Method for producing high-purity lithium carbonate
AssigneeKorea Resources Corporation
InventorsDong Jun Kang, Mi Hee Yoon, Jeon Woong An
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Abstract
Disclosed is a method for producing high-purity lithium carbonate. The method includes: removing magnesium and boron from a brine; separating and removing the remaining magnesium and calcium; concentrating the resulting brine by spray drying to form a powder; washing the powder to concentrate lithium; and carbonating the lithium ions with sodium carbonate (Na2CO3).
Claims3
A method for producing high-purity lithium carbonate from a brine wherein a content of magnesium ions and a content of sulfate ions in the brine are 20 times higher and 26 times higher than a content of lithium ions, respectively, the method comprising the steps of:
- removing magnesium and boron from the brine using calcium hydroxide (Ca(OH)2), wherein the calcium hydroxide reacts with the magnesium to precipitate magnesium hydroxide (Mg(OH2), and the boron is adsorbed to a surface of the magnesium hydroxide;
- separating and removing remaining magnesium and calcium in the brine using sodium oxalate (Na2C2O4), wherein the sodium oxalate reacts with the remaining magnesium to form magnesium oxalate (Mg2C2O4) and reacts with the calcium to form calcium oxalate (Ca2C2O4) and the magnesium oxalate and the calcium oxalate are removed from the brine by a solid-liquid separation process;
- concentrating a resulting brine, which is obtained after the removing magnesium and boron step, and the separating and removing remaining magnesium and calcium step, by spray drying to form a powder;
- washing the powder to concentrate lithium in liquid;
- and
- carbonating lithium ions in the liquid with sodium carbonate (Na2CO3).
Dependencies are inferred from the claim text.