Production of lithium compounds directly from lithium containing brines

1. A continuous process for directly preparing lithium chloride from lithium containing brines comprising:

preparing a brine containing about 6.0 wt % lithium and further containing other ions such as sodium, magnesium, calcium, and sulfates naturally occurring in brines;

adding a solution of CaO and sodium carbonate to remove calcium and magnesium as precipitates;

filtering to remove the calcium and magnesium precipitates to yield a purified 6% lithium brine;

cooling the purified 6 wt % lithium brine to a temperature of from minus 30 to +10° C. to reduce the sodium content to not more than 0.05 wt % Na;

adjusting the pH of the reduced sodium solution to acidic, preferably to pH 4 with hydrochloric acid;

adding a barium solution to remove any sulfate as barium sulfate;

adding lithium hydroxide to the barium treated solution to raise the pH to less than 10, preferably 6-7;

adding an aqueous oxalate mixture comprising lithium oxalate and calcium oxalate to further precipitate calcium as calcium oxalate;

adjusting the pH to slightly above pH 10;

filtering to remove calcium oxalate;

passing the solution through an ion exchange column to remove any divalent and trivalent cations;

adjusting the pH to from 6 to 8, preferably 7; and

charging the purified brine into a crystallizer to produce anhydrous low calcium, low magnesium lithium chloride crystals.

2. The method of claim 1 , wherein to reduce the sodium to less than 0.05 wt % in the 6 wt % lithium brine is preferably below 0° C., and more preferably minus 15° C. to minus 20° C., preferably from minus 30 to below minus 20° C.

3. The method of claim 1 , wherein said ion exchange column comprises Amberlite IRC-718 as a cation exchange resin.

4. Lithium chloride produced by the process of claim 1 having not greater than 0.11 wt % sodium as an impurity.

5. The lithium chloride of claim 4 having the following composition described below:

LiCl

min 99.0 wt %

Na

<0.11 wt %

Ca

<0.0100 wt %

Mg

<0.0003 wt %

Ba

<0.0100 wt %

SO4

<0.0100 wt %.

6. The lithium chloride obtained in claim 1 after additional purification step using an ion exchanger has calcium less than 15 ppm and magnesium less than 1 ppm.