A CONCEPTUAL STUDY OF BIOEXTRACTION OF RARE-EARTH ELEMENTS FROM PHYTHOMINING PROCESS: A COMPREHENSIVE REVIEW

• Main Author: Zhurrahman Mirza Utama, Arif
• Format: Final Project
• Language: Indonesia
• Subjects: Metalurgi
• Online Access: https://digilib.itb.ac.id/gdl/view/51354
• Institution: Institut Teknologi Bandung

Rare earth elements (REEs) are one of the in-demand commodities in recent years due to their application in modern technology, such as permanent magnets, catalysts, metal alloys, and batteries. The production of rare earth elements can be either by pyrometallurgical and hydrometallurgical methods. However, these techniques use dangerous compound such as sulfuric acid. Therefore, the attention to a biological process in REEs extraction rise. The method covers the usage of plants to extract REEs from soil, called phytomining, and microorganisms to leach and recover REEs. Currently, the investigations are only focused only on a single part. In this review, REEs' biological process was comprehensively discussed, based on the studies and papers published. Also, the factors affecting phytomining performance were discussed. In the end, a potential biological process of REEs from soil was proposed. Before discussing the main idea, sources from various research publications regarding phytomining of REEs and its mechanism were collected and reviewed. Then, the collection of sources about route of REEs' biorecovery process was carried out, including bioleaching, bioadsorption, and bioprecipitation. Subsequently, discussion of the factors that influence pythomining and biorecovery process was carried out. The results of the review show that the optimum value of each factor in phytomining and biorecovery process was affected by the type of soil type, soil conditions, and the microorganisms used. Based on various research sources, it can be concluded that the process of phytomining of rare earth elements by hyperaccumulator plants can be influenced by pH, reduction potential, and soil type. In the bioleaching process, the mechanisms might involve the combination of redoxolysis, acidolysis, and complexolysis. The ecofriendly processing route for rare earth elements consists of phytomining, preparation of plant that has rich concentration of rare earth elements, bioleaching, biosorption, bioprecipitation and calcination. This route is expected to reduce environmental pollution and lower the processing cost for low-grade REEs resources.