Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Assessment of electric field assisted mining of lanthanum from soils
Submission Author:
Carolina Mocelin Gomes Pires , PR
Co-Authors:
Carolina Mocelin Gomes Pires, Alexandra Ribeiro, Maria José Jerônimo de Santana Ponte, Haroldo Ponte
Presenter: Carolina Mocelin Gomes Pires
doi://10.26678/ABCM.COBEM2023.COB2023-2391
Abstract
Rare earth elements (REEs) are essential for the development of green and sustainable technologies. They are used in different areas, such as oil and automobile industry, metallurgy and medicine. The main techniques for REEs extraction are given by hydrometallurgical processes, which can present a high environmental impact, being on the opposite side of decarbonization activities and reduction of greenhouse gases. Hence, the use of environmentally friendly techniques for improving REEs removal and recovery is needed. Electric field assisted mining is an eco-friendly electrokinetic process to recover metallic species from different matrices, including soils. This technique consists of the application of an electric potential gradient between electrodes, aiming to promote the mass transport of ionic species. Therefore, considering the maintenance of the supply chain for lanthanum, which is also considered a critical raw material, the aim of the present work was to evaluate the extraction of lanthanum from different soils applying the electric field assisted mining technique. To this end, two different samples of soil were used, in which S1 presented a sandy clay texture and S2 a sandy clay loam one. The electromining experiments (E1 and E2) were conducted for 600 h, applying an electric field of 1.0 V cm-1 and using acetic acid as electrolyte at a concentration of 0.10 mol L-1. The results showed that lanthanum ions presented only migrational flows towards the cathodic chamber, in both tests. At the end of the experiments, electromining efficiencies were obtained, which resulted in 41.7% of La3+ in experiment S1, and 50.8% of La3+ in experiment S2. Although experiment S2 presented a higher removal, this experiment achieved a steady removal after 450 h. On the other hand, experiment S1 presented an increasing trend, which indicates that it can achieve higher values of removal over time. Furthermore, the extraction behavior can also be associated with the soil texture, sandy clay and sandy clay loam. Considering these results, electric field assisted mining technique presents itself as an eco-friendly and viable technique for rare earth elements extraction.
Keywords
eco-friendly technique, electromining, rare earth elements, green extraction
