STUDY OF UTILIZATION OF BAUXITE RESIDU AS RAW MATERIAL FOR IRON PRODUCTION WITH PLASMA SMELTING TECHNOLOGY

• Main Author: Rizqullah, Helmy
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/57883
• Institution: Institut Teknologi Bandung

Aluminum is produced from bauxite ore as the primary source. The alumina contained from the ore is extracted through the Bayer process. Aluminum is produced by reducing alumina by the Hall-Heroult process. The by-product of the Bayer process is red mud. For one ton of aluminum produced from the bauxite ore, two to five tons of red mud is produced. The red mud affects negatively towards the health of the surrounding vegetation. The substantial amount, as well as the negative impact of red mud, is a problem that needs to be solved. The red mud contains a high amount of iron oxide, approximately 30-60%, and it has the potential to be used as a raw material to produce iron. Various studies have been done to obtain iron metal from the red mud. One of the technologies that is being studied is plasma melting. Plasma melting utilizes electric energy and the energy generated from gas ionization to fulfill the energy requirement from the reduction process. A series of experiments to produce iron metal from red mud has done by plasma smelting technology with variating the amount of CaCO3 and the usage of nitrogen and carbon dioxide gas as the plasma source. The variation in addition of CaCO3 is conducted to adjust the ratio of CaO/SiO2 to be in the value of 0,94, 1,42, and 1,92. The metal and slag from the melting result were then separated. The obtained metal was then analyzed using SEM-EDS and spectrometer to determine the composition of the metal formed. The obtained slag was then analyzed using ICP-OES and XRD to determine the chemical composition as well as minerals. The metal obtained was dominated by Fe, while there were also C, Si, and Ti in the mixture. On the usage of carbon monoxide gas, there was an increase of the reduced Si element into the metal. The slag contained the minerals tridymite, melilite, C2S, C3S, katoite, gehlenite, melilite, and mullite. From the smelting process without addition, the fayalite mineral was obtained from the slag. The metal yield was decreased with the addition of additives, however, the iron level within the metal increased.