The electrolysis technique without a salt bridge to reduce magnesium level and the Mg/Li ratio from brine water at various electrolysis duration

Currently, the world's lithium reserves are over 70% present in the form of brine water. A series of studies have been conducted on brine water found in Gunung Panjang spring, Ciseeng, Bogor to determine the effect of the electrolysis process on the reduction of magnesium elements and the Mg/Li ratio in brine water. In this study, the process of electrolysis of brine water was carried out without a salt bridge using graphite electrodes at a large voltage of 15 V. The electrolysis process was carried out for 60 hours and brine filtrate samples were taken every six hours. The characterization tests were performed on samples including ICP-OES, XRD, and SEM-EDS tests. Based on the research result, it was known that the electrolysis process was able to reduce the magnesium concentration in brine water with increasing electrolysis time. The percentage of Mg levels that decreased in brine water was 58.74% at 60 hours. The Mg/Li ratio in brine water also decreased from 10.01 to 6.01. The interpretation of the XRD pattern using Match-3 software showed that the residue phase deposited during the electrolysis process was dominant in the form of Mg(OH2 (brucite) and Ca(OH2 (portlandite), while other minor phases were identified as KCl (sylvite), LiCl and NaCl (halite), while SEM-EDS analysis showed Ca, O and Mg elements are known to have the most even distribution of elements on the surface of the sample among other elements. The success of this research is a good step to preparing raw materials for manufacturing lithium carbonate precursors. Further research needs to be explored in an effort to reduce magnesium levels and the Mg/Li ratio by increasing the electrolysis duration and adding a salt bridge to separate anode and cathode.