Yttrium extraction from soils by electric field assisted mining applying the evolutionary operation technique

• Published in: Journal of cleaner production Vol. 227; pp. 272 - 279
• Main Authors: Pires, Carolina Mocelin Gomes, Ponte, Haroldo de Araújo, Pereira, Jucélio Tomás, Ponte, Maria José Jerônimo de Santana
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-08-2019
• Subjects: Design of experiments; Electrokinetic phenomena; Electromining; Rare earth elements; Response Surface Methodology; Response Surface Methodology; Rare earth elements; Electrokinetic phenomena; Design of experiments; Electromining
• ISSN: 0959-6526; 1879-1786
• DOI: 10.1016/j.jclepro.2019.04.077

Yttrium is an element of the Rare Earth group. It is mainly used in flat panel displays, alloys, and lasers. It is considered a critical element and there is a concern to meet the global consumer demand. Yttrium is normally available in the mineral form in the earth's crust, and due to the high energy and environmental impact of conventional mining processes, electric field assisted mining arises as an alternative in yttrium extraction. This technique uses electrokinetic phenomena for species' extraction aiming at reducing the environmental impact and energy consumption. The present paper aims at extracting Y3+ by an electric field assisted mining process, using the evolutionary operation technique and response surface methodology to investigate the influence of the electric field and electrolyte concentration variables. The results show that the synergetic operation between a low concentration of acetic acid (0.1 mol L−1) and a high electric field (54.54 V m−1) favored the migration flow of Y3+, resulting in a 42.6% recovery efficiency in the cathode chamber for the 72 h of experiment, with an energy consumption of 259.7 kWh kg−1 of Y3+ removed. Thus, electric field assisted mining is shown to be an economical and environmentally friendly alternative to Y3+ mining.
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•The first case of yttrium extraction via electric field assisted mining.•Using the evolutionary operation (EVOP) technique to improve the process.•The technique presents a low energy cost due to low current density.•Use of an ecofriendly electrolyte.•Experimental technique applicable in situ and ex situ.