SEPARATION OF RARE EARTH ELEMENTS USING ELECTRODIALYSIS WITH COMPLEXATION REACTION

• Grant number: 24/04555-1
• Support Opportunities: Scholarships in Brazil - Master
• Start date: September 01, 2024
• End date: January 31, 2026
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Denise Crocce Romano Espinosa
• Grantee: Patrick de Oliveira Wecchi
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Associated research grant: 19/11866-5 - Development of innovative processes for the recovery of critical metals, AP.TEM

Abstract

The rare earth elements (REEs) are critical for Japan, USA, China, Canada, and the European Union. They are present in magnets, batteries, polishers, metal alloys, glasses, and ceramics. REEs are important for green energy generation with lower CO2 emissions and are used in ecological catalysts. The recovery of REEs from secondary sources is a goal to meet the demand for these metals and is of paramount importance. This project aims at separating REEs through electrodialysis (ED) with a complexing agent to enhance membrane selectivity. The advantage of ED is that it does not require a regeneration step and allows for ion reuse. The sample will be a synthetic liquor similar to the liquor resulting from the acid leaching of tin mining slag. The solution will be prepared with both light and heavy REEs (La, Nd, Y, Pr, and Gd). These elements were chosen due to their presence in secondary mining sources and electronic devices. Ion transport via ED will be studied. The performance of EDTA as a complexing agent will be evaluated. The effect of pH will be studied at values of -0.5, 0.5, 1.0, 1.5, and 2.0. The current studied will be 15 mA, 200 mA, 300 mA, and 400 mA. Samples will be studied over a period ranging from 30 minutes to 100 hours. The solution will be analyzed using ICP-OES, AAS, EDXRF, and WDXFR. In this way, this project analyzes at the molecular scale the separation of ions with potential application at a semi-pilot scale.