The Degree of Lithium (Li) Stability Compared to Calcium (Ca) and Magnesium (Mg) from Low Lithium Grade Brine Water with Addition of Limestone and Oxalic Acid

Abstract

The purpose of this study was to investigate whether lithium was precipitated along with the removal of Ca and Mg elements from brine water using limestone and oxalic acid. The first stage was Mg removal by adding CaO at room temperature for 3 hours. The second stage was the Ca removal by adding oxalic acid at a ratio of 2; 3; 4; 5; 10; 15; 20; 30; and 40 ml / 100 ml brine water and pH : 0, 1, and 4 at room temperature for 3 hours. The results showed the most optimal addition of CaO was 20 gr/1 l of brine water with the Mg element can be removed above 99 %, while Li was only reduced by about 1 ppm, and the Ca content only increased by around 28 ppm. The use of oxalic acid will also reduce the amount of lithium besides the Ca removal in the form a precipitate of calcium oxalate. The use of oxalic acid at pH 0 and 4 would reduce the Li content more than at pH 1. At the use of oxalic acid up to 40 ml at pH 1, brine water still contained about 78% Li element.