EFFECT OF TEMPERATURE PATTERNS ON IRON NUGGET FORMATION OF LATERITE NICKEL ORE LEACHING RESIDUE USING PALM KERNEL SHELL AS REDUCING AGENT

• Main Author: Riva'i, Saefull
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/72619
• Institution: Institut Teknologi Bandung

In 2022, global nickel mining production increased by about 20% compared to the previous year. The nickel production through hydrometallurgy process produces leaching residues that are harmful to the environment. On the other hand, leaching residue has an iron content of up to 38.1%. However, the high sulfur content in leaching residue poses a challenge to its use as a raw material for the iron and steel industry. The palm oil industry in Indonesia has experienced rapid growth over the last 20 years. The content of fixed carbon in palm kernel shell (PKS) has potential to be used as a reducing agent in the metal refining process. A series of experiments were carried out with variations in temperature patterns and types of briquette used, composite (25% PKS) and non-composite (0% PKS) briquette. The reduction process was carried out in a muffle furnace with initial isothermal temperature variations of 1000, 1100, 1200, 1300, and 1450oC. The temperature was increased to the final isothermal temperature of 1450oC for 60 minutes and held for 30 minutes. The reduction results were analyzed using ImageJ software to determine the diameter and cross-sectional area of the metal. Furthermore, the results of the reduction were characterized using a scanning electron microscope–energy dispersive spectroscopy (SEM-EDS) to determine chemical composition of the metal and slag. Based on the experimental results, an increase in the initial isothermal temperature from 1000 to 1450oC at all temperature patterns affects the increasing average diameter and average cross-sectional area of the metal from composite and noncomposite briquette. The increase in initial isothermal temperature also affects the decrease in iron content and increase in sulfur content in the metal from the composite and non-composite briquette. Meanwhile, in slag, the higher of the initial isothermal temperature increases the oxygen content which indicates that more metal oxides are reduced. In composite briquettes with an initial isothermal temperature of 1100 to 1450oC, the recovery of iron in the metal decreased. The highest iron recovery is 98.01% for composite briquettes that were obtained at an initial isothermal temperature of 1100oC. Furthermore, in non-composite briquettes with an initial isothermal temperature of 1000 to 1200oC, the recovery of iron in the metal decreased. While at the initial isothermal temperature of 1200 to 1450oC there is an increase of iron recovery in the metal. The highest iron recovery is 82.39% for non-composite briquettes that were obtained at an initial isothermal temperature of 1000oC.