METHOD FOR PRODUCING LITHIUM CHLORIDE, AND LITHIUM CARBONATE

1 . A method for producing lithium chloride aqueous solution comprising:

introducing calcium chloride into a slurry containing a solvent and lithium phosphate; and

obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.

2 . The method of claim 1 ,

wherein, the solvent of the slurry is water or deionized water.

3 . (canceled)

4 . The method of claim 1 ,

in the step of introducing calcium chloride into the slurry containing the solvent and lithium phosphate, wherein the lithium phosphate is derived from lithium in brine, lithium in the waste battery, lithium in the ore, or a combination thereof.

5 . The method of claim 1 ,

wherein, a step of obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate is:

obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound, unreacted lithium phosphate particle, and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.

6 . The method of claim 1 ,

wherein the method for producing the lithium chloride aqueous solution is characterized in that the reaction conditions are neutral or basic conditions throughout all the steps.

7 . (canceled)

8 . The method of claim 1 ,

wherein, the lithium phosphate is not obtained by a process of leaching through strong acid treatment.

9 . The method of claim 1 ,

wherein, a concentration of lithium ions in the lithium chloride aqueous solution is 10,000 ppm or more.

10 . The method of claim 1 ,

in the step of obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate,

the reaction rate of the lithium phosphate in the reaction of the lithium phosphate with calcium chloride is 90% or more.

11 . The method of claim 1 , further comprises:

injecting the washed filtrate into the slurry containing the solvent and lithium phosphate so as to recover residual lithium in the washed filtrate after washing the obtained chloroapatite precipitate with water,

after obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.

12 . The method of claim 1 , further comprises:

injecting the washed filtrate into the lithium chloride aqueous solution obtained by the step of obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate, so as to recover residual lithium in the washed filtrate after washing the obtained chloroapatite precipitate with water,

after obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.

13 . The method of claim 1 ,

in the step of introducing calcium chloride into a slurry containing a solvent and lithium phosphate,

wherein an amount of the introduced calcium chloride is 1.500 times or more and 2.334 times or less as much as the lithium phosphate based on the molar amount.

14 . The method of claim 1 ,

in the step of obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and'lithium phosphate,

the reaction temperature is 20° C. or more, and 105° C. or less, and the reaction pressure is 0 bar or more and 1.01325 bar or less.

15 . The method of claim 1 ,

in the step of obtaining a precipitate of chloroapatite which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate,

the reaction temperature is 100° C. or more, and 250° C. or less, and the reaction pressure is

1 . 01325 bar or more and 40 bar or less.

16 . A method for producing lithium carbonate comprising:

preparing a lithium chloride aqueous solution; and

obtaining lithium carbonate and a filtrate by adding sodium carbonate to the lithium chloride aqueous solution;

wherein, a concentration of lithium ions in the lithium chloride aqueous solution is 10,000 ppm or more.

17 . The method of claim 16 ,

in the step of preparing a lithium chloride aqueous solution,

wherein, the lithium in the lithium chloride is derived from lithium in brine, lithium in the waste battery, lithium in the ore, or a combination thereof.

18 . The method of claim 16 , further comprises:

obtaining lithium phosphate by adding a phosphorus supplying material to the filtrate,

after the step of obtaining lithium carbonate and a filtrate by adding sodium carbonate to the lithium chloride aqueous solution.

19 . The method of claim 16 , further comprises:

injecting the washed filtrate into the lithium chloride aqueous solution in the step of preparing a lithium chloride aqueous solution, so as to recover residual lithium in the washed filtrate after washing the obtained lithium carbonate with water,

after the step of obtaining lithium carbonate and a filtrate by adding sodium carbonate to the lithium chloride aqueous solution.

20 . The method of claim 16 ,

in the step of obtaining lithium carbonate and a filtrate by adding sodium carbonate to the lithium chloride aqueous solution,

the sodium carbonate is added in such an amount that the molar ratio (lithium ion:sodium ion) of the lithium ion in the lithium chloride aqueous solution to the sodium ion in the sodium carbonate is 1:0.8 to 1:1.2.

21 . The method of claim 16 ,

in the step of obtaining lithium carbonate and a filtrate by adding sodium carbonate to the lithium chloride aqueous solution,

a reaction temperature is 20° C. or more and 100° C. or less.

22 . The method of claim 16 ,

in the step of preparing a lithium chloride aqueous solution,

wherein the lithium chloride aqueous solution is produced introducing calcium chloride into a slurry containing a solvent and lithium phosphate; and obtaining a precipitate of which is a poorly soluble phosphoric acid compound and a lithium chloride aqueous solution by reacting lithium phosphate and calcium chloride in the slurry containing the solvent and lithium phosphate.