Abstract: Lithium carbonate can be efficiently produced from a brine by (i) removing the boron therefrom, (ii) diluting the boron-free brine, (iii) removing magnesium from the diluted brine, and (iv) adding sodium carbonate to thereby precipitate lithium carbonate. By diluting the boron-free brine, the co-precipitation of lithium carbonate during the magnesium removal process is greatly reduced, thereby improving the recovery and purity of the lithium carbonate.

Abstract: Boron is effectively removed from brine, including lithium-containing brines, by acidifying the brine to a pH of 0.1 to 6.0 and then contacting the brine with an extraction medium comprising at least a diol having 6 to 20 carbon atoms in an aromatic solvent. The extraction medium may also contain high aliphatic alcohols and/or a phase modifier. The boron can be stripped from the boron rich extractant medium by a re-extraction stage utilizing an aqueous alkaline solution.

Abstract: A process for extracting boron from brines of natural or industrial salt mines which includes the steps of reacting borates contained in the brine with a solution of hydrochloric acid and forming boric acid, cooling the brine containing boric acid, separating the boric acid from the remainder of the brine to obtain impure boric acid and brine having a low boron content, washing the impure boric acid with distilled or demineralized water to obtain purified boric acid, and drying the purified boric acid. Boric acid crystals thus obtained are washed and recrystallized. The remaining boron in the low boron content brine can be removed by extraction in a paraffin solvent. The boron can then be re-extracted from the solvent and converted to boric acid for isolation and purification as above.