any complex equipments and operated at atmospheric pressure. Pre-treatment is one of method to increase yield of nickel. Previous research’s pre-treatment was done byroasting limonite nickel ore using furnace at 650oC for 1 hour, but nickel yield from that method was still low. In this research, extraction was done for 180 minutes with acidity level variation at pH 2, 3, 4, and 5 and temperature of 30, 55, and 80oC. Pre-treatment performed in this study areroasting using furnace and alkali-roasting using Na2CO3. Method that is used to analyze nickel yield from extraction results is AAS, XRD for mineralogical analysis, and TGA-DSC for analysis of energy and mass changes. It was found that the highestnickel yield is at pH 2 and temperature 80oC. Extraction results of pH 2 when compared to pH 3 at 80oC for alkali-roasting pre-treatment method using Na2CO3 can increase the nickel’s yield from 28.17% to 100% and for pre-treatment of roasting using furnace can increase nickel gain from 20.42% to 61.39%. However, at pH 2, the selectivity of nickel over iron decreased from 96272 to 534 for pre-treatment of furnace heating and from 1.8 to 1 for alkali-roasting pre-treatment using Na2CO3. The kinetic modeling used was shrinking core model (SCM). This model is suitable for alkali-roasting pre-treatment using Na2CO3. The reactionkinetics are controlled by diffusion ash with reaction rate constant of 8 × 10-5 m s-1.