STUDY ON THE NICKEL MATTE PRODUCTION FROM SAPROLITIC NICKEL ORE USING COAL REDUCTANT AND GYPSUM ADDITIVE AT TEMPERATURE OF 1400-1600?

• Main Author: Satritama, Bima
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/64775
• Institution: Institut Teknologi Bandung

Most nickel is produced from its primary sources, namely laterite nickel ore and sulfide. Nickel sulfide ores are generally processed through the pyrometallurgical route to produce nickel mate, while laterite nickel ores are generally processed through the pyrometallurgical route to produce iron-nickel alloys. However, the increasing world demand for first-class nickel has encouraged the industry to also produce nickel mate from laterite nickel ore. Currently, various industries, such as the chemical industry, phosphate fertilizers, and steam power plants produce high amounts of gypsum by-products every year. Gypsum is rich in CaSO4 which can be used as an alternative source of sulfur for the manufacture of nickel mate. This study aims to study the effect of process temperature, addition of coal reducing agent, and sulfurizing agent in the form of gypsum in the process of making nickel mate from saprolite nickel ore. The experiment was initiated by conducting a thermodynamic simulation using FactSage 8.0 software with reference to the results of the characterization of the composition of saprolite nickel ore and coal. After that, saprolite nickel ore, coal, and gypsum are mixed and formed into briquettes by varying the percentage addition of coal and gypsum to the weight of the saprolite nickel ore by 5, 10, and 20%, respectively. Next, the reduction process was carried out in a horizontal tube furnace for two hours in an inert state by exhaling 1 L/minute of argon gas at various temperatures, namely 1400, 1500, and 1600?. The results of the reduction in the form of metal/mate and slag were analyzed for microstructure using an optical microscope and the composition was measured using scanning electron microscopy-electron dispersive spectroscopy (SEM-EDS). The average metal/mate content produced in this experiment was 11.19% Ni, 72.42% Fe, and 10.7% S. The nickel content in the metal/mate phase decreased with the addition of coal, while the sulfur content in the metallic/mate phase decreased with the addition of coal. metal/mate increased with increasing addition of gypsum. The variation of the addition of coal and gypsum that produces the highest nickel content is the addition of 5% coal + 5% gypsum with an average metal/mate composition of 18.03% Ni, 72.66% Fe, and 9.31% S for the process temperature. between 1400–1600?. The nickel content increases as the process temperature increases from 1500 to 1600?. However, the process temperature that produced the highest nickel content in this experiment was 1400? with an average metal/mate composition of 13.67% Ni, 72.57% Fe, and 11.64% S for the addition of coal and gypsum each between 5–20%. Based on the results of the analysis of the slag in the experimental product, two things were studied, namely the increase in the addition of coal causes the FeO content in the slag to decrease and the increase in the addition of gypsum causes the CaO content in the slag to increase.