Work

Membrane-Assisted Electrochemical Removal of Mg2+ and Ca2+ from Lithium Brines: Effects of Temperature and Current Density Through a Zeta Potential Approach

Year: 2025

Type: article

Abstract: Understanding surface charge behavior is essential for improving ion separation during lithium brine treatment. This paper investigates the performance of a three-compartment electrodialysis system designed for the selective removal of divalent cations (Mg2+ and Ca2+). The relationship between zeta potential and the recovery of Li+, Na+, and K+ is analyzed. Zeta potential measurements at various pH values showed that Mg(OH)2 particles maintained a positive charge. The system facilitated the precipitation of Mg(OH)2 and Ca(OH)2 via electrochemically generated OH− ions. The specific electrical energy consumption was evaluated for each operating condition. The results showed that the zeta potential of the precipitates was affected by both the current density and temperature. This influenced lithium losses due to brine entrapment within the precipitated solids. At 600 A/m2 and 50 °C, more than 99% of Mg2+ and Ca2+ were removed, and more than 90% of lithium was recovered, with a specific electric energy consumption of 2.58 kWh per kilogram of Li recovered. The system also generates HCl as a valuable by-product, which improves the sustainability of the process. This study provides a new framework for improving the energy efficiency of lithium purification from brines and lithium recovery.

Source: Membranes

DOI: 10.3390/membranes15090250

Authors: Alonso González, Geovanna Choque, Mario Grágeda, Svetlana Ushak

Institution: Universidad de Antofagasta

Language: English

Topic: Membrane-based Ion Separation Techniques

Subfield: Biomedical Engineering

Field: Engineering

Domain: Physical Sciences

SDGs: Clean water and sanitation, Affordable and clean energy, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,654