LITERATURE STUDY OF USING INERT ANODE AS REPLACEMENT OF CARBON ANODE IN THE ALUMINUM ELECTROLYSIS PROCESS

• Main Author: Thierry Wijaya, Christopher
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/55990
• Institution: Institut Teknologi Bandung

Aluminum is one of the most widely used metals because of its various advantages. The aluminum production process from bauxite is divided into 2 stages, the Bayer process and the Hall-Héroult process. Carbon anode is used in the Hall-Héroult process. However, carbon anodes are consumable and can produce greenhouse gas emissions. In this study, information related to the electrolysis of aluminum using inert anode has been studied comprehensively including the development of the commercial aluminum industry, the electrolysis of aluminum with a carbon anode, and the electrolysis of aluminum with an inert anode on a laboratory scale. The purpose of this study is to review the development of research regarding the use of inert anodes and to determine the best candidate for inert anodes for each performance parameter in the aluminum electrolysis process. This literature study was carried out by collecting journals, books, and sources of information about characteristics of aluminum, the Hall-Héroult process, and the use of carbon and inert anodes in aluminum electrolysis. The collected literature is then studied and analyzed to obtain information which is then used to provide a comprehensive discussion to answer the objectives that have been formulated. The results of the literature study indicate that research on the use of inert anodes in the aluminum electrolysis process has been widely carried out. Developments regarding the use of inert anodes are continuously carried out to obtain anode candidates that can replace carbon anodes in industry-scale processes. In addition, several important points were obtained including (1) Ni-Cr anode with intermediate oxide film and surface composite coating (Au, Au-Pt, Au-Pd, and Au-Rh) has the best corrosion resistance with a corrosion rate of 0,55 cm/year; (2) M-40Cr-0,5Ce (M = Fe and Ni) anodes have the best oxidation resistance with oxidation kinetics in the range of 0-0,2 mg/cm2; (3) The smallest cell voltage obtained was 2,3 V, using Ni-Fe-Cr anode; (4) The highest purity of aluminum is obtained when using Ni-Cr metal alloy with an intermediate oxide layer and a composite coating on the surface (Au, Au-Pt, Au-Pd, and Au-Rh) as the anode, with purity >99,99%. This indicates that the use of inert anodes in the aluminum electrolysis process is very interesting to study further as a solution to replace carbon anodes that are consumable and to minimize greenhouse gases produced.