Method of preparing lithium salts
AssigneeFMC Corporation
InventorVijay Chandrakant Mehta
Life of this patent
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Abstract
The present invention provides an inexpensive process for the preparation of lithium salts of formula LiX having a desired or required level of purity using lithium chloride and lithium sulfate. In the process of the invention, a lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof is reacted with NaX or KX in a aqueous, semiaqueous, or organic solution and the precipitated salts are removed to obtain the LiX solution of desired purity. Preferably, a semiaqueous solution containing water and an organic solvent is used at some point in the reaction. The process of the invention eliminates the use of highly acidic materials and thus reduces the cost of raw materials and the need for specialized equipment.
Claims25
A method for preparing a lithium salt of formula LiX, comprising:
- reacting lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof with NaX or KX in an aqueous solution;
- adding an organic solvent to the aqueous solution to produce a semiaqueous solution;
- and
- removing the precipitated solids from the semiaqueous solution to obtain a LiX solution.
A method for preparing lithium nitrate or lithium bromide, comprising:
- reacting lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof with NaNO3, NaBr, KNO3 or KBr in an aqueous, semiaqueous or organic solution;
- and
- removing the precipitated solids from the solution to obtain a LiNO3 or LiBr solution.
A method for preparing a lithium salt of formula LiX, comprising:
- reacting lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof with NaX or KX salt in an aqueous solution;
- removing the precipitated solids from the aqueous solution;
- drying the aqueous solution and recovering the dried salts;
- preparing an organic solution comprising the salts from said drying step;
- and
- removing the precipitated solids from the organic solution.
A method for preparing a high purity lithium salt of formula LiX comprising:
- dissolving lithium chloride, lithium sulfate, or a mixture thereof and a NaX salt, KX salt, or a mixture thereof, in an aqueous solution;
- filtering the solution to remove the sodium and potassium salts;
- adding an organic solvent selected from an aliphatic ketone, an aliphatic alcohol and a mixture thereof, to form a semiaqueous solution;
- filtering the precipitated sodium and potassium salts from the semiaqueous solution;
- removing the organic solvent from the solution;
- and
- recovering the resulting LiX solution.
A method for preparing high purity lithium nitrate or lithium bromide, comprising:
- dissolving lithium chloride, lithium sulfate, or a mixture thereof and a NaX salt, KX salt, or a mixture thereof, wherein X is nitrate or bromide, in an aqueous solution;
- filtering the solution to remove the sodium and potassium salts:
- adding an organic solvent selected from an aliphatic ketone, an aliphatic alcohol and a mixture thereof, to form a semiaqueous solution;
- filtering the precipitated sodium and potassium salts from the semiaqueous solution;
- removing the organic solvent from the solution:
- and
- recovering the resulting lithium nitrate or lithium bromide solution.
A method for preparing lithium nitrate or lithium bromide, comprising:
- reacting lithium salt selected from lithium chloride, lithium sulfate, and combinations thereof with NaX or KX, wherein X is nitrate or bromide, in an aqueous solution;
- adding an organic solvent to the aqueous solution to produce a semiaqueous solution;
- and
- removing the precipitated solids from the semiaqueous solution to obtain a LiX solution.
Dependencies are inferred from the claim text.