GREEN-FERRONICKEL PRODUCTION BY USING HYDROGEN PLASMA SMELTING REDUCTION (HPSR)

• Main Author: Izzul Islam AS, Muh.
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/84599
• Institution: Institut Teknologi Bandung

Indonesia has the largest nickel reserves in the world in the form of laterite ore, with a total of 49 million tons of nickel. Indonesia's nickel production in 2022 reached 1.6 million tons, making Indonesia the world's largest nickel producer, with production dominated by saprolite-type laterite nickel ore. Saprolite nickel ore is generally further processed through pyrometallurgical processes using the Rotary Kiln-Electric Furnace (RKEF) route. Processing through this route represents 95% of the total saprolite nickel ore processing routes worldwide. Processing via RKEF yields ferronickel products with a nickel content of around 20-40%. The utilization of ferronickel has become crucial in various industries worldwide, especially in the iron and steel industry. However, the ferronickel production process through RKEF can emit 24.1 t CO2 e/t ferronickel, making it the ferroalloy industry with the highest emissions. In the context of the 2015 Paris Agreement and the United Nations' commitments to carbon neutrality, the need to reduce these emissions has become very crucial. Over the past few decades, the use of hydrogen as a reductant has begun to be considered because it is much more environmentally friendly. Therefore, many innovations have been made to utilize hydrogen gas on both lab and industrial scales. One of them is through hydrogen plasma smelting reduction (HPSR) technology. Although various studies on metal reduction have revealed the potential of this technology, there have been no laboratory-scale studies that reveal the potential for green ferronickel production through HPSR. In this research, saprolite-type laterite nickel ore was used. The nickel ore was first prepared, including drying and ore characterization. Characterization was performed using X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) to determine the chemical composition of the ore. The experiment continued with briquetting the nickel ore, which would then be placed in the HPSR reactor. The resulting HPSR product was analyzed using Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) to determine and further analyze the chemical composition of the HPSR product. The research results indicate that the laterite nickel ore to be processed through HPSR must first undergo calcination to ensure that the reduction process can proceed effectively. Green ferronickel can be produced rapidly through the HPSR process in just 180 seconds, yielding 70.64% Fe and 23.98% Ni, with no sulfur and phosphorus detected. Consequently, the desulfurization and dephosphorization processes can be eliminated. This green ferronickel product also aligns with the thermodynamic calculations performed using FactSage 8.2 software. Additionally, process parameters such as total gas flow rate and sample weight were also analyzed. It was found that the composition of both the green ferronickel and the slag produced is not significantly affected by the gas flow rates. At the same time, the sample weight has a considerable impact. Therefore, the production of green ferronickel through HPSR shows great potential for further development.