THE REDUCTION OF MIXED LATERITE NICKEL ORE AND MANGANESE ORE TO PRODUCE FERROMANGANESE-NICKEL METAL

• Main Author: Levina, Gina
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/39964
• Institution: Institut Teknologi Bandung

Stainless steel is a type of alloy steel that is resistant to corrosion. One of the metals used in stainless steel is nickel. The demand for stainless steel in the world is increasing by 4.9% per year. The production of stainless steel in the world is dominated by China. Even though the facts show that Indonesia is among the top five in the world in nickel mining. One of the most widely used types of stainless steel is 200 series. This type of stainless steel is widely applied for sinks, food processing equipment, ovens, doors, windows, and others. Series 200 stainless steel has a nickel content between 1-6% and manganese content between 5.5-15%. In this research, a study of the reduction of mixed laterite nickel ore and manganese ore was carried out to produce ferromanganese-nickel metal which are expected to be the raw material for making 200 series stainless steel or high-manganese steel. The experiments were carried out by varying the addition of coal in composite briquettes from 15%, 20%, 25%, and 30%, with the addition of fixed manganese ore which is 50% of the laterite nickel ore base. The next experiment was carried out with 40% and 60% addition of manganese ore. The reduction process was performed with the isothermal-gradient temperature method which consists of 3 stages. The first stage was the isothermal stage at a temperature of 1000oC, the next stage was followed by a gradient towards 1450oC, 1500oC, and 1550oC, and the final stage was the final isothermal stage. The total reduction time given was 140 minutes. The metal particles and slags formed were then observed by optical microscopy, then analyzed by EPMA-WDS and SEM-EDS to get the content and distribution of elements in the metal and slag formed. The results showed that the optimum coal addition was 15% at the final isothermal temperature of 1550oC. The addition of manganese ore increased the ratio of the metal weight compared to the weight of the input ore. The addition of 60% manganese ore had a significant effect in decreasing Fe content and increasing Mn content in metal. At the final isothermal temperature of 1550oC, the contents of Fe, Ni, and Mn at the addition of 40% manganese ore were 63.50%; 9.02%; dan 10.86%, with a ratio of the metal weight to the weight of the input ore of 0.040. The contents of Fe, Ni, and Mn at the addition of 50% manganese ore were 64.15%; 8.99%; and 10.90%, with a ratio of the metal weight to the weight of the input ore of 0.045. The contents of Fe, Ni, and Mn at the addition of 60% manganese ore were 56.51%; 8.02%; and 19.88% with a ratio of the metal weight to the weight of the input ore of 0.049.