Method for preparing high-purity lithium carbonate from brine
The present disclosure provides a method of preparing highly pure lithium carbonate from brine. The method includes adding an adsorbent to the brine, from which the magnesium ions Mg 2+ have been removed, to adsorb lithium ions Li + to the adsorbent, followed by providing the adsorbent having the lithium ions Li + adsorbed thereto to a strong acid solution to desorb the lithium ions Li + from the adsorbent; enriching the strong acid solution in which the lithium ions Li + are desorbed from the adsorbent; and obtaining lithium carbonate Li 2 CO 3 through chemical reaction between the lithium ions Li + in the enriched solution and a carbonate precursor.
1. A method of preparing lithium carbonate, comprising:
removing magnesium ions Mg 2+ from brine;
adding an adsorbent to the brine, from which the magnesium ions Mg 2+ have been removed, to adsorb lithium ions Li + to the adsorbent, and then contacting the adsorbent with a strong acid solution to desorb the lithium ions;
enriching the strong acid solution containing the desorbed lithium ions; and
obtaining lithium carbonate Li 2 CO 3 by chemical reaction between the lithium ions Li + in the enriched solution and a carbonate precursor.
2. The method of claim 1 , wherein the removal of magnesium ions comprises precipitating the magnesium ions Mg 2+ to produce a magnesium precipitate selected from the group consisting of magnesium oxalate and magnesium carbonate.
3. The method of claim 1 , wherein the removal of magnesium ions comprises precipitating the magnesium ions Mg 2+ to produce a precipitate of magnesium hydroxide.
4. The method of claim 3 , wherein the removal of magnesium ions comprises precipitating the magnesium ions Mg 2+ using one selected from the group consisting of NaOH, KOH and CaO.
5. The method of claim 1 , wherein the adsorbent comprises manganese oxide or aluminum oxide.
6. The method of claim 1 , wherein the strong acid is selected from the group consisting of hydrochloric acid, sulfuric acid and nitric acid.
7. The method of claim 1 , wherein the enrichment of the strong acid solution comprises enriching the strong acid solution to have a concentration of lithium ions Li + of 4 wt % or more.
8. The method of claim 7 , wherein the enrichment of the strong acid solution comprises enriching the strong acid solution to have a concentration of lithium ions Li + of 6±0.5 wt %.
9. The method of claim 1 , wherein the enrichment of the strong acid solution is performed using sunlight.
10. The method of claim 1 , further comprising: neutralizing the strong acid solution after desorption of the lithium ions or after the enrichment of the strong acid solution.
11. The method of claim 1 , wherein the carbonate precursor comprises carbon dioxide CO 2 .
12. The method of claim 1 , wherein the brine is synthetic brine containing lithium, magnesium, sodium, potassium and boron in the form of ionic components.
13. The method of claim 7 , wherein the enrichment of the strong acid solution comprises enriching the strong acid solution to have a concentration of lithium ions Li + of 6 wt % or more.